Abstract: Provided is a low-noise, long-life electromagnetic blower that has a simple, low-priced configuration and can realize two different outputs, high and low. When the electromagnetic blower is operated with low output, coils of an electromagnet are connected in series with each other, and an alternating current is supplied from an AC power source. When the blower is operated with high output, on the other hand, current is supplied to the one coil only. In the case where the electromagnetic blower is used for sewage disposal, the electromagnetic blower is operated with low output during aeration and with high output during reverse cleaning operation. Thereupon, the electromagnetic blower can operate with low noise during aeration, and the efficiency of reverse cleaning can be improved. In order to operate the electromagnetic blower with high output, moreover, the coils of the electromagnet may be connected in parallel with each other.

Abstract: A system and method for controlling a compressor (1) is provided that prevents the piston (5) of the compressor from colliding against the valve system (8, 9) provided therein. The system and method of the present invention control the stroke of the piston (5), allowing the piston (5) to advance as far as the end of its mechanical stroke in extreme conditions of load, without allowing the piston (5) to collide with the valve system (8,9). The present invention controls the compressor (1) by measuring a movement time of the piston (5); comparing the movement time with a foreseen movement time; and altering the voltage (Vm) if the first movement time is different from the foreseen movement time, the foreseen movement time being such that the movement of the piston (5) will reach a maximum point (M).

Abstract: A method and apparatus for controlling a compressor suitable for delivery of pressurized fluid to a pressurized fluid system, wherein the delivery of the pressurized fluid to the pressurized fluid system can be cycled on and off as a function of a temperature signal received from a temperature sensor. The delivery of pressurized fluid is turned off when the temperature signal exceeds a temperature limit value that is based on the backpressure caused by the pressurized fluid system. Time criteria can be superposed on the temperature limits for controlling the activation and deactivation of the compressor. A preferred area of application of the invention is in vehicle pneumatic suspension systems, including systems having multiple modes of operation.

Abstract: A fluid pumping system includes a number of stages. Each stage has a fluid chamber having a top end with an air aperture and a bottom end with a fluid apertures. An air line is connected to the air aperture, and a fluid input conduit, with an input check valve, is connected to the fluid aperture. A float valve is disposed in the chamber directly between the fluid aperture and the air aperture. A fluid output conduit is connected to the fluid aperture above the input check valve. The float has a bottom end adapted to seal with the fluid aperture when the chamber is empty. A first set of pumping stages are supplied by a first compressed air line and a second set of pumping stages are supplied by a second compressed air line. Periodically, compressed air is supplied to a first set of pump stages to drive fluid from each of the first set of pump stages to a second set of stages, and vice versa.

Abstract: An electronic control system dynamically varies the output capacity of a compressor by controlling plural valves associated with the compressor to provide pressurized air to a distribution system at an appropriate rate. The control system operates in any of three modes for standalone operation, including continuous run, auto/dual pressure band, and target pressure modes. In the first two modes, pressure bands are dynamically calculated based on load and unload values entered by an operator. These electronic control systems can also be connected in a peer-to-peer network to coordinate control of up to 16 compressors feeding the same distribution system, so as to maintain a desired target pressure in the system. A modem connected to the system supports remote diagnostics, monitoring, and control. Specialized startup, operating, and shutdown diagnostic algorithms prevent damage to the compressor and avert unsafe operating conditions.

Abstract: An oil-free dry screw compressor system is provided and includes a variable speed drive and motor along with control logic to increase or decrease the speed of the drive and motor based on sensed pressures. By using an electric motor and a rectifier/inverter drive, a variable speed compressor system is provided having a drive system that can be stopped and started an unlimited number of times over a given time period. Methods of controlling pressure in a compressor system including an oil-free dry screw compressor are also provided.

Abstract: A method for compensating the offset of a pressure value having the steps: detecting a pressure value, lowpass filtering of the pressure value, storing the lowpass filtered pressure value as an offset value, the lowpass filtered pressure value being stored as an offset value if at least the condition is present that a logical signal has or assumes a first value and a substitute value is stored as an offset value if the logical signal has or assumes a second value. Also described herein is a device for compensating the offset of a pressure value.

