GB2212390A - Sliding element for vehicle seat rails - Google Patents

Description

Sliding element +or pairs o+ vehicle seat rails The invention relates to a

sliding element +or pairs af vehicle seat rails and having the features set out in the preamble to Claim 1.

direction a+ the rails have been In the past, synthetic plastics bodies of block or strip form disposed at a distance from one another in the longitudinal used as the sliding elements. The sliding elements are intended to per mit both of low- frictian movement during longitudinal displacement of the sliding rails relative to the guide rail and also substantially to eliminate play between guide and slide rails. At the structural tolerances which are involved with pairs of seat rails and the vastly differing loadings which occur on the sliding elements, the known sliding elements do not adequately satisfy either of the aforementioned requirements. Even if the sliding elements are made +ram a synthetic plastics material which, in addition to having the:necessary sliding properties, is also relatively resilient, then if it is intended to ensure an easy and low-friction movement, then it has not hitherto been possible to achieve the desired degree of freedom from clearance. In the unladen state of the seat, particularly, it is not possible to ensure a rattle-free mounting of the slide rail an the guide rail.

The invention is based on the problem of providing a sliding element which guarantees both the desired movement properties and also clearance and rattle-free guidance -under various loadings, particularly also when the seat is not under load.

According to the irventicn, this problem is resolved by a 1.

sliding element having the features indicated in Claim 1.

When the sliding element a=--zr d i ng to dispcsed on that 1Dng.Jtud:úna.1 edge of the rail the invention is a+ the pair of 2 ails which engages into the interior of the U-shaped prof ile and around wh ich engages -a U-shaped marginal portion of the other rail, which surrounds the U-shaped prof i le of the sl idi nc; element, the sl id ing element constitutes a "two-dimensional tolerance equalizing device". In this respect,- the first lip wh i c h extends sideways f rom the bottom edge of one leg of the U-shaped profile represents a first spring travel in a. direction which is cross-wise to the plane of the U-shaped profile, while the- second lip +orms a spring travel in a direction at right angles thereto, namely in a direction which extends parallel with the longitudinal plane of the U-shaped profile or at right angles to the plane a+ the web. The reciprocal engagement of guide ra il and slide rail is therefore sprung both in the direction of the main loading of the rail guide and also transversely thereto. By reason of the shape of the 'sliding element according to the invention, there is no possibility of metallic contact between the two rails even when the resilient lips are in the fully deflected position.

The hardness 0+ the spring action or the spring characteristic can be adapted to the particular circumstances which obtain by appropriately shaping the lips. For example, the dimensions of the resilient lips can vary, for example the material thickness or strength may vary. Instead of extending uninterruptedly along the synthetic-plasti-c body of the sliding element, the lips may be discontinuous and/or perforated. If the lips are sub-divided into a series of serially disposed tongues, then gaps may be provided between the individual tongues.

For the spring effect of the lips, it is not absolutely essential +or the part of the synthetic plastics body which +orms the actual U-shaped profile to form an uninterrupted strip; instead, the legs of the U and/or the web may comprise gaps, perforations or cut-outs.

The invention is described in detail hereinafter with re+erence to an example of embodiment shown in the acr-ornpan,/lng drawings, in which:

i iy C, - 3 P 5 h o w 5 i n cross-section the area. of et".3a.,3erilet-it o+ t in e rails c+ a. pair o+ se a t rails with an inserted sliding elernent according to one embadiment o+ the invention; Fig. 2 is a side view shown or# an enlarged scale in comparisart with Fig. 1, illustrating a middle partion of the length of the sliding element in Fig. 1; Fig. 3 shows a cross-secticn through the sliding element taken on the line III-III in Fig. 2 and Fig. 4 is a side view c) f the s 1 i d i n g e 1 em e n t shch.jrl i n the oppos i te d i rect i on to that in Fig. 2 and on a smal ler scale, illustrating that portion of the sliding element which is between its middle longitudinal portion and one end.

0+ a:pair of seat rails +or a vehicle seat, not shown, Fig. 1 shows a slide rail 1 associated with the vehicle seat and a guide rail 3 which is adapted to be fixed on the vehicle floor in each case just that part which belongs to the marginalportions involved in the mutual engagement, namely an end edge 5 o+ the slide rail 1 and an end edge 7 o+ the guide rail 3. The end edge 5 is bent over through about 180- +rDTn the adjacent part c+ the material c+ the slide rail to form a U-shaped rail. Having a U-shape which is reversed, the end edge 7 c+ the guide rail 3 engages over the free end of the end edge 5.

