GB2309892A

GB2309892A - Latch fitting for vehicle seats

Info

Publication number: GB2309892A
Application number: GB9700345A
Authority: GB
Inventors: Wolfgang Boltze; Richard Hansel; Werner Wittig
Original assignee: Keiper Recaro GmbH and Co
Current assignee: Keiper Recaro GmbH and Co
Priority date: 1996-02-09
Filing date: 1997-01-09
Publication date: 1997-08-13
Anticipated expiration: 2017-01-09
Also published as: JP3208080B2; GB2309892B; FR2744960B1; JPH09217712A; DE19604672C1; FR2744960A1; GB9700345D0

Description

2309892 1 Latch fitting for vehicle seats.

The invention relates to a latch fitting for vehicle seats, which has the features of the preamble of claim 1.

With the known latch fittings of that kind, the pivoting range of the seat back in a backward direction is limited by a mechanical stop member for the upper part of the fitting joined to the seat back. In order to be able to ensure that even in this rearmost pivoted position the latching device locks as soon as the actuating element of the latching device is released, small manufacturing tolerances have to be adhered to, which is expensive. This applies particularly when the latching device is constructed so that as the seat back is loaded in a backward direction the force transferred by way of the teeth of the latching device to the toothed pawl creates a moment that presses the teeth of the toothed pawl more forcefully into the teeth of the toothed segment. When the latching device is constructed in this manner, the toothed pawl can in fact be 2 pivoted into its blocked position only when the toothed segment simultaneously performs a rotary movement.

The invention is based on the problem of providing a latch fitting of the kind mentioned in the introduction with which it is possible, even in when the fitting is in one end position, costeffectively to ensure that when the actuating element for the toothed pawl is released the latter will come into engagement with the toothed segment and thus lock the fitting. This problem is solved by a latch fitting having the features of claim 1.

In the case of the latch fitting according to the invention, the mechanical stop member limiting the pivoting range in the one direction is omitted, thereby also eliminating the need for close tolerances to be adhered to. To be precise, as the fitting part lockable by means of the toothed pawl p ivots towards a predetermined end position, the control device associated with the toothed pawl causes the pivoting movement of the toothed pawl to be matched to the pivoting movement of the toothed segment, so that the tooth or the teeth of the toothed pawl are aligned with the spaces between the teeth of the toothed segment before 3 the toothed pawl starts to engage with the teeth of the toothed segment, and in the predetermined end position the toothed pawl engages without play with the teeth of the toothed segment. This linking of the pivoting movement of the toothed pawl with the pivoting movement of the toothed segment does not prevent the latching device from being closed by means of the actuating element in the pivoted positions lying within the pivoting range. In addition, in those pivoted positions there is no interference when the tooth or the teeth of the toothed pawl initially do not align with the spaces between the teeth of the toothed segment, because in those pivoted positions the seat back can be moved far enough forwards or backwards for the toothed pawl to lock into the toothed segment. Alternatively, however, the control device can be constructed so that it is effective only in an end portion of the pivoting range which is limited by the predetermined end position.

In a preferred construction, the control device comprises a mechanical gear mechanism which, starting at a defined pivoted position of the fitting part having the toothed segment, transmits the movement of that fitting part to the toothed pawl according to a given relation. Such a 4 control device can be realized simply and in a space-saving manner. This applies particularly when the mechanical gear mechanism has a control cam providing the given relation and a follower element following that cam.

In an embodiment that is especially advantageous because of its simplicity, a drag lever is rotatably mounted on the axis of articulation and, as the fitting part having the toothed segment moves towards the predetermined pivoted position, is constrained to pivot with it. The gear connection of this drag lever with the toothed pawl follows in that case by way of the control cam and the follower element. The control cam preferably defines a window in the drag lever. Driving of the drag lever is rendered possible, for example, by means of a pin.

If the window is in the shape of a slot following the control cam, a pivoting movement of the toothed pawl by means of the actuating element effects a pivoting movement of the drag lever. The window can alternatively be configured so that a pivoting movement of the toothed pawl by the actuating element can be effected without a simultaneous pivoting movement of the drag lever.

Instead of just a single predetermined pivoted position, which limits the pivoting range in the one pivoting direction, at least two selectable predetermined pivoted positions can be provided. If the control device has a drag lever, all that is required is to select corresponding different positions for the driver member. Such a driver member can be in the form, for example, of a rotatable eccentric disc that can be set into different rotated positions. When using a pin as the driver member, however, it is also possible in a simple manner to provide different predetermined pivoted positions. For that purpose, the pin merely requires to be inserted into different positions, or, for example, to be movable by means of a slider member.

