摘要 |
A control valve for a selectively engageable friction device has two flow rates for controlling piston movement during the application of the friction device. The valve includes a spring-loaded valve capsule slidably disposed in a stepped diameter bore between a feed passage and a control passage. When the fluid pressure in the feed passage exceeds the fluid pressure in the control passage by a predetermined amount, the capsule is moved in the bore against the spring so that, the outer cylindrical surface of the capsule and the largest portion of the bore cooperate to form an orifice which permits a high flow rate resulting in a rapid fill operation of the piston cylinder of the friction device. The pressure in the piston cylinder, sensed in the control passage, and the spring move the capsule into the next largest diameter portion of the bore to provide a reduced flow during the final pressurization of the piston cylinder of the friction device. A check valve in the capsule permits rapid exhausting of the friction device when the feed passage is exhausted.
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