Lock for a flap or door

Abstract

The invention relates to a lock for a door or flap, comprising a locking mechanism that consists of a rotary latch (1) and at least one pawl (2) for locking the rotary latch (1), the rotary latch (1) when in the detent position preferably initiating an opening moment in the pawl (2). The design of the rotary latch (1) is such that said latch is deformed under excessive stress in the locked state in such a way that an engagement between the pawl (2) and the rotary latch (1) is maintained or increases. A lock of this type will not open even under excessive stress.

Claims

1. A lock for a door or flap comprising a locking mechanism that has an unlocked position and a locked position, the locking mechanism comprising: a rotary latch having a load arm, a predetermined bending point, a collecting arm that is spaced from the load arm and bendable around the predetermined bending point, a stop arm for preventing excessive pivoting of the rotary latch, and an intermediate closed position arm positioned between the collecting arm and the stop arm; and at least one pawl for locking the rotary latch, each of the collecting arm of the rotary latch and the pawl having a locking surface, the locking surface of the collecting arm and the locking surface of the pawl being engageable with one another to form a deformable overlapping surface area when in the locked position, wherein during excessive stressing of the locking mechanism when in the locked position, the collecting arm bends around the bending point and the locking surface of the rotary latch is deformable to maintain or increase the overlapping surface area between the pawl and the collecting arm of the rotary latch to maintain the locking mechanism in the locked position, wherein a distance between the collecting arm and the load arm of the rotary catch increases when the collecting arm bends around the bending point.

2. The lock according to claim 1, wherein the predetermined bending point is arranged on the collecting arm and contains a recess arranged on a side of the collecting arm facing away from a locking bolt of the door or flap in the locked position.

3. The lock according to claim 2, wherein the rotary latch contains at least two recesses and the recesses have equal or different lengths.

4. The lock according to claim 1, wherein at least one material property of the rotary latch is different at the predetermined bending point of the rotary latch as compared with the load arm and the collecting arm.

5. The lock according to claim 1, wherein the rotary latch contains at least one portion having a reduction in thickness.

6. The lock according to claim 5, wherein the reduction in thickness is on at least one side of the rotary latch.

7. The lock according to claim 5, wherein the rotary latch contains at least two portions having a reduction in thickness.

8. The lock according to claim 5, wherein the reduction in thickness has the shape of at least one of a pointed notch, a radius and a U-shape.

9. The lock according to claim 8, further comprising a blocking lever that blocks the pawl in the locked position of the locking mechanism.

10. The lock according to claim 4, wherein the at least one material property includes at least one of elasticity, bending stiffness, and hardness.

11. The lock according to claim 1, wherein the intermediate closed position arm is a bolt connected to the rotary latch.

12. The lock according to claim 1, wherein the predetermined bending point is located between the intermediate closed position arm and the collecting arm.

13. The lock according to claim 1, wherein the pawl contains two lever arms, one of the two lever arms being configured to engage the rotary latch.

14. The lock according to claim 13, wherein the two lever arms are arranged perpendicularly to one another.

15. A lock for a door or flap comprising a locking mechanism that has an unlocked position and a locked position, the locking mechanism comprising: a rotary latch having a load arm, a predetermined bending point, and a collecting arm that is spaced from the load arm and bendable around the predetermined bending point; and at least one pawl for locking the rotary latch, the collecting arm of the rotary latch and the pawl having an overlapping surface area when in the locked position, wherein the pawl contains two lever arms, one of the two lever arms being configured to engage the rotary latch, wherein the two lever arms are arranged perpendicularly to one another, wherein during excessive stressing of the locking mechanism when in the locked position, the collecting arm bends around the bending point to maintain or increase the overlapping surface area between the pawl and the collecting arm of the rotary latch, causing a distance between the collecting arm and the load arm of the rotary catch to increase to maintain the locking mechanism in the locked position.

16. The lock according to claim 15, wherein the predetermined bending point is arranged on the collecting arm and contains a recess arranged on a side of the collecting arm facing away from a locking bolt of the door or flap in the locked position.

17. The lock according to claim 16, wherein the rotary latch contains at least two recesses and the recesses have equal or different lengths.

18. The lock according to claim 15, wherein at least one material property of the rotary latch is different at the predetermined bending point of the rotary latch as compared with the load arm and the collecting arm.

19. The lock according to claim 15, wherein the rotary latch contains at least one portion having a reduction in thickness.

20. The lock according to claim 19, wherein the reduction in thickness is on at least one side of the rotary latch.

Description

(1) FIG. 1 shows: a locking mechanism in its locked state

(2) FIG. 1 shows a locking mechanism of a lock of a motor vehicle, comprising a rotary latch, a pawl 2 and a blocking lever 3 that are rotatably mounted on a lock case 4. The rotary latch 1 can be pivoted around its axis 5. The pawl 2 can be pivoted around its axis 6. The blocking lever 3 can be pivoted around its axis 7. It must be noted that the invention is explained with reference to a lock consisting of several pawls, a so-called multiple pawl locking mechanism. The invention does, however, expressly not only relate to a multiple pawl locking mechanisms but is also applicable to all other locks with a locking mechanism.

(3) Using its locking surface 8, the pawl 2 locks the rotary latch 1, resting with the locking surface 9 of its collecting arms 10 on the locking surface 8 of the pawl. In the example, an arrangement of the locking surface 8, 9 to each other has been chosen that ensures that the rotary latch 1 initiates an opening moment in the pawl 2. As a result of the opening moment, the pawl 2 can be pivoted out of its shown detent position and, in case of FIG. 1 by pivoting in clockwise direction around the axis 6 when the blocking lever 3 is moved out of its blocking position by actuation of an internal or external actuation means.

(4) The rotary latch 1 contains a collecting arm 10 and a load arm 11. The collecting arm 10 contains a predetermined bending point 12. The tapered area can be provided in form of a preferably curved recess extending from one side or, as shown, from both sides of the collecting arm. When an excessive force as for instance in case of a crash is exerted on the locking bolt 13 held by the rotary latch 1 and the load arm 11 is thus pulled in the opening direction, the collecting arm 10 bends around the predetermined bending point 12 as a result of the predetermined bending point 12 and in relation to load arm 10 in counterclockwise direction. This deformation can be plastic and/or elastic. As a result, the contact point between the locking surface 9 and locking surface 8 is moved in such a way that the overlap of locking surfaces 8 and 9 is increased.

(5) The rotary latch 1 contains an arm 14, extending into a plane located above the plane on which the bases of the rotary latch 1 and of the pawl 3 are located. Above pawl 2 a release lever—not shown—is provided on the axis 6 that also operates as an intermediate closed position pawl. In the intermediate closed position this arm 14 rests against the intermediate closed position pawl so that the locking mechanism can also be locked in an intermediate closed position. In this example of the embodiment the intermediate closed position arm 14 is a folded edge formed integrally with the rotary latch 1. It is, however, also possible to use an intermediate closed position arm 14 that is a separate bolt connected to the rotary latch 1. The rotary latch 1 can also contain an arm 15 that can, for instance, be moved against a stop in order to prevent excessive pivoting of the rotary latch.

(6) The collecting arm 10 does not necessarily have to contain a tapered area, i.e. a recess 12 in order to be deformed in the desired manner. Alternatively also one or two recesses can be provided on one or both sides of the rotary latch. As a further alternative or, in addition, the rotary latch can also have undergone heat treatment, in order to form a predetermined bending point. It is therefore particularly important that the rotary latch is designed in such a way that in case of excessive stressing by the locking bolt 13, the rotary latch is deformed in such a way that the overlap of locking surfaces 8 and 9 is at least not reduced. Preferably, the overlap is even increased in case of excessive stressing. FIG. 1 shows a pretensioned leg spring 16, able to move the blocking lever 3 in the direction of the blocking position. The blocking lever 3 must be pivoted in counterclockwise direction and against the force of this spring 16 around its axis 7, in order to open the locking mechanism. The blocking lever 3 and pawl 2 are designed in such a way that the blocking lever 3 can move the pawl 2 into its detent position. A stop 17 mounted on lock case 4 prevents the pawl 2 from being moved in counterclockwise direction past its detent position.

(7) In a further advantageous embodiment, a recess 18 is additionally or exclusively provided that is arranged in the collecting arm 10 of the rotary latch 1 on the side facing the locking bolt 13. This produces a relatively long physically effective lever without having to increase the overall design accordingly and in comparison to the scenario in which a recess in form of an indentation is provided on the side facing away from the locking bolt. In case of excessive stressing of the lever, the overlap then increases significantly. An indentation exists where starting from the open position, the locking bolt has to be moved over a step-like section 19 of the contour of the collecting arm 10, in order to move into the closed position shown in FIG. 1.

LIST OF REFERENCE NUMBERS

(8) 1: Rotary latch 2: Pawl 3: Blocking lever 4: Lock case 5: Pawl axis 6: Common axis of pawl and release lever 7: Blocking lever axis 8: Locking surface of pawl 9: Locking surface of rotary latch 10: Collecting arm 11: Load arm 12: Predetermined bending point 13: Locking bolt 14: Arm for locking in intermediate closed position 15: Arm 16: Leg spring 17: Stop for blocking lever 18: Indentation 19: Step-like contour