Suction Hose Connecting Piece

Abstract

A suction hose connecting piece for a suction hose for producing a flow connection from a machine tool to a vacuum cleaner, the connecting piece including a tubular body with a circumferential wall that delimits a flow channel, and a plug section which is arranged on the tubular body for the purpose of producing a plug connection with a mating connecting piece, it being possible to plug the connecting piece and mating connecting piece one onto the other along a longitudinal axis of the plug section, a longitudinal latch contour being arranged on the plug section, counteracting release of the mating connecting piece from the connecting piece relative to the longitudinal axis, and engaging with a longitudinal mating latch contour of the mating connecting piece when the mating connecting piece is plugged onto the connecting piece, along the longitudinal axis of the plug section.

Claims

1. A suction hose connecting piece for a suction hose designed to create a flow connection, from a machine tool to a vacuum cleaner, said connecting piece comprising a tubular body with a circumferential wall which delimits a flow channel and a plug section arranged on said tubular body designed to create a plug connection with a mating connecting piece, wherein the connecting piece and the mating connecting piece can be plugged together along a longitudinal axis of the plug section, wherein a longitudinal latch contour is arranged on the plug section which counteracts detachment of the mating connecting piece from the connecting piece relative to the longitudinal axis and which engages with a mating longitudinal latch contour of the mating connecting piece when the mating connecting piece is plugged onto the connecting piece along the longitudinal axis of the plug section, and wherein at least one rotational form-fit contour is arranged on the plug section in order to create a form-fit connection with a rotational form-fit mating contour of the mating connecting piece, wherein at least one rotational form-fit contour can be brought into or out of engagement with the rotational form-fit mating contour through a relative rotational movement of the connecting piece and the mating connecting piece.

2. The suction hose connecting piece according to claim 1, wherein the longitudinal latch contour comprises an annular, peripheral, groove or an annular, peripheral projection.

3. The suction hose connecting piece according to claim 1, wherein the at least one longitudinal latch contour arranged on an inner periphery of the plug section or an outer periphery of the plug section or wherein the at least one longitudinal latch contour and the at least one rotational form-fit contour are both arranged on an outer periphery or an inner periphery of the plug section, or wherein of the at least one rotational form-fit contour and the at least one longitudinal latch contour, one is arranged on the inner periphery and one on the outer periphery of the plug section.

4. The suction hose connecting piece according to claim 1, wherein the longitudinal latch contour forms a component of an arrangement of at least two longitudinal latch contours which are arranged next to one another or behind one another relative to the longitudinal axis or the longitudinal latch contour comprises a ribbed structure.

5. The suction hose connecting piece according to claim 1, wherein the at least one rotational form-fit contour is arranged, in a plugging direction, behind or in front of the longitudinal latch contour, so that on being plugged onto the connecting piece the mating connecting piece first comes into contact with the longitudinal latch contour and then with the rotational form-fit contour, or vice versa.

6. The suction hose connecting piece according to claim 1, wherein the at least one rotational form-fit contour comprises at least one peripheral rotational form-fit contour running helically or at a right angle, relative to the longitudinal axis of the plug section in the form of a peripheral groove, or a thread or bayonet-type rotational form-fit contour or at least one form-fit cam, designed to screw into a rotational form-fit mating contour running in a peripheral direction around the longitudinal axis of the plug section.

7. The suction hose connecting piece according to claim 1, wherein the at least one rotational form-fit contour comprises at least one inner rotational form-fit contour arranged on an inner periphery of the plug section to accommodate a mating outer rotational form-fit contour arranged on an outer periphery of the mating plug-in connecting piece and at least one outer rotational form-fit contour arranged on an outer periphery of the plug section to accommodate a mating inner rotational form-fit contour arranged on an inner periphery of the plug-on mating connecting piece.

8. The suction hose connecting piece according to claim 7, wherein the at least one inner rotational form-fit contour and the mating inner rotational form-fit contour or the at least one outer rotational form-fit contour and the mating outer rotational form-fit contour have identical contours.

9. The suction hose connecting piece according to claim 1, further comprising at least one latch contour which can be brought into snap-locking engagement or out of snap-locking engagement with a mating latch contour of the mating connecting piece through the relative rotational movement of the connecting piece and the mating connecting piece around the longitudinal axis of the plug section or a longitudinal movement or sliding movement, parallel to the longitudinal axis of the plug section.

10. The suction hose connecting piece according to claim 9, wherein, in order to achieve a spring effect, the at least one latch contour consists of an elastic material or is arranged on an elastic section of the connecting piece or the at least one latch contour comprises a snap-locking recess running transversely to the relative rotational movement or a snap-locking projection running transversely to the relative rotational movement.

11. The suction hose connecting piece according to claim 1, wherein the plug section comprises a softer or more yielding material than the tubular body supporting the plug section.

12. The suction hose connecting piece according to claim 1, wherein at least one of the rotational form-fit contours or at least one latch contour is elastically yielding or arranged on an elastically yielding main plug section body or basic material of the plug section.

