DRIVE UNIT FOR AN ELECTRIC TOOTHBRUSH HANDPIECE, ELECTRIC TOOTHBRUSH HANDPIECE, METHOD FOR PRODUCING OF AN ELECTRIC TOOTHBRUSH HANDPIECE, ATTACHMENT BRUSH FOR AN ELECTRIC TOOTHBRUSH HANDPIECE, AND ELECTRIC TOOTHBRUSH

Abstract

The invention is directed in particular to a drive unit (10) for an electric toothbrush handpiece (2) having a gear unit (11) and an electric motor (16). The gear unit (11) comprises an eccentric (15), a connecting rod (14), a drive shaft (12), and an articulation piece (13) that is securely connected to the drive shaft (12). The electric motor (16) has a motor shaft (16a). Furthermore, the eccentric (15) has a main part (15a) with a main part axis (X.sub.G) and an eccentric pin (15b) which is arranged on the main part (15a) and extends from the main part (15a) in parallel with the main part axis (X.sub.G). The connecting rod (14) has a first bearing (14a), a second bearing (14b), and a rod element (14c) which connects the first bearing (14a) to the second bearing (14b). The articulation piece (13) is secured to the drive shaft (12) and has an articulation pin (13a) which extends in parallel with the drive shaft (12) and counter to the eccentric pin (15b). The main part (15a) of the eccentric (15) is attached along the main part axis (X.sub.G) to the motor shaft (16a) of the electric motor (16) and the eccentric pin (15b) is received by the first bearing (14a) of the connecting rod (14). The articulation pin (13a) of the articulation piece (13) secured to the drive shaft (12) is received by the second bearing (14b) of the connecting rod (14). The invention is additionally directed to an electric toothbrush handpiece (2), a method for producing an electric toothbrush handpiece (2), to an attachment brush head (3) for an electric toothbrush handpiece (2) and to an electric toothbrush (1).

Claims

1. A drive unit for an electric toothbrush handpiece comprising: a gear unit; and an electric motor, wherein the gear unit comprises an eccentric, a connecting rod, a drive shaft and an articulation piece securely connected to the drive shaft, wherein the electric motor has a motor shaft, wherein the eccentric has a main part with a main part axis and has an eccentric pin which is arranged on the main part and extends from the main part in parallel with the main part axis, wherein the connecting rod has a first bearing, a second bearing, and a rod element which connects the first bearing to the second bearing, wherein the articulation piece is secured to the drive shaft and has an articulation pin which extends in parallel with the drive shaft and counter to the eccentric pin, wherein the main part of the eccentric is attached along the main part axis to the motor shaft of the electric motor and the eccentric pin is received by the first bearing of the connecting rod, and wherein the articulation pin of the articulation piece secured to the drive shaft is received by the second bearing of the connecting rod.

2. The drive unit according to claim 1, wherein the main part of the eccentric has one or more recesses configured such that the center of mass of the eccentric is located on the motor shaft of the electric motor.

3. The drive unit according to claim 1, wherein the eccentricity of an eccentric pin axis relative to the main part axis is from 0.2 mm to 3 mm.

4. The drive unit according to claim 3, wherein the eccentricity of the eccentric pin axis relative to the main part axis is from 0.3 mm to 1 mm.

5. The drive unit according to claim 3, wherein the eccentricity of the eccentric pin axis relative to the main part axis is from 1.4 mm to 2 mm.

6. The drive unit according to claim 1, wherein a motor speed in the unloaded state is from 7,000 rpm to 12,000 rpm, preferably from 9,000 rpm to 11,000 rpm.

7. The drive unit according to claim 6, wherein the motor speed in the loaded state is from 3,500 rpm to 10,000 rpm, preferably from 4,000 rpm to 7,000 rpm.

8. The drive unit according to claim 1, wherein the articulation pin of the articulation piece secured to the drive shaft and the eccentric pin have approximately the same diameter.

9. The drive unit according to claim 1, wherein the first and/or second bearing and/or the articulation pin and/or the eccentric pin is/are provided with a sleeve.

10. An electric toothbrush handpiece comprising: a housing; a frame unit; an energy source; a key element; and a drive unit according to claim 1, with a gear unit and an electric motor, wherein the housing surrounds the frame unit, the drive unit and the energy source, the frame unit has at least a gear unit zone, a motor zone, and an energy source zone, wherein the gear unit zone is configured to receive the gear unit, the motor zone is configured to receive the electric motor, and the energy source zone is configured to receive the energy source, the key element is arranged on a front part of the housing and preferably has a key geometry which is configured to couple with a corresponding key coupling geometry of an attachment brush, the energy source is configured to supply the drive unit with energy, and the drive unit is configured to generate a movement of a drive shaft of the gear unit, wherein the drive shaft extends through the key element and preferably has an axis geometry which is configured to couple with a corresponding axis coupling geometry of an attachment brush.

11. The electric toothbrush handpiece according to claim 10, wherein the gear unit zone has a first bearing device for a rear end of the drive shaft.

12. The electric toothbrush handpiece of claim 10, wherein the motor zone is configured to secure the electric motor.

13. The electric toothbrush handpiece according to claim 10, wherein the energy source zone has at least one preload surface configured to secure the energy source.

14. The electric toothbrush handpiece according to claim 10, wherein the frame unit has a coil zone configured to receive a coil carrier which is preferably formed of a soft component.

15. The electric toothbrush handpiece according to claim 14, wherein the coil carrier has a length compensating means, preferably elastic, which supports the frame unit relative to a housing cover of the handpiece.

16. The electric toothbrush handpiece according to claim 10, wherein the frame unit has a print zone which is configured to receive a print plate and which preferably comprises a recess in which the print plate is received.

17. The electric toothbrush handpiece according to claim 10, wherein the key element is configured to latch to the frame unit at its rear end facing the handpiece.

18. The electric toothbrush handpiece according to claim 10, wherein the frame unit comprises a first half-shell-like half and a second half-shell-like half.

19. The electric toothbrush handpiece according to claim 10, wherein the key element has a through bore for the drive shaft and has a second bearing device for a front area of the drive shaft, wherein the second bearing device is preferably arranged at the end of the key element facing away from the handpiece.

20. The electric toothbrush handpiece according to a claim 10, wherein the key element has an internal geometry in which is arranged a sealing element, preferably a bellows seal, which is configured to seal the housing against the drive shaft.

21. The electric toothbrush handpiece according to claim 10, wherein a sealing/damping element made of a soft component is attached to the end of the key element facing the frame unit, which sealing/damping element is configured to seal the housing against the key element and which sealing/damping element is configured to provide a damping bearing for the key element.

22. The electric toothbrush handpiece according to claim 18, wherein the first half-shell-like half and the second half-shell-like half of the frame unit have positioning aids.

23. A method of producing an electric toothbrush handpiece according to claim 10, comprising the following steps: laying out a second half-shell-like half of a frame unit and a first half-shell-like half corresponding thereto; installing a drive unit comprising an electric motor and a gear unit, wherein the electric motor is connected to the gear unit and the electric motor is positioned in a motor zone and the gear unit is positioned in a gear unit zone of the second half-shell-like half and secured therein; installing a rear and a front spring plate in the second half-shell-like half; installing a print plate in a print zone of the second half-shell-like half; installing the first half-shell-like half to the second half-shell-like half; installing a key element to the frame unit, wherein the key element is pushed on via the drive shaft and preferably latches with the frame unit; installing a coil carrier with a charging coil to the frame unit, wherein the coil carrier is attached to a rear end area of the frame unit; establishing electrical connections, wherein wires are preferably routed from the print plate to the electric motor (or vice versa) and the first connecting pieces of the rear and front spring plates and, if necessary, the ends of the cables of the charging coil are soldered to the print plate; installing an energy source, wherein the energy source is received in an energy source zone of the frame unit preferably in a clamped manner between a spring piece of the rear spring element and a spring piece of the front spring element; and sliding in the frame unit into the housing of the handpiece and, if necessary, attaching a housing cover.

24. The method according to claim 23, wherein the step of installing the drive unit further comprises connecting the gear unit having an eccentric, a connecting rod, a drive shaft, and a articulation piece securely connected to the drive shaft, to the electric motor by attaching the eccentric to a motor shaft of the electric motor and by attaching, preferably plugging on, the connecting rod to the eccentric and to the articulation piece securely connected to the drive shaft.

25. The method according to claim 24, wherein the step of installing the drive unit further comprises the drive shaft is locked in the gear unit zone of the first half-shell-like half and preferably further that it is mounted in a first bearing device of the gear unit zone.

26. The method according to claim 23, wherein a sealing element, preferably a bellows seal, is introduced into the key element prior to the step of installing the key element.

27. The method according to claim 23, wherein after the step of installing the key element a sealing/damping element is attached to the frame unit, wherein the sealing/damping element is slid onto the key element and preferably latches to the frame unit.

28. The method according to claim 23, wherein in the step sliding in the frame unit the insertion of the frame unit into the housing of the handpiece is supported by insertion aids, preferably by insertion ribs, which are arranged laterally on the frame unit and/or laterally on the inner wall of the housing.

29. An attachment brush for an electric toothbrush handpiece, according to claim 10, comprising: a head portion having a brush head, an attachment portion; and a neck portion connecting the head portion with the attachment portion, wherein the brush head has a brush field, wherein the brush field has at least an inner circle with a first shape of brush bundles and an outer circle with a second shape of brush bundles, wherein the first shape of brush bundles differs from the second shape of brush bundles, and wherein gaps are provided between the individual brush bundles of the first shape on the inner circle and wherein gaps are provided between the individual brush bundles of the second shape on the outer circle.

30. The attachment brush according to claim 29, wherein the first shape of brush bundles has circular segment shaped, diamond shaped, or triangular shaped brush bundles, and wherein the second shape of brush bundles has circular segment shaped, triangular shaped, or oval shaped brush bundles.

31. The attachment brush according to claim 29, wherein the brush field further has a central circle with a third shape of brush bundles, wherein gaps are provided between the individual brush bundles of the third shape on the central circle.

32. The attachment brush according to claim 31, wherein the third shape of brush bundles has circular segment-shaped, oval-shaped, or triangular-shaped brush bundles.

33. The attachment brush according to claim 31, wherein the third shape of brush bundles on the central circle corresponds to the second shape of brush bundles on the outer circle, but has a smaller dimensioning.

34. The attachment brush according to claim 31, wherein the brush bundles of the third shape on the central circle are arranged offset from the brush bundles of the second shape on the outer circle and preferably at least partially engage in the gaps between the brush bundles of the second shape on the outer circle.

