Abstract: A downhole bladder pump for pumping ligher-than-water liquids. The pump includes an outer tube closed at its bottom and top, but having slots adjacent its upper end to admit the liquid to be pumped. Positioned concentrically within the outer tube is a cylindrical bladder chamber. A cylindrical bladder is mounted within the bladder chamber and registers with the internal surface of such chamber. A cyclically-operated pneumatic control system periodically delivers pressurized air to the space between the bladder and the bladder chamber to collapse the bladder and pump liquid which has flowed into the bladder. At other times during the cycle, the control system draws the bladder outwardly against the internal surface of the bladder housing by the application of vacuum. The liquid to be pumped is then forced into the bladder through a check valve subassembly positioned in the lower end of the bladder housing.
Abstract: This invention relates to an automatic hydraulic reversing valve for a double-action working cylinder. The purpose of the invention is to employ valves of this type without the requirement of an expensive servo-control mechanism, but nevertheless having a high operating reliability. The present invention, in avoiding the use of servo-control devices, utilizes a separate thrust piston which urges a control piston into a startup position, at which position the hydraulic medium is directed to the thrust piston end of the control piston, a blocking slide valve also being employed in the system and being mounted in the control piston for connecting the thrust piston end of the control piston to a tank or for blocking the connection to the tank.
Abstract: A starting mechanism for a reciprocating piston pneumatic hammer provides a passageway coupling a pneumatic piston subchamber to an exit port to exhaust pressurized pneumatic fluid from the subchamber during a start-up period. A pneumatic valve is provided to open the passageway as the hammer is started so as to create a pressure differential in the coupled piston subchamber, and thus prevent the piston from centering. The valve closes the passageway after the piston reciprocation has begun.
Abstract: An oscillator actuated hydraulic impulse of the type including a spool valve actuated by an alternating signal from an oscillator to switch the hydraulic pressure in a double acting cylinder in order to cause reciprocating motion of a piston which strikes a boring tool. The hydraulic impulse device further includes a means for controlling the transition from the impulse stroke to the return stroke of the piston. In some embodiments, the hydraulic impulse device may further include a means for varying the duration of the impulse stroke and the return stroke of the piston.
October 30, 1980
Date of Patent:
August 3, 1982
Mitsui Engineering and Shipbuilding Co., Ltd.
Abstract: A vapor engine including a cylinder in which a piston reciprocates and having an inlet valve in the cylinder head which is driven from its seat by the piston as it approaches the cylinder head. The time at which the valve is driven from its seat does not change relative to the top dead center position of the piston. The travel of the valve body is ballistic and the valve remains open for a time determined by a combination of the piston velocity at the initial contact, the distance the valve travels before hitting a stop from which it rebounds elastically toward its seat, the pressure drop across the valve and the mass of the valve. The exhaust valve of the engine may be either internal and actuated by mechanical forces or external, in which case it is actuated by pressure forces. In one embodiment of the invention the stop from which the valve rebounds may be adjustably positioned manually or automatically to control the period of time during which the intake valve is open.