GB193852A - Improvements in valves - Google Patents

Abstract

193,852. Larner, C. W. Feb. 25, 1922, [Convention date]. Valves controlled by pilot valves. - A fluidactuated valve of the kind comprising a casing containing an internal cylinder closed at one end except for a small leakage port and provided with a plunger having a tapered nose adapted to seat against a contracted part of the casing has the nose of the plunger formed with a chamber having auxiliary valve -controlled communication with the interior of the cylinder and having a discharge connection to the conduit at a point where substantially constant-flow conditions are maintained. The chamber 17 is connected to the outlet conduit by a series of openings 18 in the inclined face 12 of the plunger arranged so as to be either normal or inclined to the direction of flow over the face. The auxiliary valve 20 is adapted to be moved into or out of engagement with a seat 15 in the side 16 of the chamber 17 by a hand-operated pinion 24 engaging a rack 23 on the spindle 21 which is guided by a boss 22. The Specification as open to inspection under Sect. 91 (3) (a) comprises also a modification in which the auxiliary valve-member is provided with a cylindrical extension adapted to pass into the valve seat to provide a certain amount of lap or free movement between the pilot valve and the plunger. The auxiliary valve spindle may have a piston adapted to work in a dashpot cylinder supported by the plunger or the plunger itself may be stepped to form a dashpot chamber in which case a dirt-trap and blow-off connection is provided. And also modifications are described in which the auxiliary valve spindle is made hollow and either slides through the closed end of the cylinder or telescopes on a pipe secured thereto and is provided with a series of ports near the valve head so that the movement of the auxiliary valve controls the inlet to as well as the exhaust from the chamber 17. The auxiliary valve may be designed to close one conduit before the other is opened or both conduits may be open together. A plug may be fixed to the cylinder so as to reduce the capacity of the actuating chamber. The chamber 17 and openings 18 may be dispensed with, the pilot valve then controlling an opening communicating directly with the fluid conduit. This subjectmatter does not appear in the Specification as accepted.