GB1116872A - Selector valves - Google Patents

Abstract

1,116,872. Valves. ELECTRO-HYDRAULICS Ltd. 12 May, 1966 [6 May, 1965], No. 19155/65. Heading F2V. A selector valve comprises a valve body 2 having opposed cylindrical bores 4, 5, a valve plunger 23 with cylindrical end portions 21, 22 slidable in the bores between mechanical stops 15, 33, a flat ported plate 40 co-operating with the valve body, a valve member 49 of resilient material arranged to be moved by the valve plunger to place ports in the plate selectively in communication with one another, spring means 50 to urge the member 49 on to the plate, means to supply fluid pressure to the body to urge the member 49 into sealing engagement with the plate and a further plunger 27 slidable in a cylinder 25, the plunger and cylinder being responsive to a pilot pressure to move the valve plunger in one direction. Pilot pressure applied to port 42 or port 43 shifts the plunger from one end position to the other or applied simultaneously to both ports holds the plunger in a central position when a plunger and cylinder, such as that shown at 25, 27, is provided at both ends of the valve body. A filter element 37a is provided in each cylinder and in a modified construction the mechanical stop 33 at each end of the body extends through the stem of the piston and has flats to provide fluid communication with the spaces subjected to pilot pressure. In a further modification, each end of the plunger has a bore to receive a piston cooperating with a stop in the end wall of the valve body and the two bores are connected by an axial and a radial passage in the plunger with the space 6. Slotted lugs 35 are provided to receive the fulcrum pin of a lever when the plunger is to be actuated manually.