GB2033738A - Improvements in or relating to vehicle seat slide mechanisms - Google Patents

Abstract

A mechanism which will enable a seat to be moved temporarily on its slide system (12, 13) from an initial position, and which is provided with a 'memory' device to enable the seat to be automatically returned to its initial position, including means (16) for locking the seat in a chosen operative or initial position, and drive means (30-33) movably mounted on a seat-carrying movable assembly carried on the seat slide system and operable to engage positively a fixed part (15) of the seat slide system thus to advance the movable assembly from the initial position and return the it to that position, the drive means also being arranged to release the locking means before moving the assembly, and to cause the locking means to re-engage on return of the assembly to the initial position. <IMAGE>

Description

SPECIFICATION Improvements in or relating to vehicle seat slide mechanisms This invention relates to a fore and aft position setting mechanism for a vehicle seat.

It is normal for the front seats of a passenger car, or other road vehicles to be mounted on slides by which the fore and aft position of the seat may be adjusted so that the driver may be correctly positioned relative to the controls of the vehicle. In many instances, particularly that of a passenger car having a "two door" arrangement, the front seats are arranged so that the seat backs may be folded forwards to allow access through the door to the rear of the vehicle and to a back seat of a vehicle if such is fitted.

In some cases it is desirable that a seat may be moved temporarily forwards on its slides to provide access, without necessarily tilting the seat back.

It is an object of the present invention to provide a mechanism which will enable a seat to be moved temporarily on its slide system from an initial position, and which is provided with a "memory" device to enable the seat to be automatically returned to its initial position.

Accordingly the present invention provides a vehicle seat support slide arrangement including means for locking the seat in a chosen operative or initial position, and drive means movably mounted on a movable assembly carried on the seat slide arrangement and operable to engage positively a fixed part of the seat slide arrangement thus to advance the seat from the initial position and return the seat to that position, the drive means also being arranged to release the locking means before moving the seat, and to cause the locking means to reengage on return of the seat to the initial position.

In one arrangement the drive means is arranged to engage in one of a series of notches formed along the fixed part of the slide system by means of a drive tooth. Preferably the drive tooth is carried on a pawl which is pivotally mounted at an end of a drive link which is in turn pivotally mounted on the moving assembly carried on the seat slide arrangement. Preferably the locking means also enages in a selected one of the same or a further series of notches formed along the fixed part of the slide system. Preferably the drive link is operatively connected to a foldable seat back forming part of the movable assembly to be movable therewith to advance the seat from the initial position on folding of the seat back.

In order to promote a fuller understanding of the above and other aspects of the present invention, two embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a schematic side elevation of a first embodiment of the invention, Figure 2 shows a plan view of the embodiment of Fig. 1, Figure 3 shows a schematic end view on the arrow Ill of Fig. 1, Figure 4 shows a schematic side elevation of a second embodiment of the invention, Figures 4A and 4B show detailed crosssections on the lines A-A and B-B of Fig. 4, Figure 5 shows a half plan view of the embodiment of Fig. 4, Figure 6 shows a schematic end view on the arrow VI of Fig. 4, and Figures 7, 8 and 9 show detail views of various components of the embodiment of Fig. 4.

Referring first to Figs. 1, 2 and 3, there is shown a vehicle seat slide assembly embodying the invention. The slide assembly comprises a pair of slide rail devices 10 and 11 each of which comprises a fixed portion 1 2 adapted to be fixed to the floor of a vehicle and a movable portion 1 3 arranged for the attachment and support of a vehicle seat. The slide members 1 2 and 1 3 are formed from sheet metal material and embody ball-bearing tracks in known manner per se so that the slide 1 3 can run in the slide 1 2 on ballbearings as indicated at 14 in Fig. 3.

The slide members 1 2 and 1 3 are each formed with a series of notches 1 5 disposed along each side thereof, as indicated in Fig. 2, and a main locking member 1 6 pivotally mounted about a pin 1 7 in the slide member 1 3 is provided with dogs 1 8 to engage in a slot 1 5 of the slide member 1 2 and of the slide member 1 3 when they are in a selected relative position with those slots in register, thus to lock the slide member 1 3 in any one of a plurality of slide positions along the member 12.

