Alternating rotary drive for shaft - uses jack between crank and pin joint common to fixed fulcrum pivot arm and sliding pivot arm

摘要

The jack (C) effects the automatic reciprocal half turn rotation of a shaft, to reverse tools such as ploughshares. One end of the jack is pinned to a shaft crank (B) of which the reciprocal movements are limited by two stops (1,1'), the other being pinned to an end of an arm (E) secured by an axle pin (3) in a slot hole. The axle (4) securing the arm to the jack also locates the ends of a pair of pin-jointed connecting rods (D) extending to a fixed fulcrum (2), locating the rods with a degree of float. The rod causes reciprocal displacements of the jack from one side to the other of a vertical plane, the strap obviating jamming whilst permitting the centre of gravity of the tools to pass through the upper dead point for jack inversion.