Abstract: An electronic control system dynamically varies the output capacity of a compressor by controlling plural valves associated with the compressor to provide pressurized air to a distribution system at an appropriate rate. The control system operates in any of three modes for standalone operation, including continuous run, auto/dual pressure band, and target pressure modes. In the first two modes, pressure bands are dynamically calculated based on load and unload values entered by an operator. These electronic control systems can also be connected in a peer-to-peer network to coordinate control of up to 16 compressors feeding the same distribution system, so as to maintain a desired target pressure in the system. A modem connected to the system supports remote diagnostics, monitoring, and control. Specialized startup, operating, and shutdown diagnostic algorithms prevent damage to the compressor and avert unsafe operating conditions.

Abstract: The present invention involves a dynamic brake for use in a peristaltic (i.e., roller) pump. The dynamic brake avoids backlash, due to counter rotation. In addition, it does not preclude the option of hand operating the roller pump. This is achieved by initiating the braking operation after the roller pump set-point has been set to zero and only after the roller pump has decelerated below a predefined speed (e.g., 20 rpm). In addition, the braking operation is activated for only a very brief period of time (i.e., a period of time required for the pressure in the roller pump fluid conduit to subside).

Abstract: A piston pump propels liquid through a lumen of a flexible tube segment. The pump includes a first tube clamping member, a first set of tube squeezing members, a second tube clamping member, a second set of tube squeezing members and a synchronizing arrangement for activating the members in a sequential order such that fluid in the tube is displaced in a downstream direction.

Abstract: A fluid delivery device, in particular for the delivery of combustion air to a heating burner of a motor vehicle or for the delivery of heating medium, preferably heating air, through a heating medium duct system of a motor vehicle, comprises a delivery member which can be driven to rotate by a drive, a rotary state monitoring arrangement for monitoring the rotary state of the delivery member, and also an operating state sensing arrangement for determining the operating state of a system to be supplied with fluid by the fluid delivery device, based on the monitoring result of the rotary state monitoring arrangement.

Abstract: The present invention relates to a pump for delivering under pressure various liquids including water. The temperature of the handled liquid in a pump casing (1) is detected by a thermistor (51). If an increase in the temperature per time of the handled liquid is greater than a predetermined value, then the pump is shut down, or the flow rate or pressure of the liquid is changed depending on the temperature of the handled liquid detected by the thermistor based on a predetermined control program.

Abstract: A fluid pumping system includes a number of stages. Each stage has a fluid chamber having a top end with an air aperture and a bottom end with a fluid apertures. An air line is connected to the air aperture, and a fluid input conduit, with an input check valve) is connected to the fluid aperture. A float valve is disposed in the chamber directly between the fluid aperture and the air aperture. A fluid output conduit is connected to the fluid aperture above the input check valve. The float has a bottom end adapted to seal with the fluid aperture when the chamber is empty. A first set of pumping stages are supplied by a first compressed air line and a second set of pumping stages are supplied by a second compressed air line. Periodically, compressed air is supplied to a first set of pump stages to drive fluid from each of the first set of pump stages to a second set of stages, and vice versa.

Abstract: A method for controlling the operation of one or more electrically-operated pumps (11, 12) to pump a liquid from a well or sump (10) which, in use, receives a substantially continuous inflow of said liquid, characterized in that the method includes the step of starting or stopping each pump in relation to the approach of a change of tariff for the electricity supplied for the operation of each said pump (11, 12).

Abstract: A controller for managing a plurality of compressors in an efficient manner such that the system uses less energy, has lower maintenance cost and experiences less wear. For a system with multiple compressors the controller has the minimum number of compressors needed to maintain the pressure on at any given time and has no more than one compressor running in an unloaded condition for maximum efficiency. The system can quickly pressure up or down in conjunction with the needs of the system. The controller rotates the order of use of the compressors to spread the time of use and for limiting the number of times during an hour that each compressor can be turned on such that the compressors take turns running and turning on and off for even wear. The system seldom uses more than one compressor unloaded at any time.

