Motor driven switch

• US 5,949,157 A
• Filed: 09/11/1997
• Issued: 09/07/1999
• Est. Priority Date: 09/11/1997
• Status: Expired due to Fees

• Current Assignee: Baton Labs, Inc.
• Original Assignee: Baton Labs, Inc.
• Inventors: Hirzel, Edgar A.
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): Zura, Peter
• Application Number:
  US08/927,250
• Time in Patent Office: 726 Days
• Field of Search: 307/10.1, 307/98, 307/112, 307/116, 307/125, 307/139, 318/9, 318/10, 318/65, 318/256, 318/280, 318/671
• US Class Current: 307/116
• CPC Class Codes: H01H 2001/5877 with provisions for direct mounting on a battery pole
• CPC Class Codes: H01H 2003/266 having control circuits for motor operating switches, e.g. controlling the opening or closing speed of the contacts
• CPC Class Codes: H01H 3/26 using dynamo-electric motor for storing energy in a spring motor H01H3/30
• CPC Class Codes: H01H 3/40 using friction, toothed, or screw-and-nut gearing
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence

Abstract

An improved motor driven switch is provided. A control system employs the improved motor-driven switch in series with a battery to disconnect the battery from a load when the energy level of the battery drops to a predetermined level. The system comprises an overdrive circuit to ensure that the motor drives a gear train to sufficiently close a gap between a movable switch plate and contact plates in a switch-closed position to reduce switch contact resistance.

Claims

1. An electrical switching system, comprising:

at least one pair of switch contacts, at least one of which is relatively moveable toward and away from at least one opposing stationary switch contact between switch closed and switch open positions;

said moveable and stationary switch contacts in switch closed position having a first electrically closed position with a first electrical resistance and a second electrically closed position with a second electrical resistance less than said first electrical resistance; and

an electro-mechanical device comprising an overdrive circuit and a drive mechanism constructed and arranged to drive said at least one moveable switch contact against said at least one stationary switch contact for a time after said first electrically closed position to reach said second electrically closed position;

said drive mechanism further constructed and arranged to withstand the forces developed when driving said at least one moveable switch contact against said at least one stationary switch contact;

said first electrically closed position being a position of said at least one movable switch contact and said at least one stationary switch contact when electrical contact is first made between said at least one movable switch contact and said at least one stationary switch contact;

said second electrically closed position being a position of said at least one movable switch contact and said at least one stationary switch contact when said at least one movable switch contact is driven against said at least one stationary switch contact for said time after said first electrically closed position is reached.

2. The electrical switching system of claim 1, wherein said first electrical resistance is greater than about 10 milli-ohms.

3. The electrical switching system of claim 1, wherein said second electrical resistance is less than about 8 milli-ohms.

4. The electrical switching system of claim 1, wherein said second electrical resistance is less than about 5 milli-ohms.

5. The electrical switching system of claim 1, wherein said second electrical resistance is less than about 2 milli-ohms.

6. The electrical switching system of claim 1, wherein said time is greater than about 0.6 seconds.

7. The electrical switching system of claim 1, wherein said time is greater than about 0.75 seconds.

8. The electrical switching system of claim 1, wherein said time is greater than about 0.9 seconds.

9. The electrical switching system of claim 1, wherein said drive mechanism comprises a jack screw and at least one gear, wherein said jack screw is attached to one of said at least one gear by a fillet radius.

10. A method for reducing the electrical resistance across at least one pair of switch contacts in a switch closed position, said at least one pair comprising at least one movable switch contact and at least one opposing stationary switch contact using an electro-mechanical system comprising an overdrive circuit and a drive mechanism for opening and closing said switch contacts, said drive mechanism constructed and arranged to withstand the forces developed when driving said at least one moveable switch contact against said at least one stationary switch contact, the steps comprising:

(a) moving at least one movable switch contact relatively toward at least one opposing stationary switch contact to a first electrically closed position having a first electrical resistance, and then

(b) further moving said at least one movable switch contact against said at least one stationary switch contact for a time after said first electrically closed position to reach a second electrically closed position having a second electrical resistance less than said first electrical resistance.