13. The suction hose connecting piece according to claim 1, wherein at least one of the rotational form-fit contour or at least one latch contour comprises a harder material than the main plug section body of the plug section carrying the rotational form-fit contour or latch contour.

14. The suction hose connecting piece according to claim 1, wherein the at least one rotational form-fit contour or the at least one latch contour is provided on a form-fit body which comprises a recess which is suitable for deformation of the form-fit body, so that the form-fit body yields on being brought into engagement with the associated rotational form-fit mating contour or mating latch contour, or brought out of engagement with the mating contour.

15. The suction hose connecting piece according to claim 1, wherein the rotational form-fit contours or the at least one latch contour associated therewith can, through the elastic deformation, be brought into snap-locking engagement or out of a snap-locking engagement with the rotational form-fit mating contours or a mating latch contour.

16. The suction hose connecting piece according to claim 1, further comprising at least one form-fit body for forming a form-fit contour the basic material of which is covered, at least in sections in the region of the rotational form-fit contour, with a softer or more elastic material or one with a higher friction coefficient relative to the basic material.

17. The suction hose connecting piece according to claim 1, further comprising a mounting for a suction hose arranged in a fixed manner on the tubular body or mounted on the tubular body so as to be resistant to displacement relative to the longitudinal axis or rotatable, or it forms a component of a suction hose or of a vacuum cleaner or a hand-held machine tool or it forms an adapter for connecting two tubular components, for connecting two suction hoses, or wherein it forms a system comprising the connecting piece and the mating connecting piece.

18. The suction hose connecting piece according to claim 1, wherein its softer material has a hardness of 40/100 Shore A and its harder material has a hardness of 30/100 Shore D or wherein its less elastic material has a modulus of elasticity of 800/2500 N/mm.sup.2 and its more elastic material has a modulus of elasticity of at most 800 N/mm.sup.2, or wherein its more resilient, material has an elongation at break of >70% and its less resilient material has an elongation at break of >30%, or wherein its softer material comprises or is a thermoplastic elastomer or wherein its harder material comprises or is polypropylene or polyamide comprises or its stiffer material or reinforcing material is at least 1.5 times, as stiff as its less stiff material, of the tubular section.

19. The suction hose connecting piece according to claim 1, wherein it comprises a first material which is less electrically conductive than a second material, wherein the second material, at least in sections, projects before the first material in order to create an electrical connection with the mating connecting piece or is arranged before the first material.

20. The suction hose connecting piece according to claim 1, wherein a longitudinal latch contour is arranged on the plug section which counteracts detachment of the mating connecting piece from the connecting piece relative to the longitudinal axis which engages with a mating longitudinal latch contour of the mating connecting piece when the mating connecting piece is plugged onto the connecting piece along the longitudinal axis of the plug section.

21. The suction hose connecting piece according to claim 1, wherein the connecting piece has a tubular section, structured as a multiple-component section, with a longitudinal axis forming or comprising the plug section, wherein, as a second component, at least one elongated stiffening element made of a stiffening material which is harder or which exhibits higher tensile strength or flexural strength or greater stiffness in comparison with the basic material is embedded in a basic material of the tubular section forming a first component.

22. A device with a suction hose connecting piece according to claim 1 wherein the device is a suction hose or a machine tool or a hand-held machine tool or a vacuum cleaner.

Description

[0112] Exemplary embodiments of the invention are explained in the following with reference to the drawing, wherein:

[0113] FIG. 1 shows a side view of a connecting piece with a partially represented suction hose,

[0114] FIG. 2 shows a cross-sectional view through the connecting piece shown in FIG. 1 along a section line AA shown in FIG. 1,

[0115] FIG. 3 shows an exploded view of a variant of the connecting piece shown in FIG. 1, of which

[0116] FIG. 4 shows a plug section,

[0117] FIG. 5 shows a side view of a variant of the connecting piece shown in FIG. 2, onto which, in the illustration according to

[0118] FIG. 6 a mating connecting piece is plugged (cross-sectional view along a section line BB shown in FIG. 5) and into which, in the illustration according to

[0119] FIG. 7 a mating connecting piece is plugged (cross-sectional view along a section line CC shown in FIG. 5),

[0120] FIG. 8 shows an arrangement with the connecting piece shown in FIG. 5 in combination with several different mating connecting pieces which can be connected with and are compatible with the connecting piece,

[0121] FIG. 9 shows a vacuum cleaner with a suction hose, on the free end of which a connecting piece, corresponding for example to the connecting piece shown in FIG. 5, is arranged.

