Having Independent Means For Delaying Valve Actuation Patents (Class 417/27)
  • Patent number: 11944412
    Abstract: A blood pressure detection device manufactured by a semiconductor process includes a substrate, a microelectromechanical element, a gas-pressure-sensing element, a driving-chip element, an encapsulation layer and a valve layer. The substrate includes inlet apertures. The microelectromechanical element and the gas-pressure-sensing element are stacked and integrally formed on the substrate. The encapsulation layer is encapsulated and positioned on the substrate. A flowing-channel space is formed above the microelectromechanical element and the gas-pressure-sensing element. The encapsulation layer includes an outlet aperture in communication with an airbag. The driving-chip element controls the microelectromechanical element, the gas-pressure-sensing element and valve units to transport gas.
    Type: Grant
    Filed: June 2, 2021
    Date of Patent: April 2, 2024
    Assignee: MICROJET TECHNOLOGY CO., LTD.
    Inventors: Hao-Jan Mou, Ying-Lun Chang, Ching-Sung Lin, Chi-Feng Huang, Yung-Lung Han, Chang-Yen Tsai, Wei-Ming Lee, Chun-Yi Kuo, Tsung-I Lin
  • Patent number: 11719231
    Abstract: A processing chamber is connected to a lock chamber. For evacuating the lock chamber and/or the processing chamber a vacuum pump system is provided. The latter comprises a vacuum pump equipment having at least one vacuum pump. Further, the vacuum pump system comprises a valve device for connection to the lock chamber as well as a controller. For noise reduction, a cyclically occurring operating parameter is determined by means of the controller. From said parameter it is determined at which point in time the valve is opened such that temporally before the opening of the valve the rotational speed of at least one of the vacuum pumps can be reduced. This results in a considerable noise reduction at continuing good pump-out times.
    Type: Grant
    Filed: November 10, 2017
    Date of Patent: August 8, 2023
    Assignee: LEYBOLD GMBH
    Inventors: Matthias Nahrwold, Michael Pajonk, Dirk Schiller, Daniel Reinhard, Sebastian Walzel
  • Patent number: 11300120
    Abstract: The invention relates to a positive displacement pump 1 for conveying medical fluids, which pump has a pumping chamber 5 and a positive displacement element 15, and to a blood treatment apparatus comprising a positive displacement pump 1. In addition, the invention relates to a method for controlling a positive displacement pump 1 for conveying medical fluids. The positive displacement pump 1 according to the invention has an actuation member 20 in operative connection with the positive displacement element 20 for displacing or deforming the positive displacement element in order to convey the fluid into the pumping chamber or out of the pumping chamber, and a drive device 21 for displacing the actuation member 20. A control unit 14 is provided for to controlling the drive device 21 and an inlet valve 12 and outlet valve 13. The actuation member 20 is in operative connection with the positive displacement element 15 via a working chamber 19 that is filled with gas and has a sealed volume.
    Type: Grant
    Filed: December 17, 2017
    Date of Patent: April 12, 2022
    Assignee: Fresenius Medical Care Duetschland GmbH
    Inventors: Arne Peters, Christoph Wiktor, Gokhan Orter
  • Patent number: 11193482
    Abstract: The purpose of the present invention is to provide an air compressing apparatus capable of establishing a sufficient air-filling rate while reducing noise at the initiation of operations.
    Type: Grant
    Filed: December 17, 2014
    Date of Patent: December 7, 2021
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Zhijia Ren, Yoshiyuki Kanemoto
  • Patent number: 10704550
    Abstract: Liquid injected screw compressor with an inlet valve and blow-off valve; a liquid circuit with injector; a controller for the transition from unloaded to loaded, whereby when unloaded the inlet valve is closed and the blow-off valve is open, and when loaded the inlet valve is open and the blow-off valve is closed, and whereby during an aforementioned transition, when the injection pressure is below a minimum threshold, the inlet valve remains closed and is opened with a certain delay and that there are means to gradually increase the injection during this delay and to open the inlet valve when the injection pressure has reached the minimum threshold.
