GB2042061A

GB2042061A - Device for regulating the position of a movable element in a vehicle such as the seat structure of the latter

Info

Publication number: GB2042061A
Application number: GB8001713A
Authority: GB
Original assignee: Compagnie Industrielle de Mecanismes CIM
Current assignee: Compagnie Industrielle de Mecanismes CIM
Priority date: 1979-01-24
Filing date: 1980-01-18
Publication date: 1980-09-17
Also published as: FR2447494B1; IT1129061B; IT8067098A0; FR2447494A1; DE3002500A1; ES488556A0; ES8102939A1; JPS5625028A

Abstract

The device comprises a screw jack (1) connected between a fixed point (5) of the body of a vehicle and a point (3) rigid with the movable element. The screw jack (1) comprises at least three telescopic members (6, 7 and 8) having respective interengaged screwthreads (11, 16 and 15, 19) which are in opposite directions. A driving device (20) is drivingly connected by a pulley and belt drive 23 to an intermediate member (7) of the screw jack (1) and is movable in translation with the intermediate member (7) in a direction parallel to the axis (X-X) of the jack (1). The screw jack 1 may be operated by a handle 31 or by an electric motor (not shown). <IMAGE>

Description

SPECIFICATION Device for regulating the position of a movable element in a vehicle such as the seat structure of the latter The present invention relates broadly to a device for regulating the position of movable elements in an automobile or like vehicle, such as for example the sliding roof, the hatchback or the lid of a rear luggage compartment.

More particularly, the machine concerns a device for regulating the position of a seat structure of such a vehicle.

Whatever be the seat structure or other movable element of the aforementioned type, there is posed a particular problem in automobile vehicles if it is desired to make it possible to adjust these elements conveniently and even by means of a motor.

Indeed, although in most cases the resistance to movement of the element, that is to say the blocking of the latter in a position chosen by the user, may be low in normal operation, namely at a few dozen kilograms for example, it must be several tons in the case of in particular a head-on shock on the vehicle. This problem arises especially in respect of seat structures of automobile vehicles.

Up to the present time, there have been used for adjusting these seat structures parallel racks which are fixed to the floor of the vehicle and a mechanism having moving pawls which are engaged with, or disengaged from, the racks by a simple lever. In this case, the resistance to forces in the event of an accident may be easily produced by choosing appropriate dimensions for the pawls and racks.

However, the regulation of the position of the seat structure is then discontinuous and mainly depends on the pitch of the rack which, owing to the resistance required of the latter, may not be as fine as one might desire.

Devices have also been developed for regulating the position of a seat structure of an automobile vehicle in which there are also employed racks which are engaged with gear pinions mounted on a shaft driven by an electric motor. The advantage of this device is that it permits a continuous regulation of the position of the seat structure but, on the other han*d, the motor and the transmission pinion or pinions must be so desired as to possess the aforementioned high mechanical resistance (see in particular French patent N" 2,388,694). Moreover, such a device has a relatively great overall height, whereas it is usually desired to place the seat of an automobile vehicle seat structure as low down as possible.

An object of the invention is to provide a device for regulating the position of a movable element, such as a seat structure in a vehicle, wherein this regulation is continuous and has a low overall height and permits resisting the considerable forces arising in the event of shocks on the vehicle.

According to the invention, there is provided a device for regulating the position of a movable element in a vehicle, in particular an automobile vehicle, relative to the body of the latter, in particular for regulating the position of a seat structure, said device comprising a screw jack having at least three telescopic members the respective screw-threads of which are of opposite direction, wherein said screw jack is connected between a fixed point of the body of the vehicle and a point rigid with the movable element and a device for driving in rotation is drivingly connected to an axially movable intermediate member of the screw jack and is movable with said intermediate member in translation in a direction parallel to the axis of the jack.

In this way the driving device, which may be manual or provided with a driving motor preferably of the electric type, is never stressed by the force exerted on the screw jack by the seat structure or like element itself, this force being, on the contrary, wholly transmitted from one end of the jack to the other, to the two fixing means by means of which the jack is fixed to the body and the movable element respectively.

Further features of the invention will be apparent from the ensuing description which is given solely by way of example with reference to the accompanying drawings in which: Figure 1 is a plan view, partly in horizontal section, of a manually actuated regulating device according to the invention applied more particularly to an automobile vehicle seat structure; Figure 2 is a view similar to Fig. 1 of another regulating device according to the invention actuated by a motor; Figure 3 is a side elevational view of the device of Fig. 2, and Figure 4 is a cross-sectional view taken on line 4-4 of Fig. 2.

