Electronic latch apparatus and method

• US 20030094024A1
• Filed: 10/15/2002
• Published: 05/22/2003
• Est. Priority Date: 03/05/1999
• Status: Active Grant

• Current Assignee: Strattec Security Corporation
• Original Assignee: Strattec Security Corporation
• Inventors: Dimig, Steven J.
• Granted Patent: US 6,848,286 B2
• Time in Patent Office: Days
• US Class Current: 70/277
• CPC Class Codes: E05B 81/90 Manual override in case of power failure
• CPC Class Codes: E05B 83/36 Locks for passenger or like doors
• CPC Class Codes: Y10S 292/27 Disconnectable handle
• CPC Class Codes: Y10T 292/1047 Closure
• CPC Class Codes: Y10T 292/1082 Motor
• CPC Class Codes: Y10T 70/5805 Freely movable when locked
• CPC Class Codes: Y10T 70/7062 Electrical type [e.g., solenoid]

Abstract

A latch assembly, comprising a control element having a pivot point and an actuator. The actuator has a first position in which the control element is engaged by the actuator for pivotal movement about the pivot point and a second position in which the control element is disengaged by the actuator from pivotal movement about the pivot point. The latch assembly further includes a ratchet arranged and configured for rotation with the control element when the control element is engaged by the actuator and for non-rotation when the control element is disengaged by the actuator. A highly preferred embodiment of the invention includes an automatic unlocking circuit powered by a backup power source.

Claims

1. A latch assembly, comprising:

a control lever having

a first pivot point and

a second pivot point;

an engagement element coupled to the control lever in a first position and decoupled from the control lever in a second position, the control lever being pivotable about the first pivot point when the engagement element is in the first position and pivotable about the second pivot point when the engagement element is the second position;

an actuator coupled with the engagement element and having an engaged position in which the engagement element is coupled with the control lever and a disengaged position in which the engagement element is substantially released from the control lever; and

a ratchet responsive to actuation of the control lever when the control lever is in the first position and non-responsive to actuation of the control lever when the control lever is in the second position.

2. The latch assembly as claimed in claim 1, wherein the actuator comprises at least one of a solenoid, an electric motor, a hydraulic cylinder, a pneumatic cylinder, a vacuum actuator and a manually actuated device.

3. The latch assembly as claimed in claim 1, wherein the engagement element is a pin adapted to mate with the control lever.

4. The latch assembly as claimed in claim 3, wherein the pin is coupled to the actuator for connection to and disconnection from the control lever at the first pivot point.

5. The latch assembly as claimed in claim 3, wherein the control lever has an aperture therein for receiving the pin when the actuator is in the engaged position.

6. The latch assembly as claimed in claim 1, wherein the control lever has an end for receiving force applied to the control lever externally of the latch assembly for rotating the control lever.

7. The latch assembly as claimed in claim 1, further comprising a pawl located adjacent to the control lever and the ratchet, the pawl positioned substantially within the latch assembly to contact and be moved by the control lever when the control lever is pivoted about the first pivot point.

8. The latch assembly as claimed in claim 7, wherein the pawl has a first pawl position beside the ratchet and a second pawl position disposed from the ratchet by the control lever.

9. The latch assembly as claimed in claim 8, further comprising a pawl spring biasing the pawl into the first pawl position and away from the second pawl position.

10. The latch assembly as claimed in claim 8, wherein the pawl is in an interfering relationship with rotation of the ratchet when the pawl is in the first pawl position and is free from interference with rotation of the ratchet when the pawl is in the second pawl position.

11. The latch assembly as claimed in claim 7, wherein both the pawl and the control lever are coupled by the engagement element for rotation when the engagement element is in the first position.

12. The latch assembly as claimed in claim 7, wherein the pawl has a bearing surface and the control lever has a bearing surface, the bearing surfaces of the pawl and the control lever being in abutting and force-transmitting relationship when the engagement element is in the first position.

13. The latch assembly as claimed in claim 7, wherein the control lever is substantially incapable of transmitting motive force to the pawl when the engagement element is in the second position.

14. The latch assembly as claimed in claim 7, wherein rotation of the control lever is substantially free from interference with the pawl when the engagement element is in the second position.

15. The latch assembly as claimed in claim 7, wherein the pawl has a cam surface and wherein the control lever has a cam surface positioned to ride upon the cam surface of the pawl when the engagement element is in the first position.

