Patent ID: 7225707

Claim:
A rotary torque wrench comprising: a rotary actuator having a drive shaft and a quick change attachment flange with an opening provided for the drive shaft of the rotary actuator; a planetary gear set attached to an adapter collar having an opening for a first stage input gear shaft of the planetary gear set and a cylindrical axial channel disposed radially outward from the opening; means for quickly engaging and disengaging the adapter collar to the quick change attachment flange to provide an axial locking attachment of the gear set to the rotary actuator without the use of tools, while maintaining rotational freedom between the gear set and the rotary actuator; wherein the planetary gear set removably attaches to the rotary actuator, creating a mechanical connection of the rotary actuator drive shaft to the first stage input gear shaft of the gear set for torque transmission of the rotary actuator to the gear set; wherein the quick change attachment flange includes a base having a base inner circumference, a base outer circumference, and an inner periphery extending from the base inner circumference, the inner periphery having a plurality of through bores defined therein extending radially and converging inward to an axial center line of the inner periphery, the inner periphery having for each through bore a corresponding, concentric counter bore of a predetermined depth and greater diameter than the through bore; a compression spring disposed within each counter bore, each compression spring being supported by a shoulder formed by the corresponding counter bore and through bore; an engagement pin disposed inside the combination of the compression spring, counter bore and through bore; a rotatable locking collar having a plurality of cam lobes disposed on an inner circumference of the rotatable locking collar, the rotatable locking collar resting atop the base of the quick change attachment flange and fitting concentrically outside and proximate to the inner periphery; and wherein a removable attachment of the gear set to the actuator is obtained by rotating the rotatable locking collar, thereby causing the cam lobes to push the compression spring-loaded engagement pins to penetrate the plurality of through bores and into the cylindrical axial channel of the adapter collar when the adapter collar has been inserted concentrically inside of and proximate to the inner periphery.