GB2366195A

GB2366195A - An automotive seat adjustment mechanism

Info

Publication number: GB2366195A
Application number: GB0021373A
Authority: GB
Inventors: Hugh Charles Christopher
Original assignee: Lear Corp
Current assignee: Lear Corp
Priority date: 2000-08-31
Filing date: 2000-08-31
Publication date: 2002-03-06
Also published as: GB0021373D0

Abstract

A vehicle seat 32 is mounted on a track 30. Drive means 10 includes a toothed gear ring 4 which engages with apertures 42 on the track. Rotation of the gear ring moves the seat back and forth along the track. Locking the gear ring prevents motion of the seat along the track. Lever 38 is coupled to an incremental drive mechanism and is normally biased towards a central locked position. Movement of the lever in directions I or J unlocks the gear ring for rotation in one direction and simultaneously moves the gear ring incrementally in that direction. Depression of button 40 unlocks the gear ring for free movement in either direction, allowing rapid seat adjustment. The incremental drive mechanism comprises two opposed locking pawls 22a/b acting on inner teeth of the gear ring and two opposed drive pawls 5a/b acting on outer teeth of the gear ring. Cams 3a/b couple the two sets of pawls and ensure that when one of the drive pawls engages with the outer teeth to rotate the gear ring in one direction, that the corresponding locking pawl is disengaged from the inner teeth to allow the rotation.

Description

<Desc/Clms Page number 1> AN AUTOMOTIVE SEAT ADJUSTMENT MECHANISM The present invention relates to an automotive seat adjustment mechanism and method. In particular it relates to a locking drive mechanism and method for adjusting specifically the fore and aft position of an automotive seat within a vehicle.

The fore and aft (longitudinal) position of the seat of a vehicle is generally adjustable in order to suit different occupants.

In a typical conventional arrangement the seat is slidably mounted to the vehicle floor via a pair of parallel fore and aft extending tracks attached to the floor. Cooperating track engaging features on the base of the seat slidably engage the tracks, and attach the seat to the vehicle floor whilst allowing the seat to slide in a fore and aft direction along the tracks. In order to secure the fore and aft position of the seat a locking means is provided to lock the relative position of the seat and tracks. Typically there are a series of apertures along the track and the locking means comprises a pin which selectively engages the apertures thereby locking the seat position. The pin is arranged and biased to engage the apertures within the tracks. An operating mechanism is also provided which is operable by the seat occupant to disengage the locking means and pin to allow relative sliding movement of the seat and tracks and thereby selectively allow the fore and aft position of the seat to be adjusted..

To make adjustment of the vehicle seat position easier a drive mechanism, operable by the seat occupant, may also be provided to move and slide the seat along the tracks when in an unlocked position. The locking means may also be incorporated within the drive mechanism. Such drive mechanisms are typically motorised. Whilst this provides easy operation such motorised drive mechanisms do add

complexity and cost.

Other suitable adjustment /mounting arrangements and locking drive mechanisms for adjusting and locking the fore and aft position of a vehicle seat are the subject of a large number of prior published patent specifications and proposed designs. This in part is indicative of the endless quest for improvements in such mechanisms in terms of efficacy, cost and suitability to a particular application or arrangement.

Various mechanical locking drive mechanisms are also known and used in a number of other applications both within the automotive field and generally. However locking drive mechanisms for use in providing a locking and adjustment drive for adjustable vehicle seats, and in particular the fore and aft position of the seat, present particular problems.

It will be readily appreciated that whilst a wide range of movement is desirable in order to accommodate different seat occupants, the position of the seat must be able to be securely and rigidly locked. In addition during a vehicle impact the seat is subject to considerable loads. The seat and any locking drive and adjustment mechanisms must be capable of withstanding such loads and therefore should be sufficiently robust. In terms of ease of use the drive mechanism must be straightforward and simple for an occupant to operate. Significantly the adjustment and drive mechanisms should allow for rapid movement over the range of adjustment whilst also allowing positioning in a multiplicity of different positions over the adjustmOnt range and secure locking of the desired position. In:,' addition cost is also significant consideration in@., the design of suitable locking drive mechanisms.

It is therefore desirable to provide an improved adjustment mechanisms for adjusting the fore and aft position of a vehicle seat, and in particular to provide an

improved locking drive mechanism for said seat adjustment which addresses the above described problems and/or which offers improvements generally.

