GB2081082A

GB2081082A - Seats

Info

Publication number: GB2081082A
Application number: GB8120773A
Authority: GB
Original assignee: Rentrop Hubbert & Wagner
Current assignee: Rentrop Hubbert & Wagner
Priority date: 1980-07-21
Filing date: 1981-07-06
Publication date: 1982-02-17
Also published as: SE8104382L; ES8301780A1; ES504098A0; IT1148090B; BR8104656A; DE3027560A1; BE889669A; ZA814826B; JPS5747226A; FR2486788B1; IT8185592A0; FR2486788A1

Abstract

A vehicle seat has a seat part (1) supported on an underframe (2) by a system of linkages including two rotary rods (13 and 14) located respectively along the front edge and rear edge of the seat part (1), of which carries a pair of bell crank levers (3,4 and 5,6) which are at their first ends pivotally connected to respective supports (7,8 and 9,10) rigid with the seat part (1), while the other ends (4a and 6a) are coupled to respective thrust mechanisms (21 and 25). In an alternative both adjustment means are driven from the same motive power source. <IMAGE>

Description

SPECIFICATION Seats The present invention relates to seats, for example vehicle seats.

Previously proposed vehicle seats have incorporated a device for changing the position of the seat part relative to the underframe of the seat. In one construction there are mounted in the region of the front edge of the seat part and correspondingly at the rear edge of the seat part two actuating devices in the form of elevating mechanisms. Thus a total of four devices are provided wth each pair of elevating mechanisms being driven by a motor. If the corresponding motor is set into operation, then the forward edge and/or the rearward edge of the seat part is respectively raised up or lowered, as a result of which a stepless adaptation of the position of the seat relative to the underframe of the seat is possible corresponding to the shape and size of the body of the vehicle occupant.High costs al'ise because of the use of four elevating mechanisms as well as the associated two drive motors.

According to the invention, there is provided a seat, comprising a seat part, an underframe and a system of linkages adjustably supporting the seat part on the underframe, the system comprising a first pair of pivotal levers pivotally connected to supports on the underside of the seat part in the region of the forward edge of the seat part and a second pair of pivotal levers pivotally connected to supports on the underside of the seat part in the region of the rearward edge of the seat part, a rotary shaft interconnecting the pivotal lever of each pair, one lever of each pair being in the form of a bell crank having one arm coupled to a respective support, and mechanically actuated thrust means having push rod means coupled to the other arm of each bell crank to displace the pivotal levers and thereby effect adjustment of the seat part with respect to the underframe.

According to the invention, there is further provided a seat comprising an underframe, a seat portion, first and second rotary shafts supported on the underframe so that their rotary axes extend parallel to one another but lie spaced apart in a horizontal direction, a pair of axially spaced arms rigid with each shaft, the pair of arms rigid with the first shaft being pivotally coupled to the seat portion in the region of the front edge thereof and the pair of arms rigid with the second shaft being pivotally coupled to the seat portion in the rear edge thereof, a second arm rigid with each shaft and thrust means for displacing each arm about the axes of a corresponding shaft to effect adjustment of the seat portion relative to the underframe.

Vehicle seats embodying the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a vertical section through one of the vehicle seats; Figure 2 is a partial plan view of the seat of Figure 1, with the seat portion omitted; and Figures 3 and 4 are fragmentary side elevations of another one of the seats in two different operative positions.

The vehicle seat shown in Figure 1 has a seat part 1 defining a front edge la and a rear edge 1b, and incorporating a frame 1c. The securing of the seat to the floor of the vehicle is effected through the underframe 2, for example in the form of support rails or longitudinal adjustment rails.

A pair of pivotal levers 3 and 4 is arranged in the region of the front edge la of the seat part 1. The pivotal lever 3 is in the form of a single-armed lever, while the pivotal lever 4 is in the form of a bell-crank.

Also in the region of the rear edge ib of the seat part 1, two pivotal levers 5 and 6 are provided, the pivotal lever 6 being in the form of a bell-crank.

The pivotal levers 3 to 6 are pivotally connected to respective ones of supports 7 to 10 rigid with the underside ofthe seat part 1; link straps 11, 12, provide the connections in the case of the pivotal levers 3 and 4 but these can be omitted if desired.

Each pair of pivotal levers 3 and 4 and 5 and 6 are rigidly interconnected by a respective one of two rotary shafts 13 and 14. The shafts 13 and 14 are supported in a respective one of two pairs of bearing blocks 15 and 16 or 17, 18 for rotation about respective axes extending transversely to the longitudinal axis ofthe seat part 1; t e axes being spaced from one another. These beating blocks 15, or 16or17, 18 are supported on the underframe 2 in the form of support rails or adjustment rails of the seat.

A drive motor 19, is arranged to transmit rotational motion through a shaft 20 to a displacement or thrust device 21. By this means a push rod 22 can be displaced in and out in a rectilinear direction depending upon the sense of rotation. The rod 22 is pivotally connected to an arm 4a of the bell crank 4. Since displacement devices of this kind are known in themselves in various constructional forms, further details are omitted.

A drive motor 23 associated with the rear edge 1b of the seat part, is arranged to actuate a thrust device 25 through the shaft 24, to cause a two-part push rod 26, 27 to be displaced in the horizontal direction. The first part 26 of the push rod 26, 27 is connected to the second part 27 by a pivot 28, and the second part 27 is pivoted to an arm 6a of the bell crank lever 6.

