US3775673A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic karmen vortex sensing flow meters
Assignee: Yokogawa Electric Corp
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Filing: 1972-04-26
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Granted: 1973-11-27
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Expires: 1992-04-26
Abstract
Abstract In a Karman vortex flow meter of the type wherein a rod is inserted in fluid to be measured to create therein Karman vortices and a signal related to the vortices is detected to measure the flow velocity of the fluid, there are provided means contained in the rod for generating magnetic flux in the direction of the axis of the rod and a pair of electrodes mounted on the surface of the rod in contact with the fluid whereby to detect the magnetomotive forces including the variations in the velocity of the fluid caused by the Karman vortices created near the rod.
Inventors
- 👤 M Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:22
CPC Classifications
G; G01; G01P; G01P5/00; G01P5/08; G01F; G01F1/00; G01F1/05; G01F1/20; G01F1/32; G01F1/325; G01F1/3259; G01F1/3266
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
163 words
In a flow meter of the type wherein a rod is inserted in fluid to be measured said rod adapted to create Karman vortices in said fluid and a signal related to the vortices is detected to measure the flow velocity of the fluid, the improvement which comprises means contained in said rod for generating magnetic flux in the direction of the axis of said rod which flux extends into said fluid, a pair of electrodes mounted on the surface of said rod in contact with said fluid for coupling to the electromotive forces caused by motion of said rod through said fluid including the variations in the velocity of said fluid relative to said electrodes caused by the Karman vortices created near said rod, and detector means coupled to said electrodes and responsive to said electromotive forces caused by the Karman vortices but substantially insensitive to electromotive forces caused by means flow velocity past said rod for producing a flow velocity signal.
Claim 2
Dependent Claim
163 words
In a flow meter of the type wherein a rod is inserted in fluid to be measured said rod adapted to create Karman vortices in said fluid and a signal related to the vortices is detected to measure the flow velocity of the fluid, the improvement which comprises means contained in said rod for generating magnetic flux in the direction of the axis of said rod which flux extends into said fluid, a pair of electrodes mounted on the surface of said rod in contact with said fluid for coupling to the electromotive forces caused by motion of said rod through said fluid including the variations in the velocity of said fluid relative to said electrodes caused by the Karman vortices created near said rod, and detector means coupled to said electrodes and responsive to said electromotive forces caused by the Karman vortices but substantially insensitive to electromotive forces caused by means flow velocity past said rod for producing a flow velocity signal.
Claim 3
Dependent Claim
59 words
The flow meter according to claim 1 wherein said fluid is passed through a conduit, said rod is inserted in said conduit in perpendicular to the direction of flow of said fluid and said electrodes are mounted on said rod along a line perpendicular to the axis of said rod and to the direction of flow of said fluid.
Claim 4
Dependent Claim
30 words
The flow meter according to claim 1 wherein said magnetic flux generating means comprises a magnetic core coaxially contained in said rod and an exciting coil wound about said core.
Claim 5
Dependent Claim
44 words
The flow meter according to claim 1 wherein said magnetic flux generating means comprises a pair of magnetic cores arranged side by side in said rod in parallel with the axis thereof and a pair of coils wound in series opposition on said cores.
Claim 6
Dependent Claim
40 words
The flow meter according to claim 1 wherein said magnetic field generating means comprises a magnetic core disposed in said rod in the axial direction thereof and a pair of coils wound on said core and connected in series opposition.
Claim 7
Dependent Claim
30 words
The flow meter according to claim 1 wherein said magnetic flux generating means comprises a bar shaped permanent magnet in parallel with the axis of said rod between said electrodes.
Claim 8
Dependent Claim
29 words
The flow meter according to claim 1 wherein said magnetic flux generating means comprises a coil disposed in said rod for generating magnetic flux in parallel with said rod.
Claim 9
Dependent Claim
23 words
The flow meter according to claim 1 wherein said magnetic field generating means comprises a letter U-shaped loop conductor contained within said rod.
Claim 10
Dependent Claim
32 words
The flow meter according to claim 2 wherein said pair of electrodes are mounted on the surface of said rod on the upstream side with respect to the flow of said liquid.
Claim 11
Dependent Claim
32 words
The flow meter according to claim 2 wherein said pair of electrodes are mounted on the surface of said rod on the downstream side with respect to the flow of said liquid.
Claim 12
Dependent Claim
35 words
The flow meter according to claim 2 wherein a lateral opening is formed through said rod and said pair of electrodes are formed on the inner wall of said opening in contact with said fluid.
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) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |