Abstract: An improved type of valve in particular for air compressors is described. The main characteristic of the present invention lies in the fact that it includes a strip in which are formed two substantially U-shape slots passing therethrough, facing towards one another, which define a central portion, two intermediate portions constituted by a respective tongue fixed to a closure plate of a cylinder, and a perimetral portion. In the plate, in correspondence with the central portion and the perimetral portion, there are formed orifices for passage of a fluid, which orifices are alternatively closed or opened by the said central portion and perimetral portion.

Abstract: A rotary compressor unit includes a compressor, a suction valve which holds a suction line of the compressor closed before it is started and which opens the suction line of the compressor after the compressor is started by means of using the negative pressure in the suction line of the compressor, which acts on the suction valve, and a balancing valve which assists the suction valve to open the suction line smoothly and surely.

Abstract: An easily viewed control panel structure indicating the status of and controlling the operation of a water, wastewater or process liquid pumping station where the pumping equipment is operated automatically with respect to a varying liquid level or pressure, liquid level is sensed over a calibrated range, the sensed level information is sent to a controller as a proportional signal, the value of the level of pressure information is displayed on a multi-element, vertically-oriented light-emitting diode bar graph display with each element representing a uniform increment of the total level or pressure range, a circuit-connecting programming pin is inserted in each of several vertically positioned receptacles of the control panel with each such insertion at each horizontal level representing a segment of the level display bar graph, with each receptacle representing a turn-ON or turn-OFF capability of the controller and with two such receptacle circuits combining to provide differential level automatic control o

Abstract: A method is disclosed for operating a large motor-driven refrigeration gas compressor which has independently movable suction and discharge slide valves to prevent undesirable, possibly damaging hydraulic pressure build-up caused by sealing oil remaining in the gas compression chambers during compressor start-up. While the compressor is started and brought up to full speed, the suction slide valve is disposed in fully unloaded position to fully open the gas suction port and the discharge slide valve is disposed in position to fully open the gas discharge port to enable excess oil in the gas compression chambers to exit freely through the compressor gas discharge port before oil pressure build-up can occur. When the compressor is at full speed, the suction slide valve is positioned to maintain a desired gas suction pressure and the discharge slide valve is positioned to equalize gas pressure between the gas compression chambers and the compressor gas discharge port.

Abstract: A pump in accordance with the invention has moving equipment (32) driven by a reversible synchronous motor (42) whose windings (44, 45) are connected to a power source by means of optocoupled triacs (48, 49) which, under microprocessor control, are used to adjust the flow rate of the pump by acting on its admission period (by powering the windings in one direction) and on the pumping cycle time (by varying the period for which the pump is unpowered in each cycle).

Abstract: A regulatable vane pump is provided with a piston operable by differential pressure responsive to booster steering flow demand wherein the piston movement controls a choke bore flow area. The differential pressure is effected by pump pressure on one face of the piston and consumer pressure on the opposite face of the piston, e.g., pressure in a booster steering servomotor. The choke bore has an aperture covered or uncovered by a choke plate carried by a pin on the piston. The choke plate is normally in position so as not to impede flow through the choke and the piston is in a position such that pump outlet flow is blocked from a bypass passage back to the pump inlet. However, with rise in vehicle speed under non-steering conditions, causing pressure on the one face of the piston to shift it along with the choke plate, the choke bore is closed, or partially so, and the unnecessary output pressure flow shunted back to pump inlet.

Abstract: A multiple fluid pumping system uses two or more fluid pumps each driven by a pneumatic piston or plunger and cylinder combination whose piston top stroke and bottom stroke positions are detected by reed switches in combination with a magnet attached to the piston. The top stroke reed switches are connected in series with one side of a two position pneumatic solenoid valve while the bottom stroke reed switches are connected in series with the other side of a two position penumatic solenoid valve. The circuit is designed to prevent one of the pistons from changing the direction of its stroke prior to the other piston reaching the end of its stroke. A further embodiment utilizes a magnet mounted on one pneumatically driven piston or plunger and a pair of reed switches mounted on the other penumatically driven piston or plunger to prevent one piston or plunger from moving faster or slover than the other piston or plunger.

Abstract: A combination heat shield/gasket is disposed between abutting components in a reciprocating compressor. The heat shield/gasket includes strategically located protuberances, at locations where the components do not directly abut, the tips of which contact one of the components causing the heat shield/gasket to locally deflect away from the contacted component. The deflection of the heat shield/gasket at such non-abutting locations causes a dead space to be created between the component contacted by the tip of the protuberance and the heat shield/gasket. The dead space so created is a barrier to the transfer of heat, as is the heat shield/gasket itself, from the component contacted by the protruberances to the area on the side of the heat shield/gasket opposite that side on which the dead space is created.

Abstract: A well-pressure operated pump having a tubular pump body provided with an interior, annular seating surface to receive a valve member mounted on a rod extending through the seating surface. An air spring in the pump body urges the rod upwardly in response to fluid pressure in the pump body and the height of the seating surface and the position of the valve member on the rod are adjustable for adjusting the well pressure at which the valve member is seated. Seal assemblies mounted on the pump body are adjustable to match the pump to the internal diameter of the well casing and the seal assemblies are provided with retainer rings having flanges that capture end portions of a sealing member of each seal assembly. A brake, having a plate that is spring loaded to overlay a shoulder in the bore of the pump body, slows the rate of descent of the pump through gases in the well. An aspirator formed in the support for the plate holds the plate off the shoulder during passage of the pump through liquids in the well.

