Patent US4581901A successfully refreshed from Google Patents.
US4581901A
Expired / Lapsed
US
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Control system for a heat pump system
Assignee: Emerson Electric Co
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Filing: 1984-07-05
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Granted: 1986-04-15
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Expires: 2004-07-05
Abstract
Abstract A control system provides slow and fast defrost cycles for a heat pump by providing an auxiliary manual switch to select different cams of a timing means for cycle operation. Selective ones of the cam switches are connected in parallel to permit two different defrost time cycles utilizing four cams rotating at the same speed.
Inventors
- 👤 George W. Adams
- 👤 Jimmy L. Sheeks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:09
CPC Classifications
F; F25; F25D; F25D21/00; F25D21/002; F25D21/008
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
178 words
A defrost control system providing first and second defrost cycles wherein a timing means includes power driven cam means and first, second, third and fourth electrical switches opening and closing in response to said cam means, said first and fourth electrical switches adapted to be selectively electrically coupled to a relay and a temperature control means of a heat pump, and a manual selector switch adapted to be electrically coupled to selected ones of said first, second, third and fourth electrical switches, and wherein said first and second defrost cycles are selectively provided as follows: for said first defrost cycle, said manual selector switch positioned to provide a parallel connection between said second and third electrical switches with said second switch being in series with said first and fourth switches; said first and fourth switches electrically coupled to said relay and said temperature control means, for said second defrost cycle, said manual switch positioned to provide a parallel connection between said first and second switches; said first switch electrically coupled to said relay and said temperature control means.
Claim 2
Dependent Claim
178 words
A defrost control system providing first and second defrost cycles wherein a timing means includes power driven cam means and first, second, third and fourth electrical switches opening and closing in response to said cam means, said first and fourth electrical switches adapted to be selectively electrically coupled to a relay and a temperature control means of a heat pump, and a manual selector switch adapted to be electrically coupled to selected ones of said first, second, third and fourth electrical switches, and wherein said first and second defrost cycles are selectively provided as follows: for said first defrost cycle, said manual selector switch positioned to provide a parallel connection between said second and third electrical switches with said second switch being in series with said first and fourth switches; said first and fourth switches electrically coupled to said relay and said temperature control means, for said second defrost cycle, said manual switch positioned to provide a parallel connection between said first and second switches; said first switch electrically coupled to said relay and said temperature control means.
Claim 3
Dependent Claim
21 words
A defrost control system according to claim 1 wherein said manual selector switch means is a double pole double throw switch.
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) | 1989-04-14 | 1989-10-14 | 1990-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-14 | 1993-10-14 | 1994-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-14 | 1997-10-14 | 1998-04-15 | $7700.00 | Window Closed / Lapsed |