US3791161A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure switch for refrigeration system
Assignee: Ardco Inc
•
Filing: 1972-04-10
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Granted: 1974-02-12
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Expires: 1992-04-10
Abstract
Abstract A pressure switch for sensing and responding to pressure on the low side of refrigeration systems where the conduit, which connects the refrigeration system low side to the pressure switch bellows, is restricted for the purpose of minimizing transmission of pressure pulsations from the low side to the bellows. The conduit has a substantial enlargement positioned to act to prevent the entry of oil into the restricted portion of the conduit.
Inventors
- 👤 D Kramer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:03
CPC Classifications
F; F25; F25B; F25B49/00; F25B49/02; F25B49/025; F25B2700/00; F25B2700/19; F25B2700/193; F25B2700/1933
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
100 words
In a refrigeration system of the compression type having a high pressure side and a low pressure side including a conduit connected compressor, condenser, expansion device and evaporator and a pressure switch having a pressure sensing element including fixed restricted means for pressure communication to the element the improvement comprising a chamber having first and second ports where the first port is unrestrictedly connected to the low pressure side and the second port is connected to the means whereby oil circulated by the compressor through the system is allowed to enter the chamber and is prevented fRom entering the means.
Claim 2
Dependent Claim
100 words
In a refrigeration system of the compression type having a high pressure side and a low pressure side including a conduit connected compressor, condenser, expansion device and evaporator and a pressure switch having a pressure sensing element including fixed restricted means for pressure communication to the element the improvement comprising a chamber having first and second ports where the first port is unrestrictedly connected to the low pressure side and the second port is connected to the means whereby oil circulated by the compressor through the system is allowed to enter the chamber and is prevented fRom entering the means.
Claim 3
Dependent Claim
20 words
An improvement as in claim 1 where the chamber has a screen interposed between the first and the second ports.
Claim 4
Dependent Claim
58 words
In a pressure switch having fixed restricted means for connection to the low pressure side of a compression type refrigeration system having both high and low pressure sides, the improvement comprising a chamber having first and second ports where the first port is unrestrictedly connected to the low side and the second port is connected to the means.
Claim 5
Dependent Claim
58 words
In a pressure switch having fixed restricted means for connection to the low pressure side of a compression type refrigeration system having both high and low pressure sides, the improvement comprising a chamber having first and second ports where the first port is unrestrictedly connected to the low side and the second port is connected to the means.
Claim 6
Dependent Claim
19 words
An improvement as in claim 3 where the chamber has a screen interposed between the first and second ports.
Claim 7
Dependent Claim
16 words
An improvement in pressure switches as in claim 3 where the means includes a capillary tube.
Claim 8
Dependent Claim
15 words
An improvement in pressure switches as in claim 3 where the means includes an orifice.
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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |