GB2322295A - Height adjustable and pivotable seat arrangement - Google Patents

Abstract

A vehicle seat arrangement comprises an upright support for anchoring in a vehicle, which support carries an arm 5 projecting substantially radially therefrom, a seat (1, Fig. 2) mounted on arm 5, a first assembly for adjusting the height of arm 5 and a second assembly for swinging arm 5 in a limited arc about the axis of the support. Preferably, the support includes a tubular column 6 in which the height adjustment assembly may be housed. The height adjustment assembly may be connected to arm 5 via a longitudinal slot 9 in column 6 and may include a screw shaft 12 which is typically engaged at its lower end by an electric motor 18. Screw shaft 12 may be co-axial with column 6 and may be threadedly engaged with a sleeve 13 having a lateral extension 14 through slot 9 to carry arm 5. The support may be fixed and arm 5 may be hinged to the height adjustment assembly. Column 6 may also be rotatable about its axis to facilitate swinging of arm 5.

Description

ImDrovements relatinq to Vehicle Seats This invention relates to vehicle seats.

Seats for the disabled or the handicapped which swivel between a forward facing position and a sideways facing one, projecting wholly or partially through an opened doorway have been well established for a good number of years.

However, while these are satisfactory for "ordinary" cars, some vehicles present a different problem, for example the Purpose Built Taxi design. This has a passenger compartment divided from the driver by a partition, and the seating arrangement often includes a bench seat across the back and rearward facing tip-up seats attached to the partition. The floor of this compartment is generally rather higher than that of a saloon car. Present swivelling seat arrangements are not appropriate for installation in such vehicles, and it is the aim of this invention to provide one that is.

According to the present invention there is provided a vehicle seat assembly comprising an upright support for anchoring in a vehicle adjacent a door, an arm carried by the support and projecting generally radially therefrom, means for raising and lowering the arm, means for swinging the arm part circumferentially about the support, and a seat mounted on the arm.

The seat will preferably have a back rest whose plane is generally radial to the support.

This seat may be of the tip-up kind, so that the seat base that is actually sat upon can fold up against the back rest. The folding and unfolding action can be arranged to shift the back rest between substantially vertical and sloping attitudes, the latter to obtain when the seat base is down.

As indicated above, this is particularly suitable for taxis with a partition between the driver and the passenger compartment. The support will then be anchored in a forward corner of the rear compartment, generally on the near side of the vehicle, so that the seat will have a stowed position against the partition. With the seat swung through approximately 900 to face out through the doorway, when the seat base is down it may project beyond the side of the vehicle.

Having been swung to this position, and the passenger's feet having cleared the floor of the vehicle with the seat at its maximum height during this movement, it can then be lowered to floor level where it should be at a convenient height for a partially disabled or handicapped passenger to dismount the seat. For taking such a passenger into the taxi, or simply for stowing the seat after setting down a passenger, the movements are reversed with the arm first being raised and then swung in and forwards against the partition.

In the preferred form, the support includes a tubular column anchored at the top and bottom, where it is carried by the floor of the passenger compartment. A mechanism for raising and lowering the seat can be housed within the column and connected to the arm via a longitudinal slot.

Outside the column, the mechanism may carry a bracket to which the arm is hinged. Preferably, the slot will face in the opposite direction to that of the seat, that is forwards towards the partition, so that it will not generally be visible.

This mechanism may comprise a lead screw co-axial with the column and carried by a bearing at the top, or at least above the slot, so that it is in tension. The lower end of the screw may simply be located co-axially with the column and have an engagement with a drive unit. This may be a small electric motor with a gear or pinion meshing with an internally toothed ring at the lower end of the lead screw.

An internally threaded sleeve or a carriage with a ball nut assembly (hereafter just a sleeve for convenience) is carried by the lead screw and connected by a neck passing through the slot to the external bracket. This neck will stop the sleeve rotating, and so as the lead screw is rotated the sleeve is forced to move up or down.

