Surgical tool

Claim 1

A surgical tool, comprising a. an electrical drive, b. a shaft connected to the drive to be rapidly reciprocated endwise with short strokes in response to drive operation, c. a tube within which the shaft extends so that the shaft tip projects from the tube, d. fastener means on the tip supporting a surgical implement to be rapidly reciprocated by the shaft, e. said drive including an electric motor having an axis, a counterweighted rotor rotated by the motor and a crank pivotally connecting the rotor to the shaft, the endwise direction of shaft reciprocation being at a substantial angle to the motor axis, and there being a casing housing the motor and drive, f. a flexible barrier sealingly connected across the clearance between the shaft and the tube at a location remote from the casing to block passage of bacteria from the tube interior to said implement, said barrier comprising a flexible annular bellows connected between said tip and the end portion of the tube, and g. the casing being cylindrical and supporting the tube to extend generally at right angles to said axis, there being a bearing in the tube mounting the shaft for linear endwise reciprocation, and the crank connections to the rotor and shaft beiNg offset from the motor axis and characterized in that the shaft stroke is less than about 0.25 inch, the tube rigidly attached to the casing and the shaft projecting into the casing interior, and the tube length externally of the casing being substantially greater than the diameter of the cylindrical casing.