[0122] FIG. 10 shows an enlarged detail view of FIG. 9 from the side,

[0123] FIG. 11 shows a front end of the suction hose of the vacuum cleaner shown in FIGS. 9, 10, wherein a mating connecting piece is plugged onto the connecting piece,

[0124] FIG. 12 shows a variant of the vacuum cleaner shown in FIG. 9, wherein this is equipped with a connecting piece according to the invention, for example in the design shown in FIG. 5,

[0125] FIG. 13 shows a side view of a hand-held machine tool in the form of a grinder, the suction hose connection of which forms a mating connecting piece onto which a connecting piece according to, for example, FIG. 7 is plugged,

[0126] FIG. 14 shows a rear view of a variant of the hand-held machine tool shown in FIG. 13, wherein this is, alternatively, equipped with a connecting piece according to the invention, e.g. the connecting piece shown in FIG. 19 or FIG. 5 or 8,

[0127] FIG. 15 shows a further hand-held machine tool in the form of a power saw to which a suction hose with a connecting piece according to the invention is connected,

[0128] FIG. 16 shows the suction hose connection, i.e. the mating connecting piece, of the hand-held machine tool shown in FIG. 15,

[0129] FIG. 17 shows a first variant according to the invention of the suction hose connection of the hand-held machine tool, wherein this comprises a first connecting piece according to the invention,

[0130] FIG. 18 shows a second variant according to the invention of the suction hose connection of the hand-held machine tool with a second connecting piece, corresponding for example to the connecting piece shown in FIG. 5 or 8,

[0131] FIG. 19 shows the arrangement shown in FIG. 18 with connected suction hose.

[0132] A number of exemplary embodiments of the invention are explained in the following, some of which contain identical or equivalent elements or components. In this case, the same reference numbers are used where possible. Furthermore, features of the connecting piece explained in the following are also advantageous in the mating connecting pieces which match this connecting piece. The mating connecting pieces expediently form system components of a system consisting of connecting piece and mating connecting piece. Some mating connecting pieces are also consistent with the invention if, for example, they have rotational form-fit contours arranged radially on the inside and radially on the outside.

[0133] A connecting piece 10 for a suction hose 100 has for example a tubular body 11. Extending from the tubular body 11 is a plug section 50 designed for the plugging-on of a mating connecting piece 200 as shown in FIG. 6 or for the plugging-in of a mating connecting piece 380 as represented in FIG. 7.

[0134] The tubular body 11 comprises a circumferential wall 12 which defines the limits of a recess 19. A mounting 40 for the suction hose 100 is fitted in the recess 19. The mounting 40, which for example comprises a tubular retaining body 41, is preferably accommodated rotatably in the recess 19. A circumferential wall 43a of the mounting 40 lies for example rotatably mounted against the inner side 14 of the circumferential wall 12 of the tubular body 11. Inside, the retaining body 41 has a retaining structure 43 for retaining the suction hose 100, for example a ribbed structure or a thread into which in particular helical reinforcing ribs—not shown—of the suction hose 100 can be screwed. A foremost, free end face 42 of the retaining body 41 or the mounting 40 lies against the end face of a base 15 of the tubular body 11.

[0135] The mounting 40 is fixed onto the tubular body 12 by a retaining element 45. For example, a supporting flange or a retaining projection 47 is supported on a foremost free end face or narrow side 16 of the tubular body 11. For example, a supporting surface 48 of the retaining projection 47 rests against the free end face 16. A foremost free end face 46 of the retaining element 45 supports an end face 44 of the mounting 40, so that the mounting 40 is sandwiched and/or held in a slide-resistant manner between the retaining element 45 on the one hand and the base 15 of the recess 19 on the other hand.

[0136] In order to ensure a secure hold of the retaining element 45 during use, snap-locking projections or retaining projections 49 are provided which project radially outwards from the retaining element 45 or its main body or retaining body and engage in snap-locking recesses or retaining recesses 13 of the tubular body 12. Preferably, the retaining projections 49 are resilient springs or designed in the form of snap-locking tabs, so that they can be forced inwards in the direction of the recess 19 in order to detach the retaining element 45 from the tubular body 12.

[0137] It should be understood that in one embodiment—not shown—the tubular body 11 can integrally incorporate the retaining structure 43, that is to say it can accommodate and hold the suction hose 100 directly.

[0138] The tubular body 11 and/or the retaining element 45 and/or the mounting 40 are preferably made of a relatively hard plastic material, for example polypropylene. This readily guarantees the strength necessary in order to hold the suction hose 100. However, it is also possible that for example the retaining element 45 and the tubular body 11 are made of a harder material than the mounting 40 for the suction hose 100. In any case, the connecting piece 11 is harder in the region of the tubular body 11 than in the region of the plug section 50, the basic material of which is a plastic with low hardness and in particular with greater flexibility or elasticity. For example, the basic material of the plug section 50 is thermoplastic elastomer.

[0139] Nonetheless, the plug section 50 also has a relatively high flexural strength, in any case a higher flexural strength than would be the case if only thermoplastic elastomer were used. A stiffening structure 20 with several stiffening elements 21 is provided for stiffening purposes. The material of the stiffening elements 21 is harder and/or has greater tensile strength and/or flexural strength and/or is stiffer than the basic material of the plug section 50. Preferably, the material of the stiffening elements 21 is at least 1.5 times, preferably 2 to three times or even four times harder or stiffer than that of the section of the connecting piece stiffened by means of the stiffening elements 21, for example of the plug section 50. The plug section 50 forms a tubular section 35. The plug section 50 is designed for a complementary mating plug section to be plugged onto or into it, and is thereby on the one hand elastically yielding in order in this way to make possible an optimal form-fit and an optimal seal with the mating connecting piece; on the other hand it is relatively stiff transversely to the longitudinal axis L or plugging axis. Incidentally, it should be noted that of course the tubular body 11 can also be designed in the manner of the plug section 50 or tubular section 35, even though this is not shown in the drawing, i.e. stiffening elements can for example consist of a relatively soft material.

[0140] The basic material of the plug section 50 forms an inner component 52 and an outer component 51 which advantageously completely encases the stiffening elements 21, which are strip-formed. The stiffening elements 21 project from the tubular body 12 forming a connecting section 25 or connecting body for the stiffening elements 2 in the direction of the plug section 50 in the manner of strips or lamellae. A circumferential gap 24 is provided between each of the stiffening elements 21, so that the stiffening elements 21 are spaced apart in a peripheral direction. The stiffening elements 21 can thus approach closer to one another in a peripheral direction or can be spread apart, so that a cross section of the plug section 50 can be reduced in size or enlarged when the plug section 50 is plugged onto a mating connecting piece 300 or plugged into a mating connecting piece 200.

[0141] In addition, the moveability or elasticity of the plug section 50 is further improved in that the free end regions 23 of the stiffening elements 21 are narrower than their foot regions or other longitudinal end regions 22 which are connected with the tubular body 12. As already mentioned, the tubular body 12 forms a connecting body for the stiffening elements 21, so that these are connected with one another at one longitudinal end and can be moved towards or away from one another at their free longitudinal end regions 23 in order to enlarge or reduce the cross section of the plug section 50.

[0142] The stiffening elements 21 are round in cross section, the radius corresponding approximately to the radius of the tubular body 11. The fact that the contour of the stiffening elements 21 is not flat in cross section but rounded or angled increases the stiffening effect.

[0143] The stiffening elements 21 and the tubular body 11 consist for example of polypropylene, in any case one of the relatively hard materials mentioned above. In contrast, the inner component 51 and the outer component 52 are softer and more elastic, being for example made of rubber or of an elastomer, in particular a thermoplastic elastomer.

[0144] The inner component 52 and the outer component 51 of the plug section 50 accommodate the stiffening structure 22 integrally, that is to say the stiffening elements 21 are so to speak sandwiched between the inner component 52 and the outer component 51. Expediently, the inner component 52 and the outer component 51 are sprayed in sequence onto the stiffening structure 20 and thus onto the tubular body 11.

[0145] For this purpose, two or more spraying operations are for example carried out in which for example the inner component 52 is first sprayed or moulded onto the stiffening elements 21, followed by the outer component 51. According to a preferred production variant, the inner component 52 is sprayed or cast first, followed by the stiffening elements 21, in particular also, in a single pierce, the tubular body 11, and then the outer component 51.

[0146] In such a spraying process, webs 53 are for example formed which fill out the spaces or gaps between the stiffening elements 21, i.e. the circumferential gaps 24. Between the webs 53 are wall sections 54 which cover the so to speak radially inner side of the stiffening-elements 21. The wall sections 54 are somewhat thinner in comparison with the webs 53, for example skin-like. However, they preferably cover the inner side of the stiffening elements 21 completely, so that this is covered with the elastic material of the inner component 52 in the region of a plugging recess 55 of which they form the radial outer limit.

[0147] Expediently, the outer component 51 is also provided with webs 53, between which are wall sections 57. The wall sections 57 cover the outside of the stiffening elements 21, thus forming an outer wall of the plug section 50, while the webs 53 of the outer component 51 and the inner component 52 connect with one another and fill out the spaces or gaps between the stiffening elements 21. It can be seen that, due to the elastic material of the outer component 51 and the inner component 52, the webs 53 are elastically yielding, so that the stiffening elements 21, which are blade-like or lamellar in form, can move towards or away from one another, at least in the region of their free longitudinal ends 23. This moveability is further facilitated in that the lateral distance 24 between the stiffening elements 21 is greater in the region of the free longitudinal ends 23 than in the region their other longitudinal end regions or foot regions 22.

[0148] FIG. 4 illustrates the complete plug section 50, i.e. in the state in which the inner component 52 is already joined with the outer component 51. As a result of the spraying process by means of which the two components 51, 52 are produced being carried out as quickly as possible, the basic material of the plug section 50 combines as far as possible homogeneously. It is also conceivable that the plug section 50 as a whole is sprayed or cast onto the stiffening structure 20 or the tubular body 11 (in one spraying or casting operation). In any case, cavities 59 for the stiffening elements 21 are provided on the plug section 50 or its main plug section body 60.

[0149] In addition, there is a ribbed structure 56 located on an inner periphery of the plugging recess 55 which is expediently formed by the elastic or elastomeric material of the inner component 52 and which can ensure a firm grip and/or a good seal, for example on a relatively smooth connecting tube or mating connector 505 of the hand-held machine tool 500 shown in FIGS. 15,16. For example, the connector element 505 can be plugged into the plugging recess 55 or the connecting piece 10 can be plugged onto the mating connecting piece 505.

