Toothbrush

Abstract

A toothbrush has a brush head, at least one folded bristle bundle and at least one plastic anchor plate, wherein the brush head has a hole with a longitudinal axis for the at least one bristle bundle, wherein an anchor plate is fixed in the hole to anchor the respective bristle bundle, the anchor plate being held in two grooves running parallel to the longitudinal axis, which are formed in the hole by injection molding, the grooves having a centering section which, when viewed in a direction perpendicular to the longitudinal axis, has a depth that successively decreases with increasing distance from an entrance of the hole.

Claims

1. A toothbrush comprising: a plastic brush head, at least one folded bristle bundle, and at least one plastic anchor plate, the brush head having a hole for one of the at least one folded bristle bundle, with a longitudinal axis and a hole cross-section with a basic shape for receiving the one of the at least one folded bristle bundle, and an anchor plate fixed in the hole for the purpose of anchoring a respective on of the at least one bristle bundle, wherein a wall of the hole comprises two grooves running parallel to the longitudinal axis and extending beyond the basic shape of the hole cross-section injection molded in the wall of the hole, wherein the anchor plate is fixed in the two grooves in the U-shaped profile by a weld, and the two grooves have, adjacent to an entrance of the hole, a combination section with centering and tapering section, which, when viewed in a direction perpendicular to the longitudinal axis has a depth and a width which successively decrease with increasing distance from an entrance to the hole.

2. The toothbrush according to claim 1, wherein the two grooves each have a constant section which, when viewed in the direction observed in the direction perpendicular to the longitudinal axis has a width and a depth which are each constant along the longitudinal axis.

3. The toothbrush according to claim 1, wherein the depth of the combination section with centering and tapering section decreases in two stages.

4. The toothbrush according to claim 1, wherein the width of the combination section with centering and tapering section decreases in two stages.

5. The toothbrush according to claim 1, wherein the width of the constant section is greater than a thickness of the anchor plate.

6. The toothbrush according to claim 1, wherein an anchoring direction formed by the opposing two grooves is at an angle greater than zero to a hole line direction of directly neighboring holes.

7. A method for manufacturing a toothbrush with a brush head made of plastic and with at least one bristle bundle anchored in the brush head, comprising the following steps: a) providing a brush head with a hole for fixing the at least one bristle bundle with a longitudinal axis and a hole cross-section with a basic shape for receiving one of the a least one folded bristle bundle, wherein in a wall of the hole two grooves running parallel to the longitudinal axis and extending beyond the basic shape of the hole cross-section are formed by injection molding, the two grooves having, adjoining an entrance to the hole, have a combination section with centering and tapering sections, which, when viewed in a direction perpendicular to the longitudinal axis, has a depth and a width that successively decrease with increasing distance from an entrance of the hole. b) providing a plastic anchor plate for anchoring a respective one of the at least one folded bristle bundle in the hole, and c) inserting the anchor plate with the one of the at least one folded bristle bundle into the hole, whereby the anchor plate is inserted into the combination section of the grooves and fixed in the u-profile using a friction welding process.

8. A method according to claim 7, wherein the two grooves each have a constant section which, when viewed in the direction perpendicular to the longitudinal axis has a width and a depth which are each constant along the longitudinal axis.

9. The toothbrush according to claim 1, wherein the width of the constant section is greater than a thickness of the anchor plate by at least 5% and by at most 100%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] To explain embodiments, the drawings show:

[0033] FIG. 1 a perspective view of several rows of holes in a brush head;

[0034] FIG. 2 a perspective view of several rows of holes with an anchor plate inserted;

[0035] FIG. 3 a schematic cross-section of a hole with an anchor plate that is able to insert a bristle bundle into the hole, and a centering section and a constant section of the grooves;

[0036] FIG. 4 a schematic view of the hole shown in FIG. 3;

[0037] FIG. 5 a schematic cross-section of the hole from FIGS. 3 and 4 with an anchor plate that has folded the bristle bundle and inserted it into the hole;

[0038] FIG. 6 a schematic view of the hole shown in FIG. 5;

[0039] FIG. 7 a schematic cross-sectional view of a hole comprising grooves having a taper section, a centering section and a constant section; and

[0040] FIG. 8 a schematic view of the hole shown in FIG. 7.

WAYS OF CARRYING OUT THE INVENTION

[0041] FIG. 1 shows a transparent brush head 1 of an embodiment of the toothbrush according to the invention. The embodiment comprises a plurality of circular cylindrical holes 5 in several rows. The basic shape of the hole in the longitudinal cross-section is thus a circle. Folded bristle bundles (not shown) and a corresponding plurality of anchor plates 3 made of synthetic material are inserted into the holes. The holes are preferably designed as blind holes in the one-piece brush head.

[0042] The brush head 1 further comprises a hole 5 with a longitudinal axis L1 for each bristle bundle. In the present example, all holes 5 are aligned in the same way with their longitudinal axis, namely perpendicular to the upper main surface of the brush head. The small anchor plate 3 is used to anchor the respective bristle bundle and is fixed in the hole 5. The longitudinal axis L1 is here exactly perpendicular to a surface 4 of the brush head.