According to a first aspect of the present invention there is provided an automotive seat adjustment mechanism and method of adjusting a seat position as defined in the accompanying claims.

In an embodiment of the invention there is provided an automotive seat adjustment mechanism for adjusting the fore and aft position of an automotive seat. The arrangement comprises a slidable seat mounting track for slidably mounting a seat to a vehicle floor, and a combined locking and drive mechanism including a drive gear ring which engages with cooperating features of the mounting track. The locking and drive mechanism comprises an incremental drive means, a drive actuation means, a locking means, and a locking actuation means. The incremental drive means is operated by the drive actuation means to operate the drive means to incrementally rotate the drive gear ring and move the seat in a fore and aft direction. The locking means is biased to normally lock the drive gear ring and so lock the fore and aft seat position. The locking actuation means is arranged to operate the locking means to allow the seat to freely slide.

The locking means may comprise at least one locking pawl which operatively engages a co-operating toothed profiled of the drive gear ring. Preferably there are a pair of locking pawls, with each of the locking pawls arranged to lock the drive ring against rotation in respective opposite directions. Furthermore the drive gear ring may be annular and has an internal toothed profile. The at least one locking pawl is then mounted within the annular drive gear ring and is arranged to engage the internal toothed profile of the drive gear ring.

Preferably the drive means comprises at least one drive pawl which is arranged to operatively engage a cooperating toothed profile of the drive gear to, in operation, rotate said drive gear ring. In particular the at least one drive pawl may comprise a pair of drive pawls, each of the drive pawls arranged to operatively engage and drive the drive ring in opposite respective directions. The at least one drive pawl is mounted externally to the drive gear ring and the at least one drive pawl is arranged to operatively engage an external toothed profile of the drive gear ring. Preferably the at least one drive pawl is mounted tangentially to the drive gear ring and is tangentially slidable to operatively engage the external toothed profile of the drive gear ring.

A selective release means may be operatively associated with the incremental drive means. The selective release means is arranged to selectively unlock the locking means to permit rotation of the drive gear ring in only the driven direction when the drive means is operated.

The embodiment also describes an automotive seat adjustment mechanism for adjusting the fore and aft position of an automotive seat comprising a slidable seat mounting track for slidably mounting a seat to the vehicle floor, and a combined locking and drive mechanism including a drive gear ring which engages with cooperating features of the mounting track. The combined locking and drive mechanism is arranged such that in a first mode of operation the mechanism incrementally and actively moves the seat in a fore or aft direction, whilst in a second mode of operation the mechanism is unlocked and the seat can freely slide.

Further the embodiment also describes a method of adjusting the fore and aft position of a vehicle seat using the described adjustment mechanism.

In a particular aspect the embodiment describes a method of adjusting the fore and aft position of a vehicle

seat which comprises a slidable seat mounting track for slidably mounting a seat to the vehicle floor, and a combined locking and drive mechanism including a drive gear ring which engages with cooperating features of the mounting track. The method comprising selectively operating the combined locking and drive mechanism in a number of modes. In a first normally biassed mode the combined locking and drive mechanism locks the rotational position of the drive gear ring such that the seat position is locked and fixed. In a second mode the combined locking and drive mechanism is operated to actively and incrementally rotate the drive gear ring to incrementally move and slide the seat and fore and aft seat position. In a third mode the combined locking and drive mechanism is operated to permit the seat to be caused to freely slide and the seat position freely moved.

The present invention will now be described by way of example only with reference to the following figures in which: Figure 1 is a schematic side view of a vehicle seat mounting and an automotive seat adjustment mechanism, according to the invention, for adjusting and locking the fore and aft position of the seat; Figure 2 is an illustrative more detailed view of the adjustment mechanism shown in figure 1 in its normally biassed locked condition; Figure 3 is a more detailed view of part of the adjustment mechanism in an operatively engaged ;activated drive condition.

Referring to figure 1 a vehicle seat 32 is slidably mounted to the floor 30 of the vehicle via a pair of parallel, fore and aft extending seat tracks 34 disposed on either lateral side of the seat 32. Cooperating track engaging slides 36 on the base of the seat 32 slidably

engage and abut against a slide surface of the tracks 34. The seat slides 36 and tracks 34 are arranged such that they are slidingly engaged, and therefore attach the seat 32 to the vehicle floor 30 whilst allowing the seat 32 to slide in a fore and aft (longitudinal) directions X,Y along the tracks 34. As such the slidable mounting arrangement of the seat 32 to the vehicle floor 30 is generally conventional.