[0150] The ribbed structure 56 comprises one or more annular, in particular peripheral, longitudinal latch contours 61, for example grooves 62. These make possible a longitudinal snap-locking engagement with mating longitudinal latch contours 302 on a plug section 301 of the mating connecting piece 300 which can be plugged into the plugging recess 55. The mating connecting piece 300 can for example be connected with a suction hose, a hand-held machine tool or the like by means of clamping arms or retaining arms 303, between which gaps 304 are expediently present. On the retaining arms 303 there is a for example a thread or a snap-locking structure 305 for screwing or snap-locking together with a connector element, in particular of a suction hose or a hand-held machine tool or of a vacuum cleaner. This is to be understood as being purely by way of example, since it is the plug section 301 which is important here, whereas the other side 307 with for example the retaining arms 303 could perfectly well be of an alternative design. It is for example possible that the side or the section 307 forms an integral component of a hand-held machine tool, of a vacuum cleaner or the like.

[0151] The mating connecting piece 300 can for example be a component made of polypropylene or another hard plastic. However, the elastically yielding plug section 50 of the connecting piece 10 yields somewhat when plugging in the plug section 301 of the mating connecting piece 300, for example in the sense of widening, so that the ribbed structure 56 and thus the longitudinal latch contours 61 can come into engagement with the mating longitudinal latch contours 302 and hold these in a direction of pull or direction of a longitudinal axis L of the plug section 50. At the same time, an optimal frictional connection is created because, expediently, the basic material of the plug section 50 has a high friction coefficient, in any case a higher friction coefficient than the material of the tubular body 11.

[0152] The relatively soft, in any case yielding plug section 50 can also widen or yield to such an extent that a mating connecting piece 350 with rotational form-fit mating contours 352 on its plug section 351 can be plugged into the plugging recess 55. These rotational form-fit contours interact with rotational form-fit contours 75 of the connecting piece 10, namely with form-fit projections 26 projecting inwards into the plugging recess 55. The mating connecting piece is illustrated in FIG. 8.

[0153] It is for example conceivable that a foremost section of a connecting piece 380 corresponding approximately with the connecting piece 300 has rotational form-fit mating contours 352, as indicated in FIG. 7. The rotational form-fit mating contours 352 can be brought into engagement with the rotational form-fit contours 75 or the form-fit projections 26 of the connecting piece 10.

[0154] The form-fit projections 26 could for example be formed integrally by the basic material of the main plug section body 60, for example by the inner component 52. However, in the present case the configuration is such that the form-fit projections 26 are arranged on the stiffening elements 21 and project into the plugging recess 55 of the connecting piece 50 through openings 58 in the inner component 52. Here, they form cams which can be brought into engagement with the rotational form-fit mating contours 352 or the rotational form-fit contours 70 which will be described below. In principle, the rotational form-fit mating contours 352 correspond in geometry and form with rotational form-fit contours 70 on the outer periphery of the plug section 50 or of the connecting piece 10, which will be explained in more detail below.

[0155] The form-fit projections 26 can for example comprise form-fit parts 27 and 28 which are arranged on adjacent stiffening elements 21. The form-fit parts 27 and 28 can, as illustrated in FIG. 3, be separate components which are however connected with one another through the inner component 52 or the outer component 51. Thus, a section with elastic plastic or the like can for example be located between the form-fit parts 27 and 28.

[0156] A preferred exemplary embodiment is indicated in FIG. 2, in which form-fit parts 27′ and 28′ are connected together so to speak to form a single form-fit projection 26 with a section 26′. However, between the part sections or parts 27′, 28′ there is also an opening 29, so that while the part sections or parts 27′, 28′ bridge the circumferential gap 24 between the stiffening elements 21 on which they are arranged with the section 26′, they are movable relative to one another due to the opening 29. The form-fit projection 26 according to the embodiment shown in FIG. 2 is thus formed on the basis of two form-fit parts 27′ and 28′ which are arranged on adjacent stiffening elements 21 which however, due to the opening 29, hinder the relative movement of the stiffening elements 21 towards or away from one another less than a so to speak solid form-fit projection 26 would. The opening 29 is expediently filled with elastic material, for example the inner component 52, but could also be free, that is to say it could only contain air, so to speak.

[0157] Also, as in the exemplary embodiment shown in FIG. 6, slot-like openings 29′ can be provided in a form-fit projection 26.

[0158] The form-fit projections 26 project inwards through openings 58 from the inner component 52 into the plugging recess 55. The form-fit projections 26 are thus formed from a relatively hard material, for example polypropylene, which guarantees a high dimensional accuracy and strength.

[0159] It should be understood that the form-fit projections 26 can also be at least partially encased in the material of the main plug section body 60, as indicated in FIG. 4. For example, the form-fit projections 26 next to the opening 58 or in the region of the opening 58 in the wall section 58′ for example of the inner component 52 are at least partially, or completely covered. The relatively soft material of the wall section 58′ increases for example the frictional connection with associated mating form-fit contours, for example the rotational form-fit contours 70, which will be explained below.