11. The method of claim 10, wherein said first electrical resistance is greater than about 10 milli-ohms.

12. The method of claim 10, wherein said second electrical resistance is less than about 8 milli-ohms.

13. The method of claim 10, wherein said second electrical resistance is less than about 5 milli-ohms.

14. The method of claim 10, wherein said second electrical resistance is less than about 2 milli-ohms.

15. The method of claim 10, wherein said time is greater than about 0.6 seconds.

16. The method of claim 10, wherein said time is greater than about 0.75 seconds.

17. The method of claim 10, wherein said time is greater than about 0.9 seconds.

18. A switching system, comprising:

at least one pair of contacts, wherein at least one contact of said at least one pair of contacts is movable relatively toward and away from the other contact between switch open and switch closed positions; and

an electro-mechanical system including an overdrive circuit;

said at least one moveable contact of said at least one pair of contacts driven by said electro-mechanical system;

said at least one pair of contacts in switch closed position having an electrical resistance less than about 8 milli-ohms.

19. The switching system of claim 18 in which the electrical resistance across said at least one pair of contacts in switch closed position is less than about 5 milli-ohms.

20. The switching system of claim 18 in which the electrical resistance across said at least one pair of contacts in switch closed position is less than about 2 milli-ohms.

21. In a system for controlling a motor driven switch comprising at least one pair of contacts, said at least one pair of contacts comprising at least one contact movable relatively toward and away from at least one other contact between switch open and switch closed positions, command circuit means responsive to a first condition for generating a first signal and responsive to a second condition for generating a second signal, and control circuit means responsive to said first signal for moving said at least one contact in a switch open position and responsive to said second signal for moving said at least one contact in a switch closed position, the improvement comprising:

an overdrive circuit to move said at least one pair of contacts in switch closed position relatively toward each other to an electrical resistance less than about 8 milli-ohms.

22. The system of claim 21, wherein said electrical resistance across said at least one pair of contacts in switch closed position is less than about 5 milli-ohms.

23. The system of claim 21, wherein said electrical resistance across said at least one pair of contacts in switch closed position is less than about 2 milli-ohms.

24. An electrically-operated switching system, comprising:

at least one pair of contacts, wherein at least one contact of said at least one pair of contacts is movable relatively toward and away from the other contact between switch open and switch closed positions;

a command circuit which in response to a first condition generates a first signal and which in response to a second condition generates a second signal;

a control circuit responsive to said first signal to activate an electromechanical system to move said at least one pair of contacts relatively toward the other contact to a switch closed position and responsive to said second signal to activate the electromechanical system to move said at least one pair of contacts relatively away from the other contact to a switch open position; and

an overdrive circuit responsive to said first signal to activate the electromechanical system to move said at least one pair of contacts in switch closed position relatively toward the other to an electrical resistance of less than about 8 milli-ohms.

25. The electrically-operated switching system of claim 24, wherein said overdrive circuit reduces the electrical resistance across said at least one pair of contacts in switch closed position to less than about 5 milli-ohms.

26. The electrically-operated switching system of claim 24, wherein said overdrive circuit reduces the electrical resistance across said at least one pair of contacts in switch closed position to less than about 2 milli-ohms.

27. A motor driven switching system, comprising:

a reversible motor;

a circuit including an overdrive for operating said motor;

a gear train driven by said motor;

a drive mechanism driven by said gear train including a jack screw rotatable in a stationary threaded member;

at least one pair of switch contacts;

at least one switch contact of said at least one pair of switch contacts moveable by said jack screw between switch open and switch closed positions;

said drive mechanism constructed and arranged to withstand the forces developed when driving said at least one moveable switch contact; and

said at least one pair of said switch contacts in switch closed position having an electrical resistance less than about 8 milli-ohms.

28. The motor driven switching system of claim 27 in which the electrical resistance across said at least one pair of switch contacts is less than about 5 milli-ohms.

29. The motor driven switching system of claim 27 in which the electrical resistance across said at least one pair of switch contacts is less than about 2 milli-ohms.

30. An electrical motor driven switching system, comprising:

a reversible electrical motor;

an electrical circuit including an overdrive for operating the electrical motor;

a gear train driven by the electrical motor;

a drive mechanism driven by the gear train including a jack screw rotatable in a stationary threaded member;

at least one pair of electrical switch contacts; and

at least one electrical switch contact of the at least one pair of electrical switch contacts moveable by the jack screw between switch open and switch closed positions;

the at least one pair of the electrical switch contacts in switch closed position having an electrical resistance less than about 8 milli-ohms.

31. The electrical motor driven switching system of claim 30 in which the electrical resistance across the at least one pair of electrical switch contacts is less than about 5 milli-ohms.

32. The electrical motor driven switching system of claim 30 in which the electrical resistance across the at least one pair of electrical switch contacts is less than about 2 milli-ohms.

33. An electrical switching system, comprising:

at least one pair of electrical switch contacts, at least one of which is relatively moveable toward and away from at least one opposing stationary electrical switch contact between switch closed and switch open positions;

the moveable and stationary electrical switch contacts in switch closed position having a first electrically closed position with a first electrical resistance and a second electrically closed position with a second electrical resistance less than the first electrical resistance; and

an electro-mechanical device comprising an overdrive circuit and a drive mechanism constructed and arranged to drive the at least one moveable electrical switch contact against the at least one stationary electrical switch contact for a time after the first electrically closed position to reach the second electrically closed position;

the first electrically closed position being a position of the at least one movable electrical switch contact and the at least one stationary electrical switch contact when electrical contact is first made between the at least one movable electrical switch contact and the at least one stationary electrical switch contact;

the second electrically closed position being a position of the at least one movable electrical switch contact and the at least one stationary electrical switch contact when the at least one movable electrical switch contact is driven against the at least one stationary electrical switch contact for the time after the first electrically closed position is reached.

34. The electrical switching system of claim 33, wherein the time is greater than about 0.6 seconds.

35. The electrical switching system of claim 33, wherein the time is greater than about 0.75 seconds.

36. The electrical switching system of claim 33, wherein the time is greater than about 0.9 seconds.

37. The electrical switching system of claim 33, wherein the first electrical resistance is greater than about 10 milli-ohms.

38. The electrical switching system of claim 33, wherein the second electrical resistance is less than about 8 milli-ohms.

39. The electrical switching system of claim 33, wherein the second electrical resistance is less than about 5 milli-ohms.

40. The electrical switching system of claim 33, wherein the second electrical resistance is less than about 2 milli-ohms.

41. A method for reducing electrical resistance across at least one pair of electrical switch contacts in a switch closed position, the at least one pair comprising at least one movable electrical switch contact and at least one opposing stationary electrical switch contact using an electro-mechanical system comprising an overdrive circuit and a drive mechanism for opening and closing the electrical switch contacts, the method comprising:

(a) moving at least one movable electrical switch contact relatively toward at least one opposing stationary electrical switch contact to a first electrically closed position having a first electrical resistance; and

then

(b) further moving the at least one movable electrical switch contact against the at least one stationary electrical switch contact for a time after the first electrically closed position to reach a second electrically closed position having a second electrical resistance less than the first electrical resistance.

42. The method of claim 41, wherein the time is greater than about 0.6 seconds.

43. The method of claim 41, wherein the time is greater than about 0.75 seconds.

44. The method of claim 41, wherein the time is greater than about 0.9 seconds.

45. The method of claim 41, wherein the first electrical resistance is greater than about 10 milli-ohms.

46. The method of claim 41, wherein the second electrical resistance is less than about 8 milli-ohms.

47. The method of claim 41, wherein the second electrical resistance is less than about 5 milli-ohms.

48. The method of claim 41, wherein the second electrical resistance is less than about 2 milli-ohms.