| 摘要 |
An auto cycle pump in accordance with the invention includes a housing having a reservoir for storing hydraulic fluid. A hydraulic pump in the housing provides hydraulic flow. A directional valve has neutral, advance and retract positions to respectively restrict hydraulic flow, direct hydraulic flow to an advance port and direct hydraulic flow to a retract port, the ports for hydraulic connection to the hydraulic tool, in use. Fluid conduits are provided connecting the pump and reservoir to the directional valve. A flow switch detects return flow from the directional valve to the reservoir. A pressure sensor sense hydraulic pressure from the pump. A dump valve is operatively connected to the pump for directing hydraulic flow back to the reservoir when the directional valve is in the neutral position. A control is operatively connected to the pump, the directional valve, the flow switch and the pressure sensing means for controlling operation of the auto cycle pump in automatic mode of operation. The automatic mode of operation includes activating the pump and controlling a repeatable cycle. The cycle includes operating the directional valve to the advance position or the retract position to selectively advance or retract the tool, returning the directional valve to the neutral position when the flow switch senses loss of return flow, and completing the cycle when the flow switch again senses loss of flow after flow from decompression of the fluid conduit means has stopped. The first step is configured to operate the valve alternately to the advance position and the retract position in alternate cycles, the repeatable cycle continuing until a select pressure is sensed by the pressure sensor.
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