GB1057707A - Hydraulic regulating system and apparatus - Google Patents

Abstract

1,057,707. Feeding webs. M. TAKEDA. April 1, 1964 [April 1, 1963], No. 13520/64. Heading B6B. [Also in Division G3] A hydraulic apparatus for controlling the position of a member such as the recentring of a moving sheet of material in response to lateral deviation comprises a jet nozzle 51 which cooperates with receiving passages 56, 57 leading to chambers 62, 63 at opposite ends of a spool valve 71. The valve 71 controls the supply and exhaust of fluid to the opposite sides of a piston 102 and the valve also has lands 81, 84 which co-operate with bleed passages 86, 87 of smaller diameter than the passages 56, 57. The jet 51 is moved by solenoids 41, 42 which are energized in response to lateral deviations of the sheet 107 which closes switches 108 or 109. With the valve 71 in its centred position, the lands 81, 84 throttle the passages 86, 87 to an equal extent. If the solenoid 41, say, is energized, the jet 51 moves against stop 46 and directs more fluid into passage 56 which causes valve 71 to move to the right against stop 76. This movement of the valve closes passage 87 and fully opens passage 86. However, since passage 86 is smaller than passage 56, part of the fluid returns out of the passage 56 and acts on the side of the conical jet surface 52 so that when the solenoid is deenergized, the fluid force acts to move the jet back towards a central position which causes flow into the passage 57 to recentre valve 71. In the central position, the forces acting on the conical surface are equal.