GB2301281A

GB2301281A - Adjustable vehicle seat

Info

Publication number: GB2301281A
Application number: GB9610852A
Authority: GB
Inventors: Yukifumi Yamada
Original assignee: Aisin Seiki Co Ltd
Current assignee: Aisin Corp
Priority date: 1995-05-24
Filing date: 1996-05-23
Publication date: 1996-12-04
Anticipated expiration: 2016-05-23
Also published as: GB2301281B; GB9610852D0

Abstract

A slidable vehicle seat with height adjustment has a pair of lower rails 13 (14, Fig 1) upon which slide a pair of upper rails one of which 11 carries a bracket 31 in which is rotatably supported a shaft 32. The other end of the shaft is supported in the other upper rail. A sector gear 33 fixed to the shaft is driven by a handle 36 via gear 37 both also mounted on the bracket. Gear 33 is connected via link 342 to bell-crank 341 which is pivoted to the rail 11 and also connected to the seat to provide height adjustment. A similar link and crank are fixed to the other upper rail and this link is connected to a further link (352, Fig 3) fixed to the other end of the shaft.

Description

TITLE Seat Apparatus DESCRIPTION Field of the Invention The present invention generally relates to a seat apparatus, particularly apparatus for raising and lowering the seat cushion of a vehicle seat.

Background of the Invention A seat apparatus is disclosed in Japanese Utility Model laid-open publication No. 4-37026.

This seat apparatus includes a seat cushion, a pair of lower rails, a pair of upper rails, a rotary shaft, a sector gear, a driving mechanism and a pair of link mechanisms. The lower rails are secured to a floor of a vehicle. The upper rails are slidably supported on the lower rails. Both ends of the rotary shaft are rotatably supported by the upper rails. The sector gear is secured to the rotary shaft. The driving mechanism is supported on one of the upper rails and connected with the sector gear. The link mechanisms are connected to the rotary shaft and to side portions of the rear end of the seat cushion.

When the driving mechanism is driven, the rotary shaft is rotated through the sector gear, moving the pair of link mechanisms. As a result, the rear end of the seat cushion is lifted relative to the floor of the vehicle.

However, in this case, one of the upper rails is larger with a different shape from the other upper rail because a supporting portion which supports the driving mechanism is formed on one of the upper rails. As a result, the seat apparatus is hard to produce and increased in cost.

SUMMARY OF THE INVENTION A need exists, therefore, for a seat apparatus which addresses at least the foregoing drawbacks of the prior art.

According to the present invention, a seat apparatus comprises a seat cushion, a pair of lower rails secured to a floor of the vehicle, a pair of upper rails slidably supported on the lower rails a bracket which is secured to one of the upper rails, a rotary shaft which is rotatably supported on the bracket and the other of the upper rails, a sector gear which is secured to the rotary shaft, a driving mechanism which is supported on the bracket and connected to the sector gear and a link mechanism which is connected to the sector gear and the seat cushion.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and additional features of the present invention will become more apparent from the following detailed description of the preferred embodiment thereof when considered with reference to the attached drawings, in which: Fig. 1 is a perspective view of a seat apparatus according to the present invention; Fig. 2 is a side view from direction II in Fig. 1; Fig. 3 is a side view from direction III in Fig. 1, reversed laterally for ease of comparison with Fig. 2; and Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter a seat apparatus according to an embodiment of the present invention is explained with reference to Fig.

1, Fig. 2, Fig. 3 and Fig. 4.

As shown in Fig. 1, the seat apparatus comprises a seat cushion 4, a seat back 5, a seat sliding mechanism 1, a seat reclining mechanism 2 and seat lifting mechanism 3.

The seat sliding mechanism 1 slides the seat cushion 4 and the seat back 5 in the direction of the front or rear of a vehicle relative to a floor 6 of the vehicle. The seat reclining mechanism 2 inclines the seat back S relative to the seat cushion 4. The seat lifting mechanism 3 lifts the rear end of the seat cushion 4 relative to the floor 6 of the vehicle.

As shown in Fig. 1, Fig. 2 and Fig. 3, the seat sliding mechanism 1 comprises the first and second upper rails 11,12 and the first and second lower rails 13,14. The first and second lower rails 13,14 are secured in parallel to the floor 6 of the vehicle through brackets 7. The first and second upper rails 11,12 are slidably supported on the first and second lower rails 13,14, respectively.

The first and second upper rails 11,12 have the cross-sectional shape of an inverted 'T' with vertical flange portions lla,12a.

The seat reclining mechanism 2 comprises first and second lower arms 21,22 and first and second upper arms 23,24.

The first and second lower arms 21,22 are secured to the vertical flange portions lla,12a of the first and second upper rails 11,12. The first and second upper arms 23,24 are secured to the side portions of lower end of the seat back 5 and rotatably supported on the first and second lower arms 21,22 by pins 25.

The lifting mechanism 3 comprises a bracket 31, a rotary shaft 32, a sector gear 33, a pair of link mechanisms 34,35, a driving mechanism 36 and an intermediate gear 37.

The bracket 31 extends vertically and is secured to a front end of the flange portion 11a of the first upper rail 11 by pins 31a,31b. The rotary shaft 32 extends transversely across the vehicle from left to right and is positioned below the seat cushion 4.

One end 32a of the rotary shaft 32 is rotatably supported by the bracket 31 and extends through the flange portion lla of the first upper rail 11. The other end 32b of the rotary shaft 32 is rotatably supported by the flange portion 12a of the second upper rail 12. The sector gear 33 is secured to the rotary shaft 32 near the end 32a so as to be integrally rotated with the rotary shaft 32.

