GB705669A - Improvements relating to valve systems for the control of fluid pressure - Google Patents

Abstract

705,669. Fluid-actuated valves. FERRANTI, Ltd. Jan. 3, 1952 [Dec. 27, 1950], No. 31343/50. Class 135 A valve system in which delivery fluid pressure is controlled by valves in the fluid supply and exhaust, comprises a vessel 11 having an axial supply passage 19 through a piston 13 traversing a cylinder 10 in response to delivery pressure at 18, and which is opened by a supply valve 50 when the piston moves away from the supply side of the valve, and an exhaust valve 51 which closes the exhaust 15 when the piston moves in the same direction, a leaky second piston 31 linked to the first and traversing a second cylinder 35, connected at one end to the supply at 14 and having the pressure therein regulated by a device controlling an orifice 33 at the other end which opens to a low pressure region. The pressure in cylinder 35 is set by adjusting a screw carried, rubber pad 36, a needle valve or the edge of a rotary cam controlling the orifice. Should the delivery pressure decrease below that in cylinder 35, the piston moves to the right seating the exhaust and unseating the supply valve which are connected by the rod 52. On a rise in delivery pressure, the reverse happens. In a modification, a side exhaust port is closed by the piston 13 itself, while the supply valve is a ball carried by the hollow rod connecting the pistons and which is unseated by an adjustably screwed rod carried in the end of the cylinder and projecting into the supply port.