| 摘要 |
<p>1,135,308. Valves; fluid pressure brakes. POCLAIN. 1 May, 1967 [13 May, 1966], No. 20004/67. Headings F2F and F2V. [Also in Division F1] A spool valve for supplying and relieving hydraulic pressure to and from a single-acting cylinder e.g., the brake ram A of a winch winder B at the same time as hydraulic pressure is supplied to and relieved from one or other of two lines leading from a distributor C to a reversible motor driving the winch comprises a chamber 19 continuously connected by a duct 3 to the ram cylinder A and also connected either to a vent chamber 20 of the valve or to a pressure chamber 9 thereof according to whether the spool is held by a spring 22 in the position shown or is urged to the left by fluid pressure in either of the motor supply lines being admitted through ducts 5, 6 to the ends of pilot pistons 10, 17; the chamber 9 being pressurized from said motor supply lines through ducts 11, 14 and non- return valves 12, 15. In operation and to wind in the winch, distributor C is set to pressurize the motor supply line connected to valve duct 5 resulting in piston 10 and hence valve spool 2 being displaced against the spring 22, and pressure in chamber 9 is transmitted through chamber 19 and duct 3 to lift the ram A and remove the brake.</p> |
