Latch apparatus and method

• US 6,776,442 B2
• Filed: 10/11/2001
• Issued: 08/17/2004
• Est. Priority Date: 01/09/2001
• Status: Expired due to Fees

• Current Assignee: Strattec Security Corporation
• Original Assignee: Strattec Security Corporation
• Inventors: Edgar, James R.
• Primary Examiner(s): ESTREMSKY, GARY WAYNE
• Application Number:
  US09/975,649
• Publication Number:
  US 20020089188A1
• Time in Patent Office: 1,041 Days
• Field of Search: 292/201, 292/216, 292/DIG.23, 702/64
• US Class Current: 292/216
• CPC Class Codes: E05B 15/0086 Toggle levers toggle fasteners E05C19/14
• CPC Class Codes: E05B 17/007 Devices for reducing friction between lock parts E05B17/08 takes precedence
• CPC Class Codes: E05B 81/04 Electrical electrical circuits E05B81/54
• CPC Class Codes: E05B 81/06 using rotary motors
• CPC Class Codes: E05B 81/16 operating on locking elements for locking or unlocking action
• CPC Class Codes: E05B 85/243 with a bifurcated bolt
• CPC Class Codes: Y10S 292/23 Vehicle door latches
• CPC Class Codes: Y10T 292/1047 Closure
• CPC Class Codes: Y10T 292/1082 Motor

Abstract

In some embodiments of the present invention, a lever is actuatable to unlatch a pawl when the lever is in an unlocked position. When the lever is in a locked position, lever actuation cannot unlatch the pawl. An over-center device coupled to the lever can be used to position the lever in its locked and unlocked positions. In these and other embodiments, the lever is moved away from the pawl when the lever is in a locked position and is moved closer to the pawl when the lever is in an unlocked position. In some embodiments, the lever is pivotable about a pivot point that remains in the same location with respect to the lever in the unlocked and locked positions thereof. Although not required, the pawl is preferably movable by the lever to its unlatched state after the partially or fully-actuated lever has been moved to its unlocked state.

Claims

1. A method of operating a latch assembly having a ratchet releasably engagable with a pawl, the method comprising:

pivoting a lever about a pivot point substantially fixed with respect to the lever and located in a first position with respect to a body of the latch apparatus, the lever incapable of exerting sufficient motive force to release the ratchet from engagement with the pawl when the pivot point is located in the first position;

moving the lever and the pivot point away from the first position with respect to the body of the latch apparatus while the lever remains at least partially actuated;

moving the lever and the pivot point to a second position with respect to the body of the latch apparatus while the lever remains at least partially actuated; and

moving the pawl with the lever to release the ratchet from engagement with the pawl by moving the lever and the pivot point toward the second position.

2. The method as claimed in claim 1, wherein moving the pawl occurs after the pivot point of the lever is moved to the second position.

3. The method as claimed in claim 1, wherein moving the pawl occurs while the lever is moved and while the lever remains pivoted.

4. The method as claimed in claim 1, wherein moving the lever to move the pivot point to the second position includes translating the lever with respect to the pawl.

5. The method as claimed in claim 1, wherein moving the lever to move the pivot point to the second position includes rotating the lever with respect to the pawl.

6. The method as claimed in claim 1, wherein moving the lever to move the pivot point to the second position includes translating and rotating the lever with respect to the pawl.

7. The method as claimed in claim 1, further comprising:

providing an actuator coupled to the lever; and

actuating the actuator to move the lever.

8. The method as claimed in claim 1, further comprising an over-center device coupled to the lever, the over-center device movable between two stable positions corresponding to the first and second positions of the pivot point.

9. A latch assembly, comprising:

a pawl having;

an unlatched position; and

a latched position;

a lever movable with respect to the pawl;

a rotatable member coupled to the lever and mounted for rotation about an axis, wherein

the lever is movable by rotation of the rotatable member coupled thereto, the rotatable member rotatable between;

a first position in which the lever is actuatable to move the pawl to the unlatched position;

a second position in which actuation of the lever is incapable of generating movement of the pawl to the unlatched position, movement of the rotatable member from the second position to the first position during actuation of the lever generating movement of the pawl; and

the rotatable member is part of an over-center device coupled to the lever.

