GB452165A - Improvements relating to hydraulically operated machine tools - Google Patents

Abstract

452,165. Hydraulic transmission of power. ARCHDALE & CO., Ltd., J., Ledsam Street, Birmingham, and WEGERDT, F., 2, Kyffhõuserstrasse, Chemnitz, Germany. April 26, 1935, No. 12526. [Class 69 (ii)] In hydraulically operated machine tools comprising a main cylinder supplied by a variable delivery pump, an auxiliary pump supplies or draws from, at a regular rate, which may be adjusted, an auxiliary cylinder associated with the reciprocatory part of the machine, the variations of pressure in said auxiliary circuit being utilized to regulate the output of the main pump. The invention, as applied to the machine described in Specification 452,166, comprises a main cylinder d, movable on a fixed piston e, and supplied from a main pump 1, which may be constructed as described in Specification 424,609, [Group XXVIII]. The reciprocating work table a carries an auxiliary cylinder 20 movable on a fixed piston 20a and connected to the reversible auxiliary pump 18. The auxiliary pump pressure acts on a valve 22 against a spring 22a, so that when the table speed varies, the valve 22 is moved to allow liquid from the auxiliary pump or another source to pass from a pipe 23 and reduce or increase the output of the pump 1 by action on a plunger 27 or 28. The pump 18 is reversed by liquid acting under pilot valve control on a plunger 32a or 33a, and its output may be varied by liquid acting on a plunger 34. When the table a is rapidly traversed, the pump 1 is given its maximum output by liquid acting on a plunger 41, and a valve 42 is actuated to place the pump 18 and cylinder 20 into communication with a liquid tank.