GB892591A - Improvements in or relating to hydro-pneumatic actuating devices - Google Patents

Abstract

892,591. Hydraulic intensifiers. NEWTON & BENNETT Ltd. Feb. 29, 1960 [Feb. 28, 1959], No. 7063/59. Class 69 (2). [Also in Group XXII] An hydro-pneumatic intensifier wherein relatively low pneumatic pressure is converted into relatively higher hydraulic pressure comprises a control valve 35 on the pneumatic side having an actuating lever 42, a non-return valve 14 on the hydraulic side, and means 25 for neutralizing the non-return valve. The non-return valve consists of a ball 32 which is spring-urged against a seating 30 and permits hydraulic fluid pressurized in a cylinder 10 to pass to a line 17 connected to a mechanism to be actuated, such as an hydraulic clamp or chuck in a machine tool. The hydraulic fluid in the cylinder is pressurized by pneumatic pressure acting on a diaphragm 12 moving a piston 11 into the cylinder, the pneumatic pressure being supplied from the control valve 35 which is actuated by the lever 42 movable to one position wherein it connects a supply line 38 to a line 37 leading to the diaphragm chamber and a line 36 to exhaust, and to an alternative position wherein it connects the chamber to exhaust and the supply line to the line 36 which leads to a piston 23 movable by the pneumatic pressure against a spring to cause a rod 25 to lift the ball 32 from its seating and release the pressure in the line 17. In an alternative embodiment, the diaphragm chamber is replaced by a piston and cylinder, the piston being connected to the piston in the hydraulic cylinder.