The link mechanism 34 comprises a bell-crank link 341 and a connecting link 342. The bell-crank link 341 is rotatably supported on the flange portion lla of the upper rail 11 by a pin 341a. One end of the bell-crank link 341 is mounted on the side portion of the rear end of the seat cushion 4. The connecting link 342 extends from the sector gear 33 to the bell-crank link 341 and is generally parallel to the upper rail 11. One end of the connecting link 342 is rotatably connected to the sector gear 33.

The other end of the connecting link 342 is rotatably connected to the other end of the bell-crank link 341.

The link mechanism 35 comprises a bell-crank link 351, a first connecting link 352 and a second connecting link 353. The bell-crank link 351 is rotatably supported on the flange portion 12a of the upper rail 12 by a pin 351a which is in coaxial relationship with the pin 341a. The first connecting link 352 is secured to the rotary shaft 32 near the end 32b so as to be integrally rotated with the rotary shaft 32 when the sector gear 33 is rotated.

The second connecting link 353 extends from the first connecting link 352 to the bell-crank link 351 and is generally parallel to the upper rail 12. One end of the second connecting link 353 is rotatably connected to the first connecting link 352, at the same spacing from the axis of the shaft 32 as is the corresponding end of the connecting link 342. The other end of the second connecting link 352 is rotatably connected to the other end of the bell-crank link 351.

The driving mechanism 36 comprises a handle 361, a brake mechanism 362 and a pinion gear 363. The brake mechanism 362 is arranged on the outer face 312 of the bracket 31 and comprises a case 362a housing an input shaft member 362b, an output shaft member 362c and a coil spring 362d.

The case 362a is fixed on the outer surface 312 of the bracket 31. The handle 361 is fixed to the input shaft member 362b. The input shaft member 362b is rotatably supported between the case 362a and the bracket 31. The output shaft member 362c is rotatably supported on the input shaft member 362b.

Each end of the coil spring 362d is located between an upstanding portion of the input shaft member 362b and an upstanding portion of the output shaft member 362c. When the input shaft member 362b is rotated by the handle 361 in either direction, it engages an end of the coil spring 362d so as to increase the number of turns on the spring.

The coil spring 362d is thereby released from frictional engagement with the interior of the case 362a and the rotation of the input shaft member 362b causes the output shaft member 362c to rotate. When the torsion in the coil spring 362d is relaxed, the coil spring 362d is again frictionally engaged with the case 362a. If the output shaft member 362c is urged to rotate when the handle 361 is not turned, for example when a person sits on the seat cushion 4, the output shaft member 362c engages an end of the coil spring 362d so as to decrease the number of turns on the spring. The coil spring 362d thereby frictionally engages the case 362a more strongly and prevents the output shaft member 362c from rotating.

The pinion gear 363 is integrally formed with the output shaft member 362c of the brake mechanism 362. A notched flange 313 is integrally formed on the bracket 31 so as to project in the inward direction. The pinion gear 363 is engaged by the teeth on the intermediate gear 37 through the notch in the flange 313. The intermediate gear 37 is rotatably mounted on the inner surface 311 of the bracket 31 by a pin 37a. The intermediate gear 37 has a large diameter circle of gear teeth 371 engaging the pinion gear 363 of the driving mechanism 36, and a small diameter circle of gear teeth 372 engaged with the sector gear 33.

The pin 37a is secured to the bracket 31, and the intermediate gear is secured to the pin 37a by a split pin 37b and a washer 37c. The sector gear 33 engages the small diameter circle of gear teeth 372 between the large diameter portion 371 of the intermediate gear 37 and the washer 37c. Thereby, an axial movement of the sector gear 33 and the rotary shaft 32 is limited by the large diameter portion of the intermediate gear 37 and the washer 37c. As a result, the rotary shaft 32 does not require any supporting member. Thereby, a supporting mechanism of the rotary shaft 32 relative to the bracket 31 can be simplified.

In this embodiment, the rotary shaft 32 and the driving mechanism 36 are supported on the bracket 31, so that the seat lifting device 3 constitutes an integrated part assembled on the bracket 31. As a result, the first upper rail 11 of the seat sliding device 1 can be the same rail as the second upper rail 12 of the seat sliding device.

Furthermore, the handle 361 of the driving mechanism 36 may be replaced with a motor, in which case the brake mechanism 362 is not necessary.

Claims

1. A seat apparatus comprising: a seat cushion; a pair of lower rails to be secured to a floor of the vehicle; a pair of upper rails slidably supported on the lower rails; a bracket secured to one of the upper rails; a rotary shaft rotatably supported on the bracket and the other of the upper rails; a sector gear secured to the rotary shaft; a driving mechanism supported on the bracket and connected to the sector gear; and a link mechanism connected to the sector gear and the seat cushion.

2. Apparatus according to claim 1, further comprising: an intermediate gear rotatably supported on the bracket and engaged with the sector gear and the driving mechanism.

3. Apparatus according to claim 2, further comprising: a pin secured to the bracket, wherein the pin is a pivot of the intermediate gear; and a stopping member secured to the pin, wherein the stopping member limits axial movement of the intermediate gear and of the sector gear engaged with the intermediate gear.

4. Apparatus according to claim 3, wherein the sector gear is located between a portion of the intermediate gear and the stopping member.

5. A seat apparatus substantially as described herein with reference to the drawings.