US3918477A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Backflow preventing device
Assignee: WILKINS-REGULATOR DIVISION OF ZURN INDUSTRIES Inc A PA CORP
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Filing: 1974-09-03
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Granted: 1975-11-11
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Expires: 1994-09-03
Abstract
Abstract A backflow preventing device having an inlet port, an outlet port and a vacuum breaker port, the vacuum breaker port having an annular valve seat engaged by a valve element having a radially inner seal ring, and a radially outer compression ring of greater height than the inner ring and having a vent opening, the rings being joined by a web and formed of elastomeric material whereby, on application of a force urging the inner ring into sealing engagement with the valve seat, the outer ring is axially compressed as well as radially deflected to exert an opposing force tending to disengage the inner ring from its valve seat and to produce a wiping action on the confronting seat so as to insure against sticking.
Inventors
- 👤 Guenter A Grams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:15
CPC Classifications
F; F16; F16K; F16K17/00; F16K15/00; F16K15/02; F16K15/06; F16K24/00; Y; Y10; Y10T; Y10T137/00; Y10T137/3149; Y10T137/3185; Y10T137/3294; Y10T137/3331; Y10T137/4238; Y10T137/4245; Y10T137/4273
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
140 words
A backflow preventing device, comprising: a. a housing structure defining a valve chamber having an inlet port, an outlet port, and an access opening; b. an inlet valve for the inlet port; c. a vent disk fitting the access opening and having a vent opening; d. a vent valve for closing the vent opening in response to positive pressure in the valve chamber; e. means connecting the inlet valve and vent valve for movement in unison during closure of the vent valve; f. and ported yieldable means integral with the vent valve, for removal and replacement as a unit therewith, projecting axially therebeyond for engaging the vent disk during closing and opening the vent valve to permit reduced flow across the vent valve immediately prior to seating of the vent valve and immediately subsequent to opening of the vent valve.
Claim 2
Dependent Claim
140 words
A backflow preventing device, comprising: a. a housing structure defining a valve chamber having an inlet port, an outlet port, and an access opening; b. an inlet valve for the inlet port; c. a vent disk fitting the access opening and having a vent opening; d. a vent valve for closing the vent opening in response to positive pressure in the valve chamber; e. means connecting the inlet valve and vent valve for movement in unison during closure of the vent valve; f. and ported yieldable means integral with the vent valve, for removal and replacement as a unit therewith, projecting axially therebeyond for engaging the vent disk during closing and opening the vent valve to permit reduced flow across the vent valve immediately prior to seating of the vent valve and immediately subsequent to opening of the vent valve.
Claim 3
Dependent Claim
149 words
A backflow preventing device as defined in claim 1, wherein: a. the yieldable means is a ring disposed in radial relation to the vent valve and having at least one notch forming said port to avoid sealing contact with the vent disk and provide said reduced flow. b. a vent valve ring supported on the disk for sealingly engaging said peripheral seat upon opening of the inlet valve; c. and a thrust element integral with the vent valve ring for removal or replacement therewith as a unit, the thrust element projecting axially beyond the vent valve ring and including a restricted means for nonsealing engageable with the housing structure in the vicinity of the vent opening for limited flow through the vent opening, the thrust element being yieldable to a predetermined positive pressure in the valve chamber to permit closure of the vent opening by the vent valve ring.
Claim 4
Dependent Claim
67 words
A backflow preventing device as defined in claim 1, wherein: a. the yieldable means includes a ring essentially concentric with respect to the vent valve and a web joining the vent valve and ring, the web and ring being distortable to produce a wiping movement with respect to the vent disk during final approach and initial recession of the vent valve with respect to the vent disk.
Claim 5
Dependent Claim
57 words
The combination with a backflow preventing device including a housing structure defining a valve chamber having an inlet port, outlet port and a vent opening provided with a peripheral seat, an inlet valve for the inlet port, of a vent valve means comprising: a. a supporting disk connected to the inlet valve for movement in unison therewith;
Claim 6
Dependent Claim
57 words
The combination with a backflow preventing device including a housing structure defining a valve chamber having an inlet port, outlet port and a vent opening provided with a peripheral seat, an inlet valve for the inlet port, of a vent valve means comprising: a. a supporting disk connected to the inlet valve for movement in unison therewith;
Claim 7
Dependent Claim
39 words
A vent valve means as defined in claim 4, wherein: a. the yieldable thrust element is a ring disposed in radial relation to the vent valve ring and said restricted means is a notch to effect non-sealing engagement therewith.
Claim 8
Dependent Claim
74 words
A vent valve means as defined in claim 4, wherein: a. the yieldable thrust element is a ring surrounding the vent valve ring and is joined thereto by a yieldable web, the web being angularly flexible to cause radial expansion and contraction of the thrust element as the vent valve ring approaches toward or receeds from sealing contact with said peripheral seat to produce a wiping contact with a wall of the valve chamber.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |