GB2108836A

GB2108836A - Rail mounting for vehicle seats

Info

Publication number: GB2108836A
Application number: GB08231642A
Authority: GB
Inventors: Burckhard Becker; Alfred Gedig; Ernst-Reiner Frohnhause; Heinz Bauer
Original assignee: C Rob Hammerstein GmbH
Current assignee: Johnson Controls Metals and Mechanisms GmbH and Co KG
Priority date: 1981-11-09
Filing date: 1982-11-05
Publication date: 1983-05-25
Also published as: GB2108836B; FR2516026A1; SE453478B; SE8206179L; SE8206179D0; ZA828168B; DE8132719U1

Abstract

The invention relates to a sliding rail device, particularly for use in adjusting motor-vehicle seats in position longitudinally, the device comprising two rails, one of which slides along the other, guided by guiding means. Each rail is essentially U-shaped in cross-section and comprises, as seen in cross-section, an elongated base (24) and two shorter arms (25). The bases of the two rails extend parallel to each other and the arms of the one rail overlap the arms of the other, so that an inner chamber (27) is formed. At least one arm (25) of each rail (20, 21) terminates, as seen in cross-section, in an envelopment flange (29) which is angled to form a hook; the envelopment flange (29) of one of the rails (20, 21) penetrates inwards into the hook region (30) formed between the envelopment flange (29) and the arm (25) of the other rail (20, 21). The rail device is preferably installed in the vehicle so that the base (24) of each rail is vertical. <IMAGE>

Description

SPECIFICATION Rail mounting for vehicle seats The invention relates to a sliding rail device, particularly for use in adjusting motor vehicle seats in position longitudinally, the device comprising two rails, one of which slides along the other, guided by guiding means; each rail being essentially U-shaped in cross section and comprising, as seen in cross section, an elongated base and two shorter arms; the bases of the two rails extending parallel to each other; the two U's of the cross section facing each other, the arms of the one rail overlapping the arms of the other, so that an inner chamber is formed. The invention also relates to a vehicle, in particular a motor vehicle, equipped with the device.

A sliding rail device of this kind is used in Opel motor-cars. In this known device each of the two rails has an essentially U-shaped cross section.

The two arms of the U of the one rail overlap the two arms of the U of the other rail, so that there is an outer rail and an inner rail. The arms of both rails have guiding grooves in which roll guide members in the form of guide-balls, which are retained in the grooves by the pre-stressing of the arms, i.e. the balls are retained resiliently in the grooves. The known sliding rail device is installed in the vehicle with the bases of the U's substantially horizontal, the two balls, as seen in cross section, occupying a common horizontal plane.

This known sliding rail device has insufficient tear-apart strength, i.e. the two rails separate too easily from each other under the influence of the pull applied by a safety seat-belt in the event of a motoring accident. This applies particularly to the sliding rail device at the tunnel side of the seat, where the tear-apart stress is about twice what it is on the door side. Thus the sliding rail device on the tunnel side of the seat has to take about one quarter of the total stress in the case of a 3-point safety seat-belt attachment.

The known sliding rail device slides easily and has no tendency to jam. This is partly because only two guide-balls are used, as seen in cross section, each ball rolling in a pair of parallel guiding grooves, and partly because the arms of the one rail embrace the arms of the other, i.e. an outer rail embraces an inner one.

The tear-apart strength of the known device is reduced simply by a high instantaneous passenger load, which can considerably stress the structure.

A high downwards load spreads the arms of the outer rail apart, at the same time squeezing the arms of the inner rail together, and this can reduce the tear-apart strength of the structure.

The intention in the present invention, starting out from the known sliding rail device, is to improve the device so as to give it a greater tearapart strength, and greater stability of shape in the presence of downward loads, but without increasing the thickness of the metal strip from which it is made. The new sliding rail device is more elongated in the vertical direction and is consequently stronger, in particular for taking the stresses applied by a safety belt attached to the seat at the door side of the seat.

The problem is solved, according to the invention, in that at least one arm of each rail terminates, as seen in cross section, in an envelopment flange which is angled inwards to form a hook; at least one envelopment flange of at least one of the rails penetrating inwards into the hook region formed between the envelopment flange and the arm of the other rail; the envelopment flange of at least one rail working in contact with a guide member. In a vehicle equipped with this new sliding rail device the base of the U, as seen in the cross section, is attached to a substantially vertical member of the vehicle.