Abstract: A mowing machine for cutting crop comprises a chassis, cutting members supported by the chassis, and an intermediate structure on the chassis which at least partially supports the cutting members. The cutting members extend on both side of the intermediate structure. The mowing machine also comprises members, such as rotary drums or separating surfaces, which prevent attachment of the crop to the intermediate structure. In a preferred embodiment, the mowing machine further includes conditioning members so that the cutting members and conditioning members comprise a cutting-conditioning group.

Abstract: A pump sprayer has a body with aligned relatively large and small diameter cylinder portions and relatively large and small diameter pistons respectively reciprocable therein and delimiting with the cylinder a variable volume pump chamber during pumping, the small diameter piston shifting relative to the large diameter piston for opening the discharge. Cooperating limit stops acting between the piston members limit the relative movement thereof during a valve open position so as to thereby limit the duration during which the discharge passage is open irrespective of different external reciprocating pressures applied during pumping, such that the output of the sprayer is controlled during pumping.

Abstract: A well pump includes a piston and an inlet and/or outlet valve assembly of special structure. Each is formed of a body of organic polymer, preferably PTFE. Each includes a cavity in its upper portion and at least one passage leading from the cavity to the bottom of the block. A screen covers each cavity and a valve disk covers each screen. Flexible sealing flanges extend upwardly and downwardly from the periphery of the piston block. The outlet valve block has a sliding block and sealing fit with the piston rod.

Abstract: A redundant, pneumatic driver for a blood pump in which a pair of pistons are contained in a common cylinder and their stroke rates and lengths are selectively controlled by a controller which non-invasively senses the circulatory system requirements of the patient in which the blood pump is implanted. The controller varies the stroke rates and lengths to meet such requirements and further is able to selectively switch driving functions from one piston to the other to provide a redundant driving capability.

Abstract: A hydraulic pump with a falling characteristic curve in respect of the output flow relative to the pump speed. A flow control valve (40) has a spool (41) with a hollow (50) extension portion (49), and an annular chamber (52) with two control edges (53, 56) which co-operate with the valve output duct (38) and a relief duct (19) to form restrictor means which are in opposition to each other. The valve output duct (38) and the relief duct (19) are disposed substantially radially with respect to the spool.

Abstract: An axial flow helical screw compressor with a slide valve and slide stop mounted end to end in communication with the intermeshing rotors has means for changing the volume ratio during operation by stepwise movement of the slide stop and for changing the capacity during operation in infinitely variable fashion, both in response to system operating conditions. In the event of interference between the movements of the slide stop and slide valve, the components are designed so that the movements of the slide stop overpowers that of the slide valve.

Abstract: A downhole pump having a gas release probe which probe can be easily applied to a conventional travelling barrel downhole pump by merely lengthening such barrel by providing a variable length spacing sleeve above the travelling valve. The trip rod of the probe lifts off the valve element of the valve from its valve seat to release any gas or foamy oil otherwise trapped between the lower standing valve and the upper travelling valve of the pump. The invention is useful for obtaining oil under subterranean formation conditions that do not normally permit such recovery efficiently due to gas locks and can be either provided in a downhole pump or added to a preexisting pump.The term variable length spacing sleeve is used to describe a spacing sleeve whose length is established to suit a particular operating environment, and which length is determinable by one skilled in the art after considering the various operating parameters of the oil well in question.

Abstract: A positive-displacement single-acting down-hole reciprocating pump for excavating and conveying to the surface accumulations of sand and other detritus that collects at the bottom of producing oil, gas, geothermal, and water-supply wells. The down-hole sand pump is activated by the axial oscillation of a steel cylindrical weighted momentum unit, which, in turn, is axially oscillated by a string of light-weight composite pipe, which in turn is axially oscillated at the surface. The sand and other detritus, along with the circulation fluid, is drawn into suction ports in the down-hole sand pump, and is conveyed upward through the pump, through the weighted momentum unit, and through the light-weight string of composite pipe to the surface.

Abstract: The cryogenic pump operates in two stages, utilizing a supercharging part and a high pressure part. These two parts are comprised of a high pressure piston pump (3, 4, 34, 35) and a supercharger (5, 6, 61, 62) disposed in a tandem relationship and sharing a common piston rod (8). The supercharger is enclosed in a heat insulated intermediate container (7) and delivers the liquid cryogenic fluid to the high pressure cylinder. The pump operates to convey a liquid cryogenic fluid such as liquid nitrogen, for example, at a high pressure through evaporating means into pressure resistant commercial steel cylinders where the gaseous nitrogen is kept at a pressure of 200 bar and ambient temperature.

Abstract: In a liquid ring compressor, the erosion and cavitation damage occurring under certain operating conditions is avoided by adding air or gas from the outside, at a pressure which approximately corresponds to the compression pressure, into particular pressure slot areas.

Abstract: A gas jet pump having a housing and a mixing nozzle holder which, in the area of their flange connection, form a mounting for a mixing nozzle. The mounting comprises on the one hand a clamping groove formed by both flanges in their parting plane, and on the other hand an annular groove in the periphery of the mixing nozzle and a ring made of elastic material located in both grooves. This secures both the axial position of the mixing nozzle relative to the housing and also the sealing.