US4053725A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure switch for outdoor refrigeration systems
Assignee: Ardco Inc
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Filing: 1976-04-07
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Granted: 1977-10-11
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Expires: 1996-04-07
Abstract
Abstract A pressure switch for use in refrigeration systems which includes a restrictor to minimize the effect of compressor pulsations on the pressure sensing element and a heater positioned to warm the interior of the switch housing and to maintain the fluidity of refrigeration oil traversing the restrictor under conditions when the switch is exposed to low ambient temperatures.
Inventors
- 👤 Daniel E. Kramer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:02
CPC Classifications
F; F25; F25B; F25B49/00; F25B49/02; H; H01; H01H; H01H35/00; H01H35/24
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
62 words
Improved pressure control means comprising a casing, a switch within the casing, pressure responsive means within the casing for actuating the switch during summer and winter conditions; a connection; restricted conduit means joining the pressure responsive means to the connection for communicating pressure from the connection to the pressure responsive means; wherein the improvement comprises; heating means for warming said restricted means.
Claim 2
Dependent Claim
62 words
Improved pressure control means comprising a casing, a switch within the casing, pressure responsive means within the casing for actuating the switch during summer and winter conditions; a connection; restricted conduit means joining the pressure responsive means to the connection for communicating pressure from the connection to the pressure responsive means; wherein the improvement comprises; heating means for warming said restricted means.
Claim 3
Dependent Claim
26 words
Pressure control means as in claim 1 which includes thermostat means connected to the heating means for preventing the heating means from overheating the restricted means.
Claim 4
Dependent Claim
15 words
Pressure control means as in claim 2 where the thermostat means is within the casing.
Claim 5
Dependent Claim
15 words
Pressure control means as in claim 2 where the thermostat means is without the casing.
Claim 6
Dependent Claim
15 words
Pressure control means as in claim 1 where the heating means is within the casing.
Claim 7
Dependent Claim
15 words
Pressure control means as in claim 1 where the heating means is without the casing.
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) | 1980-10-10 | 1981-04-11 | 1981-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-10 | 1985-04-11 | 1985-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-10 | 1989-04-11 | 1989-10-11 | $7700.00 | Window Closed / Lapsed |