US5014552A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flow meter
Assignee: Azbil Corp
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Filing: 1989-12-05
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Granted: 1991-05-14
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Expires: 2009-12-05
Abstract
Abstract A flow sensor comprising a flow passage, a rectifying element such as a plurality of screens or a honeycomb structure or both, arranged in the flow passage, a flow passage reducer for reducing the flow passage behind the rectifying element, and a thermal flow sensor, such as for example a micro bridge sensor, mounted at a location immediately behind the reducer. The above structure can largely reduce disturbance in flow to thereby enable highly accurate measurements of a wide range of flow without a low pass filter.
Inventors
- 👤 Shoji Kamiunten
- 👤 Shigeru Aoshima
- 👤 Takashi Tsumura
- 👤 Kouichi Ochiai
- 👤 Takashi Inaba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:18
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; G01F1/684; G01F1/6842
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
76 words
A flow sensor comprising: a flow passage having an inlet, an enlarged portion relative to said inlet and a narrow portion relative to said inlet; rectifying means arranged in said enlarged portion of said flow passage; a flow passage reducing means for reducing the flow passage behind said rectifying means; and a thermal flow sensor mounted on the inner wall of said narrow portion of said flow passage at a location immediately behind said reducing means.
Claim 2
Dependent Claim
76 words
A flow sensor comprising: a flow passage having an inlet, an enlarged portion relative to said inlet and a narrow portion relative to said inlet; rectifying means arranged in said enlarged portion of said flow passage; a flow passage reducing means for reducing the flow passage behind said rectifying means; and a thermal flow sensor mounted on the inner wall of said narrow portion of said flow passage at a location immediately behind said reducing means.
Claim 3
Dependent Claim
22 words
A flow sensor according to claim 1, wherein said rectifying means is a plurality of plane screens laterally spaced with each other.
Claim 4
Dependent Claim
15 words
A flow sensor according to claim 1, wherein said rectifying means is a honeycomb structure.
Claim 5
Dependent Claim
30 words
A flow sensor as in claim 1 wherein said flow passage reducing means gradually reduces the passage as it transitions from said enlarged passage portion to said narrow passage portion.
Claim 6
Dependent Claim
16 words
A flow sensor as in claim 4 wherein said passage reducing means follows a cosine function.
Claim 7
Dependent Claim
16 words
A flow sensor as in claim 4 wherein said flow sensor is a microbridge flow sensor.
References Cited (Backward Citations)
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Cited
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Cited
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Cited
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-13 | 1994-11-12 | 1995-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-13 | 1998-11-12 | 1999-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-13 | 2002-11-12 | 2003-05-14 | $7700.00 | Window Closed / Lapsed |