WO2001023207A1

WO2001023207A1 - Force transmission for releasing the locking catch of a folding backrest of a motor vehicle seat

Info

Publication number: WO2001023207A1
Application number: PCT/EP2000/008417
Authority: WO
Inventors: Manuel Fernando Braga Ferreira Da Silva; Rui Antonio Cruz Fernandes De Pinho
Original assignee: Fico Cables, Lda
Priority date: 1999-09-30
Filing date: 2000-08-29
Publication date: 2001-04-05
Also published as: DE19947002A1; DE19947002B4

Abstract

The invention relates to a security mechanism for locking a folding seat, in particular for a motor vehicle, with at least one locking unit (20) which is unlocked by a pulling movement, a control unit (10) for providing a pushing movement and a bowden cable (40) for unlocking the locking unit (20) with the control unit (10), wherein the pushing movement provided by the control unit (10) is transmitted onto a sheath (41) of the bowden cable (40) to transform it into a pulling movement for unlocking the at least one locking unit (20).

Description

FORCE TRANSMISSION FOR RELEASING THE LOCK ING CATCH OF A FOLDING BACKREST OF A MOTOR VEHICLE SEAT DHUNK" UI- A

1. Technical field:

The present invention relates to a security mechanism for locking a seat, in particular for a motor vehicle.

10

2. The prior art:

Motor vehicles are often provided with seats which can be folded, if necessary. Folding seats serve in particular in the case of cars to enlarge the trunk of the vehicle. However, also in camping cars or vans folding seats allow a flexible use of 15 the available space of the passenger compartment.

The backrest must be locked so that the folding seat(s) remains in the upright position. To this end, devices are provided which fix the backrest to the frame of the vehicle. Either, a locking unit is mounted in the upper region of the seat interact- 20 ing with corresponding latching elements in the frame of the vehicle or the arrangement is inverted, i.e. the locking element is provided at the frame of the vehicle and secures by engaging a latching element in the upper part of the seat the upright position of the backrest.

25 In order to reliably avoid in case of an accident an unintended forward folding of the backrest, it is reasonable - and in many countries prescribed - that the position of the backrest is additionally to the already mentioned locking unit in the upper part of the seat further secured by another independent locking unit which is typically arranged in the lower part of the seat. This further locking unit consists for

30 example of a massive spring-biased metal bolt which engages in dependence on its mounting position a corresponding opening/recess of the seat or the frame of the vehicle. For the release of this additional safety device the bolt has to be pulled against the force of the spring out of the opening/recess.

If the backrest is to be forwardly folded, the two mentioned locking units are to be preferably simultaneously unlatched in order to release the backrest. For ergo- nomic reasons this is typically done by a pushing movement, i.e. the pressing of an operating knob. In security mechanisms according to the prior art this pushing movement is in the upper locking unit directly used for the release of the backrest. However, since the lower locking unit can according to the safety regulations only be released by applying a pulling force (see above) a complex lever mechanism is provided in locking devices according to the prior art transforming the pushing movement of the operating knob into a pulling movement for the release of the bolt.

The mentioned lever mechanism comprises a plurality of movable parts and increases thereby on the one hand the costs for the production of the vehicle and is on the other hand likely to fail. Further, the overall weight of the vehicle is increased by the lever mechanism which negatively effects the fuel consumption.

It is therefore the problem of the present invention to provide a simple and reliable security mechanism for locking a folding seat which transforms without a lever mechanism a pushing movement into a pulling movement for unlatching a locking unit.

3. Summary of the invention

The invention relates to a security mechanism for locking a folding seat, in particular for a motor vehicle with at least one locking unit unlocked by a pulling movement, a control unit for providing a pushing movement and a bowden cable for unlatching the locking unit by the control unit, wherein the pushing movement provided by the control unit is transmitted onto the sheath of the bowden cable to transform it into a pulling movement for the release of the at least one locking unit.

In other words, the pushing movement in the control unit is according to the in- vention not transmitted to the inner cable of the bowden cable but onto the outer sheath. Thus, a relative movement of the end of the inner cable into the sheath of the bowden cable is caused at the other end of the bowden cable which can be used as a pulling movement for unlatching the locking unit. A separate transformation of the pushing movement by a lever mechanism or the like is therefore not necessary according to the invention.

Preferably, the pushing movement is additionally transmitted onto a second locking element. This transmission is preferably achieved by a shaft. As a result, a simultaneous unlatching of two locking units is achieved allowing a simple re- lease for folding the backrest of the seat.

