GB445559A - Improvements relating to controlling valves for fluid systems - Google Patents

Abstract

445,559. Valves. DOWTY, G. H., 17, Lansdown Crescent, Cheltenham. Oct. 10, 1934, No. 29050. [Class 135] In control valve apparatus of the kind comprising a pair of two-valve units 7, 14, one valve 14 of each unit being opened through a mechanical interconnection such as the push rods 17 by the closing of the other valve 7 of the unit, and corresponding valves 7, 7 or 14, 14 in each unit of the pair being oppositely operated by a common mechanical operating means such as the spindle 23, all the valves are resiliently loaded non-return valves. Fig. 2 shows such a pair of units. A similar pair of units is arranged in a parallel plane in the same block 4, both pairs being shown in end elevation in Fig. 1. The block 4 has four bores each providing an upper valve chamber 5 with a seat 8 for a ball valve 7, and a lower valve chamber 6 with a seat 13 for a ball valve 14. The chambers 5, 6 each communicate alternatelv with intermediate chambers 12. The two front sets of valves 7, 14, Fig. 1, which are corresponding valves in different pairs, are depressed together by a cam 22 acting through a stiff' blade spring 19 on push rods 9. The blade spring 19 is anchored at 20 and rests on a bar 21. An operating lever 24 is secured on the spindle 23. Springs 15 return the valves 7, 14 to their open and closed positions respectively. The four rear valves are actuated in the same way, but their actuating cam 27 is at an angle to the cam 22 on the spindle 23 so that the front valves 7 are closed whilst the rear ones are open and vice versa. All the springs 15, 19 yield to allow fluid to pass the valves on overload. All four chambers 5 are in open communication by means of a bore 25, and front and rear chambers communicate in pairs by bores 28. The rear chambers 6 are closed by plugs 29 and the front ones have unions 16. In the application of the device as a reversing valve between a double-acting pump and two double-acting jacks, the pump discharges are connected to the unions 16, and the two sides of each jack to the front and rear chambers 12 on each side of the block 4 respectively. If only one jack were to be operated, the front and rear valves 7, 14 on one side of the block would be dispensed with. A modification of this kind is shown in which the push rods 9 are dispensed with and the cams 22, 27 are enclosed in a bore in the block and act on the valves 7 through two telescopically engaging cylinders pressed apart by stiff coil springs which yield to allow fluid to pass on overload.