An operating lever 1 9 which is also pivotally mounted in each slide member 1 3 engages on an arm 20 of the respective locking member 1 6 so that pivoting of each operating member 1 9 lifts the dogs 1 8 of that locking member clear of the notches 1 5 for sliding movement. The operating membe-s 1 9 3re both resiliently biassed to a position to move the locking members 1 6 to an engaged position, by means of a spring 21.The operating members 1 9 of the slide on each side of the seat are inter-connected by a cross bar 22 which is provided with a handle 23 by which the two operating members 19, and thus the two locking members 1 6 of the two slides may be operated.

A seat structure which is not shown in detail, but a part of the sub-frame of which is shown in dotted outline in Fig. 1 at 24, is mounted on the two slide members 1 3. The structure 24 supports a seat portion of the vehicle seat and a pivbt axis indicated at 25.

The seat back portion is mounted on the structure 24 by means of brackets indicated in dotted outline at 26, disposed one on each side of the seat structure. The back portion of the seat is pivotal about an axis 27 on the brackets 26 for adjustment of the rake angle of the back relative to the seat portion, whereas the brackets26 together with the seat back portion are pivotal about the axis 25 so that the back can be folded forward for instance to allow access to the rear of a vehicle in which the seat is fitted.

A drive link 30 is pivotally mounted about the axis 25 on each side of the seat and angularly coupled to the respective bracket 26 so that it rotates about the axis 25 with the bracket. Each drive link 30 extends downwards and has a ratchet pawl 31 pivotally mounted at its lower end about an axis 32.

The ratchet pawl has a tooth 33 which is shaped to engage positively in the notches 1 5 formed in the associated slide member 1 2 but not to engage in the notches of the slide member 13. Each pawl 31 is resiliently biassed in an anti-clockwise direction, as seen in Fig. 1, by means of a spring 34 operative between it and the drive link 30, to cause the tooth 33 to engage in the notches 1 5.

The operating member 1 9 of each slide device is provided with an extension rod 35 extending back towards the drive link 30 and arranged so that it is engaged by ratchet pawl 31, as the drive link is moved from the normal position shown in Fig. 1 in an anticlockwise direction, thus to dis-engage the locking member dogs 18 from the notches 1 5 freeing the respective slide member 1 3 for movement in the associated slide member 1 2.

Thus in use of the device, when the seat back is pivoted about the axis 25 to be folded forward, the drive link 30 is moved in an anticlockwise direction, as seen in Fig. 1, with the consequence that the extension rod 35 is depressed by the ratchet pawl 31 to release the dogs 1 8 and thus to release the slide member 13 for movement in the slide member 12, while the tooth 33 is bought into engagement with that one of the slots 1 5 in the slide member 1 2 which is immediately adjacent the tooth 33 with the seat in its initial position in the slide members 12.Further folding movement of the seat back causes the drive link 30 to move further in an anti-clockwise direction thus driving the seat and the slide members 1 3 forwards, or to the left as seen in Fig. 1, in the slide members 1 2 by the engagement of a tooth 33 in the slots 1 5 as discussed above. Thus as the seat back is folded forwards, the main locking member 1 6 holding the seat in position on the slide member 1 2 is released and the seat is moved forward.During such movement the spring 34 keeps the tooth 33 in engagement with the selected one of slots 1 5. The positioning of the various items of this mechanism is such that one of the slots 1 5 always falls immediately below the tooth 33 when the dogs 1 8 are engaged in others of the slots 1 5.

When the seat back is pivoted back to its normal position, the drive link 30 is swung in a clockwise direction and this drives the seat back by means of the tooth 33 engaging in the same slot 1 5 in the slide member 12, to the initial position as indicated in Fig. 1, and at the same time the extension rod 35 is released allowing the dogs 1 8 to re-engage in the same slots 1 5 from which they were originally released.

