GB552324A - A new or improved automatic control valve for air and other fluids - Google Patents

Abstract

552,324. Fluid-actuated valves. ALLEY & MACLELLAN, Ltd., and DAVIES, W. D. Oct. 10, 1941, No. 13116. [Class 135] A valve device opened under hand control and adapted to close automatically if the pressure of the fluid drops below a predetermined value and then remaining closed until the hand control is operated has the main valve actuated by a piston exposed on both faces to inlet pressure when the valve is closed, one face being connected to atmosphere through an auxiliary valve to open the main valve. In the form shown in the Figure a lift valve member 16 with a fibre facing 15 to co-operate with a removable seating 14 is rotatably connected to a spindle 17 fixed to a piston 20. This piston which is loaded by a spring 43 works in a liner 21a and is formed with a sealing face 24 adapted, when the valve is open, to engage a fibre washer 23 beneath a cover 22 or a ground face on the cover. The auxiliary valve 30 actuated by a push 39 against the action of a spring is adapted, in the position shown, to connect the space above the piston to the inlet by way of passages 28, 42 in the casing and an axial passage 33, port 34 and annular groove 35 in the valve member. When the knob is pressed this connection is interrupted and the space above the piston connected to atmosphere by way of passages 28 and 33 port 36 and flats or grooves 38 in the spindle. As the piston moves to its upper position it obturates the passage 28 and an extension 27 on the spindle 17 lifts a spring- loaded vent valve 26 to prevent the accumulation of pressure above the piston due to leakage past the piston which accumulation would cause premature closing of the valve. A hinged cover 40 prevents accidental operation of the auxiliary valve. In a modification the lift valve is replaced by a sluice valve.