Yieldable gearing and safety mechanisms for garage door operators

• US 5,557,887 A
• Filed: 10/28/1994
• Issued: 09/24/1996
• Est. Priority Date: 06/29/1994
• Status: Expired due to Fees

• Current Assignee: Jerry W. Fellows
• Original Assignee: Jerry W. Fellows
• Inventors: Fellows, Jerry W., Davis, Richard S., Sherlock, Thomas M.
• Primary Examiner(s): KANNAN, PHILIP
• Application Number:
  US08/330,479
• Time in Patent Office: 697 Days
• Field of Search: 49/28, 49/26, 49/139, 49/140, 49/360, 49/199, 49/200, 318/807, 318/798, 318/727, 160/188, 160/189, 324/1 NQ, 340/514, 340/515
• US Class Current: 49/28
• CPC Class Codes: E05F 15/41 Detection by monitoring transmitted force or torque E05F15/48 takes precedence; Safety couplings with activation dependent upon torque or force, e.g. slip couplings
• CPC Class Codes: E05F 15/603 using rotary electromotors
• CPC Class Codes: E05F 15/668 for overhead wings
• CPC Class Codes: E05Y 2201/214 Disengaging means
• CPC Class Codes: E05Y 2201/236 using force or torque
• CPC Class Codes: E05Y 2201/238 reaction force or torque
• CPC Class Codes: E05Y 2201/716 Pinions
• CPC Class Codes: E05Y 2400/504 of control
• CPC Class Codes: E05Y 2400/514 of speed
• CPC Class Codes: E05Y 2400/554 sensing motor load
• CPC Class Codes: E05Y 2800/21 of identical elements, e.g. of identical compression springs
• CPC Class Codes: E05Y 2800/22 of not identical elements of the same category, e.g. combinations of not identical springs
• CPC Class Codes: E05Y 2900/106 for garages
• CPC Class Codes: H02H 3/05 with means for increasing reliability, e.g. redundancy arrangements for logic circuits H03K19/003
• CPC Class Codes: H02H 7/0851 for motors actuating a movable member between two end positions, e.g. detecting an end position or obstruction by overload signal
• CPC Class Codes: H02H 7/0853 specially adapted for motors rotating in both directions H02H7/0851 takes precedence

Abstract

A garage door operator which senses obstructions and takes corrective action before entrapment can occur. Yieldable gears are utilized as a failsafe mechanism such that when the applied torque exceeds certain limit, the gears disengage so that the garage door can be manually moved. The yieldable gears may also be disengaged by remote control or by hand. Solid state circuitry is provided to achieve soft starts and stops of the electric motor. Test circuitry is provided that tests the operational readiness of the electrical components by simulating an abnormal torque condition. During operation of the electric motor, the torque load is electronically calculated and if an abnormal torque load is encountered, the electric motor reverses direction.

Claims

1. An actuator for operating a garage door, said actuator coupled to a door opening and closing mechanism, said actuator comprising:

a motor;

a transmission, coupled to said motor and said garage door opening and closing mechanism, that transmits force from said motor to said door opening and closing mechanism to close said garage door; and

means, coupled to said transmission, for disengaging a portion of said transmission when the torsional force to close said garage door reaches a predetermined limit;

whereby said disengaged transmission no longer transmits force from said motor to said door opening and closing mechanism and said motor offers no resistance to manually lifting said garage door.

2. The actuator of claim 1, wherein said transmission includes first and second gears, said first and second gears being engaged to transmit force from said motor to said door opening and closing mechanism, and said disengaging means separates said first and second gears when the torsional force reaches said predetermined limit.

3. The actuator of claim 2, further comprising a means for retaining said second gear engaged with said first gear.

4. The actuator of claim 2, wherein said first and second gears are crown gears.

5. The actuator of claim 4, wherein the teeth of said first and second crown gears are at an angle of 20°

-30°

.

6. The actuator of claim 4, further comprising:

a shaft having a portion with an external surface having a consistent multi-sided cross-sectional shape;

said second crown gear being hollow having an internal surface, said internal surface having said cross-sectional shape;

said internal surface of second crown gear being mated to said portion of said shaft so that said second crown gear and said shaft are rotatably connected.

7. The actuator of claim 6, wherein said cross-sectional shape is square.

8. The actuator of claim 2, wherein said second gear is mounted on a yoke, said yoke being coupled to said disengaging means and rotatable to a position where said second gear disengages said first gear when the torsional force reaches said predetermined limit.

9. The actuator of claim 2, further comprising a lever, said lever being coupled to said second gear to disengage said first and second gears.

10. The actuator of claim 9, further comprising a solenoid, said solenoid being coupled to said lever such that activation of said solenoid causes said first and second gears to disengage.

11. The actuator of claim 10, further comprising a battery for supplying power to said solenoid.

12. The actuator of claim 11, further comprising a controller coupled to said solenoid and said battery, said controller activating said solenoid in response to a command to open said garage door when there is insufficient power for said motor to open said garage door.

13. The actuator of claim 1, further comprising a circuit that provides power to said motor, said circuit comprising:

an alternating current source;

a detector, coupled to said alternating current source, for detecting when said alternating current crosses zero;

a triac switch, coupled between said alternating current source and said motor, for selectively connecting said alternating current source to said motor;

a triac control circuit, coupled to said triac switch, for switching said triac switch to connect said alternating current source to said motor; and

a means, coupled to said detector and said triac control circuit, for directing the operation of said triac control circuit after said alternating current crosses zero in order to vary the power applied to said motor.