In spite of its simple construction, the new sliding rail device has sufficient tear-apart strength without being much heavier than the prior art device and without it being necessary to use thicker strip in its manufacture. The new device is installed in the vehicle so that it is higher than it is wide and consequently it is able to take both downwards and upwards stresses better than the known device, the one rail being attached to the seat, the other to the frame of the vehicle. A point to observe is that in the prior art device the tendency of the two rails to get torn apart is increased by the flexing of the arms of the cross section. In contrast to this, in the new device separation of the two rails from each other requires a major plastic deformation of the hooklike configurations.A further advantage of the present invention is that the guiding members, which can, for example, be guide-balls or guide sliders, are housed within the cross section of the rails, where they are well protected from dirt.

Tear-apart strength is increased, according to the invention, in that the envelopment regions of the two rails engage with each other hookwise, forming terminal flanges which are perpendicular to the bases. This configuration provides positive security against tearing apart of the rails and, as a further advantage, provides good accommodation for the guide-members, such as balls or slider pads. The new sliding rail device is preferably installed in the vehicle so that the base of the Ucross section of each rail is vertical.This not only gives a rail whose cross section is higher than it is wide, resulting in good tear-apart strength against vertically applied loads, but also ensures that the guiding grooves support the balls, assuming that these are used, in a plane perpendicular to the applied stress, i.e. the supporting surface for the ball is perpendicular to the applied stress, rather than nearly parallel to it, as in the prior art. The ball therefore has less tendency to jump out of the guiding groove.

A great advantage is obtained in that the two rails have essentially the same cross sections, apart from differences made necessary to accommodate the guide members. This advantage, which the invention makes possible, reduces manufacturing costs in that only one pressing tool is required for making both the rails.

In particular, the same guiding grooves can be formed in the arms or envelopment flanges of both the rails, but not both containing guide-members, such as balls, i.e. the guiding groove of the one rail remains empty. By this artifice the cross sections of the two rails can be exactly the same as each other, even though the supporting of the two balls differs.

Further characteristics and advantages of the invention can be derived from the remaining claims and from the more detailed description which will now follow of several examples, and with the help of the drawing, in which: Figure 1 is a cross section of a sliding rail device which is symmetrical about its horizontal central axis, i.e. the upper half is a mirror image of the lower half. An outer rail envelops an inner rail at two locations by means of horizontal envelopment flanges.

Figure 2 shows a somewhat similar arrangement, but the envelopment flanges slope at 450, relative to the horizontal.

Figure 3 shows a third version of the invention.

Figure 4 is a cross section of a sliding rail device in which the upper and lower guiding regions differ from each other.

Figure 5 shows an example in which the two rails are the same as each other, and with guidesliders and an internal roller.

Figure 6 shows an example in which the two rails are nearly the same as each other.

Figure 7 is a space-view of the rails device of Figure 3, but in this case equipped with a locking device.

The sliding rail device of the invention, as shown in the figures, comprises two rails 20, 21, each formed in one piece from sheet metal strip and enclosing between them guide-members 22 such as guide-balls 22'. Each rail 20,21, as seen in cross-section, comprises a substantially Ushaped portion 23 consisting of an elongated base 24 and two shorter arms 25. The base 24 which is flat, preferably extends vertically, when the device is installed in the vehicle, the arms 25 extending, in general, at 900 to the base 24. In the examples of Figures 1, 2 and 3 each arm 25 of the outer rail 20 has a bend so that the arm 25 forms a V-groove to accommodate a guide-ball 22'.

Nevertheless, even in these examples each arm 25 does extend, regarded as a whole, substantially perpendicular to the base 24. As each arm 25 is shorter than the base 25, as seen in cross section, a substantially rectangular configuration is obtained which is elongated vertically, the resulting structure being therefore well suited for taking the pull of a safety belt.

The bases 24 of the two rails 20, 21 extend parallel to each other, as seen in cross section. The arms 25 of the outer rail 20 (in the examples of Figures 1,2 and 3) overlap over the arms 25 of the inner rail 21, so that the two rails 20, 21 enclose between them an inner chamber 27 which is substantially rectangular in cross section.

The inner chamber 27 is large enough to accommodate the heads of two screws of type DIN M8 or MlO, without interference, the screws projecting outwards through bores 28 in the middles of the two bases 24 (compare Figure 1).

The screws serve for attaching the rails to a substantially vertical member (tunnel or door frame) of the vehicle.

In Figures 1,2,3,5 and 6 each arm 25 of each rail 20, 21 terminates in an envelopment flange 29 which is angled, with respect to the arm 25, so as to form a hook-like structure, generally indicated at 30. In Figure 4, on the other hand, only the upper arm 25 of each rail is arranged in this way.

In Figure 1 the envelopment flange 29 of the outer rail 20 is angled right back to make a 900 angle with respect to the base 24. On the other hand, the envelopment flange 29 of the inner rail 21 is angled back to form an L-shaped structure which engages in the hook formed by the envelopment flange 29 of the outer rail 20. It will be observed that the envelopment flanges all extend horizontally.

Still referring to Figure 1, it will be seen that between the envelopment flange 29 of the outer rail 20 and the adjacent surfaces of the inner rail 21 there are sufficient clearances (at 31') to ensure free sliding of the rails 20, 21. And it will be seen that in Figures 1,2 and 3 the entire system, as seen in cross section, is symmetrical about its central horizontal axis, i.e. the upper half is a mirror image of the lower half.

Referring now to Figure 2, in this example the envelopment flanges 29 of the outer rail 20 are comparatively short and form angles of only about 450 with the base 24 of the rail. Starting from the base 24, each envelopment flange 29 at first curves inwards, as seen in cross section, to form a guiding groove 26 for accommodating a guideball 22', and finally curves inwards still more to form the envelopment flange 29, which engages at 30 behind the envelopment flange 29 of the inner rail 21, but leaving sufficient clearance for free sliding movement.

The example shown in Figure 3 is even simpler.

In this case the envelopment flange 29 of the outer rail 20 extends parallel to the base 24 of the rail, engaging in the region 30 over the envelopment flange 29 of the inner rail 21. The envelopment flange 29 of the inner rail is substantially L-shaped in cross section, extending first parallel to the base 24 of the rail, and then extending perpendicular to the base 24 so as to form a guiding groove 26. A good envelopment is obtained in that the envelopment flange 29 of the outer rail extends to near the arm 25 of the inner rail 21, although still leaving sufficient clearance for free sliding movement. Thus the outer rail 20 is substantially C-shaped in cross section.

In contrast to the examples described above, the example of Figure 4 is not symmetrical about a central horizontal axis. The lower portion of the cross section is very simple in configuration, consisting only of two arms 25 with no envelopment flanges 29. The structure here agrees with the arrangement which is regarded as already known. If one were to form a cross section by reproducing this lower portion as a mirror image above a central horizontal axis, one would have the sliding rail device of the prior art. But in the example of Figure 4 the two rails 20, 21 differ in their upper portions. The upper portion of each rail 20, 21 has an arm 25 terminating in an Lshaped envelopment flange 29 whose outer end forms a guiding groove 26.Each envelopment flange 29 is angled around to form an envelopment hook 30 comprising a portion of the arm 25 and the L-shaped envelopment flange 29.

There is thus formed a system of two hooks which engage with each other by hook-ends which extend perpendicular to the bases 24. This greatly preferred sliding rail system is installed in the motor vehicle in such a position that most of the load is applied to the upper portion of the cross section, and so that the lower portion, which has a lesser tear-apart strength, is not so highly stressed.

The examples of Figures 5 and 6 are shown with rollers 31 in the inner chamber 27, for taking high downward loads. But the rollers 31 need not necessarily be provided. For most applications it is sufficient to provide, as in the examples described further above, only two guide-balls 22', or the like, where the arms 25 are angled around to form the envelopment hooks 30.

Referring now to Figure 5, the upper portion of the cross section here agrees essentially with the upper portion of the example of Figure 4. Here again the envelopment flanges 29 are L-shaped.

