GB2355399A

GB2355399A - Seat rail deformable under crash conditions

Info

Publication number: GB2355399A
Application number: GB9925123A
Authority: GB
Inventors: Ali Mirghashini
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 1999-10-22
Filing date: 1999-10-22
Publication date: 2001-04-25
Anticipated expiration: 2019-10-22
Also published as: GB9925123D0; GB2355399B

Abstract

A vehicle seat rail arrangement consists of a rail with a carriage mounted on the rail. The carriage is provided with at least one plunger 24 which is biased towards a locking position in which part of the plunger extends through an aperture 80 formed in part of the carriage 11 and into engagement with engagement means, such as the periphery of an aperture 84 formed in the rail 4 . Thus the carriage is locked to prevent axial movement along the rail. The part of the plunger 24 which extends through the aperture 80 in the carriage is provided with a peripheral groove 31 that presents a face 90 that extends generally perpendicularly to the axis of the plunger. The material forming at least the part of the carriage in which the aperture 80 is formed is deformable. If a substantial force is applied to the carriage then the material of the carriage will deform and engage the face 90 formed on the plunger 24 to prevent the plunger from moving towards a retracted position.

Description

2355399 PATENTS ACT 1977 P13777GB-NF/ec DESCRIPTION OF INVENTION

"IMPROVEMENTS IN RELATING TO A VEHICLE SEAT - RAIL ARRANGEMENT" THE PRESENT INVENTION relates to a vehicle seat rail arrangement and more particularly relates to a vehicle seat rail arrangement which enables the position of a seat within a vehicle to be adjusted axially of the vehicle and in which a locking mechanism is provided to lock the seat in position on the rail.

It has been proposed previously to provide a vehicle seat rail arrangement upon which a vehicle seat may be mounted to enable the vehicle seat to move axially of the vehicle. Thus the seat may be moved forwardly if the seat is to be occupied by a relatively short person or may be moved rearwardly if the seat is to be occupied by a relatively tall person. It is important that an adequate locking mechanism is provided which secures the seat fixedly to the rail in the selected position. It is, of course, particularly important that the seat should not move in an accident situation, and it is to be understood that in an accident situation a very substantial force may be applied to the seat.

2.

DE-A-19735030 discloses a vehicle seat rail arrangement in which a carriage, which supports the seat, and which is slidably mounted on a rail, is provided with a plurality of downwardly biased plungers. The plungers are adapted to co-operate with apertures forined in the rail to lock the carriage in position, and a mechanism is provided to lift the plungers out of the apertures when it is desired to move the seat axially of the vehicle. It has been found, however, that in an accident situation there is a tendency for the carriage to deform, lifting the plungers to a position in which they no longer engage the apertures in the rail. Thus, in an accident situation, the carriage may be released inadvertently, which is undesirable.

The present invention seeks to provide an improved rail arrangement for a vehicle seat.

According to this invention there is provided a vehicle seat rail arrangement, the arrangement comprising an elongate rail and a carriage mounted on the rail for axial movement along the rail, the carriage being provided with at least one plunger, the plunger being biased towards a locking position which part of the plunger extends through an aperture formed in part of the carriage and into engagement with engagement means provided on the rail to retain the carriage in a fixed position, means being provided to retract the plunger from the locking position to enable the carriage to be moved axially of the rail, the part of the plunger which extends through said aperture being formed with a formation that presents a face that extends generally perpendicularly to the axis of the plunger, the material forming at least the part of the carriage in which said aperture is formed being deformable so that if a substantial force is applied to the carriage the material will deform and engage the engagement face formed on the plunger to prevent the plunger from moving towards said retracted position.

3.

Preferably the formation is a groove formed in the periphery of the plunger.

Conveniently the groove has two opposed parallel sides which extend transversely to the axis of the plunger.

Preferably there plurality of plungers, the rail being provided with engagement means adapted to the engage at least some of the said plungers whenever the carriages in a selected one of a plurality of predetermined positions.

Advantageously means to retract the or each plunger from the locking position comprises a lifting comb, the lifting comb having a finger or fingers adapted to be adjacent the or each plunger, means being provided to move the lifting comb to bring the finger or fingers to engagement with an abutment on each plunger to lift the plunger against a spring bias.

The invention also relates to a vehicle seat rail as described in combination with a vehicle seat mounted on the carTiage.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIGURE I is an exploded view of a rail arrangement in accordance with the invention, 4.

FIGURE 2 is a fragmentary partial sectional view of the rail arrangement figure 1, FIGURE 3 is an enlarged view of part of figure 2 showing the rail arrangement in an ordinary situation and FIGURE 4 is a view corresponding to figure 3 showing the rail arrangement in an accident situation.

Referring initially to Figure 1 of the accompanying drawings a rail arrangement for a vehicle seat includes a rail 1. The rail I is extruded from an appropriate material and has a uniform cross section. The rail is provided with a plurality of apertures 2, spaced along the length of the rail, and the rail may be provided of a plurality of pop rivets 3. The pop rivets extend partly into the rail to retain a plurality of ball bearings that support a carriage (to be described below).

The rail incorporates a generally flat base 4 and two upstanding side walls 5, 6. The upstanding side walls terminate with flanges 7 and 8 which are generally inwardly directed.

The rail I co-operates with a carriage 10. The carriage 10 is mounted on the rail and is slidable axially of the rail. A plurality of ball bearings are located between the carriage 10 and the rail I to support the carriage for low friction movement. The carriage is adapted to support a vehicle seat, as is conventional. The carriage 10 may be formed of an extrusion of an appropriate material, and is of generally uniform cross section. The carriage has a central portion of generally rectangular form defining a horizontal base I I and, space therefrom, a horizontal upper part 12. Outwardly extending flanges 14, 15 are 5. provided on either side of the main part of the carriage 10, the flanges 14 15 co-operating with the flanges 7 and 8 as carried by the rail I I in order to retain the carriage 10 in position whilst enabling the carriage 10 to slide axially of the rail 1.

The upper part 12 of the carriage is provided with four evenly spaced apertures 20, 21, 22, 23 each of which is dimensioned to receive part of a respective plunger 24, 25, 26, 27 as can be seen more clearly in Figure 2. Each plunger, such as the plunger 24, comprises an upper portion 28 of relatively large diameter, that upper portion having a blind axial bore 29 extending downwardly from the upper surface thereof. The plunger has a lower portion 30 of smaller diameter. The outer wall of the lower portion 30 is provided with a surface formation in the form of an annular groove or recess 31 which, as will become clear from the following description, provides an engagement face which is directed generally transversely to the axis of the plunger. The groove has two opposed parallel sides that extend transversely to the axis of the plunger.

Each plunger 24, 25, 26, 27 is associated with a respective compression spring 32, 33, 34, 35, the lower part of the compression spring being received within the blind bore formed in the upper portion of the plunger. The compression springs 32 to 35 extend upwardly above the plungers 24 to 27.

A cover element 36 is provided which, in plan, is of generally "T"' shape. The stem 37 of the "T" is provided with an integrally formed hollow upstanding chamber 38, there being four downwardly extending dimples 39 formed on the upper wall of the chamber.

6.

The head, 40, of the "T" is provided with a rectangular slot 41 located in a line with the stem 37 of the "T" and extending transversally thereto, and the two ends of the head 40 of the "T" are provided with upstanding flanges 42, 43 each configured to accommodate an end portion of a bowden cable.

The cover element 36 is provided with apertures 44, 45 adapted to receive pop rivets 46, 47, to secure the cover 36 to the upper part 12 of the carriage 10, with the pop rivets 46, 47 also passing through apertures 48, 49 provided for that purpose in the upper part of the carriage 12. When the cover has been located in position the rectangular aperture 41 provided in the cover is aligned with a rectangular aperture 50 formed in the upper part of the carriage.

When the cover is in position, the upper end of each spring, such as spring 32 engages a dimple 39 as formed in the cover. The plunges 24, 25, 26, 27, are thus biased downwardly.

Located within the carriage is a lifting comb 51 and a lifting comb housing 52.

The lifting comb 51 is formed from a single metal plate and comprises a planar base portion having a plurality of fingers 52, 53, 54, 55. The planar portion is provided at on side with an upturned lip 56 for reinforcing purposes and, at each end, is provided with an upstanding lug 57, 58. The lugs are apertured, with square sectioned apertures 58, 59 to receive a square sectioned shaft 60 adapted to co-rotate with the comb 51. The shaft 60 extends beyond the ends of the comb 5 1, the protruding ends of the shaft receiving bearings 6 1, 62. One end of the shaft engages an aperture 63 provided in an actuating arm 64. The arm 64 extends through the co-aligned apertures 50 and 41 so that the 7. free end of the actuating arm 64 is located between the upstanding flanges 42, 43 provided on the cover element 36.

The lifting comb housing is accommodated in a comb housing 65 which is also formed from the single metal plate and has an upper surface 66 provided with apertures which correspond with the apertures provided in the upper part 12 of the carriage 10. However, the comb housing 52 is provided, on one side, with two downwardly and inwardly directed lugs 67 68 which are positioned to be in alignment with the bearings 61, 62 mounted on the protruding ends of the shaft 60 which supports the lifting comb 51. The lugs 67, 68 constitutes support for the bearings 61, 62. Thus the lifting comb 51 is mounted for rotation about the axis of the shaft 60 within the housing 65.

The upper part 66 of the lifting comb housing 65 is provided with apertures 69, 70 which can be brought into alignment with corresponding apertures 71, 72 formed in the upper part 12 of the carriage 10 to enable the lifting comb housing 65 to be secured in position by means of bolts and nuts, 73, 74, 75, 76. The upper part 66 of the comb housing 65 also has apertures 77 to accommodate the plungers and an aperture 78 to be aligned with the aperture 50.

The lower portion 30 of the plungers extend downwardly, passing through apertures 80, 81, 82, 8 3 formed for that purpose in the base I I of the carriage 10. Each plunger is a snug fit within the relevant aperture.

The flat base 4 of the rail I is provided with plurality spaced apart apertures 84, 85, 86, 87, 88 as can be seen in Figure 2.

8.

It is to be appreciated that when the described components of the vehicle seat rail assembly have been assembled, the plungers 24, 25, 26, 27 will be biased downwardly by the springs 32, 33, 34, 35 since the lower ends of the springs will be contained within the blind bores 29 formed in the relatively large diameter upper portions 28 of each pluriger and the upper ends of the springs will be engaged by the dimples 39 formed on the cover element 36. As can be seen from Figure 2, the spacing between the plungers 24, 25, 26, 27 and the dimensions and spacing of the apertures 84, 85, 86, 87, 88 in the flat base 4 of the rail are so selected that in any position of the carriage two plungers located in a locking position in which they will extend downwardly through apertures formed in the flat base 4 of the rail, thus securing the carriage 2 from axial movement in either direction.

It is to be appreciated that a bowden cable may be provided, which cooperates with the upwardly extending flanges 42, 43 provided at the ends of the head 40 of the cover element 36, with the bowden cable cooperating with the actuating arm 64. If the bowden cable is actuated the operating arm 64 will rotate about the axis of the shaft 60, causing the comb 51 to rotate. The comb 51 is located so that the fingers of the comb extend between the plungers, with the smaller diameter portions of the plungers being received in the spaces between the fingers of the comb. Thus the fingers of the comb are located beneath the shoulder of each plunger between the greater diameter upper portion 28 and the smaller diameter lower portion 30. If the comb is rotated the fingers will move upwardly and will engage the shoulders of any plungers which have been biased downwardly by the springs so that the lower ends of the plungers extend through apertures formed in the flat base 4 of the rail. As the comb continues to rotate so it will lift the plungers that it engages upwardly to a retracted position this will disengage the plungers from the apertures formed in base 4 of the rail. Thus, with the comb rotated to lift the plungers to 9. the retracted position the carriage may be moved axially. When the comb is returned to its initial position the plungers will again be biased downwardly by C) the springs and, as a consequence of the dimensioning of the plungers and the apertures at least two plungers will engage with apertures formed in the flat base 4 of the rail.