A sliding element generally designated 9 in Figs. 2 to 4 and constructed in the form of a strip extending in the longitudinal direction c+ guidance and which is seated or& the free. end c+ the end edge 5 forms sliding surfaces f milongitudinal displacement between the end edges 5 and 7 of the sl ide rail 1 or guide rail 3. Further details of t h e examp 1 e embodiment of sliding element 9 as used in Fig. 1 are shown 1,4 Figs. 2 to 4.

In the case c+ the sliding element 9, this is a synthetic plastics body which in a portion a+ its length takes tile +orm c+ a. U-shaped pro+ile. In the case c+ the example shown in Figs. 2 to 4, this is to -be more precise a U-shaped pro+ i l e h av i ng a +ir.st leg- 11, a. second leg 13 and, joining the legs 11, IS at one end, a. w e b 15, t h e. 1 e cj 13 being sub-divided into only three relatively short leg portions3 between which there are extended gaps. 0 n e each o+ the portions c+ the leg 13 is at each end c+ the strip while the third portion o+ the leg 13 is located in the middle, portion c+ the length (see Fig. 4).

Provided on the synthetic plastics body and constructed in one piece therewith are elastic spring lips, namely a +irst lip 21 and a second lip 22, the 4irst lip being di,sposed at the end portion c+ the leg 11 o+ the U while the second lip 22 is disposed at the transition between the other leg 13 o+ the U and the web 15. In the case o4 the example shown in Figs. 2 to 4, the +irst lip 21 +orms an obliquely-outwardly angled extension o+ the leg 11 of:thc- Us the lip 21 having a lesser thickness of material than the adjacent leg 11 c+ the U, in order to impart the required springing properties to the lip 21, having regard to the elasticity properties c+ the synthetic plastics material +rom which thp synthetic plastics body is made. The second lip 22 +orms an obliquely outwardly extending projection which in the unmoulded condition of the lip 22 forms obtuse ang 1 es both with the outside of the adjacent leg 13 c+ the U and also W i th the outs i de o+ the web 15 the angle enclosed with the leg 13 of the U lying, in the case c+ the example c+ embodiment, in the region o+ 120---while the angle enclosed with the web 15 is m+ the order 0+ 15012. Likewise, the thickness c+ material +or the second lip 22 is chosen in the light o+ the desired springing properties and in the case c+ the e x am p 1 e c+ embodiment shown in Figs. 2 to 4, it is less than that c+_the adjacent web 15.

In contrast to the second leg 13 c+ the U which is sub-divided into individual portions, the +irst leg 11 c+ the U is in the region c+ its ree leg and in the case of the example of emb c) d i m ent i 1 lustrated, constructed w it h out any gaps or iterruptions, so that it forms a closed side of a U-shaped ppofile. The shape which is closed in itself is chosen for the leg 11 of the U because it serves as a carrier for the first lip 21, whereas the other leg 13 of the U has only the function & securing the synthetic plastics body in the installed state on the free end portion of the end edge 5 of the slide rail 1, as is shown in Fig. 1. For this last mentioned function, relatively narrow leg portions are adequate, as shown in Figs. 2 and 4. By reason of the spring elasticity of the material of the synthetic plastics body, when in the installed condition, the sliding element 9 is clamped on the end edge 5 when the synthetic: plastics body, during the manufacturing process, in other words during injection moulding or extrusion, is so formed that the legs 11 and/or 13 of the U extend slightly convergingly in the normal way at their free ends 17, as indicated in Fig. 3 by broken lines for the leg 13 so that the legs Ill 13 bear on the lateral faces of the end edge 5 of the guide rail 1, forming a spring clamp.

In order to exclude any possibility of the ends M the sliding element fouling the rail sliding on it, the sliding element 9 is gripped in both end zones, as shown in Fig. 4 +or one end zone, where cham+ers which form the feathered edge are designated 25 and 26. The chamfered edge 25 is constructed as a straight chamfer in the lip 22, extending obliquely towards thre longitudinal axis, so that the height c+ the lip 22 at the outer end of the synthetic plastics body is reduced to virtually nil. Accordingly, the cham+er 26 forms a straight chamfer into the other lip 21 which is likewise reduced virtually to nil by its height at the end. At each end, therefore, the synthetic plastics body of the sliding element 9 is essentially reduced tC the contours c+ the pure U-shaped profile with the legs 11 and 13 and.the web 15 which connects these latter.