The arm 25 of the upper portion of the left-hand rail 21 is extended to form an envelopment flange 29 extending, at first, parallel to the base 24 and then curling inwards to terminate perpendicular to the base 24. This forms a U-shaped hook whose opening is towards the left. The upper arm 25 of the right-hand rail extends at first inwards, then upwards, then outwards to form an S-shaped hook in the region 30, whose opening is towards the right. The two hooks interlock each other. The lower portion of the cross section is arranged similarly. But whereas in the upper portion of the cross section the left-hand rail 21 forms the envelopment structure, in the lower portion this is done by the right-hand rail 20. In this example the guide-members are guide-shoes 22", such as those known from the German Offenlegungsschrift 27 02 576.It should be observed that only two guide shoes 22" are necessary, the one in the upper, the other in the lower portion of the cross section, because each guide shoe 22" is located in position by the other.

Each guide shoe 22" envelops the end-flange of the adjacent envelopment flange 29. It should be observed that the one rail 21 supports one of the guide shoes 22", the other rail 20 supporting the second guide shoe 22". The principle can, if desired, be applied to form various other cross sections. The example shown in Figure 5 contains a roller 31 in the inner chamber 27. The roller is held in place by a retainer 32.

The example of Figure 6 is essentially similar, but the guide-members here are balls 22' which roll guided in guide-grooves 26. In the upper portion of the cross section the guide-ball 22' rolls in guide-grooves 26 situated between the arm 25 of the left-hand rail 21 and the L-shaped envelopment flange 29 of the right-hand rail 20.

Other arrangements can be used, if desired, based on the same principles. A modification can, for example, become necessary if the roller 31 is omitted. With advantage there can also be a guide-groove 26 for balls 22' in the arm 25 of the right-hand rail 20 and in the L-shaped envelopment flange 29 of the left-hand rail 21, but without a guide-ball 22'. The purpose of this arrangement is to make the two rails 20,21 exactly the same as each other. This is not strictly true of the cross section shown in Figure 6, in contrast to what is shown in Figures 4 and 5. Here a roller 31 is contained in the inner chamber 27, the roller 31 having an annular groove 33. The roller 31 is guided, in the lower portion of the cross section, by a convex rib 34 formed by the upper surface of the groove 26, which is thus utilised twice.If the arm 25 of the right-hand rail 20 also had (as is not shown in the drawing) an empty guide-groove 26, the roller 31 would be guided in the upper portion of the cross section as well.

The example of Figure 6 has a very high tearapart strength, slides well and is simple to manufacture because the two rails are at least nearly the same as each other in cross section, so that the same type of strip can be used for both.

The rollers 31 are well guided and consequently can have small dimensions, leaving plenty of room, to right and left, for the screw heads.

Considering now the cross sections as a whole, in all the examples shown the hook structures 30 are situated well clear of the bases 24, i.e. each hook structure 30 is staggered in position parallel inwards by at least one strip thickness.

Referring now to Figure 7, this space-view shows the cross section of Figure 3, but equipped with an anti-slide lock 35. The terminal edge of the envelopment flange 29 of the right-hand rail 20 has equally spaced notches 36 and the upper arm 25 of the left-hand rail 31, including its envelopment flange 29, has a sheared-out slot 37 through which passes an L-shaped locking tooth 39. The sliding rails of the invention are well suited to accommodate an anti-slide lock of this kind and it will be seen that the lock is easily accommodated mainly in the interior of the inner chamber 27. The lock is very simple in construction.

An advantage of the sliding rail device of the present invention, in the versions shown in Figures 4 to 6, is that the inner chamber 27 is limited at the top by an arm 25 of the one rail and, at the bottom, by an arm 25 of the other rail. This allows a roller 31 to work between the two rails. In the symmetrical versions of Figures 1 to 3, on the other hand, a roller cannot be so easily accommodated. If it is desired to provide for high downward loads, this can nevertheless be done by using double guide-balls, rollers, diabolos or the like in the lower portion of the cross section. This does, of course, deprive these cross sections of their mirror-image symmetry. In the version of Figure 1 the two balls can, for example, be accommodated next to each other in the horizontal end-portion of the lower envelopment flange 29.The two balls 22' can conveniently roll on inclined surfaces of the arm 25 of the outer rail 20, leaving plenty of free space below to serve as a gutter for deposited dirt. The versions of Figures 2 and 3 can also easily be modified, on the same lines, to take double balls or roller bearings.