Through linking the pivoting movements of the toothed segment and the toothed pawl, it is possible without difficulty to cater for the position of the tooth or the teeth of the toothed pawl in relation to its axis of articulation so that a loading of the fitting part having the toothed segment towards the predetermined pivoted position onto the toothed pawl engaging in the toothed segment produces a torque such that the application force of the toothed pawl against the teeth of the toothed segment is increased.

6 The invention is explained in detail hereinafter with reference to embodiments illustrated in the drawings, in which Figure 1 is a view of a first embodiment with the latching device released and with the upper fitting part in a pivoted position close to the rear end of the pivoting range; Figure 2 is a view of the first embodiment at the start of the constrained movement of the toothed pawl into the interlocked position as the upper fitting part approaches the rear end of its pivoting range; Figure 3 is a view of the first embodiment in which the upper fitting part has approached even closer to the rear limitation of its pivoting range; Figure 4 is a view of the first embodiment with the upper fitting part in a pivoted position corresponding to the rear end of the pivoting range; Figure 5 is a view of a second embodiment in 7 which the latching device is open and the upper fitting part is in a pivoted position close to the rear end of the pivoting range; and Figure 6 is a view of a third embodiment in which the latching device is open and the upper fitting part is in a pivoted position close to the rearward end of the pivoting range.

A latch fitting for vehicle seats, by means of which a seat back is pivotable about an axis of articulation 2 and is arranged to be connected in selectable pivoted positions immovably with the supporting structure of the seat mart by means of a latching device, comprises a lower fitting part 1 to be joined to the supporting structure of the seat part and, pivotally connected thereto by way of the axis of articulation 2, a panellike upper fitting part 3, which is to be joined to the seat back- The material part of the upper fitting part 3 projecting downwards beyond the axis of articulation 2 forms a toothed segment 4, of which the downwardly directed teeth 41 concentric with the pivot pin 2 extend in the embodiment only over a middle portion of the lower edge of the upper fitting part 3. Beneath the toothed segment 4 a 8 toothed pawl 6 is articulated to the lower fitting part 1 by means of a pin 5, which lies parallel to the axis of articulation 2; the toothed pawl 6 lies in the same plane as the toothed segment 4. Along its longitudinal side facing the toothed segment, the toothed pawl 6 is provided with teeth 61 matched to the teeth 41.

The arrangement of the teeth 61 with respect to the pin 5 is selected so that, when the latching device is closed, the force transmitted by way of the teeth 4' and 61 to the toothed pawl 6 as a result of loading of the upper fitting part 3 to perform a pivoting movement in a clockwise direction, when viewed as in Figure 1, leads to a torque which presses the teeth 6' more forcefully into the teeth 4', that is, a torque which acts anti-clockwise when viewed as in Figure 1.

From the disengaged position of the toothed pawl 6 illustrated in Figure 1, in which its teeth 61 are not engaged with the teeth 41, so that the upper part 3 of the fitting 3 can be pivoted relative to the lower part 1 of the fitting, the toothed pawl 6 can be pivoted anti-clockwise, when viewed as in Figure 1, into its blocked position, in which the teeth 61 engage without play in the teeth 41; as a result, the upper part 3 of the fitting is 9 interlocked positively and without play with the lower part 1 of the fitting. For this pivoting movement of the toothed pawl 6, beneath the same an actuating element 8 is articulated by means of a pin 7 to the lower fitting part 1; the actuating element 8 lies in the same plane as the toothed pawl 6. The actuating element 8 is provided at its free end with an interception cam 9 and adjoining that a clamping cam 10. The actuating element 8 can be held'in the pivoted position illustrated in Figure 1 against the force of a pre-tensioned spring, in which position the toothed pawl 6 is located in its disengaged position. If the actuating element 8 is released it is pivoted by the pre-tensioned spring in the clockwise direction, when viewed as in Figure 1. Since the actuating element 8 bears against the lower longitudinal side of the toothed pawl 6, this pivoting movement causes the toothed pawl 6 to pivot into its blocked position. For this, first of all the interception cam 9 and then the clamping cam 10 comes to bear against the lower longitudinal edge of the pawl 6. The slope of the clamping cam 10 is chosen so that self-locking does not occur. On the other hand, self-locking is achieved when the interception cam 9 is effective. By this means, when the upper fitting part 3 is overloaded, no jamming takes place, on the contrary, the toothed pawl 6 is pivoted so far in a clockwise direction, when viewed as in Figure 1, that the interception cam 9 becomes effective and prevents a further pivoting movement of the pawl 6. The teeth 61 of the pawl 6 are here still largely in engagement with the teeth 4' of the toothed segment 4.

