WO2017009336A1

WO2017009336A1 - Lock for a vehicle seat back

Info

Publication number: WO2017009336A1
Application number: PCT/EP2016/066538
Authority: WO
Inventors: Robert J. Hunt
Original assignee: Kiekert Ag
Priority date: 2015-07-14
Filing date: 2016-07-12
Publication date: 2017-01-19

Abstract

The invention refers to a lock for a motor vehicle seat back comprising a locking mechanism with a rotatably mounted rotary catch (1) for receiving a locking bolt, a pawl (2) with which the rotary catch can be engaged for retaining the locking bolt, a blocking lever (3) capable of blocking the pawl if the latter is located in its engaging position, a release lever (4) for disengaging the locking mechanism, wherein in a locked state, the rotary catch transfers an opening moment onto the pawl and wherein the blocking lever and the release lever are interconnected by a spring which pushes the blocking lever into its blocking position and the release lever into its resting position. Since there is a blocking lever which blocks the pawl in the locked state, a high striker load is possible. Since the rotary catch transfers a pivoting moment onto the pawl in the locked state, it is possible to open the lock with little effort. Since there is only one spring which pushes two components into appropriate positions, the number of parts is reduced.

Description

LOCK FOR A VEHICLE SEAT BACK

FIELD OF THE INVENTION

The invention relates to a lock for a vehicle seat back.

DESCRIPTION OF THE RELATED STATE OF TH E ART

A vehicle seat back often separates a vehicle compartment f rom a luggage compartment being configured so as to be capable of being changed from an upright position to a folded-down position, in which the seat back is folded down to the vehicle front side, and vice versa. A lock locks the seat back in the upright position.

A lock for a vehicle comprises a locking mechanism with a rotatably mounted rotary catch for receiving a locking bolt also referred to as a striker. The locking mechanism moreover comprises a pawl with which the rotary catch can be engaged for retain ing the locking bolt.

The rotary catch of a motor vehicle lock usually comprises a fork-shaped inlet slot (also referred to as inlet opening) which is formed by the load arm and the catching arm and which the striker for example of a door or hatch, e.g. a hood or a trunk lid, enters when the door or hatch is closed. The striker then turns the rotary catch f rom an opened position in the direction of the closed position until the pawl engages the rotary catch . This position is referred to as the catching position . The striker then cannot leave the inlet slot of the rotary catch. In the case of a seat back, an adjacent f rame may comprise the striker and the seat back the lock or vice versa.

Furthermore , a lock can comprise a blocking lever capable of blocking the pawl in its catching position for allowing a high striker load. The blocking lever has to be pivoted or turned out of its blocking position in order disengage the locking mechanism . The paw! is able to leave its catching position for opening the locking mechanism, if the blocking lever has been removed from its blocking position .

There are locks as known from US 2010 052 336 A1 in which the rotary catch is capable of introducing an opening moment into the pawl if the latter is in its catching position. Opening moment means that the pawl may leave its locking position due to the opening moment. Such a lock requires a blocking lever in order to be able to engage the locking mechanism. Such locks can be opened with little effort.

Document US 8,480,138 B2 discloses a lock unit comprising a catch, a pawl having a pawl rotation axis, and a blocking lever, wherein in a locked state, the catch of the lock unit transfers a pivoting moment onto the pawl and wherein the pawl is fixed by means of a blocking lever. Lock units of this type are used in particular in motor vehicles for the purpose of locking doors, tailgates, or similar.

There are motor vehicle locks with two catching positions , i.e. a preliminary catching position and a main catching position . The preliminary catching position serves for rotary catching the respective door or hatch when the latter does not reach the main catching position during the closing process. If, starting from the preliminary catching position, the rotary catch is turned further correspondingly, it will finally reach the main catching position.

As a matter of principle, a lock comprises a release lever which is actuated in order to open or disengage a locking mechanism. Such a release lever is typically connected to a handle. If the handle is actuated, the release lever is actuated and moves from its resting position into its released position in order to disengage the locking mechanism and thus open the lock.

In particular, a lock for a seat back often has a manually actuatable locking and unlocking mechanism comprising a handle. To increase the comfort, such rear seat installations are being provided increasingly more often with an electrical drive in order to unlock respectively to release a locking device of a vehicle seat back.

It is of interest to reduce the release effort for example in order to save electrical energy In the case of an electrical drive and/or to achieve an electric release with small electrically driven actuators. It is also of interest to reduce the number of parts of a lock,

SUMMARY OF THE INVENTION

It is an object of the invention to provide a lock for a motor vehicle seat back comprising a locking mechanism which allows a high striker load.

It is a further object of the invention to provide a locking device for a motor vehicle seat back comprising a locking mechanism which allows a small release effort.

Another object of the invention is to provide a locking device for a motor vehicle seat back having a reduced number of parts.

Another object of the invention is to provide a seat back locking device that retains the seat back from rattling.

Another object of the invention is to provide a seat back locking device that retains the seat back from chucking.

Another object of the invention is to provide a locking device for a motor vehicle seat back having a reduced package size and a reduced overall mass.

