| 摘要 |
<p>1,120,203. Valves. DOWTY HYDRAULIC UNITS Ltd. 19 Nov., 1965 [3 March, 1965], No. 9075/65. Heading F2V. A bank of slide valves is formed by six casings 12-17, Fig. 4, with interposed spring-centered and lever-actuated linearly-slidable closuremembers 24-28 in frames 18-22, the casings and frames having aligned ports 42-52 comprising a passage 53 connected to an inlet 40 and communicating with a drain connection 41 through a relief valve 54; the passage 53 opens through check valves 65-69 in the casings to elongated ports 60-64 in the closure members. The chambers (23, Fig. 3, not shown) in which the latter slide are also open to drain and the closure ports are connected thereto under the control of the end faces of the slides; each closure member embodies an unloader port 72, Fig. 6, and the casings include unloader passages 73-78 so that when all the slides are in the neutral position the inlet 40 is connected directly to drain, so by-passing the relief valve 54. Closure member 24 controls a single-acting ram and incorporates an auxiliary port and two balance ports. Closure members 25 and 27 are each provided with an extra auxiliary port and each controls a double-acting ram. Closure member 26 controls a reversible rotary motor and has recesses in place of auxiliary ports in its two upper comers; when the valve is in the neutral position both sides of the motor are connected to drain. The double-acting ram controlled by closure member 27 which has an additional or " float " position in which both sides of the ram are open to drain; one balance port only is provided consisting of a pair of opposed rectangular recesses communication via three through openings. A vertical internal passage is open to the side faces of the closure member and leads to elongated port 64. A combined relief and anti-cavitation valve is associated with each ram connection of closure member 27; the relief valve has a cup-shaped element (109, Fig. 7, not shown) loaded by a spring (110), which element seats on a hollow conical anti-cavitation valve (111) loaded by a spring (112). Any of the closure members, casings and/or frames may be repositioned or replaced and any number of valves may form the bank. Detents and microswitches may be provided with some valves and the closure members may be angularly displaceable or semi-rotatable instead of linearly movable.</p> |
