US3867631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Leak detection apparatus and inlet interface
Assignee: Varian Medical Systems Inc
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Filing: 1974-02-14
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Granted: 1975-02-18
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Expires: 1994-02-14
Abstract
Abstract A leak detection apparatus having a mass spectrometer tuned to detect helium has an interface with atmosphere in the form of a portable probe containing a gas inlet membrane which is operable without a heater to permit the passage of helium in sufficient quantity for sensitive detection of leaks.
Inventors
- 👤 Walton E Briggs
- 👤 Joseph C Maliakal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:54
CPC Classifications
G; G01; G01M; G01M3/00; G01M3/02; G01M3/04; G01M3/20; G01M3/202; G01M3/205; H; H01; H01J; H01J49/00; H01J49/02; H01J49/04; H01J49/0422; H01J49/0427
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
81 words
A VACUUM LEAK DETECTION SYSTEM FOR DETECTING THE PRESENCE OF A LEAK-INDICATIVE HELIUM GAS SIGNAL IN AN ATMOSPHERE, SAID SYSTEM COMPRISING A MASS SPECTROMETER CAPABLE OF DETECTING HELIUM GAS, MEANS FORMING A GAS INLET PASSAGE TO SAID MASS SPECTROMETER, MEMBRANE MEANS CAPABLE OF ADMITTING HELIUM GAS THERETHROUGH PREFERENTIALLY WITH RESPECT TO OTHER GASES IN THE ATMOSPHERE, SAID MEMBRANE MEANS COMPRISING A SOLID ONE-PIECE POLYTETRAFLUOROETHYLENE MEMBRANE SEALED ACROSS SAID INLET PASSAGE TO FORM AN INTERFACE BETWEEN SAID INLET PASSAGE AND THE ATMOSPHERE.
Claim 2
Dependent Claim
81 words
A VACUUM LEAK DETECTION SYSTEM FOR DETECTING THE PRESENCE OF A LEAK-INDICATIVE HELIUM GAS SIGNAL IN AN ATMOSPHERE, SAID SYSTEM COMPRISING A MASS SPECTROMETER CAPABLE OF DETECTING HELIUM GAS, MEANS FORMING A GAS INLET PASSAGE TO SAID MASS SPECTROMETER, MEMBRANE MEANS CAPABLE OF ADMITTING HELIUM GAS THERETHROUGH PREFERENTIALLY WITH RESPECT TO OTHER GASES IN THE ATMOSPHERE, SAID MEMBRANE MEANS COMPRISING A SOLID ONE-PIECE POLYTETRAFLUOROETHYLENE MEMBRANE SEALED ACROSS SAID INLET PASSAGE TO FORM AN INTERFACE BETWEEN SAID INLET PASSAGE AND THE ATMOSPHERE.
Claim 3
Dependent Claim
131 words
The system of claim 1 wherein said means forming said gas inlet passage comprises a member having a surface portion which faces said membrane, said surface portion having an annular recess, and wherein said means for sealing said membrane across said inlet passage comprises a first sealing ring disposed within said annular recess in contact with an annular portion of one side of said membrane, a second sealing ring disposed in contact with an annular portion of the other side of said membrane, and an annular cap which is press-fitted over said means forming said gas inlet passage such that said first sealing ring is compressed against said annular portion of said one side of said membrane and said second sealing ring is compressed against said other side of said membrane.
Claim 4
Dependent Claim
47 words
The system of claim 2 wherein said means forming said gas inlet passage comprises a tubular body member and a tubular probe head member, said probe head member being received within said body member, said probe head member having said recessed surface portion which faces said membrane.
Claim 5
Dependent Claim
25 words
The system of claim 2 wherein said first and second sealing rings are located in alignment with each other on opposite sides of said membrane.
Claim 6
Dependent Claim
22 words
The system of claim 2 wherein said first sealing ring is an O-ring and said second sealing ring is a quad ring.
Claim 7
Dependent Claim
103 words
The system of claim 2 wherein one of said sealing rings is an O-ring and the other of said sealing rings is a quad ring, and wherein said sealing rings are positioned in alignment with each other on opposite sides of said membrane such that press-fitting of said cap over said means forming said gas inlet passage causes the annular portion of said membrane in contact with said O-ring to acquire a concave contour with respect to said O-ring and the annular portion of said membrane in contact with said quad ring to acquire a convex contour with respect to said quad ring.
Claim 8
Dependent Claim
22 words
The system of claim 6 wherein said first sealing ring is the O-ring and said second sealing ring is the quad ring.
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) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |