GB198666A - Improvements in or relating to shutting off devices and valves - Google Patents

Abstract

198,666. H³bner & Mayer, and Roschanek, O. May 31, 1922, [Convention date]. Valves closing with rush of fluid.-An automatically closing valve is arranged so that when the valve is moved towards its seat, consequent on a rush of fluid, fluid is admitted to a cylinder to retard the closing movement and so prevent hammering. In the form shown in Fig. 2, the main valve member 1 is formed integrally with a subsidiary valve face 2 adapted when the main valve moves towards its seat to allow pressure from the main conduit to act on a braking piston 6. Part of the pressure so admitted escapes to atmosphere through a valve-controlled passage 11 and the excess passes between the piston and the cylinder to an annular chamber in a member 9 and thence to the actuating chamber of a safety valve or other apparatus. The escape passage 11 may be formed in the casing and a hand-actuating lever may be fitted. The subsidiary valve and piston may be connected to a lever carrying the valve or an oscillating vane for actuating the valve. In order to give a progressive braking action, the piston may be normally clear of the cylinder, may co-operate with a tapered chamber, or may be stepped to work in a stepped chamber. In the form shown in Fig. 10, the braking cylinder communicates with the fluid conduit through a restricted valve-controlled passage 44 and through larger grooves 5 in the spindle which are closed as the main valve moves towards its seat. In the form shown in Fig. 7, the main valve has a skirt adapted to cooperate with a boss 26 to reduce the supply to the braking chamber as the valve rises. The main valve can be closed by admitting fluid pressure through a control valve 31 to the space below a spring-loaded piston 29, which space is provided with a valve-controlled leak 33. A second piston 35 is arranged below the piston 29 working in a chamber provided with an adjustable leak 37 and wiper connected by a pipe 36 with the other automatic valves on the system so that they all may be closed simultaneously. The Specification as open to inspection under Sect. 91 (3) (a) describes also combined stop and check valves fitted with rotary valve or reciprocating piston dashpots. This subject-matter does not appear in the Specification as accepted.