Abstract: The cylinder of a reciprocating compressor is provided with a flanged collar defining an annular recess adjacent the side walls of the cylinder bore disposed for entry of the piston skirt during the downstroke into the recess, compressing gas therein. Communication is provided between the recess and the space above the piston and cylinder head, increasing the initial pressure above the piston and causing greater pressure to be developed during the compression stroke. The result is an increase in the volumetric efficiency of the compressor.

Abstract: An ink liquid supply system for an ink jet system printer includes an ink liquid reservoir for containing ink liquid therein, and a compact size plunger pump for supplying the ink liquid to a nozzle. The compact size plunger pump integrally includes three pressure chambers defined by coaxially connected pistons. The pistons are driven to reciprocate by a plunger associated with an electro-magnetic solenoid. The first pressure chamber functions to introduce the ink liquid from the ink liquid reservoir and develop the ink liquid toward the nozzle. The third pressure chamber functions to introduce an ink liquid collected by a beam gutter of the ink jet system printer for returning the ink liquid to the ink liquid reservoir. The second pressure chamber functions as a damper for decelerating the shift movement of the pistons and plunger, thereby reducing the shock which will be created when the plunger is attracted by the electromagnetic solenoid.

Abstract: The pump comprises a pump stator (5), an electric motor stator (4), and a rotor (6) that constitutes the rotor both of the pump and of the electric motor. The pump stator comprises a tubular non-magnetic lining to the electric motor stator, and the rotor is mounted excentrically inside said tubular lining and is equipped with radially movable vanes (63) that co-operate with said lining to provide pumping action when the rotor rotates. The arrangement is particularly applicable to oil-sealed vacuum pumps, and has the advantage of being more compact than units of similar performance, but equipped with a pump and a motor that are separate and interconnected by a mechanical coupling, as is conventional practice.

Abstract: In a small reciprocating pump, an annular space is provided between a cylinder and a cylinder block. The cylinder is bifurcated at its upper end, and has two projecting edges. One of these projecting edges is radially outwardly spaced apart from the other, and greater in length than the other. A cylinder head has a lower surface provided with an annular groove in which the outer projecting edge of the cylinder is engaged. A seal ring is disposed in this annular groove, and another seal ring between the projecting edges of the cylinder to maintain the cylinder in gastight contact with the cylinder head. The other seal ring also serves to support a metal plate which forms therein a valve. The cylinder head is provided with an intake passage having an intake valve, and a discharge passage having a discharge valve. The cylinder block is connected to a crank case in a gastight fashion. A crankshaft is supported rotatably in the crank case for reciprocating a piston in the cylinder.

Abstract: The cryogenic reciprocating pump includes a pump body having a cylindrical pumping chamber extending from the forward end of the pump body to the pump body rearward end. A piston is reciprocated in the pumping chamber under the control of a piston rod extending from the pumping chamber. A packing assembly surrounds the piston rod and is coupled through an intermediate section to the rearward end of the pump body. The intermediate section comprises a tubular shell of low thermal conductivity material and a corrugated metal expansion member. The packing assembly is affixed to a support member connected to the pump body at the forward end thereof.

Abstract: A two-stage gas compressor in which a double acting piston reciprocates in a cylinder in a housing and on a stationary member in which unnecessary compression of gas in the piston interior is avoided and in which gas bypassing the piston rings is prevented from leaking out of the compressor. The piston includes a set of piston rings at each end and between the piston and the stationary member and is actuated by a piston rod sealingly extending through the housing. An opening is provided through the wall of the piston between the two sets of piston rings and a passageway in the housing extends between the compressor first-stage inlet and the piston opening whereby any gas bypassing any of the piston rings and accumulating in the piston cavity will pass to the low pressure first-stage inlet and away from the piston rod packing.

Abstract: A swash-plate type compressor is provided with an improved internal arrangement for lubricating internal moving elements, such as bearings, pistons and shoes wherein a passage is provided for introducing a foam of the lubrication oil, which was generated in the reservoir at the moment of starting the compressor, into the swash-plate chamber and the cylinder bores for lubricating the internal moving elements. The improved internal arrangement further contributes to effective employment of the blow-by refrigerant gas for the distribution of lubrication oil to the bearings and the cylinder bores.