US4745765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
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 09:23
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)
US2621487A
Cited
US3047696A
Cited
US3303663A
Cited
US3400552A
Cited
US3729949A
Cited
US4106306A
Cited
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 |