US4584844A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat pump
Assignee: Canadian Patents and Development Ltd
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Filing: 1984-09-04
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Granted: 1986-04-29
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Expires: 2004-09-04
Abstract
Abstract A heat pump system suitable for northern climates which utilizes a pressure limiting device that reduces pressure and capacity of the system in the cooling mode so as to allow a higher capacity in the heating mode for a given compressor-motor power rating. The pressure limiting device also alleviates problems associated with system reversal, such as for periodic outdoor heat exchanger defrosting.
Inventors
- 👤 Clayton Lemal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:59
CPC Classifications
F; F25; F25B; F25B41/00; F25B41/20; F25B41/22
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
165 words
A heat pump system for operating selectively in a heating or cooling mode and including a compressor having an inlet and outlet, an indoor and outdoor heat exchanger, a four-way reversing valve, and a pressure reducing metering device, for use in climates requiring a higher capacity in the heating mode than in the cooling mode, said system comprising a pressure limited device serially connected to the inlet of the compressor, said pressure limiting device comprising pressure responsive means for restricting refrigerant flow as pressure increases and shutting off flow at a predetermined pressure to define a maximum pressure limit, said maximum pressure limit being selected to fall within a predetermined operating pressure range of the system encountered in the heating mode but less that the operating pressures encountered in the cooling mode whereby refrigerant flow, pressure and capacity are reduced for all operation in the cooling mode and whereby the pressure and capacity are unaffected in a lower ambient temperature range of the heating mode.
Claim 2
Dependent Claim
165 words
A heat pump system for operating selectively in a heating or cooling mode and including a compressor having an inlet and outlet, an indoor and outdoor heat exchanger, a four-way reversing valve, and a pressure reducing metering device, for use in climates requiring a higher capacity in the heating mode than in the cooling mode, said system comprising a pressure limited device serially connected to the inlet of the compressor, said pressure limiting device comprising pressure responsive means for restricting refrigerant flow as pressure increases and shutting off flow at a predetermined pressure to define a maximum pressure limit, said maximum pressure limit being selected to fall within a predetermined operating pressure range of the system encountered in the heating mode but less that the operating pressures encountered in the cooling mode whereby refrigerant flow, pressure and capacity are reduced for all operation in the cooling mode and whereby the pressure and capacity are unaffected in a lower ambient temperature range of the heating mode.
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) | 1989-04-28 | 1989-10-28 | 1990-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-28 | 1993-10-28 | 1994-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-28 | 1997-10-28 | 1998-04-29 | $7700.00 | Window Closed / Lapsed |