Patents by Inventor Sandra L. Harper
Sandra L. Harper has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5660052Abstract: A heat transfer system includes a high side pressure sensor in the form of a temperature dependent resistance in heat exchange with the system working fluid to locally heat the fluid in response to a control signal. Control means are provided for applying the control signal to the resistance and detecting a minimum thermal resistance between the thermistor and the working fluid.Type: GrantFiled: June 2, 1995Date of Patent: August 26, 1997Assignee: Parker-Hannifin CorporationInventors: Richard L. Kenyon, Roy M. Yabuki, Chester D. Campbell, Sandra L. Harper, Michael Nolan, Virender Jain, Alan Matthies
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Patent number: 5522231Abstract: A mass flow control apparatus and method for use in combination with a heat transfer system having a compressor, condenser, expansion valve, evaporator and working fluid in a fluid circuit. The mass flow is controlled using a quality sensor for the working fluid exiting the evaporator, and a high side pressure sensor. A control circuit is provided that monitors the quality sensor and the high side pressure sensor, and controls operation of the compressor, condenser fan and valve in response thereto. A flow reduction mode is used to reduce high side pressure at the valve inlet without excessive compressor cycling by changing the quality sensor set point when the high side pressure exceeds the condenser fan turn-on pressure but is less than the compressor disengage pressure.Type: GrantFiled: July 26, 1995Date of Patent: June 4, 1996Assignee: Parker-Hannifin CorporationInventors: Richard L. Kenyon, Roy M. Yabuki, Chester D. Campbell, Sandra L. Harper, Michael Nolan, Virender Jain, Alan Matthies
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Patent number: 5477701Abstract: A mass flow control apparatus and method for use in combination with a heat transfer system having a compressor, condenser, expansion valve, evaporator and working fluid in a fluid circuit. The mass flow is controlled using a quality sensor for the working fluid exiting the evaporator, and a high side pressure sensor. A control circuit is provided that monitors the quality sensor and the high side pressure sensor, and controls operation of the compressor, condenser fan and valve in response thereto. A flow reduction mode is used to reduce high side pressure at the valve inlet without excessive compressor cycling by changing the quality sensor set point when the high side pressure exceeds the condenser fan turn-on pressure but is less than the compressor disengage pressure.Type: GrantFiled: May 3, 1995Date of Patent: December 26, 1995Assignee: Parker-Hannifin CorporationInventors: Richard L. Kenyon, Roy M. Yabuki, Chester D. Campbell, Sandra L. Harper, Michael Nolan, Virender Jain, Alan Matthies
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Patent number: 5460349Abstract: An expansion valve (10) for heat transfer systems such as an air conditioning system, includes a control element (20) for controlling the flow rate of working fluid through the valve. The control element has a stem member (28) and movable member (42) movable on the stem member. Openings (38) to an internal passage (30) in the stem member are regulated by positioning the movable member to achieve regulated flow rate of refrigerant material through the valve. The movable member of the control element is moved by a plunger (24) of a proportional solenoid (22). The proportional solenoid has a magnetic flux circuit including a low permeance isolation tube (62) surrounding the plunger, which enables removal of the coil (76) and frame (78) of the solenoid from the valve. The solenoid further includes a variable permeance flux washer (69) the flux through which varies with plunger position, which is disposed from a gap (82) which provides an area of magnetic saturation.Type: GrantFiled: November 18, 1993Date of Patent: October 24, 1995Assignee: Parker-Hannifin CorporationInventors: Chester D. Campbell, Sandra L. Harper, Virender Jain, Richard L. Kenyon, Alan Matthies, Roger G. Riefler, Roy M. Yabuki, Ashok Zopey
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Patent number: 5390897Abstract: An expansion valve (10) for heat transfer systems such as an air conditioning system, includes a control element (20) for controlling the flow rate of working fluid through the valve. The control element has a stem member (28) and movable member (42) movable on the stem member. Openings (38) to an internal passage (30) in the stem member are regulated by positioning the movable member to achieve regulated flow rate of refrigerant material through the valve. The movable member of the control element is moved by a plunger (24) of a proportional solenoid (22). The proportional solenoid has a magnetic flux circuit including a low permeance isolation tube (62) surrounding the plunger, which enables removal of the coil (76) and frame (78) of the solenoid from the valve. The solenoid further includes a variable permeance flux washer (69) the flux through which varies with plunger position, which is disposed from a gap (82) which provides an area of magnetic saturation.Type: GrantFiled: December 3, 1993Date of Patent: February 21, 1995Assignee: Parker Hannifin CorporationInventors: Chester D. Campbell, Sandra L. Harper, Virender Jain, Richard L. Kenyon, Alan Matthies, Roger G. Riefler, Roy M. Yabuki, Ashok Zopey
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Patent number: 5335513Abstract: A heat transfer system includes a high side pressure sensor in the form of a temperature dependent resistance in heat exchange with the system working fluid to locally heat the fluid in response to a control signal. Control means are provided for applying the control signal to the resistance and detecting a minimum thermal resistance between the thermistor and the working fluid.Type: GrantFiled: January 19, 1993Date of Patent: August 9, 1994Assignee: Parker-Hannifin CorporationInventors: Chester D. Campbell, Sandra L. Harper, Virender Jain, Richard L. Kenyon, Alan Matthies, Roy M. Yabuki
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Patent number: 5295656Abstract: An expansion valve (10) for heat transfer systems such as an air conditioning system, includes a control element (20) for controlling the flow rate of working fluid through the valve. The control element has a stem member (28) and movable member (42) movable on the stem member. Openings (38) to an internal passage (30) in the stem member are regulated by positioning the movable member to achieve regulated flow rate of refrigerant material through the valve. The movable member of the control element is moved by a plunger (24) of a proportional solenoid (22). The proportional solenoid has a magnetic flux circuit including a low permeance isolation tube (62) surrounding the plunger, which enables removal of the coil (76) and frame (78) of the solenoid from the valve. The solenoid further includes a variable permeance flux washer (69) the flux through which varies with plunger position, which is disposed from a gap (82) which provides an area of magnetic saturation.Type: GrantFiled: October 15, 1992Date of Patent: March 22, 1994Assignee: Parker Hannifin CorporationInventors: Chester D. Campbell, Sandra L. Harper, Virender Jain, Richard L. Kenyon, Alan Matthies, Roger G. Riefler, Roy M. Yabuki, Ashok Zopey
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Patent number: 5289692Abstract: A mass flow control apparatus and method for use in combination with a heat transfer system having a compressor, condenser, expansion valve, evaporator and working fluid in a s fluid circuit. The mass flow is controlled using a quality sensor for the working fluid exiting the evaporator, and a high side pressure sensor. A control circuit is provided that monitors the quality sensor and the high side pressure sensor, and controls operation of the compressor, condenser fan and valve in response thereto. A flow reduction mode is used to reduce high side pressure at the valve inlet without excessive compressor cycling by changing the quality sensor setpoint when the high side pressure exceeds the condenser fan turn-on pressure but is less than the compressor disengage pressure.Type: GrantFiled: January 19, 1993Date of Patent: March 1, 1994Assignee: Parker-Hannifin CorporationInventors: Chester D. Campbell, Sandra L. Harper, Jain Virender, Richard L. Kenyon, Alan Matthies, Roy M. Yabuki