ANTI-STALL MECHANISM

摘要

The subject matter of this specification can be embodied in, among other things, a locking clutch that includes a collection of movable locking blocks slidably coupled to the rotatable output shaft. The movable locking blocks slide radially inwardly and outwardly with respect to a central longitudinal axis of the rotatable output shaft, and are spaced apart circumferentially about the rotatable output shaft, with each movable locking block having a first contacting face and a second contacting face. A collection of fixed locking blocks are coupled to the rotatable housing, and are positioned radially around the output shaft and spaced apart circumferentially about the interior of the rotatable housing a distance sufficient to receive one of the movable locking blocks when it moves inwardly toward the central axis of the rotatable output shaft, each said fixed locking block having a first contacting face and a second contacting face.