Motor Vehicle Seat with Adjustable Seat Depth

Abstract

A motor vehicle seat with a seat pan comprising a seat part and a supporting plate, said supporting plate being connected to the seat part via a guide for displacement in a longitudinal direction and comprising a front region forming the front edge of the seat pan. The supporting plate comprises a left and a right supporting wing. The left supporting wing forms the left front corner and the right supporting wing, the right front corner of the seat pan.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Applications DE 10 2007 003 758.0, filed on Jan. 19, 2007 and DE 10 2007 049 863.4, filed on Oct. 18, 2007, both of which are hereby incorporated by reference in their entireties as part of the present disclosure.

BACKGROUND OF THE INVENTION

The invention relates to a seat pan of a motor vehicle seat. In some prior art motor vehicle seats, for example as shown in DE 196 28 381 A1, the supporting plate also forms the left front corner and the right front corner of the seat pan. The supporting plate is approximately T-shaped. If the supporting plate is moved forward, the legs of the T move away from the seat part and a gap forms, which increases as the supporting plate is pushed further forward in the longitudinal direction. This gap is a nuisance both visually and in practical use, it is difficult to conceal, a padding of the seat pan beneath this gap does not abut, it creates a noticeable hollow space. This is disadvantageous.

In the motor vehicle seats as shown in DE 698 27 303 T2, a front seat part is adjusted relative to a rear seat part. The motor vehicle seat as shown in DE 199 13 503 A1 includes a seat pan that also has a front transverse piece and a rear transverse piece that may be spaced different distances apart by means of an adjusting de-vice for adjustment of the seat depth. The invention disclosed herewith does not relate to either of these types of motor vehicle seats.

In the motor vehicle seat as shown in DE 20 2004 020 657 U1, the entire seat part is displaced in the longitudinal direction relative to a seat back and the underframe of the seat. The effective length of the seat pan in the longitudinal direction remains the same. The invention is not concerned with such type of motor vehicle seats either.

In view of the motor vehicle seat of the type mentioned herein above, the object of the invention is to improve the prior art motor vehicle seat in such a manner that a gap between the seat pan and the seat part does not appear as far as practicable, or at least that it is supported as far as possible in order for it not to present a disadvantage and that the thighs will not rest on a side edge of the supporting part.

Accordingly, it is an object of the present invention to overcome one or more of the above-described drawbacks and disadvantages of the prior art.

SUMMARY OF THE INVENTION

The invention is directed to a motor vehicle seat with a seat pan comprising a seat part and a supporting plate, said supporting plate being connected to the seat part via a guide for displacement in a longitudinal direction and comprising a front region forming the front edge of the seat pan. The supporting plate comprises a left and a right supporting wing. The left supporting wing forms the left front corner of the seat pan and the right supporting wing forms the right front corner of the seat pan.

In practical operation, the thighs of a passenger rest on the supporting plate. Depending on the thigh length of an individual passenger, the supporting plate is pushed more or less forward in the longitudinal direction. As a result, a passenger is given the opportunity to adjust the seat to his or her own size, thus achieving the result that the thighs rest on the seat pan up to near the knee, and that they do not undesirably protrude freely too far forward without being supported by the seat front edge. Generally, the supporting plate does not laterally support the thighs, lateral hold being normally provided by the seat part.

The seat pan has a padding that also covers the supporting plate and also an external covering. Padding and covering have a certain elasticity, which however is by far not sufficient to cover all the relative positions between seat part and supporting plate without covering and padding making relative movements.

The padding is supported in the region of the left front corner and of the right front corner of the seat by the two supporting wings. Usually, the padding is configured to be a foam body. The padding retains its contours and does not collapse.

When an adjustment is being made, there is a relative movement between the supporting wings and the seat part. In order to facilitate this movement, and in particular also to avoid any noise, gliding means are preferably provided between the free end of each supporting wing and the seat part.

At their free end, the supporting wings can rest laterally on the seat part, they may however also engage into openings provided on the seat part.

The supporting plate is adjustable in the longitudinal direction with respect to the seat part by means of suited adjustment devices which may be configured to be motor- or hand-driven.

The supporting wings may be connected directly to the supporting plate, they may however also be hinged thereto. In case they are hinged thereto, the joint axis extends substantially perpendicular to the seat surface. The supporting wings always abut the seat part at their free end.

In the longitudinal direction, the supporting plate has a size that is shorter than half the corresponding length dimension of the seat part. It is approximately 30 to 45%. Behind the supporting plate a quite long area is kept free, said area being usually tensioned by springs and serving to receive a passenger's buttocks.

The supporting plate is approximately 25 to 40 cm wide. In one embodiment, the supporting plate is 30 cm wide.

