FR2976987A1 - Assembling device for fixing seat belt return strap on lining part of passenger compartment of vehicle, has screw whose surface exerts constraint on retaining unit to maintain unit in locking position when device is in service configuration - Google Patents

Abstract

The device has an annular assembling ring (20) whose elastic retaining unit (23) allows a passing position in which a hole of a mechanical element (1) is slidably engaged along an external face of the ring, and a locking position in which the element engaged on the ring is locked in translation along an axis of the ring. The retaining unit occupies the passage position during absence of constraint. A bearing surface of a screw (10) exerts the constraint on the retaining unit to maintain the retaining unit in the locking position when the device is in a service configuration. The ring is made of a plastic material by molding or roto-molding.

Description

FIELD OF THE INVENTION Mounting Device for Rotary and Captive Attachment of a Mechanical Element Field of the Invention The present invention relates to a mounting device for the rotatable and captive fixation of a mechanical element provided with a drilling , such as a seat belt webbing return. Such strap return must indeed be fixed on the upholstery of the passenger compartment of the vehicle to form a point of attachment for the seat belt. Conventionally, the return strap comprises a slot for the passage of the belt of the belt, and a circular bore provided to cooperate with the mounting device to allow a free rotation anchoring on the liner.

BACKGROUND OF THE INVENTION US Pat. No. 7,828,502 discloses such a mounting device comprising a screw and a ring. The screw comprises a head and a rod which has a smooth portion and a threaded portion. The smooth portion which is located between the head and the threaded portion has an annular groove. The mounting ring, not closed on its circumference, has on its inner side a plurality of bosses arranged in the same transverse plane of the ring.

The ring is made of "elastic" steel, that is to say a steel tending to resume its original conformation in the absence of stress. When this ring is held under a spacing constraint, its diameter increases slightly, which allows it to be engaged on the rod of the screw towards his head and come to wrap the smooth portion of the rod. When the stress disappears, the ring gradually resumes its initial diameter and then comes to grip the stem. The bosses then insert into the annular groove of the ring, thus preventing any displacement of the ring in the axial direction of the screw. The mounting ring also has a plurality of resilient retaining tabs uniformly distributed along its circumference. These retaining tongues which are constituted by semi-metal cutouts formed in the material of the ring, protrude from the outer side of this ring with their free ends facing towards the head of the screw. The strap is mounted by sliding it along the screw towards its head. When the webbing return comes into contact with the retaining tabs, it must be pushed forcibly towards the screw head in order to force the tabs to fall back elastically towards the annular surface of the ring, and thus allow this return of strap to continue its movement towards the screw head. As soon as it exceeds the level of the tongues and no longer exerts any effort on them, they straighten to resume their original conformation in which their free ends are now stops for the return strap.

The latter which is trapped between the tabs and the screw head, is thus prevented from moving along the axis of the screw while maintaining the freedom of rotation around this screw. The screw-ring-return strap assembly now secured can then be fixed by screwing the threaded portion of the screw on the internal lining of the passenger compartment of the vehicle. Once assembled, the retaining tabs prevent the return webbing to rub against the inner liner. Unfortunately, it happens quite frequently that the metal tongues do not straighten sufficiently after mounting the webbing return force on the ring, or that they fall back to the annular surface of the ring after repeated shocks. The latter then no longer play their role of stop for the strap return which is free to move in translation and come into contact with the pad.

These movements, combined with the free rotation of the strap back around the screw, then cause many friction with the pad which gradually cause its degradation and the appearance of unpleasant squeaks.

OBJECT AND SUMMARY OF THE INVENTION The present invention therefore aims at providing such a device guaranteeing a secure and durable attachment of the mechanical element after its assembly.

It proposes for this purpose, a mounting device for the rotatable and captive attachment of a mechanical element provided with a bore, said device comprising: - a screw comprising a head and a rod comprising a threaded section; an annular mounting ring comprising at least one resilient retaining member admitting a passage position in which said drilling of a said mechanical element can be slidably engaged along the outer face of the ring, and a locking position in which a said mechanical element engaged on the ring is locked in translation along the axis of the ring while being able to pivot freely around the latter; said device being adapted to adopt a service configuration in which said ring partially surrounds said rod and where it is locked in translation along the axis of said screw; characterized in that said retaining member occupies, in the absence of stress, said passage position; and in that said screw comprises a bearing surface capable of exerting, when said device is in said service configuration, a constraint on said retaining member to maintain it in said locking position.

The restraining member occupying, in the absence of stress, the passage position, the sliding engagement of the mechanical element on the ring is facilitated since it no longer requires any particular effort.

Conversely, once the device in the service configuration and thanks to the stress exerted by the bearing surface of the screw on the retaining member of the ring, this retaining member is held permanently in its position of locking.

Thus, even if it undergoes repeated shocks over time, this retainer can not return to its passage position and the mechanical element will remain locked in translation along the axis of the screw, thus avoiding any friction with the support on which the device according to the invention is to be mounted.

According to preferred features of the device, taken alone or in combination: - said retaining member is a tongue having an elastic hinge hinge urging permanently to said passage position; said tongue comprises an angled end fin oriented towards the outer side of said ring and forming a stop for said mechanical element; said ring comprises four said tongues disposed at one of its axial ends and distributed uniformly around its circumference; - The mounting device is adapted to adopt a mounting configuration wherein said ring is mechanically connected to said screw by connecting means, and wherein said retaining member occupies said passage position allowing the engagement of a said mechanical element. ; said connecting means comprise two deformable annular bosses situated on the internal side of said ring, said bosses being able to trap a collar that includes said rod when said device adopts said mounting configuration; said rod of the screw comprises a smooth section forming an annular groove extending between said collar and said head, and wherein said annular bosses are engaged when said device is in said service configuration; - said bearing surface is formed by the edge of said collar; said ring comprises at least one stop member adapted to cooperate with a said mechanical element engaged on said ring, so that said mechanical element is locked in translation between said retaining member and said stop member when said retaining member occupies said lock position; said abutment member is formed by a flange disposed at one of the axial ends of said ring; said collar is also able to cooperate in abutment with said head of the screw when said device is in said service configuration; said ring is made of a plastic material by molding or rotational molding; said ring is closed on its circumference; and / or - said mechanical element is a seat belt webbing return.

BRIEF DESCRIPTION OF THE DRAWINGS The description of the invention will now be continued by the detailed description of an exemplary embodiment, given below by way of illustration but without limitation, with reference to the appended drawings, in which: FIG. a perspective view of a seat belt webbing return mounted on the lining of the passenger compartment of a vehicle with the mounting device according to the invention; - Figure 2 is an exploded perspective view of the mounting device according to the invention; - Figure 3 is a longitudinal sectional view of the device of Figure 2 in its mounting configuration; FIG. 4 is an enlarged view of detail IV of FIG. 3; - Figure 5 is a view similar to that of Figure 3 wherein a webbing return is engaged on the ring of the device according to the invention; FIG. 6 is a view similar to that of FIG. 5 in which the device according to the invention is in its service configuration, with the strap return which is locked in translation along the axis of the ring while being able to rotate freely around the latter; and - Figure 7 is a view similar to that of Figure 6 but on which the assembly formed by the mounting device according to the invention and the webbing return is mounted on the lining of the passenger compartment of a vehicle.

DETAILED DESCRIPTION OF THE EMBODIMENT The mechanical element illustrated in FIG. 1 is a belt return 1 for a seat belt of a motor vehicle. It comprises a bore 2 (FIG. 5) for its mounting on the internal lining 3 of the vehicle by means of the mounting device 4. With reference to FIGS. 2 to 7, the mounting device 4 according to the invention comprises a screw 10 and an annular mounting ring 20. The screw 10 comprises a head 11 and a rod 12. The rod 12 comprises a smooth section 13 and a threaded section 14, the two sections 13 and 14 being separated by a collar 15. The smooth section 13 which is disposed between the head 11 and the collar 15, has a uniform circular section over its entire length and forms an annular groove. The thread of the section 14 extends from the collar 15 towards the free end of the screw, and stops before this end. Alternatively, it may continue to this end or even stop on a portion of the section 14. The head 11 has a base 16 in the form of disk, surmounted by an engagement stud 17 with section hexagonal adapted to cooperate with a screw key not shown. Alternatively, the engagement stud 17 may have any other form adapted to its cooperation with screwdrivers such as screwdrivers or other. The mounting ring 20 has a cylindrical wall 21 and a collar 22 which projects from the outer face of this wall 21 at one of its axial ends. At its opposite axial end, the ring 20 also has four similar retaining tongues 23 uniformly distributed along its circumference. Each retaining tongue 23 comprises an elastic hinge hinge 24 through which it is connected to the cylindrical wall 21 of the ring 20 (FIG. 4). Each tongue 23 has a curved main wall 25 having the same radius of curvature as the cylindrical wall 21, and a right-angled end wing 26 which is oriented towards the outer side of the ring 20.

