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US4745765A
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Low refrigerant charge detecting device
Assignee: Motors Liquidation Co
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Filing: 1987-05-11
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Granted: 1988-05-24
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Expires: 2007-05-11
Abstract
Abstract A low refrigerant charge detecting device comprises a refrigerant superheat temperature transducer that senses refrigerant leaving the evaporator and provides a positional output indicative of the superheat temperature of the sensed refrigerant, an ambient air temperature transducer that senses ambient air and provides a positional output indicative of the ambient air temperature, and a low charge signal effecter that responds to both the positional outputs and provides a low charge signal at predetermined refrigerant superheat and ambient air temperatures.
Inventors
- 👤 Edward D. Pettitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:40
CPC Classifications
B; B60; B60H; B60H1/00; B60H1/00507; B60H1/00585; B60H1/32; B60H1/3204; B60H1/3225; F; F25; F25B; F25B49/00; F25B49/005; F25B2500/00; F25B2500/22; F25B2500/222; F25B2700/00; F25B2700/21; F25B2700/2106
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
112 words
In an air conditioning system charged with a refrigerant whose amount may diminish in time, said system including a evaporator, an improved low refrigerant charge detecting device comprising a sealed bellows containing refrigerant having a stationary end and an extendible end, said extendible end supporting an electrical contact and formed with a protruding temperature probe portion exposed to the refrigerant leaving the evaporator, an open bellows having a stationary end open to the refrigerant leaving the evaporator and an extendible end fixed to the extendible end of said sealed bellows about said probe portion, and a bimetal element exposed to ambient air supporting an electrical contact located opposite said first mentioned contact.
Claim 2
Dependent Claim
112 words
In an air conditioning system charged with a refrigerant whose amount may diminish in time, said system including a evaporator, an improved low refrigerant charge detecting device comprising a sealed bellows containing refrigerant having a stationary end and an extendible end, said extendible end supporting an electrical contact and formed with a protruding temperature probe portion exposed to the refrigerant leaving the evaporator, an open bellows having a stationary end open to the refrigerant leaving the evaporator and an extendible end fixed to the extendible end of said sealed bellows about said probe portion, and a bimetal element exposed to ambient air supporting an electrical contact located opposite said first mentioned contact.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |