US3812872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System to prevent freezing of heating units such as boilers
Assignee: Raypak Inc
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Filing: 1972-06-22
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Granted: 1974-05-28
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Expires: 1992-06-22
Abstract
Abstract A control system to prevent freezing of heating units, such as boilers, particularly those which may be outdoors, such as on a rooftop. A drain valve is provided to automatically drain the water from the unit in the event of power failure which would prevent heating of the water, or in the event of the occurrence of a low temperature of the water approaching freezing, or both. The system may also include a valve which closes in response to one or both of these conditions to prevent admission of water to the unit. The drain valve embodies a time delay feature so as to not respond to power failures of minimum predetermined duration.
Inventors
- 👤 K Vodraska
- 👤 L Block
- 👤 L Ashton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:51
CPC Classifications
E; E03; E03B; E03B7/00; E03B7/09; E03B7/10; Y; Y10; Y10T; Y10T137/00; Y10T137/1189; Y10T137/1298; Y10T137/1353
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
132 words
A freeze damage prevention system for a heating unit for heating water and the like wherein said unit is situated to be subject to damage from freezing of the liquid within it, the system comprising: normally closed valve means connected to the unit in a position whereby to drain the liquid from the unit sufficiently to prevent damage from freezing in the unit; and means controlling said valve means responsive to a condition indicative of possible or imminent freezing of liquid within the unit, said responsive means comprising mechanism actuatable in response to power failure whereby to cause said normally closed valve to open, said valve means embodying a time delay mechanism whereby said valve means is prevented from opening in response to a power failure of a predetermined relatively short duration.
Claim 2
Dependent Claim
132 words
A freeze damage prevention system for a heating unit for heating water and the like wherein said unit is situated to be subject to damage from freezing of the liquid within it, the system comprising: normally closed valve means connected to the unit in a position whereby to drain the liquid from the unit sufficiently to prevent damage from freezing in the unit; and means controlling said valve means responsive to a condition indicative of possible or imminent freezing of liquid within the unit, said responsive means comprising mechanism actuatable in response to power failure whereby to cause said normally closed valve to open, said valve means embodying a time delay mechanism whereby said valve means is prevented from opening in response to a power failure of a predetermined relatively short duration.
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) | 1977-05-27 | 1977-11-26 | 1978-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-27 | 1981-11-26 | 1982-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-27 | 1985-11-26 | 1986-05-28 | $7700.00 | Window Closed / Lapsed |