948,172. Valves. INTERNATIONAL BASIC ECONOMY CORPORATION. June 30, 1961, No. 23700/61. Heading F2V. A fluid control valve comprises a valve body 11, Fig. 1, having a main valve chamber 13 in which a main valve member 40 is reciprocable between two positions providing fluid flow between inlet and outlet ports 15 to 18 in the chamber 13, a second valve member 58 longitudinally spaced from the main valve member and reciprocable to provide fluid flow to control the latter and sleeve members 20, 21, 22 slidably removable from the chamber 13. Inlet pressure in port 15 holds the main valve member in the position shown until the second valve member 58 is retracted against a spring 63 by energization of a solenoid 53. Inlet fluid now flows through passages 11, 48 a valve seat 45 and passages 223 to act on a piston 41 and move the valve member 40 to its second position. The valve member 58 is fluted to permit fluid above the piston 41 to escape through a valve seat 59 and passages 61, 75 to atmosphere when the valve member 40 is returned to its first position. The passages 75 are formed in a rotary valve 72 which may be rotated to place the passage 61 in communication with a passage 78 and allow inlet fluid to act on the piston 41 with the solenoid de-energized. Inserts of rubber are provided in the valve member 58 to co-operate with the seats 45, 59 while the valve member 40 is fitted with " O " rings 86, 87 and 90, Fig. 9, separated by retainers 88, 89 having radial grooves (not shown) for the escape of fluid trapped beneath the centre ring. A cap 12 and a base 10 are connected to the body 11 by screws extending through aligned apertures in all three parts and threaded into the base. Slots form the apertures in the cap so that the latter may be freed by partial rotation once the screws have been loosened while plug and socket connections are provided in the wiring to the solenoid where it passes between the separate parts 10, 11, 12. Fig. 10 shows a second costruction in which fluid from an inlet passage 15a acts through a port 29a on the upper surface of a land at the lower end of the valve member 40a and through a port 28a on the lower side of a piston 41a of larger diameter than the land. When the valve member 58a is lifted against spring pressure by energization of a solenoid 53a, fluid from the inlet flows through passages 92, 46a and the valve seat 45a into passages 223a communicating with the space over the piston so that the valve member 40a is moved to its lower position. The retainers on each valve head 42a, 43a form a space which is tapered in a radially outward direction to prevent the central " O " ring from being squeezed out between them. To enable the valve to operate at high speed, a short fluid path of large cross-section is provided between the inlet passage 15a and the space above piston 41a. A valve 101, which may be displaced by hand or by a screwdriver against spring and fluid pressure to permit fluid to flow from inlet passage 15a to the space over the piston 41a, may be held in its actuated position by rotation of the valve stem to move a transverse pin angularly out of alignment with slots 106 in the cap 12a. If the valve 40a is an air-actuated hydraulic-valve, a seal is inserted in the groove 94 and the space beneath the valve is vented through the valve 101. Passages for fluid and electric wiring in the base may be arranged to connect automatically with those in the bases of other valves when a number of valves are bolted together in one unit. In Figs. 17 and 18, the valve 58d has a toggle mechanism to hold it in the position to which it has been moved by momentary energization of one of a pair of solenoids 53d. This mechanism comprises a lever 149 which is pivoted at 150 and has two projections 151 to engage a recess 147 in the valve and a third projection 154 to engage one end of a helical spring 152. An eccentric projection 158 on a rotatable spindle 160 permits the valve 58d to be manually actuated and is urged to a neutral position by a spring-loaded plunger 160. Specifications 948,173 and 948,174 are referred to.