Abstract: A hydraulic power and control system which includes a pump which is mounted n a sealed housing. The pump is mounted in the sealed housing along with a pilot operated power valve. The pump has an inlet within the housing for intaking oil therein and is connected to the pilot operated power valve for operating components in a functional system, such as a submersible docking apparatus. The pilot operated power valve discharges oil into the sealed housing and is connected to a control valve which is located exterior of the housing. The control valve will pilot operate the power valve and discharges oil within the sealed housing. The control valve may be mounted within a pressure casing which receives a reduced oil pressure from the pump within the sealed housing. The sealed housing may be pressure compensated to ambient so that the pressure casing is maintained at a specific pressure level above ambient.

Abstract: A pump jack for pumping oil and like wells having a polish rod extending vertically out of a well casing is provided including a frame adapted to fit over said well, a hydraulic cylinder depending from said frame generally coaxially of said polish rod, a piston movable in said cylinder and having an end engaging said polish rod, a source of high pressure fluid connected to said cylinder for raising said piston in the cylinder, dump means on said frame simultaneously discharging the raising fluid from said cylinder and by-passing fluid from said source of high pressure fluid to said source of fluid, means on said piston selectively actuating said dump valve from a first position where all fluid from the source of high pressure fluid is delivered to one side of the cylinder for raising the piston to a second position where all fluid from the source and from said one side of the piston is simultaneously returned to the source and to the other side of the cylinder whereby the piston and polish rod are successivel

Abstract: A hydraulic fluid storage tank for an industrial vehicle. A small surge tank (44) is mounted on top of a main tank (10) and communicates with the main tank via a drain back hole (49) formed in the top of the main tank. A first breather tube (46), having one end opening within the surge tank, extends directly into the main tank. A second breather tube (48), having one end opening within the surge tank, enters the main tank through the drain back hole, extends along the top of the tank, and opens into the tank at a point substantially rearward of the first vent tube. If, due to movement of the vehicle, one of the breather tubes becomes filled with oil, the other will still function. Oil which momentarily floods one of the breather tubes enters the surge tank and drains back to the main tank via the drain back hole.

Abstract: A readily portable hydraulic power source for supplying hydraulic fluid pressure to emergency hydraulic tools is foot-operated such that the operator's hands are left free to use the hydraulic tools and both the tools and power source may be operated by a single person. The power source includes a generally planar base member, a hydraulic pump fixedly mounted at one end of the base member, a foot-engaging planar member in generally overlying relation to the base member, a hinge connecting ends of the base member and the planar member for movement of the planar member relative to the base, and a resilient spring between the base and planar members to urge the members pivotally apart upon release of pressure from the operator's foot. The operator's foot is retained by straps and a heel retaining portion attached to the planar member, with the heel portion having an arm operatively connected to a hydraulic piston of the pump.

Abstract: Disclosed are methods and apparatus for controlling the flow of hydraulic fluid to and from a work cylinder. The disclosed system includes a reversible variable displacement pump interconnected between a work cylinder and a selector valve which may connect the pump with any of a plurality of fluid reservoirs. The fluid reservoirs contain hydraulic fluid at variable pressures so that the pressure at the work cylinder may be raised to pressures well above the pressure differential capacity of the pump at maximum flow rate by selectively increasing the pressure on the reservoir side of the pump. The system includes means for controlling the pressure at each port of the pump so that the pressue on the output port is always greater than the pressure on the input port regardless of the direction of flow through the pump and regardless of pressures at other points in the system.

Abstract: The specification discloses a hydraulic pressure operated emergency hand tool of the type in which manual pressure exerted on an all position small-area pump piston creates a hydraulic pressure which is communicated to a power cylinder for activating a plural jaw tool member, such as a pair of cutter blades. The jaw members are pivoted together intermediate their ends and one end of each is pivotally connected one to the power cylinder opposite the free end of the piston and the other to the free end of the piston. A release valve provides instant return displacement of hydraulic medium via a by-pass communication from the cylinder to the reservoir to relieve the activating pressure on the cutter blade and restore it promptly to normal position. Interchangeable tool members are provided.

Abstract: An air pressurizing system including a double acting pneumatic cylinder operatively connected to hydraulic actuated equipment for operation thereby in response to movement thereof to pressurize a hydraulic fluid tank or reservoir and control the air pressure coupled into the hydraulic fluid tank.

Abstract: A liquid manure spreading apparatus having a tank and a pump selectively operable to evacuate air from within the tank or supply air to the tank. A safety shut off valve located in the tank having a ball and an elongated float confined in a cage is operable to block the evacuation of air from the tank when the tank is full of liquid manure. A control valve mounted on the pump has a single spool selectively moveable with a handle to an air evacuating position and an air supplying position. A single air line is connected to the valve and tank.

Abstract: Means for controlling the decompression of a pressure chamber, such as an actuating pressure chamber of mine cage holding apparatus, including an outlet passage adapted to communicate with the interior of the pressure chamber; a valve seat associated with the outlet passage; a movable valve member movable into and out of engagement with the seat, the valve member or a part movable therewith being adapted to obstruct the outlet passage during at least part of the travel of the valve member away from the seat with a resistance to the release of pressure from the pressure chamber which decreases with increasing displacement from the seat; a control fluid chamber; a control piston movable in the control chamber and adapted to urge the valve member towards engagement with its seat under the influence of fluid pressure in the control chamber; and a vent from the control chamber through which fluid can escape.

Abstract: A combined brake and steering system for a vehicle having hydraulic braking and hydraulic steering. A single pump is utilized to supply both the brakes and steering. Two priority valves are arranged to assure that the brakes take precedence and receive an approximately constant flow of hydraulic fluid subject to a predetermined maximum pressure. The steering mechanism also normally receives a constant flow, subject to a different maximum pressure. The fluid from the steering mechanism is recirculated through a reservoir back to the pump. The fluid from the brakes is recirculated to the pump without going through the reservoir.

Abstract: A closed rigid tank stores oil or other liquid for use in operating hydraulic jacks or other fluid-driven devices. A flexible bladder within the tank is coupled to a source of compressed air and to an air pressure regulator in order to maintain a constant positive pressure in the tank as the bladder expands and contracts in response to the withdrawal and return of oil. The sealed regulated pressure tank may be smaller, lighter and less costly than the tank structures heretofore used in hydraulic systems and the construction is more adaptable to variations in tank shape and location relative to other system components. Fluid lines which connect the tank and fluid pump may be smaller and the total volume of oil required for the hydraulic system may be reduced.

Abstract: A compressed air generating device for forklift trucks in which a main pipeline connected to the end of the lift cylinder air chamber branches into a high-pressure air pipe and a return pipe, selectively communicating with the main pipeline through a switching valve means. With the main pipeline switched to communication with the main pipeline high-pressure air pipe, during the descending phase of the piston, air is sucked through an air suction pipe attached to the main pipeline into the lift cylinder air chamber, and during the rising phase of the piston, the air in the air chamber is compressed and is sent into an air tank as compressed air.

Abstract: An air extracting system for a hydraulic steering apparatus which has a pump, a reservoir and a piston-cylinder mechanism which is geared to the steering gear. A two-position changeover valve is positioned in the hydraulic circuit between the pump and the piston cylinder mechanism, which in one position connects them in a closed circuit and in the other position connects the return portion of the hydraulic circuit to the reservoir. The piston has a bore therethrough with a two way check valve therein with a check valve opening element which opens the check valve at the end of the stroke of the piston. When the changeover valve is positioned to connect the return of the hydraulic circuit to the reservoir, when the piston reaches the end of its stroke, the check valve is opened to cause air in the system to pass through the check valve and through the changeover valve to the reservoir.