SEALING GROMMET AND CABLE FEEDTHROUGH CONTAINING A SEALING GROMMET

Abstract

A sealing grommet for a sealed feedthrough of a strand-shaped element through a wall, in particular for a cable feedthrough for the automotive sector, is configured for insertion in an installation direction into an opening, bordered by the wall and with a predefined opening width. The sealing grommet has a grommet body with a push-through area which extends in the installation direction and which is fed through the opening in the installation direction during installation, in such a way that it engages behind the wall in the installed state. An auxiliary element facilitating the insertion into the opening is provided, which has a circumferential sliding area containing at least one sliding surface, and wherein the at least one sliding surface bears at least partially on a circumferential surface of the push-through area.

Claims

1. A sealing grommet for a sealed feedthrough of a strand-shaped element through a wall, the wall having an opening formed therein with a predefined opening width and the sealing grommet being configured for insertion in an installation direction into the opening, the sealing grommet comprising: a grommet body having a push-through area extending in the installation direction and being fed through the opening in the installation direction during installation, in such a way that said grommet body engages behind the wall in an installed state, said grommet body being configured in one piece; and an auxiliary element facilitating the insertion into the opening, said auxiliary element having a circumferential sliding area with at least one sliding surface, said auxiliary element being plugged onto said grommet body, and said at least one sliding surface bears at least partially on a circumferential surface of said push-through area.

2. The sealing grommet according to claim 1, wherein said grommet body, in said push-through area, has a maximum circumferential extent which is greater than or equal to the predefined opening width of the opening, such that said sliding surface, during the insertion, slides along the wall delimiting the opening.

3. The sealing grommet according to claim 1, wherein said grommet body, in said push-through area, widens conically counter to the installation direction.

4. The sealing grommet according to claim 1, wherein said circumferential sliding area is produced from a harder material than said grommet body.

5. The sealing grommet according to claim 1, wherein said auxiliary element is composed of circumference segments, in such a way that, during the installation, said circumference segments can be placed circumferentially onto said grommet body and can thereafter be secured to one another.

6. The sealing grommet according to claim 1, wherein the sealing grommet is composed of two one-piece components, namely said grommet body and said auxiliary element.

7. The sealing grommet according to claim 1, wherein said auxiliary element has a conical basic geometry.

8. The sealing grommet according to claim 1, wherein said auxiliary element, at least in the installed state, has a conical basic geometry with a first portion and, adjoining said first portion counter to the installation direction, a second portion, wherein said first portion has a maximum diameter, which is smaller than the predefined opening width of the opening, and wherein said second portion has a maximum diameter, which is greater than the maximum diameter of said first portion and greater than the predefined opening width of the opening.

9. The sealing grommet according to claim 8, wherein said auxiliary element is ring-shaped and has a plurality of fingers which are distributed about a circumference and which, in the installed state, bear on said push-through area.

10. The sealing grommet according to claim 9, wherein each of said fingers forms a sliding surface.

11. The sealing grommet according to claim 9, wherein said auxiliary element is ring-shaped and has a plurality of stiffening webs which are distributed about a circumference of said auxiliary element and each of said stiffening webs forms a sliding surface.

12. The sealing grommet according to claim 11, wherein: said grommet body has an annular web; and said stiffening webs are formed in said first portion and said fingers are formed in said second portion of said auxiliary element, and in that said first portion bears on said annular web of said grommet body.

13. The sealing grommet according to claim 1, wherein said auxiliary element is detachable or can be pulled off from said grommet body in the installation direction, in such a way that, after the installation has taken place, said auxiliary element is removable in a manner of a repeatedly detachable installation aid.

14. The sealing grommet according to claim 1, wherein in the installed state, the sealing grommet is latched in the opening with an aid of said auxiliary element.

15. The sealing grommet according to claim 1, wherein said auxiliary element is ring-shaped and has a plurality of fingers which are distributed about a circumference of said auxiliary, wherein said fingers form barbs as soon as said auxiliary element is latched in the opening together with said grommet body.

16. The sealing grommet according to claim 1, wherein said auxiliary element is secured on said grommet body by means of a form-fit connection.

17. The sealing grommet according to claim 1, wherein adjacent to said push-through area counter to the installation direction, said grommet body has a wall seat shaped like an annular groove for receiving the wall, and a plate-shaped sealing lip is moreover formed subsequent to the wall seat counter to the installation direction.

18. The sealing grommet according to claim 1, wherein said grommet body is produced from rubber.

19. The sealing grommet according to claim 1, wherein said grommet body is a foam part.

20. A cable feedthrough through a wall having an opening formed therein and with a predefined opening width, the cable feedthrough comprising: a sealing grommet configured for insertion in an installation direction into the opening, said sealing grommet containing: a grommet body having a push-through area extending in the installation direction and being fed through the opening in the installation direction during installation, in such a way that said grommet body engages behind the wall in an installed state, said grommet body being configured in one piece; and an auxiliary element facilitating the insertion into the opening, said auxiliary element having a circumferential sliding area with at least one sliding surface, said auxiliary element being plugged onto said grommet body, and said at least one sliding surface bears at least partially on a circumferential surface of said push-through area.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0044] FIG. 1 is a diagrammatic, perspective view of a sealing grommet composed of a grommet body and of an auxiliary element according to the invention;

[0045] FIG. 2 is a perspective view of the auxiliary element;

[0046] FIG. 3 is a side view of the grommet body;

[0047] FIG. 4 is a sectional view of the grommet body;

[0048] FIG. 5 is a partial sectional view of an alternative embodiment of the grommet body of a second design variant of the sealing grommet;

[0049] FIG. 6 is a partial sectional view of a third design variant of the sealing grommet;

[0050] FIG. 7 is a partial sectional view of the third design variant of the sealing grommet in an installed situation with two wall apertures;

[0051] FIG. 8 is a side view of a fourth design variant of the sealing grommet together with a cable; and

[0052] FIG. 9 is a sectional view of the fourth design variant of the sealing grommet together with the cable.

DETAILED DESCRIPTION OF THE INVENTION

[0053] Parts that correspond to each other are provided in each case with the same reference signs in all of the figures.

[0054] Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a sealing grommet 2 described below and is configured for cable feedthroughs 1 for the automotive sector and is configured for round openings with a defined opening width. Each of the sealing grommets 2 contains a grommet body 4, which is produced for example as a polyurethane foam part and therefore as a one-piece component, or from rubber. As is shown in FIG. 1, an auxiliary element 6 is plugged onto the grommet body 4, the auxiliary element 6 likewise being configured in one piece, but being made of a harder material, for example polyoxymethylene.

[0055] According to an alternative design, the auxiliary element 6 is composed or two semi-circular or half-shell-shaped circumference segments 6a, 6b which, during the installation of the sealing grommet 2, are placed circumferentially on the grommet body 4 of the sealing grommet 2 and are thereafter connected to each other. A design of this kind is shown in FIG. 2, where the intersection between the two circumference segments 6a, 6b of the auxiliary element 6 is indicated by a partition line T.

[0056] Moreover, as a geometric basic body, the auxiliary element 6 has an annular, hollow-cylindrical base 8 which, in the plugged-on state, bears on an annular web RS of the grommet body, and on the inside of which an annular spring 10 is integrally formed. In the plugged-on state of the auxiliary element 6, the spring 10a engages in a groove 12a on the grommet body 4, such that the grommet body 4 and the auxiliary element 6 are connected to each other by a tongue-and-groove connection.

[0057] An alternative connection variant is indicated in the sectional view in FIG. 9, where a groove 12b with an undercut is formed on the grommet body 4. As a complement thereto, the associated spring 10b then has a complementary projection which protrudes into the undercut, such that in this case a combination of tongue-and-groove connection and latching connection is formed between the grommet body 4 and the auxiliary element 6.

[0058] According to FIG. 2, and in a manner similar to a crown, a plurality of in particular plate-shaped fingers 14, teeth or prongs are integrally formed on the annular base 8 of the auxiliary element 6 and are bent slightly outward and thus give the auxiliary element 6 a conical basic geometry. The outwardly directed surface of each finger 14 forms a sliding surface 16 with a low coefficient of friction. The sliding surfaces 16 are here distributed uniformly about the circumference of the auxiliary element 6 and, moreover, are part of a sliding area or of a sliding surface, which facilitates the insertion of the sealing grommet into an opening provided for this purpose.

[0059] This sliding area is also composed of the outwardly directed surfaces of a plurality of stiffening webs 18 which are likewise distributed uniformly about the circumference of the auxiliary element 6 and are formed integrally on the outside of the base 8. Here, the stiffening webs 18 are configured in the manner of small ramps and thus contribute to the conical basic geometry of the auxiliary element 6.