10. The latch assembly as claimed in claim 9, wherein the lever is movable between an unlocked position and a locked position corresponding to the first and second positions of the rotatable member, respectively, the lever pivotable about substantially the same location with respect to the lever in the unlocked and locked positions.

11. The latch assembly as claimed in claim 9, wherein:

the rotatable member is a first rotatable member; and

the lever is coupled to the first rotatable member by a second rotatable member coupled to the lever and to the first rotatable member.

12. The latch assembly as claimed in claim 11, wherein:

first and second connections are defined between the lever and the second rotatable member and between the second rotatable member and the first rotatable member, respectively; and

at least one of the first and second connections is a lost-motion connection.

13. The latch assembly as claimed in claim 9, wherein the lever is rotatably coupled to the rotatable member.

14. The latch assembly as claimed in claim 9, wherein:

the lever is coupled to a first end of the rotatable member, and

the rotatable member is rotatable about a second end opposite the first end.

15. The latch assembly as claimed in claim 9, wherein the first position of the rotatable member is one of a range of positions of the rotatable member in which the lever is actuatable to move the pawl to the unlatched position.

16. The latch assembly as claimed in claim 9, wherein the second position of the rotatable member is one of a range of positions of the rotatable member in which the lever is incapable of generating movement of the pawl to the unlatched position.

17. The latch assembly as claimed in claim 9, wherein the lever is incapable of moving the pawl in the second position of the rotatable member.

18. A latch assembly, comprising:

a pawl movable between a latched position and an unlatched position;

a lever having

at least one unlocked position in which the lever is actuatable to move the pawl to the unlatched position; and

at least one locked position in which the lever is incapable of moving the pawl to the unlatched position;

an over-center device coupled to the lever at a first pivot and moveable about a second pivot, the over-center device having

a first stable position in which the lever is positioned in the unlocked position by the over-center device with respect to the pawl;

a second stable position in which the lever is positioned in the locked position by the over-center device with respect to the pawl; and

at least one unstable position located between the first and second stable positions, the at least one unstable position located along a line extending through the first and second pivots when the over-center device is in either stable position, wherein actuation of the lever urges the over-center device away from the unstable position and toward either of the first and second stable positions.

19. The latch assembly as claimed in claim 18, further comprising a ratchet releasably engagable with the pawl and having latched and unlatched positions corresponding to the latched and unlatched positions of the pawl.

20. The latch assembly as claimed in claim 19, wherein the first pivot is located in substantially the same location with respect to the lever in at least one unlocked position of the lever and in at least one locked position of the lever.

21. The latch assembly as claimed in claim 18, wherein the over-center device includes a first element and a second element pivotably coupled to one another at a third pivot, the first element also coupled to the lever.

22. The latch assembly as claimed in claim 21, wherein the first element is pivotably coupled to the lever at the first pivot.

23. The latch, assembly as claimed in claim 22, wherein:

the second element is pivotable about the second pivot; and

the first and second stable positions and the at least one unstable center position is defined by different pivotal positions of the first element with respect to the second element.

24. The latch assembly as claimed in claim 18, wherein the first and second stable positions are on opposite sides of the line.

25. The latch assembly as claimed in claim 21, wherein the first and second elements are pivotably coupled together by a lost-motion connection.

26. The latch assembly as claimed in claim 21, wherein:

the second element is pivotable about the second pivot; and

the latch assembly further comprising an angle between the line extending through the first and second pivot points and a second line extending through the first and third pivot points, the angle having different sizes defined by different relative positions of the first element with respect to the second element, the angle limited to acute angle sizes.

27. The latch assembly as claimed in claim 21, wherein:

the second element has a fourth pivot point about which the second element is pivotable, the fourth pivot point located a distance from the first pivot point, the latch assembly further comprising an angle between a first line extending through the first and second pivot points and a second line extending through the first and fourth pivot points, the angle having different sizes defined by different relative positions of the first element with respect to the second element, the angle limited to obtuse angle sizes.

28. The latch assembly as claimed in claim 21, wherein the second element is movable to cam against the first element.

29. The latch assembly as claimed in claim 21, wherein at least one of the first and second elements has a rotational range limited by at least one stop in at least one of the locked and unlocked positions of the over-center device.

