GB2293318A

GB2293318A - vehicle seat assembly with safety beam

Info

Publication number: GB2293318A
Application number: GB9419170A
Authority: GB
Inventors: Andrew Richard Henshaw
Original assignee: Nissan Technical Centre Europe Ltd
Current assignee: Nissan Technical Centre Europe Ltd
Priority date: 1994-09-22
Filing date: 1994-09-22
Publication date: 1996-03-27
Anticipated expiration: 2014-09-22
Also published as: GB9419170D0; GB2293318B

Abstract

A transverse beam 4 for supporting two tiltable seat backs 1, 2 has its end portions releasably locked to side portions 7a, 7b of the vehicle body. The seat backs 1, 2 are releasably locked to the beam 4 at positions 9b, 11b spaced from its end portions. Each seat back is forwardly tiltable to an inoperative position (as shown) when it is disengaged from the beam (and, if necessary, the vehicle body). The beam 4 is separable from the seat backs 1, 2 and the vehicle body when it is released from the seat backs and the vehicle body. Thus, when the seat backs are tilted forward, the transverse beam 4 can be left in place to restrain a load or can be stowed in a convenient position in the enlarged load space. <IMAGE>

Description

Vehicle Seat Assembly This invention relates to a vehicle seat assembly and in particular to a seat assembly whose seat back is movable between a tilted inoperative position and an upright operative position.

The rear passenger seat of an estate car or hatchback usually has a seat back which can be tilted forwards to enlarge the load carrying space in the rear. It is now common to split the rear seat so that it has two tiltable seat backs, one of which is tiltable independently of the other. Usually, one of these seat backs will be wider than the other and the load carrying space is usually hidden from general view by a removable parcel shelf assembly which does not form a structural part of the vehicle.

In the upright operative position, the or each seat back of the rear passenger seat of such vehicles is releasably latched to part of the bodywork. However, as there is only a removable parcel shelf and not a structural support member to the rear of the seat backs, the inboard end of each seat back is unrestrained and is only held in place by the integral structural rigidity of the'seat backs.

Furthermore, there is now an increasing requirement for the upper part of the seat backs to incorporate one or more seat back retractors or at least a belt bearing location. This is particularly the case when three rear passengers are each to be provided with a three-point seat belt. As will be appreciated, in an impact situation, this arrangement can subject the seat back to an additional load particularly in the area where the seat belt for the rear centre seat passes over or is attached to the centre portion or inboard end of one of the seat backs. This can cause dislodgement or distortion of the seat back, unless the seat back is provided with substantially structure reinforcement, which can cause the seat to become very cumbersome and unacceptably heavy to use.

GB-B-2249339 (Autoliv Development AB) discloses a locking mechanism for the back of a vehicle seat, in which a locking element consisting of a cross-beam pivotally mounted on the seat back is adapted to engage abutments on each side of the vehicle. This adds to the weight of the seat back which has to be tilted between its operative and inoperative positions. Furthermore, it is not applicable to a split rear seat.

Accordingly, it would be desirable to be able to provide a seat back with enhanced support but without adding encumbrance to movement of the seat back.

The present invention provides a transverse beam which supports the seat back in its operative position and which is removable to an arbitrary location.

In particular, the invention provides a seat assembly for a vehicle, the seat assembly including a seat back which is movable between an operative position and an inoperative position, a transverse beam for supporting the seat back in its operative position, first releasable means for connecting one end portion of the transverse beam to a first side portion of a body section of the vehicle, second releasable means for connecting the other end portion of the transverse beam to a second side portion of a body section of the vehicle, third releasable means for connecting the seat back to the transverse beam at a position spaced from its end portions, and, optionally, at least one further releasable means for connecting the seat back to the transverse beam or a body section of the vehicle, the seat back being locked in its operative position when all the said releasable means are engaged, the seat back being movable to its inoperative position when the third releasable means and optional further releasable means are disengaged, and the beam being separable from the seat back and the vehicle body when all the said releasable means are disengaged.

