GB466218A - Improvements in and relating to hydraulic controlling means for machine tools - Google Patents

Abstract

466,218. Hydraulic transmission of power. WOTAN-UND ZIMMERMANNWERKE AKT.-GES. Nov. 29, 1935, No. 33208. Convention date, Dec. 5, 1934. [Class 69 (ii)] [Also in Group XXII] In hydraulically operated machine tools, especially planing machines, the liquid expelled from the working cylinder is conducted to an auxiliary valve by which it is supplied alternately to opposite ends of the main control valve for effecting reversal. In the form shown in Fig. 2, the main valve 2 is positioned for causing the working piston 5 to move to the left, the liquid expelled passing through pipes 4, 6, 7 to the auxiliary valve 8, and thence by pipes 9, 10 to exhaust. When the valve 8 is reversed, the liquid passes through a pipe 12 and reverses the main valve, finally passing to exhaust through a pipe 15. To avoid any interruption in the supply of liquid to the pipe 7, the main valve 2 has a central enlargement slightly shorter than a recess in its casing, so that when it is in its central position, liquid may pass from the pump 1 to the pipe 7. A cylinder and piston 16 for effecting a subsidiary movement such as a cross-feed may be inserted in the pipes 10, 15. In a modification, the cylinder and piston 16 may be placed, as shown in Fig. 3, so that the subsidiary movement is effected before the reversal of the valve 2.