Shearing hand-piece touch sensitive to turn on remote drive motor.

摘要

A shearing hand-piece 12 is driven by a remote electric motor 14 via a flexible drive 13 housed within a conductive sleeve. An electronic control circuit is coupled to the motor and the hand-piece via the sleeve and turns the motor on to drive the hand-piece shortly after a user touches the hand-piece and turns the motor off when the user is not touching the hand-piece. The turn-on delay may be set by the control circuit. The change of capacitance of a sensor circuit as the user touches or releases the hand-piece is a convenient parameter by means of which the control can be effected