The tongues 23 admit, in the absence of stress, a passage position where they each extend towards the inner side of the ring 20. In this passage position, the free end 27 of the fin 26 is located slightly recessed from the outer surface of the cylindrical wall 21 of the ring 20 (Figure 3). The elastic hinges 24 have a dual function of articulation of the tongues 23 on the cylindrical wall 21, and return in the passage position of the same tongues 23. They have a convexity turned on the inner side of the ring 20 (Figure 4).

The ring 20 also has, two annular bosses 28 and 29, located on the inner face of the cylindrical wall 21 and extending in planes perpendicular to the axis of the ring 20. The first boss 28 is disposed near the flange 22, while the second boss 29 is slightly set back tabs 23 near the hinges 24. The ring 20 which is made of a plastic material, can be obtained by molding or rotational molding.

We will now describe the mounting operations of the webbing return 1 on the inner lining 3 of a vehicle in support of Figures 3 to 7. The first step is to pre-assemble the screw 10 and the ring 20 of the device. 4. To do this, the ring 20 is forcibly engaged by its end having the flange 22 on the rod 12 of the screw 10. The minimum internal diameter of the ring 20 (located at the two annular bosses 28, 29, ) being greater than the diameter of the threaded portion 14 of the rod 12, this ring 20 travels without difficulty on the rod 12 until the first boss 28 abuts against the shoulder of the collar 15. The ring 20 must then be force thrust in the direction of the head 11 of the screw 10 so as to elastically deform the first boss 28 and the cylindrical wall 21 to allow the passage of this boss 28 beyond the collar 15. The device 4 is then found in its mounting configuration (figu re 3) in which the screw 10 and the ring 20 are mechanically connected through the collar 15 which is trapped between the two bosses 28 and 29.

The slice 15A of the collar 15 is then able to slide along the inner face of the ring 20, while the inner end of the first boss 28 is slidable along the groove formed by the smooth portion 13 of the rod 12. between the collar 15 and the base 16 of the head 11. On the other hand, the tongues 23 are not biased, they remain in their passage position where they are set back from the outer surface of the cylindrical wall 21. Now, the strap return 1 can be engaged on the mounting device 4. Its bore 2 having a diameter slightly greater than that of the outer surface of the cylindrical wall 21 of the ring 20, the strap return 1 can slide the along the outer face 21A of the ring 20 until one of its lateral faces abuts against the shoulder 22A formed by the flange 22 (Figure 5). Once the return strap 1 so positioned, the latter must then be pushed by force with the ring 20 towards the head 11 of the screw, so as to elastically deform the second boss 29 and the cylindrical wall 21 to allow the passage 15. As soon as the collar 15 exceeds the level of this second boss 29, its edge 15A presses on the retaining tabs 23 which straighten to occupy their locking position in which the curved main walls 25 meet the cylindrical wall 21 of the ring 20, while the end fins 26 now form abutments extending transversely to the axis of the ring 20 (Figure 6). The strap return 1 is thus locked in translation between the fins 26 and the flange 22 which prevent it from moving along the axis of the ring 20 while preserving its freedom of rotation around the same ring 20. In the at the same time, the flange 22 of the ring 20 abuts against the shoulder 16A formed by the base 16 of the screw head 11 (FIG. 6). The mounting device 4 is now in its operating configuration (FIG. 6) in which the ring 20 envelopes the smooth section 13 of the rod 12 and where the same ring 20 is locked in translation along the axis of the screw 10. base 16 in contact with the collar 22 preventing axial movement towards the head 11 of the screw 10 while the collar 15 in contact with the second boss 29 blocks any axial displacement to the threaded portion 14 of the rod 12. The formed assembly by the mounting device 4 and strap return 2 thus associated, can then be mounted on the liner 3, the latter being here fixed by snapping to a metal structure 5 (Figure 7). To do this, the threaded portion 14 of the screw 10 is introduced into a bore passing through the lining 3 and the metal structure 5, then screwed into a clamping nut 6 welded to the inner side of the structure 5 until the collar 15 abut against the periphery of the bore (Figure 7). Once mounted, the webbing return 1 can freely rotate around the screw 10 but is prevented from coming into contact with the gasket 3 by the four fins 26 at right angles to the tongues 23.