Preferred and optional features are set forth in the subsidiary claims.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a fragmentary schematic front perspective view of a first embodiment of a seat arrangement in a vehicle, with a first seat back in the upright operative position and a second seat back in the forwardly tilted inoperative position; Figure 2 is a view similar to Figure 1, but showing both seat backs in the inoperative position; Figure 3 is similar to Figure 2 and shows a second embodiment; and Figure 4 is similar to Figure 3, but with a transverse beam shown in a stowed position.

The seat arrangement shown in Figures 1 and 2 is mounted in the rear passenger space of a vehicle such as a hatchback or estate car. The seat arrangement comprises a seat which is split laterally into two parts, one of which is wider than the other and occupies approximately two thirds of the width of the passenger space. Each part includes a seat cushion (not shown) which is pivotably mounted to the floor of the vehicle body so as to be forwardly tiltable to an approximately vertical portion, and a seat back (1 or 2) which is also mounted to the floor so as to be pivotable between an upright operative position and a forwardly tilted inoperative position in which it is approximately horizontal. Figure 1 shows the first, wider seat back 1 in its operative position and the second, narrower seat back 2 in its inoperative position.

As shown in Figure 1, the first seat back 1 includes a central arm-rest 3 which is pivotable between a generally horizontal active position (shown in full line) and an upright inactive position (shown in chain-dotted line). Each seat back also carries, optionally, a removable head-rest 6 at its upper end.

A removable structural beam 4 is mounted transversely to the vehicle body and extends across horizontally immediately behind the upper end portions of the upright seat backs 1,2. The transverse beam 4 is a box beam (of square or rectangular cross-section) with an upright front wall 4a, against which the seat backs 1,2 rest, and a generally horizontal top wall 4b, which is substantially flush with the upper end of each seat back. One end of the transverse beam 4 extends beneath an inwardly projecting side portion 7a of the vehicle body and is connected to this side portion by a first releasable locking device including a release lever 8a.

Similarly, the other end of the beam 4 is connected to an opposite side portion 7b by a second releasable locking device with a release lever 8b. The skilled person will be aware of many locking devices which are available for this purpose and which need not be described in detail here. In particular, a spring-loaded latching hook could engage a lug carried by the transverse beam.

The seat back 1 is connected to the transverse beam 4, at a position spaced from its end portions, by means a third releasable locking device comprising co-operating parts 9a and 9b on the seat back and the beam respectively, as shown in Figure 2. Similarly, the narrower seat back 2 is connected to the beam 4, at a position spaced from its end portions, by a further releasable locking device comprising two co-operating parts Ila and 11b on the seat back and beam respectively. Again, the skilled person will be aware of many locking devices which are available for this purpose and which need not be described in detail here.

Further releasable locking devices may be provided for locking outboard ends of the seat backs 1, 2 to side bolsters 14a, 14b of the vehicle body in a conventional manner. A further releasable locking device may also be provided for connecting the arm-rest 3, in its raised inactive position, to the transverse beam 4.

The wider seat back 1 carries two seat belt retractors 12, and the other seat back 2 carries a single retractor 12. The beam 4 carries three actuating elements 13 which engage in the retractors 12 when the seat backs 1, 2 are in their operative positions. Each belt retractor is of a type which is adapted to prevent belt pay-out when the actuating element is not engaged in the retractor, e.g. if the upright seat back is not correctly connected to the transverse beam. Of course, the belt retractor prevents belt pay-out if it is in the wrong attitude, if it is subjected to abnormal acceleration, or if the belt is pulled abruptly. Such retractors are well known to those skilled in the art.

Accordingly, when the transverse beam 4 is locked in position by the first and second releasable locking devices and the seat back 1 or 2 is locked to it, the seat back is substantially reinforced against distortion or dislodgement arising from forces due to accidental impact, whether from the front or the rear.

When the seat backs 1,2 are to be tilted forwards, the locking devices 9a/9b and lla/llb are released (as well as any further locking devices connecting the seat backs to the vehicle body or the transverse beam 4), so that each seat back is free to tilt forwards to its inoperative position independently of the other seat back and independently of the transverse beam 4. The beam can thus be left in position to assist in restraining large or heavy loads, or to support a parcel shelf (which may be releasably hinged to the rear edge of the beam).

