Patent ID: 8109373

Claim:
A pumping device for controlling rotation and locking of a shaft, comprising: a support plate having a hole through which the shaft passes; a ring-shaped cam receiver accommodated in the support plate to be supported; a brake cam received in the cam receiver to be integrally rotated with the shaft, and defining a plurality of receiving spaces between the brake cam and an inner circumferential surface of the cam receiver at regular intervals in a circumferential direction; locking means received in each receiving space to allow and prevent rotation of the brake cam in the cam receiver depending upon whether or not pushing force is applied to the locking means in the circumferential direction; a control plate for applying the pushing force to the locking means in the circumferential direction through rotation thereof; a bidirectional clutch held in a state of being coupled to the control plate if clockwise or counterclockwise rotating force is applied thereto, and returned to a state of being decoupled from the control plate if the rotating force is not applied thereto; a cover plate assembled with the support plate so that the cam receiver, the brake cam, the locking means, the control plate, and the bidirectional clutch are received in a space defined between the support plate and the cover plate; a lever plate provided outside the cover plate, having a hole through which the shaft passes, and applying the clockwise or counterclockwise rotating force to the bidirectional clutch; and elastic returning means for returning the lever plate to a predetermined reference position, wherein the bidirectional clutch includes a clutch cam which rotates about the shaft upon application of the rotating force from the lever plate, a locking gear slid by the rotating clutch cam from a decoupled position, in which the locking gear is decoupled from the control plate, to a coupled position, in which the locking gear is coupled to the control plate, and elastic pressing means for pressing the locking gear toward the decoupled position; and the control plate is formed with teeth to be coupled with the locking gear, and wherein the bidirectional clutch further includes a guide plate which has a guiding part for guiding sliding movement of the locking gear and a supporting part for supporting the elastic pressing means.