Patent ID: 8002098

Claim:
A torque responsive release clutch for a power nutrunner, comprising: a first clutch half and a second clutch half, both provided with axially extending teeth for torque transfer between the clutch halves, wherein: either one of said first and second clutch halves is axially movable between an engagement position and a release position, a spring unit is arranged to bias the movable clutch half towards the engagement position, each one of the teeth on said first clutch half has a substantially prismatic shape and extends from a base portion to a top portion, said base portion having a radial extent between an inner diameter and an outer diameter, each one of the teeth on said first clutch half comprises a ridge extending from said base portion at said inner diameter to said top portion at said outer diameter, and each one of the teeth of said second clutch half is arranged to engage a corresponding tooth of said first clutch half at an engagement point that travels along said ridge of said corresponding tooth of said first clutch half when the movable clutch half is displaced from the engagement position to the release position, whereby the engagement point between each tooth of said first clutch half and each tooth of said second clutch half is displaced from said inner diameter to said outer diameter during a clutch release sequence.