The lower part I I of the carriage, or at least the portion of the lower part I I of the carriage defining the apertures 80, 81, 82, 83 through which the portions 30 of the plungers of lesser diameters extend, is formed of a defonnable or malleable material.

Figure 3 illustrates two plungers 24, 25 that engage two apertures 84, 85 formed in the rail 1. The plungers are located so that the groove or recess 31 is received within the aperture 80, 8 1.

In the event that an accident arises, a force, as indicated by the arrow F in Figure 4, may be applied to the carriage. The force may be such that part of the plunger 24 becomes deformed. However, more importantly, it is to be noted that the force is such that the maten' al forming the lower part I I of the carriage is deformed, or at least the material that actually defines the periphery of the aperture 80 is deformed. The result is that part of the material is brought into engagement with the formation constituted by the peripheral groove or recess 31. The material brought into engagement with the recess engages an engagement face, constituted by the lower surface 90 of the recess as shown in figure 4, which extends generally transversally to the axis of the plunger. The engagement of the deformed material from the carriage 11 and the engagement face 90 prevents the plunger 24 from moving upwardly. Thus then plunger 24 is retained in engagement with the aperture 80 formed in the flat base 4 of the 10. rail 1. Thus, the plunger is prevented from moving towards the retracted position in which the carriage might be free to move along the rail.

In the present specification "comprise" means "includes or consists of' and "comprising" means "including or consisting of'.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utillsed for realising the invention in diverse forms thereof.

Il.

Claims

CLAIMS:

A vehicle seat rail arrangement, the arrangement comprising an elongate rail and a carriage mounted on the rail for axial movement along the rail, the carriage being provided with at least one plunger, the plunger being biased towards a locking position which part of the plunger extends through an aperture formed in part of the carriage and into engagement with engagement means provided on the rail to retain the carriage in a fixed position, means being provided to retract the plunger fi-oni the locking position to enable the carriage to be moved axially of the rail, the pail of the plunger which extends through said aperture being formed with a formation that presents a face that extends generally perpendicularly to the axis of the plunger, the material forming at least the part of the carriage in which said aperture is formed being deformable so that if a substantial force is applied to the carriage the material will deform and engage the engagement face formed on the plunger to prevent the plunger from moving towards said retracted position.
2. An arrangement according to claim 2 wherein the formation is a groove formed in the periphery of the plunger.
3. An arrangement according to claim 2 wherein the groove has two opposed parallel sides which extend transversely to the axis of the plunger.
4. An arrangement according to any one of the preceding claims wherein there plurality of plungers, the rail being provided with engagement means 12. adapted to the engage at least some of said plungers whenever the carriages in a selected one of a plurality of predetermined positions.
5. An arrangement according to any one of the preceding claims wherein means to retract the or each plunger from the locking position comprises a lifting comb, the lifting comb having a finger or fingers adapted to be adjacent the or each plunger, means being provided to move the lifting comb to bring the finger or fingers to engagement with an abutment on each plunger to lift the plunger against a spring bias.
6. A vehicle seat rail arrangement according to any one of the preceding claims in combination with a vehicle seat mounted on the carriage.
7. A vehicle seat rail arrangement substantially as herein described with reference to and as shown in the accompanying drawings.
8. Any novel feature or combination of features disclosed herein.