Torque limiting device for air impact tool
First Claim
1. A torque limiting mechanism comprising:
- two coaxial shafts having an axis of rotation, a rigid torque member coupled to one of said shafts and having a peripheral drive surface including a plurality of drive surface portions, a plurality of flexible and resilient torque members coupled to the other of said shafts for engagement with said peripheral drive surface, threaded cylindrical retaining means encircling said resilient torque members and disposed in engagement therewith for holding said resilient torque members in engagement with said peripheral drive surface with a predetermined force for preventing rotation of said resilient torque members and said rigid torque member relative to each other about said axis at torques below a predetermined torque, said retaining means having a sloping engagement portion shaped and dimensioned substantially to make point contact with each of said resilient torque members longitudinally thereof, said resilient torque members being yieldable at said predetermined torque and above to accommodate relative rotation between said resilient torque members and said rigid torque member, an adjusting member encircling said resilient torque members and disposed in threaded engagement with said cylindrical retaining means, and means coupled to said adjusting member for accommodating rotation thereof about said axis while preventing axial movement thereof, thereby to effect axial movement of said cylindrical retaining means relative to said resilient torque members for varying said predetermined force to vary the torque at which said resilient torque members will yield.
5 Assignments
0 Petitions
Accused Products
Abstract
An air impact tool has an air motor driving a rotary impact mechanism which has a drive shaft which is coupled to a coaxial load shaft through a torque-limiting clutch mechanism which includes a rigid torque member coupled to one of the shafts and having a peripheral drive surface with drive surface portions, and a yieldable torque member coupled to the other shaft. A plurality of flexible and resilient arms on the yieldable torque member are equiangularly spaced apart around the axis of rotation parallel thereto and are cantilevered from a support yoke, the distal ends of the arms being respectively engaged with the drive surface portions of the torque receiving member. A retaining cylinder encircles the arms and holds them against the drive surface, the retaining cylinder being threadedly engaged with an adjusting member which is rotatable but axially fixed to effect axial movement of the retaining cylinder to vary the retaining force on the torque transmitting arms. Embodiments showing internally and externally threaded retaining cylinders, and planar and concave drive surface portions are disclosed.
60 Citations
20 Claims
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1. A torque limiting mechanism comprising:
two coaxial shafts having an axis of rotation, a rigid torque member coupled to one of said shafts and having a peripheral drive surface including a plurality of drive surface portions, a plurality of flexible and resilient torque members coupled to the other of said shafts for engagement with said peripheral drive surface, threaded cylindrical retaining means encircling said resilient torque members and disposed in engagement therewith for holding said resilient torque members in engagement with said peripheral drive surface with a predetermined force for preventing rotation of said resilient torque members and said rigid torque member relative to each other about said axis at torques below a predetermined torque, said retaining means having a sloping engagement portion shaped and dimensioned substantially to make point contact with each of said resilient torque members longitudinally thereof, said resilient torque members being yieldable at said predetermined torque and above to accommodate relative rotation between said resilient torque members and said rigid torque member, an adjusting member encircling said resilient torque members and disposed in threaded engagement with said cylindrical retaining means, and means coupled to said adjusting member for accommodating rotation thereof about said axis while preventing axial movement thereof, thereby to effect axial movement of said cylindrical retaining means relative to said resilient torque members for varying said predetermined force to vary the torque at which said resilient torque members will yield. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A power tool for applying torque to a load comprising:
motive means for generating torque, two coaxial shafts respectively adapted for coupling to the load and said motive means and having an axis of rotation, and torque-limiting clutch mechanism interconnecting said shafts, said clutch mechanism including a rigid torque member coupled to one of said shafts and having a peripheral drive surface including a plurality of drive surface portions, a plurality of flexible and resilient torque members coupled to the other of said shafts and disposed for engagement with said peripheral surface, threaded cylindrical retaining means encircling said resilient torque members and disposed in engagement therewith for holding said resilient torque members in engagement with said peripheral drive surface with a predetermined force for preventing rotation of said resilient torque members and said rigid torque member relative to each other about said axis at torques below a predetermined torque, said retaining means having a sloping engagement portion shaped and dimensioned substantially to make point contact with each of said resilient torque members longitudinally thereof, said resilient torque members being yieldable at said predetermined torque and above to accommodate relative rotation between said resilient torque members and said rigid torque member, an adjusting member encircling said resilient torque members and disposed in threaded engagement with said cylindrical retaining means, and means coupled to said adjusting member for accommodating rotation thereof about said axis while preventing axial movement thereof, thereby to effect axial movement of said cylindrical retaining means relative to said resilient torque members for varying said predetermined force to vary the torque at which said resilient torque members will yield. - View Dependent Claims (16, 17, 18, 19, 20)
Specification