| 摘要 |
An improved valving arrangement and actuator is provided for a power steering unit for a lift truck, and in particular for a battery powered lift truck. To the conventional implement valve is added an accumulator charging means which includes an additional valve, herein called a "blocking valve," which additional valve is downstream from the implement valve and which additional valve, when actuated, blocks the flow of fluid through the implement valve to thereby build up pressure for charging an accumulator. The blocking valve includes a blocking spool which operates against a pressure-actuated pilot plunger such that when the pressure in the accumulator reaches or exceeds a predetermined amount, the pilot plunger shifts the blocking spool to permit the fluid to again flow through the implement valve. The blocking spool is actuated by a force acting on a control member associated with the lift or tilt levers when said force is sufficient to overcome the retaining force provided by the reduced pressure in the accumulator acting on said pilot plunger.
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