Abstract: A dynamometer readout (42, 46) and method is disclosed for obtaining dynamometer information (110) related to pumpjacks (10). For this purpose, a change of pivotal direction of the walking beam (18) may be detected by processor (82) utilizing an encoder component (60) with spaced slots (64) therein and light signal devices (68, 70, 72, 74) positioned to have a spacing different from that of the spacing of the slots (64). Software techniques filter out effects of stray mechanical vibrations. An infrared transceiver (46, 50, 100) of a preferred embodiment includes a radio frequency carrier generator (90) and modulator (88) that produces an infrared signal receivable by a low cost consumer radio receiver. The radio frequency modulation technique for infrared signals (96) and related filtering (98, 102, 104) condition formatted infrared signals for utilization in daylight and through a car window for drive-by downloading of data to second computer (108). A sensor (163) may be substituted for the encoder.

Abstract: A centrifugal fluid pump assembly includes a centrifugal fluid pump and a control device. The centrifugal fluid pump comprises a pump section including a housing and an impeller having a first magnetic material and a second magnetic material and accommodated for rotation in the housing and without contacting the housing, an impeller rotational torque generating section including a rotor having a magnet for attracting the first magnetic material of the impeller and a motor for rotating the rotor, and an impeller position control section having an electromagnet for attracting the second magnetic material of the impeller. The control device has a function of limiting an input of a number of rotations of the motor more than a predetermined number of rotations or limiting an input of a motor-driving current having a value more than a predetermined value.

Abstract: A rod body 30 is formed of magnetostrictive material and includes one end portion 30 fixed, and a piston 35 is fixed to the other end portion 30b of the rod body 30. The piston 35 is slidably disposed within a cylinder 36 in which there is formed a pump chamber 37. A suction port 39 for sucking lubricating oil into the pump chamber 37 is formed in the cylinder 36, while a suction valve 40 for preventing the lubricating oil from flowing out from the suction port 39 is disposed in the suction port 39. In the cylinder 36, there is disposed a nozzle 20 which communicates with the pump chamber 37 and has a sectional area smaller than the lubricating oil passage sectional area of the suction valve 40. There is disposed a coil 43 outside the rod body 30 and, to the coil 43, there is connected a control device 6 for controlling the supply of a current to be supplied to the coil 43.

Abstract: There is disclosed a controlling apparatus for controlling at least one vacuum pump and comprising: at least one vacuum pump having a pump body for sucking a gaseous body from a clean room and exhausting the clean room or the gaseous body and a driving motor for driving the pump body; and a controlling section for controlling the driving motor. The controlling apparatus includes a power measurement device, which measures a driving power to be sent to the driving motor. If the power measurement device measures power which reaches or exceeds a warning value, above a fixed value, then the controlling section switches the state of the at least one vacuum pump from a steady operational state into an unusual event checking state, during which an inspection of the vacuum pump is carried out.

Abstract: A blower supplies compressed air to a predetermined place. The blower is provided with a plurality of compressors, a common air tank for storing compressed air supplied from the compressors, a changeover valve for switching the compressed air taken in from the air tank between a first supply state and a second supply state, and a controller for controlling operations of the compressors and the switching operation of the changeover valve. The controller can select one operation pattern from among a plurality of operation patterns determined by combinations between the compressors and the changeover valve.

Abstract: A progressive cavity pumping system includes a pump housing, a rotor member operatively received in the pump housing, a prime mover coupled to the rotor member for driving the rotor member in first and second directions and a controlling means for actuating the prime mover, wherein the controlling automatically causes the rotor member to be driven in the second direction after shut down or idling of the pumping system. A method of operating the pumping system includes automatically driving the rotor member in a second direction after initiating shut down or idling of the pumping system and prior to start up of the same.

Abstract: A power control system for a turbogenerator which provides electrical power to one or more pump-jack oil wells. When the induction motor of a pump-jack oil well is powered by three-phase utility power, the speed of the pump-jack shaft varies only slightly over the pumping cycle but the utility power requirements can vary by four times the average pumping power. This power variation makes it impractical to power a pump-jack oil well with a stand-alone turbogenerator controlled by a conventional power control system. This power control system comprises a turbogenerator inverter, a load inverter, and a central processing unit which controls the frequency and voltage/current of each inverter.