35. The attachment brush according to claim 29, wherein the brush bundles of the first shape on the inner circle are arranged offset from the brush bundles of the second shape on the outer circle and preferably engage at least partially in the gaps between the brush bundles of the second shape on the outer circle.

36. The attachment brush according to claim 29, wherein the attachment portion has a coupling geometry configured to couple with a corresponding coupling geometry of an electric toothbrush handpiece.

37. An electric toothbrush comprising an electric toothbrush handpiece according to claim 10 and an attachment brush comprising: a head portion having a brush head; an attachment portion; and a neck portion connecting the head portion with the attachment portion, wherein the brush head has a brush field, wherein the brush field has at least an inner circle with a first shape of brush bundles and an outer circle with a second shape of brush bundles, wherein the first shape of brush bundles differs from the second shape of brush bundles, and wherein gaps are provided between the individual brush bundles of the first shape on the inner circle and wherein gaps are provided between the individual brush bundles of the second shape on the outer circle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0429] Further advantageous embodiments of the invention emerge from the following description of exemplary embodiments of the invention with the aid of the schematic drawing. In particular, the drive unit according to the invention, the electric toothbrush handpiece according to the invention, the manufacturing process according to the invention, the attachment brushes according to the invention, and electric toothbrushes according to the invention are described in more detail below with reference to the accompanying drawings by means of embodiment examples.

[0430] FIG. 1 shows a perspective view of an electric toothbrush or handpiece according to the invention with a mounted attachment brush according to the invention in the front view in accordance with the oscillating variant.

[0431] FIG. 2 shows a top view of the handpiece in accordance with FIG. 1.

[0432] FIG. 3 shows a side view of the handpiece in accordance with FIG. 1.

[0433] FIG. 4 shows a bottom view of the handpiece in accordance with FIG. 1.

[0434] FIG. 5 shows a longitudinal section along the line B-B in FIG. 2.

[0435] FIG. 6 shows a longitudinal section along the line A-A in FIG. 3.

[0436] FIG. 7 shows a perspective view of the interior of the handpiece from the front.

[0437] FIG. 8 shows a perspective view of the interior of the handpiece from the rear.

[0438] FIG. 9 shows a first side view of the interior of the handpiece in accordance with FIG. 7.

[0439] FIG. 10 shows a second side view of the interior of the handpiece in accordance with FIG. 7.

[0440] FIG. 11a shows a top view of the interior of the handpiece.

[0441] FIG. 11b shows a bottom view of the interior of the handpiece.

[0442] FIG. 12a shows a detailed view of the drive unit according to the invention.

[0443] FIG. 12b shows a detailed view of the rear end of the frame unit with the coil carrier attached.

[0444] FIG. 13 shows an exploded view of the interior of the handpiece from above.

[0445] FIG. 14 shows an exploded view of the interior of the handpiece from below.

[0446] FIG. 15 shows a perspective view of an eccentric from a gear unit according to the invention.

[0447] FIG. 16 shows a perspective view of a connecting rod from a gear unit according to the invention.

[0448] FIG. 17 shows a perspective view of an articulation piece with articulation cylinder from a gear unit according to the invention.

[0449] FIG. 18 shows a perspective view of an electric toothbrush or a handpiece according to the invention with a mounted attachment brush according to the invention in the front view in accordance with the sonic variant.

[0450] FIG. 19 shows a top view of the handpiece in accordance with FIG. 18.

[0451] FIG. 20 shows a side view of the handpiece in accordance with FIG. 18.

[0452] FIG. 21 shows a longitudinal section along the line B-B in FIG. 19.

[0453] FIG. 22 shows a longitudinal section along the line A-A in FIG. 20.

[0454] FIG. 23 shows a detailed view of a gear unit according to the invention.

[0455] FIG. 24 shows an exploded view of the interior of the handpiece from above.

[0456] FIG. 25 shows an exploded view of the interior of the handpiece from below.

[0457] FIG. 26 shows a perspective view of a first embodiment of a brush head according to the invention.

[0458] FIG. 27 shows a side view of the brush head in accordance with FIG. 26.

[0459] FIG. 28 shows a top view of the brush head in accordance with FIG. 26.

[0460] FIG. 29 shows a perspective view of a second embodiment of a brush head according to the invention.

[0461] FIG. 30 shows a side view of the brush head in accordance with FIG. 29.

[0462] FIG. 31 shows a top view of the brush head in accordance with FIG. 29.

[0463] FIG. 32 shows a perspective view of a third embodiment of a brush head according to the invention.

[0464] FIG. 33 shows a side view of the brush head in accordance with FIG. 32.

[0465] FIG. 34 shows a top view of the brush head in accordance with FIG. 32.

[0466] FIG. 35 shows a perspective view of a further embodiment of the interior of the handpiece from the front.

[0467] FIG. 36 shows a perspective view of a further embodiment of FIG. 35 of the interior of the handpiece from the rear.

[0468] FIG. 37 shows a side view of the interior of the handpiece in accordance with FIG. 35.

[0469] FIG. 38a shows a detailed view of the drive unit according to the invention from FIG. 35.

[0470] FIG. 38b shows a detailed view of the rear end of the frame unit of FIG. 35 with coil carrier attached.

[0471] FIG. 39 shows an exploded top view of the interior of the handpiece of FIG. 35.

[0472] FIG. 40 shows an exploded view of the interior of the handpiece of FIG. 35 from below.

[0473] FIG. 41a shows a perspective view of an eccentric from a gear unit according to the invention in another embodiment from the front.

[0474] FIG. 41b shows a perspective view from behind of an eccentric of a gear unit according to the invention in an embodiment of FIG. 40a.

[0475] FIG. 42a shows a perspective view of an eccentric from a gear unit according to the invention in yet another embodiment from the front.

[0476] FIG. 42b shows a perspective view from behind of an eccentric of a gear unit according to the invention in an embodiment of FIG. 41a.

[0477] FIG. 43 shows a sleeve for the eccentric pin according to the invention, the articulation pin according to the invention or the connecting rod according to the invention or its bearing.

DETAILED DESCRIPTION

[0478] Certain expressions are used in the following description for practical reasons and are not to be understood as limiting. The words right, left, bottom and top denote directions in the drawing to which reference is made. The terms inward, outward, below, above, left, right or similar are used to describe the arrangement of designated parts relative to one another, the movement of designated parts relative to one another and the directions toward or away from the geometric center of the invention and designated parts thereof as shown in the drawings. This spatial relative information also comprises different positions and orientations from those shown in the drawings. For example, if a part shown in the drawings is reversed, elements or features that are described as below are then above. The terminology comprises the words expressly mentioned above, their derivations and words with similar meanings.

[0479] In order to avoid repetitions in the drawings and the associated description of the different aspects and embodiments, certain features are to be understood as common for different aspects and embodiments. The omission of an aspect in the description or a drawing does not suggest that this aspect is missing in the associated embodiment. Rather, such omissions are made for the sake of clarity and to avoid repetition. In this connection, the following stipulations apply to the entire remainder of the description: If, for purposes of clarity in the drawing, a figure contains reference signs, but these are not mentioned in the text of the description relating directly thereto, reference is made to their explanation in preceding figure description. If reference signs are also mentioned in the text of the description relating directly to a figure that are not included in the corresponding figure, reference is made to the preceding and following figures. Similar reference signs in two or more drawings represent similar or identical elements.

[0480] FIGS. 1 to 17 illustrate an electric toothbrush 1 in accordance with the present invention for, in particular, the oscillating version.

[0481] The electric toothbrush 1 shown in FIG. 1 comprises an electric toothbrush handpiece 2 and an attachment brush 3 attached thereon. The electric toothbrush handpiece 1 comprises an on/off switch 5 and signal elements 4, such as LED lights. The attachment brush 3 comprises a brush head 31 with a plurality of bristle bundles 32 arranged thereon, which together form the brush field. The brush head 31 is designed round here for the oscillating variant. In the oscillating version, the brush head 31 is designed to perform a periodic back-and-forth rotary movement about the brush head axis X.sub.B (cf. double arrow). The attachment brush 3 is permanently mounted opposite the electric toothbrush handpiece.

[0482] FIGS. 2 to 4 show the associated electric toothbrush handpiece 2 without attachment brush 3 from above, from the side and from below. A key element 7 is attached to the front end of the electric toothbrush handpiece 1, which serves as an interface or coupling structure for the attachment brush 3.

[0483] In this case, the attachment brush 3 is arranged fixed relative to the handpiece 2 and fixed relative to the drive shaft 12. From its basic position shown in FIG. 3, the drive shaft 12 performs a periodic back-and-forth pivoting movement (cf. double arrow), which can be converted, if necessary, by a corresponding conversion unit in the corresponding attachment brush into the aforementioned back-and-forth rotary movement for the brush head of an oscillating attachment brush.

[0484] FIG. 5 shows a longitudinal section of the electric toothbrush handpiece 2 along the line B-B in FIG. 2. This initially comprises the housing 6 and, at its rear end, a housing cover 17 which closes off the housing 6. The housing cover 17 has an opening 18 in the form of a blind hole for inserting a ferrite core of a corresponding charging apparatus. In this respect, a charging coil 28a arranged on a coil carrier surrounds the opening 18.

[0485] The key element 7 protrudes from the front end of the housing 6, which is mounted with its rear end area inside the housing 6. A sealing/damping element 8 is slipped over the key element 7, which provides a seal between the key element 7 and the housing 6 as well as a damped bearing of the key element 7 within the housing 6. Further, this provides some damped bearing of the frame unit, of which the first half-shell-like half 20a is seen here, in the housing.

[0486] Also arranged in the front area of the housing 6 is the gear unit 11, which drives the drive shaft 12. The drive shaft 12 is supported at its rear end in a first bearing device 22 and in the area of its front end in a second bearing device 7c, which is formed by the front end of the key element 7. The relatively widely spaced bearing devices 22 and 7c can ensure particularly smooth and stable running of the drive shaft 12.

[0487] In the key element 7, i.e. in the recess 7d of the key element 7, a bellows seal 19 is arranged as a sealing arrangement, which is configured to seal the housing against the drive shaft 12. The bellows seal 19 has a rotationally symmetrical design. An annular element of the bellows seal, which is designed internally, abuts the drive shaft 12. An annular element of the bellows seal, which is designed externally, rests against the key element 7. The position of the bellows seal is secured in the longitudinal direction of the drive shaft 12 once at the front by means of a stop in the key element and once at the rear by means of a stop on the frame unit.

[0488] The electric motor 16 is arranged directly behind the gear unit 11 and drives the gear unit 11 by means of its motor shaft 16a. An eccentric 15 is attached (directly) to the motor shaft 16a. A battery 21 is arranged behind the electric motor 16, which is held clamped between a front spring plate 204 and a rear spring plate 203. In FIG. 5, the spring plates 203, 204 are shown in their unloaded positionit is visible from the illustration of the accumulator 21 by how much the spring plates 203, 204 are bent back to realize the clamping.

[0489] FIG. 6 illustrates a longitudinal section of the electric toothbrush handpiece 2 along line A-A in FIG. 3. It is possible to see substantially the same components as in FIG. 5, but here the connecting rod 14 attached to the eccentric 15 and to the articulation piece 13 of the drive shaft 12 is clearly visible.

[0490] The two views in accordance with FIGS. 7 and 8 substantially show the interior of the handpiece 2 without the housing 6, which in the present assembled form is also referred to as the slide-in unit 9. The frame unit 20 represents a kind of chassis to which all components or parts are fastened to ensure safe and targeted insertion into the housing 6 during final installation.

[0491] A print plate 27 is attached on top of the frame unit 20. This has openings through which protrude a first connecting piece 204b of the first spring plate 204 and a first connecting piece 203b of the rear spring plate 203, which are soldered to the print plate 27. This makes the electrical connection with the electrical conduits on the print plate 27. In addition, the connecting pieces 203b and 204b serve as orientation aids during the installation of the print plate 27. The print plate is preferably inserted into a recess in the frame unit and held by means of clamping arms 208. The coil carrier 28 can be seen at the rear end of the slide-in unit 9.

[0492] The battery 21 is inserted into the frame unit 20 from below, as shown in FIG. 8, and held in place by means of latching apparatuses or preload surfaces 25 and spring plates 203, 204. The electric motor 16 is also received in a form-fit/force-fit manner by the frame unit 20. Two snap elements 201 also protrude from the front of the frame unit, which engage with corresponding latching devices in the key element 7 (here concealed by the sealing/damping element 8). The sealing/damping element 8 has guide rails 8a which assist in inserting/positioning the slide-in unit 9 into the handpiece 2 and, if necessary, cooperate with corresponding rails on the inside of the housing 6.

[0493] Referring first to FIGS. 9 and 10, it is illustrated that the frame unit 20 is formed from two half-shell-like halves 20a and 20b. In this respect, in FIG. 9, the slide-in unit 9 is shown from the side and in FIG. 10, the second half-shell-like half 20b of the frame unit 20 (the first half-shell-like half 20a has been removed) is shown from the side.

[0494] The half-shell-like halves 20a, 20b of the frame unit 20 have multiple zones for the receptacle of interior components. In FIG. 9, viewed from the rear end, one can first see the coil zone 29d, the battery zone 29c, the motor zone 29b, and the gear unit zone 29a of the frame unit 20. Both half-shell-like halves of the frame unit 20 have a substantially corresponding configuration or substantially mirrored configuration.

[0495] In the coil zone 29d, the coil carrier 28 is fitted onto the frame unit 20. The coil carrier 28 comprises a length compensation means 28b, which in the installed state resiliently supports the frame unit 20 relative to the housing cover 17. The length compensation means 28b is designed in the form of an elastic portion of the coil carrier 28, on which a length compensation between the frame unit 20 and the coil carrier 28 is achieved as well as a floating bearing of the frame unit 20 within the housing 6. In particular, the length compensation means 28b can also be designed to be compressible. In addition, the coil carrier 28 comprises upper and lower snap-on means 28c, 28d (cf. also FIG. 12b) with which it (additionally) snaps onto the rear end of the frame unit 20 to ensure an even better hold on the frame unit 20.

[0496] Coil zone 29d is followed by battery zone 29c, which is empty here. In the accumulator zone 29c, a plurality of apertures 214 and connecting webs 213 are formed in the side walls of the frame unit, which together form a truss-like structure. In this way, material can be saved on the one hand, and on the other hand the lattice-like structure of the battery zone 29c also gives it advantageous flexibility properties, which are decisive approximately for the receptacle as well as the hold of the battery 21. The apertures 214 and the connecting webs 213 are preferably arranged substantially symmetrically with respect to each other.

[0497] The battery zone 29c is followed by the motor zone 29b. The motor zone 29b accommodates the electric motor 16. In addition, guide cylinders 210 and corresponding blind holes 211 are arranged in the area of the motor zone 29b, which serve in particular to position the two half-shell-like halves 20a, 20b of the frame unit 20. Furthermore, snapping apparatuses 216 and corresponding snap-in openings 217 are provided in the area of the motor zone 29b, which ensure that the two half-shell-like halves 20a, 20b are held securely after installation. The snapping apparatus 216 and the snap-in openings 217, as well as the guide cylinders 210 and the blind holes 211, are respectively arranged above and below the electric motor 16 on the frame unit 20, preferably substantially evenly distributed to provide optimum guidance and strength characteristics for the frame unit 20. Further, snapping apparatuses 216 and the snap-in openings 217 are arranged in the area of the gear unit zone 29a and the coil zone 29d. Further, guide cylinders 210 and corresponding blind holes 211 are arranged in the coil zone 29d.

[0498] The motor zone 29b is followed by the gear unit zone 29a. The eccentric 15, the connecting rod 14 and the rear part of the drive shaft 12 with the injection-molded articulation piece 13 are arranged in the gear unit zone 29a. The rear end of the drive shaft 12 is received in a first bearing device 22, which is preferably designed as a plain bearing. In the side of the articulation piece 13 facing away from the electric motor 16, a tensioning arm 23 is also provided, which presses on the drive shaft 12 to prevent the drive shaft 12 from chattering, if necessary. The gear unit zone 29a is terminated at the front by the guide pin 212 of the frame unit 20. Above the guide pin 212 is the snap element 201 for the key element 7. The sealing/damping element 8 (see FIG. 9) is regularly attached to or respectively placed over the key element 7 before it is pushed into the housing.

[0499] FIGS. 11a and 11b are substantially the same as FIGS. 7 and 8 described above. FIG. 11a once again illustrates the preferred symmetrical design of the truss structure in the accumulator zone 29c on both sides of the frame unit 20. Further, the clamping arms 208 for holding the print plate 27 are clearly visible. FIG. 11b shows the lower bump line 215 of the first half-shell-like half 20a and the second half-shell-like half 20b in the area of the motor zone 29b and the gear unit zone 29a. Further, the preload surfaces 25 for holding the battery 21 are readily apparent.

[0500] FIG. 12a shows in particular a detailed view of the drive unit 10 with the gear unit 11 and the motor 16 in accordance with the present invention. The gear unit 11 comprises the drive shaft 12 with the injection-molded articulation piece 13, the connecting rod 14 and the eccentric 15. The main part 15a of the eccentric 15 is attached to or pressed onto the motor shaft 16a of the electric motor 16 with its rear or motor end. The motor shaft 11a and the axis of the main part coincide. The main part 15a of the eccentric 15 preferably comprises two recesses 15c, of which only one can be seen here. The recesses 15c are used to generate an optimized unbalance.

[0501] On its face side, the main part 15a of the eccentric 15 comprises an offset 15e and a corresponding pedestal-like elevation 15d. This design of the end face of the eccentric main part 15a serves in particular to enable the eccentric 15 and the connecting rod 14 to be operated with as little intermediate space as possible. The offset 15e is dimensioned in such a manner that in the movement of the gear unit 11 the eccentric main part 15a just passes the lower bearing 14b of the connecting rod 14, which cannot be seen here, without touching it. The upper bearing 14a of the connecting rod 14 is fitted onto the eccentric pin 15b. The bearings 14a, 14b of the connecting rod 14 are preferably designed as plain bearings directly in the body of the connecting rod 14. The lower bearing 14b of the connecting rod 14, which is not shown, is fitted onto an articulation pin 13a of the articulation piece 13 corresponding to the eccentric pin 15b. This makes it possible to achieve a particularly compact and efficient design of the gear unit 11.

[0502] The individual parts of the gear unit 11 are merely fitted into one another with the smallest possible distances and tolerances between them. The rear end of the drive shaft 12 is supported in a first bearing device 22 of the second half-shell-like half 20b. In this case, the first bearing device 22 is preferably designed as a plain bearing and is closed off from the second half-shell-like half 20b during installation on the first half-shell-like half 20a by means of a corresponding cover 219 (cf. FIG. 9). The articulation piece 13 preferably rests on the clamping arm 23 into which the drive shaft 12 is clicked during installation and which presses on the drive shaft 12 from above in order to prevent chattering and enable particularly smooth running. The drive shaft 12 is guided out of the frame unit 20 by the guide pin 212 formed by the two half-shell-like halves 20a, 20b.

[0503] The length L.sub.G of the gear unit 11 from the rear or motor end of the eccentric main part 15a to the front end of the fixing of the articulation piece 13 to the drive shaft 12 is from 8 mm to 20 mm preferably from 11 mm to 17 mm.

[0504] FIG. 12b illustrates a detailed view of the arrangement of the coil carrier 28 at the rear end of the frame unit 20. The charging coil 28a is initially wound onto the coil carrier 28. The coil carrier 28 comprises upper snap-on means 28c and lower snap-on means 28d with which a secure hold on the frame unit 20 and the print plate 27, respectively, is achieved. The upper snap-on means 28c is designed in the form of two outwardly bent flex arms which snap onto the print plate 27, and the lower snap-on means 28d is designed in the form of a latching hook which here engages behind one of the blind holes 211 on the second half-shell-like half 20b.

[0505] The coil carrier 28 further comprises a length compensating means 28b in the form of an elastically configured portion which extends in the direction of the rear spring plate 203 but does not contact it. A web 221 of the frame unit is regularly provided between the rear spring plate 203 and the elastic portion of the coil carrier. The elastic portion or length compensation means 28b thus supports the frame unit 20 relative to the housing cover 17 (cf. FIG. 5) and provides length compensation as well as floating bearing of the frame unit 20 within the housing.

[0506] The rear spring piece 203 is inserted into a corresponding lateral receptacle of the second half-shell-like half 20b and is clamped in position by a retaining arm 218 of the second half-shell-like half 20b. The first half-shell-like half 20a has a corresponding configuration for receiving the rear spring plate 203. The installation of the front spring plate 204 behind the motor zone 29b is carried out in an analogous manner (cf. approximately FIG. 10).

[0507] FIGS. 13 and 14 once again illustrate all the essential components of the interior or of a slide-in unit 9 for an electric toothbrush handpiece 2, in each case in an exploded view from above and an exploded view from below.

[0508] FIGS. 13 and 14 (also in conjunction with the previous FIGS. 5 to 12b) clearly illustrate the installation of the slide-in unit 9 for the electric toothbrush handpiece 2.

[0509] First, the second half-shell-like half 20b of the frame unit 20 is laid out. Now the drive unit 10 is assembled with the electric motor 16 and the gear unit 11, wherein the electric motor 16 is connected to the gear unit 11 and the electric motor 16 is positioned in the motor zone 29b and the gear unit 11 is positioned in a gear unit zone 29a of the second half-shell-like half 20b and locked there. Here, the eccentric 15 is pressed onto a motor shaft 16a of the electric motor 16 and the connecting rod 14 is pushed onto the eccentric 15 or eccentric pin 15b and onto the articulation piece 13 or articulation pin 13a injection-molded onto the drive shaft 12 (see also FIGS. 15 and 17). The drive shaft 12 thereby engages with the clamping arm 23 and is supported in the first bearing device 22.

[0510] Now, the rear spring plate 203 and the front spring plate 204 are inserted from the side into corresponding receptacles of the second half-shell-like half 20b, wherein the rear and front spring plates 203, 204 are preferably each held in position by retaining arms 218.

[0511] Now the print plate 27 is mounted in the print zone 29e of the second half-shell-like half 20b, wherein in each case at least a first connecting piece 203a of the rear spring plate 203 and a first connecting piece 204a of the front spring plate 204 are guided through corresponding recesses 207 in the print plate 27, and the print plate 27 is preferably received in a (double-sided) recess 200 of the print zone 29e and locked there if necessary. Support struts 220 are provided on both sides of the upper side of the motor zone 29b to support the print plate 27 in the front area, where in particular the on/off switch 5 is arranged. In this way, the pressure exerted by a user on the on/off switch 5 can be better absorbed. The support struts 220 form a kind of bottom of the recess 200 for the print plate 27. Regularly, no support struts 220 are provided in the accumulator zone 29c. However, corresponding designs would be conceivable in principle.

[0512] Subsequently, the first half-shell-like half 20a is installed on the second half-shell-like half 20b, wherein the two half-shell-like halves of the frame unit 20 are preferably inserted and/or clicked into each other at several locations (cf. in this respect the guide cylinders 210 and the corresponding blind holes 211 as well as the snapping apparatuses 216 and the corresponding snap-in openings 217 in FIGS. 9 and 10).

[0513] Now the key element 7 is installed on the assembled frame unit 20, wherein the key element 7 is slid on over the drive shaft 12 and preferably latches with the snap elements 201 of the frame unit 20. Before this, however, a bellows seal 19 (particularly preferred for the oscillating variant) is usually inserted into the inner geometry area 7d of the key element 7. Subsequently, the sealing/damping element 8 is still mounted on the frame unit 20, wherein the sealing/damping element 8 is slid over the key element 7 and preferably snaps onto the frame unit 20 at the front.

[0514] Then, the coil carrier 28 with a charging coil 28a is mounted to the assembled frame unit 20, wherein the coil carrier 28 is plugged or snapped onto the rear end area of the frame unit 20 (cf. FIG. 12b).

[0515] Subsequently, the necessary electrical connections are usually made (not shown here), wherein wires are usually run from the print plate 27 to the electric motor 16 (or vice versa) and the first connectors 203a, 204a of the rear and front spring plates 203, 204 as well as the ends of the cables of the charging coil 28a are soldered to the print plate 27.

[0516] Finally, the battery 21 is inserted from below through an opening 222 into the battery zone 29c of the assembled frame unit 20, where it is received in a clamped manner between the spring piece 203b of the rear spring element 203 and the spring piece 204b of the front spring element 204 and, if necessary, is additionally held by the lateral preload surfaces 25.

[0517] Finally, the fully assembled frame unit 20 is inserted into the housing 6 of the handpiece 2 as a slide-in unit 9 and, if necessary, the housing cover 17 is also attached. The insertion of the frame unit 20 into the housing 6 of the handpiece 2 is regularly supported by insertion aids, preferably by insertion ribs/rails, which are arranged laterally on the frame unit 20 or on the sealing/damping element 8 and/or laterally on the inner wall of the housing 6. The sealing/damping element 8 comprises, in particular, two guide rails 8a on each side, which assist in inserting/positioning the interior of the handpiece 2 and, if necessary, cooperate with corresponding rails of the housing.

[0518] FIG. 15 now shows a single view of an eccentric 15 for the gear unit 11 of the electric toothbrush handpiece 2. The design is basically the same for the oscillating variant and the sonic variant, only the dimensioning of the individual components may differ.

[0519] The eccentric 15 comprises a cylindrical main part 15a, on whichoffset parallel to the main part axis X.sub.Ga cylindrical eccentric pin 15b with an eccentric pin axis X.sub.Z is arranged. The distance from the main part axis X.sub.G to the eccentric pin axis X.sub.Z forms the eccentricity E. The eccentricity E is between 0.2 mm and 3 mm and preferably between 0.3 mm and 2 mm. For the oscillating variant, the eccentricity E is particularly preferably between 1.4 mm and 2 mm, whereas the eccentricity for the sonic variant is particularly preferably between 0.3 mm and 1 mm.

[0520] Lateral recesses 15c are made or milled in the main part 15a of the eccentric 15. The recesses 15c are configured in such a manner, here in the form of two lateral milled recesses, that in operation the center of mass of the eccentric 15 lies on the axis of the motor shaft 16a of the electric motor 16 (which coincides with the main body axis), to which the eccentric 15 is attached. The eccentric 15 therefore has an improved design with a correspondingly optimized unbalance.

[0521] On its face side, the eccentric main part 15a also has an offset 15e and a corresponding pedestal-like elevation 15d. This ultimately allows the eccentric 15 to be arranged closer to a corresponding connecting rod of the gear unit, resulting in a particularly compact design of the gear unit. The eccentric pin 15b is arranged on the pedestal-like elevation 15d.

[0522] The main part 15a of the eccentric 15 has a length (from the pedestal-like elevation to its rear end) of from 4 mm to 9 mm preferably from 5.5 mm to 7.5 mm and a diameter (excluding the recesses) of from 3 mm to 8 mm preferably from 4.5 mm to 6.5 mm.

[0523] The eccentric pin 15b of the eccentric 15 has a length of from 1 mm to 6 mm preferably from 2 mm to 4 mm and a diameter D.sub.Z of from 1 mm to 4 mm preferably from 1.5 mm to 2.5 mm.

[0524] FIG. 16 illustrates a connecting rod 14 for the gear unit 11 of a drive for an electric toothbrush handpiece 2. The design is basically the same for the oscillating variant and the sonic variant.

[0525] The connecting rod 14 comprises two bearings 14a and 14b, which are connected by a rod element 14c. The bearings 14a and 14b each have a bearing axis X.sub.P and preferably the same (inner and outer) diameter.

[0526] The length of the connecting rod 14 (from bearing axis to bearing axis) is from 3 mm to 8 mm preferably from 4.5 mm to 6.5 mm.

[0527] The thickness of the connecting rod 14 (in the direction of the bearing axes) is from 1 mm to 5 mm preferably from 1.5 mm to 3.5 mm.

[0528] The width of the connecting rod (perpendicular to the bearing axes) is from 1.5 mm to 6.5 mm preferably from 3 mm to 5 mm.

[0529] The rod element 14c may have a slightly smaller thickness and width than the bearings 14 and 14b, resulting in a bone-like shape for the connecting rod 14.

[0530] FIG. 17 illustrates a drive shaft 12 with an injection-molded articulation piece 13 for the gear unit 11 of an electric toothbrush handpiece 2. The design is basically the same for the oscillating variant and the sonic variant.

[0531] The drive shaft 12 comprises a front end 12a and a rear end 12b. At the front end 12a, the drive shaft has a flattening 12c and a notch 12d. The flattening 12c and the indentation 12d are regularly used for connection to or fixing on a corresponding shaft portion of a conversion unit of an oscillating attachment brush 3.

[0532] The articulation piece 13 molded onto the drive shaft 12 preferably completely encloses the drive shaft 12 and has an articulation pin 13 which has a diameter D.sub.GZ which preferably corresponds to the diameter D.sub.EZ of the eccentric pin (i.e. in both the sonic and oscillating variants).

[0533] The articulation piece 13 has a length L.sub.GS (from bearing center to bearing center) of from 2 mm to 6 mm preferably from 3.5 mm to 4.5 mm.

[0534] The drive shaft 12 has a diameter D.sub.A of 1.5 mm to 4.5 mm preferably of 2.5 mm to 3.5 mm. In the area of the flattening 12c, these values can be correspondingly smaller, or the diameter is to be understood as the diameter continuation of the non-flattened parts.

[0535] FIGS. 18 to 25 illustrate an electric toothbrush 1 in accordance with the present invention for, in particular, the sonic variant.

[0536] The electric toothbrush 1 shown in FIG. 18 comprises an electric toothbrush handpiece 2 and an attachment brush 3 attached thereon. The electric toothbrush handpiece 1 comprises an on/off switch 5 and signal elements 4, such as LED lights. The attachment brush 3 comprises a brush head 31 with a plurality of bristle bundles 32 arranged thereon, which together form the brush field. The brush head 31 is substantially oval in design here. In the sonic variant, the brush head 31 is designed to perform a periodic back-and-forth swinging movement around the longitudinal axis of the attachment brush X.sub.L (cf. double arrow). Here, the entire attachment brush 3 moves, i.e., the attachment brush 3 is not mounted in a secured position relative to the electric toothbrush handpiece 2.

[0537] FIGS. 18 to 20 show the associated electric toothbrush handpiece 2 without attachment brush 3 from above, from the side and from below. No key element 7 can be seen at the front end of the electric toothbrush handpiece 2, since the sonic variant does not require a coupling structure of this type for the attachment brush 3. The attachment brush 3 is secured here by the geometry of the drive shaft 12 together with a corresponding inner geometry of the attachment brush 3. Here, too, the drive shaft 12 performs a periodic back-and-forth pivoting movement from its basic position shown in FIG. 20 (cf. double arrow), which can be transmitted directly to a corresponding (sonic) attachment brush 3.