If the seat part 1 is to be raised parallel to itself, then both drive motors 19,23 are set in operation, to actuate the thrust devices 21, 25 through the shafts 20, 24 and to cause the push rods 22 and 26,27 to be moved outwardly. By this means the bell crank lever 4 is rotated in a clockwise sense, while the lever 6 executes a rotational movement in an anti-clockwise sense. The result is that by the corresponding pivoting of the arms connected to the supports 7 to 10, both pivotal levers 6 and 7 raise the seat part parallel to itself. The lowering of the seat part 1 is effected in a similar manner.

If only the forward edge 1a of the seat part is to be raised, then only the drive motor 19 is actuated, The drawing(s) originally filed was/were informal and the print here reproduced is taken from a later filed formal copy.

while during mere raising or respectively lowering of the rear edge 1b of the seat part only the drive motor 23 is set into operation. With this adjustment device the seat part 1 can also be adjusted as follows: Raising or respectively lowering of the forward edge of the seat part and/orofthe rearward edge of the seat part.

In the vehicle seat shown in Figures 3 and 4, parts similar two those of Figures t and 2 are similarly referenced. The main difference between the seat of Figures 3 and 4 and that of Figures 1 and 2 is that in the seat of Figures 3 and 4 the arms 4a and 6a of the bell crank levers 4 and 6 are driven by a common push device 29, instead of by separate push devices. The push device 29 is driven by a drive motor (not shown). Furthermore, the two arms 4a, 6a lie in a plane parallel to the longitudinal central plane of the seat part 1 and are interconnected by a link rod 30, to which one part of the two part push rod 31,32 of the thrust device 29 is pivoted. The pivot point is thus the pivot 33. The first part 32 of the push rod is connected to the second part 31 by a pivot 34.

Since the manner of operation of the seat adjustment device is apparent from the drawings and the description further details are omitted. In this adjustment device only a single drive motor and a single push device 29 are used. An independent raising or respectively lowering of the forward edge la of the seat part is not possible and so the seat part can only be raised or lowered parallel to itself.

In the described vehicle seats the levers of each pair of pivotal levers are interconnected by means of a rotatably mounted shaft, the one lever of any given pair of levers being in the form of a bell crank lever and one arm of each bell crank lever being driven by a push rod of a mechanically-actuated displacement device.

Preferably, the rotatable shaft of each pair of pivotal levers is mounted in two bearing blocks spaced from one another and extending transversely to the longitudinal direction of the seat part, which bearings are supported against the underframe of the seat.

In a first embodiment with direct drive of the second arm ef each bell crank lever the push rod of a respective displacement device is linked to the second arm of the bell crank lever. Therefore, preferably, the push rod of the displacement device is divided in the region of the rear edge of the seat part, the second part linked to the second arm ofthe bell crank lever being in connection with the first part through a link.

Because only two displacement devices are used overall with two drives, for example drive motors, this has its effect on the total weight, the costs and also the reliability of operation in a very favourable manner.

The number of the displacement devices as well as the drives can be still further substantially reduced, in that only a single displacement device and a single drive are necessary. These two are therefore interconnected by a link rod through arms lying in a plane parallel to the longitudinal central plane of the seat part, to which the one part of the divided push rod is linked to the displacement device.

Claims

1. A seat comprising a seat part, an underframe and a system of linkages adjustably supporting the seat part on the underframe, the system comprising: a first pair of pivotal levers pivotally connected to v- supports on the underside of the seat part in the region of the forward edge of the seat part and a second pair of pivotal levers pivotally connected to supports on the underside of the seat part in the region of the rearward edge of the seat part, a rotary shaft interconnecting the pivotal lever of each pair, one lever of each pair being in the form of a bell crank having one arm coupled to a respective sup port, and mechanically actuated thrust means having push rod means coupled to the other arm of each bell crank to displace the pivotal levers and thereby effect adjustment of the seat part with respect to the underframe.

2. A seat according to claim 1, wherein the thrust means comprises a pair of thrust devices each having a push rod coupled to a respective one of the bell cranks.

3. A seat according to claim 1, wherein the thrust means comprises a simple mechanicallfactuated thrust device having a push rod coupled to both bell cranks.

4. A seat according to any one of claims 1 to 3, wherein each rotary shaft is supported by bearing blocks so that its rotational axis extends transversely to the longtiudinal direction of the seat part, the two rotational axes being spaced from one another in said longitudinal direction.

5. A seat according to claim 2, wherein each push rod is directly pivotally connected to said other arm of a respective bell crank.

6. A seat according to claim 2, wherein the push rod coupled to the bell crank in the region of the rearward edge of the seat part is constructed in two parts, one part being pivotally connected at one end portion to the said other arm of the bell crank and being pivotally connected at the other end portion to the other part.

7. A seat according to claim 3, wherein the said other arms of the two bell cranks are interconnected by a link rod lying in a plane extending parallel to the longitudinal central plane of the seat part, the link rod being pivotally connected to the push rod.

8. A seat according to claim 7, wherein the push rod is in two parts, one part being pivotally connected both to the link rod and to the other part.

9. A seat comprising an underframe, a seat portion, first and second rotary shafts supported on the underframe so that their rotary axes extend parallel to one another but lie spaced apart in a horizontal q direction, a pair of axially spaced arms rigid with each shaft, the pair of arms rigid with the first shaft being pivotally coupled to the seat portion in the region of the front edge thereof and the pair of arms rigid with the second shaft being pivotally coupled to the seat portion on the rear edge thereof, a second arm rigid with each shaft and thrust means for displacing each arm about the axes of a corresponding shaft to effect adjustment of the seat portion relative to the underframe.

10. A seat according to claim 9, wherein each second arm and one arm of the corresponding pair of arms together form a bell crank.

11. A vehicle seat substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.

12. A vehicle seat substantially as hereinbefore described with reference to Figures 3 and 4 of the accompanying drawings.