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US 4,381,695 AGranted
Hydraulically operated pump jack with holding valves and control assembly
AssigneeWink H. Kopcynski
InventorEthridge F. Ogles
Life of this patent
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AssigneeWink H. Kopcynski
InventorEthridge F. Ogles
Estimating the term…
A hydraulically operated pump jack utilizing dual hydraulically operated piston and cylinder assemblies for pivoting the beam of the pump jack and including a unique control arrangement associated with a reversing valve for controlling operation of the piston and cylinder assemblies. The control arrangement includes a hydraulically operated holding valve incorporated into each of the conduits between the reversing valve and the hydraulically operated piston and cylinder assemblies combined with a control piston and cylinder assembly for controlling the operation of the holding valves. A manually operated valve assembly is also incorporated into each conduit to enable conversion of either or both of the piston and cylinder assemblies from double acting to single acting. The control arrangement also includes a unique mechanism for operating the reversing valve automatically with this mechansim including a structure enabling manual disengagement of the automatic operating mechanism for the reversing valve with the reversing valve being capable of manual operation after such disengagement.
In a pump jack having a beam supported for pivotal movement about a generally horizontal transverse axis and means at one end of said beam for connection with a pump rod, a pair of hydraulic fluid pressure operated piston and cylinder assemblies connected to said beam for powering the beam about its pivot axis, each of said piston and cylinder assemblies being powered from a hydraulic pump having a separate conduit connected to each end of the cylinders, a reversing valve communicating the pump with the conduits, means interconnecting the reversing valve and the beam for controlling the position of the reversing valve in response to movement of the beam, and means controlling flow in each of the conduits between the reversing valve and the piston and cylinder assemblies for providing positive control of the movement of the beam throughout its cycle of movement, said flow control means including valve means in each conduit enabling flow toward the piston and cylinder assemblies and preventing return flow, and means responsive to flow in one conduit toward the piston and cylinder assembly to open the valve means in the other conduit to enable return flow.
Dependencies are inferred from the claim text.