30. The latch assembly as claimed in claim 21, wherein the first and second elements are rotatable through respective ranges of positions limited only by a range of movement of the lever.

31. The latch assembly as claimed in claim 18, wherein the over-center device includes first and second elements movable with respect to one another, the first element coupled to the lever and positioned to ride upon a surface of the second element that is inclined with respect to the first element.

32. The latch assembly as claimed in claim 18, wherein the over-center device includes first and second elements movable with respect to one another, the second element rotatable about a second pivot, the first element coupled to the lever and positioned to ride upon a surface of the second element.

33. A method of operating a latch assembly, comprising:

providing a lever coupled to a pawl and movable with respect to the pawl, the lever having a first position with respect to the pawl in which actuation of the lever is incapable of moving the pawl sufficiently to unlatch the latch assembly;

moving at least a portion of an over-center device about a first pivot from a first stable position toward a center position, the over-center device coupled to the lever at a second pivot, the center position located along a line extending through the first and second pivots;

moving the at least a portion of the over-center device past the center position toward a second stable position;

moving the lever from the first position with respect to the pawl to a second position with respect to the pawl responsive to movement of the at least a portion of the over-center device;

actuating the lever in the second position; and

moving the pawl to unlatch the latch assembly responsive to actuation of the lever in the second position.

34. The method as claimed in claim 33, wherein the lever is moved from the first position with respect to the pawl to the second position with respect to the pawl during movement of the over-center device from the first stable position toward the center position.

35. The method as claimed in claim 33, wherein the lever is moved from the first position with respect to the pawl to the second position with respect to the pawl during movement of the over-center device past the center position toward the second stable position.

36. The method as claimed in claim 33, wherein the over-center device includes first and second elements rotatably coupled to one another, the second element also coupled to the lever, the method further comprising:

rotating the first element of the over-center device;

rotating the second element of the over-center device responsive to rotation of the first element; and

moving the lever responsive to rotating the second element of the over-center device coupled to the lever.

37. The method as claimed in claim 36, further comprising stopping rotation of at least one of the first and second elements of the over-center device by a stop, the over-center device in the first stable position when the at least one of the first and second elements is stopped by the stop.

38. The method as claimed in claim 36, further comprising stopping rotation of at least one of the first and second elements of the over-center device by a stop, the over-center device in the second stable position when the at least one of the first and second elements is stopped by the stop.

39. The method as claimed in claim 33, wherein the over-center device includes a first element movably coupled to a second element, the method further comprising riding the first element upon a surface of the second element inclined with respect to the first element.

40. The method as claimed in claim 33, wherein the over-center device includes a first element movably coupled to a second element, the method further comprising riding the first element upon a surface of the second element as the second element rotates about an axis.

41. The method as claimed in claim 33, wherein actuating the lever includes pivoting the lever about the second pivot.

42. The method as claimed in claim 41, wherein moving the lever includes moving the second pivot with respect to the pawl.

43. The method as claimed in claim 41, wherein the second pivot is located in substantially the same position with respect to the lever in the first and second positions of the lever.

44. The method as claimed in claim 33, wherein the over-center device is biased toward at least one of the first and second stable positions and away from the center position upon movement of the over-center device to a corresponding side of the center position.

45. The method as claimed in claim 33, wherein:

the over-center device has a first element and a second element pivotably coupled to the first element and coupled to the lever;

the first element has a range of pivot positions with respect to the second element, the range of pivot positions including the center position; and

moving the over-center device includes pivoting one of the first and second elements with respect to the other of the first and second elements.

46. The method as claimed in claim 33, wherein:

the over-center device includes a first element pivotably coupled at a third pivot to a second element and pivotable about the first pivot;

the lever is pivotably coupled to the second element at the second pivot,

the method further comprising moving the second pivot point across a line passing through the first and second pivots, the line defining the center position of the over-center device.

47. The method as claimed in claim 33, wherein moving the lever includes at least one of pushing and pulling the over-center device against the lever.

48. The method as claimed in claim 33, wherein moving the lever includes pivoting the lever with respect to the over-center device.