US4460018A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultralow pressure relief valve
Assignee: Philip Morris USA Inc
•
Filing: 1981-06-19
•
Granted: 1984-07-17
•
Expires: 2001-06-19
Abstract
Abstract An ultralow pressure relief valve (10) is disclosed. Sealing fluid (24) is held in place by capillary forces inside capillary tube (12). When pressure in tube (11) exceeds capillary forces, sealing fluid (24) is forced into reservoir (14), protecting pressure gage (20) from overpressurization.
Inventors
- 👤 William R. Sweeney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:46
CPC Classifications
G; G01; G01L; G01L19/00; G01L19/06; G01L19/0618; Y; Y10; Y10T; Y10T137/00; Y10T137/206; Y10T137/2065; Y10T137/2082; Y10T137/4456; Y10T137/4643
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
76 words
An ultralow pressure relief valve comprising: a pressure responsive means connected to an area of high pressure; a capillary tube connecting the area of high pressure and an area of low pressure; a sealing fluid contained in said capillary tube and capable of sealing said tube by capillary attraction against low differential pressures; a reservoir on the low pressure side of said capillary tube; and a capillary wire extending from said reservoir to said capillary tube.
Claim 2
Dependent Claim
76 words
An ultralow pressure relief valve comprising: a pressure responsive means connected to an area of high pressure; a capillary tube connecting the area of high pressure and an area of low pressure; a sealing fluid contained in said capillary tube and capable of sealing said tube by capillary attraction against low differential pressures; a reservoir on the low pressure side of said capillary tube; and a capillary wire extending from said reservoir to said capillary tube.
Claim 3
Dependent Claim
29 words
An ultralow pressure relief valve as in claim 1 wherein said capillary tube has a reservoir on the low pressure side and a reservoir on the high pressure side.
Claim 4
Dependent Claim
61 words
A high volume ultralow pressure relief valve comprising: a pressure wall separating a first pressure region and a second pressure region; a reservoir located below said pressure wall; a sealing fluid contained in said reservoir and capable of sealing said reservoir by capillary attraction against low differential pressures; and capillary fingers attached to said pressure wall extending into said sealing fluid.
Claim 5
Dependent Claim
61 words
A high volume ultralow pressure relief valve comprising: a pressure wall separating a first pressure region and a second pressure region; a reservoir located below said pressure wall; a sealing fluid contained in said reservoir and capable of sealing said reservoir by capillary attraction against low differential pressures; and capillary fingers attached to said pressure wall extending into said sealing fluid.
Claim 6
Dependent Claim
42 words
An ultralow pressure relief valve as in claim 1 wherein said sealing fluid is a magnetic fluid capable of sealing said capillary tube by capillary attraction against low differential pressures and wherein magnets are disposed on opposite sides of said capillary tube.
Claim 7
Dependent Claim
15 words
An ultralow pressure relief valve as in claim 4 wherein said magnets are permanent magnets.
Claim 8
Dependent Claim
13 words
An ultralow pressure relief as in claim 5 wherein said magnets are electromagnets.
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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) | 1987-07-17 | 1988-01-16 | 1988-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-17 | 1992-01-16 | 1992-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-17 | 1996-01-16 | 1996-07-17 | $7700.00 | Window Closed / Lapsed |