GB1351268A - Reciprocable hydraulic system - Google Patents

Abstract

1351268 Hydraulic control circuits INTERNATIONAL BUSINESS MACHINES CORP 25 Oct 1972 [22 Dec 1971] 49106/72 Heading F1P [Also in Divison B2] In the arrangement shown in Fig. 1, fluid under pressure is supplied by a pump 16 and a solenoid valve 18 alternately to the undersides of pistons 11, 13, the spaces above the pistons being connected by a line 22, so that as one piston moves up the other is moved down and the pistons are synchronized by adjusting the volume of fluid in the line 22 under the control of means which sense the position of the pistons in the cylinders. The valve 18 is operated by a switch 36 which is magnetically operated by magnetic pieces 38, 40 which reciprocate with the piston 11. Excess fluid is fed back to a reservoir 20 through a valve 24 which is opened when the pistons are not sychronized. The piston strokes are adjustable by altering the positon of the pieces 38, 40, so synchronization is checked at the mid-point of travel by magnetic switches 26, 30. Valve 24 opens when its solenoid is energized. One of switches 26, 30 is normally open and the other closed and change over occurs at the mid-point of piston travel. Any lack of synchronization causes both switches to remain closed until sychronism is restored by fluid passing out of the line 22. Fig. 6 shows an arrangement in which oil may be added to the line 22 by a valve 27 which is controlled by a second pair of contacts, one in each of switches 26, 30. When both these contacts are closed, due to lack of sychronization, fluid is added to line 22 through the valve 27. In a further modification Figs. 8, 9, (not shown), exess fluid is corrected on the upstroke of piston 11 and lack of fluid on the downstroke of piston 11. An electrostatic spray painting disc may be connected to a motor 14.