[0538] FIG. 21 shows a longitudinal section of the electric toothbrush handpiece 2 along the line B-B in FIG. 19. This initially comprises the housing 6 and, at its rear end, a housing cover 17 which closes off the housing 6. The housing cover 17 has an opening 18 in the form of a blind hole for inserting a ferrite core of a corresponding charging apparatus. In this respect, a charging coil 28a arranged on a coil carrier surrounds the opening 18.

[0539] The front end area of the housing 6 supports the key element 7, which here has no key geometry projecting outward, as explained above. However, a sealing/damping element 8 is again slipped over the key element 7, which provides a seal between the key element 7 and the housing 6 as well as a damped bearing of the key element 7 within the housing 6. Further, the sealing/damping element 8 seals against the drive shaft 12 and provides a certain amount of damped bearing of the frame unit 20 in the housing.

[0540] Also arranged in the front area of the housing 6 is the gear unit 11, which drives the drive shaft 12. The drive shaft 12 is supported at its rear end in a first bearing device 22 and in the area of its front end in a second bearing device 7c, which is formed by the key element 7. The bearing devices 22 and 7c, which are still relatively far apart in this case, can ensure particularly smooth and stable running of the drive shaft 12.

[0541] The electric motor 16 is arranged directly behind the gear unit 11 and drives the gear unit 11 by means of its motor shaft 16a. An eccentric 15 is attached to the motor shaft 16a. A battery 21 is arranged behind the electric motor 16, which is held clamped between a front spring plate 204 and a rear spring plate 203. In FIG. 21, the spring plates 203, 204 are shown in their unloaded positionit is visible from the illustration of the accumulator 21 by how much the spring plates 203, 204 are bent back to realize the clamping.

[0542] FIG. 22 illustrates a longitudinal section on the electric toothbrush handpiece 2 along the line B-B in FIG. 2. It is possible to see substantially the same components as in FIG. 21, but here the connecting rod 14 attached to the eccentric 15 and to the articulation piece 13 of the drive shaft 12 is clearly visible.

[0543] FIG. 23 shows in particular a detailed view of the drive unit 10 with the gear unit 11 and the motor 16 in accordance with the present invention. The gear unit 11 comprises the drive shaft 12 with the injection-molded articulation piece 13, the connecting rod 14 and the eccentric 15. The main part 15a of the eccentric 15 is attached to or pressed onto the motor shaft 16a of the electric motor 16 with its rear or motor end. The motor shaft 16a and the axis of the main part coincide. The main part 15a of the eccentric 15 preferably comprises two recesses 15c, of which only one can be seen here. The recesses 15c again serve to generate an optimized unbalance and are usually somewhat smaller in the sonic variant than in the oscillating variant (where the eccentricity is also usually larger, see FIG. 12a).

[0544] The upper bearing 14a of the connecting rod 14 is fitted onto the eccentric pin 15b. The bearings 14a, 14b of the connecting rod 14 are preferably designed as plain bearings directly in the body of the connecting rod 14. The lower bearing 14b of the connecting rod 14, which is not shown, is fitted onto an articulation pin 13a of the articulation piece 13 corresponding to the eccentric pin 15b. This makes it possible to achieve a particularly compact and efficient design of the gear unit.

[0545] The individual parts of the gear unit are again merely plugged into one another with the smallest possible distances and tolerances between them. The rear end of the drive shaft 12 is supported in a first bearing device 22 of the second half-shell-like half 20b. The first bearing device 22 is preferably designed as a plain bearing and is closed by the first half-shell-like half 20a during installation on the second half-shell-like half 20b by means of a corresponding cover 219 (cf. analogously FIG. 9 of the oscillating variant). The articulation piece 13 preferably rests on the clamping arm 23 into which a drive shaft 12 is clicked during installation and which presses on the drive shaft 12 from above in order to prevent chattering and enable particularly smooth running. The drive shaft 12 is guided out of the frame unit 20 by the guide pin 212 formed by the two half-shell-like halves 20a, 20b.

[0546] The length L.sub.G of the gear unit 11 from the rear or motor end of the eccentric main part 15a to the front end of the fixing of the articulation piece 13 to the drive shaft 12 is from 8 mm to 20 mm preferably from 11 mm to 17 mm.

[0547] In FIGS. 24 and 25, all components of the inner workings or of a slide-in unit 9 for an electric toothbrush handpiece 2 are again illustrated in each case in an exploded view from above and an exploded view from below.

[0548] FIGS. 24 and 25 (also in conjunction with FIGS. 21 to 23) clearly illustrate the installation of the slide-in unit 9 for the electric toothbrush handpiece 2.

[0549] First, the second half-shell-like half 20b of the frame unit 20 is laid out. Now the drive unit 10 is assembled with the electric motor 16 and the gear unit 11, wherein the electric motor 16 is connected to the gear unit 11 and the electric motor 16 is positioned in the motor zone 29b and the gear unit 11 is positioned in a gear unit zone 29a of the second half-shell-like half 20b and locked there. Here, specifically, the eccentric 15 is pressed onto a motor shaft 16a of the electric motor 16 and the connecting rod 14 is fitted onto the eccentric 15 or eccentric pin 15b and onto the articulation piece 13 or articulation pin 13a injection-molded onto the drive shaft 12. The drive shaft 12 thereby engages with the clamping arm 23 and is supported in the first bearing device 22.

[0550] Now, the rear spring plate 203 and the front spring plate 204 are inserted from the side into corresponding receptacles of the second half-shell-like half 20b, wherein the rear and front spring plates 203, 204 are preferably each held in position by retaining arms 218.

[0551] Now the print plate 27 is mounted in the print zone 29e of the second half-shell-like half 20b, wherein in each case at least a first connecting piece 203a of the rear spring plate 203 and a first connecting piece 204a of the front spring plate 204 are guided through corresponding recesses 207 in the print plate 27, and the print plate 27 is preferably received in a (double-sided) recess 200 of the print zone 29e and locked there if necessary. Support struts 220 are provided on both sides of the upper side of the motor zone 29b to support the print plate 27 in the front area, where in particular the on/off switch 5 is arranged. In this way, the pressure exerted by a user on the on/off switch 5 can be better absorbed. The support struts 220 form a kind of bottom of the recess 200 for the print plate 27. Regularly, no support struts 220 are provided in the accumulator zone. However, corresponding designs would be conceivable.

[0552] Subsequently, the first half-shell-like half 20a is installed on the second half-shell-like half 20b, wherein the two half-shell-like halves of the frame unit 20 are preferably inserted and/or clicked into each other at several locations (cf. in this respect the guide cylinders 210 and the corresponding blind holes 211 as well as the snapping apparatuses 216 and the corresponding snap-in openings 217 in FIGS. 9 and 10).

[0553] Now the installation of the key element 7 (here shortened by the key geometry) to the assembled frame unit 20 takes place, wherein the key element 7 is pushed on over the drive shaft 12 and preferably latches with the snap elements 201 of the frame unit 20. In the sonic variant, no bellows seal 19 is regularly inserted in the key element 7 (although this is also possible in principle). Subsequently, the sealing/damping element 8 is still mounted on the frame unit 20, wherein the sealing/damping element 8 is slid over the key element 7 and preferably snaps onto the frame unit 20 at the front.

[0554] Then, the coil carrier 28 with a charging coil 28a is mounted to the assembled frame unit 20, wherein the coil carrier 28 is plugged or snapped onto the rear end area of the frame unit 20 (cf. also FIG. 12b).

[0555] Subsequently, the necessary electrical connections are usually made (not shown here), wherein wires are usually run from the print plate 27 to the electric motor 16 (or vice versa) and the first connectors 203a, 204a of the rear and front spring plates 203, 204 as well as the ends of the cables of the charging coil 28a are soldered to the print plate 27.

[0556] Finally, the battery 21 is inserted from below through an opening 222 into the battery zone 29c of the assembled frame unit 20, where it is received in a clamped manner between the spring piece 203b of the rear spring element 203 and the spring piece 204b of the front spring element 204 and, if necessary, is additionally held by the lateral preload surfaces 25.

[0557] Finally, the fully assembled frame unit 20 is inserted into the housing 6 of the handpiece 2 as a slide-in unit 9 and, if necessary, the housing cover 17 is also attached. The insertion of the insertion unit 9 into the housing 6 of the handpiece 2 is regularly supported by insertion aids, preferably by insertion ribs/rails, which are arranged laterally on the frame unit 20 or on the sealing/damping element 8 and/or laterally on the inner wall of the housing 6. The sealing/damping element 8 comprises, in particular, two guide rails 8a on each side, which assist in inserting/positioning the interior of the handpiece 2 and, if necessary, cooperate with corresponding rails of the housing.

[0558] With reference to FIGS. 26 to 34, three particularly preferred embodiments for an attachment brush 3 according to the invention, particularly for the oscillating variant, are now illustrated. However, the use of the corresponding bristle field geometries is also conceivable in connection with the sonic variant.

[0559] In the first preferred embodiment shown in FIGS. 26 to 28, the attachment brush 3 comprises a head portion 30a having a round brush head 31, an attachment portion 30c, and a neck portion 30b connecting the head portion 30a to the attachment portion 30c, wherein the brush head 31 has a brush field formed by a plurality of bristle bundles.

[0560] The brush field on the brush head 31 is formed here by three different shapes of brush bundles, namely circular segment shaped brush bundles 32a (first shape), small oval brush bundles 32c (second shape) and large oval brush bundles 32b (third shape).

[0561] The individual brush bundles are arranged on three circles K.sub.1, K.sub.2 and K.sub.3 concentric to the brush head axis X.sub.B. The dotted circles K.sub.1, K.sub.2 and K.sub.3 extend approximately through the center of the individual brush bundles 32a, 32b, 32c. The center of the circles preferably corresponds to the center of rotation of the oscillating movement.

[0562] On the inner circle K.sub.1 the circular segment-shaped brush bundles 32a of the first shape are provided here, on the middle circle K.sub.2 the large oval brush bundles 32b of the third shape and on the outer circle K.sub.3 the small oval brush bundles 32c of the second shape.

[0563] Between the individual bristle bundles 32a, 32b, 32c on each of the circles K.sub.1, K.sub.2 and K.sub.3 there remain gaps 33a, 33b, 33c which are not occupied by the corresponding bristle bundles.

[0564] However, as seen here, the large oval brush bundles 32b of the third shape may be arranged on the central circle K.sub.2 in an offset manner with respect to the small oval brush bundles of the second shape 32c on the outer circle K.sub.3. In any case, the large oval brush bundles 32b of the third shape on the middle circle K.sub.2 partially engage in the gaps 33c between the small oval brush bundles of the second shape 32c on the outer circle K.sub.3.

