Claims
- 1. A bidirectional wrap spring clutch assembly comprising:
- rotatable drive structure,
- rotatable driven structure,
- a helical wrap spring coupled between said drive structure and said driven structure and operable in a wrapped condition for connecting said drive structure to said driven structure by means of frictional surface contact and an unwrapped condition,
- at least one of said drive structure and said driven structure including coaxial cylindrical surfaces receiving said wrap spring in clearance fit coaxially therebetween, and
- control mechanism engageable with said wrap spring for shifting said wrap spring between its engaged and disengaged conditions,
- said control mechanism including energy storage mechanism responsive to relative rotation between said drive structure and said driven structure through more than 180.degree. for moving from a first condition to a second condition to store potential energy and operable in the second condition for returning to the first condition to convert the stored potential energy to kinetic energy to drive said wrap spring to the wrapped condition,
- whereby said wrap spring in its wrapped condition frictionally grips one of said cylindrical surfaces when said input structure is rotating in one direction and frictionally grips said other of said cylindrical surfaces when said drive structure is rotating in said opposite direction.
- 2. The clutch assembly of 1, wherein said coaxial cylindrical surfaces are disposed on said drive structure.
- 3. The clutch assembly of 2, wherein said wrap spring has a first end fixed to said driven structure.
- 4. The clutch assembly of claim 3, and further comprising a cone clutch mechanism including first and second frustoconical members respectively fixed to said drive structure and to a second end of said wrap spring and moveable into and out of wedging engagement with each other for respectively moving said wrap spring to its wrapped and unwrapped conditions.
- 5. The clutch assembly of claim 1, wherein
- said drive structure includes a drive shaft having an axis and adapted to be coupled to a motive source,
- said energy storage mechanism being coupled to said drive shaft and axially and rotatably moveable relative thereto between the first and second conditions,
- said control mechanism including structure engageable by said energy storage mechanism in its second condition for shifting said wrap spring to its unwrapped condition,
- said energy storage mechanism in its second condition being responsive to shifting of said wrap spring to its unwrapped condition for rapidly rotatably and axially moving to its first condition,
- said control mechanism being engageable by said energy storage mechanism as it moves to its first condition to shift said wrap spring to its wrapped condition for delivering said kinetic energy of said energy storage mechanism in an impulse to said driven structure.
- 6. A wrap spring clutch assembly comprising:
- rotatable drive structure,
- rotatable driven structure,
- a helical wrap spring coupled between said drive structure and said driven structure and operable in a wrapped condition for connecting said drive structure to said driven structure by means of said frictional surface contact, and
- control mechanism engageable with said wrap spring for shifting said wrap spring between its wrapped and unwrapped conditions,
- said control mechanism including energy storage mechanism responsive to relative rotation between said drive structure and said driven structure through more than 180.degree. for moving from a first condition to a second condition to store potential energy and operable in the second condition for returning to the first condition to convert the stored the potential to kinetic energy to drive said wrap spring to its wrapped condition.
- 7. The clutch assembly of claim 6, wherein said wrap spring has a first end fixed to said driven structure.
- 8. The clutch assembly of claim 7, and further comprising a cone clutch mechanism including first and second frustoconical members respectively fixed to said drive structure and to a second end of said wrap spring and movable into an out of wedging engagement with each other for respectively moving said wrap spring to its wrapped and unwrapped conditions.
- 9. The clutch assembly of claim 6, wherein said drive structure includes a drive shaft having an axis and adapted to be coupled to a motive source, said energy storage mechanism being coupled to said drive shaft and axially and rotatably movable relative thereto between the first and second conditions, said control mechanism including structure engageable by said energy storage mechanism in its second condition for shifting said wrap spring to its unwrapped condition, said energy storage mechanism in its second condition being responsive to shifting of said wrap spring to its unwrapped condition for rapidly rotatably and axially moving to its first condition, said control mechanism being engageable by said energy storage mechanism as it moves to its first condition to shift said wrap spring to its wrapped condition for delivering said kinetic energy of said energy storage mechanism in an impulse to said driven structure.
Parent Case Info
This is a divisional of application Ser. No. 08/754,702, filed Nov. 21, 1996.
US Referenced Citations (29)
Divisions (1)
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Number |
Date |
Country |
Parent |
754702 |
Nov 1996 |
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