Abstract: A system and method for controlling the stage of a compressor motor and/or fan motor of a heating, ventilation, and air-conditioning system. Preferably, said system and method are used with a reversible, two stage compressor motor. The method includes, for example, switching at least one contactor connected to a source of line power to remove the source of line power to a set of relays and to a compressor motor containing a run winding, a start winding, and a common lead; waiting a predetermined period of time; and controlling the set of relays by switching the set of relays to provide the source of line power to permit switching the source of line power to either the run winding or the start winding, wherein prior to the step of controlling, the at least one contactor removes the source of line power from the set of relays.

Abstract: Hydraulic actuator. An actuator body includes an inlet, an outlet, a port communicating with a pre-charged diaphragm tank, and a port communicating with a pressure switch. The actuator body includes a movable member which, in a first position, closes the inlet port and provides fluidic communication with the pressure switch port while allowing pressure equalization between the inlet and an interior of the actuator body. In a second position, the movable body opens the inlet port and seals the pressure switch port. A spring is disposed within the actuator body to urge the movable member toward the first position. The invention eliminates the need for multiple springs as shown in one prior art design and eliminates the need for reliance on a hydrostatic force differential to move the movable member.

Abstract: A hydraulic pump assembly (10) for powering a hydraulic torque wrench (24) is air-powered and has hydro-pneumatic control circuitry (39) which continues operation of an air motor (18) which drives the hydraulic pump (16) for a post-advance period after an advance actuator (55) is deactuated. Operation of the pump (16) is continued for a period sufficient to retract a double-acting torque wrench (24), to permit subsequent advances of the wrench (24) within the post-advance period without restarting the pump (16) or to permit a single acting wrench to be moved from one fastener to the next within the post-advance period without restarting the pump (16). Operation of the pump (16) is terminated when the post-advance period expires if the advance actuator (55) is not reactuated, so as to conserve energy and avoid unnecessary heating of the hydraulic fluid.

Abstract: A dynamometer readout (42, 46) and method is disclosed for obtaining dynamometer information (110) related to pumpjacks (10). For this purpose, a change of pivotal direction of the walking beam (18) may be detected by processor (82) utilizing an encoder component (60) with spaced slots (64) therein and light signal devices (68, 70, 72, 74) positioned to have a spacing different from that of the spacing of the slots (64). Software techniques filter out effects of stray mechanical vibrations. An infrared transceiver (46, 50, 100) of a preferred embodiment includes a radio frequency carrier generator (90) and modulator (88) that produces an infrared signal receivable by a low cost consumer radio receiver. The radio frequency modulation technique for infrared signals (96) and related filtering (98, 102, 104) condition formatted infrared signals for utilization in daylight and through a car window for drive-by downloading of data to second computer (108). A sensor (163) may be substituted for the encoder.

Abstract: Described is a method and device for servicing the water of a swimming pool 1 by adding a disinfectant. The disinfectant is added by circulating the water through a branched circuit of the pool using a constant flow stirring pump 5. The operation of the pump is determined by the temperature of the water detected by temperature sensor 30 located within the branched circuit. The operating time of the pump is determined according to preset programs of a control box 3 which divide the operating time into time slot units of similar duration spread over several time ranges. The disinfectant addition can be carried out by pebble support 64 or by electrolysis within the branch circuit. Also, if the temperature drops below a minimal freeze risk value or above a maximal value, the pump is continuously operated and a warning is generated.

Abstract: In a hot and cold water distribution system, cooled down water in the hot water distribution line is automatically drained toward the cold water distribution line by a connection system consisting essentially of a centrifugal pump in series with a valve oriented to prevent the flow of cold water into the hot water distribution line or of hot water into the cold water distribution line by the same valve.

Abstract: Lift pump guard for a pump operable by an electrical motor. The lift pump guard monitors variable parameters and actuates a relay to electrically terminate operation of the pump motor when the pump is dry running. Also a method of protecting a pump from dry running compares a measured parameter to a predetermined value and terminates operation based on the comparison.