[0160] The rotational form-fit contours 70 comprise a peripheral rotational form-fit contour 71, which is for example designed to engage with the form-fit projections 26. The form-fit projection 26 forms for example a rotational form-fit body 75.

[0161] The connecting piece 10 can be connected to and locked together in a form-fit manner with an equivalent, so to speak compatible connecting piece 10 through the plugging/rotational movement which will be described below. By way of example, the connection with a mating connecting piece 200, which is illustrated in cross section in FIG. 6, is explained in the following. The mating connecting piece 200 has for example, on a circumferential wall 201 limiting its plugging recess 255, rotational form-fit mating contours 276, for example cams, projections or the like, which project inwards into the plugging recess 255. Further rotational form-fit mating contours 275 are provided on the outer periphery of the plugging recess 255 or on the outer periphery of the circumferential wall 201, which for example fit into rotational form-fit contours of a connecting piece designed in the form of grooves.

[0162] A rotational form-fit mating contour 276 can be introduced into the peripheral rotational form-fit contour 71 through a longitudinal guide contour 80. This takes place for example if the mating connecting piece 200 is plugged onto the connecting piece 10, i.e. onto its plug section 50.

[0163] The rotational form-fit mating contour 276 is for example designed in the form of a substantially cuboid block or lug. However, the functionality of the rotational form-fit mating contour 276 is also provided by each of the form-fit projections 26, wherein the form-fit projections 26 which form the rotational form-fit contours 75 are matched even more optimally to the inner contour or form-fit contour of the peripheral rotational form-fit contour 71.

[0164] The longitudinal guide contour 80 is for example designed in the form of a slot or guide channel. The rotational form-fit contour 75 or the rotational form-fit mating contour 276 can be moved along side walls or side surfaces 81, 82 of the longitudinal guide contour in the direction of the peripheral rotational form-fit contour 71 or out of this along the longitudinal axis L. The longitudinal guide contour 80 and the peripheral rotational form-fit contour 71 are for example oriented approximately at right angles or in a hook-like form relative to one another. The gaps between the side walls 81, 82 are preferably so wide that there is still a certain amount of play between the side surfaces 78 of the rotational form-fit contour 75, namely a form-fit projection, and the side walls or side surfaces 81,82, while providing longitudinal guidance in the direction of the longitudinal axis L.

[0165] A side surface or side wall 72 and a side wall or side surface 74 of the peripheral rotational form-fit contour 71 opposite this, designed in the form of a groove or slot, preferably converge together in the direction of an end wall 73, that is to say the end region of the peripheral rotational form-fit contour 71, so that the peripheral rotational form-fit contour is somewhat narrower in the region of the end region or the end wall 73 than at its opening onto the longitudinal guide contour 80. As a result, the rotational form-fit contour 75 or rotational form-fit mating contour 276 received between the side surfaces or side walls 72, 74 is so to speak clamped tight or at least fixed in place relative to the longitudinal axis L.

[0166] During the course of a plugging movement, the rotational form-fit body 75 or the rotational form-fit mating contour 276 are thus introduced along the longitudinal axis L into the longitudinal guide contour 80, wherein a marking 84 or an index facilitates the introduction of the rotational form-fit body 75 or the rotational form-fit mating contour 276.

[0167] At the end of this plugging movement along the longitudinal axis L, the form-fit body 75 or the rotational form-fit mating contour 276 comes to rest against the longitudinal end region 83 of the longitudinal guide contour 80. The connecting piece 10 and the mating connecting piece 275 or a complementary connecting piece 10 carrying the form-fit body 75 then need to be rotated relative to one another around the longitudinal axis L, whereby the form-fit body 75 or the rotational form-fit mating contour 276 is then twisted into the groove or peripheral rotational form-fit contour 71. The rotational movement ends when the form-fit body 75 or the rotational form-fit mating contour 276 comes to rest against the longitudinal end region 83 or end wall 73 of the peripheral rotational form-fit contour 71. This rotary end position is indicated by a further marking 85.

[0168] Form-fit surfaces or side surfaces 76, 77 of the rotational form-fit contour 75, for example of the form-fit projections 26, associated with the side walls 72, 74 preferably run obliquely to one another, in correspondence with the position of the side walls 72, 74, which in addition further reinforces or improves the aforementioned wedging effect or clamping when the rotary end position or the rotary form-lock has finally been reached.

[0169] The side surface 76 and the side wall 72 are designed as sloping surfaces 76a, 72a or have sloping surfaces 76a, 72a which, on rotation of the connecting piece 10 relative to a mating connecting piece, for example a mating connecting piece 10 of similar design (see FIG. 2) or the mating connecting piece 200, i.e. if the two components are rotated around the longitudinal axis L relative to one another, result in an axial adjustment or displacement of the two components towards one another along the longitudinal axis L. The user thus only needs to rotate the connecting piece 10 and/or the mating connecting piece in order to displace the two components relative to one another along the longitudinal axis L, in particular to clamp them together. It should be understood that one of the sloping surfaces 76a or 72a is sufficient for such a displacing effect or clamping effect.