    Type: Grant
    Filed: September 10, 2014
    Date of Patent: July 7, 2020
    Assignee: ATLAS COPCO AIRPOWER, NAAMLOZE VENNOOTSCHAP
    Inventor: Pieter De Schamphelaere
  • Patent number: 10184671
    Abstract: A method and a heat transfer system for limiting a supply flow (qS) in a heat transfer system which includes a supply conduit (10) with a supply flow (qS) and with a supply entry temperature (TS), and at least one load circuit (2) with a load pump (20) which provides a load flow (qL) with a load entry temperature (TL) and a load exit temperature (TR). The load entry temperature (TL) is set by way of changing the supply flow (qS), wherein the supply flow (qS) is limited to a maximal flow (qS, max), taking into account at least one temperature detected in the load circuit (2).
    Type: Grant
    Filed: June 23, 2015
    Date of Patent: January 22, 2019
    Assignee: GRUNDFOS HOLDING A/S
    Inventors: Carsten Skovmose Kallesøe, Brian Kongsgaard Nielsen
  • Patent number: 9903358
    Abstract: An air compressor comprising an air intake unit for importing air at atmospheric pressure. A cylinder means for compressing air; a storage tank; a first airline extending between the air intake unit and the cylinder means, the first airline being configured to convey air from the air intake unit into the cylinder means; a second airline extending between the cylinder means and the storage tank, the second airline being configured to convey compressed air from the cylinder means to the storage tank; a motor connected to the cylinder means, configured for driving the cylinder means; a valve inserted into the first airline, the valve being configured to be adjustable between a closed condition and an open condition.
    Type: Grant
    Filed: April 6, 2015
    Date of Patent: February 27, 2018
    Assignee: ALLTRADE TOOLS LLC
    Inventors: Hector Ray Hernandez, Dale Harder, David Tarashandegan
  • Patent number: 7731484
    Abstract: The present invention has an object of controlling power consumption by a vacuum pump by varying the number of revolutions of the vacuum pump in accordance with the operating state of a vacuum device. The condition setting part 4 sets the relationship between the operating state of the vacuum device 10 and the rotational speed of the vacuum pump 2 that evacuates the vacuum device 10. This relationship is set to an appropriate value so as to prevent the rotational speed of the vacuum pump 2 from becoming a higher rotational speed than is required. The control part 6, to which external signals S1 through Sn corresponding to the operating state of the vacuum device 10 are input, reads out from the condition setting part 4 and outputs the rotational speed of the vacuum pump 2 corresponding to the external signals. The inverter 8 controls the rotational speed of the vacuum pump based on the output of the control part 6.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: June 8, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidemi Yamamoto, Kohji Tsuji
  • Publication number: 20090041588
    Abstract: An active valve system may be used to improve operation of the suction valve(s) of a positive displacement pump. As appropriate, the active valve system may apply a force to the suction valve directed to open and/or close the suction valve. By quickening the opening and/or closing of the suction valve, the pump may run at a higher speed and operate with less wear. Additionally, the active valve system may allow all suction valves of a pump to be held open for various purposes.
    Type: Application
    Filed: August 8, 2007
    Publication date: February 12, 2009
    Applicant: Halliburton Energy Services, Inc.
    Inventors: Timothy Hunter, Stanley Stephenson
  • Patent number: 6902378
    Abstract: A vacuum system comprises, as an integral assembly, a vacuum pump with drive motor, a purge valve, a roughing valve and an electronic control module. A cryogenic vacuum pump and a turbomolecular vacuum pump are disclosed. The control module has a programmed processor for controlling the motor and valves and is user programmable for establishing specific control sequences. The integral electronic control module is removable from the assembly and is connected to the other devices through a common connector assembly. In the turbomolecular pump system proper introduction of a purge gas through the purge valve is detected by detecting the current load on the pump drive or by detecting foreline pressure. To test the purge gas status, the purge valve may be closed and then opened as drive current or pressure is monitored. After power failure, the controller will continue normal drive of the turbomolecular pump so long as the speed of the pump has remained above a threshold value.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: June 7, 2005
    Assignee: Helix Technology Corporation
    Inventors: Peter W. Gaudet, Robert J. Lepofsky, Alan L. Weeks, Gerald J. Fortier, Stephen R. Matté, Martin Stein, Steven C. Rosner
  • Patent number: 6604908
    Abstract: A system is disclosed for pumping fluids at desired average flow rates by applying a predetermined force to a pump chamber and pulsing an outlet valve of the pump chamber to deliver a fluid therefrom. In some embodiments, pump chambers are provided within removable pumping cartridges that are constructed and configured to be coupled to a reusable pump drive component. In other embodiments, the pumping cartridges include multiple pump chambers, which pump chambers are operated so that a pump flow rate of one pump chamber is a predetermined fraction of the pump flow rate of another pump chamber within the pumping cartridge.
    Type: Grant
    Filed: July 20, 1999
    Date of Patent: August 12, 2003
    Assignee: DEKA Products Limited Partnership
    Inventors: Robert J. Bryant, Lawrence B. Gray, Geoff P. Spencer
  • Patent number: 6461113
    Abstract: A vacuum system comprises, as an integral assembly, a vacuum pump with drive motor, a purge valve, a roughing valve and an electronic control module. A cryogenic vacuum pump and a turbomolecular vacuum pump are disclosed. The control module has a programmed processor for controlling the motor and valves and is user programmable for establishing specific control sequences. The integral electronic control module is removable from the assembly and is connected to the other devices through a common connector assembly. In the turbomolecular pump system proper introduction of a purge gas through the purge valve is detected by detecting the current load on the pump drive or by detecting foreline pressure. To test the purge gas status, the purge valve may be closed and then opened as drive current or pressure is monitored. After power failure, the controller will continue normal drive of the turbomolecular pump so long as the speed of the pump has remained above a threshold value.
    Type: Grant
    Filed: December 3, 1999
    Date of Patent: October 8, 2002
    Assignee: Helix Technology Corporation
    Inventors: Peter W. Gaudet, Robert J. Lepofsky, Alan L. Weeks, Gerald J. Fortier, Stephen R. Matté, Martin Stein, Steven C. Rosner
  • Patent number: 6022195
    Abstract: A vacuum system comprises, as an integral assembly, a vacuum pump with drive motor, a purge valve, a roughing valve and an electronic control module. A cryogenic vacuum pump and a turbomolecular vacuum pump are disclosed. The control module has a programmed processor for controlling the motor and valves and is user programmable for establishing specific control sequences. The integral electronic control module is removable from the assembly and is connected to the other devices through a common connector assembly. In the turbomolecular pump system proper introduction of a purge gas through the purge valve is detected by detecting the current load on the pump drive or by detecting foreline pressure. To test the purge gas status, the purge valve may be closed and then opened as drive current or pressure is monitored. After power failure, the controller will continue normal drive of the turbomolecular pump so long as the speed of the pump has remained above a threshold value.
    Type: Grant
    Filed: August 21, 1995
    Date of Patent: February 8, 2000
    Assignee: Helix Technology Corporation
    Inventors: Peter W. Gaudet, Michael J. Eacobacci, Robert J. Lepofsky, David E. Roche, Alan L. Weeks, Gerald J. Fortier, Stephen R. Matte, Martin Stein, Steven C. Rosner
  • Patent number: 5472032
    Abstract: A gas transfer system is provided for establishing or maintaining a predetermined gas pressure within a plenum, such as a tire. In an exemplary embodiment, the gas transfer system includes a power source, a pressure sensor, a control unit, and a gas transfer mechanism. Preferably, a gas transfer mechanism includes a micromechanical device, comprising one or more pumping units that transfer gas from one pressure zone to another. In one embodiment, pumping is accomplished, in part, by heating the gas within a sealable chamber of a pumping unit to cause the pressure of the gas to increase. In another embodiment, the change in pressure of the gas caused by compression of a tire provides a pumping force. Valves are provided for regulating movement of the gas through the gas transfer mechanism and can include electromechanical valves responsive to signals from the control unit, or passively biased valves responsive to applied gas pressure.