As can be seen in Fig. 1 which shows the sliding element 9 in the installed condition, the first lip 21 provides a spring travel for lateral movements within the guide while the second lip 22 constitutes a spring travel +or vertical movements. Thus, - h both "ratt I e-f ree quid:-nce is assured even with relatively large structural tolerances and differing loadings, along with good running properties. It will be appreciated that the leg 11 of the U supporting the first lip 21 could be rendered discontinuous by the use a+ perforations or cut-outs and also the first lip 21 1 c ou 1 d be sub-divided into individual tongues. Likewise, the second lip 22 could be sub-divided into individual tongues. The configuration could also be such that upon sub-division of one or both lips 21 and/or 22 into individual tongues, these would have no gaps between them and would be separated from one another by j ust th i n slits. By the choice of the proportions between the length of the tongues and the length of the gaps between them, SO it is possible to arrange the spring hardness of the lip 21 and/or 22 f ormed from the tongues, as desired. As is evident, hardness will be all the greater the longer are the tongues in proportion to the gaps or, if the relevant lip 21 and/or 22 is uninterrupted, in other words is not sub-divided into individual tonques, as is the case with the example shown. The leg 13 of the U could also be constructed to be continuous over its entire length. In the event of sub-division of one of the lips 21 and/or 22 into individual tongues, this sub-division occurs preferably not in the end zone of the strip but only in the middle portion of the length. This avoids the danger that during displacement of the rails C)ver their entire displacement path, the tongues might abut the rail end which might adversely affect the smoothness of movement.

the spring All the features mentioned in the foregoing description or those which can be ascertained solely from the drawings must be regarded as further developments and therefore constituent parts of the invention, even if they are not particularly stressed and in particular if they are not mentioned in the C 1 aims.

il.

Q P a. t e n t 1 A sliding element for pairs (:) + vehicle S;. a. t rails, in which each pair of rails comprises an e-Iongated guide r. a. i I 'Co, be connected to the floor of the vehicle and, guided fzr longitudinal displacement thereon and adapted to be connected to the seat part, a slide rail, the said sliding element being formed by at least one synthetic plastics body and having, extending between the guide rail and the slide rail a slidincj surface along which, during longitudinal displacement, slides the working surface of a rail of the pair of rails which is towards and bearing on it, charactsrised in that the synthetic: plastics body has in at least a portion of its length the form of a U-shaped profile and in that at least one first and one second elastically resilient lip (21 and 22) is/are provided and project(s) outwardly from the U-shaped profile, the lips being constructed in one piece w i th the U-shaped profile portion, and in that the first lip (21) is disposed in the end portion of one leg (11) of the U while the second lip is disposed at the transition between the other leg (13) of the U. and the web (15) which connects the legs (11 and 13), both lips (21) and (22) each forming a projection extending obliquely beyond the outside of the adjacent leg (ii) of the U or the adjacent web (15).

Claims (1)

1. A sliding element according to Claim 19 characterised in that the first

   lip (21) is constituted by a preferably uninterrupted outwardly angledcver extension c+ the adjacent leg (11) of the U.

   3. A sliding element according t c C 1 a i m 1 c) r 2, characterised in that at least the leg (13) o+ the U which is a4jacent the second lip (22) is sub-divided into a plurality of leg portions which are separated from one another by gaps.

   A sliding element acccrdiri.g to or,--- c+ Claims 1 t o c h ar a c te r i s e d i n that t h e 5 Y n t h e t i c plastics body is 1 constructed in the farm c+ a. strip extending over at least a major part c+ the length c+ the associated rail (I).

   5. A sliding element according to Claim 45 characterised in that both lips (21 and 22) extend over at least a. major part of the length of the strip.

   A sliding element according to one o+ Claims 3 to 5, characterised in that the leg (13) a+ the U which is adjacent the second lip (22) is subdivided into three leg portions c+ which each is located at one a+ the two end portions c+ the synthetic plastics bad), while the third leg pc) rt i c) n is situated in the middle o+ the synthetic: plastics body.

   A sliding element according to one c+ Claims 4 to 6, characterised in that the synthetic plastics body is in at least one a+ its two end zones provided with at least one chamfer -which diminishes the cross-section of the synthetic plastics bod:y towards its end until it is at a minimum value.

   A sliding element according to Claim 75 characterised in that the chamfer is +armed by a straight chamfer c+ one of the lips (21 andlor 22) which reduces the height of the relevant lip (21 andlor 22) towards the end c+ the synthetic plastics body and down to a minimum value.

   A sliding element substantially as described herein with reference to the accompanying drawings.

   Published 1989 at The Patent Office. State House,66"71 High Holborn. London WClR4TP.Further copies maybe obtainedfrom The Patent Office. Wes Branch, St Mary Cray, Orpington, Rent BR5 3RD. Printed by Multiplex techniques Itd, St Mary Cray. Kent, Con. 1/87 1 I;