Abstract: A housing for a downhole tool, having a fluid vent assembly comprising a port passing through the wall of the housing to transmit fluid through the port when the port is open, a sealing device to seal the port, and a cutting device to disrupt the sealing device and permit transmission of fluid through the port. The cutting device is driven axially through the sealing device without relative rotation between the two. The cutting device has an asymmetric blade to cut a coupon from the sealing device by a gradual and progressive disruption of the closure, typically cutting through only a portion the closure device, so that the coupon cut from the closure device remains attached to the closure device when the closure device is ruptured to open the seal. Typically the downhole tool comprises a downhole pump, and the housing comprises the shroud of the pump.

Abstract: A floatless pneumatic pump having an elongated housing including a sealable fluid entry aperture and a pipe communicating between an interior and an exterior of the housing, with the housing movably attached to the pipe for axial displacement therewith. The housing includes a bottom wall and a cylindrical side wall extending from the bottom wall and terminating in an opening. A switchable valve control having a pod closes the opening. The pod has a plurality of valve seats and a plurality of corresponding valve elements, with the plurality of valve seats defining at least one fluid inlet port and at least one fluid outlet port. The valve elements alternatingly seal the inlet and outlet ports in relation to the axial displacement of the housing, allowing both fluid to ingress through a sealable fluid entry aperture and fluid to egress through the pipe.

Abstract: A positive displacement pump comprises a mass such as a liquid filled pressure chamber or an annular ring which is rotated at high speed about a first axis so that centrifugal force acting on the liquid or ring creates zones of differential pressure within the interior of the pressure chamber or along the wall of the ring. At least one pumping unit having a pressure-responsive member is oscillated or rotated between the zones of differential pressure while the center of gravity of the pressure chamber or ring is maintained at a fixed distance from the first axis. In the course of moving into one zone having one pressure, the pressure-responsive member of the pumping unit is effective to intake a fluid such as air into the pumping unit. Air is discharged from the pumping unit by the pressure-responsive member in the course of moving from such one zone into another zone having a different pressure.

Abstract: Liquid-transfer equipment and method for dispensing liquid reagents for chemical assays, which equipment and method provide time-controlled metering of the quantity of liquid dispensed even though the liquid supply reservoir is not pressurized.

Abstract: A pump for pumping a slurry of frail material is provided by a rigid chamber which is connected to a source of negative air pressure when an inlet valve is open and an outlet valve closed to suck the slurry through the open inlet valve into the chamber, the amount of slurry in the chamber is sensed and when it reaches a preset amount a controller is triggered to disconnect the source of negative pressure and close the inlet valve, and then admit air under positive pressure to the chamber, then open the outlet valve to drive the contents of the chamber through the outlet by replacing a significant amount of the contents with air. The controller then causes the air pressure in the chamber to be reduced and closes the outlet valve, and then reconnects the chamber to the source of negative pressure and then opens the inlet valve to commence a second cycle. The inlet and outlet valves are bladder type valves to protect the frail material and permit simplified operation.

Abstract: A submersible pump casing is supported for limited vertical movement. Buoyancy of the casing changes according to the amount of water in the chamber. When pressurized air continuously supplied to the chamber has discharged most of the water, the casing rises, opening a vent and allowing an inrush of water through a large inlet at the bottom of the casing. A float closes the vent and the cycle repeats. The vent is a simple flapper, and the vent itself is large whereby the filling is quickly accomplished. The flapper is cracked to allow quick opening by a simple push rod and bar mechanism.

Abstract: A gas-operated liquid pump which includes an outer, stationary compartment and an inner compartment movable between upper and lower positions in the outer compartment. The inner compartment has positive buoyancy in the liquid to be pumped. Valve means operated by movement of the inner container is provided to cause gas admitted to the inner container to displace liquid therefrom when the inner container is in its upper position, and to permit gas to escape from the inner compartment when the latter is in its lower position. The pump makes use of a continuous stream of compressed gas such as air to provide a pulsating flow of liquid. The pump is useful in aquariums to create water movement or to pump water to a filter.