Alternatively, if both seat backs are to be lowered simultaneously, for example, the locking devices 9a/9b and lia/lib can be left engaged, the seat backs can be unlatched from the vehicle body, and the release levers 8a and 8b can be operated so that the transverse beam 4 can be lowered together with the seat backs so that it is safely stowed. When the seat backs are to be raised again, the locking devices 9a/9b and lla/llb can be disengaged so that the transverse beam can first be mounted on the side portions 7a and 7b of the vehicle body before the seat backs 1, 2 are raised (separately or together).

In order to create further space and reduce the load when the seat backs are tilted down, the transverse beam 4 can be removed entirely from the vehicle.

In the second embodiment illustrated in Figures 3 and 4 the seat belt retractors 12 are mounted in the transverse beam 4. Furthermore, the beam 4 extends between the side portions 7a, 7b and the side bolsters 14a, 14b of the vehicle body. Lugs 16a, 16b on the end portions of the transverse beam 4 engage in locking devices 17a, 17b which are releasable by the levers 8a,8b on the side portions 7a,7b of the vehicle body. Thus the beam 4 can be lifted out and locked to the forwardly tilted seat backs 1,2 in the position shown in Figure 4.

Various modifications may be made within the scope of the invention. For example, the release levers 7a, 7b could be arranged in different positions on the vehicle body or on the transverse beam 4. The beam can be used with any combination of split rear seat configurations, e. g. 50:50 or 60: 40, or with a bench-type seat. Thus the provision of the transverse beam allows great flexibility in the interior design of the vehicle.

Claims

1. A seat assembly for a vehicle, the seat assembly including a seat back which is movable between an operative position and an inoperative position, a transverse beam for supporting the seat back in its operative position, first releasable means for connecting one end portion of the transverse beam to a first side portion of a body section of the vehicle, second releasable means for connecting the other end portion of the transverse beam to a second side portion of a body section of the vehicle, third releasable means for connecting the seat back to the transverse beam at a position spaced from its end portions, and, optionally, at least one further releasable means for connecting the seat back to the transverse beam or a body section of the vehicle, the seat back being locked in its operative position when all the said releasable means are engaged, the seat back being movable to its inoperative position when the third releasable means and optional further releasable means are disengaged, and the beam being separable from the seat back and the vehicle body when all the said releasable means are disengaged.

2. An assembly as claimed in claim 1, in which the transverse beam is adjacent an upper end portion of the seat back in its operative position.

3. An assembly as claimed in claim 2, in which the transverse beam is substantially flush with the upper end of the seat back in its operative position.

4. An assembly as claimed in any preceding claim, in which the transverse beam has an upright portion1 adjacent to the seat back in its operative position, and a generally horizontal portion.

5. An assembly as claimed in any preceding claim, in which the transverse beam is a box beam.

6. An assembly as claimed in any preceding claim, in which the seat back includes an arm-rest which is movable between a generally horizontal active position and an upright inactive position, when the seat back is in its operative position.

7. An assembly as claimed in claim 6, including further releasable means for connecting the arm-rest in its inactive position to the transverse beam.

8. An assembly as claimed in any preceding claim, in which when the first and second releasable means are disengaged and the seat back is in its inoperative position, the transverse beam can be separated from the vehicle body and locked to the seat back by the third releasable means.

9. An assembly as claimed in any preceding claim, in which the transverse beam carries at least one head-rest.

10. An assembly as claimed in any preceding claim, in which the transverse beam carries a seat belt retractor.

11. An assembly as claimed in any preceding claim, in which the seat back carries a seat belt retractor.

12. An assembly as claimed in claim 11, in which the transverse beam carries an element which engages with the seat belt retractor when the seat back is in its operative position, the retractor preventing belt pay-out when the element is not engaged with the retractor.

13. An assembly as claimed in any preceding claim, including a second seat back by the side of the first-mentioned seat back.

14. An assembly as claimed in claim 13, in which the second seat back is movable between an operative position and an inoperative position, at least one additional release means being provided for connecting the second seat back to the vehicle body or the transverse beam.

15. An assembly as claimed in claim 13 or 14, in which the first-mentioned seat back has a width at least equal to that of the second seat back.

16. A seat assembly for a vehicle, substantially as described with reference to, and as shown in, Figures 1 and 2 or Figures 3 and 4 of the accompanying drawings.