Fig. 1 shows a regulating device according to the invention used for moving an automobile vehicle seat structure, this being a particularly suitable application of the invention, although other movable elements in a vehicle may also be provided with a regulating device.

The regulating device comprises a screw jack which is adapted to be mounted in the vehicle in the longitudinal direction and has a front end 2 adjacent to the front of the vehicle (left side of Fig. 1).

This front end 2 is fixed to connecting means 3 of any suitable type rigid with the seat of the seat structure (not shown) of the vehicle.

The opposite end 4 of the screw jack 1 is fixed, also by connecting means 5 of any suitable type, to the floor of the vehicle.

in the illustrated embodiment, the screw jack 1 comprises three distinct members 6, 7 and 8 which are telescopically engageable one inside the other and define an axis X-X parallel to the direction of movement of the seat structure. The front member 6 which has the largest diameter is formed by a sleeve 9 having a closed end which terminates in a fixing tab 10. Its opposite end has a screwthreaded portion 11 in which there is screwthreadedly engaged the second member 7 or intermediate member of the screw jack. The second member 7 is of tubular shape and its rear part has externally a splined portion 1 3 which terminates at both ends in axially extending shoulders 14.The rear part 1 2 of the intermediate member 7 has an internal screwthreaded portion 15, the screwthread being in the opposite direction to the outer screwthread 1 6 of the intermediate member 7 which is screwthreadedly engaged with the screwthreaded portion 11 of the first member 6.

The third member 8 of the jack 1 is formed by a screwthreaded rod 1 7 which terminates in a fixing tab 1 8 and has a screwthread 1 9 which is adapted to the internal screwthread 1 5 of the rear portion 1 2 of the intermediate member 7.

The regulating device shown in Fig. 1 further comprises a driving device 20 which is actuated manually in this embodiment. This driving device 20 comprises two pulleys, one of which is the splined portion 1 3 of the intermediate member 7 whereas the other pulley 21 is rigid with a square-section rod 22 whose axis Y-Y is parallel to the axis X-X.

The pulleys 1 3 and 21 are interconnected by a toothed belt 23, the assembly thus formed being mounted in a case 24 which is maintained axially in position by the shoulders 14 of the intermediate member 7. It will be understood that a driving device may be provided which comprises gear pinions instead of the pulleys and belt just described.

A A support element 25 is rigidly fixed by a first collar 26 to the first member 6 of the screw jack 1 and by a second collar 27 to a driving and guiding sleeve 28, the two collars being rendered rigid with each other by a connecting arm 29. The sleeve 28 is disposed in alignment with the square-section rod 22 and has a longitudinally extending passage 30 of corresponding shape and a wheel or crank 31 is secured to its front end.

When the wheel 31 is rotated, the intermediate member 7 is driven in rotation and this causes the screw jack 1 to shorten or lengthen, corresponding to a greater or smaller penetration of the rod 22 in the sleeve 28. The axial travel of the members 7 and 8 may be limited by the ends of the screwthreads of these members and the full extension of the jack may be if desired limited by end-of-travel stops (not shown).

The axial force required for moving the seat structure is solely transmitted through the jack between the fixing points formed by the connecting means 3 and 5 and the driving device 20 does not participate in the transmission of this axial force since it moves with the intermediate member 7.

On the other hand, with the seat structure adjusted in a given position and a high deceleration of the vehicle, for example upon a head-on shock which tends to project the seat structure forwardly, the resulting force F exerted on the regulating device shall be transmitted solely through the screw jack 1 to its rear fixing point rigid with the floor of the vehicle. Moreover, note that, in the preferred illustrated arrangement, the screw jack then tends to be extended by this force owing to the fact that its front end is fixed to the seat structure. The opposite arrangement which would tend to shorten the jack would increase the risk of buckling.

Figs. 2 to 4 show another embodiment of the regulating device. A seat structure, whose seat A is shown diagrammatically, rests on two parallel slideways G of conventional design (the Figures show only one of these slideways). The fixed part Gf of each slideway is anchored tQ the floor of the vehicle (the rear end of the screw jack 1) and the movable part Gm is rigid with the seat A.

The screw jack 1 of the regulating device is of a type almost identical to that of the jack of Fig. 1 and like elements carry like reference characters. However, note that in this embodiment the member 6 of largest diameter is located at the rear (and is consequently rigid with the floor of the vehicle) whereas the screwthreaded rod 1 7 of the third member 8 is rigid with the seat through the movable slideway Gm as shown in Fig. 4 and with a connecting tab 32 similar to the connecting means 5 of Fig. 1. It will be understood that this reverse arrangement mechanically corresponds to a mere equivalent and changes nothing as concerns the operation of the regulating device and the advantages afforded by the latter.

