GB2286522A - Vehicle seat slide with memory lock - Google Patents

Abstract

A seat adjustment slide for vehicle seating which provides a mechanical memory device to return the seat to an original position after the use of an easy entry system providing throw forward action of the seat to allow passengers access to rear seating. The slide incorporates a second 'memory' channel 250 mounted within the lower rail 112 of the dual rail slide, and a memory device 202 which can be engaged within the second channel at a predetermined position. Forward movement of the seat is allowed upon operation of the easy entry system without movement of the memory device. However, backward motion of memory device 202 beyond the memory device stop 106 is prevented. A standard seat adjustment handle is provided for normal adjustment of the seat position. The slide need be no larger than prior art slides since the additional locking mechanism required is entirely contained within the dual rails of a prior art design of slide. The normal adjustment catch formations and catch member are not shown, but may be in the form of notches on the bottom edge of the turned over flanges of bottom rail 112, which engage with a suitable catch - see prior art Fig. 3 (not shown). <IMAGE>

Description

SEAT ADJUSTMENT SLIDE The present invention relates to adjustment slides for allowing movement of, for example, vehicle seating.

Typically, vehicles are provided with a number of adjustment mechanisms for permitting various types of movement of a vehicle seat.

Forward and rearward motion of the seat is usually provided by way of a slide mechanism which comprises a lower rail fixed to the vehicle body, and an upper rail fixed to the seat, the rails being in sliding engagement with one another. The rails will include a detent mechanism for locking the seat into a selected longitudinal position.

In vehicles such as cars with two doors, it is often desirable to allow access to rear seats by tipping the front seats forward. This may be achieved simply by allowing the seat back to tip forwards. Preferably, however, an "easy entry system" also allows the seat to slide forwards at the same time, thereby providing maximum accessibility to the rear of the vehicle.

A problem with such easy access systems is that the original longitudinal position of the front seat is lost during this slide forward operation, resulting in the occupant of the front seat needing to readjust the seat every time a person gets into or out of the back of the vehicle.

A number of prior art easy entry systems have addressed this problem by providing a memory position so that the seat returns to its original position after sliding forward. However, these systems are all disadvantaged by being either expensive or bulky and complex to manufacture. Typically, electrically adjusted seating can provide this memory system using electronic control, but is expensive to produce and install. Known mechanical systems have typically required complex additional hardware added onto the slide mechanism, making them less compact and more expensive to produce.

It is an object of the present invention to provide a simple seat slide mechanism which provides a mechanically implemented memory position.

It is a further object of the present invention to provide such a mechanism as compact and cost effective as possible.

According to the present invention there is provided a seat adjustment slide comprising: a lower rail; an upper rail in sliding engagement with the lower rail, the lower and upper rails defining a cavity therebetween; stop means, located within the cavity, preventing relative longitudinal movement between the lower and upper rails past a memory position; and release means adapted to enable repositioning of the stop means within the cavity to modify the memory position.

The present invention will now be described in detail, by way of example, and with reference to the accompanying drawings in which: Figure 1 shows a front end view of a typical prior art seating slide suitable for adaptation to the present invention; Figure 2 shows a partial side view of the prior art slide of figure 1; Figure 3 shows a partial cross-sectional side view of the slide of figure 1 on line A-A; Figure 4 shows an exploded perspective view of selected parts of a slide according to the present invention; Figure 5 shows a front end view of an assembled slide according to the present invention; Figure 6 shows a partial side view of the slide of figure 5; Figure 7 shows an exploded perspective view of an alternative embodiment of a memory device for use in the slide of figure 4; and Figure 8 shows a perspective view of an arrangement of actuating levers suitable for use with the embodiment of figure 4.

With reference to figures 1 to 3 there is shown a typical prior art vehicle seat adjustment slide 10. The slide comprises a lower rail 12 in the form of a channel having a base 13 and upstanding side walls 14,15. At the upper extent of the side walls 14,15, they are each turned over to form an upwardly facing convex ridge 16,17 extending the length of the rail 12. Adjacent to each convex ridge a downwardly turned edge 18,19 is formed. An upper rail 30 resides over the lower rail, in the form of an inverted channel having downwardly extending sidewalls 31,32 each of which terminate in a re-entrant edge 33,34.

The lower rail 12 includes a number of threaded bolts 20 extending from the lower surface of the rail to provide fixing points to the floor of the vehicle in which the seat is to be installed. The upper rail 30 similarly includes a number of threaded bolts 35 extending upwardly from the upper surface of the rail to provide fixing points to the seat. Alternative forms of fixing mechanisms are commonplace in the art.

The upper and lower rails 30,12 are held apart in sliding engagement by means of a number of longitudinally spaced rollers 40,41. These rollers are retained longitudinally in relation to the upper rail 30 by a suitable retention means, for example, a loose fitting axle 43 coupled to the upper rail, or alternatively a cage (not shown) to enclose each roller. Lateral movement of the rollers can generally be prevented by suitable geometry of the roller in conjunction with the upwardly facing convex ridge 16,17 upon which it rides.

An adjustment mechanism for locking the two rails in one position is provided by a series of notches 50 in the downwardly turned edge 18 (best seen in figure 3).

On the sidewall 31 of upper rail 30 a sliding block 51 is mounted, which is capable of movement in the vertical direction, and is attached to the upper rail by way of a spring member having extending arms 52,53 which are coupled to upper channel 30 by way of a platform 54. The spring member arms 52,53 are each turned inward, passing through the sliding block 51 through aperture 55 and also through aperture 58 in the channel sidewall 31.

Each inner portion 56,57 of the spring member arms 52,53 passes under and engages with a corresponding notch 50 when the block 51 is in a biassed up position, by the spring arms 52,53. Inner portions 56,57 both turn and meet each other longitudinally adjacent to reentrant edge 34 (figure 1). To displace the block 51 downwardly in order to disengage the spring inner portions 56,57 from their respective notches, a lever 60 is provided which is pivoted about spigot 61 (figure 2) and biassed against spigot 62 (figure 2). Lever 60 is typically operable from below the front of the seat.

This arrangement can provide a primary forwards / backwards adjustment mechanism for the seat by operation of the lever 60. In an easy entry system, this slide mechanism may include a spring bias (not shown) in order that, upon release of spring inner portions 56,57 from notches 50, the seat will be thrown forward on the slide 10 by means of the spring bias. The operation of the easy entry system will typically provide simultaneous operation of the lever 60 automatically with release of the seat back in order that the seat back will tilt forward at the same time as the seat as a whole slides forward.

As has been previously discussed, the disadvantage with this system is that the seat must then be reset to the desired position by the occupant of the seat operating the lever 60 or other suitable mechanism.

In order to provide a mechanical "memory device" to return to the seat to its original longitudinal position, a number of schemes have been proposed in the art. Typically these include adding substantial and complex hardware onto the seat slides and seat.

In particular, one prior art device comprises two slides of the type described with reference to figures 1 to 3, axially aligned and mounted one on top of the other. One of the slide pair effectively provides the normal primary adjustment of the seat position as already described. The other slide in the pair may be a two-position type having a single forward and single backward extent, which is operated by the easy entry system.

According to the present invention, it has been recognized that a mechanical memory mechanism can be installed into a cavity 65 which exists between the upper and lower rails 30,12. An actuating lever is the only additional equipment which need be situated externally to the slide.

Additionally, this memory mechanism can be installed into some existing prior art designs of slides, such as that described with reference to figures 1 to 3, with only minimal redesign being necessary.

With reference to figures 4 to 6, a presently preferred embodiment of the invention is described. Where features of this embodiment have similar function to that which has been described in relation to the prior art, the same reference numerals have been used.

Referring now to figure 4 an exploded perspective view of selected components of the presently preferred embodiment is shown. An upper rail 130 has similar profile to the rail 30 of the prior art, but includes an access aperture 105 for allowing control of a memory device 200. A pair of holes or slots 158 is provided in one or both sides of the rail to allow access to an engagement mechanism similar in operation to spring inner portions 56,57 and notches 50, as described with reference to the prior art figure 1.

Lower rail 112 is similar to rail 12 of the prior art and also shown are bevel shaped roller buffers 170 which provide end stops for the forward and backward travel of the upper rail 130 relative to the lower rail 112. Typically, in an operation of the easy entry system, the upper rail 130 is released from engagement with the lower rail 112 in a manner as described with reference to figures 1 to 3, and a spring bias thrusts it forward until each pair of rollers 40,41 collides with respective rear-facing buffers 170.

A memory channel 250 is mounted within the channel 165 formed by lower rail 112. This may be attached to the lower rail 112 by rivetting, welding or bolting, for example through holes 251,252. The memory channel 250 includes a plurality of oppositely disposed holes 255,256 in each channel wall 253,254.

Memory device 200 comprises a housing 210 with a pair of oppositely disposed locking pins 201,202 extending laterally outwards therefrom. The locking pins are normally biassed toward an extended position, but upon operation of a plunger 203, the locking pins are withdrawn into the housing 210 of the memory device 200. An exemplary mechanism for this will later be described with reference to figures 5 and 6 and an alternative embodiment described with reference to figure 7. The memory device 200 resides within the memory channel 250, and is permitted to slide longitudinally therein when the plunger 203 is depressed, and the locking pins 201,202 thereby withdrawn into the housing 210. When locking pins 201,202 are in an extended position, they engage with a respective opposite pair of holes 255,256, thereby disabling longitudinal movement of the device 200.

In order to prevent rearward longitudinal movement of the upper rail 130 past a point determined by the position of the memory device 200, there is provided a downwardly projecting lug 106 (shown in dotted outline) forwardly mounted of the access aperture 105. In practice, the lug 106 may be formed by bending downward the cut out portion which creates aperture 105, or it may be welded to the underside of rail 130 in known manner.

With reference to figures 5 and 6, further detail of the assembled rail and memory device will be described. Figure 5 shows a front end view of the assembled slide 100. The bevelled roller buffers 170 and downwardly projecting lug 106 (figure 4) have been omitted from this diagram in order not to obscure the other parts of the mechanism.

Parts of the mechanism having identical functions to that described in respect of figures 1 to 3 are numbered correspondingly, and will not be described further at this stage. Memory channel 250 resides in the channel 165 formed by lower rail 112. Memory device 200 resides within the memory channel 250, and is shown with locking pins 201, 202 extending laterally outwards through holes in the memory channel 250. The locking pins 201,202 are mutually biassed outwards by way of spring 205, but prevented from further outward movement by the bevelled lower surface of plunger 203.

Downward movement of plunger 203 imparts an inward motion to the locking pins 201,202 by way of the bevelled surfaces, and thus causes retraction of the locking pins 201,202 from holes 255,256 in the memory channel (see figure 4).

Plunger 203 includes a top surface having a slot 207 or other suitable recess incorporated therein (best seen in figures 4 and 6). A release bar 220 is provided above the upper rail 130, typically pivoted about a convenient position on either the seat or upper rail itself, which enables a user to lower the engagement portion 221 of the bar 220 into the slot 207 thereby both depressing plunger 203 to allow retraction of the locking pins, and ensuring that the memory device 200 moves both forwards and backwards longitudinally within the memory channel 250 in concert with the upper rail 130 when the upper rail is moved. When the release bar is returned to a biassed upward position as shown in the figures, the memory device will no longer be capable of forward movement, and will only be capable of slight backward movement upon corresponding movement of upper rail 130 by virtue of the downwardly projecting lug 106 (figure 6) until the locking pins align with a pair of corresponding holes 255,256, at which point they will engage with memory channel 250.

Figure 6 shows a side view of the mechanism of figure 5, on section B-B, with a part of the memory channel wall 254 cut away to reveal detail of the memory device 200.

It will be understood that memory device 200 would preferably be constructed with a full housing 210 covering the front and back of the device.

In the figures no front wall has been included in order to show the inner mechanism. A number of other techniques well known in the art could readily be used for effecting an inward motion of oppositely disposed locking pins upon downward action of a plunger.

It will also be understood that the memory device mechanism need only provide a single outwardly disposed locking pin in order to function satisfactorily.

An alternative design of memory device 300 is shown in figure 7.

Locking pins 301,302 are inserted into a hole 313 in block 320. Each locking pin incorporates a bevelled aperture 311,312 which engages with one of the lower bevelled surfaces 314 of plunger 303. Plunger 303 incorporates a slotted hole 315 which has an extended diameter in a downward direction. Rod 316 passes through the block 320 via hole 317 and also through slotted hole 315, thereby retaining plunger 303 in the block while allowing upward and downward movement of the plunger. The device operates in analogous manner to the alternative embodiment already described.

Use of the slide will now be described with reference to figure 8, and to figures 5 to 7. For adjusting a normal seating position, the user will operate a first handle (not shown) which is connected to pivotted lever 330, to drive the lever 330 in a downward direction as indicated by arrow A. Lever 330 is connected to release bar 220, and pulls release bar 220 downwardly to: a) engage slot 307; b) depress plunger 303; and c) disengage locking pins 301,302 from memory channel 250 in manner analogous to that described in connection with figures 5 and 6. Downward movement of lever 330 is also communicated to sliding block 51 which disengage spring inner portions 56,57 from respective notches 50 in lower rail 112. The seat fixed to upper rail 130 is now completely free to move forwards and backwards to a new longitudinal position, carrying memory block 200,300 with it.

At the new position, the handle is released thereby causing upward movement of lever 330 opposite to the direction indicated by arrow A, thereby engaging spring inner portions 56,57 with a new set of notches 50, and locking pins 301,302 with a new pair of holes 255,256.

Upon operation of a second handle (not shown), lever 331 is actuated downwardly in the direction of arrow B, to effect the easy entry system. In this instance, only the sliding block 51 is depressed downwards to disengage spring inner portions 56,57 from notches 50. The coupling between lever 330 and sliding block 51 is such that downward movement of the block 51 does not cause corresponding downward movement of lever 330. When lever 331 is actuated, the upper rail (and seat) are then free to move forwards to the fullest extent of the slide where further movement is prevented by the bevelled roller buffers 170. The seat is then similarly returned to its starting position: backward movement past the starting position is prevented by collision of the downwardly projecting lug 106 with the memory device 200 or 300, thus restoring the original seat position. Upon release of the second handle, the inner portions 56,57 once again engage with the notches 50 and the seat is locked into position.

Claims (8)

1. A seat adjustment slide comprising: a lower rail; an upper rail in sliding engagement with the lower rail, the lower and upper rails defining a cavity therebetween; first engagement means adapted to lock the upper and lower rails together in a plurality of relative longitudinal positions; stop means, located within the cavity, preventing relative longitudinal movement between the lower and upper rails past a memory position; and release means adapted to enable repositioning of the stop means within the cavity to modify the memory position.

2. The seat adjustment slide according to claim 1 further including an inner rail coupled to, or formed integrally with, the lower rail, having a plurality of longitudinally spaced detents, the stop means including engagement means for engaging with the detents to lock the stop means at a memory position within the slide.

3. The seat adjustment slide according to claim 2 further including an aperture in the upper rail adapted to allow release of the engagement means therethrough to thereby adjust the memory position.

4. The seat adjustment slide according to claim 3 wherein the inner rail defines a memory channel in which the stop means may slide, and including a plurality of apertures in at least one side wall of the channel, the stop means including at least one outwardly extending locking pin, outwardly biassed to engage with a one of the plurality of apertures.

5. The seat adjustment slide according to claim 4 wherein the stop means includes a plunger coupled to cause the at least one locking pin to withdraw against the bias to a retracted position within the stop means.

6. The seat adjustment slide according to claim 3 wherein the stop means comprises a travelling block within the inner rail, the block including a slot on the upper surface thereof, and wherein the release means includes a protruding edge adapted to engage with the slot through the aperture in the upper rail thereby enabling longitudinal movement of the block in the inner channel by corresponding movement of the seat.

7. A seat adjustment slide substantially as described herein with reference to figures 4 to

8.