The seat tracks 34 include a series of spaced apertures 42 disposed along the length of the track 34. A locking drive mechanism 10 is mounted on and to the seat 32. The locking drive mechanism 10 includes a toothed drive gear ring 4 which is rotatably mounted about a drive axis 1. The teeth of the drive ring 4 drivingly engage the cooperatingly arranged apertures 42 within the track 34. Accordingly rotation of the drive gear ring 4 drives, moves and slides the seat 32 in the fore and aft direction X,Y along the tracks 34. Similarly sliding movement of the seat 34 in the fore and aft direction causes rotation of the drive ring 4. Therefore locking the rotation and position of the drive ring 4, as will be explained later, locks the fore and aft position of the seat 32 along the tracks 34.

An operating lever 38, operable by the seat occupant extends from the drive mechanism 10. The operating lever 38 is pivotally mounted about axis 44 and can be moved upwards and downwards from its normal null horizontal position by the occupant, as shown by arrows H and I, to operate the drive mechanism. Movement of the lever 38 by the occupant selectively activates and operates the drive mechanism 10 to actively and positively rotate the drive gear 4 and slidingly move the seat 32 respectively and selectively in the fore and aft directions X,Y.

At the distal end of the lever 38 there is a locking button 40 which when pressed by the occupant is arranged to unlock the locking of the drive ring 4 allowing the seat 32 to be freely slid along the tracks 34 in the fore and aft

directions. When the locking button 40 is released by the occupant the drive ring 4 is locked and the fore and aft position of the seat 32 is again locked.

The lever 38 and locking button 40 accordingly provide a suitable actuation means for the occupant to selectively operate and actuate the drive mechanism 10 and control movement of the seat 32 position. It will be appreciated though that the lever 38 and locking button 40 could be replaced by other suitable operating arrangements to provide a means for the occupant to selectively operate the drive mechanism 10.

The locking drive mechanism 10 is shown in more detail in figures 2 and 3. The locking drive mechanism 10 includes an annular toothed drive gear ring 4 which is rotatably mounted about a main spigot member 9 to a fixed mounting plate 6 so that it is rotatable about a drive axis 1. The external circumference of the drive gear ring 4 has a toothed or gear profile 16. The external toothed profile 16 of the drive gear ring 4 engages with and cooperates with corresponding apertures 42 within the seat track 34. The series of apertures 42 form a ladder type arrangement along the seat track 34. It will be appreciated though that a cooperating gear profile, forming a rack, along the track 34 and which the drive gear ring 4 engages could alternatively be used instead of the apertures 42. In operation the drive gear ring 4 rotates in counter clockwise direction B or clockwise D direction thereby driving and sliding the seat 32 in a respective fore and aft direction X,Y.

The internal profile of drive gear ring 4 is also provided with a toothed or gear profile 18. A pair of internal locking pawls 2a,2b are mounted inside the drive gear ring 4 and are arranged to engage the internal toothed profile 16 of the drive gear ring 4. The locking pawls 2a,2b are pivotally mounted about pivot axes 26a,26b and mounting spigots 24a,24b to the mounting plate 6 and are located

within cutout sections of the main spigot member 9. The locking pawls 2a,2b are biassed by biassing means (not shown) such that the pawls 2a,2b are normally pivoted and urged into contact engagement with the internal toothed profile 18 of the drive gear wheel 4, as shown in figure 1. The locking pawls 2a,2b are respectively oppositely directed and located about the inside of the drive gear ring 4. The first locking pawl 2a is operatively arranged such that in the normally biassed engaged condition with the pawl 2a engaging the inner toothed profile 16 the locking pawl 2a prevents rotation of the drive gear ring 4in a first direction B, and as shown clockwise rotation of the drive gear ring 4. The second locking pawl ,-2b is oppositely arranged such that it operatively prevents the opposite rotation of the drive gear ring 4 in the other direction D, and as shown clockwise rotation of the drive gear wheel 4. In particular each of the locking pawls 2a,2b bears against opposite sides/faces of the teeth of the internal toothed profile 18 and the pawls 2a,2b are oppositely pivotally mounted.