The regulating device of Figs. 2 to 4 differs from that of Fig. 1 in the following respects: The first member 6 of the screw jack is constructed in the form of a tubular sleeve 33 obtained by deforming sheet metal. Inserted in this sleeve is a bush 34 which is internally screwthreaded and rigid with the sleeve by deformed portions 35 in the sheet metal.

Further, the sleeve 33 has an outer bead which extends longitudinally throughout its length.

The regulating device also comprises a driving device 37 which is in this case actuated by an electric motor 38 which is connected to move in rotation and in translation with the intermediate member 7 of the screw jack.

The motor 38 comprises a case 39 which has a front cavity 40 in which is mounted a speed reducer 41 having pulleys and belts.

The cavity 40 of the case surrounds the intermediate member 7 of the screw jack 1 and is retained axially relative to the intermediate member 7 by shoulders 42 which are provided at each end of the splined portion 1 3 of this intermediate element. A belt 43 ensures the connection with the output pulley of the motor-speed reducer 38-41.

The case 39 of the latter is also rigid with a collar 44 through a tab 45, the collar surrounding the sleeve 43 of the first member 6 of the screw jack so as to be slidable thereon.

The collar 44 comprises an inner axial groove 46 which fits the shape of the bead 36 of the sleeve 33. Thus the driving device 37 is prevented from turning about the axis X-X but is movable in translatiqn along this axis.

The device of Figs. 2 to 4 operates in an identical manner to that of the embodiment of Fig. 1 except that it is actuated by a motor. It affords the same advantages and in particular the independence of the driving device from the screw jack as concerns the exceptional force to be transmitted between the fixing points in the event of violent shocks.

Note that the regulating device according to the invention has a very small overall height which hardly exceeds the height of the slideways of the seat structure (see in particular Fig. 4).

The invention is not intended to be limited to the embodiments just described which concern an application to vehicle seat structures.

Indeed, the regulating device may serve to shift and position any structure relative to another, even outside the vehicle when the movable element of this structure is liable to be subjected occasionally to forces which are much greater than the normal force to be overcome when moving the structure.

Thus, other applications are for example the modification of the height of the seat of vehicle seat structures instead of the longitudinal position of these seat structures (these two adjustments may moreover be combined by two regulating devices according to the invention), the opening of the hatchback of a vehicle, etc.

Claims

1. A device for regulating the position of a movable element in a vehicle, in particular an automobile vehicle, relative to the body of the latter, in particular for regulating the position of a seat structure, said device comprising a screw jack having at least three telescopic members the respective screw-threads of which are of opposite direction, wherein said screw jack is connected between a fixed point of the body of the vehicle andj a point rigid with the movable element and a device for driving in rotation is drivingly connected to an axially movable intermediate member of the screw jack and is movable with said intermediate member in translation in a direction parallel to the axis of the jack.

2. A device as claimed in claim 1, wherein the end of the screw jack corresponding to the front of the vehicle in which this jack is mounted is attached to the movable element.

3. A device as claimed in claim 1 or 2, wherein said intermediate member is of tubular shape and screwthreaded at least partly internally and externally, said intermediate member has a portion defining annular shoulders and said device for driving in rotation is disposed in a case which is driven in translation along said axis by said annular shoulders.

4. A device as claimed in claim 3, further comprising a device for guiding said case in translation.

5. A device as claimed in claim 4, wherein said guiding device comprises a telescopic assembly of a rod and a sleeve, said assembly being connected between one of the fixing points of the jack and said case in a position parallel to the axis of the jack, the sleeve and the rod being connected to rotate together and coupled to an actuating device.

6. A device as claimed in claim 4, wherein said guiding device comprises a guide member which is rigid with said case and surrounds one of the members of the screw jack on which one member said guide member is guided in translation, means are provided for preventing said guide member from turning about said one member of the jack and said driving device is coupled to an actuating device.

7. A device as claimed in claim 5 or 6, wherein said actuating device is formed by a manually rotated wheel or by an electric or other motor.

8. A device for regulating the position of a movable element in a vehicle, substantially as hereinbefore described with reference to and as shown in Fig. 1 of the accompanying drawings.

9. A device for regulating the position of a movable element in a vehicle, substantially as hereinbefore described with reference to and as shown in Figs. 2 to 4 of the accompanying drawings.