[0060] On account of the conical basic geometry of the auxiliary element 6, and on account of the shape of the grommet body 4, the auxiliary element 6 in the plugged-on state has a first portion A1 formed by the base 8 with the stiffening webs 18 and a second portion A2 formed by the fingers 14, wherein the first portion A1 has a maximum diameter D.sub.D1, which is smaller than the diameter D.sub.Ö1 of the opening, and wherein the second portion A2 has a maximum diameter D.sub.D2, which is greater than the diameter D.sub.Ö1 of the opening. The relationships are indicated in FIG. 7 by dot-and-dash lines. The diameters D.sub.D1 and D.sub.D2 of the auxiliary element 6 correspond to the associated diameters D.sub.D1 and D.sub.D2 of the sealing grommet 2.

[0061] This relationship also applies analogously to the grommet body 4, wherein the portion on which the first portion A1 of the auxiliary element 6 bears in the plugged-on state has a maximum diameter smaller than the diameter D.sub.Ö1 of the opening, and wherein the portion on which the second portion A2 of the auxiliary element 6 bears in the plugged-on state has a maximum diameter greater than the diameter D.sub.Ö1 of the opening.

[0062] In the plugged-on state of the auxiliary element 6, the fingers 14 bear on a sealing lip 20 of the grommet body 4 and, accordingly, the auxiliary element 6 is turned at least partially over the sealing lip 20 of the grommet body 4. The sealing lip 20 here has a ramp-shaped profile and widens conically counter to an installation direction M.

[0063] During the insertion of the sealing grommet 2 in installation direction M into a corresponding wall aperture, the sealing grommet 2 strikes with the sealing lip 20 and the fingers 14 against an annular opening which is delimited by a wall 22 and of which the diameter D.sub.Ö1 is smaller than the maximum diameter D.sub.D2 of the sealing grommet 2 in the area of the sealing lip 20. The sealing lip lies in the push-through area DB which, during the installation, is fed through the opening. As the sealing grommet 2 or rather the push-through area DB is pushed into or through the opening, the fingers 14 are thus deflected inward and compress the sealing lip 20 until the sealing grommet 2 in this area has a diameter smaller than or equal to the diameter D.sub.Ö1 of the opening. After the push-through area DB has passed through this opening, the springs 14 deflect back outward and the sealing lip 20 expands to its original circumference, such that the sealing lip 20 on the one hand and the fingers 14 on the other hand engage behind the opening, as a result of which the sealing grommet 2, as indicated in the illustrative embodiment according to FIG. 7, is latched in the wall aperture.

[0064] In the illustrative embodiment according to FIG. 7, the sealing grommet 2 serves to form a cable feedthrough through two walls 22, wherein the respective openings have different diameters D.sub.Ö1, D.sub.Ö2. In the final installation state, indicated by dashed lines, a plate-like sealing lip 21 then bears flat on each of the two walls 22, and one of the walls 22 is as it were clamped between two sealing lips 20, 21, i.e. a plate-like sealing lip 21 and the sealing lip 20 with the ramp-shaped profile. The wall 22 bears on an annular or cylindrical portion of the grommet body 4 which is positioned as wall seat WS between the plate-like sealing lip 21 and the sealing lip 20 with the ramp-shaped profile. The two plate-like or plate-shaped sealing lips 21 serve here not only as liquid barriers but also as support elements, which bear flat on the walls 22.

[0065] The invention is not restricted to the illustrative embodiment described above. Rather, other variants of the invention can also be deduced by a person skilled in the art, without departing from the subject matter of the invention. In particular, furthermore, all of the individual features described in connection with the illustrative embodiment can also be combined with one another in some other way, without departing from the subject matter of the invention.

[0066] The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: [0067] 1 cable feedthrough [0068] 2 sealing grommet [0069] 4 grommet body [0070] 6 auxiliary element [0071] 6a,6b circumference segment [0072] 8 base [0073] 10a/10b spring [0074] 12a/12b groove [0075] 14 finger [0076] 16 sliding surface [0077] 18 stiffening webs [0078] 20 sealing lip [0079] 21 plate-shaped sealing lip [0080] 22 wall [0081] M installation direction [0082] T partition line [0083] DB push-through area [0084] RS annular web [0085] WS wall seat [0086] A1 first portion [0087] A2 second portion [0088] D.sub.Ö1 diameter of opening 1/wall aperture 1 [0089] D.sub.Ö2 diameter of opening 2/wall aperture 2 [0090] D.sub.D1 diameter of sealing grommet in portion A1 [0091] D.sub.D2 diameter of sealing grommet in portion A2