In order positively, that is, independently of the actuating element 8, to lock the upper fitting part 3 in the end position as the upper fitting part is pivoted clockwise, when viewed as in Figure 1, into that end position, a control means is associated with the toothed pawl 6, this control means consisting, in this embodiment, of a mechanical gear mechanism. This gear mechanism has a drag lever 11 which is pivotally mounted on the axis of articulation 2, extends downwards away from the axis of articulation 2, and engages with its lower end portion over part of the toothed pawl 6. In this lower end portion there is provided a window in the form of a control slot 12 in which a pin 13 projecting from the toothed pawl 6 and arranged parallel with the pin 5 engages. The pin 13 acts as a follower pin for the control cam 121 forming the lower edge of the control slot 12. Furthermore, the control device comprises a driver pin 14 projecting from the upper fitting part 3; in an end portion of the pivoting range of the upper fitting part 3 the driver pin is engaged with the drag lever 11 and forcibly moves the pivoted lever 11 with it as the upper fitting part 3 is pivoted into the end position, that is, when viewed as in Figure 1, on a pivoting movement clockwise.

The control cam 121 is constructed so that during this constrained pivoting movement of the drag lever 11, which is effected from a defined pivoted position of the upper fitting part 3, the toothed pawl 6 is constrained to pivot from its disengaged position, in which the pin 13 lies virtually at one end of the control slot 12, into the interlocked position in a movement matched to the pivoting movement of the toothed segment 4, as shown in Figures 2 to 4. These Figures also show that the teeth of the toothed pawl 6 are directed towards the particular spaces between the teeth 41 of the toothed segment 4 which they must enter in order to lock the upper fitting part 3 in its end position. If, once this end position has been reached, the actuating element 8 is released, then it pivots clockwise, when viewed as in Figure 4, into its effective position, in which its clamping cam 10 bears against the underside of the toothed pawl 6 and holds the teeth thereof in engagement 12 without play with the teeth 41 of the toothed segment 4. When the toothed pawl 4 locks the upper fitting part 3 in its rear end position, the pin 13 is located close to the rear end of the control slot 12, as illustrated by Figure 4.

If the upper fitting part 3 is to be pivoted out of its end position, anti-clockwise when viewed as in Figure 4, the actuating element 8 needs only to be pivoted into the inactive position illustrated in Figure 4. The toothed pawl 6 can then be pivoted into its disengaged position by exerting on the upper fitting part 3 a force in the sense of a forward pivoting movement, which applies also for a change in the angular position from a different pivoted position. The force transmitted to the toothed pawl 6 by way of the teeth 41 and 61 then exerts a torque clockwise when viewed as in Figure 4, which disengages the toothed pawl 6 from the teeth 4' of the toothed segment 4 and in addition, by way of the pin 13 and the control cam 121, also pivots the drag lever 11. If the actuating element 8 is released in the new pivoted position, it pivots the toothed pawl 6 into its blocked position. In addition, the drag lever 11 is pivoted clockwise.

13 The second embodiment illustrated in Figure 5 differs from the abovedescribed first embodiment merely in the different form of the window 112 defined by the control cam 121 in the drag lever 111. Parts that correspond are therefore denoted by reference numbers increased by one hundred. In respect of corresponding features the reader is referred to the remarks pertaining to the first embodiment.

The control cam 112' has the same shape and position in the drag lever 111 as the control cam 121 in the drag lever 11. Adjoining each end of the cam there are, however, two edge portions of the window 112, of which one extends approximately parallel to the lateral edge of the drag lever 111 and the other extends approximately at a right angle thereto. The window 112 is therefore in the form of a segment, the dimensions of which are chosen so that when the toothed pawl 106 is pivoted by means of the moving member 108 into the blocked position, the pin 113 of the toothed pawl 106 is able to move freely in the window 112, that is, need not move the drag lever 111.

The third embodiment illustrated in Figure 6 differs from the first embodiment merely in that there is a choice of several pivoted positions of 14 the upper fitting part, in which an enforced interlocking is effected. Parts that correspond are therefore denoted by reference numbers increased by two hundred with respect to the first embodiment. Furthermore, only the differences are explained below. The reader is referred to the remarks concerning the first embodiment for the remaining details.

