GB2255902A

GB2255902A - "adjustable vehicle seat"

Info

Publication number: GB2255902A
Application number: GB9209140A
Authority: GB
Inventors: Peter Bertenburg; Hatsuo Hayakawa; Mikio Honma; Nobuyuki Koizumi
Original assignee: Keiper Recaro GmbH and Co; Ohi Seisakusho Co Ltd
Current assignee: Keiper Recaro GmbH and Co; Ohi Seisakusho Co Ltd
Priority date: 1991-05-21
Filing date: 1992-04-28
Publication date: 1992-11-25
Anticipated expiration: 2012-04-28
Also published as: DE4116505C1; ITMI921183A1; JPH05170017A; IT1255994B; GB2255902B; GB9209140D0; ITMI921183A0; JP2637875B2

Description

2 2 _) 5 _) -1 1 VEHICLE SEAT, MORE PARTICULARLY A MOTOR VEHICLE SEAT 1

The invention relates to a vehicle seat, more particularly to a motor vehicle seat, with adjustable seat depth,

exhibiting the features of the preamble of Claim 1.

In this specification the 'depth' of the seat is the dimension between the front upper edge of the squab and the base of the backrest.

On conventional vehicle seats of this type the front section of the upholstery support of the seating part is only held in the position giving the desired seat depth by the friction between the bars and the bushings adapted to be longitudinally displaceable thereon and the friction between the two bars and respective clamping springs which limit the amount by which the front section can be displaced away from the rear section. Although as a rule this friction is entirely sufficient to prevent the seat depth from being adjusted unintentionally, at high levels of acceleration or deceleration such as may occur in an accident it is not absolutely impossible for the front section to be displaced inadvertently.

It is therefore the object of the invention to create a vehicle seat with adjustable seat depth, on which the front section of the upholstery support of the seating part, whilst being sufficiently easy to move, nevertheless cannot be moved unintentionally. This object is achieved by a vehicle seat exhibiting the features in Claim 1.

The pawl or pawls prevent the associated pinion from turning in the locked position. Since it is not possible 2 C 't for the front section to be displaced without the pinion turning, locking the pinion makes it impossible for the front section to be displaced even at high acceleration or deceleration. The f act that the pinion can be locked by means of the pawl is also advantageouus in that the friction that has to be overcome during displacement does not need to reach a given level in order to prevent unintentional displacement, as is the case with the conventional seats. Instead the guide can be f ree-running.

Although it is also possible to connect the bars rigidly to the front section and provide the guide sleeves on the rear section, in one preferred embodiment the bars are joined rigidly to the rear section and the bushings on both bars are rigidly joined to the front section and preferably integral therewith. The shaft carrying the two pinions is then pivotably mounted in the front section, which also results in the pawl or pawls being mounted on the front section. Little extra engineering is then required to provide an operating handle for operating the pawl or pawls. Moreover, ease of operation is possible without the operating handle being obtrusive, for it can be arranged on the lower face of the front section near the front end.

Each pawl that is provided preferably incorporates a hole into which the pinion engages and into which each of the teeth on the pawl projects. Such a hole is a simple method of enabling the pawl to be positioned in relation to the pinion. This substantially simplifies the mounting of the pawl or pawls.

The invention will now be described in detail with the help of one embodiment represented in the drawing, wherein:

Fig. 1 shows an incomplete longitudinal view of the embodiment with the pawl in the locking position; 1 3 Fig. 2 is a cross-section corresponding to Fig. 1, showing the pawl in the release position; Fig. 3 is embodiment; an incomplete cross-section through the Fig. 4 is a view of the two pawls and the grip bar which connects them; Fig. 5 is a cross-section taken along line V-V in Fig. 4.

A motor vehicle seat with adjustable seat depth includes a rear section 1 of its upholstery support for the seat trim, which support is joined directly or via a height adjustment mechanism to two slides (not shown) which extend in the longitudinal direction of the seat and are adapted to run longitudinally in guide rails and to be fixed in a selected position, said guide rails being joined to the floor of the vehicle. On the rear section 1 is f ixed the rear end portion of two guide bars 2 which extend forwards in the longitudinal direction of the seat and symmetrical to the centre of the seat. A guide bushing 3 is arranged on each of these two guide bars 2 in longitudinally displaceable manner. As Figs. 1 and 3 show, the two guide bushings 3 are integral with a plastic front section 4 of the upholstery support for the seat trim. This f ront end section 4 can therefore be displaced in the longitudinal direction of the seat along the two guide bars 2 relative to the rear section 1, thereby enabling the seat depth to be adjusted. For the sake of clarity neither the front part of the seat trim, which is carried by the f ront section 4, nor the rear portion of the seat trim carried by the rear section 1, is depicted.

The two guide bars 2 have a toothed rack 21 on their upward-facing side. A pinion 5 engages each of these two 4 racks 2'. The two pinions 5 sit locked against rotation and axially immovable on a connecting shaft 6 which extends transverse to the seat, said shaft 6 being pivotably mounted in the top section 4 by means of a respective mounting 7 and forcing the two pinions 5 to be synchronised, which helps counteract tilting of the front section 4 when the seat depth is adjusted.

Arranged alongside the outward-facing side of each of the two guide bushings 3 is a pawl 8 in the form of a lever and preferably made of Plastic, as can be seen in particular from Fig. 3. The two pawls 8 are identical in construction. For mounting them on the front section 4, a journal 9 is formed internally near the lower end portion, running parallel to the connecting shaft 6 and on its free end presenting a radially projecting bracket 9'. The two journals 9 engage rotatably in respective slots 10 in lateral wall portions of the front section 4 and are displaceable in the longitudinal direction thereof. The downwardopening slot 10 extends to the connecting shaft 6 and is provided in a bearing cheek 11 which extends downwards from the guide bushing 3, said cheek being engaged from behind by the bracket 9'.