In an advantageous development, the invention suggests fixing the padding to the seat part but not to the supporting plate. The padding assumes different positions with respect to the supporting plate, depending on the length adjustment of the supporting plate. The covering moves together with the padding. As usual, the covering ends underneath the seat pan, its borders are concealed when viewed from a normal angle. Depending on the adjustment of the supporting plate relative to the seat part, the position of the covering border changes. In the region of the supporting plate, the covering is elastically connected to the sup-porting plate or elastically retained. In the first case, springs are provided for ex-ample, said springs being interposed between the supporting plate (or supporting part) and the border of the covering. In the second case, a rubber band or a similar elastic means is sewn into the edge of the covering for example. Advantageously, the padding has a slide coating on its underside in order to facilitate the relative movement between the padding and the supporting plate. Depending on the adjustment of the supporting plate, the front upper seat edge of the seat pan is formed by a different portion of the covering. This edge, which is particularly subjected to wear, changes its position on the covering so that different portions of the covering are subjected to wear and strain.

Other advantages of the present invention and/or of the currently preferred embodiments thereof will become more readily apparent in view of the following detailed description of the currently preferred embodiments and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: is a perspective view of a first embodiment of a motor vehicle seat with adjustable seat depth in accordance with the invention;

FIG. 2: is a top view of the seat pan of the motor vehicle seat as shown in FIG. 1, with padding and covering removed;

FIG. 3: is a cross section in the x-z plane through the center of the seat pan in the retracted position (continuous line) and in the advanced position (dash-dot line) of the supporting plate;

FIG. 4: is a perspective view of the seat pan, the covering is drawn in a dash-dot line;

FIG. 5: is a perspective representation like in FIG. 4 for a second exemplary embodiment; and

FIG. 6: is a perspective representation like in FIG. 4 for a third exemplary embodiment.

DETAILED DESCRIPTION

The motor vehicle seat includes a seat pan 20, a seat back 22 and an underframe 24. The seat pan 20 and the seat back 22 are provided with a covering 26, made for example from fabric or leather. Beneath this covering 26, there is a padding 28, as shown in FIG. 3.

The mechanical and carrying structure of the seat pan 20 has a seat part 30 and a supporting plate 32. Both are displaceable with respect to each other in a longitudinal direction via a guide 34; the FIGS. 1 through 3 show the two extreme positions by way of example, the position with the shortest seat length being shown in a continuous line and the position with the greatest seat length in a dash-dot or dashed line. In the y direction, the supporting plate 32 has a width that only is about 60% of the width of the seat part 30, measured in the same direction. In the position with the shortest seat length, the supporting plate 32 is almost completely located in a recess of the seat part 30 that is open toward the front, meaning in the x direction. On the side of this recess, meaning when viewed in the y direction, the seat part 30 has a left and a right seat part 38 the upper side of which is located higher than the supporting plate 32 in the z direction. These side parts 38 serve to laterally hold the thighs of a user. The thighs of a user rest on the supporting plate 32, which is configured to be large enough for this purpose.

In the position in which the supporting plate 32 projects farthest in the x direction said supporting plate projects significantly forward with respect to the seat part 30. On the left and right side of the supporting plate 32, there are cavities 40. The supporting plate 32 has a front region 42 that forms the front edge of the mechanical structure of the seat part. On each of its extreme regions located in the y direction, there is disposed a supporting wing 44. In the first embodiment, shown in FIGS. 1 through 4, it is respectively hinged about a pivot axis 45 that extends substantially parallel to the z axis. It is elastically biased by a spring (not shown) or another elastic means in such a manner that a free end 46 of the respective supporting wing 44 is biased toward the supporting plate 32 or, put another way, toward the guide 34. It fits against a slide or guide surface 49 on the seat part 30. The left supporting wing 44 forms the left front corner of the seat part 20, the right supporting wing 44, the right front corner of the seat part. In the position in which the seat has the shortest length, the supporting wings 44 fit against the outer surfaces of the side parts 38, leaving but a small space. In the position in which the supporting plate 32 is pushed farthest forward, there is a large space and the supporting wings 44 project slightly further in the x direction than in the case in which the seat has the shortest length.

Substantially, the supporting wings 44 form the foremost side edges of the seat pan 20. They have a profile height of at least 30 mm in the z direction, and substantially a C profile. In one embodiment, they have a profile height of at least 50 mm in the z direction. They can absorb forces in the z direction as they occur in normal operation.

The free ends 46 fit slidingly against the sides of the seat part 30. Preferably, a slide means 48, for example a plastic layer, is provided at the free ends. The free ends 46 show substantially backward in the longitudinal direction 36.

The seat pan 20 has a spring system 50 that bridges a recess in the seat part 30. A hand or motor driven adjustment device 51 is associated with the guide 34, reference being made here to the manual adjustment device according to DE 296 23 565 U1. A motor-driven adjustment device is disclosed in the patent application filed the same day by the applicant “Motor Vehicle seat with Adjustable Seat Depth,” which is fully incorporated herein by reference.

