Abstract: The fluid pump has a casing defining an inlet manifold, an outlet manifold and a plurality of piston chambers between the inlet manifold and the outlet manifold, each piston chamber having a piston therein for drawing fluid into the piston chamber from the inlet manifold and for pumping fluid out of the piston chamber into the outlet manifold, and a spring biased check valve associated with each piston chamber wherein a spring biases each valve toward the piston chamber and seals the piston chamber from the outlet manifold, the improvement comprises: at least one of the check valves having a hole therethrough which provides open communication between the outlet manifold and the piston chamber, blocking and sealing structure associated with the check valve for blocking and sealing the opening, and a mechanism for moving the blocking and sealing structure between a first position wherein the hole is blocked and sealed and a second position whereby the hole is not blocked or sealed, such that when the blocking a

Abstract: A pneumatic pump of the type having a pair of pump chambers each divided by a diaphragm assembly coupled by a main shaft includes a housing having a central valve chamber. An integral counter, mounted in the pump housing, is also coupled to the diaphragm shaft, and provides a count of the number of shaft reciprocations performed.

Abstract: A vacuum pump control apparatus for an evacuating-type waste water collecting system is disclosed. In the system, waste water discharged from houses and facilities is collected into a water collecting tank by vacuum sewer pipes provided with a negative pressure therein, and the waste water collected in the water collecting tank is discharged by a booster pump while the air in the water collecting tank is discharged by a vacuum pump. The vacuum pump control apparatus comprises a gas-liquid ratio detection arrangement for detecting the ratio of the amount of air to the amount of waste water to be collected into the water collecting tank, and a control system for regulating the operating time of the vacuum pump based upon the gas-liquid ratio detected by the gas-liquid ratio detecting arrangement, so that a target value of the gas-liquid ratio is recovered when it falls below the target value.

Abstract: A hermetic motor compressor comprising a shell formed by an upper and a lower cap connected one to the other in such a way that an airtight closure is obtained in the shell, and by feet fixed to the lower cap for positioning the shell in the correct position during its working, the lower cap defining lower cap lateral surfaces having a very large curvature radius connected to first, second, third and fourth curved surfaces. First and second curved surfaces being connected to a lateral plane and third and fourth curved surfaces being connected one to the other, the lower cap defining a sphere-shape in a lower part thereof and a band in the upper part thereof which is joined to the upper cap.