    Type: Grant
    Filed: February 1, 1994
    Date of Patent: December 5, 1995
    Inventors: Patrick H. Winston, Thomas F. Knight, Jr.
  • Patent number: 5443368
    Abstract: A vacuum system comprises, as an integral assembly, a turbomolecular pump with drive motor, a vent valve, a purge valve, a roughing valve, a heater and an electronic control module. The control module has a programmed processor for controlling the motor and valves and is user programmable for establishing specific control sequences. The integral electronic control module is removable from the assembly and is connected to the other devices through a common connector assembly. Proper introduction of a purge gas through the purge valve is detected by detecting the current load on the pump drive or by detecting foreline pressure. To test the purge gas status, the purge valve may be closed and then opened as drive current or pressure is monitored. After power failure, the controller will continue normal drive of the turbomolecular pump so long as the speed of the pump has remained above a threshold value. Otherwise the vent valve will have been opened, and a start-up sequence must be initiated.
    Type: Grant
    Filed: July 16, 1993
    Date of Patent: August 22, 1995
    Assignee: Helix Technology Corporation
    Inventors: Alan L. Weeks, Gerald J. Fortier, Stephen R. Matte', Peter W. Gaudet, Martin Stein, Steven C. Rosner, Robert J. Lepofsky
  • Patent number: 5195874
    Abstract: A multistage compressor includes a lower pressure side compression part, a higher pressure side compression part, an intermediate conduit placing the lower and higher side compression parts in communication, and a cooler disposed midway of the intermediate conduit for allowing gas to flow from the lower pressure side compression part to the higher pressure side compression part and for cooling the flowing gas. The cooler includes a drain outlet port. The compressor further includes an electromagnetic valve disposed at the drain outlet port and a controller for controlling the valve. The valve is opened when the compressor is started or re-started after a pause, is kept open during a predetermined period of time, and is then closed.
    Type: Grant
    Filed: June 10, 1991
    Date of Patent: March 23, 1993
    Assignee: Tokico Ltd.
    Inventor: Akiharu Odagiri
  • Patent number: 5174545
    Abstract: A bleed valve (20) includes a reciprocating sliding element (42) with a circular head (48) joined to an annular wall (50). An annular first chamber (52) defined by the wall (50), the head (48), and the central support (30) has a variable volume dependent upon the relative position of the sliding element (42). The valve (20) includes a housing (22) having a base (26) with first and second annular partitions (62,64) protruding from the base (26). An annular second chamber (66) is defined by the first partition (62), the platform (34) of the central support (30), the second partition (64), and the base (26). An opening (72) in the central support (30) connects the second chamber (66) in fluid communication to the first chamber (52). Control air supplied from an engine source flows through a first bore (78) into the second chamber (66) which is vented to ambient via a second bore (80). The first and second bores (78,80) have a primary and secondary metering orifice (84,86).
    Type: Grant
    Filed: September 26, 1991
    Date of Patent: December 29, 1992
    Assignee: Pratt & Whitney Canada, Inc.
    Inventor: Daniel Blais
  • Patent number: 5160244
    Abstract: A variable-speed pump system comprising: a hydraulic machine having a flow adjusting means and including at least a pumping function; a rotary machine operatively connected to the hydraulic machine and including at least a motor function for rotating the hydraulic machine; a frequency converter for driving the rotary machine; and a control system for controlling variable-speed operation of the rotary machine according to a command signal from an external unit. The pump system also includes an electric power control system, a flow adjustment control system, and a rotational speed control system. The power control system has a negligibly small time constant, compared to the time constant of the rotational speed control system.
    Type: Grant
    Filed: August 8, 1990
    Date of Patent: November 3, 1992
    Assignees: Hitachi, Ltd., Kansai Electric Power Co., Ltd.
