US3766834A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressostat
Assignee: Danfoss AS
•
Filing: 1972-05-24
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Granted: 1973-10-23
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Expires: 1992-05-24
Abstract
Abstract The invention is a pressostat assembly which includes two bellows, one inside the other, which have fluid communication. Both bellows are fixedly attached to a rod form of operating member and the outer bellows operates to impart a closing movement to the operating member if the inner bellows should develop a leak. The effective cross sectional area of the outer bellows is larger that that of the inner bellows.
Inventors
- 👤 A Kraemer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:32
CPC Classifications
H; H01; H01H; H01H35/00; H01H35/24; H01H35/26; H01H35/2671
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
85 words
A pressostat assembly comprising a casing forming a chamber having a fluid inlet and a fluid pressure equalizing port, a first bellows in said chamber and attached to said casing, said first bellows having an open end in surrounding relation to said port, a rod inside said first bellows attached to the opposite end thereof and extending through said port, a second bellows attached to and surrounding said casing, said second bellows having one end thereof attached to said rod in fluid tight relation thereto.
Claim 2
Dependent Claim
85 words
A pressostat assembly comprising a casing forming a chamber having a fluid inlet and a fluid pressure equalizing port, a first bellows in said chamber and attached to said casing, said first bellows having an open end in surrounding relation to said port, a rod inside said first bellows attached to the opposite end thereof and extending through said port, a second bellows attached to and surrounding said casing, said second bellows having one end thereof attached to said rod in fluid tight relation thereto.
Claim 3
Dependent Claim
20 words
A pressostat assembly according to claim 1 including spring means biasing said rod in the direction of said opposite end.
Claim 4
Dependent Claim
22 words
A pressostat assembly according to claim 1 wherein said second bellows has a larger effective cross sectional area than said first bellows.
Claim 5
Dependent Claim
21 words
A pressostat assembly according to claim 1 wherein the gaseous pressure internally of said first bellows is lower than atmospheric pressure.
References Cited (Backward Citations)
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Cited
US2297872A
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US2795239A
Cited
US2663155A
Cited
US2761927A
Cited
US3055219A
Cited
US2988282A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |