Patent US4436998A successfully refreshed from Google Patents.
US4436998A
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US
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Helium leakage detector
Assignee: Alcatel CIT SA
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Filing: 1982-12-20
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Granted: 1984-03-13
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Expires: 2002-12-20
Abstract
Abstract The invention relates to a helium leakage detector. It includes a measuring spectrometric cell (8) disposed in parallel with a molecular diffusion pump (6) whose outlet (7) is short-circuited at the inlet (5) by a pipe (10) upstream from a constriction (11) constituted by an adjustable valve.
Inventors
- 👤 Jacques Tallon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:47
CPC Classifications
G; G01; G01M; G01M3/00; G01M3/02; G01M3/04; G01M3/20; G01M3/202
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
111 words
In a helium leakage detector having no vane pump, and including a molecular diffusion pump (6) having an inlet (5) and outlet (7), and a measuring spectrometric cell connected in a branch circuit from said diffusion pump, wherein the improvement comprises a bypass conduit connecting said outlet (7) to an inlet connection to a structure to be tested, and restriction means connected between said inlet (5) of said diffusion pump (6) and said inlet connection to said structure to be tested, whereby the necessity of using a vane pump is avoided, allowing a recirculating loop of gas to be maintained within the system for some period of time for measuring purposes.
Claim 2
Dependent Claim
111 words
In a helium leakage detector having no vane pump, and including a molecular diffusion pump (6) having an inlet (5) and outlet (7), and a measuring spectrometric cell connected in a branch circuit from said diffusion pump, wherein the improvement comprises a bypass conduit connecting said outlet (7) to an inlet connection to a structure to be tested, and restriction means connected between said inlet (5) of said diffusion pump (6) and said inlet connection to said structure to be tested, whereby the necessity of using a vane pump is avoided, allowing a recirculating loop of gas to be maintained within the system for some period of time for measuring purposes.
Claim 3
Dependent Claim
14 words
The detector according to claim 1, wherein said restriction means comprises an adjustable valve.
Claim 4
Dependent Claim
16 words
The detector according to claim 1, further comprising a measuring valve disposed in said bypass conduit.
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) | 1987-03-13 | 1987-09-12 | 1988-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-13 | 1991-09-12 | 1992-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-13 | 1995-09-12 | 1996-03-13 | $7700.00 | Window Closed / Lapsed |