[0170] A latch contour 86, for example a rib 87, is also provided between the longitudinal guide contour 80 and the peripheral rotational form-fit contour 71. If the rotational form-fit mating contour 276 or the rotational form-fit contour 75 is to be moved out of the longitudinal guide contour 80 into the peripheral rotational form-fit contour 71 or out of this in the direction of the longitudinal guide contour 80 it must so to speak be moved past the latch contour 86. A snap-locking engagement thus takes place in a rotary direction or peripheral direction around the longitudinal axis L which secures the rotational form-fit connection.

[0171] The rib 87 is preferably made of the softer or more elastic material of the main plug section body 60, so that it is elastically yielding and thus allows the rotational form-fit contour 75 or the rotational form-fit mating contour 276 to be moved past it.

[0172] In addition to the longitudinal latch contours 61 in the plugging recess 55 described above, longitudinal latch contours are also provided on the outer periphery of the plug section 50, namely longitudinal latch contours 90. The longitudinal latch contours 90 comprise for example a peripheral groove 91 which so to speak intersects with the longitudinal guide contours 80. A so to speak imaginary course 92 of the peripheral groove 91 is indicated in FIG. 1. The peripheral groove 91 thus communicates with the longitudinal guide contours 80 (3 longitudinal guide contours 80 are provided at an angular distance, preferably an identical angular distance, from one another), through this is not an essential feature. In any case, longitudinal latch contours 90 provided in or on the radially outer periphery of the plug section 50 can be snapped into a mating latch contour, for example in the manner of a ribbed structure, of an annular snap-locking projection projecting radially on the inside into a plugging recess of a mating connecting piece, of a hook or the like, in order to connect the connecting piece 10 with the mating connecting piece—not shown—so to speak in the direction of pull or longitudinal direction.

[0173] In the exemplary embodiment shown in FIGS. 5, 6 and 7 it is expediently the case that the plug section 50, in particular the outer component 51, is electrically conductive. This allows static electricity to be dissipated, for example.

[0174] However, a relatively hard plastic is particularly suitable in terms of being electrically conductive. In this case, through the multiple-component design of the connecting piece 10 in the embodiment shown in FIGS. 1 and 2, the necessary electrical conductivity can nonetheless be provided in a particularly convenient manner if corresponding openings are provided in the more elastic component or soft component which are passed through by parts of the harder component, which is electrically conductive. For example, an electrical contact arrangement 30 with electrical contact sections 31, 32 is provided which projects radially outwards from the outer component 51. The rib 87 or latch contour 86 and/or at least one of the form-fit projections 26 can be designed as an electrically conductive component. Preferably, further electrical contact surfaces 33 are provided, for example in the region of the ribbed structure 56, so that on the one hand the form-fit projections 26, and on the other hand these further contact surfaces 33 are available in order to create an electrical connection, in any case inside the plugging recess 55.

[0175] At this point it should be noted that the latch contour 86 or rib 87 can also be formed by one relatively hard component of the connecting piece 10, for example in the form of a projection on one of the stiffening elements 75 which projects from the outer component 51.

[0176] Preferably, in a connecting piece according to the invention, several peripheral rotational form-fit contours and possibly several longitudinal guide contours communicating with these are provided. For example, in the connecting piece 10 three such configurations are provided spaced at equal angular intervals 3. For the same reason, 3 form-fit projections 26 or rotational form-fit contour 75 are also provided, arranged at the same angular intervals.

[0177] While the rotational form-fit contours 70 so to speak form outer rotational form-fit contours, the rotational form-fit contours 75 are so to speak inner rotational form-fit contours. Naturally, it is possible that, as for example in the mating connecting piece 200, which one can also regard as a connecting piece in the sense of the invention, rotational form-fit contours of the same type, namely the cam-like rotational form-fit mating contours 275, 276 are provided both on the inside and on the outside in the region of the plugging recess 255. Here too, 3 inner rotational form-fit mating contours 276 arranged at the same angular distance from one another are provided, as well as outer rotational form-fit mating contours 275.

[0178] In contrast, the mating connecting piece 52 has a circumferential wall 278 which defines the limits of a plugging recess 255 but does not have any rotational form-fit contours or rotational form-fit mating contours. This is also typically the case with known hand-held machine tools, for example in the variant illustrated in FIG. 16. However, the plug section 50 can also be plugged into the plugging recess 255 of the mating connecting piece 250 and can thereby be compressed, so that it adapts optimally to the inner contour of the plugging recess 255.

[0179] In the exemplary embodiments described so far, the connecting piece according to the invention is represented as a component arranged for example on the suction hose 100. However, it can also be a component of a vacuum cleaner or a hand-held machine tool, as will be made clear in the following.