    Inventors: Takao Kuwabara, Eizo Kita
  • Patent number: 5147559
    Abstract: A method for removing floating immiscible liquids from a well containing both the floating immiscible liquids and water, where the floating immiscible liquids and water meet at a water interface, by controlling a cone of depression within the well. A removal system for removing said floating immiscible liquids is used including a microprocessor, a discharge water line and an upper water interface sensor where at least a portion of the discharge water line is located within the well. The upper water interface sensor is located within the well at a sensor location.
    Type: Grant
    Filed: May 1, 1991
    Date of Patent: September 15, 1992
    Inventors: Robert W. Brophey, Robert J. Kadwell
  • Patent number: 4940391
    Abstract: In a compressor system, surge detection is provided by sensing the current of the motor driving the compressor and reading oscillations of the current about the average thereof and above and below two opposite threshold levels from such average current and counting the polarity changes within a time interval containing so many samples of the current and defining a sliding window.
    Type: Grant
    Filed: November 7, 1988
    Date of Patent: July 10, 1990
    Assignee: Westinghouse Electric Corp.
    Inventors: Robert T. Elms, Clyde O. Peterson, Gary F. Saletta
  • Patent number: 4664601
    Abstract: An operation control system of a rotary displacement type vacuum pump capable of reducing a starting torque of the vacuum pump includes a suction regulating valve and a pressure sensor for monitoring suction pressure located in a suction passage of the vacuum pump, an inverter electrically coupled to a variable speed electric motor for driving the vacuum pump and a control unit. The control unit is operative, when the vacuum pump is started, to keep the suction regulating valve in a closed position until the value of suction pressure monitored by the pressure sensor reaches a predetermined upper limit value and to gradually increase the rpm. of the variable speed electric motor. The control unit is further operative to produce a signal for increasing or decreasing the rpm of the variable speed electric motor so as to bring the value of suction pressure monitored by the pressure sensor to the vicinity of a predetermined lower limit value.
    Type: Grant
    Filed: July 23, 1985
    Date of Patent: May 12, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Riichi Uchida, Katsumi Matsubara, Seiji Tsuru
  • Patent number: 4650633
    Abstract: A control apparatus and method for restricting liquid flow in a liquid moving pump, usually of the centrifugal type, to prevent pump cavitation and pump prime mover overloading. The control apparatus includes sensors to detect liquid temperature and pressure at the inlet of the pump. It may further include a device such as a current transformer to develop a signal indicative of power consumed by the prime mover of the pump where the prime mover is an electrical motor. The liquid pressure and temperature indications are used to generate a specific indication of the subcooling of the liquid. The temperature indication is used to derive an indication of the instantaneous required subcooling of the pump. The subcooling indication and the required subcooling indication are introduced to a comparator. Should the subcooling of the liquid fail to exceed the required subcooling, a first control signal is generated.
    Type: Grant
    Filed: July 2, 1984
    Date of Patent: March 17, 1987
    Assignee: General Electric Company
    Inventor: Lamont H. Youngborg
  • Patent number: 4646224
    Abstract: A sprinkler system including a controller having a manual data entry device, a processor and a sprinkler controller. Data is entered through the data entry means relating to conditions in each of a number of zones in which sprinkling is to occur with respect to the amount of water needed to be applied to that zone and the soil water infiltration rate. Upon receiving this information, the processor determines for each zone the number of cycles and the length of time in each cycle that water is to be applied not only so that the amount of water applied during each cycle does not exceed the amount of water the soil can absorb during that cycle, but also so that the total amount of water needed by that zone is applied. The processor employs the number of cycles and the length of on time per cycle to organize the cycles for all of the zones, creating an application program.
    Type: Grant
    Filed: December 5, 1983
    Date of Patent: February 24, 1987
    Assignee: L. R. Nelson Corporation
    Inventors: David P. Ransburg, Douglas C. Fletcher, Sven E. Wahlstrom
  • Patent number: 4560323
    Abstract: An apparatus for controlling flow of a fluid having two speed-controlled positive displacement devices for supplying a load with fluid under pressure from a supply at a different pressure with interposed variable-volume buffer containers.