Moreover, because these tabs 23 are permanently resting on the edge 15A of the collar 15, they can not, even in case of repeated shocks, retract to return to their passage position.

According to a variant not shown, the ring is not closed on its circumference and it is obtained in a different material than plastic, for example in an "elastic" steel. According to another variant not shown, the retaining tabs have a different conformation and / or their number is different from four, for example equal to two. According to yet another variant not shown, the flange is replaced by a plurality of stop tabs uniformly distributed over the circumference of the ring. According to still other variants not shown, the two annular bosses are each replaced by a plurality of bosses arranged in the same transverse plane of the ring and regularly distributed on the circumference of the ring.

Claims (14)

REVENDICATIONS1. Mounting device for the rotatable and captive attachment of a mechanical element (1) provided with a bore (2), said device comprising: - a screw (10) comprising a head (11) and a rod (12) comprising a threaded section (14); an annular mounting ring (20) comprising at least one elastic retaining member (23) admitting a passage position in which said bore (2) of a said mechanical element (1) can be slidably engaged along the external face (21A) of the ring (20), and a locking position in which a said mechanical element (1) engaged on the ring (20) is locked in translation along the axis of the ring while being able to pivot freely around this last; said device being adapted to adopt a service configuration in which said ring (20) partially envelops said rod (12) and where it is locked in translation along the axis of said screw (10); characterized in that said retaining member (23) occupies, in the absence of stress, said passage position; and in that said screw (10) has a bearing surface (15A) capable of exerting, when said device is in said service configuration, a constraint on said retaining member (23) to hold it in said locking position . 2. Mounting device according to claim 1, characterized in that said retaining member is a tongue (23) having an elastic hinge hinge (24) permanently urging it towards said passage position. 3. Mounting device according to claim 2, characterized in that said tongue (23) comprises a return end wing (26) oriented towards the outer side of said ring (20) and forming a stop for said element. mechanical (1). 4. Mounting device according to one of claims 2 or 3, characterized in that said ring (20) comprises four saidlanguettes (23) disposed at one of its axial ends and uniformly distributed on its circumference. 5. Mounting device according to one of claims 1 to 4, characterized in that it is adapted to adopt a mounting configuration wherein said ring (20) is mechanically connected to said screw (10) by connecting means (15, 28, 29), and wherein said retaining member (23) occupies said passage position allowing the engagement of a said mechanical element (1). 6. Mounting device according to claim 5, characterized in that said connecting means comprise two deformable annular bosses (28, 29) located on the inner side of said ring (20), said bosses (28, 29) being able to trap a collar (15) that includes said rod (12) when said device adopts said mounting configuration. 7. Mounting device according to claim 6, characterized in that said rod (12) of the screw (10) comprises a smooth section (13) forming an annular groove extending between said collar (15) and said head (11). ), and wherein said annular bosses (28, 29) are engaged when said device is in said service configuration. 8. Mounting device according to one of claims 6 or 7, characterized in that said bearing surface is formed by the wafer (15A) of said collar (15). 9. Mounting device according to one of claims 1 to 8, characterized in that said ring (20) comprises at least one stop member (22) adapted to cooperate with a said mechanical element (1) engaged on said ring ( 20), so that said mechanical element (1) is locked in translation between said retaining member (23) and said stop member (22) when said retaining member (23) occupies said locking position. 10. Mounting device according to claim 9, characterized in that said stop member is formed by a flange (22) disposed at one of the axial ends of said ring (20). 11. Mounting device according to claim 10, characterized in that said flange (22) is also adapted to cooperate abutting with said head (11) of the screw (10) when said device is in said service configuration. 12. Mounting device according to one of claims 1 to 11, characterized in that said ring (20) is made of a plastic material by molding or rotational molding. 13. Mounting device according to one of claims 1 to 12, characterized in that said ring (20) is closed on its circumference. 14. Mounting device according to one of claims 1 to 13, characterized in that said mechanical element is a belt webbing return (1).