[0565] The large oval brush bundles 32b of the third shape on the central circle K.sub.2 and the small oval brush bundles 32c of the second shape on the outer circle K.sub.3 have a bevel S in the direction of the brush head axis X.sub.B, wherein the difference between the highest and the lowest point is from 1 mm to 4 mm preferably from 2 mm to 3 mm. It is also conceivable that only the large oval brush bundles 32b of the third shape or only the small oval brush bundles 32c of the second shape have a corresponding bevel S.

[0566] The inner circle K.sub.1 here comprises, by way of example, two identical circular segment-shaped brush bundles 32a (the preferred number is between 1 and 8, even more preferably between 2 and 5), which regularly have a uniform, constant height. The circular segment-shaped brush bundles 32a on the inner circle are separated here accordingly by two gaps 33a.

[0567] The length of the individual circle segments depends on the number of brush bundles 32a used in each case and the gaps between them. The width of the individual circular segment-shaped brush bundles 32a is from 0.2 mm to 1 mm preferably from 0.3 mm to 0.6 mm. The height of the individual circular segment-shaped brush bundles 32a is from 4 mm to 8 mm preferably from 5.5 to 6.5 mm (i.e. measured from the bristle exit surface 31a).

[0568] The surface of the circular segment-shaped brush bundles 32a is from 2 mm.sup.2 to 4.5 mm.sup.2 preferably from 2.3 mm.sup.2 to 3 mm.sup.2 (i.e. in accordance with the plan view shown in FIG. 28).

[0569] The length of the gaps 33a between the individual circular segment bristle bundles 32a along the circle K.sub.1 is from 0.5 mm to 1.4 mm preferably from 0.7 mm to 1.1 mm.

[0570] The central circle K2 here comprises, by way of example, seven identical brush bundles in the form 32b of large ovals (the preferred number is between 4 and 11 even more preferably between 6 and 9). The centers of the large ovals are approximately on the circle K2. The large oval brush bundles 32b regularly have a sloping bevel S in the direction of the brush head axis XB.

[0571] The length of the large oval brush bundles 32b is from 3 mm to 6 mm preferably from 4 mm to 5 mm.

[0572] The width of the large oval brush bundles 32b is from 0.8 mm to 2.4 mm preferably from 1.2 mm to 1.8 mm.

[0573] The outer height H of the large oval brush bundles 32b (i.e. away from the brush head axis X.sub.B) is from 7 mm to 10 mm preferably from 8 mm to 9 mm. The inner height (i.e., toward the brush head axis X.sub.B) of the large oval brush bundles 32b is from 5.5 mm to 8.5 mm preferably from 6.5 mm to 7.5 mm.

[0574] The surface of the large oval brush bundles 32b is from 3 mm.sup.2 to 14 mm.sup.2 preferably from 4.5 mm.sup.2 to 7 mm.sup.2 (i.e. in accordance with the plan view shown in FIG. 28).

[0575] The brush bundles 32a, 32b of the middle and outer circles K.sub.1, K.sub.2 alternate here in circumferential direction.

[0576] The ratio of the surface area of the small oval brush bundles 32c to the surface area of the large oval brush bundles 32b is from 1:7 to 5:7 preferably from 2:7 to 1:2.

[0577] The outer circle K.sub.3 here comprises, by way of example, seven identical brush bundles 32c in the form of small ovals (the preferred number is between 4 and 11, even more preferably between 6 and 7). The centers of the small ovals are approximately on the circle K.sub.3. The small oval brush bundles 32c regularly have a sloping bevel S in the direction of the brush head axis X.sub.B.

[0578] The length of the small oval brush bundles 32c is from 2 mm to 3.5 mm preferably from 2.5 mm to 3 mm.

[0579] The width of the small oval brush bundles 32c is 0.5 mm to 2 mm preferably from 1 mm to 1.5 mm.

[0580] The outer height of the small oval brush bundles 32c (i.e. away from the brush head axis X.sub.B) is from 5.5 mm to 8.5 mm preferably from 6.5 mm to 7.5 mm. The inner height of the small oval brush bundles 32c (i.e. towards the brush head axis X.sub.B) is from 4.5 mm to 7.5 mm preferably from 5.5 mm to 6.7 mm.

[0581] The surface of the small oval brush bundles 32c is from 2 mm.sup.2 to 7 mm.sup.2 preferably from 3 mm.sup.2 to 4.5 mm.sup.2 (i.e. in plan view in accordance with FIG. 28).

[0582] In the second preferred embodiment shown in FIGS. 29 to 31, the attachment brush 3 again comprises a head portion 30a having a brush head 31, with an attachment portion 30c, and with a neck portion 30b connecting the head portion 30a to the attachment portion 30c, wherein the brush head 31 has a brush field formed by a plurality of bristle bundles.

[0583] The brush field on the brush head 31 is formed here by two different shapes of bristle bundles, namely diamond-shaped bristle bundles 32a (first shape) and triangular-shaped bristle bundles 32c (second shape).

[0584] The individual brush bundles are arranged on two circles K.sub.1 and K.sub.3 concentric to the brush head axis X.sub.B. The dotted circles K.sub.1 and K.sub.3 extend approximately through the center of the individual brush bundles 32a, 32c.

[0585] The diamond-shaped brush bundles 32a of the first shape are provided here on the inner circle K.sub.1, and the triangular-shaped brush bundles 32c of the second shape are provided on the outer circle K.sub.3.

[0586] Between the individual bristle bundles 32a and 32c on each of the circles K.sub.1 and K.sub.3, gaps 33a and 33c remain which are not occupied by the corresponding bristle bundles.

[0587] However, as seen here, the diamond-shaped brush bundles 32a of the first shape may be arranged on the inner circle K.sub.1 offset from the triangular-shaped brush bundles of the second shape 32c on the outer circle K.sub.3. In this case, the diamond-shaped brush bundles 32a of the first shape on the inner circle K.sub.1 at least partially engage in the gaps 33c between the triangular-shaped brush bundles 32c of the second shape on the outer circle K.sub.3.

[0588] The diamond-shaped brush bundles 32a of the first shape on the inner circle K.sub.1 and the triangular-shaped brush bundles 32c of the third shape on the outer circle K.sub.3 have a bevel S in the direction of the brush head axis X.sub.B. It is also conceivable that only the diamond-shaped brush bundles 32a of the first shape or only the triangular-shaped brush bundles 32c of the second shape have a corresponding bevel S.

[0589] In the present example, the inner circle K.sub.1 comprises six identical diamond-shaped brush bundles 32a (the preferred number is between 3 and 12, even more preferably between 5 and 8), in particular with a roof-shaped end face, wherein preferably the diamond axis forms the ridge. The diamond-shaped brush bundles 32a have a tip directed towards the brush head axis X.sub.B.

[0590] The length of the individual diamond-shaped brush bundles 32a is from 3 mm to 6 mm preferably from 4 mm to 5 mm.

[0591] The width of the individual diamond-shaped brush bundles 32a is from 0.7 mm to 2.5 mm, preferably from 1.2 mm to 2 mm.

[0592] The height of the individual diamond-shaped brush bundles 32a at the corners (the inside corners and the outside corners are preferably arranged at the same height) is from 5 mm to 8 mm preferably from 6 mm to 7 mm (measured from the bristle exit surface 31a).

[0593] The height of the individual diamond-shaped brush bundles 32a at the ridge is from 7 mm to 9 mm preferably from 7.5 mm to 8 mm (measured from the bristle exit surface 31a).

[0594] The surface of the individual diamond-shaped brush bundles 32a is from 2 mm.sup.2 to 7 mm.sup.2 preferably from 5 mm.sup.2 to 7 mm.sup.2 (i.e. in plan view in accordance with FIG. 31).

[0595] The number of diamond-shaped brush bundles 32a is six in this example.

[0596] The brush bundles 32a and 32c of the inner and outer circles K.sub.1 and K.sub.3 alternate here in circumferential direction.

[0597] The outer circle K.sub.3 here comprises, by way of example, six identical brush bundles 32c in the form of triangles (the preferred number is between 3 and 12, even more preferably between 5 and 8). One tip of each triangle is directed toward the brush head axis X.sub.B.

[0598] The triangular-shaped brush bundles 32c have a bevel S in the direction of the brush head axis X.sub.B. The triangular-shaped brush bundles 32c are preferably smaller than the diamond-shaped brush bundles 32a of the inner circle.

[0599] The side length of the triangle base is from 1.5 mm to 4 mm preferably from 2.2 mm to 3.2 mm.

[0600] The side length of the triangular legs (i.e. the two sides facing the brush head axis X.sub.B) is in each case from 2 mm to 4 mm preferably from 2.5 mm to 3.5 mm.

[0601] The outer height of the triangular brush bundles is from 6.5 mm to 9.5 mm preferably from 7.5 mm to 8.5 mm (measured from the bristle exit surface 31a).

[0602] The inner height of the triangular brush bundles is from 5 mm to 8 mm preferably from 6 mm to 7 mm (measured from the bristle exit surface 31a).

[0603] The surface of the triangular brush bundles 32c is from 1 mm.sup.2 to 5.5 mm.sup.2 preferably from 3 mm.sup.2 to 4.5 mm.sup.2 (i.e. in the plan view in accordance with FIG. 31)

[0604] The number of triangular brush bundles 32c is six in this example. The number of triangular brush bundles 32c of the outer circle K.sub.3 is regularly preferably equal to the number of diamond-shaped brush bundles 32a of the inner circle K.sub.1, since the brush bundles are preferably arranged alternately.

[0605] The ratio of the surface of the diamond-shaped brush bundles 32a to the surface of the triangular-shaped brush bundles 32c is from 1:5 to 5:7 preferably from 1:3 to 4:7.

[0606] In the third preferred embodiment shown in FIGS. 32 to 34, the attachment brush 3 again comprises a head portion 30a having a brush head 31, an attachment portion 30c, and a neck portion 30b connecting the head portion 30a to the attachment portion 30c, wherein the brush head 31 has a brush field formed by a plurality of brush bundles.

[0607] The brush field on the brush head 31 is formed here by three shapes of different bristle bundles, namely triangular shaped bristle bundles 32a (first shape), first circular segment shaped bristle bundles 32c (second shape) and second circular segment shaped bristle bundles 32b (third shape).

[0608] The individual brush bundles are arranged on three circles K.sub.1, K.sub.2 and K.sub.3 concentric to the brush head axis X.sub.B. The dotted circles K.sub.1, K.sub.2 and K.sub.3 extend approximately through the center of the individual brush bundles 32a, 32b, 32c.

