Abstract: A pressure equalization method and system is provided for starting a compressor while maintaining the compressor at a high pressure and comprises a valve and a bleed port. The compressor has a compressor inlet for receiving a fluid at a first pressure and a compressor outlet for discharging the fluid at a second pressure, and is operable to compress the fluid from the first pressure to the second pressure. The valve is proximate to and in fluid communication with the compressor outlet and is movable to an open position when the compressor is operating to allow the fluid at the second pressure to flow through the valve and is movable to a closed position when the compressor stops operating to prevent backflow of the fluid at the second pressure through the valve toward the compressor inlet. The bleed port is upstream of the valve and in fluid communication with the compressor inlet to equalize the pressure of the fluid contained in the compressor when the compressor stops operating.

Abstract: A centrifugal pump (10) with facilitated self-priming, which comprises a casing (11) with a suction inlet (12) and a discharge outlet and with an internal series (14) of diffusers and impellers, which form a cylindrical assembly that forms, together with the casing (11), an annular interspace which is connected to the inside of the series (14) of diffusers and impellers on the discharge side through corresponding openings (13a) and on the inlet side through a hole (18) arranged perimetrically in the intake region; the hole (18) is controlled, on the side of the interspace (16), by a normally-open flexible metallic laminar valve (19). A wall (20) of the pump struck by the fluid exiting from the interspace (16) through the controlled hole (18) is shaped so as to have a double symmetrical channel (21) for imparting to the fluid a double vortex before passing through the first impeller.

Abstract: A compressor with a capacity modulation system includes a compression chamber, a rotatable shaft within the compression chamber, and a roller mounted on the shaft in contact with a wall of the compression chamber. A suction channel is in fluid communication with the compression chamber for providing fluid at a suction pressure and a discharge channel is in fluid communication with the compression chamber for removing fluid at a discharge pressure. A re-expansion channel adjacent to the compression chamber has a first end forming a re-expansion port in the wall of the compression chamber. A re-expansion chamber is connected to the re-expansion channel. A valve disposed in the re-expansion channel is movable between a first position, in which the valve allows fluid communication between the compression chamber and the re-expansion chamber, and a second position, in which the valve prevents fluid communication between the compression chamber and re-expansion chamber.

Abstract: An oilless high pressure pump suitable for use in devices such as pressure washers and the like is described. The pump includes an eccentric assembly suitable for converting rotary motion of a rotating shaft to rectilinear motion. One or more straps couple the eccentric assembly to a piston assembly. The straps communicate the rectilinear motion of the eccentric assembly to the piston assembly, reciprocating the piston assembly to pump the liquid.

Abstract: A high pressure pump suitable for use in devices such as pressure washers or the like is disclosed wherein the pump's head assembly includes an integral start valve for allowing the fluid through the head assembly so the engine may be more easily started. When the pump reaches a predetermined rate of flow of the fluid, the start valve assembly closes to circulate the fluid through said pump assembly.

Abstract: A positive displacement pump system has first and second delivery passages for pumped fluid and a main delivery passage receiving flow from the first delivery passage and, via a non return valve, from the second delivery passage. A control valve is provided to apportion flow from the first and second delivery passage to an overspill port. A pressure sensitive control orifice is provided in the main discharge passage to receive the combined flows and the control orifice is of variable size.

Abstract: A control for a refrigeration system serviced by a special pulse width modulated compressor coupled to a condenser and evaporator. The system can be of the distributed type wherein the condenser and compressor may be coupled to service a group of adjacent refrigeration cases, wherein each case would have its own evaporator. A controller is coupled to a load sensor for producing a variable duty cycle control signal in which the duty cycle is a function of demand for cooling. Moreover, fuzzy logic techniques may be utilized in order to provide self adaptive tuning control for the system.

Abstract: The apparatus for supplying fuel includes a fuel tank and a fuel feed unit in the fuel tank. The fuel feed unit has a main housing, a suction cover arranged in a bottom part of the main housing, a fuel pump and a degassing valve arranged in the suction cover for degassing the fuel pump. The fuel pump itself includes an impeller housing with a circular passage for fuel flow and an electric-motor-driven impeller. The impeller housing is arranged in the main housing and next to the suction cover and it is provided with a degassing passage connecting the circular passage with the degassing valve. To improve starting behavior the fuel feed unit has a degassing valve in the suction cover, which is connected with the circular passage of the impeller housing by a degassing passage. The degassing valve opens to the fuel tank when pressure in the degassing passage exceeds a predetermined value for degassing the fuel pump.

Abstract: A scroll compressor includes a capacity modulation system. The capacity modulation system has a piston that is connected to the non-orbiting scroll that disengages the non-orbiting scroll from the orbiting scroll when a pressure chamber is placed in communication with the suction chamber of the compressor. The non-orbiting scroll member moves into engagement with the orbiting scroll when the chamber is placed in communication with the discharge chamber. The engagement between the two scrolls is broken when the pressure chamber is placed in communication with fluid from the suction chamber. A solenoid valve controls the communication between the pressure chamber and the suction chamber. By operating the valve in a pulsed width modulated mode, the capacity of the compressor can be infinitely varied between zero and one hundred percent.

Abstract: In a scroll compressor provided with a fixed scroll member (4) and a movable scroll member (3) which define a plurality of compression spaces (6) therebetween in cooperation with each other, a hole (32) is formed to the fixed scroll member to be communicable with adjacent ones of the compression spaces. The adjacent compression spaces are different from each other in pressure when the scroll compressor is driven. A piston valve (33) is disposed in the hole and controls communication between the adjacent compression space through the hole. The compression spaces are movable with volumes reduced by movement of the movable scroll member.

Abstract: A water pump includes a housing having a water inlet, a water outlet, an exit and a mouth. A circulating water passage couples the exit to the mouth of the housing. A pump may pump water from the exit to the mouth of the housing via the circulating water passage. The housing includes two ducts communicating with each other and communicating with the mouth, and the water inlet and the water outlet respectively. Two plugs are slidably disposed in the ducts for switching water to circulate through the exit and the circulating water passage when the water outlet is closed.

Abstract: A dosing pump for dosed liquid conveyance that includes a suction valve built into a suction tube coming out of a suction container, a pump chamber having a displacement volume that can be modified by means of a pumping member, a pressure valve leading to a dosing tube, a deaeration device arranged on the top end of the tube and comprising a return valve and a flow-actuated deaeration and bypass valve built into a deaeration valve having response characteristics dependent upon the state of aggregation of the liquid contained therein. The flow-activated deaeration and bypass valve is open when idle, only closing when pressure is raised in the presence of liquid in the valve, and is provided with a membrane. Faulty pump operation is substantially reduced when the membrane is connected to a remote closing member which closes the deaeration tube when the membrane is moved. A return valve is arranged between the membrane and the closing member.

Abstract: A scroll type fluid machine having a bypass hole structure for capacity control is disclosed. The scroll type fluid machine comprises a first scroll having a first spiral blade, and a second scroll having a second spiral blade. A first fluid working chamber is formed between an inner surface of the first spiral blade, and a second scroll having a second spiral blade. A first fluid working chamber is formed between an inner surface of the first spiral blade and an outer surface of the second spiral blade, and a second fluid working chamber is formed between an outer surface of the first spiral blade and an inner surface of the second spiral blade. A winding end of the first spiral blade is extended so that the first fluid working chamber and the second fluid working chamber open and close with respect to a single low-pressure port. A common bypass hole making the first and second fluid working chambers communicate with the low-pressure port in common is provided.

Abstract: A scroll-type refrigeration compressor is disclosed which incorporates an efficient, reliable, low cost modulation system employing a single actuator to effect switching between full and reduced capacity operation. The modulation system of the present invention includes an annular valving ring rotationally supported on the non-orbiting scroll or main bearing housing which operates to ensure simultaneous opening and closing of one or more unloading passages thus avoiding the possibility of even transient pressure imbalances between opposed compression pockets during operation of the compressor or in one of the alternative embodiments, providing a controlled imbalance to provide a noise reducing torsional loading on the Oldham coupling. Further, the modulation system of the present invention provides for reduced capacity at both start up and shut down thus enabling the use of more efficient lower starting torque motors and reducing the potential for noise generating reverse rotation on shut down.

Abstract: A mechanical seal combination includes a double mechanical seal and a barrier fluid pump system. A barrier fluid circulating pump 10 is coupled to rotatable shaft 3 so as to derive its motive power from the rotatable shaft. When the rotatable shaft is not running, a by-pass arrangement causes barrier fluids to flow between the barrier fluid header tank 7 and the seal 3, avoiding pump 10, and allowing a thermosyphon effect to be created.

Abstract: Difficulties in adapting centrifugal pumps for use as fuel pumps for turbine powered aircraft are avoided in a system including a centrifugal volute pump (22) on a common shaft (18) with a regenerative pump (24). A pressure responsive throttling valve (46) is connected to the inlet (50) of the regenerative pump (24) so as to cause the regenerative pump (24) to provide fuel at a desired, substantially constant pressure while a check valve (80) is connected to the outlet (72) of the centrifugal volute pump (22) to allow flow from the volute (72) but not the reverse. The outlet side of the check valve (80) can also be selectively connected to the outlet (84) of the regenerative pump (24) so that when the pumps are rotating relatively slowly, the regenerative pump (24) will pump fuel at the desired, substantially constant pressure and, as rotational speed increases, the check valve (80) will open when the centrifugal volute pump (22) is pumping fuel at or about the desired substantially constant pressure.

Abstract: A hydrualic power unit for an auto-hoist lift having a more compact motor and improved noise characteristics. The power unit having a reservoir with a closed end and an open end. A manifold attached to the open end and having an inlet port and an outlet port with a hydrualic circuit located between the ports. The hydrualic circuit having a delay valve for reducing the start-up torque load on the motor, thereby allowing the motor to be sized for normal operating requirements rather than oversized for start-up requirements. The power unit may further include a motor and pump located inside a hydrualic fluid reservoir to thereby reduce the amount of noise reaching the immediate vicinity of the power unit. The motor and pump are submerged in the hydrualic fluid to advantageously utilize the hydrualic fluid to cool the motor.

Abstract: An improved valve assembly for automatically priming a hydraulic pump during a suction-fed application wherein the pump must draw fluid from within a holding tank for subsequent pressurization and transmission by the pump. The valve assembly of the present invention is provided in fluid communication with the outlet line of the pump and is capable of sensing the difference between fluid and air such that the air disposed within the pump at start-up may be quickly and efficiently bled from the system before the valve automatically closes once the fluid has been drawn into the pump in an amount sufficient to bring the pump into a fully primed condition. The valve assembly includes a housing member, a poppet member, a biasing means, and sealing means. The housing member includes a bore extending between an inlet aperture and an outlet aperture, and a slotted shoulder member extending radially inward from the inlet aperture.

Abstract: A multicylinder rotary compressor capable of performing high performance capacity control operation without the need for an external piping or for a thicker partition plate which leads to a taller rotary compressing element or a longer bearing span of a bearing. The multicylinder rotary compressor has a rotary compressing element housed in a hermetic enclosure; wherein the rotary compressing element is equipped with an intermediate partition plate, a cylinder provided on each side of the partition plate, a rotary shaft having eccentric sections which are shifted relative to each other by 180 degrees in the direction of shaft rotation, rollers fitted onto the eccentric sections of the rotary shaft and which rotate in the cylinders, and bearings which seal the cylinders.

Abstract: A flow-responsive diverting valve is particularly useful with pressure washers of the type having a water pump coupled to an internal combustion engine equipped with a pull-rope starter. The valve provides an "easy-start" feature and has a valving chamber and a fluid inlet and two fluid outlets. A magnet is fixed on the valve body and when fluid flows into the inlet at the low flow rate occurring when operating the starter, a valving device, e.g., a check ball, is restrained by the magnet. When fluid flows into the inlet at a higher flow rate (as when the engine is running and the pump is delivering water at a substantial rate), the device closes the first outlet and diverts water to the second outlet. A method for operating a pressure washer includes magnetically restraining the valving device away from the first outlet while operating the starter and then running the engine, thereby urging the device to close the first outlet.

Abstract: A fuel supply unit adapted to supply a relatively constant flow of fuel oil to an oil burner independently of the pressure of the fuel at a discharge port. The fuel supply unit includes a pump which draws fuel oil from a storage tank and which supplies pressurized fuel to an outlet chamber. The fuel then flows from the outlet chamber to the burner by way of the discharge port. A metering orifice is located between the outlet chamber and the discharge port to control the flow rate of the fuel delivered to the burner, the volumetric flow rate of fuel being related to the pressure differential across the metering orifice. A regulating valve senses the pressure of the fuel at the discharge port and adjusts the pressure of the fuel in the outlet chamber to maintain a relatively constant pressure differential across the metering orifice.

Abstract: A scroll-type refrigeration compressor is disclosed which incorporates an efficient, reliable, low cost modulation system employing a single actuator to effect switching between full and reduced capacity operation. The modulation system of the present invention includes an annular valving ring rotationally supported on the non-orbiting scroll which operates to ensure simultaneous opening and closing one or more unloading passages thus avoiding the possibility of even transient pressure imbalances between opposed compression pockets during operation of the compressor or in one of the alternative embodiments, providing a controlled imbalance to provide a noise reducing torsional loading on the Oldham coupling. Further, the modulation system of the present invention provides for reduced capacity at both start up and shut down thus enabling the use of more efficient lower starting torque motors and reducing the potential for noise generating reverse rotation on shut down.

Abstract: In a scroll type compressor, when the operation of the compressor is stopped, compression chambers, for compressing a fluid, and a suction chamber are communicated with each other through bypass holes, and a spool valve to open and close the holes, so that the pressure in the compression chambers are lowered and the occurrence of a shock caused by a sharp increase in the load is prevented at the next start. Since the discharge pressure to drive the spool valve is introduced from a position upstream of the discharge valve, pressure is quickly lowered when the compressor stops, so that the spool valve can be quickly opened. Therefore, even when the compressor is frequently started and stopped, the occurrence of a shock can be positively prevented when the compressor starts.

Abstract: A valve housing has a chamber formed therewithin, and an inlet and an outlet for accommodating fluid flow through the chamber along a given flow path. The housing further confines a free ball therein, and hydraulic-fluid filed compartments with flexible walls. Intermediate the inlet and outlet, the housing has a valve seat formed. Fluid pressure in the chamber causes one compartment to collapse and the flexible wall of the other to expand. The expanding wall, and capturing fluid flow, moves the ball to the seat to halt flow through the chamber, after an initial period of free flow. The method comprises providing the chambered housing, disposing the ball in the chamber, communicating the inlet with a pump outlet, and confining the flexible-walled compartments in the chamber.

Abstract: A pump with a priming circuit containing a valve having a seating with an orifice and an obturator mounted so as to be able to be applied onto the seating in front of the orifice, where the obturator is a resilient blade embedded on one side to the seating. The flexibility of the blade increases from the embedded side to the other. An L-shaped member protrudes from an outer curvilinear wall of a priming element fixed onto the pump. The L-shaped member allows for the seating to be slide into a groove space. The obturator has two holes so that the obturator can be embedded onto the seat by mating with two projections from the seating surface.

Abstract: Valve system for a vehicle gas suspension system having a central chamber (41) to which pressurized gas is admitted via valve 50 or from which pressurized gas is exhausted via valve 51. Interposed in gas communication paths between the central chamber and each gas suspension unit (46-49) is a respective on-off valve unit (42-45). The valve system includes a regenerative drier (56) and a cushion valve (70) for protecting a compressor from overload during start-up.

Abstract: An improved fluid bypass valve includes a valve housing having an inlet port, an outlet port and a bypass port, all of which are in fluid communication with a valve chamber within the valve housing. A shuttle having a fluid passage therein is disposed within the valve chamber and moves between a first travel limit position, in which fluid communication between the fluid passage and the bypass port is blocked and a second travel limit position, in which such fluid communication is permitted. First and second fluid seals are disposed in contact with interior surfaces of the valve housing on opposite sides of the bypass port, and the shuttle is disposed in sealing and sliding engagement with both the first and second fluid seals when the shuttle is in the first and second travel limit positions.

Abstract: An integral liquid pump and drainback valve for use in pumping popcorn popping oil. A two-part housing is formed with one part having cavities forming inlet and outlet passages extending from an impeller cavity. A second part is formed with inlet and outlet ports and shuttle valve cavity connecting those ports. The inlet and outlet passages and the inlet and outlet ports respectively are in fluid communication with each other when the two parts are secured to each other. A resilient biasing means in the shuttle valve cavity moves the shuttle to a position wherein a fluid path is provided between the inlet and outlet ports when the pump impeller is not driven.

