Patent US4418723A successfully refreshed from Google Patents.
US4418723A
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US
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Flow restrictor
Assignee: Citizen Watch Co Ltd
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Filing: 1981-08-03
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Granted: 1983-12-06
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Expires: 2001-08-03
Abstract
Abstract Improvements in a flow restrictor for use in a flowmeter measuring a flow rate according to the pressure drop caused by laminar flow, utilizing the fact that the pressure drop is proportional to the flow rate. The flow restrictor comprises a cylindrical member, and a housing having a fluid inlet and a fluid outlet for accommodating the cylindrical member, wherein at least one groove or spiral groove for passing fluid is formed in the peripheral direction of the cylindrical surface of the cylindrical member or in the peripheral direction of the inner surface of the housing forming a cylindrical cavity for accommodating the cylindrical member.
Inventors
- 👤 Tsuyoshi Koni
- 👤 Yoshihisa Urushida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:49
CPC Classifications
F; F16; F16K; F16K47/00; F16K47/08; F16K47/12; G; G01; G01F; G01F1/00; G01F1/05; G01F1/34; G01F1/36; G01F1/40
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
116 words
A flow restricter for use in a flowmeter utilizing pressure drop caused by laminar flow comprising a cylindrical member, and a housing having a fluid inlet and a fluid outlet for accommodating said cylindrical member comprising at least one groove disposed spriral in the peripheral direction of the cylindrical surface thereof, at least one endless inlet channel, at least one endless outlet channel in the longitudinal direction thereof and end plates secured to the ends thereof, one of said plates having at least one inlet opening corresponding to said at least one endless inlet channel and the other of said plates having at least one outlet opening corresponding to said at least one endless outlet channel.
Claim 2
Dependent Claim
116 words
A flow restricter for use in a flowmeter utilizing pressure drop caused by laminar flow comprising a cylindrical member, and a housing having a fluid inlet and a fluid outlet for accommodating said cylindrical member comprising at least one groove disposed spriral in the peripheral direction of the cylindrical surface thereof, at least one endless inlet channel, at least one endless outlet channel in the longitudinal direction thereof and end plates secured to the ends thereof, one of said plates having at least one inlet opening corresponding to said at least one endless inlet channel and the other of said plates having at least one outlet opening corresponding to said at least one endless outlet channel.
Claim 3
Dependent Claim
24 words
The flow restrictor according to claim 1 further comprising a sealing member, said sealing member being disposed between said cylindrical member and said housing.
Claim 4
Dependent Claim
22 words
The flow restrictor according to claim 2 wherein said sealing member is made of an elastic material such as rubber and plastics.
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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) | 1986-12-05 | 1987-06-06 | 1987-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-05 | 1991-06-06 | 1991-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-05 | 1995-06-06 | 1995-12-06 | $7700.00 | Window Closed / Lapsed |