US4517838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal mass flow meter
Assignee: Ohkura Electric Co Ltd
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Filing: 1983-11-10
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Granted: 1985-05-21
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Expires: 2003-11-10
Abstract
Abstract The disclosed thermal mass flow meter has a heat conductive case having a fine groove and a sensor pipe disposed in said fine groove so as to carry fluid flow to be measured.
Inventors
- 👤 Akira Wachi
- 👤 Munehisa Hayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:08
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; G01F1/684; G01F1/6847
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
81 words
A thermal mass flow meter, comprising a case whose heat conductivity is much larger than that of air, a fine groove with an equivalent diameter of not larger than 4 mm bored through the case, a sensor pipe disposed in said fine groove so as to carry a fluid flow to be measured therethrough, and means for supporting said sensor pipe in said groove in spaced relationship with said case, and a heating and temperature-sensing means mounted on said sensor pipe.
Claim 2
Dependent Claim
81 words
A thermal mass flow meter, comprising a case whose heat conductivity is much larger than that of air, a fine groove with an equivalent diameter of not larger than 4 mm bored through the case, a sensor pipe disposed in said fine groove so as to carry a fluid flow to be measured therethrough, and means for supporting said sensor pipe in said groove in spaced relationship with said case, and a heating and temperature-sensing means mounted on said sensor pipe.
Claim 3
Dependent Claim
41 words
A thermal mass flow meter as set forth in claim 1, wherein said heating and temperature-sensing means is made of two windings wound on said sensor pipe and said means for supporting comprises a flange-like spacer disposed between said two windings.
Claim 4
Dependent Claim
30 words
A thermal mass flow meter as set forth in claim 1, wherein said meter further comprises a thermal insulator stuffed between inner surface of said groove and said sensor pipe.
Claim 5
Dependent Claim
42 words
A thermal mass flow meter as set forth in claim 1, wherein said heating and temperature-sensing means consists of a pair of windings which are connected both to a power source and to a voltage-detecting circuit for heating and detecting the temperature.
Claim 6
Dependent Claim
46 words
A thermal mass flow meter as set forth in claim 1, wherein said sensor pipe is adapted to carry an electric current for heating and said heating and temperature-sensing means consists of two temperature-sensitive resistances mounted on said sensor pipe at upstream and downstream positions thereof.
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) | 1988-05-20 | 1988-11-19 | 1989-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-20 | 1992-11-19 | 1993-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-20 | 1996-11-19 | 1997-05-21 | $7700.00 | Window Closed / Lapsed |