[0609] The triangular brush bundles 32a of the first shape are provided here on the inner circle K.sub.1, the first circular-segment-shaped brush bundles 32b of the third shape are provided on the middle circle K.sub.2, and the second circular-segment-shaped brush bundles 32c of the second shape are provided on the outer circle K.sub.3.

[0610] Between the individual bristle bundles 32a, 32b, 32c on each of the circles K.sub.1, K.sub.2 and K.sub.3 there remain gaps 33a, 33b, 33c which are not occupied by the bristle bundles.

[0611] The inner circle K.sub.1 here comprises identical triangular brush bundles 32a with preferably uniform, constant height. The four triangular brush bundles 32a shown here as examples (the preferred number is between 1 and 8, even more preferably between 3 and 5) regularly form a substantially square structure with gaps 33a between them (wherein the corresponding gaps 33a form approximately a cross shape).

[0612] The side length of the triangle base is from 1.5 mm to 3.5 mm preferably from 1.7 mm to 2.7 mm.

[0613] The side length of the triangular legs (i.e. the two sides facing in the direction of the brush head axis X.sub.B) is in each case from 0.8 mm to 2.5 mm preferably from 1.2 mm to 2 mm.

[0614] The surface of the triangular brush bundles 32a is from 1 mm.sup.2 to 4 mm.sup.2 preferably from 2 mm.sup.2 to 3 mm.sup.2 (i.e. in the plan view in accordance with FIG. 34).

[0615] The length of the gaps 33a between the triangular bristle bundles 32a ranges from 0.5 mm to 1.5 mm.

[0616] The center circle K.sub.2 here preferably comprises identical brush bundles 32b with preferably uniform, constant height in the form of first circle segments which form an interrupted circular ring. This comprises, by way of example here, six first circular-segment brush bundles 32b (the preferred number being between 2 and 12, and even more preferably between 4 and 8). The first circle-segment-shaped brush bundles 32b are smaller than the second circle-segment-shaped brush bundles 32c of the outer circle K.sub.3.

[0617] The width of the first circular segment brush bundles 32b is from 0.3 mm to 1.5 mm preferably from 0.5 mm to 1 mm.

[0618] The surface area of the first circular segment brush bundles 32b is from 1.5 mm.sup.2 to 5 mm.sup.2 preferably from 2 mm.sup.2 to 3.5 mm.sup.2 (i.e. in plan view in accordance with FIG. 34).

[0619] The radius of the first circular segment shaped brush bundle 32b is from 5.5 mm to 8.5 mm preferably from 6.5 mm to 7.5 mm (starting from the brush head axis X.sub.B).

[0620] The length of the gap 33b between the first circular segment bristle bundles 32b is from 0.8 mm to 2 mm preferably from 1 mm to 1.5 mm.

[0621] The outer circle K.sub.3 here preferably comprises identical brush bundles of uniform, constant height, in the form of second circle segments which form an interrupted circular ring. This comprises, by way of example here, eight first circular-segment brush bundles 32b (the preferred number being between 2 and 12, and even more preferably between 6 and 10). The second circle-segment-shaped brush bundles 32c are larger than the first circle-segment-shaped brush bundles 32b of the middle circle K.sub.2.

[0622] The width of the second circular segment brush bundles 32c is from 0.3 mm to 1.5 mm preferably from 0.5 mm to 1 mm (i.e., preferably the same dimensions as the first circular segment brush bundles 32b).

[0623] The surface area of the second circular segment brush bundles 32c is from 2 mm.sup.2 to 7 mm.sup.2 preferably from 2.5 mm.sup.2 to 4 mm.sup.2 (i.e. in plan view in accordance with FIG. 34).

[0624] The diameter (through the center of the brush head) is from 8 mm to 14 mm preferably from 10 mm to 12 mm (starting from the brush head axis X.sub.B).

[0625] The length of the gap 33c between the second circular segment bristle bundles 32c is from 0.8 mm to 2.4 mm preferably from 1.2 mm to 2 mm.

[0626] The ratio of the surface area of the first circular segment brush bundles 32b to the surface area of the second circular segment brush bundles 32c is from 1:5 to 4.5:5 preferably from 2:5 to 4:5.

[0627] The two views in accordance with FIGS. 35 and 36 show an alternative embodiment analogous to FIGS. 7 and 8. Substantially the interior of the handpiece 2 is shown without the housing 6, which in the present assembled form is also referred to as the slide-in unit 9. The frame unit 20 represents a kind of chassis to which all components or parts are fastened to ensure safe and targeted insertion into the housing 6 during final installation.

[0628] A print plate 27 is attached on top of the frame unit 20. This has openings through which protrude a first connecting piece 204a of the first spring plate 204 and a first connecting piece 203a of the rear spring plate 203, which are soldered to the print plate 27. This makes the electrical connection with the electrical conduits on the print plate 27. In addition, the connecting pieces 203a and 204a serve as orientation aids during the installation of the print plate 27. The print plate 27 is preferably inserted into a recess in the frame unit 20 and held by means of clamping arms 208. The coil carrier 28 can be seen at the rear end of the slide-in unit 9. Complementing the recess is a combination of a lug 223 on the frame unit with a recess 224 on the print plate 27. The lug 223 of the frame unit engages in the recess 224 on the print plate 27. This allows the print plate 27 to be aligned (i.e., in terms of unambiguous installation) and can prevent longitudinal displacement.

[0629] The battery 21 is inserted into the frame unit 20 from below, as shown in FIG. 36, and held in place by means of latching apparatuses or preload surfaces 25 and spring plates 203, 204. Supportively, retaining ribs 225 are provided laterally adjacent to the preload surfaces 25 on the frame unit, at the edge of the opening of the frame unit, to also hold or assist in holding the battery or accumulator. The electric motor 16 is also received in a form-fit/force-fit manner by the frame unit 20. Two snap elements 201 also protrude from the front of the frame unit, which engage with corresponding latching devices in the key element 7 (here concealed by the sealing/damping element 8). The sealing/damping element 8 has guide rails 8a which assist in inserting/positioning the slide-in unit 9 into the handpiece 2 and, if necessary, cooperate with corresponding rails on the inside of the housing 6.

[0630] FIG. 37 shows various details which differ from those in FIGS. 9 and 10.

[0631] In the coil zone 29d, the coil carrier 28 is fitted onto the frame unit 20. The coil carrier 28 comprises a length compensation means 28b, which in the installed state resiliently supports the frame unit 20 relative to the housing cover 17. The length compensation means 28b is designed in the form of an elastic portion of the coil carrier 28, on which a length compensation between frame unit 20 and coil carrier 28 is achieved as well as a floating bearing of the frame unit 20 within the housing 6. In particular, the length compensation means 28b can also be designed to be compressible. In addition, the coil carrier 28 comprises upper snap-on means 28c and lateral snap-on means 28e (cf. also FIG. 38b), with which it (additionally) snaps onto the rear end of the frame unit 20, thus ensuring an even better hold on the frame unit 20.

[0632] The length compensation means 28b is configured as a resilient bridge, with a bridge element on the left and a bridge element on the right. The two bridge elements can each spring individually and are thus not directly coupled as if they would influence each other. This optimizes the individual adaptation to the housing with the length compensation.

[0633] Further, the retaining ribs 225 are clearly visible in the illustration, which are arranged to the side of the preload surface 25. They support the holding of the accumulator or battery.

[0634] FIG. 38a shows in particular a detailed view of the drive unit 10 with the gear unit 11 and the motor 16 in accordance with the present invention. The gear unit 11 comprises the drive shaft 12 with the injection-molded articulation piece 13, the connecting rod 14 and the eccentric 15. The main part 15a of the eccentric 15 is attached to or pressed onto the motor shaft 16a of the electric motor 16 with its rear or motor end. The motor shaft 16a and the axis of the main part coincide. The main part 15a of the eccentric 15 preferably comprises two recesses 15c, of which only one can be seen here. The recesses 15c are used to generate an optimized unbalance.

[0635] On its face side, the main part 15a of the eccentric 15 comprises an offset 15e and a corresponding pedestal-like elevation 15d. This design of the end face of the eccentric main part 15a serves in particular to enable the eccentric 15 and the connecting rod 14 to be operated with as little intermediate space as possible. The offset 15e is dimensioned in such a manner that in the movement of the gear unit 11 the eccentric main part 15a just passes the lower bearing 14b of the connecting rod 14, which cannot be seen here, without touching it. The upper bearing 14a of the connecting rod 14 is fitted onto the eccentric pin 15b. The bearings 14a, 14b of the connecting rod 14 are preferably designed as plain bearings directly in the body of the connecting rod 14. The lower bearing 14b of the connecting rod 14, which is not shown, is fitted onto an articulation pin 13a of the articulation piece 13 corresponding to the eccentric pin 15b. This makes it possible to achieve a particularly compact and efficient design of the gear unit 11.

[0636] The individual parts of the gear unit 11 are merely fitted into one another with the smallest possible distances and tolerances between them. The rear end of the drive shaft 12 is supported in a first bearing device 22 of the second half-shell-like half 20b. In this case, the first bearing device 22 is preferably designed as a plain bearing and is closed off from the second half-shell-like half 20b during installation on the first half-shell-like half 20a by means of a corresponding cover 219 (cf. FIG. 9). The bearing device 22 may be designed to be reinforced to better absorb forces impacting the drive shaft 12. The reinforcement can happen, for example, with a reinforcement rib 22a on the upper side of the bearing device 22. The articulation piece 13 preferably rests on the clamping arm 23 into which the drive shaft 12 is clicked during installation and which presses on the drive shaft 12 from above in order to prevent chattering and enable particularly smooth running. The drive shaft 12 is guided out of the frame unit 20 by the guide pin 212 formed by the two half-shell-like halves 20a, 20b.

[0637] FIG. 38b illustrates a detailed view of the arrangement of the coil carrier 28 at the rear end of the frame unit 20. The charging coil 28a (not shown) is initially wound onto the coil carrier 28. The coil carrier 28 comprises upper snap-on means 28c and lateral snap-on means 28e with which a secure hold on the frame unit 20 or the print plate 27 is achieved. The upper snap-on means 28c are designed in the form of two outwardly bent flex arms which snap onto the print plate 27, and the lateral snap-on means 28e in the form of two snap-in hooks per side which snap into corresponding recesses on the frame unit.

