Brake

In a rotary power transmitting system:

• a stationary reaction annulus having internal teeth therearound;
• a rotatable drive member concentric with said annulus;
• a rotatable driven member axially aligned with the drive member;
• a pawl swingably mounted on the driven member for movement toward and away from the reaction teeth;
• a driver surface located on the drive member to rotate around the drive member axis, an abutment located on said driven member in the path of the drive member surface so that power transmission takes place only when the driver surface is forcibly engaged with the abutment;
• a cam surface located on the drive member remote from the driver surface, and a cooperating follower surface located on the pawl, whereby initial rotary movement of the drive member causes the cam surface to exert pressure on the follower surface for thus swinging the pawl out of engagement with the associated reaction teeth;
• said abutment being oriented to the pawl and driver surface so that the driver surface forcibly engages the abutment only after the pawl has been disengaged from the reaction teeth;
• and spring means yieldably trained between the drive member and pawl so that the pawl is biased toward a condition engaged with the reaction teeth and cam surface, whereby when the drive member is put in a non-powered condition the spring means moves the pawl into engagement with the teeth and also moves the drive member so that the driver surface is spaced from the abutment;
• the swing axis of the pawl located so that the tooth-engaging surface of the pawl moves generally parallel to the load surfaces of the reaction teeth during movement of the pawl toward and away from the teeth.