US Patent 8979506 Reverse rotation prevention device

Apparatus and methods to prevent the rotation of a shaft in one direction using a device comprising a collar disposed around the shaft, a locking arm with an unlocked position and a locked position, and an actuator capable of moving the locking-arm between the unlocked and locked position. When the locking arm is in the unlocked position, the collar and shaft are allowed to rotate in a first direction. However, when the locking arm is in the locked position, the collar and shaft are prevented from rotating in a second direction. This device can also be used to prevent the reverse rotation of a rotating compressor.