Thus it can be seen that the mechanism provides for the movement of the seat forwards as the seat back is pivoted forward and its return to the initial position, giving the mechanism a "memory" facility.

Figs. 4, 5 and 6 show a second embodiment of the invention, and where parts have a similar function to those of the previous embodiments they are given the same reference number.

In this embodiment each drive link 30 which is angularly connected to the associated plate 26 by means of a dog 40 on the drive link 30 engaging in an aperture 41 in the plate 26, carries a roller 42 towards its lower end. An associated cam link 43 is pivotally mounted on the frame 24 about an axis 44 and is provided with an upper cam surface which is engaged by the roller 42. The free end of the link 43 is formed with an elongated aperture to receive the end 45 of the rod 35 connected to the operating member 1 9 the end of the rod 35 being angled to this purpose. The links 30 and 43, and the ratchet member 31 of this embodiment are shown in more detail in Figs. 8, 7 and 9 respectively.

The device operates substantially as the previous embodiment with the seat back being pivoted forwards about the axis 25.

Initially the drivelink 30 carries the roller 42 up a ramp 46 depressing the link 43 about the axis 44. This depresses the end 45 of the arm 35 thus releasing the locking member 18 ready for the seat to move forwards, and engages the tooth 33 of the ratchet member 31 in a respective notch 1 5 in the slide member 1 2. The positions assumed by the axis 32, the roller 42, and the end 45 of the arm 37, at this point in the operation are indicated in Fig. 4 by the references 32', 42' and 45'.

On further forward pivotal movement of the seat back about the axis 25, the seat moves forward through the engagement of the tooth 33 with the notch 1 5 and the pivotal movement of the drive link 30, while the roller 42 runs round the arcuate portion 47 on the link 43 maintaining the operating member 1 9 in the unlocked position for such movement. As the seat back is returned to its normal position, the reverse operation takes place in a manner exactly similar to that described with reference to the previous embodiment.

In this embodiment there is shown a catch 48 pivotally mounted on the frame 24 to lock over a pin 49 on the seat back portion to lock it in its normal position. Movement of the catch 48 may be interlocked with the ignition system of the car for safety purposes, so that the seat back may only be swung forward when the ignition is switched off.

Claims (9)

1. A vehicle seat support slide assembly having a first part to be fixedly mounted in a vehicle and a second part movable on the first to carry a seat, including means for releasably locking the second part and seat in a chosen operative or initial position on the first part and drive means movably mounted on the second part and operable to engage positively the first part so as to advance the seat on the first part from said initial position, said drive means also being arranged to release the locking means before moving the seat, and so as to return the seat to said initial position and cause the locking means to re-engage.

2. A vehicle seat support slide assembly as claimed in Claim 1, in which said first part is formed with a series of notches and said drive means includes a drive tooth arranged to engage in an appropriate one of said notches when the second part is in said initial position.

3. A vehicle seat support slide assembly as claimed in Claim 2, in which said drive means comprises a drive link pivotally mounted on said second part, and the drive tooth is carried on a pawl pivotally mounted on the drive link.

4. A vehicle seat support slide assembly as claimed in Claim 2 or 3, in which said locking means engages in a selected one of said notches to lock the second part in said initial position.

5. A vehicle seat support slide assembly as claimed in Claim 1, 2, 3 or 4 in which said locking means comprises a catch member pivotally mounted on said second part.

6. A vehicle seat support slide assembly as claimed in Claim 5 in which said catch member includes an extension lever, and said drive member is arranged to move that extension lever to release the locking means.

7. A vehicle seat support slide assembly as claimed in Claim 6, in which said drive member is provided with a roller arranged to engage and pivot a cam link which is pivotally mounted on said second part, and the cam link is arranged to move said extension lever to release the locking means.

8. A vehicle seat support slide assembly as claimed in any preceding claim in which a seat carried on said second part includes a pivotally mounted back portion, and said drive means is operatively connected with the seat back so that tilting the back forwards advances the seat from said initial position and vice-versa.

9. A vehicle seat support slide assembly substantially as herein described, with reference to the accompanying drawings.