WO2002085664A2

WO2002085664A2 - Seat including backrest movable with respect to seat part and moving device for use therein

Info

Publication number: WO2002085664A2
Application number: PCT/NL2002/000278
Authority: WO
Inventors: Johannes Theodorus Marie Rasenberg
Original assignee: WHIPLASH PREVENTIE SYSTEMS HOLDING NV
Current assignee: WHIPLASH PREVENTIE SYSTEMS HOLDING NV
Priority date: 2001-04-25
Filing date: 2002-04-25
Publication date: 2002-10-31
Anticipated expiration: 2003-10-25
Also published as: NL1018170C2; WO2002085664A3

Abstract

The invention relates to a vehicle seat, comprising a seat part (2) and a backrest (3) pivotally connected thereto, which backrest (3) is movable in relation to the seat part (2). The backrest (3) can herein define a main plane and be movable parallel to the main plane. The seat can further be provided with a head support connected movably to the backrest (3). The seat can also have means for detecting the position of the backrest (3) and/or the head support, means connected to the detection means for comparing the detected position to a desired position, and means connected controllably to the comparing means for displacing the backrest (3) and/or head support to the desired position. The seat can thus be adjusted automatically. The invention further relates to a device for moving the seat part (2) and the backrest (3) relative to each other which can be adapted to maintain a set angle between the seat part (2) and backrest (3) during movement of the seat part (2) or backrest (3). This device can comprise a gear system comprising two toothed wheels (35', 35'), each connected to one of the elements, and an intermediate (35) wheel placed between the toothed wheels (35', 35').

Description

SEAT INCLUDING BACKREST MOVABLE WITH RESPECT TO THE SEAT PART AND MOVING DEVICE FOR USE THEREIN

The invention relates to a seat, in particular a vehicle seat, comprising a seat part and a backrest pivotally connected thereto.

In seats which are used regularly, such as for instance vehicle seats, but also office chairs, the adjustability of the different components of the seat, such as the seat surface and the backrest, is of great importance. Such seats must after all support any user in optimal manner. In addition to obvious advantages such as improved seating comfort, whereby fatigue occurs less quickly and it is therefore possible to work or drive better and in more concentrated manner, in the case of vehicle seats the further aspect of improved safety is also an important issue. Particularly in the case of rear-end collisions the seat will have to cushion and protect the body of the passenger, for which purpose an optimum fit is very important.

This latter aspect is particularly important when the seat is provided with a safety mechanism as described in applicant's non-prepublished international patent application PCT/NL00/00074. For correct operation of the mechanism described therein, wherein in the case of a rear-end collision the upper part of the backrest pivots forward on a shaft while carrying with it the head support, the position of the shaft relative to the back of the user has to be precisely adjusted.

In the adjustment of the different components of a seat it is of further importance that the different adjustment options influence each other as little as possible, so that parameters such as the seating angle, seating height and so on can be set independently of each other to an optimum value. The invention herein makes use of existing planetary gears such as those marketed by the firm Bertrand Faure, which gear forms a closed adjustment mechanism which is widely applied in vehicle seats. The invention therefore provides a seat of the above described type wherein the backrest is movable in relation to the seat part. By thus causing the backrest not only to pivot relative to the seat part, but also to displace relative thereto, the form and dimensions of the seat can be adjusted in optimal manner to a user.

The backrest herein preferably defines a main plane and is movable substantially parallel to the main plane thereof. In this way the backrest can be displaced in its length direction, whereby persons of different posture can be optimally supported and protected. When the seat is provided with means for detecting the position of the backrest, means connected to the detection means for comparing the detected position to the desired position, and means connected controllably to the comparing means for displacing the backrest to the desired position, the adjustment of the seat can take place automatically without the intervention of the user. Thus is ensured that the seat supports and protects the user in the correct manner under all conditions. The detecting means and the comparing means can herein be integrated and formed by at least one transmitter/receiver unit connected to the backrest and at least one reflector arranged at a fixed point in the transmission range of the unit. By arranging the reflector for instance on the windscreen of the vehicle in the case of a vehicle seat, the position of the backrest can thus be determined in simple manner by whether or not the reflector is obstructed by the head of a passenger. According to another aspect of the invention the seat has a head support connected movably to the backrest, in addition to means for detecting the position of the backrest, means connected to the detecting means for comparing the detected position to the desired position, and means connected controllably to the comparing means for displacing the backrest to the desired position. An optimal position of the head support can thus also be ensured under all conditions, independently of the setting of the backrest. For height adjustment of the head support use can again be made here of a transmitter/receiver unit and a reflector which is covered by the head of the user when the head support setting is too low. In order to be able to maintain a correct distance between the head of the user and the head support, the detection means preferably comprise at least one distance measuring device directed at the head of the user.

The invention also relates to a device for moving relative to each other two elements pivotally connected to each other, which is suitable for use in a seat as described above. In a preferred embodiment this device is adapted to maintain a set angle between the elements during movement thereof. Once set, an optimal angle can thus be maintained when for instance a backrest of a seat is moved relative to the seat part, so that the position of the backrest does not have to be readjusted again every time the length of the backrest changes . In a preferred embodiment of the device one of the elements, the seat part, is fixed and the other element, for instance the backrest, is connected thereto for movement parallel to itself via at least one connecting member. The at least one connecting member can herein be rotatable, whereby a relatively simple construction is obtained. A connecting member which is slidable or displaceable in other manner can however also be envisaged.

A robust and structurally simple device can be provided with three mutually co-acting connecting members which together form a gear system. Using such a gear system the desired movement of for instance the backrest can be realized in simple manner, while such a gear system is furthermore highly suitable for a possible combination with the pivot mechanism between the two elements. The gear system can herein also comprise at least two toothed wheels, each connected to one of the elements, and at least one intermediate wheel placed between the toothed wheels. An alternative embodiment of the device has four mutually co-acting connecting members which together form a linkage. In order to keep the angle between the elements constant during a movement, the linkage is preferably a parallelogram. The device can further display operating means which co-act with the at least one connecting member and with which the mutual displacement of the elements can be effected.

When the device is further provided with a mechanism for adjusting the angle between the elements, this adjusting mechanism is preferably connected controllably to the operating means for the movement. In this manner both the angle between the elements and the mutual position of the elements can be adjusted with a single control.

The operating means are herein advantageously movable between a position in which they engage the connecting member and a position in which they engage the adjusting mechanism. It is thus possible in simple manner to switch between a pivoting movement and a displacement of the elements. Here the device preferably has means for biasing the operating means to one of the positions, so that they have a preferred position. This will generally be the position in which the operating means engage the adjusting mechanism, since the angle between the elements will be adjusted more frequently than the relative position thereof.

The device is preferably further provided with means for locking the operating means in at least one of the positions. The operating means can thus be prevented from unexpectedly moving to another position, whereby the use of the operating means could thus have an undesirable result.

The invention is now elucidated on the basis of a number of embodiments, wherein reference is made to the annexed drawing, in which:

Fig. 1 shows a partly cross-sectional perspective view of a vehicle seat with a backrest movable in relation to the seat part and a device for moving the backrest according to the invention,

Fig. 2 is a side view of the essential components of the moving device in different positions,

Fig. 3 is a perspective view of the essential components of the moving device and the operating means connected thereto,

Fig. 4 is a view corresponding with fig. 3 of the moving device when the operating means are not connected thereto,

Fig. 5 is a schematic side view of a seat placed in a vehicle with means for detecting the position of the backrest, and

Fig. 6 shows a cross-section through an upper part of a seat with movable head support and means for automatically adjusting the position thereof. A vehicle seat 1 (fig. 1) comprises a seat part 2 and a backrest 3 connected pivotally thereto. Vehicle seat 1 is fixed in conventional manner to the floor 5 of a vehicle for sliding via guide rails 4. Vehicle seat 1 is provided in conventional manner with a locking mechanism for fixing thereof in longitudinal direction relative to floor 5, only a control handle 6 thereof being shown, in addition to a mechanism for adjusting the height of the seat surface, of which only a control knob 7 is shown.

Seat part 2 is formed by a seat part frame 8 and a cushion 9 arranged thereon. Cushion 9 can be manufactured from any suitable material, such as for instance a plastic foam, a granule bed and the like. Backrest 3 is also formed by a frame 10 and a cushion 11 arranged thereon which can likewise be manufactured from any suitable material. In the shown embodiment there is also formed on the upper part of backrest frame 10 an additional frame 12 which bears a head support 13. It is however also conceivable for the head support to be formed in conventional manner as a separate unit which is connected to backrest 3 for adjustment in height direction.

According to the present invention the seat 1 is provided with a device 14 for moving backrest 3 in relation to seat part 2. This moving device 14 is herein embodied such that an angle between seat part 2 and backrest 3, once adjusted, is maintained during a movement of the backrest in that the backrest 3 is moved parallel to itself. In the shown embodiment the moving device 14 is provided for this purpose with three connecting members 15,16,17 which are arranged between seat part 2 and backrest 3 and which together form a gear system. Each toothed wheel 15,17 is herein connected to a bracket 18 respectively 19 which forms part of seat part frame 8 respectively backrest frame 10. In the shown embodiment such a bracket 18,19 is arranged on either side of each frame 8,10, and moving device 14 thus comprises two gear systems which are mutually connected by a shaft 20 extending transversely through backrest 3. The intermediate wheel 16 is mounted on a joining link 21 which is pivotally connected to bracket 18 of seat part frame 8 on one side and to bracket 19 of backrest frame 10 on the other. The moving device 14 is operated by operating means 24. These operating means here take the form of a rotary knob arranged on an outer end of connecting shaft 20. Connecting shaft 20 is otherwise connected non- rotatably to both brackets 19 of backrest frame 10 by means of a press fitting or a splined connection, while shaft 20 is mounted for free rotation in joining links 21 provided with the planetary gears 34 and 35. Shaft 20 thus forms with brackets 19 a mechanism for adjusting the angle of backrest 3 in relation to seat part 2. The moving device is also provided with means for fixing the operating means 24 in both operative positions. These fixation means are formed in the shown embodiment by two grooves 30,31 in shaft 20, the mutual distance between these grooves corresponding with the displacement of shaft 20 between the two operative positions. These grooves co-act with pins 32 which are biased toward shaft 20 by compression springs 33. When shaft 20 is thus moved from the one position to the other, fixation pins 32 are pressed counter to the force of springs 33 out of the relevant groove and the surface of the shaft slides along these pins 32 until the other groove lies in register with the pins. The pins are then pressed into this other groove by the force of springs 33, whereby shaft 20 is once again fixed. In the shown embodiment the operating means 24 can thus be used both to adjust the angle of backrest 3 and to operate the moving device 14. For this purpose the shaft 20 is embodied for sliding in longitudinal direction and provided with coupling rosettes 25 connected non-rotatably thereto which can be placed into engagement with toothed wheels 17 of backrest frame 10. When these coupling rosettes 25 do not engage in toothed wheels 17, shaft 20 can be rotated freely in the planetary gear 35.

Operating means 24 are biased to the position in which the connecting rosettes 25 are disengaged from toothed wheels 17 by biasing means 26, here in the form of a compression spring clamped between a bracket 19 of the backrest frame and cap 27 of shaft 20, and operating means 24 therefore act only to adjust the angle of backrest 3 in relation to seat part 2 (fig. 4) . When in this position the knob 24 of the operating means is rotated, the shaft 20 is rotated while co-displacing brackets 19, and therefore backrest 3. The gear system will herein not be further activated, so that the position of backrest 3 is not therefore changed in height direction.

