Patent US3878715A successfully refreshed from Google Patents.
US3878715A
Expired / Lapsed
US
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Vortex-type flowmeter
Assignee: Yokogawa Electric Corp
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Filing: 1973-11-12
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Granted: 1975-04-22
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Expires: 1993-11-12
Abstract
Abstract A flowmeter having no moving parts and including a vortex shedder mounted transversely in a conduit forming a passage for the fluid being measured. The shedder is provided with an axially-extending gap perpendicular to the direction of fluid flow in the conduit, and means to establish a magnetic field in the gap whose lines of flux are parallel to the direction of flow. Fluid oscillations produced in the gap as a result of Karman vortices are detected on the induction principle by a pair of electrodes mounted on said shedder at axially-spaced positions within said gap. The frequency of the signal developed at the electrodes is proportional to the flow rate or flow velocity and is undisturbed by common mode flow noise.
Inventors
- 👤 Tamotsu Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:28
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/05; G01F1/20; G01F1/32; G01F1/325; G01F1/56; G01F1/58; G01P; G01P5/00; G01P5/01
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
108 words
A flowmeter of the vortex type comprising: A. a flow conduit forming a passage for the fluid to be measured; B. a vortex shedder mounted in said conduit transversely with respect to the direction of fluid flow, said shedder having an axially-extending gap at right angles to said direction of flow; C. permanent-magnet means incorporated in the body of said shedder to establish a magnetic field across said gap whose lines of flux are parallel to said direction of flow; and D. a pair of electrodes mounted on said shedder at axially-spaced positions in said gap to produce a signal whose frequency is a function of flow rate.
Claim 2
Dependent Claim
108 words
A flowmeter of the vortex type comprising: A. a flow conduit forming a passage for the fluid to be measured; B. a vortex shedder mounted in said conduit transversely with respect to the direction of fluid flow, said shedder having an axially-extending gap at right angles to said direction of flow; C. permanent-magnet means incorporated in the body of said shedder to establish a magnetic field across said gap whose lines of flux are parallel to said direction of flow; and D. a pair of electrodes mounted on said shedder at axially-spaced positions in said gap to produce a signal whose frequency is a function of flow rate.
Claim 3
Dependent Claim
108 words
A flowmeter of the vortex type comprising: A. a flow conduit forming a passage for the fluid to be measured; B. a vortex shedder mounted in said conduit transversely with respect to the direction of fluid flow, said shedder having an axially-extending gap at right angles to said direction of flow; C. permanent-magnet means incorporated in the body of said shedder to establish a magnetic field across said gap whose lines of flux are parallel to said direction of flow; and D. a pair of electrodes mounted on said shedder at axiallyspaced positions in said gap to produce a signal whose frequency is a function of flow rate.
Claim 4
Dependent Claim
108 words
A flowmeter of the vortex type comprising: A. a flow conduit forming a passage for the fluid to be measured; B. a vortex shedder mounted in said conduit transversely with respect to the direction of fluid flow, said shedder having an axially-extending gap at right angles to said direction of flow; C. permanent-magnet means incorporated in the body of said shedder to establish a magnetic field across said gap whose lines of flux are parallel to said direction of flow; and D. a pair of electrodes mounted on said shedder at axiallyspaced positions in said gap to produce a signal whose frequency is a function of flow rate.
Claim 5
Dependent Claim
29 words
A flowmeter as set forth in claim 1, wherein said shedder is formed by a pair of parallel bars whose ends are interconnected by a pair of permanent magnets.
Claim 6
Dependent Claim
21 words
A flowmeter as set forth in claim 1, wherein said shedder is formed by a pair of permanently magnetized parallel bars.
Claim 7
Dependent Claim
23 words
A flowmeter as set forth in claim 1, wherein said shedder is formed by a pair of parallel bars which incorporate permanent magnets.
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) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |