US4326412A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flowmeter of hot wire type
Assignee: Nissan Motor Co Ltd
•
Filing: 1979-07-31
•
Granted: 1982-04-27
•
Expires: 1999-07-31
Abstract
Abstract The flow rate is determined from the heat transferred from an electrically heated wire stretched in a fluid flow to the fluid. The wire is placed not on a plane normal to the flow but within a section of the fluid passage bounded by two spaced planes normal to the flow. Preferably the wire is composed of series of line segments which are distributed evenly not only around the central axis of the passage but also in the direction of the flow so that the heat release from the wire in its entirety corresponds to the mean value of fluid velocities at various points.
Inventors
- 👤 Hiroshi Kobayashi
- 👤 Toru Kita
- 👤 Takeshi Fujishiro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:56
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; G01F1/684; G01F1/688; G01F1/69
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
118 words
A flowmeter of a hot wire type for a measurement of flow rate of fluid flowing through a fluid passage, the flowmeter comprising: an electrically heatable wire stretched within a section of the fluid passage bounded by two spaced planes normal to the direction of the fluid flow; means for electrically measuring the temperature drop of the wire caused by the fluid flow in the fluid passage; said wire being wound around the central axis of said fluid passage like a helix traced on a side surface of a barrel shape in such a manner that the heat release from said wire in its entirety approximates the mean fluid velocity averaged within said section of said fluid passage.
Claim 2
Dependent Claim
118 words
A flowmeter of a hot wire type for a measurement of flow rate of fluid flowing through a fluid passage, the flowmeter comprising: an electrically heatable wire stretched within a section of the fluid passage bounded by two spaced planes normal to the direction of the fluid flow; means for electrically measuring the temperature drop of the wire caused by the fluid flow in the fluid passage; said wire being wound around the central axis of said fluid passage like a helix traced on a side surface of a barrel shape in such a manner that the heat release from said wire in its entirety approximates the mean fluid velocity averaged within said section of said fluid passage.
Claim 3
Dependent Claim
174 words
A flowmeter of a hot wire type for a measurement of flow rate of fluid flowing through a fluid passage, the flowmeter comprising: an electrically heatable wire stretched in three dimensions within a section of the fluid passage bounded by two spaced planes normal to the direction of the fluid flow in such a manner that the heat release from said wire in its entirety approximates the mean fluid velocity averaged within said section of said fluid passage; means for electrically measuring the temperature drop of the wire caused by the fluid flow in the fluid passage; wherein said wire is arranged to be generally symmetrical around the central axis of said fluid passage in a plan view normal to the direction of the flow, and wherein said wire is distributed, in a plan view normal to the direction of the flow, both inside and outside a circle having a center lying on the central axis of said fluid passage and dividing a cross sectional area of said fluid passage into two equal areas.
Claim 4
Dependent Claim
174 words
A flowmeter of a hot wire type for a measurement of flow rate of fluid flowing through a fluid passage, the flowmeter comprising: an electrically heatable wire stretched in three dimensions within a section of the fluid passage bounded by two spaced planes normal to the direction of the fluid flow in such a manner that the heat release from said wire in its entirety approximates the mean fluid velocity averaged within said section of said fluid passage; means for electrically measuring the temperature drop of the wire caused by the fluid flow in the fluid passage; wherein said wire is arranged to be generally symmetrical around the central axis of said fluid passage in a plan view normal to the direction of the flow, and wherein said wire is distributed, in a plan view normal to the direction of the flow, both inside and outside a circle having a center lying on the central axis of said fluid passage and dividing a cross sectional area of said fluid passage into two equal areas.
Claim 5
Dependent Claim
28 words
A flowmeter claimed in claim 2, wherein said wire is composed of a series of line segments lying end to end at an angle with each adjacent segment.
Claim 6
Dependent Claim
28 words
A flowmeter claimed in claim 3, wherein said segments have substantially the same angle with a plane normal to the direction of the flow and lie successively downstream.
Claim 7
Dependent Claim
38 words
A flowmeter claimed in claim 4, wherein said wire is arranged substantially in a form of a regular triangle inscribed in the circumference of said fluid passage in a plan view normal to the direction of the flow.
Claim 8
Dependent Claim
55 words
A flowmeter claimed in claim 4, wherein said wire is arranged to be substantially in a form of a cross whose intersecting point lies on the central axis of said fluid passage and whose end points lie on the circumference of said fluid passage, in a plan view normal to the direction of the flow.
Claim 9
Dependent Claim
34 words
A flowmeter claimed in claim 3, wherein said wire is wound helically around the central axis of said fluid passage like a cobweb in a plan view normal to the direction of the flow.
Claim 10
Dependent Claim
24 words
A flowmeter claimed in claim 7, wherein said segments have substantially the same angle with a plane normal to the direction of the flow.
Claim 11
Dependent Claim
119 words
A flowmeter of a hot wire type for a measurement of flow rate of fluid flowing through a fluid passage, the flowmeter comprising: an electrically heatable wire stretched within a section of the fluid passage bounded by two spaced planes normal to the direction of the fluid flow; means for electrically measuring the temperature drop of the wire caused by the fluid flow in the fluid passage; and said wire being wound around the central axis of said fluid passage like a helix traced on a side surface of an hourglass shape in such a manner that the heat release from said wire in its entirety approximates the mean fluid velocity averaged within said section of said fluid passage.
Claim 12
Dependent Claim
119 words
A flowmeter of a hot wire type for a measurement of flow rate of fluid flowing through a fluid passage, the flowmeter comprising: an electrically heatable wire stretched within a section of the fluid passage bounded by two spaced planes normal to the direction of the fluid flow; means for electrically measuring the temperature drop of the wire caused by the fluid flow in the fluid passage; and said wire being wound around the central axis of said fluid passage like a helix traced on a side surface of an hourglass shape in such a manner that the heat release from said wire in its entirety approximates the mean fluid velocity averaged within said section of said fluid passage.
References Cited (Backward Citations)
GB533226A
Cited
US2319516A
Cited
US2412471A
Cited
US2650496A
Cited
FR56854E
Cited
US2981104A
Cited
US3251225A
Cited
GB1086742A
Cited
DE1905999U
Cited
US3971247A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-04-26 | 1985-10-26 | 1986-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-26 | 1989-10-26 | 1990-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-26 | 1993-10-26 | 1994-04-27 | $7700.00 | Window Closed / Lapsed |