Conversely, if operating means 24 are moved counter to the force of biasing spring 26 to a position in which the connecting rosettes 25 engage in toothed wheels 17, a rotation of knob 24 then results not only in a rotation of shaft 20, and thus a rotation of brackets 19, but also in a corresponding rotation of toothed wheel 17, whereby the intermediate wheel 16 is set into rotation and toothed wheel 15 will rotate while co-displacing the joining link 21 with the two planetary gears 34 and 35. Backrest 3 is hereby moved upward or downward, wherein a rotation simultaneously takes place around shaft 22 of planetary gear 34 which is aligned to the rotation of backrest 3 around shaft 20, whereby the position of backrest 3 in relation to seat part 2 is thus held constant.

The height of backrest 3 in relation to seat part 2 can thus be readily adjusted without the angle of inclination of backrest 3 therein being changed, whereby people of differing body length can find an optimum seating in seat 1. This optimum seating results in less fatigue and a better protection, particularly in the case of rear-end collisions. This latter advantage makes itself felt particularly in combination with the safety device as described in the stated non-prepublished international application PCT/NL01/00074 of applicant. In the shown embodiment the brackets 18 of seat part frame 2 are further also provided with a bearing opening 28 and a spring-loaded catch 29, whereby the shown mechanism is also suitable for use in a folding seat to facilitate the entry of rear seat passengers into vehicles with only two doors. It is also possible to make use of an automatic adjusting mechanism instead of a manual adjustment. Close to the top side of backrest 3, in the shown embodiment at the height of the upper edge of head support 13, can be arranged means 34 for detecting the position of backrest 3 in height direction (fig. 5).

These detecting means 34 are connected to means 38 for comparing the detected position with a predetermined optimal position. Comparing means 38 are in turn connected in controlling manner to means (not shown here) for displacing backrest 3 to the desired position when comparing means 38 indicate that backrest 3 is not occupying the correct position. These displacing means can be formed by a random drive, for instance an electric motor, which takes the place of the rotary knob 24 as shown in the foregoing figures. In the shown embodiment the detecting means 34 are integrated with comparing means 38. The integrated detecting and comparing means 34, 38 are herein formed by a transmitter/receiver unit 35, for instance a light source with light-sensitive cell, and a reflector 36 placed in the transmission range thereof. This reflector 36 is connected to a fixed point, and is arranged here on windscreen 37 close to the upper edge thereof. When a light beam 39 emitted by transmitter/receiver unit 35 is reflected by reflector 36 and is received again by transmitter/receiver unit 35, this is an indication that the head 40 of the passenger is not situated in the beam 39, and the position of backrest 3 with head support 13 is therefore too high. The detecting and comparing means 34, 38 then transmit a control signal to the drive, whereby backrest 3 is moved downward until the beam 39 is interrupted by the head 40. Depending on the placing of transmitter/receiver unit 35 and the design of backrest 3 and head support 13, backrest 3 can still be moved from that moment through a predetermined distance upward or downward in order to adjust the optimal position.

The beam 39 must also be relatively widely diverging, since the angle at which the beam 39 is emitted can vary considerably owing to the adjustment of the angle of backrest 3 in relation to seat part 2, and reflector 36 must of course be caught inside the beam 39 under all conditions.

The transmitter/receiver unit 35 could of course also be arranged at a fixed point in the vehicle, wherein reflector 36 could then be connected to the backrest 3.

It is also possible to connect head support 13 movably to backrest 3. The height of head support 3 in relation to backrest 3 could hereby be adjusted, but even more important is the adjustment of the correct distance d between the head 40 of the user and the front side of head support 13. Because this distance d is of great importance for the effectiveness of head support 13, the adjustment thereof is preferably not left to the user but performed automatically.

Arranged for this purpose in head support 13 are means 41 for detecting the position thereof, in this case in the form of a distance measuring device 42 directed at the head 40 (fig. 6) . This distance measuring device 42 is connected to means 43 for comparing the measured distance with a predetermined optimal distance, for instance in the order of 4 to 6 cm. These comparing means 43 are in turn connected to means 44 for displacing head support 13.

