GB231416A - Improvements in hydraulic drive for broaching machines and the like - Google Patents

Abstract

231,416. Lapointe Co., J. N., (Assignees of West, D. H.). March 26, 1924, [Convention date]. Broaching.-An hydraulic drive for the reciprocating members of broaching machines constructed so that the return stroke is more rapid than the working stroke comprises a pump 20, which delivers liquid to a chamber 19 for causing the working stroke of a member 12 through a piston 18 and piston-rod 14, and delivers liquid through a stationary pipe 23 to the interior 21 of the piston rod for causing the return stroke. During the working stroke, liquid from the chamber 21 passes to the pump through pipes 26, 25 and liquid from the. chamber 23 passes to a reservoir 24 and also to the pump through a pipe 46, valve 47, and pipe 25. During the return stroke, liquid moves as indicated by the arrows. The pump out-put is reversible in direction, being controlled manually by a lever 52 or automatically through lugs 53, 54, 55, its controlling means being preferably connected to the rod 48 of the valve 47. In a modification, the pump may deliver in one direction only, means being then provided for reversing the connections to the pump. The reservoir 24 is open to permit escape of air, and the chamber 19 is connected to it by a conduit having a valve 54, which is opened by a weak spring between the strokes. Relief valves 27, 37 are provided, a pan 30 receiving liquid from them and from a pump leakage drain 29. The pan 30 and reservoir 24 may be combined in one receptacle set either at the top or bottom of the apparatus, and air-venting means may be provided.