[0638] The coil carrier 28 further comprises a length compensating means 28b in the form of a resiliently configured portion in the form of a resilient bridge (left and right), which extends in the direction of the rear spring plate 203 but does not contact it. The elastic portion or length compensation means 28b thus supports the frame unit 20 relative to the housing cover 17, providing length compensation and a floating bearing for the frame unit 20 within the housing.

[0639] The rear spring piece 203 is inserted into a corresponding lateral receptacle of the second half-shell-like half 20b and is clamped in position by a retaining arm 218 of the second half-shell-like half 20b. The first half-shell-like half 20a has a corresponding configuration for receiving the rear spring plate 203. The installation of the front spring plate 204 behind the motor zone 29b is carried out in an analogous manner.

[0640] FIGS. 39 and 40 once again illustrate all the essential components of the interior or of a slide-in unit 9 for an electric toothbrush handpiece 2, in each case in an exploded view from above and an exploded view from below.

[0641] FIGS. 39 and 40 clearly illustrate the installation of the slide-in unit 9 for the electric toothbrush handpiece 2. In FIG. 39, the lug 223 on the frame unit and the corresponding recess 224 on the print plate 27 (see FIG. 35) can be seen once again. Furthermore, reference is made to the description of FIGS. 13 and 14.

[0642] In FIGS. 41a and 41b, a variant of an eccentric 15 for the gear unit 11 of the electric toothbrush handpiece 2 for the oscillating variant is shown in individual view.

[0643] The eccentric 15 comprises a cylindrical main part 15a, on whichoffset parallel to the main part axis XGa cylindrical eccentric pin 15b with an eccentric pin axis XZ is arranged. The distance from the main part axis XG to the eccentric pin axis XZ forms the eccentricity E. The eccentricity E is between 0.2 mm and 3 mm and preferably between 0.3 mm and 2 mm. The connection between the main part 15a and the eccentric pin 15b occurs via a connecting surface 15h. In this case, the eccentric pin 15b is mounted on a pedestal-like elevation 15d on the connecting surface 15h. This ultimately allows the eccentric 15 to be arranged closer to a corresponding connecting rod of the gear unit, resulting in a particularly compact design of the gear unit. The eccentric pin 15b is arranged entirely on the pedestal-like elevation 15d.

[0644] The receiving opening 15g for the motor shaft is made in the rear side 15f of the eccentric 15. The main part axis XG may, but need not, coincide with the center axis of the main part 15a. The eccentric 15 rotates around the main part axis XG.

[0645] The structure of the eccentric 15 is designed in such a way that it has an improved structure with respect to the center of mass of the eccentric 15 due to the optimized volume of the body and thus also brings an optimized unbalance.

[0646] The main part 15a of the eccentric 15 has a length (from the pedestal-like elevation 15d to its rear end or rear face 15f) of from 4 mm to 9 mm preferably from 5.5 mm to 7.5 mm and a diameter of from 3 mm to 8 mm preferably from 3.5 mm to 5.5 mm.

[0647] The eccentric pin 15b of the eccentric 15 has a length of from 1 mm to 6 mm preferably from 2 mm to 4 mm and a diameter DEZ of from 1 mm to 4 mm preferably from 1.5 mm to 2.5 mm.

[0648] In FIGS. 42a and 42b, a variant of an eccentric 15 for the gear unit 11 of the electric toothbrush handpiece 2 for the sonic variant is shown in individual view.

[0649] The eccentric 15 comprises a cylindrical main part 15a, on whichoffset parallel to the main part axis X.sub.Ga cylindrical eccentric pin 15b with an eccentric pin axis X.sub.Z is arranged. The distance from the main part axis X.sub.G to the eccentric pin axis X.sub.Z forms the eccentricity E. The eccentricity E is between 0.2 mm and 3 mm and preferably between 0.3 mm and 2 mm.

[0650] The main part 15a of the eccentric 15 has a length of from 3 mm to 7 mm preferably from 3.5 mm to 5.5 mm and a diameter of from 3 mm to 8 mm preferably from 3.5 mm to 5.5 mm.

[0651] The eccentric pin 15b of the eccentric 15 has a length of from 1 mm to 6 mm preferably from 2 mm to 4 mm and a diameter D.sub.EZ of from 1 mm to 4 mm preferably from 1.5 mm to 2.5 mm.

[0652] The receiving opening 15g for the motor shaft is made in the rear side 15f of the eccentric 15. The main part axis XG may, but need not, coincide with the center axis of the main part 15a. The eccentric 15 rotates around the main part axis XG.

[0653] Finally, FIG. 43 shows an example of a sleeve 226 as it can be provided for the eccentric pin 15b, the articulation pin 13a and/or the connecting rod 14 or its bearings 14a, 14b (i.e. in particular if the latter are made of plastic) or can be fitted or inserted on the latter. The sleeve 226 is preferably designed in the form of a bearing or plain bearing sleeve, which improves the sliding properties of the moving parts of the gear unit. The sleeve 226 is preferably formed of metal, particularly brass. The sleeve 226 may further be open at both ends (i.e., approximately in the form of a tubular member) or closed at one end (i.e., approximately in the form of a thimble). The sleeve 226 preferably has a substantially cylindrical sidewall 226a.

[0654] Although the invention is illustrated and described in detail by means of the figures and the accompanying description, such illustration and detailed description are to be understood as illustrative and exemplary and do not limit the invention. In order not to obscure the invention, well-known structures and techniques may not be shown and described in detail in certain cases. It is understood that a person skilled in the art can make changes and modifications without departing from the scope of the following claims. In particular, the present invention covers further exemplary embodiments with any combinations of features that may deviate from the explicitly described feature combinations.

[0655] The present disclosure also includes embodiments having any combination of features that are mentioned or shown above or below with respect to various embodiments. It also includes individual features in the figures, even if they are shown there in connection with other features and/or are not mentioned above or below. Alternatives of embodiments described in the figures and the description and individual alternatives of their features can also be excluded from the subject matter of the invention or from the disclosed subject matter. The disclosure includes embodiments comprising exclusively the features described in the claims or in the exemplary embodiments and those comprising additional features.

[0656] Furthermore, the expression comprise and derivations thereof do not exclude other elements or steps. Likewise, the indefinite article a or an and derivations thereof do not exclude a plurality. The functions of several features listed in the claims can be performed by one unit or one step. The mere fact that certain measures are listed in different dependent claims does not mean that a combination of those measures cannot be used advantageously. The terms substantially, approximately, about and the like, when used in conjunction with a property or value, in particular also define precisely that property or that value. The terms approximately and about, when used in connection with a given numerical value or range, can refer to a value or range that is within 20%, within 10%, within 5% or within 2% of the given value or range. All reference signs in the claims are not to be understood as limiting the scope of the claims.

LIST OF REFERENCE SIGNS

[0657] 1 electric toothbrush [0658] 2 electric toothbrush handpiece (handpiece) [0659] 3 attachment brush [0660] 4 signal elements [0661] 5 on/off switch [0662] 6 housing [0663] 7 key element [0664] 7a key geometry [0665] 7b recess [0666] 7c second bearing device [0667] 7d interior geometry [0668] 8 sealing/damping element [0669] 8a guide rails [0670] 9 slide-in unit [0671] 10 drive unit [0672] 11 gear unit [0673] 12 drive shaft [0674] 12a front end drive shaft [0675] 12b rear end drive shaft [0676] 12c flattening [0677] 12d notch [0678] 13 articulation piece [0679] 13a articulation pin [0680] 14 connecting rod [0681] 14a first bearing [0682] 14b second bearing [0683] 14c rod element [0684] 15 eccentric [0685] 15a main part [0686] 15b eccentric pin [0687] 15c recesses [0688] 15d pedestal-like elevation [0689] 15e offset [0690] 15f rear side [0691] 15g receiving opening [0692] 15h connecting surface [0693] 16 electric motor [0694] 16a motor shaft [0695] 17 housing cover [0696] 18 opening [0697] 19 bellows seal [0698] 20 frame unit [0699] 20a first half-shell-like half [0700] 20b second half-shell-like half [0701] 21 energy source (battery) [0702] 22 first storage device [0703] 22a reinforcement rib [0704] 23 clamping arm [0705] 24 latching device (motor) [0706] 25 preload surfaces (battery zone) [0707] 26 holding device (coil) [0708] 27 print plate [0709] 28 coil carrier [0710] 28a charging coil [0711] 28b length compensation means [0712] 28c snap-on means (top) [0713] 28d snap-on means (bottom) [0714] 28e snap-on means (side) [0715] 29a gear unit zone [0716] 29b motor zone [0717] 29c energy source zone (battery zone) [0718] 29d coil zone [0719] 29e print zone [0720] 200 recess for print plate [0721] 201 snap element (front) [0722] 203 rear spring plate [0723] 203a first connecting piece [0724] 203b spring piece [0725] 204 front spring plate [0726] 204a first connecting piece [0727] 204b spring piece [0728] 207 recesses print plate [0729] 208 clamping arms for print plate [0730] 210 guide cylinder frame (positioning aids) [0731] 211 blind holes (positioning aids) [0732] 212 guide pin (front frame) [0733] 213 connecting webs [0734] 214 apertures [0735] 215 bump line (bottom) [0736] 216 snapping apparatuses [0737] 217 snap-in openings [0738] 218 retaining arms (spring plates) [0739] 219 cover [0740] 220 support struts [0741] 221 web [0742] 222 opening battery [0743] 223 lug (frame) [0744] 224 recess (print plate) [0745] 225 holding ribs [0746] 226 sleeve [0747] 226a side wall sleeve [0748] 30a head portion [0749] 30b neck portion [0750] 30c attachment portion [0751] 31 brush head [0752] 31a exit surface brushes [0753] 32 brush bundle (general) [0754] 32a brush bundle (first shape) [0755] 32b brush bundle (third shape) [0756] 32c brush bundle (second shape) [0757] 33a gaps [0758] 33b gaps [0759] 33c gaps [0760] D.sub.A diameter drive shaft [0761] D.sub.EZ diameter eccentric pin [0762] D.sub.GZ diameter articulation pin [0763] E eccentricity [0764] H height brush bundle (outside) [0765] K.sub.1 inner circle [0766] K.sub.2 center circle [0767] K.sub.3 outer circle [0768] L.sub.G gear unit length [0769] L.sub.GS articulation piece length [0770] S bevel [0771] X.sub.B brush head axis [0772] X.sub.G main part axis [0773] X.sub.L longitudinal axis attachment brush [0774] X.sub.Z eccentric pin axis [0775] X.sub.P bearing axle connecting rod