US3702065A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automobile air conditioning compressor superheat safety and ambient switch
Assignee: Motors Liquidation Co
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Filing: 1971-08-06
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Granted: 1972-11-07
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Expires: 1991-08-06
Abstract
Abstract In preferred form, a combination ambient temperature sensing switch and refrigerant superheat temperature responsive switch for an automobile air conditioning system having an electromagnetic clutch for transmitting engine rotation to a refrigerant compressor. The ambient temperature sensing portion of the switch is connected between the automobile battery and the coil of the clutch for energizing the coil whenever ambient temperatures are above a predetermined level. The refrigerant temperature responsive portion of the switch is connected between the battery and a fuse in short-circuit relation to the clutch coil to cause the fuse to blow in response to a predetermined maximum refrigerant temperature which closes the switch. A thermistor in circuit with the refrigerant temperature responsive switch delays the short circuiting of the clutch coil to prevent immediate blowing the the fuse.
Inventors
- 👤 James W Jacobs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:46
CPC Classifications
B; B60; B60H; B60H1/00; B60H1/32; B60H1/3204; B60H1/3225; F; F25; F25B; F25B49/00; F25B49/005; F25B2327/00; F25B2327/10; F25B2327/12; F25B2700/00; F25B2700/21; F25B2700/2106; F25B2700/2115; F25B2700/21151
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
214 words
A combination ambient air temperature and refrigerant temperature and pressure control for an automobile air conditioning system comprising: a compressor having an inlet; clutch means including an electrically responsive coil for transmitting power from the automobile engine to said compressor When the clutch coil is energized; a coil energization circuit including a battery and a fuse; ambient air temperature responsive switch means in said energization circuit which operates above a predetermined ambient air temperature to energize said coil; a refrigerant temperature and pressure responsive switch having a thermal bulb and a pressure responsive casing in fluid contact with refrigerant in the inlet of said compressor; said temperature and pressure responsive switch having a pair of contacts controlled by said casing adapted to close in response to predetermined refrigerant temperatures and pressures; means including said refrigerant responsive switch and a thermistor defining a ground circuit from said fuse in shunt relationship to said clutch coil; said thermistor having an initial high resistance upon closure of said pair of contacts to delay short circuiting of said fuse whereby transient high temperatures and low pressures of refrigerant will not deactivate said clutch coil; said thermistor having a reduced resistance following the delay to cause a large current to pass through said fuse to cause it to blow.
Claim 2
Dependent Claim
214 words
A combination ambient air temperature and refrigerant temperature and pressure control for an automobile air conditioning system comprising: a compressor having an inlet; clutch means including an electrically responsive coil for transmitting power from the automobile engine to said compressor When the clutch coil is energized; a coil energization circuit including a battery and a fuse; ambient air temperature responsive switch means in said energization circuit which operates above a predetermined ambient air temperature to energize said coil; a refrigerant temperature and pressure responsive switch having a thermal bulb and a pressure responsive casing in fluid contact with refrigerant in the inlet of said compressor; said temperature and pressure responsive switch having a pair of contacts controlled by said casing adapted to close in response to predetermined refrigerant temperatures and pressures; means including said refrigerant responsive switch and a thermistor defining a ground circuit from said fuse in shunt relationship to said clutch coil; said thermistor having an initial high resistance upon closure of said pair of contacts to delay short circuiting of said fuse whereby transient high temperatures and low pressures of refrigerant will not deactivate said clutch coil; said thermistor having a reduced resistance following the delay to cause a large current to pass through said fuse to cause it to blow.
Claim 3
Dependent Claim
238 words
A combination ambient air temperature and refrigerant temperature and pressure control for an automobile air conditioning system comprising: a compressor having an inlet; clutch means including an electrically responsive coil for transmitting power from the automobile engine to said compressor when said coil is energized; a coil energization circuit having a battery and a fuse; an ambient air temperature responsive switch in said energization circuit which operates above a predetermined ambient air temperature to energize said coil; a refrigerant temperature and pressure responsive switch in fluid contact with refrigerant in the inlet of said compressor adapted to close in response to predetermined refrigerant temperatures and pressures; said switches having circular discs in spaced relation to one another with their peripheral edges joined and with the space therebetween filled with refrigerant; one of each pair of spaced discs being fixedly supported by a switch housing; movable contacts on the other of each pair of spaced discs; fixed contacts supported by said switch housing in spaced relation to said movable contacts when said switches are open; means including said refrigerant responsive switch and a thermistor in circuit with said battery and said fuse to bypass the clutch coil and short circuit said fuse when said contacts of said refrigerant responsive switch are closed; said thermistor operating to delay short circuiting of said fuse whereby temporary increases in refrigerant temperature and temporary decreases in refrigerant pressure will not de-energize said compressor.
Claim 4
Dependent Claim
238 words
A combination ambient air temperature and refrigerant temperature and pressure control for an automobile air conditioning system comprising: a compressor having an inlet; clutch means including an electrically responsive coil for transmitting power from the automobile engine to said compressor when said coil is energized; a coil energization circuit having a battery and a fuse; an ambient air temperature responsive switch in said energization circuit which operates above a predetermined ambient air temperature to energize said coil; a refrigerant temperature and pressure responsive switch in fluid contact with refrigerant in the inlet of said compressor adapted to close in response to predetermined refrigerant temperatures and pressures; said switches having circular discs in spaced relation to one another with their peripheral edges joined and with the space therebetween filled with refrigerant; one of each pair of spaced discs being fixedly supported by a switch housing; movable contacts on the other of each pair of spaced discs; fixed contacts supported by said switch housing in spaced relation to said movable contacts when said switches are open; means including said refrigerant responsive switch and a thermistor in circuit with said battery and said fuse to bypass the clutch coil and short circuit said fuse when said contacts of said refrigerant responsive switch are closed; said thermistor operating to delay short circuiting of said fuse whereby temporary increases in refrigerant temperature and temporary decreases in refrigerant pressure will not de-energize said compressor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-07 | 1976-05-08 | 1976-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-07 | 1980-05-08 | 1980-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-07 | 1984-05-08 | 1984-11-07 | $7700.00 | Window Closed / Lapsed |