    Type: Grant
    Filed: January 13, 1982
    Date of Patent: December 24, 1985
    Inventor: William R. H. Orchard
  • Patent number: 4443156
    Abstract: A control system for a compressor utilized in transferring natural gas from relatively low pressure wells to a relatively high pressure pipe line incorporating automatic shutdown of the compressor and automatic restart of the compressor in response to certain conditions with the compressor operating at a desired flow rate regardless of upstream fluctuations in pressure. The compressor is unloaded upon shutdown and remains unloaded for a timed duration after startup thereby reducing the required motor size, compressor wear and also eliminating manual startup for most of the usual causes of gas compressor shutdown, such as low well pressure and high discharge line pressure.
    Type: Grant
    Filed: February 10, 1981
    Date of Patent: April 17, 1984
    Inventor: James A. Dunnam, Jr.
  • Patent number: 4432698
    Abstract: A compressor having a starting load reducing apparatus comprises a main compressor body for compressing gas obtained under suction from an intake chamber through an intake valve within a compression chamber, and ejecting the compressed gas through an outlet opening, a motor for driving the main compressor body, a switch for starting the motor by closing, a solenoid mechanism operated by the closing of the switch, for forcibly communicating the compression chamber with the intake chamber, to put the main compressor body into a non-compressing operational state, and a positive thermally sensitive resistor element connected at a stage before a coil of the solenoid mechanism. The solenoid mechanism operates after the switch is closed until the time when the resistance of the positive thermally sensitive resistor element reaches a predetermined resistance.
    Type: Grant
    Filed: November 3, 1981
    Date of Patent: February 21, 1984
    Assignee: Tokico, Ltd.
    Inventors: Takashi Shirakuma, Fujio Nakamichi, Osamu Iguchi
  • Patent number: 4321014
    Abstract: A multiple pumping chamber pump in which the pressures in at least two of said chambers are equal for at least a portion of their pumping cycles, maintains a constant flow of pumped material by utilizing control means that selectively and continually replaces one material pumping chamber with another after the pressures in both of said chambers have equalized and after the outputs of said chambers have been connected to a common output conduit, by gradually and simultaneously causing a decrease in the pumping rate of material from one of said compression chambers and, to the same extent, a corresponding increase in the pumping rate of material from another of said chambers until the material pumping rate from one of said chambers is reduced from its normal pumping rate to zero and the pumping rate from the other of said chambers has been increased to the said normal pumping rate from the said chamber that had its flow rate reduced to zero.
    Type: Grant
    Filed: December 31, 1979
    Date of Patent: March 23, 1982
    Assignee: Polaroid Corporation
    Inventors: William H. Eburn, Jr., Stephen P. Kalenik
  • Patent number: 4315716
    Abstract: A suction control valve adapted to be connected to the suction side of a compressor and comprising a valve housing, in which a valve seat is formed, which co-operates with a valve body which, in its opened position, brings the suction side of the compressor into open communication with the atmosphere. Said valve body is attached to a valve stem which, in its longitudinal direction, is slidably guided in the valve housing for the displacement of the valve body from the closed position to the open position and vice versa. A continuous bore in the valve stem is at one end in open communication with the suction side of the compressor, and opens at the other end into a diaphragm chamber, which is located on the side of a diaphragm facing away from the valve body, which diaphragm is fixed to the valve stem, while the diaphragm chamber is connected to a conduit, which accommodates a stop valve.
    Type: Grant
    Filed: December 5, 1979
    Date of Patent: February 16, 1982
    Assignee: de Backer's Compressoren B.V.
