| 摘要 |
1424574 Valves SPERRY RAND CORP 16 April 1973 [ 18 April 1972] 18206/73 Heading F2V A bankable valve comprises a generally rectangular body 20, Fig. 2, of a thickness, from a spool bore 22 to its periphery, about twice the spool diameter or a little greater; a supply port 26 traversing the body thickness and lying mid-way between the ends of the body; a pair of holes to receive clamping bolts 16 traversing the body thickness and spaced from the supply port towards the end of the body; a pair of exhaust ports 28 traversing the body thickness and spaced from said holes towards the ends of the body; the supply port 26, the bolt receiving holes 16, and the exhaust ports 28 lying generally along a line parallel to and at one side of the spool bore; passages 30 connecting the supply and exhaust ports with the spool bore; passages 44, 46 constituting service ports; and a spool 24; the body having substantially equal quantities of metal on each side of the spool bore whereby distortion of the bore due to unequal expansion of the metal caused by aging or by temperature rise is minimized. The valve also includes an anticavitation valve 50; a relief valve 48; a check valve 36 to prevent dropping of a load in the event another valve in the bank should not be maintaining adequate pressure in the connecting supply port 26; a pair of sensing passages 38 leading to a load compensating valve 32; and a check valve 40 with a through-port 42 extending from section to section of the bank. The spool 24 contains counterbalance valves 52 which control holes 54, 56, the one or the other valve being opened by supply pressure in a passage 58 when the spool is shifted to the right or the left. A supply and return section 10, Fig. 3, for connection to a bank of the valves, comprises a supply passage 62 which connects with the supply port 26; a return passage 64 which connects with exhaust passages 28; an unloading valve 68, controlling communication between passages 62 and 64, provided with a restricted passage 73; and a passage 70 for conveying fluid from a source connectable at 74. The unloading valve 68 may be replaced by a balanced relief valve (75), Fig. 3 (not shown). |