In the normal (locked) condition and mode, as shown in figure 2, the drive gear ring 4 is rotatably locked against rotation in either direction, and the position of the drive gear ring 4 is secured by the two locking pawls 22a,22b. Accordingly the locking pawls 2a,2b, and their engagement with the toothed internal profile 18 of the drive gear ring 4, provide an operative means for locking and securing the drive gear ring 4 and its position. With the drive,gear ring 4 position locked, and rotation of the drive gear ring 4 prevented, the fore and aft position of the seat 32 is also locked. Accordingly locking of the drive mechanism 10, and specifically of the drive gear ring 4, effectively locks the fore and aft position of the seat 32.

A pair of external drive pawls 5a,5b are disposed outside of the drive gear ring 4. The external drive pawls

5a,5b are located on opposite respective sides of the drive gear ring 4. Each of the external pawls 2a,2b is slidably mounted on, and to, the mounting plate 6 via a respective mounting pin 12a,12b engaged within a cooperating slot 14a,14b in the mounting plate 6. The external pawls 5a,5b are disposed and operatively arranged to slide in a generally tangential direction on opposite sides of the outside of the drive gear ring 4.

In the normal condition and position shown in figure 1 the external pawls 5a,5b are disengaged from and clear of the toothed outer profile 16 of the drive gear ring 4. Suitable biassing means (not shown) maintain the external drive pawls 5a, 5b in this position. The slidable mounting of the external pawls 5a, 5b however allows each respective pawls 5a,5b to be operatively slid, as indicated by arrows A and C, tangentially relative to drive gear ring 4 and to engage the teeth of the outer profile 16 of the gear ring 4.

A release cam 3a,3b, comprising a shaped plate member, is connected to each of the external pawls 5a, 5b and is similarly arranged to slide generally tangentially with the movement of the respective external pawl 5a,5b. The release cams 3a, 3b extend towards the respective internal locking pawls 2a,2b. A release pin 22a,22b extends from each of the internal locking pawls 2a,2b. The release pins 22a,22b and an edge profile 28a,28b of the release cam 3a,3b are arranged such that as the release cam 3a, 3b is slid, the edge profile 28a,28b of the release cam 28a,28b abuts against and engages with the release pin 22a,22b. The release pin 22a,22b then slides over the edge profile 28a,28b. The shaped edge profile 28a,28b of the release cam 3a,3b and sliding movement urges the internal locking pawl 2a,2b to pivot radially inwards about its pivotal mounting 24a,24b and pivot axis 26a,26b, as shown by arrow F. As a result the internal locking pawl 2a,2b is disengaged from locking engagement with the internal toothed profile 18 of

the drive gear ring 4.

Accordingly as the external pawl 5a,5b is slid and moved this similarly moves the respective release cam 3a, 3b. Consequently as the external pawl 5a,5b engages the toothed external profile 16 there is substantially simultaneous disengagement of the respective locking pawl 2a,2b from the internal toothed profile 18. A more detailed illustration of the slid, engaged position of one of the release cams 3a and one external pawls 5a is shown in figure 2.

The operating lever 38 is operatively connected to external pawls 5a,5b via suitable linkages (not shown). The linkages and lever 38 are arranged such that when the lever 38 is operated it selectively operates one. of the respective external pawls 5a, 5b. In particular when the lever 38 is moved downwards I then external pawl 5b is selectively moved and the drive gear 4 rotated in the clockwise direction D so actively and positively driving the seat 32 in the forward direction X. Similarly moving the lever 38 upwards H moves the other external pawl 5a so actively driving and moving the seat 32 in the other, aft, direction Y.

In operation the mechanism 10 is suitably biassed such that it is normally in the locked condition and position as shown in figure 1. In this condition the drive gear ring 4 is locked by the internal pawls 2a, 2b and rotation of the drive gear ring 4, and so movement of the seat, is prevented.

Operation and movement of the lever 38 in a first way and sense, ie. downwards I by the user begins to operate and slide, as indicated by arrow A, one of the external pawls 5a into engagement with the external toothed profile 16 of the drive gear ring 4. Substantially simultaneously the release cam 3a associated with that external pawl Sa engages the release pin 22a of the internal locking pawl 2a and begins to disengage the respective locking pawl 2a. As a result the drive gear ring 4 is unlocked for rotation in the direction

B, in this case anticlockwise. Rotation of the drive ring 4 in the opposite direction D however is still prevented and the drive gear ring 4 is still locked against rotation in that direction D by the other locking pawl 2b which is still engaged. It should also be noted that even though internal locking pawl 2a is disengaged the drive gear ring 4 is not necessarily free to rotate in the anticlockwise direction B. The engagement of the external pawl 5a with the external toothed profile 16 will control such rotation.

