US3729949A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refrigerant charging control unit
Assignee: Individual
•
Filing: 1971-12-06
•
Granted: 1973-05-01
•
Expires: 1991-12-06
Abstract
Abstract Movable switch elements responsive to temperature and pressure control the operation of a refrigerant charge unit during charging.
Inventors
- 👤 J Talbot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:03
CPC Classifications
F; F25; F25B; F25B45/00; F25B2345/00; F25B2345/001; F25B2345/004
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
107 words
Apparatus for monitoring the charge of a refrigeration system comprising a control valve for controlling the flow of refrigerant into the system, and means for controlling the operation of the control valve by sensing pressure and temperature, said means comprising an expansible device connected to the head pressure, an expansible device connected to the suction pressure of the system, and an expansible device connected to the ambient air sensing system, and switch contact elements physically connected to each of said expansible devices and positioned in relation to each other to make or not make electrical contact in accordance with pressure and ambient air temperature in the system.
Claim 2
Dependent Claim
107 words
Apparatus for monitoring the charge of a refrigeration system comprising a control valve for controlling the flow of refrigerant into the system, and means for controlling the operation of the control valve by sensing pressure and temperature, said means comprising an expansible device connected to the head pressure, an expansible device connected to the suction pressure of the system, and an expansible device connected to the ambient air sensing system, and switch contact elements physically connected to each of said expansible devices and positioned in relation to each other to make or not make electrical contact in accordance with pressure and ambient air temperature in the system.
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) | 1976-04-30 | 1976-10-30 | 1977-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-30 | 1980-10-30 | 1981-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-30 | 1984-10-30 | 1985-05-01 | $7700.00 | Window Closed / Lapsed |