As shown in FIG. 3, a slide surface 52 is interposed between the supporting plate 32 and the padding 28. It is provided either on the supporting plate 32 or, as shown in FIG. 3, on the padding 28. It is made from a plastic foil, for example. It covers the surface of the padding 28 in the region that is in contact with the supporting plate 32 and with its supporting wings 44. Upon adjustment of the supporting plate 32 relative to the seat part 30, the supporting plate 32 moves relative to the padding 28. The slide surface 52 facilitates this relative movement. In the region of the front edge of the seat, the padding 28 is not connected with the mechanical carrier structure. An elastic part 54, for example a rubber band, is sewn in the border of the covering 26. Alternatively, the border is connected to the mechanical carrier structure through springs, rubber strips or the like. As a result, the border is allowed to move relative to the supporting plate 32. Upon adjustment of the seat depth, the edge of the covering 26 is displaced, although it always remains beneath the seat pan. As a result, other areas of the covering form the foremost upper padding edge, depending on the position of the supporting plate 32. In the region located behind the supporting plate 32, in particular in the region of the spring system 50, the padding 28 is connected, according to prior art, to the seat part 30 and so on, since there is no relative movement in this region. The limit between normal covering and movable covering is approximately in a line parallel to the y axis that passes through the basis of the U-shaped recess of the seat part 30. It is also possible to connect the side parts 38 to the padding 28.

The seat part 30 may also be configured differently from the configuration shown. It is illustrated as a cushion shell, but may also be configured to be a half shell or a simple front crossbeam.

In another embodiment, as shown in, FIG. 5, the supporting wings 44 are realized by U-shaped parts made from a metal or a plastic tube. The free ends of the legs are connected to the supporting plate 32. The legs are resilient and fit against the seat part 30 thanks to their intrinsic elasticity.

In the embodiment shown in FIG. 6, the supporting wings 44 are made from two bars each, said bars being also fixed to the supporting plate 32. At their free ends, they engage openings 56 that are provided in the seat part 30 for this purpose. Upon adjustment, there is a relative movement between each opening 56 and the bars forming the supporting wings 44.

Claims

1. A motor vehicle seat with a seat pan comprising:

a seat part and a supporting plate, said supporting plate being connected to the seat part via a guide for displacement in a longitudinal direction and comprising a front region forming the front edge of the seat pan, wherein said supporting plate comprises a left and a right supporting wing and the left supporting wing forms the left front corner and the right supporting wing forms the right front corner of the seat pan.

2. The motor vehicle seat as defined in claim 1, wherein the supporting wings are connected either to the supporting plate in a respective pivot joint or directly to the supporting plate.

3. The motor vehicle seat as defined in claim 1, wherein the supporting wings are configured to be elastic.

4. The motor vehicle seat as defined in claim 1, wherein a hand or motor driven adjustment device for adjustment in the longitudinal direction is provided between the seat part and the supporting plate.

5. The motor vehicle seat as defined in claim 1, wherein the supporting wings have a free end and that said free end fits laterally against the seat part, a slide means being provided between the free end and the seat part.

6. The motor vehicle seat as defined in claim 1, wherein each supporting wing has a free end and that said free end substantially points backward in the longitudinal direction.

7. The motor vehicle seat as defined in claim 1, wherein the seat part comprises left and right lateral slide surfaces or guide surfaces for abutment of the respective one of the supporting wings.

8. The motor vehicle seat as defined in claim 1, wherein the seat part comprises two openings and that one supporting wing engages in each opening.

9. The motor vehicle seat as defined in claim 1, wherein the seat part has a seat part width and the supporting plate has a width that is maximally about 80% of the seat part width.

10. The motor vehicle seat as defined in claim 1, wherein the seat pan includes a padding a portion of which is located above the supporting plate and that, upon adjustment of the supporting plate in the longitudinal direction, the supporting plate moves together with its supporting wings relative to the padding.

11. The motor vehicle seat as defined in claim 9, wherein the padding comprises a slide surface on its underside turned toward the supporting plate.

12. The motor vehicle seat as defined in claim 9, wherein the seat pan further comprises a covering that is located outside of the padding that it covers and has an end region that is located underneath the supporting plate, wherein the end region is elastically retained and is not directly connected to the supporting plate.

13. The motor vehicle seat as defined in claim 10, wherein the seat pan further comprises a covering that is located outside of the padding that it covers and has an end region that is located underneath the supporting plate, wherein this end region is elastically retained and is not directly connected to the supporting plate.

14. The motor vehicle seat as defined in claim 12, wherein the end region comprises an elastic part.

15. The motor vehicle seat as defined in claim 13, wherein the end region comprises an elastic part.

16. The motor vehicle seat as defined in claim 1, wherein the supporting plate comprises a first insertion opening on one seat side and the seat part has a mating second plug-type projection on this seat side or the supporting plate comprises a first plug-type projection on one seat side and the seat part has a mating second insertion opening on this seat side.