Abstract: An unloader apparatus for a gas compressor having a compressor cylinder and a reciprocating compressor piston slidable in the compressor cylinder. The unloader apparatus comprises a hollow sleeve positioned in a suction line of the gas compressor with a port therethrough for communicating gas from the suction line to a suction valve. An unloader piston is slidably disposed within the hollow sleeve and is movable between an open position opening the port whereby gas flow to the suction valve is prevented and a closed position closing the port. In its closed position, the unloader piston seals the compressor cylinder and the compressor piston reciprocates in a partial vacuum. Actuating means connected to the unloader piston is provided for moving the piston between its respective positions. The actuating means utilizes high pressure gas from the discharge side of the compressor for sliding the unloader piston between its positons and exhausts the gas to the suction side of the compressor.

Abstract: A piston type fluid pump which can maintain its prime even though the source of fluid from which the pump draws its supply becomes empty. The pump is capable of pumping its discharge into a pressure vessel as well as to the atmosphere if desired. The pump assembly includes a discharge chamber that receives discharged fluid from the pump and for ultimate delivery to the outflow of the pump assembly. The discharge chamber is of a volumetric size at least equal to or greater than the volume of the effective pumping chamber of the piston so that any air that enters the pumping chamber from the supply or inlet side of the pump remains at the top of the pumping chamber and is discharged into the discharge chamber and the pumping chamber remains full of fluid and consequently primed.

Abstract: A vane compressor is provided with a discharge rate control device which comprises valve means arranged to close part of the fluid suction passage leading to the pump working chambers to vary the opening of the fluid suction passage, and valve driving means for controlling the valve means. The valve means may be formed of at least one valve disposed to close an associated one of the inlet ports opening in the pump working chambers. The discharge rate control device may be arranged to be operated as a function of the rotational speed of the rotor of the compressor or the temperature of fluid being sucked into the compressor, which makes it possible, for instance, to keep the refrigerating capacity of an air conditioning system associated with the compressor at a substantially constant value.

Abstract: A multi-cylinder reciprocating compressor is disclosed which is provided with an unloader valve for blocking the flow of suction gas to at least one of the cylinders to reduce the compressor capacity. The unloader valve is disposed at one end of a cylinder bank and comprises an unloader piston and an unloader port which is an integral part of the cylinder bank. A chamber in which the unloader piston and unloader port are located is formed in the cylinder bank with its axial center in parallel alignment with the axial center of all the cylinders in that bank. This improved efficiency, facilitates ease of manufacture, and reduces associated costs.

Abstract: An electromagnetic plunger pump includes a plunger which is electromagnetically activated. Normally, the plunger is supported in a balanced condition by a pair of opposing springs. Further, the plunger is vertically pierced by a hole extending along an axial line in which the plunger reciprocates in the vertical direction, responsive to an application of an intermittent electromagnetic force. A valve body is loosely fitted into a rod inserted in the vertical hole, reaching a contact portion of a discharge plunger, which interlocks with the electromagnetic plunger. The discharge plunger is forced shut by a spring acting in the valve closing direction. The valve body engages a valve seat to close a discharge passage during a pump shut-down. The valve body is liberated from the valve seat to open the discharge passage during pump operation.

Abstract: A reciprocating gas compressor of the multicylinder, radial type is disclosed which includes unloading means for selectively shutting off suction gas flow to one or more of the cylinders in order to vary the capacity of the compressor. The unloading means include a valve element having a flat, planar surface which is movable between first and second positions with respect to a generally planar valve seat surrounding the inlet of the suction flow passage means, which inlet is spaced radially from the crankshaft axis and lies in a plane substantially perpendicular thereto.

Abstract: A pump assembly for an hydraulic braking system comprises a housing having an inlet for connection to a tank for liquid, an outlet for connection to an hydraulic accumulator, and a piston reciprocably mounted in a bore in the housing to draw liquid into a working chamber during an induction stroke and to force it to the outlet during a power stroke. A drive mechanism is provided for moving the piston in one direction during the induction stroke, and the piston is moved in the opposite direction during the power stroke by subjecting the piston to pressure at the outlet.

Abstract: A marking device wherein liquid is dispensed through the interfacial spaces in a bank of thin blades to an article pressed into engagement with the lower ends of the blades and wherein the flow of liquid to the blades is controlled by maintaining a vacuum in the storage tank which supplies the liquid to the blades characterized in the combination therewith of improved vacuum-producing means by means of which the vacuum of constant predetermined pressure can be maintained with a lesser volume transfer and, hence, with less evaporation of the liquid material, with less work output and, hence, less noise output, and with improved longevity of the apparatus.

Abstract: The disclosure is a system for increasing the reliability of systems for keeping auxiliary liquid-holding tanks filled and reliably functional. A float-operated switch cycles an electric pump to maintain the liquid level between full and nearly full, and a back-flow-preventing check valve is employed and modified (apertured and/or bypassed) to permit slow back leakage to "exercise" the system. The pump, its input to the tank, and the check valve are all located below the pump-turn-on level so that they never lose their prime. One arrangement for testing liquid-level control has a float on a lever arm that operates both the pump-motor-cycling switch and also a low-level switch to energize an alarm. The lever arm also rotates a shaft carrying an indicator dial and/or pointer. The shaft has a manually engageable knob or lever for submerging the float to test the operability of the pump, the alarm, and other parts.

Abstract: A fuel injection valve for an internal combustion engine includes a fuel storage compartment and a pressure chamber from which a reciprocating pump piston delivers fuel to the engine's fuel lines. The fuel conduit between the storage compartment and the pressure chamber can be closed off by an electromagnetic valve. To permit engine operation even when the electrical system is non-functional, the magnetic valve is of the normally open type, held open by a spring. In the energized state, the valve closes off the fuel conduit and its closure is aided by the fuel pressure gradient across the valve.

Abstract: A fuel injection pump for internal combustion engines has a simultaneously reciprocating and rotating pump piston which aspirates fuel from a fuel compartment and then delivers it under pressure to engine fuel lines. An electromagnetic valve can obturate the conduit between the fuel compartment and the pressure chamber of the pump, thereby shutting off fuel delivery. To permit manual override of this shut-off, the electromagnetic valve may be partially unscrewed from the pump housing, thereby lifting the valve closing member from its seat and permitting fuel flow. In another version, an externally accessible central valve bolt partially lifts the valve-closing member from its seat.