    Inventor: Pieter A. de Backer
  • Patent number: 4273513
    Abstract: In order to more effectively control the operation of surge valves in pumping stations through relatively long pipelines where liquid is pumped to an elevated discharge circuit and avoid excessive waste of water, where there is provided an electric solenoid to effect opening and subsequent closing of the surge valve and an electric circuit that responds to abnormal conditions which will result in a pressure surge of water with the unscheduled pump stoppage due to mechanical or electrical failure. This circuit operates to open the solenoid valve in time for the surge valve to open before the actual pressure surge of water arrives and closes after the surge has spent at least most of its force, so that liquid will be spilled for only a safe period of time. At the same time, the circuit will effect the successive display of pilot lights to indicate its condition at any time.
    Type: Grant
    Filed: October 2, 1978
    Date of Patent: June 16, 1981
    Assignee: GA Industries, Inc.
    Inventor: Louis E. Salina
  • Patent number: 4140436
    Abstract: A device is provided for monitoring and controlling the above-ambient pressure in a system by comparing a net pressure force, produced by the system pressure on a pair of diaphragms having unequal areas, with a net spring force produced by a pair of opposed springs which clamp together a valve member and a valve seat in a pressure-relief member. The valve seat is connected by a passage to a port which is connected to the system pressure. While thus clamped together, the valve member and the pressure-relief member travel together through most of the total stroke created by movement of the pair of diaphragms and activate a microswitch for admitting additional fluid to the system when the system pressure is insufficient. If the net pressure force is sufficiently greater than the net spring force because of excessive system pressure, a port is opened when the valve strikes a stop and the pressure-relief member continues to move.
    Type: Grant
    Filed: August 19, 1977
    Date of Patent: February 20, 1979
    Assignee: Virginia Chemicals Inc.
    Inventors: Ernest W. Schumacher, Hisashi Ebisawa
  • Patent number: 4135860
    Abstract: Method and apparatus for controlling the operation of a motor driven compressor which is automatically unloaded when the receiver pressure reaches a predetermined maximum level and loaded when the receiver pressure reaches a predetermined minimum level by means of pressure actuated electric control means which are time delayed to start and stop the compressor motor and the unloading and loading operation in accordance with predetermined mode of operation.
    Type: Grant
    Filed: June 7, 1976
    Date of Patent: January 23, 1979
    Assignee: Atlas Copco Aktiebolag
    Inventor: Ludovicus J. van Nederkassel
  • Patent number: 4068980
    Abstract: A positive displacement gas compressor includes an inlet throttling valve which has an actuator responsive to a pressure fluid signal for closing the throttling valve. A control circuit for supplying pressure fluid to close the throttling valve includes a time delay device and a pilot operated valve which vents the pressure fluid signal holding the throttling valve closed after a predetermined time period commencing with startup of the compressor.
    Type: Grant
    Filed: October 1, 1976
    Date of Patent: January 17, 1978
    Assignee: Gardner-Denver Company
    Inventors: Gary J. Fine, Michael G. Herschler, John C. Shoop
  • Patent number: 3981618
    Abstract: The speed of an engine driven pump is sensed and compared with the desired maximum operating speed to detect overspeed. The discharge of the pump is controlled by a variable flow rate controller. When an overspeed condition exists, a command signal is sent to the discharge controller to reduce flow by a discrete decrement. The control signal is blocked after activating the controller for a preselected time interval. During the blocking interval the engine speed is maintained substantially at the operating speed by cyclical reduction of the power input thereto.
    Type: Grant
    Filed: February 14, 1975
    Date of Patent: September 21, 1976
    Assignee: Grumman Aerospace Corporation
    Inventor: George R. Nelson, Jr.
  • Patent number: 3951568
    Abstract: A pump check valve control apparatus includes a pump for delivering a fluid to a system. A valve between the pump and the system controls the delivery of the fluid to the system. A valve actuator, signalled by an actuator control, begins to open the valve when the pressure on the pump side of the valve substantially equals the system pressure. During the opening cycle of the valve, a substantially constant pressure is maintained in the system. The actuator control closes the valve so that flow through the valve ceases when the pressure differential across the valve is substantially zero.
    Type: Grant
    Filed: January 29, 1974
    Date of Patent: April 20, 1976
    Assignee: General Signal Corporation
    Inventor: William L. Carlson, Jr.