GB980932A - Improvements in or relating to fluid tight joints, particularly for sectional control valves - Google Patents

Abstract

980,932. Valves. HYDRAULIC UNIT SPECIALTIES CO. June 5, 1962 [March 30 1962], No. 21769/62. Heading F2V. A number of hydraulic control valves 7, Fig. 3, are sandwiched between inlet and exhaust manifolds 5, 6 containing chambers 10, 12, respectively. Each valve 7 has a slidable spoolclosure member and is shown as being of the parallel circuit double-acting type although other types may be employed. Each spool 16, Fig. 2, when moved from the neutral position shown controls communication of one motor port 18 to the supply chamber 10, Fig. 3, and the other motor port 18, Fig. 2, to the exhaust chamber 12, Fig. 3. Each valve 7, Fig. 2, has a supply header 19 which opens via a check valve 31 to branches 32 leading to the spool bore into which also opens branches 34 from an exhaust header 20. The supply header 19, Fig. 3, passes through each valve 7 and leads to the chamber 10; the exhaust header 20, which is similarly arranged but on the other side of the spool bores, connects with the chamber 12 and includes a duct 25 opening to the chamber 10 via a relief valve 26. The chamber 10, 12 by a zig-zag passage 28 that passes through the centre of each spool bore; if the valves 7 are of the seriesparallel type the branches 32 are supplied from the passage 28 instead of the header 19 in which case the latter is connected to the branches by a lateral branch that houses the check valve 31. Each adjacent face of the valves and manifolds are machined flat or machined areas such as pads 36, 38, Fig. 4, are formed. Leakage between each interface is prevented by an " O "-ring 40 in a groove 41 which defines the outer limit of a shallow depression 42 around an island 43 with a part of the flat face 38 thereon; the island 43 encloses the header 19, 20 and the through passage 28 so that any leakage of fluid from the battery to the header 19 flows via the depression 42 to the exhaust header 20.