In a preferred embodiment the control unit comprises an outer frame wherein an operating element for the pushing movement is movably suspended. The outer frame of the control unit comprises preferably a support for one end of the inner cable of the bowden cable. The sheath of the bowden cable is in the preferred embodiment attached to the operating element so that under a pushing movement of the operating element the sheath of the bowden cable is moved away from the end of the inner cable of the bowden cable whereby a relative movement of the end of the inner cable with respect to the outer sheath is caused at the other end of the bowden cable.

Preferably, the operating element comprises two struts having a mounting plate of the frame arranged therebetween which takes up the support. Preferably, a readjusting spring for the operating element is additionally arranged on the mounting plate. The sheath of the bowden cable is preferably attached to the lower end of one of the two struts. Further preferred developments are the subject matter of further dependent claims.

4. Short description of the drawing In the following detailed description a presently preferred embodiment of the present invention is described with reference to the drawing, which shows:

Fig. 1 : A perspective general view of the security mechanism;

Fig.2: A perspective view of a section through the control unit and the second locking unit;

Fig. 3: A perspective view of a section through the first locking unit.

5. Detailed description of the invention

With reference to Fig. 1 a preferred embodiment of the present invention comprises a control unit 10 for the simultaneous unlocking of a first 20 and a second locking unit 30. The control unit 10 as well as the two locking units 20, 30 can either be inserted into the folding seat (not shown) and interact with a corresponding latching element (not shown) or an opening/recess (not shown) in the frame of the vehicle or the complete security mechanism is arranged inside the frame of the vehicle and the corresponding elements are arranged in the seat.

For the preferred simultaneous unlatching of the two locking units 20, 30, an operating element 11 is provided in the control unit 10, the movements of which are transmitted onto the first locking unit 20 via a bowden cable 40 and onto the second locking unit 30 via a shaft 50. The arrangement of the control unit 10 and the two locking units 20, 30 in the seat or the frame of the vehicle determines the length and shape of the shaft 50 as well as the length of the bowden cable 40. In the upper part of Fig. 2 the inner construction of the control unit 10 is shown in detail. The operating element 11 is preferably slidably arranged in the frame 12. The frame 12 encompassing the operating element 11 serves preferably also for the attachment to the seat or the frame of the vehicle. By means of two lateral struts 13 the upper part of the operating element 1 1 is connected to a lower part comprising a recess 15 for the upper head 51 of the shaft 50 as well as a mounting 14 for the sheath 41 of the bowden cable 40. The mounting 14 is preferably provided at the lower end of one of the two struts 13. The inner cable 42 of the bowden cable extends preferably through the mounting 14 to a receptacle 16 for the ball shaped thickening 43 at the end of the inner cable 42 of the bowden cable 40. According to the invention the receptacle 16 is preferably rigidly connected to the frame 12 and not to the slidably suspended operating element 11. To this end a mounting plate 18 is preferably arranged between the two struts 13 which is integrally connected with the front side (not shown) and the backside of the frame 12.

When the operating element 11 is downwardly pushed, the recess 15 as well as the mounting 14 of the sheath 41 move into a downward direction (cf. the upper vertical arrows in Fig. 2). Thus, on the one hand the shaft 50 is downwardly moved on the other hand the relative distance between the upper end of the sheath 41 and the fixed thickening 43 at the upper end of the cable 42 is increased. This leads at the other end of the bowden cable to a movement of the lower end of the inner cable 42 into the surrounding sheath 41. As a result, the downwardly directed pushing of the operating element 11 is simultaneously transformed into a pushing movement of the shaft 50 and a pulling movement of the bowden cable 40. When the pressure onto the operating element 11 is released, it is preferably brought back into its starting position by a readjusting spring 17 which is preferably arranged between said mounting plate 18 and the upper part of the operating element.

Fig. 3 shows a detailed view of the first locking unit 20. Inside a tube-like bushing 21 a security bolt 22 is preferably slidably arranged. For attachment to the seat or the frame of the vehicle the bushing 21 comprises several latching projections. By means of the spring 24, the security bolt 22 is pushed into its extended, i.e. locking position, where it engages a corresponding opening/recess (not shown) in the seat or the frame of the vehicle. At the inner end of the security bolt 22 the lower end of the inner cable 42 of the bowden cable 40 is attached in a slit support 25. The outer sheath 41 is rigidly connected with the other end 26 of the bushing 21.