Further operation and downwards movement I of the lever 38 further slides the external drive pawl 5a tangentially to the drive gear ring 4. This drives and rotates the drive gear ring 4 by an increment until the internal pawl 2a is in a position to re-engage the internal toothed profile 16 of the gear ring 4 at the next adjacent incremental position.

As the drive gear ring 4 is driven and rotated by the external pawl 5a the opposite internal locking pawl 2b is pivoted inwards against its biassing and jump one tooth of the internal profile 16. The arrangement of the opposite internal pawl 5b is such that it only locks and prevents rotation in the opposite clockwise direction D.

Upon subsequent release of, or movement of, the lever 38 to the null horizontal position, the external drive pawl 5a and release cam 3a are returned to there normal positions, as shown in figure 1, by the biassing of the mechanism 10. During the return movement the external pawl 5a pivots radially outwards, as indicated by arrow G and against the suitable biassing urging the external pawl 5a radially inwards, in order to jump and pass over the toothed external drive gear ring 4 profile 16. The lever 38 can then be operated and moved again and the above repeated in order to increment and rotate the drive gear ring 4 further in the clockwise direction and move the seat 32 in a forward direction X.

Operation of the lever 38 in the opposite sense and

direction, i.e. upwards H, slides and moves the opposite external pawl 5b and release cam 3b. This will similarly drive and increment the drive gear ring in the opposite, clockwise direction as indicated by arrow D. This thereby actively and positively slidingly drives the seta in an aft direction along the tracks 34.

In t;@is way, and by a user operating the operating lever, the drive gear ring 4 can be incrementally rotated with the mechanism 10 providing a rachet type, incremental, rotary drive of the drive gear ring 4. Therefore using this drive mechanism 10 in this mode of operation, the fore and aft position of the seat 32 can be accurately and actively moved by a user operating the lever 38 and drive mechanism 10.

The arrangement of the locking pawls 2a,2b and external drive pawls 5a,Sb also ensures that the seat 32 is securely driven and moved. In particular it ensures that the movement of the seat 32 is controlled and limited to that generated by operation of the drive mechanism 10 and operating lever 38.

In the normally biassed condition and mode the drive gear ring 4 is also locked in position by the locking pawls 2a,2b. In this way the drive gear ring 4 and the seat 32 are both securely locked in a number of different positions.

The locking button 40 is connected by suitable linkages (not shown) to both of the locking pawls 2a,2b. The linkages are arranged such that when the locking button is operated, both locking pawls 2a,2b simultaneously pivoted, radially inwards. Accordingly operation of the locking button 40 simultaneously unlocks both locking pawls 2a,2b from engagement with the internal toothed profile 18 of the drive ring 4. The drive ring 4 is therefore unlocked by actuation and operation of the locking button 40 and the drive ring 4 can then be freely rotated. In this way, and further mode of operation, the mechanism 10 can be in effect disengaged and

the seat 32 can be freely moved by the user, to any position. Such movement, since it is not incremental or actively controlled by the drive mechanism 10, may be much more rapid than the incremental drive provided by active operation of the drive the mechanism 10. Once moved to a desired position the locking button 40 released so that the internal pawls 2a,2b can then re-engage with the internal toothed profile 18 under their radially outward biassing, and the drive ring 4, mechanism 10 and seat 32 are then locked in the new position.

Overall therefore the mechanism 10 provides a drive means which when actuated by a user in a first mode of operation provides an active drive (in either direction) and movement of the driven member in small increments to a particular position. In a second mode of operation, by a user actuating the release actuation means the drive mechanism 10 allows the drive ring 4 and seat 32 to be passively moved to a desired position. The mechanism 10 also securely locks the drive ring 4 and seat 32 securely in position when in the desired position, and also during the active incremental driven mode of operation and movement of the drive ring 4 and seat 32.