16. The latch assembly as claimed in claim 1, further comprising:

a second control lever having

a third pivot point and

a fourth pivot point;

a second engagement element coupled to the second control lever in a third position and decoupled from the second control lever in a fourth position, the second control lever being pivotable about the third pivot point when the second engagement element is in the third position and pivotable about the fourth pivot point when the second engagement element is in the fourth position;

a second actuator coupled with the second engagement element and having an engaged position in which the second engagement element is coupled with the second control lever and a disengaged position in which the second engagement element is released from the second control lever;

the ratchet being responsive to actuation of the second control lever when the second control lever is in the third position and non-responsive to actuation of the second control lever when the second control lever is in the fourth position.

17. The latch assembly as claimed in claim 16, wherein the first control lever and the second control lever each have a connection point for connecting externally extending linking elements thereto, the first and second control levers being pivotable via force exerted upon the connection point of each lever by the externally extending linking elements.

18. The latch assembly as claimed in claim 16, further comprising at least one lever bias element biasing at least one of the control levers toward the other control lever.

19. The latch assembly as claimed in claim 16, further comprising a lever bias element comprising a lever bias spring connected at one end to the first control lever and at another end to the second control lever to bias the control levers toward each other.

20. A latch assembly, comprising:

a control element having a pivot point;

an actuator having a first position in which the control element is engaged by the actuator for pivotal movement about the pivot point and a second position in which the control element is disengaged by the actuator from pivotal movement about the pivot point; and

a ratchet arranged and configured for rotation with the control element when the control element is engaged by the actuator and for non-rotation when the control element is disengaged by the actuator.

21. The latch assembly as claimed in claim 20, further comprising a pawl disposed between the control element and the ratchet, the pawl having an at rest position and an actuated position in which the pawl is moved by the control element.

22. The latch assembly as claimed in claim 21, further comprising a pawl bias member, the pawl bias member biasing the pawl into the at rest position in the latch assembly.

23. The latch assembly as claimed in claim 21, wherein the control element is a lever having a bearing surface and wherein the pawl has a bearing surface, the control element being capable of exerting motive force upon the pawl via the control element and pawl bearing surfaces when the control element is engaged by the actuator in the first position.

24. The latch assembly as claimed in claim 23, wherein the bearing surface of the control element and the bearing surface of the pawl are in sliding relationship with one another when the actuator is in the second position.

25. The latch assembly as claimed in claim 21, wherein the control element is a lever having a bearing surface and wherein the pawl has a bearing surface, the bearing surface of the control element and the bearing surface of the pawl being in sliding relationship with one another when the control element is not engaged by the actuator.

26. The latch assembly as claimed in claim 21, wherein the control element is a lever having a cam surface and wherein the pawl has a cam surface, the cam surface of the control element positioned to ride upon and transmit motive force to the cam surface of the pawl when the control element is engaged by the actuator in the first position.

27. The latch assembly as claimed in claim 26, wherein the control element is substantially free to rotate without interference from the pawl when the control element is not engaged by the actuator.

28. The latch assembly as claimed in claim 21, wherein the control element is substantially free to rotate without interference from the pawl when the control element is not engaged by the actuator.

29. The latch assembly as claimed in claim 20, wherein the ratchet is coupled with the control element and can be actuated thereby when the control element is engaged by the actuator in the first position.

30. The latch assembly as claimed in claim 20, wherein the pivot point is a first pivot point, and wherein the control element is pivotable about a second pivot point when the control element is released by the actuator.

31. The latch assembly as claimed in claim 30, wherein the control element is capable of exerting force resulting in motion of the ratchet when the control element is engaged by the actuator in the first position, the control element being incapable of exerting force sufficient to move the ratchet into an unlatched state when the control element is substantially released from the actuator in the second position.

32. The latch assembly as claimed in claim 30, further comprising a pawl located adjacent to the control element and the ratchet, wherein the control element is capable of exerting force sufficient to move the pawl from a position in which the pawl interferes with movement of the ratchet to a position in which the pawl does not interfere with movement of the ratchet when the control element is engaged by the actuator in the first position.

33. The latch assembly as claimed in claim 20, further comprising an engagement element controlled by the actuator for placing the engagement element in an engaged position coupled with the control element and in a disengaged position uncoupled from the control element.

34. The latch assembly as claimed in claim 33, wherein the actuator is a solenoid.

35. The latch assembly as claimed in claim 33, wherein the engagement element is a pin removably received within an aperture in the control element, thereby establishing a releasable coupled relationship between the engagement element and the control element.

36. The latch assembly as claimed in claim 35, further comprising a pawl located between the control element and the ratchet.

37. The latch assembly as claimed in claim 20, wherein the control element is a first control element and wherein the actuator is a first actuator, the latch assembly further comprising:

a second control element having a second pivot point; and

a second actuator having a first position in which the second control element is engaged by the second actuator for pivotal movement about the second pivot point and a second position in which the second control element is released by the second actuator from pivotal movement about the second pivot point;

the ratchet being arranged and configured for rotation with the second control element when the second control element is engaged by the second actuator, and for nonrotation when both the first and second control elements are released by the first and second actuators, respectively.

38. A latch assembly, comprising:

a control lever having

a pivot point,

a cam surface,

a first control lever state in which the control lever is pivotable about its pivot point, and

a second control lever state in which motion of the control lever is different than motion of the control lever in the first control lever state;

an actuator having

a first actuator state in which the control lever is placed in the first control lever state and

a second actuator state in which the control lever is placed in the second control lever state; and

a pawl having

a cam surface upon which the cam surface of the control lever abuts, the

pawl being moveable

 

between a latched position and an unlatched position via motion of the control lever cam surface against the pawl cam surface.

39. The latch assembly as claimed in claim 38, wherein the control lever is pivotable about a second pivot point when the control lever is in its second control lever state.

40. The latch assembly as claimed in claim 38, further comprising an engagement element positionable by the actuator in an extended position in which the actuator engages the engagement member with the control lever to define the second control lever state.

41. The latch assembly as claimed in claim 38, wherein the actuators is a solenoid.

42. The latch assembly as claimed in claim 40, wherein the engagement element is a pin adapted to mate with the control lever.

43. The latch assembly as claimed in claim 38, wherein the pin is coupled to the actuator for connection to and disconnection from the control lever at the pivot point.

44. The latch assembly as claimed in claim 42, wherein the control lever has an aperture therein for receiving the pin when the actuator is in the second actuator state.

45. The latch assembly as claimed in claim 38, further including a manual override coupled to at least one of the control lever, the pawl and the actuator.

46. The latch assembly as claimed in claim 45, wherein the manual override comprises a lock.

47. The latch assembly as claimed in claim 45, wherein the manual override comprises a cylinder lock.

48. A method of locking a latch assembly, comprising the steps of:

providing a ratchet;

providing a control lever having an unlocked state and a locked state, the control lever having a first pivot point about which the control lever pivots in the unlocked state;

providing an actuator having a first position and a second position;

maintaining the actuator in the first position, the actuator maintaining the control lever in the unlocked state and coupling the control lever and ratchet; and

moving the actuator from the first position to the second position to release the control lever from the unlocked state to the locked state.

49. The method as claimed in claim 48, wherein the control lever is pivotable about a second pivot point when the control lever is in its locked state.

50. The method as claimed in claim 48, further including the step of moving the control lever to move the ratchet from a latched position to an unlatched position.

51. The method as claimed in claim 48, wherein the actuator comprises a solenoid.

52. A latch assembly, comprising:

a control lever having a pivot point, a first path of motion controlled at least in part by pivotal movement about the pivot point, and a second path of motion different than the first path of motion; and

a pawl mounted for motion with the control lever via contact of the pawl by the control lever in its first path of motion, the pawl being substantially disengaged from motion with the control lever in its second path of motion.

53. A latch assembly, comprising:

an engagement element engageable with a control lever, the control lever having a first path of motion when engaged by the engagement element and a second path of motion when substantially disengaged from the engagement element; and

a pawl mounted for motion with the control lever via contact of the pawl by the control lever in its first path of motion, the pawl being substantially disengaged from motion with the control lever in its second path of motion.

54. A latch system, comprising:

a first electric power source;

a second electric power source; and

a latch assembly electrically coupled to both power sources, the latch assembly including an electronically controlled locking mechanism coupled to receive at least one of an unlocking and a locking signal powered by the second electrical source when at least one electric characteristic of the first electric power source varies beyond a predetermined amount.

55. The latch system as claimed in claim 54, wherein the first power source comprises at least one of a vehicle battery and a vehicle electrical system.

56. The latch system as claimed in claim 54, wherein the second power source comprises at least one of a capacitor, a battery, a generator and an alternator.

57. The latch system as claimed in claim 54, wherein the electrical characteristic comprises at least one of the current and the voltage levels produced by the first power source.

58. The latch system as claimed in claim 54, wherein the unlocking signal is generated without manual intervention.

59. The latch system as claimed in claim 54+, wherein the first electric power source is electrically isolated from the second power source.

60. The latch system as claimed in claim 59, wherein a diode electrically isolates the first power source from the second power source.