As explained above, a pressure onto the operating element 11 of the control element 10 leads to a movement of the lower end of the inner cable 42 in the direction of the sheath 41. Since the sheath 41 is rigidly connected to the bushing 21, the security bolt is thus pulled against the force of the spring 24 and the locking unit 20 is thereby unlatched. If the tension of the inner cable 41 decreases, the compressed spring 24 pushes the bolt against into its starting position (cf. double headed arrow in Fig. 3).

In the lower part of Fig. 2, the construction of the second preferred locking element 30 is shown in detail. The lower end of the shaft 50 also comprises a head 52 engaging a corresponding receptacle 31. The receptacle 31 is arranged on a slide 54 which is preferably slidably suspended inside a housing 53. The vertical pushing movement of the shaft 50 therefore pushes the slide 54 downwardly (cf. the lower vertical arrow in Fig. 2). Thus, a latching element (not shown) inserted from the side along the dashed arrow in Fig. 2 is released and thus the second locking element 30 unlocked. When the pressure onto the operating element 11 and thereby the pressure onto the shaft 50 terminates, a further readjusting spring 55 pushes the slide 54 back into its original position.

The slide 54 comprises in the part which is directed to the latching element to be inserted (not shown) a skewed area 56. Thus, an automatic locking of the two locking units 20, 30 is possible: By means of the skewed area 56 the slide 54 is downwardly pushed when the corresponding latching element is inserted. Since the locking element 11 is by means of the shaft 50 simultaneously downwardly pulled (i.e. it performs the same movement as under a manual pressure onto the operating element 1 1 from above) and the bowden cable 40 is thus operated, the security bolt 22 of the first locking element 20 is simultaneously pulled back (see above). When the slide 54 snaps back, for example into a recess of the latching element, also the security bolt 22 is by this direct coupling simultaneously ex- tended into the corresponding opening/recess (not shown) so that the two locking units 20, 30 are simultaneously locked.

Although the control unit 10 is in the described preferred embodiment separated from the second locking unit 30, it is also conceivable to integrate the two units into each other, for example when the operating element 11 performs simultaneously the function of the slide 54. Thus, further reductions of the weight and the volume are possible.

For costs reasons stable plastics, in particular polyamide are preferred suitable materials for the described components. The security bolt 22 which is in case of an accident subjected to considerable load is, however, as well as the inner cable 41 of the bowden cable 42 preferably made of metal.

Claims

1. Security mechanism for locking a folding seat, in particular for a motor vehicle, comprising:

a) at least one locking unit (20), unlocked by a pulling movement;

b) a control unit (10) for providing a pushing movement;

c) a bowden cable (40) for unlocking the at least one locking unit (20) by the control unit (10), wherein

d) the pushing movement provided by the control unit (10) is transmitted on the sheath (41) of the bowden cable (40) to transform it into a pulling movement.

2. Security mechanism according to claim 1 , wherein the at least one locking unit (20) comprises a moveably suspended bolt (22) engaging for locking a corresponding opening or recess.

3. Security mechanism according to claim 2, wherein the moveably suspended bolt (22) is pressed by a spring element (24) into the opening or recess and wherein it can be pulled from the opening or recess by an inner cable (42) of the bowden cable (40).

4. Security mechanism according to the claims 1 to 3, wherein the pushing movement is additionally transmitted onto a second locking element (30).

5. Security mechanism according to claim 4, wherein the pushing movement is transmitted onto the second locking element (30) via a shaft (50).

6. Security mechanism according to claim 4, wherein the second locking element (30) is integrated into the control unit (10).

7. Security mechanism according to one of the preceding claims, wherein the locking unit (10) comprises an outer frame (12) in which the operating element (11) for the pushing movement is slidably arranged.

8. Security mechanism according to claim 7, wherein the frame (12) comprises a support (16) for one end (43) of the inner cable (42) of the bowden cable (40) and wherein the sheath (41) of the bowden cable is directly or indirectly attached to the operating element (11).

9. Security mechanism according to claim 8, wherein the operating element (11) comprises two struts (13) having a mounting plate (18) of the frame (12) arranged therebetween which receives the support (16).

10. Security mechanism according to claim 9, wherein additionally a readjusting spring (17) for the operating element (11) is arranged on the mounting plate (18).

11. Security mechanism according to one of the claims 9 or 10, wherein the sheath (41) of the bowden cable (40) is fixed to the lower end (19) of one of the two struts (13).

12. Folding seat, in particular for a motor vehicle having a security mechanism according to one of the claims 1 to 11.