[0180] For example, a connecting piece according to the invention 10 is located at the free end of a suction hose 100 of a vacuum cleaner 600 shown in FIG. 9. The suction hose connection 605 of the vacuum cleaner 600, which is for example arranged on the front side 602 of its housing 601, can be of conventional design. For example, the suction hose 100 is plugged onto the suction hose connection 605. The other connection of the suction hose 100, intended for example for connecting with the hand-held machine tool 700 or 500, is provided with the connecting piece 10 (FIG. 10), whereby the rotational form-fit contours 70 provided therein as well as the latch contour 86 guarantee an optimally secure connection to the connected hand-held machine tool.

[0181] Naturally, only the mating connecting piece 52, for example, can be plugged onto the connecting piece 10.

[0182] However, it is also possible that the connecting piece according to the invention 10 is for example provided on the vacuum cleaner 600 instead of the suction hose connection 605 with for example only one bushing or one sleeve (FIG. 12). In this case, this can for example be provided for the connection of a mating connecting piece 200 or of a connecting piece 10 of the same type, in order to make possible a more secure gripping of the suction hose 100. However, in the exemplary embodiment shown in FIG. 12, a suction hose 100 with a mating connecting piece 250 is connected to the connecting piece 10 of the vacuum cleaner 10.

[0183] A hand-held machine tool 700, for example a grinder, has a drive motor 702 for driving a grinding tool 703. During operation of the hand-held machine tool 700, dust is produced which is passed through a dust guidance channel 704, which runs through the housing 701, in the direction of a dust outlet 705. A connecting piece according to the invention 10 can be connected to this, for example to the dust outlet 705, which for example has a ribbed structure like for example the mating connecting piece 380 (FIG. 13). Alternatively, however, it is also possible, as illustrated in FIG. 14, that for example a connecting piece 707 with rotational form-fit contours 75 is provided. The rotational form-fit contours 75 can for example be brought into engagement with the rotational form-fit contours 70 of a connecting piece according to the invention 10.

[0184] In the hand-held machine tool 500 shown in FIGS. 15-19, a conventional connecting tube can for example be provided as the mating connecting piece 505, as illustrated in FIG. 16. Its circumferential wall 506 delimits for example a plugging recess 507, into which the connecting section 50 of a connecting piece according to the invention 10 can be plugged, see for example FIG. 19. For example, a motor 502 arranged in the housing 501 of the hand-held machine tool 500 drives a tool 503, for example a saw blade.

[0185] Alternatively, as illustrated in the FIGS. 15 and 17, a mating connecting piece 550 can be arranged on the end of a dust guidance channel 504 of the hand-held machine tool 500. For example, dust, chips or the like produced during operation of the hand-held machine tool 500 flow through the dust guidance channel 504. On the mating connecting piece 550, rotational form-fit mating contours 576 are arranged radially on the inside and rotational form-fit contours 575 are arranged radially on the outside of a circumferential wall 577 which forms the limits of a plugging recess. Thus, both when plugging on and when plugging in a connecting piece according to the invention, for example the connecting piece 10, rotational form-fit mating contours are provided which guarantee a particularly secure hold resistant to tensile forces relative to the longitudinal axis L.

[0186] At this point it should be mentioned that the mating connecting piece 550 can consist exclusively of relatively hard plastic and represent a connecting piece in the sense of the invention, since it has rotational form-fit contours or rotational form-fit mating contours arranged both radially on the inside and radially on the outside of its plug section.

[0187] In the exemplary embodiment shown in FIG. 18, a connecting piece 10 is arranged, for example permanently or detachably, on the dust outlet of the hand-held machine tool 500. This preferably consists of a hard component and a soft component, as explained, and/or has on its plug section both the longitudinal guide contour 80 and also the rotational form-fit contour 70, so that a particularly secure hold of the mating connecting piece 200 for example is possible.

[0188] The circumferential wall 201 can consist of a relatively hard plastic, for example polypropylene. In contrast, the plug section 50 designed to be plugged into the plugging recess 255 inside the circumferential wall 201 consists, at least on its outer periphery, of a comparatively softer plastic, as a result of which a particularly secure, friction-locking hold and in addition also a good seal can be achieved. However, it is also quite possible that the circumferential wall 201 also consists of soft plastic, in particular of the same plastic material as the plug section 50. It is also conceivable that the circumferential wall 201 is stiffened by means of stiffening elements in the manner of the stiffening elements 21. For example, strip-formed stiffening elements 221 are provided. The stiffening elements 221 are inclined obliquely relative to the longitudinal axis L, i.e. unlike the stiffening elements 21 they are not oriented parallel to the longitudinal axis L. Both in the variant with a hard circumferential wall 201, i.e. a hard plug section 250, and also with a plug section 250 which is soft or stiffened with stiffening elements 221 or 21, the mating connecting piece 200 in each case represents an optimisation in comparison with known connecting pieces or mating connecting pieces. The mating connecting piece 200 can for example form a component of the hand-held machine tool 500 or 700 or also of the vacuum cleaner 600, for example in each case as a connection for the suction hose.