| 摘要 |
A pneumatic control system for a meat trimming knife in which an annular cutting blade of the knife is rotated by a flexible cable driven by an electric motor munted remote from the knife. An annular diaphragm is mounted in the handle of the knife and is compressed by the manual inward movement of a piston by an operator. The diaphragm is connected by an air conduit which extends along the flexible drive cable to a pressure switch mounted adjacent the electric drive motor. The switch senses compression of the diaphragm and generates an electric control signal which actuates an electric clutch which couples the output shaft of the electric motor to the flexible cable for rotating the cutting blade. The piston is maintained in a diaphragm compressed position by a hand-operated lever mounted on the handle. Upon release of the lever by the operator a coil spring returns the piston to its retracted position permitting the diaphragm to expand whereupon the pressure switch senses the change in fluid or pressure within the diaphragm which signals the clutch to disengage the motor shaft from the flexible cable to stop the rotation of the cutting blade. In a modified embodiment a diaphragm pump supplies a flow of low pressure, low volume air to the handpiece. A pivotally mounted lever on the handpiece changes this air flow which is sensed by a pressure sensor which actuates the electrical clutch through a logic circuit to control the flexible drive cable. A torque selector enables the amount of torque supplied to the handpiece to be varied to complement the size of the handpiece.
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