It is advisable to have a restraint to retain the free end of the arm at at least one end of its limited arc. This may serve as an additional support. The free end of the arm can be provided with a projection adapted to fit within an upright guide that will be secured to the partition. This guide will be positioned so that when the seat is fully raised the arm can be swung forward against the partition, but on lowering it from this position, the projection enters a channel in the guide and thereby holds the arm against swinging. The arm may be lowered until it comes to rest on a stop at the base of the guide, this providing additional support. While this projection may be a fixed slide element, it will be preferred to have roller means for co operating with the channel.

There could be a similar restraint on the door frame into which the end of the arm is lowered having completed its outward and rearward swing.

Refinements may include co-operating sensors and/or switches to ensure that only certain combinations of movements of the seat are possible, having regard to the height and rotated position of the seat. There will then be no risk of lowering a passenger prematurely to the floor or of dragging legs over the door cill.

For a better understanding of the invention, one embodiment will now be described, by way of example, with reference to the accompany drawings, in which: Figure 1 is a diagrammatic face view of a vehicle seat assembly with the seat ready to use, Figure 2 is a diagrammatic side view of the assembly of Figure 1, Figure 3 is a diagrammatic plan view of the assembly of Figure 1, Figure 4 is a vertical section through a support and adjustment mechanism for the seat, and Figure 5 is a side view of a restraint for the seat.

A seat 1 has a back rest 2 and a base 3 which can be folded down to a substantially horizontal position, as shown in full lines in the figures, for passenger use, or hinged up to lie flat against the back rest 2, as shown in dotted lines in Figure 2. When the base 3 is down, the back rest may be inclined slightly as shown in Figure 2, but when it is folded up a linkage may cause the back rest to adopt a more vertical attitude.

This seat is intended as a replacement for one of the usual fixed tip-up seats mounted on the rear of a partition 4 between the passenger compartment and the driver in a taxi, which is assumed here to be for driving on the left hand side of the road. It is placed on the left hand side looking forward so that the near side door is used by the handicapped passenger. The seat is carried by a horizontal arm 5 supported from a vertical column 6 secured to the floor 7 of the passenger compartment and either to the partition 4, to the roof or to the side wall of the vehicle body above the door opening 8.

Referring now also to Figure 4, the column 6 is tubular and it has a longitudinal slot 9 facing the partition 4, from which it is spaced by a short distance. Internally, a bearing 10 rotatably supports the head 11 of a co-axial lead screw 12 on which a sleeve 13 is threaded. A neck 14 projects radially from the sleeve through the slot 9 and externally of the column carries a bracket 15. The arm 5 is hinged to this so that it can swing about a vertical axis through 900. At the lower end of the lead screw 12 there is an internally toothed annulus 16 with which a pinion 17 meshes, being driven by an electric motor 18.

A restraint 19 (Figure 5) is fixed to the partition 4 to co-operate with the free end of the arm 5 when the seat is in use or stowed. This restraint comprises a channel member, the channel being open towards the column 6. The end of the arm 5 carries two rollers 20 whose axes are parallel to the length of the arm, one above the other and slightly off-set horizontally. They are positioned so that when the arm 5 is lowered from above the restraint 19, the rollers 20 enter the channel and engage opposite flanges.

The restraint may further comprise a stop 21 at its lower end on which the end of the arm 5 can bear.

A similar restraint can be mounted on the inside of the door frame to receive the end of the arm 5 when that is swung to the fore and aft direction and lowered.

To pick up a handicapped passenger, the seat 1 is folded down into the in-use position and the near side passenger door opened. It is then in the full line position of Figure 1. The motor 18 is energised to rotate the screw 12 and raise the sleeve 13 sufficiently for the rollers 20 to come clear of the restraint 19. Then the arm 5 is swung away from the partition 4 for the seat to face outwardly through the doorway 8, as in the full line position of Figure 3. The motor 18 is reversed to lower the seat 1 substantially to the level of the floor 7, as shown in the dotted line position of Figure 2. At this point the neck 14 may bottom on the lower end of the slot 9, while the free end of the arm 5 may be supported by the doorframe restraint referred to above. The passenger can then mount and, when safely on, the motor 18 is driven to lift the seat to its maximum height. This may be defined by the upper end of the slot 9. The passenger's feet should then be clear of the floor 7. The seat 1 is then swung in on its arm 3 and forwards against the partition 4. Finally, the seat is lowered for the rollers 20 to engage the restraint 19 and, if provided, the stop 21 will then support the free end of the arm 3. This final vertical movement should bring the passenger's feet back on to the floor 7.

The demounting sequence is simply the reverse of this.

This assumes that the door opening 8 is sufficiently high for the head of a passenger on the seat 1 to pass freely into the vehicle. If the doorway is less high there may have to be a compromise, with the seat being lowered to a certain extent before it reaches the full line position of Figure 2.

It is not considered necessary at present to provide power to swing the arm 5, although it is an option. Various safety measures can be included, such as sensor governed switches which would not allow the seat to be fully lowered unless in the doorway 8. It could also be arranged for the vehicle to be immobilised unless the arm 5 was properly engaged with the restraint 19.

As an alternative to hinging the arm 5 to the bracket 15 it could be fixed to that bracket with the column itself on bearings allowing the whole assembly to be rotated about the axis of the column through 900.

There is a further option of having the arm 5 nonrotatable with respect to the column, and arranging for the column itself or other support to track round in a tight arc to swing the arm between its extreme positions.

It will be understood that other means for raising and lowering the arm could be provided, such as hydraulic, but the mechanical lead screw with electric motor drive is presently preferred.

It is also possible to adapt the seat to help restrain a wheelchair. When stpwed against the partition, a wheelchair may be backed up to it (the passenger facing rearwardly of course) and be located. A suitable abutment may be provided on the underside of the seat base 3. Straps or other restraining means would then be fastened to secure the wheelchair.

Claims (14)

1. A vehicle seat assembly comprising an upright support for anchoring in a vehicle adjacent a door, an arm carried by the support and projecting generally radially therefrom, means for raising and lowering the arm, means for swinging the arm in a limited arc about the axis of the support, and a seat mounted on the arm.

2. A vehicle seat assembly as claimed in Claim 1, wherein the seat has a back rest whose plane is generally radial to the support.

3. A vehicle seat assembly as claimed in Claim 2, wherein the seat can fold up against the back rest.

4. A vehicle seat assembly as claimed in Claim 3, wherein the folding and unfolding action is arranged to shift the back rest between a substantially vertical attitude when the seat is up and a sloping attitude when the seat is down.

5. A vehicle seat assembly as claimed in any preceding claim, wherein the support includes a tubular column with anchorage means at top and bottom.

6. A vehicle seat assembly as claimed in Claim 5, wherein the means for raising and lowering the arm is housed within the column and is connected to the arm via a longitudinal slot in the column.

7. A vehicle seat assembly as claimed in Claim 6, wherein the raising and lowering means includes a lead screw co- axial with the column and a sleeve threadedly engaged therewith, the sleeve having a lateral extension through the slot to carry or form the arm.

8. A vehicle seat assembly as claimed in Claim 7, wherein the lead screw is suspended from a bearing above the slot, its lower end being engaged by a drive unit.

9. A vehicle seat assembly as claimed in Claim 8, wherein the drive unit is a motor with a pinion meshing with an internally toothed ring at the lower end of the lead screw.

10. A vehicle seat assembly as claimed in any one of Claims 5 to 9, wherein the tubular column is rotatable about its axis to swing the arm in said limited arc.

11. A vehicle seat assembly as claimed in any one of Claims 1 to 9, wherein the support is fixed and the arm is hinged to said raising and lowering means.

12. A vehicle seat assembly as claimed in any preceding Claim, and further comprising a restraint to retain the free end of the arm at at least one end of its limited arc.

13. A vehicle seat assembly as claimed in Claim 12, wherein the or each restraint is an upright guide whose upper end is below the maximum raised position of the arm at said one end of its limited arc, the free end of the arm entering the guide to be trapped thereby when the arm is lowered from that raised position.

14. A vehicle seat assembly as claimed in Claim 12 or 13, wherein the or each restraint also serves to support the free end of the arm co-operating therewith.