[0043] According to a favorable embodiment, the hole 5 as such does not taper or widen, i.e. a cross-section of the wall 6 is constant along the longitudinal axis L1 of the hole 5. In other words, the wall is essentially parallel to the longitudinal axis L1.

[0044] Each hole now has two grooves 7 and 8, which are injection molded into the wall 6 of the hole 5, are aligned opposite each other and parallel to the longitudinal axis L1, and are designed to hold the anchor plate 3. The grooves extend from the entrance of the hole 5 or from the surface 4 of the brush head to a depth in the lower half of the hole 5.

[0045] In this embodiment, the alignment of the groove pair of a hole is not parallel to the row of holes, but is instead inclined at an angle of approximately 45 to the direction of the row of holes. This has the advantage that the grooves of adjacent holes are at a relatively large distance from one another.

[0046] FIG. 2 shows the view from FIG. 1, with the exemplary anchor plate 3 fixed here. The anchor plate is essentially rectangular. Preferably, it has no bevels on the sides. This allows the anchor plate to be welded over a large area in the constant section of the grooves.

[0047] When pushed in, the anchor plate 3 is clamped between the grooves 7 and 8, in that the corresponding dimension of the anchor plate 3 is higher by a certain amount than the distance between the bottoms of the grooves 7 and 8, at least in the end position of the anchor plate shown here. The anchor plate 3 is welded to the U-profiles of the grooves 7 and 8, e.g. by friction welding or by ultrasonic excitation of at least one of the components involved.

[0048] In an embodiment, which is shown in FIGS. 3 and 4, the two grooves 9 and 10 run continuously to the bottom of the hole 11. FIG. 4 is a view of the hole 12 and FIG. 3 is a section through the hole 12 in the plane S1. In the upper area, the groove has a centering section Z1, in which the groove base runs at an angle to the longitudinal axis L2. Subsequently, the groove has a constant section K1, in which the groove base is parallel to the longitudinal axis L2. In this way, the fact that a depth T of the grooves 9 and 10, viewed along the longitudinal axis L2 and starting from the surface 13 or the entrance of the hole 12 into the brush head 14, and that during insertion the anchor plate 15 is thereby guided symmetrically into the. In particular, the value of the depth T here ranges from the maximum T2 at the entrance of the hole to the minimum T1 at the end of the centering section Z1. In other words, the depth T of the groove is a distance value in a first plane S1/S2, which runs through the longitudinal axis L2 and perpendicularly through the two grooves. Accordingly, the width B1 is a distance value in a second plane, which runs perpendicular to the first plane.

[0049] FIGS. 3 to 6 now illustrate how the bristle bundle 2 is anchored by the anchor plate 15 in the hole 12. Inserting the anchor plate 15 into the grooves 9 and 10 folds the bristle bundle 2 so that, after the anchoring is complete, the bristles protrude upwards out of the hole 12, see FIGS. 5 and 6. Here, FIG. 5 is a view of the section S2 marked in FIG. 6. It can also be seen how the anchor plate 15 has jammed in the groove.

[0050] Both parts, bristle head 14 and anchor plate 15, are made of plastic, in particular of the same material, and both parts can be welded.

[0051] In this embodiment of FIGS. 3 to 6, there is also another optional aspect that can be used independently of other optional aspects in various embodiments: The width B1 in the combination section of the grooves is wider at the hole edge, in particular at least 5% (e.g. maximum 10%) than the thickness D of the anchor plate 15. Where the combination section meets the constant section, the width of the combination section is the same as the constant section.

[0052] If an even more precise and stable assembly is desired, the grooves can be modified according to the embodiment shown in FIGS. 7 and 8 by also providing a tapering section V. FIG. 7 is a view of the section S3 marked in FIG. 8. This embodiment is based on the embodiment shown in FIGS. 1 and 2. Viewed in the direction of S3, the depth decreases successively. Likewise, the width B of the grooves 16 and 17 decreases successively with increasing distance from the entrance of the hole 20 at the surface 18 of the brush head 19. This additional tapering has the effect that the anchor plate (not shown here) is loaded biaxially centered symmetrically when it is pushed into the grooves when it is inserted into the constant section by friction welding.

[0053] In addition, a further optional aspect is shown in the embodiment according to FIGS. 7 and 8, which can also be used independently of other optional aspects in various embodiments: The centering section Z2 and the tapering section V (only one of the two tapers would also be possible) are both designed in two stages, i.e. a first stage from the brush head surface 18 downwards tapers the groove at a first angle and a second stage, which follows on from the first stage, tapers the groove again, but at a second angle, which is smaller than the first angle. A third phase (constant section K2) up to the deposition of the grooves 16 and 17 is then parallel to the longitudinal axis L3, as shown, but could also be designed obliquely. In the embodiment according to FIGS. 3 to 6, the tapering of the depth of the groove could also be carried out in two or more stages.

[0054] While the invention has been explained in terms of its preferred embodiment(s), many other changes and variations can be made without going beyond the scope of the present invention. Therefore, it is intended that the enclosed claims cover changes and variations within the actual scope of the invention.