It will be appreciated that there are a number of variations that can be made to the above described embodiments of the invention. In particular the drive mechanism 10 could be mounted to the floor 30 and the series of cooperating apertures 42 which the drive gear ring engages would then be disposed on the base of the seat 32, or on a suitable rail mounted thereon.

Claims

CLAIMS 1. An automotive seat adjustment mechanism for adjusting the fore and aft position of an automotive seat comprising:- a) a slidable seat mounting track for slidably mounting a seat to a vehicle floor, and b) a combined locking and drive mechanism including a drive gear ring which engages with cooperating features of the mounting track, the locking and drive mechanism comprising a incremental drive means operated by drive actuation means for operating the drive means to incrementally rotate the drive gear ring and move the seat in a fore and aft direction, a locking means biassed to normally lock the drive gear ring and so lock the fore and aft seat position, and locking actuation means for operating the locking means to allow the seat to freely slide.
2. An automotive seat adjustment mechanism as claimed in claim 1 in which the locking means comprises at least one locking pawl which operatively engages a cooperating toothed profiled of the drive gear ring.
3. An automotive seat adjustment mechanism as claimed in claim 2 in which the at least one locking pawl comprises a pair of locking pawls, each of the locking pawls arranged to lock the drive ring against rotation in respective opposite directions.
4. An automotive seat adjustment mechanism as claimed in claim 2 or 3 in which the drive gear ring is annular and has an internal toothed profile and the at least one locking pawl is mounted within the annular drive

<Desc/Clms Page number 15>

gear ring and is arranged to engage the internal toothed profile of the drive gear ring.
5. An automotive seat adjustment mechanism as claimed in any preceding claim in which the drive means comprises at least one drive pawl which is arranged to operatively engage a cooperating toothed profile of the drive gear to, in operation, rotate said drive gear ring.
6. An automotive seat adjustment mechanism as claimed in claim 5 in which the at least one drive pawl comprises a pair of drive pawls, each of the drive pawls arranged to operatively engage and drive the drive ring in opposite respective directions.
7. An automotive seat adjustment mechanism as claimed in claims 5 or 6 in which the at least one drive pawl is mounted externally to the drive gear ring and the at least one drive pawl is arranged to operatively engage an external toothed profile of the drive gear ring.
8. An automotive seat adjustment mechanism as claimed in claim 7 in which the at least one drive pawl is mounted tangentially to the drive gear ring and is tangentially slidable to operatively engage the external toothed profile of the drive gear ring.
9. An automotive seat adjustment mechanism as claimed in any preceding claim in which a selective release means is operatively associated with the incremental drive means, the selective release means arranged to selectively unlock the locking means to permit rotation of the drive gear ring in only the driven direction when the drive means is operated.

<Desc/Clms Page number 16>
10. An automotive seat adjustment mechanism for adjusting the fore and aft position of an automotive seat comprising:- a) a slidable seat mounting track for slidably mounting a seat to the vehicle floor, and b) a combined locking and drive mechanism including a drive gear ring which engages with cooperating features of the mounting track, characterised in that the combined locking and drive mechanism is arranged such that in a first mode of operation the mechanism incrementally and actively moves the seat in a fore or aft direction, whilst in a second mode of operation the mechanism is unlocked and the seat can freely slide.
11. An automotive seat adjustment mechanism as hereinbefore described with reference to figures 1 to 3.
12. A method of adjusting the fore and aft position of a vehicle seat which comprises:- a) a slidable seat mounting track for slidably mounting a seat to the vehicle floor, and b) a combined locking and drive mechanism including a drive gear ring which engages with cooperating features of the mounting track, the method comprising selectively operating the combined locking and drive mechanism in a number of modes, in which in a first normally biassed mode the combined locking and drive mechanism locks the rotational position of the drive gear ring such that the seat position is locked and fixed, in a second mode in which the combined locking and drive mechanism is operated to actively and incrementally rotate the drive gear ring to incrementally move and slide the seat and

<Desc/Clms Page number 17>

fore and aft seat position, and in a third mode in which the combined locking and drive mechanism is operated to permit the seat to be caused to freely slide and the seat position freely moved.
13. A method as claimed in claim 12 using an automotive seat adjustment mechanism of any one of claims 1 to 11.
14. A method of adjusting the fore and aft position of a vehicle seat using an automotive seat adjustment mechanism of any one of claims 1 to 11.
15. A method as hereinbefore described .with reference to figures 1 to 3.