In order to solve these objects of the invention, a lock for a motor vehicle seat back comprises a locking mechanism with a rotatably mounted rotary catch for receiving a locking bolt, a pawl with which the rotary catch can be engaged for retaining the locking bolt, a blocking lever capable of blocking the pawl if the latter is located in its engaging position, a release lever for disengaging the locking mechanism, wherein in a locked state, the rotary catch transfers an opening moment onto the pawl and wherein the blocking lever and the release lever are interconnected by a spring which pushes the blocking lever into its blocking position and the release lever into its resting position.

Since there is a blocking lever which blocks the pawl in the locked state, a high striker load is possible. Since the rotary catch transfers a pivoting moment onto the pawl in the locked state, it is possible to open the lock with little effort. Since there is only one spring which pushes two components into appropriate positions, the number of parts is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a lock in its main locking position in accordance with a first exemplary embodiment of the invention;

FIG.2 is a detailed view of the locking mechanism in Its locking position in accordance with the first exemplary embodiment of the invention;

FIG.3 is a view of a lock in its main locking position in accordance with a second exemplary embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1, a lock according to a first embodiment of the present invention comprises a rotary catch 1 , a pawl 2, a blocking lever 3 and a release lever 4. Rotary catch 1 , pawl 2, blocking lever 4 and release lever 5 are rotatably mounted on a metal plate 5 of a case. Rotary catch 1 , pawl 2 and blocking lever 3 are situated in same plane adjacent to the metal plate 5. The release lever 4 is situated above the pawl 2.

The rotary catch 1 comprises a fork-shaped inlet slot 6 which is formed by a load arm 7 and a catching arm 8 and which a striker (not shown) enters when the corresponding seat back is in its upright position. The striker then turns the rotary catch 1 from an opened position in the direction of the closed position until the pawl 2 engages the rotary catch 1 in its catching position as shown in

Fig. 1 .

In the catching position respectively locking position shown in Fig. 1 , the rotary catch 1 introduces an opening moment into the pawl 2. Since the pawl 2 is blocked by the blocking lever 3, the pawl 2 rests in its catching position . Thus, the blocking lever 3 has to be pivoted out of its blocking position in order disengage the locking mechanism.

The blocking lever 3 and the release lever 4 are interconnected by a biased spring 9. One leg 10 of the biased spring 9 rests against a lug 1 1 at the end of one arm of the blocking lever 3 in a pre-stressed manner. The other leg 12 of the spring 9 rests against a hook-shaped pin 13 of the release lever 4 in a pre- stressed manner. The spring 9 is situated between the blocking lever 3 and the release lever 4 and surrounds the axis 14 of the pawl 2 and the release lever 4. Therefore, the axis 14 holds the spring 9 in its position . The spring 9 pushes the release lever 4 into its resting position and the blocking lever 3 into its blocking position as shown in Fig. 1 .

The pawl 2 and the release lever 4 may rotate around the same axis 14. The rotary catch 1 may rotate around its axis 15. The blocking lever 3 may rotate around its axis 16.

There is a further top metal plate 17 above the release lever which holds the axis 1 5 of the rotary catch 1 and the axis 14 of the release lever 4 respectively of the pawl 2 in order to stabilize the locking mechanism. A further biased spring 1 8 pushes the rotary catch into its opened position. A stopper 19 is attached to the side wail 20 of the case comprising the metal plate 5. The stopper 19 stops a turning movement of the rotary catch 1 when the rotary catch turns into its closed position. The stopper 19 is also connected to the top metal plate 17 by a fixing projection 21 on the top side of the stopper 19. Thus, the top metal plate 17 is fixed to the case 5, 20 at least by the stopper 19. The inner cable 22 of a Bowden cable is attached to the end of the release lever 4. The hollow outer cable housing 23 is attached to a further side wall 24 of the case. It is possible to replace the Bowden cable for example by a rod.

The blocking lever 3 comprises three arms which are arranged in a T-like manner. One first arm comprises the lug 1 1 which may rest against the side wall 24 or the hollow outer cable housing 23 as shown in Fig. 1 . A second arm 25 may block the pawl 2 as shown in Fig. 1 . A wedge respectively projection 27 of the release !ever 4 may catch the third arm 26 in order to remove the blocking lever 3 from its blocking position. The wedge respectively projection 27 acts as a cam for the blocking lever. The wedge respectively projection 27 may also act as a cam for the pawl 2 in order to turn the pawl 2 into its locking position.

Both metal plates 5 and 17 are U-shaped in such a manner that a striker can enter the inlet slot 6 of the rotary catch 1 when the rotary catch is in its opened position.

In the locked position , the wedge respectively projection 27 is situated between the arm 26 of the blocking lever 3 and the pawl 2 in such a manner there remains a small gap between the arm 26 of the blocking lever 3 and the projection 27 as indicated by the arrows 28. For this reason, there is a lost motion. A small gap indicated by the arrows 28 may also remain between the release lever 4 and the pawl 2. However, it is also possible that there is no gap between the release lever 4 and the pawl 2 in the locked state and thus no lost motion as shown in greater detail in Fig. 2. The release lever 4 then pushes the pawl 2 into its locking position.