Joined to the bottom ends of the two pawls 8 is a connecting and grip bar 12, forming an integral bent angle lever and, as Fig. 1 shows, extending along the lower face of the front section 4 and, as shown by Fig. 5 in particular, its mid-section forming a downward-opening grab moulding 12'. Two pretensioned helical compression springs 13, which press from above onto the two end portions of the connecting and grip bar 12 and are also supported on the f ront section 4, exert a torque on the two pawls 8 which operates counter- cl ockwi se when viewed in the direction shown in Figs. 1 and 2.

The top end portion of the two pawls 8 is equipped with a hole 14, the size of which in the longitudinal direction of the pawl 8 matches the external diameter of the pinions 5. This is because each of the two pinions 5 engages in the hole 14 in the pawl 8 associated with it, as can be seen in particular from Figs. 2 and 3. The hole 14 does not hamper rotatational movement of the pinion 5. However, the two surfaces delimiting the hole 14 above and below form guide surfaces which define the position of the pawl 8 in relation to the pinion 5. Thanks to the way the journals 9 are mounted in the slots 10, this positioning is not hampered by the journals 9.

In the direction in which the pawls 8 swivel the hole 14 is larger in size than the sum of the diameter of the pinion 5 and the height of teeth 15 which protrude radially from the rear, semi-circularly curved boundary wall of the hole 14 and in form match the teeth of the pinion 5. These teeth 15 engage the pinion 5 when the two pawls 8 are in the locked position depicted in Fig. 1, in which position the pinion 5 rests against one of the rear boundary faces of the hole 14. In this position the two helical compression springs 13 try to hold the pawls 8, for the torque which they exert on the pawls 8 operates in the forward direction, attempting to swivel the pawls 8. When the two pawls 8 are in the locked position it is not possible to adjust the seat depth, because the rotational movement of the pinions 5 required to do so is prevented by the teeth 15 of the pawls 8. Before the seat depth can be adjusted, the connecting and grip bar 12 must be pulled upwards against the force of the helical springs 13. This swivels the two pawls 8 backwards into the release position depicted in Fig. 2. The brackets 9' of the journals 9 which engage the bearing cheeks 11 from behind do not obstruct this swivel movement. They merely secure the two 6 pawls 8 against being displaced in the longitudinal direction of the journals 9.

Once the connecting and grip strip 12 has been released, the two pawls 8 automatically return to their locked position.

The maximum adjustable seat depth is determined by means of respective leg springs 16, which are disposed on the rear end portion of the two guide bushings 3 and resiliently rest with one leg against the guide bar 2 thanks to a slot in the guide bushing 3. In the position of maximum seat depth this leg engages in a notch provided on the lower face of the guide bar 2 as illustrated.

All the features mentioned in the foregoing description, as well as any that can be taken only from the drawing, are additional embodiments and as such part of the invention, even if they are not given special prominence and not specifically mentioned in the claims.

7

Claims

CLAIMS:

1. An upholstery support for the squab of a vehicle seat having adjustable seat depth, the support including a rear section and a front section which can be displaced relative to said rear section so as to adjust the seat depth, wherein a) the front section is carried by two bars which extend in the direction of displacement, b) the two bars are each provided with a toothed rack, c) a respective pinion engages with each of the two racks, and d) the two pinions are arranged locked against rotation on a shaft which extends at right angles to the direction of displacement, characterised in that associated with at least one of the two pinions (5) is a pawl (8) which can be moved manually against the force of a pullback spring (13) out of a locking position, in which at least one tooth (15) of the pawl (8) is in engagement with the teeth of the pinion (5), into a release position in which said pawl (8) is inoperative.

2. A support according to claim 1, characterised in that the pawl (8) is mounted on the front section (4) of the upholstery support for the seat cushion trim and incorporates an operating handle (12).

3. A support according to claim 2, characterised in that the operating handle (12) is arranged on the lower face of the front section (4), extends transverse to the seat and connects the pawl (8) associated with one pinion (5) to the pawl (8) associated with the other pinion (5).

4. A support according to one of claims 1 to 3, characterised in that each pawl (8) incorporates a hole (14) in which the associated pinion (5) engages and into which each of the teeth (15) of the pawl projects, and in that the size of the hole (14) is larger in the direction of movement of the pawl (8) than the diameter of the pinion (5).

5. A support according to claim 4, characterised in that the size of the hole (14) matches the diameter of the pinion (5) at right angles to the direction of movement of the pawl (8).

6. A support according to claim 5, characterised in that the pawl (8), is a lever which is mounted with clearance on the front section (4) by means of a lpin (9), said pin extending parallel to the shaft (6).

7. A vehicle seat incorporating a support according to any preceding claim.

8. Vehicle seat.. more particularly a motor vehicle seat, with adjustable seat depth, the upholstery support for the seat trim of which incorporates a rear section and a front section which can be displaced relative to said rear section so as to adjust the seat depth, wherein a) the front section is carried by two bars which -gextend in the direction of displacement, b) the two bars are each provided with a toothed rack, c) a respective pinion engages with each of the two racks, and d) the two pinions are arranged locked against rotation on a shaft which extends at right angles to the direction of displacement, characterised in that associated with at least one of the two pinions (5) is a pawl (8) which can be moved manually against the force of a pull- back spring (13) out of a locking position, in which at least one tooth (15) of the pawl (8) is in engagement with the teeth of the pinion (5), into a release position in which said pawl (8) is inoperative.

9. An upholstery support substantially as described with reference to the accompanying drawings.

10. A vehicle seat incorporating an upholstery support substantially as described herein with reference to the accompanying drawings herein