14. The actuator of claim 1, further comprising a circuit for testing the ability of the actuator to electrically detect an overload torque condition, said circuit comprising:

an impedance approximating the resistance of said motor at an abnormal load;

a means, coupled to said impedance, for determining the current drawn by said impedance;

a means, coupled to said impedance, for applying a voltage to said impedance that would generate an overload torque condition in said motor; and

a control circuit, coupled to said determining means and said applying means, for controlling the application of voltage to said impedance, receiving the value of the current drawn from said determining means, and preventing said actuator from operating if an overload torque condition fails to be detected with a predetermined time period.

15. The actuator of claim 1, wherein said door opening and closing mechanism comprises:

a rail, said rail having at least one hole and said garage door moving between an up and down position along said rail;

a pin, said pin being reciprocatingly placed in said at least one hole to prevent said garage door from moving along said rail; and

a solenoid, said solenoid operably coupled to said pin to reciprocatingly move said pin.

16. The actuator of claim 15, further comprising a battery for supplying power to said solenoid.

17. The actuator of claim 16, further comprising a controller coupled to said solenoid and said battery, said controller activating said solenoid in response to a command to open said garage door when there is insufficient power for said motor to open said garage door.

18. The actuator of claim 1, wherein:

during garage door closure, said actuator reverses the movement of said garage door if an obstruction is detected; and

said actuator closes said garage door when said obstruction is no longer detected.

19. An actuator for operating a garage door, comprising:

a motor;

a drive shaft;

a first crown gear coupled to said motor;

a second crown gear coupled to said drive shaft, said second crown gear being movable from a first position engaged with said first crown gear and a second position disengaged with said first crown gear; and

a detent, coupled to said second crown gear, that retains said second crown gear in said first position and allowing said second crown gear to move to said second position when the torsional force between said first and second crown gears reaches a predetermined limit.

20. The actuator of claim 19, wherein the teeth of said first and second crown gears are at an angle of 20°

-30°

.

21. The actuator of claim 19, wherein:

said drive shaft has a portion with an external surface having a consistent multi-sided cross-sectional shape;

said second crown gear being hollow having an internal surface, said internal surface having said cross-sectional shape;

said internal surface of second crown gear being mated to said portion of said shaft so that said second crown gear and said driving shaft are rotatably connected.

22. The actuator of claim 21, wherein said cross-sectional shape is square.

23. The actuator of claim 19, further comprising a lever coupled to said second crown gear such that movement of said lever moves said second crown gear between said first position and said second position.

24. The actuator of claim 23, further comprising a solenoid, said solenoid being coupled to said lever such that activation of said solenoid causes said second crown gear to move from said first position to said second position.

25. An actuator for operating a garage door, comprising:

a motor;

a first gear coupled to said motor;

an intermediate shaft having a second and third gear;

a yoke supporting said intermediate shaft, said yoke being able to rotate said intermediate shaft from a first position where said first gear engaged with said second gear to a second position where said first gear is disengaged from said second gear;

a drive shaft having a fourth gear, said fourth gear engaging said third gear; and

a detent, coupled to said intermediate shaft, that retains said intermediate shaft in said first position and allowing said intermediate shaft to move to said second position when the torsional force between said third and fourth gears reaches a predetermined limit.

26. The actuator of claim 25, wherein the axis of rotation of said yoke is the same as the axis of rotation of said fourth gear and different than the axis of rotation of said first gear.

27. The actuator of claim 25, further comprising a lever coupled to said intermediate shaft such that movement of said lever moves said intermediate shaft between said first position and said second position.

28. The actuator of claim 27, further comprising a solenoid, said solenoid being coupled to said lever such that activation of said solenoid causes said intermediate shaft to move from said first position to said second position.

29. In an actuator for operating a garage door having a motor, a worm gear coupled to said motor, a helical gear coupled to said worm gear, and a drive shaft coupled to said helical gear, the improvement comprising:

a first crown gear coupled to said helical gear; and

a second crown gear coupled to said drive shaft, said second crown gear movable from a first position engaged with said first crown gear to a second position disengaged with said first crown gear when the torsional force between said first and second crown gears reaches a predetermined limit;

whereby said motor no longer transmits force to said drive shaft when said first and second crown gears are disengaged.

30. A garage door operator, comprising:

a garage door;

a rail, said garage door moving between an up and down position along said rail;

a pin, said pin being reciprocatingly placed in said rail to prevent said garage door from moving along said rail;

a solenoid, said solenoid operably coupled to said pin to reciprocatingly move said pin; and

a means for remotely controlling said solenoid.

31. The garage door operator of claim 30, further comprising a battery for supplying power to said solenoid.

32. A garage door actuator for opening and closing a garage door, comprising:

a motor; and

a transmission, coupled to said motor, that transmits force to open and close said garage door, said transmission disengaging when the force to close said garage door reaches a predetermined limit so that said motor offers no resistance to manually lifting said garage door.

33. The actuator of claim 32, wherein said transmission includes a pair of yieldable gears.

34. The actuator of claim 33, wherein said pair of yieldable gears are crown gears mounted on a shaft.

35. The actuator of claim 33, wherein one of said pair of yieldable gears is mounted on a yoke that is rotatable to a position where said pair of yieldable gears are disengaged.

36. A garage door actuator for opening and closing a garage door, comprising:

a rail, said garage door moving between an up and down position along said rail;

a pin, said pin being reciprocatingly placed in said rail to prevent said garage door from moving along said rail;

a solenoid, said solenoid operably coupled to said pin to reciprocatingly move said pin; and

a means for remotely controlling said solenoid.