Abstract: A dynamometer readout (42, 46) and method is disclosed for obtaining dynamometer information (110) related to pumpjacks (10). For this purpose, a change of pivotal direction of the walking beam (18) may be detected by processor (82) utilizing an encoder component (60) with spaced slots (64) therein and light signal devices (68, 70, 72, 74) positioned to have a spacing different from that of the spacing of the slots (64). Software techniques filter out effects of stray mechanical vibrations. An infrared transceiver (46, 50, 100) of a preferred embodiment includes a radio frequency carrier generator (90) and modulator (88) that produces an infrared signal receivable by a low cost consumer radio receiver. The radio frequency modulation technique for infrared signals (96) and related filtering (98, 102, 104) condition formatted infrared signals for utilization in daylight and through a car window for drive-by downloading of data to second computer (108).

Abstract: When a steplike reference signal is supplied while a switch is open, an offset signal for compensating for the dead time of a pneumatic device is generated by an offset generator and supplied as a manipulated variable for the pneumatic device. When a feedback increases in level and a speed higher than a reference speed is detected by a speed detector, the switch is closed by a switching signal, switching from a PD control mode to a PID control mode. The pneumatic device thus controlled has a reduced response time and can made a quick response.

Abstract: A cooling apparatus for electrical equipment having heat-generating components, air-intake apertures and air-outlet apertures includes a fan, a forward-rotation power control circuit, a reverse-rotation power control circuit, an indicator, a long-term timer and a short-term timer. The forward-rotation power control circuit rotates the fan in a forward direction such that air flows in through the air-intake apertures, over the heat-generating components and away through the air-outlet apertures, in response to a forward-rotation command signal. The reverse-rotation power control circuit rotates the fan in the opposite direction. The long-term timer continuously applies the forward-rotation command signal to the forward-rotation power control circuit during a first predetermined period. The indicator indicates the expiration of the first predetermined period.

Abstract: To be used with a pool assembly of the type including a swimming pool, and a pool pump, a self regulating pool heater unit having a refrigeration unit structured and disposed to emit heat in order to heat a quantity of water cycled therethrough by the pool pump. Further, a power source is included and connected to the refrigeration unit, and to the pool pump through a timer. The timer has an on mode which sets a predetermined time period during which the power supplied by the power source flows therethrough to the pool pump so that it will function, and an off mode wherein no power flows through the timer to the pool pump. Additionally, an automatic timer bypass is included and connected in line between the power source and the pool pump.

Abstract: A system and a method are provided for velocity modulation to create pulseless delivery of a fluid by a pump, particularly a piston pump. The system and method require input of data, such as a user-entered dispense rate or analog current or voltage input proportional to a desired output rate. A timer or counter is pre-loaded from a lookup table stored in a processor. The time or counter is started and, upon detection of an overflow condition, the motor and table pointer are incremented one step. As a result, pulseless operation of a pump is achieved.

Abstract: An energy efficient electric control circuit for tankless automobile tire inflater machines wherein, in combination with an air pressure vent port, a current-draw tire inflation analog is created, said control circuit having current sensing means for tracking said inflation analog with such precision that virtually no extraneous compressor operation is experienced. The compressor operation is terminated promptly after tire inflation activity is completed rather than after a more prolonged fixed-time period.

Abstract: A control system is disclosed for a swimming pool or a spa recirculating system. Water is withdrawn from a pool or spa by a pump and supplied, through a filter, back to the pool. As is common with such systems, a controller is operated to initiate operation of the pump at pre-established time intervals (for example, once every twenty-four hours). The length of time or duty cycle that the pump is operated at each of these time intervals is determined by a temperature sensor which senses the water temperature. The temperature sensor supplies a signal to the controller to cause the pump to be operated for a longer period of time when the water temperature is above a threshold temperature, and to be operated for a shorter period of time when the water temperature is below the predetermined threshold.

Abstract: A well pump storage and delivery assembly includes at least one collecting tank coupled to at least one source of water being derived from an underground well having a well pump therein. The collecting tank has an upper water level measuring member capable of detecting and measuring an upper level of water collected within the collecting tank and a lower water level measuring member capable of detecting and measuring a lower level of water collected within the collecting tank. A pressurization pump is connected to the collecting tank and is capable of receiving water therefrom. The pressurization pump is connected to a pressurized storage tank.

Abstract: The present invention provides a controller for an air compressor system. The air compressor system includes an air compressor, control unloaders on the air compressor to prevent the air compressor from compressing gases when signaled to unload, an electric motor for driving the air compressor, and a tank for receiving and storing compressed gases from the air compressor. The controller has an adjustable pressure switch to raise or lower the discharge pressure. The differential pressure is pre-set in the pressure switch. The controller includes two methods of operating the air compressor, each of which is manually selected by operating a switch that will designate start/stop control or automatic dual control at the option of the operator. The start/stop control will start the motor when the pressure in the system reaches a predetermined low point. When the preselected high pressure point is reached, a signal is sent to the motor to stop, thereby ending the compressing cycle.

Abstract: An integral oil filter-pump system for an electric power device which involves a cabinet having an oil-filled compartment for containing the power device, as well as a circulation pump for circulating oil through the system, including the compartment for containing the power device.

Abstract: A new pump shut off system for shutting off a pump when there is insufficient fluid to pump through the pump. The inventive device includes a pump with a primary switch for selectively activating and deactivating the pump. A processor is electrically connected to the primary switch. The processor has a timer for measuring a predetermined amount of time. The processor deactivates the pump after the timer measures the predetermined amount of time. The processor also has a flow switch with a flow sensor in an outlet conduit of the pump. The flow switch deactivates the timer to prevent the timer from measuring the predetermined amount of time when the flow switch is activated by the flow sensor when the flow sensor detects fluid flow through the outlet conduit above the predetermined amount during the predetermined amount of time.

Abstract: A controlling device ensures an accurate control of the rotational speed of an engine. When a hydraulic working machine is in a suspended state, the rotational speed of the engine can be changed from a designated rotational speed to a low rotational speed without requiring any specific manipulation by the operator. When all control levers 14 to 21 are shifted to their respective neutral positions to suspend the operation, and the shifting speed of the control lever which is lastly shifted to its neutral position is low, a delay time is set to be longer than in the case of high shifting speed. If the control levers 14 to 21 are maintained in their respective neutral positions after the elapse of the delay time, the engine 1 is changed to the low rotational speed mode. When one of control levers is shifted before the elapse of the delay time, the engine 1 is continuously maintained in the designated rotational speed mode.

Abstract: A hot water distribution system incorporating a pump positioned close to, and between each set of hot and cold water taps to which periodically move the cooled-down water content of the hot water distribution line through the cold water distribution line back to the hot water tank until the total content of the hot water line has a predetermined temperature. The pump is provided with a valve responsive to pump-generated pressure to prevent backflow when the pump is not in use and the pressure in the cold water distribution line is lower than the pressure in the hot water distribution line, such as when water is drawn through a cold water tap.

Abstract: An oil level regulator is disclosed for use in a refrigeration system which has an oil reservoir and at least one compressor with a crankcase for containing oil. The regulator has a body with an interior fluid chamber for receiving oil. An inlet communicates with the fluid chamber of the body and is connected by a conduit to the oil reservoir of the system. An outlet communicates from the fluid chamber through a conduit through to the crankcase of the compressor. A level detecting mechanism is disposed within the fluid chamber for detecting an oil level therein. The level detector mechanism includes a solenoid assembly which is actuated by the detector mechanism when the oil level within the chamber is determined to be at or below a predetermined level. A microprocessor is provided on the regulator which communicates with the detector mechanism and the solenoid assembly.

Abstract: A pneumatic pump is provided including a housing with an inlet aperture and an outlet aperture. A one way valve is mounted on the inlet aperture. A tube has a first end connected to outlet aperture and a second end positioned distant the housing. An air compressor resides in communication with the housing via a conduit. The air compressor serves to continuously elevate the pressure of air within the conduit. A solenoid valve allows the flow of the pressurized air to the housing only upon the actuation thereof. When the solenoid is actuated, the pressure within the interior of the housing is elevated above that of the exterior such that the valve is closed and the water within the housing is excreted through the outlet pipe. Finally, a timer is connected to the solenoid valve to actuate the same at user selected time intervals.

Abstract: An apparatus and method for delivering a fluid during a series of infusion intervals, consecutive infusion intervals being separated by a non-infusion interval, each infusion interval beginning at a predetermined time and having a first predetermined period, and each non-infusion interval beginning at a predetermined time and having a second predetermined period. The apparatus comprises a pump mechanism and circuitry operatively connected to the pump mechanism. The circuitry is configured so that, if the pump is disabled during one of the infusion intervals, the circuitry will determine the length of time the pump is disabled, interrupt the infusion interval while the pump is disabled, and delay the beginning of subsequent infusion and non-infusion intervals for a length of time approximately equal to the length of time the pump is disabled.

Abstract: An improved method and an apparatus for driving a pump motor for a refrigerator dispenser which are capable of feeding-back a water remaining in a discharge hose to a water container of the refrigerator by reversely rotating a pump motor after discharging the water from the water container, for thus preventing the water and the discharge hose from being polluted. The method includes the step of a first step for discharging a water from a water container through a discharge hose by driving a pump motor when a lever switch is turned on, a second step for stopping the operation of the pump motor when the lever switch is turned off and finishing the water discharge, and a third step for feeding back the water remaining in the discharge hose to a water container of the refrigerator after a predetermined time after the second step by reversely rotating the pump motor with respect to the rotation direction of the pump motor in the first step.

Abstract: An electromagnetic actuating mechanism is provided for a centrifugal pump in which a solenoid ring includes a radially inwardly projecting annular seal movable between open and closed positions with respect to a rotary seal which is mounted for rotation with the drive shaft between the expeller and reservoir region of the pump housing. Spring members are engageable with the ring to normally retain the annular seal in the closed position when the pump is not in operation, and a magnetic drive member is selectively energized to initiate movement of the ring in a direction overcoming the biasing elements to shift the ring to an open position when pump operation is initiated. An energizing control circuit is associated with the pump motor to regulate energizing and deenergizing of the drive member.

Abstract: A hydraulic pump assembly for powering a hydraulic torque wrench is air-powered and has hydro-pneumatic control circuitry which continues operation of an air motor which drives the hydraulic pump for a post-advance period after an advance actuator is deactuated. Operation of the pump is continued for a period sufficient to retract a double-acting torque wrench, to permit subsequent advances of the wrench within the post-advance period without restarting the pump or to permit a single acting wrench to be moved from one fastener to the next within the post-advance period without restarting the pump. Operation of the pump is terminated when the post-advance period expires if the advance actuator is not reactuated, so as to conserve energy and avoid unnecessary heating of the hydraulic fluid.

Abstract: An optical liquid level sensor for distinguishing between the presence of oil and vapor within a compressor crankcase. The sensor has a light transmitting window positioned to interface the crankcase interior and a planar side facing the crankcase exterior. A light source and a light sensor are both positioned adjacent the exterior face of the window. The sensor has a first condition when the prismatic face is immersed in oil and a second condition when the prismatic face is immersed in vapor. An electronic circuit having a dual MOSFET switch for alternating current is mounted adjacent the light source and sensor. The circuit provides power to the source and monitors the sensor. When the sensor is in the first condition, the circuit closes the switch. When the sensor detects the second condition, the circuit starts a timer and continuously tests the condition of the sensor. If the first condition is detected, the timer resets to its initial value.

Abstract: A hot water re-circulating system (10) in a building (12) comprising a water pump (36) connected between an auxiliary water return line (28) extending from a hot water faucet (22) to a remote hot water heater (14). The water pump (36) is controlled by a timer/switch (42) located at the hot water faucet (22), so that when the hot water faucet (22) is opened, hot water will come out therefrom. In a second embodiment, two water pumps (82) and (92) are each connected between two auxiliary water return lines (68) and (70) extending from two hot water faucets (58) and (62) to a remote hot water heater (50). Each water pump (82) and (92) is controlled by a timer/switch (88) and (98) located at the hot water faucets (58) and (62), so that when the hot water faucets (58) and (62) are opened, hot water wall come out therefrom.