Abstract: A portable compressed air system includes a housing, and a diesel engine having a predetermined torsional inertia, a predetermined cranking speed, and a predetermined idle speed. A centrifugal compressor is flexibly coupled in motive force receiving relation to the diesel engine. The flexible coupling has a predetermined spring rate which places the torsional interia of the compressor above a highest predetermined cranking speed and below the predetermined idle speed of the diesel engine. A microprocessor-based electronic controller controls compressor operation. A receiver stores compressed air. A cooling means cools the portable compressed air system. The cooling means has a fan, an intercooler, an oil cooler, an engine radiator, and an aftercooler. The intercooler, the oil cooler, the radiator, and the aftercooler are arranged in two banks, and each bank is defined by two cooling cores juxtaposed one to each other.

Abstract: An apparatus for loading a compressor includes a microprocessor based electronic controller, a pneumatically driven, spring loaded open first valve, and a normally open, electrically driven second valve flow connected in series with the first valve. The first valve and the second valve are fluidly disposed intermediate a receiver tank and the compressor. The second valve is disposed in signal receiving relation to the controller. An orifice and muffler combination is flow connected intermediate the first valve and the second valve. The orifice has a predetermined inside diameter dimension suitably sized to establish a pressure signal to close the first valve to thereby load the compressor.

Abstract: A variable displacement, scroll-type compressor comprising a housing having fluid inlet and outlet ports. A fixed scroll member, placed within the housing, comprises a first plate from which a first spiral element extends. An orbiting scroll member comprises a second plate from which a second spiral element extends. A pair of holes are formed through said first plate. A pair of bypass passages place intermediately located sealed-off fluid pockets in communication with a suction chamber. A pair of cylinders are formed within respective bypass passages. A valve member having a first and a second axial end is slidably disposed within each of the cylinders so as to close and open the corresponding bypass passage. A spring is disposed within the cylinder so as to urge the valve member to open the bypass passage. The valve member receives pressure at its first axial end from the intermediately located sealed-off fluid pocket.

Abstract: An automatic recirculation valve having an inlet, a main outlet, and a recirculation outlet. A main valve element responsive to the flow between the inlet and main outlet and a bypass element responsive to the main valve element regulates the fluid flow to the recirculation outlet. The bypass element contains orifices through which the fluid flows to the recirculation outlet. The orifices are arranged to counterbalance fluid forces exerted on the bypass element.

Abstract: A variable displacement mechanism for a scroll type compressor opens and closes a communication path between the suction chamber and a pair of intermediately located sealed spaces. The variable displacement mechanism includes a piston valve member slidably disposed within a cavity. The piston valve selectively opens and closes the communication path between the suction chamber and intermediately located sealed spaces. A conduit permanently links the discharge chamber to the upper end surface of the piston valve so that, even when the communication path is established, the upper end surface of the piston valve is constantly exposed to discharge pressure.

Abstract: A variable-displacement vane pump apparatus is composed of a pump part and a switching valve. The pump part is comprised of a housing, a cam ring, a rotor, plural vanes, side plates, two pairs of intake and exhaust ports formed on the side plates, discharge pressure chambers connecting with the discharge ports, and an intake chamber connected with the intake ports. The pump part is divided into first and second pump portions, and only one of the pump portions is activated by the operation of the switching valve when the load pressure is low. Under such condition, the fluid discharged from the particular pump portion is returned to its intake port. Also, the flow rate of the operation fluid discharged from the pump is adjusted by the flow control valve by returning part of pressurized fluid into the inlet ports. A fluid supplied from a reservoir is energized two times by supercharge effect utilizing the returned fluid from the switching valve and the returned fluid from the flow control valve.

Abstract: A system for and a method of establishing and maintaining fluid at desired cleanliness, viscosity and temperature levels in a flow system. The system includes a driven pump that circulates fluid from a fluid source through a hydraulic loading system that includes an unloading valve. As fluid flows through the valve, a pressure drop is created across the valve operator, which restricts flow through the valve. This pressure drop across the valve operator results in the dissipation of heat, increasing the temperature of the fluid flowing through the valve. During operation of the system, if a low temperature condition is sensed in the system, power will be supplied to the pump, which pumps fluid through the valve at a controlled low pressure drop to result in a controlled heating of the fluid. When the fluid is restored to a desired temperature level, power to the pump is discontinued to terminate flow through the valve.

Abstract: A refrigerant compressor to be incorporated in a refrigerating circuit of a car air-conditioning system, having a suction side connected to the refrigerating circuit for receiving a refrigerant gas to be compressed, a discharge side for delivering the refrigerant gas after compression, and a bypass passageway arranged between the suction and discharge sides and constantly closed by a passageway-closing valve, and opened by the passageway-closing valve, only when the lowering of a suction pressure prevailing on the suction side to a pressure level below the atmospheric pressure level immediately after a start of the operation of the compressor at a high speed after a long non-operation of the car air-conditioning system.

Abstract: A scroll type compressor has a pair of bypass ports which communicate with a chamber being compressed which ports are bored in an end plate of a stationary scroll. An inner surface of a capacity control block of the compressor is separate from the stationary scroll and abuts against the outer surface of the end plate of the stationary scroll, thus forming a recessed portion which communicates with the pair of bypass ports therebetween. One cylinder of the compressor communicates with a suction chamber in a housing and is provided in the capacity control block and a piston operating by a control pressure in accordance with a load of the compressor is disposed slidably in the cylinder. A communicaton hole which communicates with the recessed chamber is opened and closed by the piston, thereby controlling the output capacity of the compressor in the range from 0 to 100%.

Abstract: A scroll type compressor has bypass ports which communicate with the compression chambers. The bypass ports are bored in an end plate of a stationary scroll. A capacity control block is contained inside a bypass passage which has the bypass ports communicate with a suction chamber formed in a housing. A valve mechanism which opens and closes the bypass passage is formed separately from the stationary scroll. The capacity control block is engaged with the stationary scroll and installed fixedly in the housing, thereby to control the output capacity of the compressor in a range from 0% to 100%.

Abstract: A radial refrigerant compressor assembly for use in automotive refrigerant systems and capable of being cycled between on and off conditions having a fluid passageway extending between the bottom portion of the discharge chamber which operates at discharge pressure and the suction chamber which operates at a reduced suction pressure. A valve is disposed within the fluid passageway and regulates the flow of lubricant between the discharge and suction chambers under the force of the pressure differential existing between these chambers just after the compressor is cycled on and just after the compressor is cycled off.

Abstract: The pressure side of a submersible pump unit is provided with a valve device which during certain periods of operation opens a connection between the submersible pump and the pump station to obtain the necessary circulation of the waste water in the station. The opening and closing of the valve device is effected by a ball which is controlled by the submersible pump pressure.

Abstract: A flow loading unloader valve wherein the operating force for moving the valve from the unloaded condition to the loaded condition is supplied by the flow through the valve itself. The valve, which may be interposed between a fluid supply and a high pressure load, comprises a valve body, having an inlet, a working outlet, a bypass outlet, and a valve operator, which may include a spool, that controls the direction of flow through the body. Movement of the valve operator to change the valve from the unloaded condition to the loaded condition is accomplished by applying the differential pressure created by the flow of fluid from the inlet to the bypass outlet to the piston ends. As the pressure increases as a result of increased flow resistance through the valve, the valve operator moves from an unloaded to a loaded position, terminating flow to the bypass port and resulting in high pressure flow to the working outlet.

Abstract: A gear pump receives fuel oil from an intake line leading from a storage tank and supplies pressurized fuel to a regulating valve which selectively opens and closes to control the flow of fuel to an oil burner. When the pump first starts but before the regulating valve opens, fuel bypasses the regulating valve and is returned to the tank along with any air that might be in the system, the system thus being automatically purged of air. After the regulating valve opens, excess fuel which is not required by the oil burner is returned directly to the inlet of the pump for recirculation and bypasses both the seal chamber of the pump and the storage tank so as to enable low flow velocity to be maintained in the intake line leading from the tank to the pump and thereby prevent cavitation at the pump when the fuel is of high viscosity. Only a small flow of fuel is directed to the seal chamber to lubricate the shaft of the pump.

Abstract: A volute type centrifugal pump has an impeller rotatably mounted in a volute chamber of the pump casing adjacent a cutwater within the casing. The impeller includes a hub having a pair of diametrically extending vanes with the outer end portion of each vane being angled in a trailing direction relative to the direction of rotation of the impeller. A semi-cylindrical projection having an axis parallel to the axis of the hub is formed on a trailing surface of each angled portion adjacent an outermost end thereof thereby reducing cavitation on the trailing surface of the impeller to reduce drag and turbulence while increasing pressure on the trailing surface. The surface of the semi-cylindrical projection is roughened to enhance hydraulic jump.

Abstract: In a scroll type of compressor having a stationary scroll, a movable scroll opposed to the stationary scroll and rotatable thereabout but not rotatable about its own axis, so that a closed chamber which decreases in volume during the rotation of the movable scroll is defined by and between the stationary scroll and the movable scroll, and an introduction passage through which a coolant is introduced into the compressor, wherein a capacity varying apparatus comprises a suction restriction mechanism provided in the introduction passage to control the cross sectional area thereof in accordance with the pressure of the coolant, a by-pass passage extending through the stationary scroll to connect the portion of the closed chamber connected to start ends of scroll portions provided on the movable and stationary scrolls, while being reduced in volume, to suction pressure area in the compressor, a by-pass opening and closing mechanism provided in the by-pass passage to open and close the latter in accordance with the

Abstract: To facilitate start of a 2-cycle engine, for instance, compression pressure at the first compression stroke is released through the valve to reduce reaction force applied to an engine starter; once the mixture is ignited, explosion pressure at the first explosion stroke and after is accumulated in the accumulator space through the check valve member to keep the valve member closed against the valve spring, so that the engine is operated under the ordinary conditions; when the engine is at halt, accumulator pressure is released through the openable check valve member and the valve member opened by the valve spring to its original conditions.

Abstract: A fluid-operated actuator (2) is connected to a pumping unit (12) through a control unit (10) in which are mounted control valves (30,32) for regulating the movements of the actuator. The control valves communicate with the actuator and the pumping unit through conduits in replaceable adaptor plates (60a,60b,60c). By changing the adaptor plates, different operating modes of the actuator can be selected. The pumping unit is carried on the control unit through a rotationally adjustable connection to permit it to be mounted upright although the orientation of the actuator and control unit may vary.

Abstract: A hydraulic vane-type pump is provided having a venting valve which is located immediately at the pressure space of the pump, i.e., avoiding any additional passage means between the pressure space of the pump and the venting valve.

Abstract: A device is provided for obtaining automatic circulation in waste water pump stations. At the pressure side of the pump unit, there is a valve which opens during certain times to form a connection between the pump and the pump station to create a circulation. The valve is opened and closed by means of communicating bellows which are controlled by the pressure difference between two sections in the valve having different areas.

Abstract: An automatic ice manufacturing apparatus comprises an ice making unit for manufacturing ice in an icing operation cycle, a water tank disposed below the ice making unit for storing water to undergo phase transformation into ice on the ice making unit, a first water spray tube disposed above the ice making unit for spraying the water onto the ice making unit, a water circulating conduit interconnecting the first water spray tube and the water tank, a circulating pump mounted in the circulating conduit for circulating the water between the water tank and the ice making unit, and an overflow pipe disposed within the water tank for controlling the highest water level within the water tank.

Abstract: A pneumatic vibratory diaphragm pump, having a casing (12, 14) comprising an upper chamber (17) having an inlet (59) by which air can be drawn from outside the casing and a lower chamber (16) having an outlet (N) from which air can issue from the casing, an oscillatory armature (22) within the lower chamber to actuate a diaphragm (28b) of at least one diaphragm and valve assembly (28, 30) and drive (80,20) to cause oscillatory movement of the armature. Each diaphragm and valve assembly is arranged so as to induce air to be pumped by it from the upper chamber and to discharge air into the lower chamber whereafter the discharged air is issued from said outlet. Venting means (70, 74, 76) is provided to allow air which has been discharged from the casing into a container to return therefrom and exhaust from the casing when the pump is inactive.