David P Bagshaw

US Patent:

44508689, May 29, 1984

Filed:

Apr 30, 1981

Appl. No.:

6/258966

Inventors:

Eugene F. Duval - Palo Alto CA
David P. Bagshaw - Stanford CA
Michael A. Kast - Menlo Park CA
Gilbert M. Masters - Menlo Park CA
Harry T. Whitehouse - Menlo Park CA

International Classification:

F16K 1106

US Classification:

13762529

Abstract:

A freeze protection system allows the working fluid contained in the communicating tubes of the solar collector to drain from both the input and output tubes of the collector when a first predetermined temperature of the working fluid is detected and to fill the collector via both the input and output tubes when a second predetermined temperature is detected. The invention includes valve mechanisms, of the spool valve variety, that communicate the working fluid to be heated to the collector and therefrom to a storage tank, a valve actuator and a sensor. The actuator moves a valve element from a first position for communicating working fluid to be heated from a source to the input tube of the collector and for communicating heated working fluid from the output tube of the collector to a storage facility to a second position for interrupting fluid communication from the source to the collector and for communicating both the input and output tubes of the collector to a drainpipe--draining the collector of working fluid--when the first predetermined temperature level is detected by the sensor. Upon detection of the second predetermined temperature level the sensor causes the actuator to return the valve element to the first position via an intermediate position that closes the drainpipe and temporarily communicates the working fluid to both the input and output tubes of the collector.

US Patent:

43958826, Aug 2, 1983

Filed:

Feb 20, 1981

Appl. No.:

6/236096

Inventors:

Michael A. Kast - Menlo Park CA
David P. Bagshaw - Redwood City CA
Harry T. Whitehouse - Redwood City CA

Assignee:

Sunspool Corporation - Palo Alto CA

International Classification:

F03G 706

US Classification:

60527

Abstract:

A support member is used to mount a heat motor and at least one electrical resistance heating element for actuating said heat motor. The support member is made of a thermally conductive material with cylindrical openings which receive the motor and heating element(s). Heat from the resistance element actuates the motor by heat conductance through the support.

US Patent:

45414122, Sep 17, 1985

Filed:

Feb 16, 1983

Appl. No.:

6/466818

Inventors:

David P. Bagshaw - Redwood City CA
Michael A. Kast - Menlo Park CA
Harry T. Whitehouse - Redwood City CA

Assignee:

Sunspool Corporation - Menlo Park CA

International Classification:

F24J 302
F16K 1504

US Classification:

126419

Abstract:

A freeze protection system allows the working fluid contained in the communicating tubes of the solar collector to drain from both the input and output tubes of the collector when a first predetermined temperature of the working fluid is detected and to fill the collector via both the input and output tubes when a second predetermined temperature is detected. The invention includes valve mechanism, of the spool valve variety, that communicate the working fluid to be heated to the collector and therefrom to a storage tank, a valve actuator and a sensor. The actuator moves a valve element from a first position for communicating working fluid to be heated from a source to the input tube of the collector and for communicating heated working fluid from the output tube of the collector to a storage facility to a second position for interrupting fluid communication from the source to the collector and for communicating both the input and output tubes of the collector to a drainpipe--draining the collector of working fluid--when the first predetermined temperature level is detected by the sensor. Upon detection of the second predetermined temperature level the sensor causes the actuator to return the valve element to the first position via an intermediate position that closes the drainpipe and temporarily communicates the working fluid to both the input and output tubes of the collector. As part of the invention, a unique holder of a thermally conductive material is provided to hold the power and heater parts of the actuator.

US Patent:

42804787, Jul 28, 1981

Filed:

Nov 13, 1978

Appl. No.:

5/960399

Inventors:

Eugene F. Duval - Palo Alto CA
David P. Bagshaw - Stanford CA
Michael A. Kast - Menlo Park CA
Gilbert M. Masters - Menlo Park CA
Harry T. Whitehouse - Menlo Park CA

International Classification:

F24J 302

US Classification:

126420

Abstract:

A freeze protection system allows the working fluid contained in the communicating tubes of the solar collector to drain from both the input and output tubes of the collector when a first predetermined temperature of the working fluid is detected and to fill the collector via both the input and output tubes when a second predetermined temperature is detected. The invention includes valve mechanisms, of the spool valve variety, that communicate the working fluid to be heated to the collector and therefrom to a storage tank, a valve actuator and a sensor. The actuator moves a valve element from a first position for communicating working fluid to be heated from a source to the input tube of the collector and for communicating heated working fluid from the output tube of the collector to a storage facility to a second position for interrupting fluid communication from the source to the collector and for communicating both the input and output tubes of the collector to a drainpipe--draining the collector of working fluid--when the first predetermined temperature level is detected by the sensor. Upon detection of the second predetermined temperature level the sensor causes the actuator to return the valve element to the first position via an intermediate position that closes the drainpipe and temporarily communicates the working fluid to both the input and output tubes of the collector.