As Figure 6 shows, the driver pin 214 can be arranged on the upper fitting part 203 in different positions relative to the axis of articulation 202. For example, two or more bores can be provided, in which the driver pin 214 can be inserted as desired. A slider member, for example, is also an option, by means of which the driver pin 214 can be displaced into the different selectable positions.

The longitudinal side of the drag lever 211 provided for engagement with the driver pin 214 has a-stepped configuration. The individual portions 215, 216 and 217 of the surface for engaging with the driver pin 214 provide different angular positions of the drag lever 211 relative to the upper fitting part 203, for which reason the latter in different angular positions reaches the position which corresponds to the one end of the pivoting range and beyond which a pivoting movement clockwise when viewed as in Figure 6 is not possible.

16

Claims

CLAIMS:

1. Latch fitting for vehicle seats, the seat back of which is pivotable by means of the latch fitting about the axis of articulation thereof and is arranged to be connected in selectable pivoted positions immovably with the supporting structure of the seat part by means of a latching device, wherein the latching device comprises a toothed segment provided on one part of the fitting and having teeth concentric with the axis of articulation, and a toothed pawl articulated to the other part of the fitting, which toothed pawl is pivotable by means of an actuating element into an interlocked position, characterised in that the toothed pawl (6; 106) has associated with it a control means (11, 12, 13, 14) which, on a pivoting movement of the fitting part (3; 203) having the toothed segment (4) relative to the other fitting part (1) towards a predetermined pivoted position forcibly moves the toothed pawl (6; 106) towards its interlocked position such that every available tooth of the toothed pawl (6; 106) is aligned with a space between the teeth (41) of the toothed segment (4), when just before reaching the predetermined pivoted position of the fitting part (3; 203) to be locked the toothed 17 pawl (61 106) has to engage with the teeth (4') of the toothed segment (4).

2. Latch fitting according to claim 1, characterised in that the control device (11, 12, 13, 14) comprises a mechanical gear mechanism which, starting at a defined pivoted position o the fitting part (3; 203) having the toothed segment (4), transmitsthe movement of that fitting part (3; 203) to the toothed pawl (6; 106) corresponding to a given relation.

3. Latch fitting according to claim 2, characterised in that the mechanical gear mechanism has a control cam (12'; 1121) realizing the given relation and a follower element (13; 113) following the control cam.

4. Latch fitting according to claim 3, characterised by a drag lever (11; 111; 211) as part of the mechanical gear mechanism, which drag lever is rotatably mounted on the axis of articulation (2) and is forcibly movable by the fitting part (3; 203) having the toothed segment (4) in the pivoting direction of the fitting part towards the predetermined pivoted position, and by a connection of that drag lever (11; 111; 211) 18 with the toothed pawl (6; 106) by way of the control cam (121, 112') and the follower element (13; 113).

5. Latch fitting according to claim 4, characterised in that, in a portion overlapping the toothed pawl (6; 106), the drag lever (11; 111; 211) has a window (12; 112) which is defined by the control cam (121; 1121), and a pin (13) engaging in the window (12; 112) is provided on the toothed pawl (6; 106).

6. Latch fitting according to claim 5, characterised in that the window (12) is in the shape of a slot following the control cam (121).

7. Latch fitting according to claim 5, characterised in that the window (112) has a shape allowing a pivoting movement of the toothed pawl (106) by the actuating element (108) independently of a pivoting movement of the drag lever (111).

8. Latch fitting according to any one of claims 1 to 7, characterised by at least two selectable specific pivoted positions.

9. Latch fitting according to claim 8, characterised in that each of the predetermined 19 pivoted positions is determined by a selectable position of a driver element (214) for the drag lever (211).

10. Latch fitting according to claim 9, characterised in that the driver element is in the form of a rotatable eccentric disc.

11. Latch fitting according to claim 9, characterised in that the driver element is in the form of a pin (14).

12. Latch fitting according to claim 11, characterised in that the bearing surface of drag lever (211) is of stepped form with one section (215, 216, 217) for each predetermined position of the driver element (214).

13. Latch fitting according to any one of claims 1 to 12, characterised in that the position of the pivot axle (2) of the toothed pawl (6) relative to the teeth (61) thereof is selected so that a loading of the fitting part (3) having the toothed segment (4) towards the predetermined pivoted position onto the toothed pawl (6) engaging in the toothed segment (4) produces a torque such that the application force of the toothed pawl (6) against the teeth (41) of the toothed segment (4) is increased.