GB332301A - Improved control gear for fluid operated mechanism in machine tools - Google Patents

Abstract

332,301. Link, W. April 24, 1929. Hydraulic transmission of power.-In liquid or other fluid-operated mechanism for reciprocating the slide of a machine tool the fluid is distributed by a main valve mechanically operated by the slide, and an auxiliary valve movable relatively to and controlled by the main valve. The arrangement may comprise means for diminishing the speed of the slide at the ends of its stroke. In the form shown in Figs. 1-3, a main valve body 13 co-operates with a movable ported bushing 6, and the parts are so positioned that liquid is supplied to the working cylinder 127 from a pump 1 through a passage 2, groove 3, passage 4, port 5, and passage 7, and exhaust liquid returns to the pump through a passage 8, port 9, passage 10, groove 11 and passage 12, the bushing being held in the position shown by pressure liquid supplied through a groove 18 and passages 19, 20, 23, 25. At the end of the piston stroke, the slide turns the body 13 in a clockwise direction, and liquid is supplied through passages 21, 22, 24 to turn the bushing 6 in anti-clockwise direction, so that the ports 5, 9 now register with passages 16, 15 to cause liquid to be supplied to the passage 8 and exhausted from the passage 7. When it is desired to diminish the slide speed at the ends of its strokes, the bushing 6 is provided with additional small ports 36 - - - 39, Fig. 6, and the passages 7, 8 have branches 40 - - 43. In a modified form, a slidable valve 58, Fig. 10, controls ports 70 - - - 73 so that when the valve is moved, pressure liquid acts to move a slidable member 55 in the opposite direction.