Moreover it will be noted that in the rails 20 or 21 of the various embodiments, the enveloping hook structures 30, viewed in cross-section end in terminal portions which are curved through at least 1 800 relative to the bases 24. Indeed this angle is about 1800 for the rail 20 in the embodiment of Figures 3 and 7; about 2250 in the case of the rail 20 of the embodiment of Figure 2; and about 2700 in the case of the rail 20 of the embodiments of Figure 1, and of the rail 21 in Figure 4. The outer enveloping hooks 30 of the embodiments of Figures 5 and 6 also have terminal portions curves through about 2700 relative to the straight base portions in both rails 20and21.

Claims

1. Sliding rail device, particularly for use in adjusting motor-vehicle seats in position longitudinally, the device comprising two rails, one of which slides along the other, guided by guiding means; each rail being essentially U-shaped in cross section and comprising, as seen in cross section, an elongated base and two shorter arms; the bases of the two rails extending parallel to each other; the two U's of the cross section facing each other; the arms of the one rail overlapping the arms of the other, so that an inner chamber is formed, characterised in that at least one arm (25) of each rail (20, 21) terminates, as seen in cross section, in an envelopment flange (29) which is angled inwards to form a hook; at least one envelopment flange (29) of at least one of the rails (20, 21) penetrating inwards into the hook region (30) formed between the envelopment flange (29) and the arm (25) of the other rail (20, 21); the envelopment flange (29) of at least one rail (20,21) working in contact with a guide-member (22).

2. Sliding rail device as claimed in Claim 1, characterised in that the envelopment flanges (29) of the two rails engage with each other hookwise in the regions (30), the envelopment flanges (29) extending, in this region, perpendicular to the bases (24).

3. Sliding rail device as claimed in Claims 1 or 2, characterised in that of the two rails (20, 21-), each has two hook regions (30) where its envelopment flange engages with that of the other rail.

4. Sliding rail device as claimed in Claims 1 or 2, characterised in that each rail (20, 21) has only one hook region (30) where the envelopment flanges of the two rails engage with each other.

5. Sliding rail device as claimed in one of the Claims 1 to 4, characterised in that the hook regions (30) are U-shaped in cross section and are situated alternately on either side of the arm (25).

6. Sliding rail device as claimed in one of the Claims 1 to 5, characterised in that the two rails (20, 21) have essentially the same cross sections, apart from differences made necessary to accommodate the guide-members (22).

7. Sliding rail device as claimed in one of the Claims 1 to 6, characterised in that the inner chamber (27) is large enough to accommodate, without interference, the heads of two screws of type DIN M8 or Ml 0 facing in opposite directions, the base (24) of each rail having an opening (28) through which the-body of the screw can pass.

8. Sliding rail device as claimed in one of the Claims 1 to 7, characterised in that the arm (25) of the rail, or the envelopment flange (29), is angled over to form a guiding groove (26) for guiding a guide member (22), particularly a guide-ball (22').

9. Sliding rail device as claimed in one of the Claims 1 to 8, characterised in that an arm (25) of a rail has a guiding groove (26) whose back forms a convex rib (34) for guiding a roller (31) situated in the inner chamber (27), the roller having a peripheral groove (33) which engages with the rib (34).

10. Sliding rail device as claimed in one of the Claims 1 to 9, characterised in that it has only two guide members (22), preferably balls (22'), working in the guiding grooves.

11. Motor vehicle equipped with at least one sliding rail device as claimed in one of the Claims 1 to 10, characterised in that the base (24) is attached to a substantially vertical member of the vehicle.

12. Motor vehicle as claimed in Claim 11, characterised in that the guide members are positioned the one vertically above the other.

13. Motor vehicle as claimed in Claims 11 or 12, characterised in that the sliding rail device is attached to a vertical portion of the door structure, such as a door post.

14. Motor vehicle as claimed in one of the Claims 11 to 13, characterised in that the sliding rail device has an attachment point for a seat belt.