As seen in greater detail in Fig. 2, a locking surface 30 of the catching arm 8 of the rotary catch 1 rests against a step-shaped locking surface 31 of the pawl 2 in the locked position. The locking surface 31 of the pawl 2 is inclined relative to the locking surface 30 of the rotary catch 1 in such a manner that the rotary catch 1 transfers a pivoting moment in a clockwise man ne r into the pawl 2. A blocking surface 32 of the pawl 2 rests against a blocking surface 33 of the arm 25 of the blocking lever 3. The blocking surface 33 of the blocking lever 3 is inclined relative to the blocking surface 32 of the pawl 2 in such a manner that the pawl 2 transfers a pivoting moment in a clockwise manner into the blocking lever 3.

The invention comes with the following benef its :

• Positive pressure angle on both the pawl and the release lever for

allowing a small release effort;

• Strength provided in opening direction by double lever solution (pawl arid blocking lever) ;

• Strength provided in closing direction by frame and cover plates

• Wedge incorporated into the release lever

• Shallow angle between contact force normal and contact to pivot line

• Reaction force to chucking primarily through the release lever pivot

• Reduced number of components

• Reduced overall mass

• Reduced package size

• Reduced release effort with common spring for return and wedging

• Lost motion is implemented between the blocking lever and the release lever.

• To compensate, a positive angle prof ile between the pawl and blocking lever is utilized to seat the comfort pawl into the catch ;

• Lost motion with regard to the release lever provides build variance. The wedging feature of the release lever introduces variability in the release levers resting position.

Fig. 3 shows a second embodiment of the invention . The rotary catch comprises a wedging surface 34. The release lever 4 comprises a wedging post. The wedging post 35 is held against the wedging surface 34 of the rotary catch 1 by the spring 9 when the release lever 4 is in its resting position as shown in figure 3. The wedging surface 34 of the rotary catch 1 has a slight positive pressure to the wedging post 35 to not add to the opening effort while providing a large anti-chucking component vector. When a chucking load is applied to the catch 1 by the seat back through the striker, the rotary catch 1 is prevented from rotating further into the latch by the wedging post 35. The slight rotational moment applied by the positive angle of the wedging surface 34 of the rotary catch 1 to the wedging post 35 is counteracted by the spring 9 to the degree as to limit unpleasant oscillations of the seat back.

The release lever 4 only partially seats the pawl 2 into the rotary catch 1 .

Claims

What is claimed is:

1 . A lock for a motor vehicle seat back comprising a locking mechanism with a rotatably mounted rotary catch for receiving a striker, a pawl with which the rotary catch can be engaged for retaining the striker, a blocking lever capable of blocking the pawl if the latter is located in Its engaging position, a release lever for disengaging the locking mechanism, wherein in a locked state, the rotary catch transfers an opening moment onto the pawl and wherein the blocking lever and the release lever are

interconnected by a spring which pushes the blocking lever into its blocking position and the release lever into its resting position.

2. The lock according to claim 1 wherein the rotary catch, pawl and blocking lever are situated in the same plane.

3. The lock according to any one of claims 1 or 2 wherein the release lever is situated above the pawl.

4. The iock according to any one of claims 1 -3 wherein the spring pushes the release lever into its resting position and the blocking lever into its blocking position.

5. The lock according to any one of claims 1 -4 wherein a leg of the spring rests against a hook-shaped pin of the release lever in a pre-stressed manner.

6. The lock according to any one of claims 1 -4 wherein a leg of the spring rests against a lug of the blocking lever.

7. The lock according to any one of claims 1 -8 wherein the pawl and the release lever are mounted by the same axis.

8. The lock according to any one of claims 1 -7 wherein the spring surrounds an axis of the pawl and the release lever.

9. The lock according to any one of claims 1 -8 wherein the locking

mechanism is situated between a case and a top metal plate.

10. The lock according to any one of ciaimsl -9 wherein a stopper is attached to a side wall of the case and wherein the stopper stops a turning movement of the rotary catch when the rotary catch turns into its closed position.

11. The lock according to the preceding claim wherein the stopper is

connected to the top metal plate.

12. The lock according to any one of claims 1 -1 1 wherein the blocking lever prevents the pawl rotating from an opening moment induced by the rotary catch . .

13. The lock according to any one of claims 1 -1 2 wherein a Bowden cable or rod is attached to the release lever.

14. The lock according to any one of claims 1 -13 wherein the blocking lever comprises three arms.

15. The lock according to any one of claims 1 -14 wherein a wedging post of the release lever is held against a wedging surface of the rotary catch when the release lever is in its resting position.

16. The lock according to any one of claims 1 -15 wherein the release lever comprises a wedge or a release projection which may remove the blocking lever from its blocking position.

17. The lock according to the preceding claim wherein th e wedge or the release projection may turn the pawl into its locking position.

18. The lock according to any one of claims 16-17 wherein the wedge or the release projection is situated between the pawl and an arm of the blocking lever.

19. The lock according to the preceding claim wherein a gap may remain between the arm of the blocking lever and the wedge or release projection.

The lock according to any one of claims 1 - 19 wherein in a locked state, the pawl transfers an opening moment onto the blocking lever.