Displacing means 44 here comprise a motor 46 which is driven by control electronics 45 and which via a transmission 47 drives a worm 48 which in turn engages in a toothed wheel 49. This toothed wheel 49 is connected non-rotatably to a control rod 50, one end of which is pivotally connected to a part of the backrest frame 10 and the other end of which is pivotally connected to frame 12 of head support 13. In combination with a follower rod 51 likewise pivotally connected to these two frames 10, 12, a parallelogram is thus formed. A practically horizontal displacement of head support 13 is ensured by limiting the movement of rods 50, 51 to the upper segment of a circular arc around their connection to the backrest frame 10. So as to prevent continuous reciprocal movement of the head support at any small head movement of the passenger, the detecting means 41, comparing means 43 and/or displacing means 44 can only be switched on periodically. Although the invention is elucidated above with reference to a number of embodiments, it will be apparent that it is not limited thereto. Instead of a gear system, a four-link system in the form of a parallelogram could for instance be used to perform the movement of the backrest in relation to the seat part. Other mechanisms can of course also be envisaged, for instance on the basis of a sliding movement using carriages and guide rails. In addition, it is not of course essential for both the angular adjustment and the height adjustment to have to be operated with one set of operating means. Separate operating means could be provided for these two mechanisms. The movable head support and the associated adjusting mechanism could, while retaining the advantages associated therewith, also be applied in a seat with conventional backrest. The adjusting mechanism can of course also be varied in a variety of ways.

The scope of the invention is therefore defined solely by the appended claims.

Claims

1. Seat, in particular vehicle seat, comprising a seat part and a backrest pivotally connected thereto, characterized in that the backrest is movable in relation to the seat part.

2. Seat as claimed in claim 1, characterized in that the backrest defines a main plane, and is movable substantially parallel to the main plane.

3. Seat as claimed in claim 1 or 2, characterized by means for detecting the position of the backrest, means connected to the detection means for comparing the detected position to a desired position, and means connected controllably to the comparing means for displacing the backrest to the desired position.

4. Seat as claimed in claim 3, characterized in that the detecting means and the comparing means are integrated and formed by at least one transmitter/receiver unit connected to the backrest and at least one reflector arranged at a fixed point in the transmission range of the unit.

5. Seat particularly as claimed in any of the foregoing claims, characterized by a head support connected movably to the backrest, and means for detecting the position of the head support, means connected to the detecting means for comparing the detected position to the desired position, and means connected controllably to the comparing means for displacing the head support to the desired position.

6. Seat as claimed in claim 5, characterized in that the detection means comprise at least one distance measuring device directed at the head of a user.

7. Device for moving relative to each other two elements pivotally connected to each other, such as a seat part and a backrest of a seat.

8. Device as claimed in claim 7, characterized in that it is adapted to maintain a set angle between the elements during a movement thereof.

9. Device as claimed in claim 8, characterized in that one of the elements is fixed and the other element is connected thereto for movement parallel to itself via at least one connecting member.

10. Device as claimed in claim 9, characterized in that the at least one connecting member is rotatable.

11. Device as claimed in claim 10, characterized by three mutually co-acting connecting members which together form a gear system.

12. Device as claimed in claim 11, characterized in that the gear system comprises at least two toothed wheels, each connected to one of the elements, and at least one intermediate wheel placed between the toothed wheels.

13. Device as claimed in claim 12, characterized by four mutually co-acting connecting members which together form a linkage.

14. Device as claimed in claim 13, characterized in that the linkage is a parallelogram.

15. Device as claimed in any of the claims 9- 14, characterized by operating means co-acting with the at least one connecting member.

16. Device as claimed in claim 15, further provided with a mechanism for adjusting the angle between the elements, characterized in that the adjusting mechanism is connected controllably to the operating means.

17. Device as claimed in claim 16, characterized in that the operating means are movable between a position in which they engage the connecting member and a position in which they engage the adjusting mechanism.

18. Device as claimed in claim 17, characterized by means for biasing the operating means to one of the positions.

19. Device as claimed in claim 17 or 18, characterized by means for locking the operating means in at least one of the positions.