US3797805A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealing means for a valve stem
Assignee: Danfoss AS
•
Filing: 1972-09-25
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Granted: 1974-03-19
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Expires: 1992-09-25
Abstract
Abstract The invention relates to a thermostatic valve assembly for controlling the flow of a liquid therethrough. The assembly has a secondary seal for its valve stem which is made of a material which expands when contacted by a leaking quantity of the liquid being controlled. The expansion of the seal inhibits the leakage and the movement of the valve closure member. This manifestation of malfunctioning is a signal that the primary seal has become defective.
Inventors
- 👤 H Nielsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:46
CPC Classifications
F; F16; F16K; F16K41/00; F16K41/02; F16K41/04; Y; Y10; Y10S; Y10S285/00; Y10S285/925; Y10T; Y10T137/00; Y10T137/1624
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
106 words
A valve assembly comprising a casing, a first bushing attached to said casing and having a bore, a closure member having a shaft portion disposed in said bore, a second bushing attached to said first bushiNg and having a bore, a rod slidably disposed in said second bushing bore and having contact with said shaft, a primary and secondary seals between said rod and said second bushing, said secondary seal being of a material which increases in volume upon contact with the medium to be sealed, said secondary seal being fitted that upon its volume being increased exerts forces which inhibit the displacement of said rod.
Claim 2
Dependent Claim
106 words
A valve assembly comprising a casing, a first bushing attached to said casing and having a bore, a closure member having a shaft portion disposed in said bore, a second bushing attached to said first bushiNg and having a bore, a rod slidably disposed in said second bushing bore and having contact with said shaft, a primary and secondary seals between said rod and said second bushing, said secondary seal being of a material which increases in volume upon contact with the medium to be sealed, said secondary seal being fitted that upon its volume being increased exerts forces which inhibit the displacement of said rod.
Claim 3
Dependent Claim
19 words
A valve assembly according to claim 1 including a return spring for moving said rod in an opening direction.
Claim 4
Dependent Claim
20 words
A valve assembly according to claim 1 wherein said secondary seal loosely surrounds said rod when in a dry condition.
Claim 5
Dependent Claim
15 words
A valve assembly according to claim 1 wherein said secondary seal is made of leather.
Claim 6
Dependent Claim
16 words
A valve assembly according to claim 1 wherein said secondary seal is made of hydrate cellulose.
Claim 7
Dependent Claim
16 words
A valve assembly according to claim 1 wherein said secondary seal comprises a plurality of disks.
Claim 8
Dependent Claim
20 words
A valve assembly according to claim 1 wherein said secondary seal comprises a coil of material wound around said rod.
References Cited (Backward Citations)
US672255A
Cited
US2277286A
Cited
US2810592A
Cited
US2945541A
Cited
US2849070A
Cited
US3490735A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |