US4955230A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Elimination of turbulence for silicon micromachined airflow sensor
Assignee: Siemens Automotive LP
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Filing: 1989-08-07
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Granted: 1990-09-11
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Expires: 2009-08-07
Abstract
Abstract The sensor comprises a silicon sensing element on a ceramic substrate. A slot is provided in the substrate just ahead of the leading edge of the silicon so that some of the airflow that is flowing toward the leading edge surface of the silicon passes through the slot. This promotes a less turbulent flow over the sensing face of the silicon.
Inventors
- 👤 Bryan C. Hall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:42
CPC Classifications
G; G01; G01F; G01F5/00; G01F1/00; G01F1/68; G01F1/684; G01F1/6842
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
105 words
In a solid-state mass airflow sensor comprising a substrate having a surface containing a semi-conductor sensing element, said semi-conductor sensing element having a leading edge surface in the direction of airflow and a flat exposed sensing surface extending downstream from said leading edge, the improvement which comprises a slot through said substrate just forward of and generally parallel with said leading edge surface so that a portion of the airflow toward said leading edge surface is caused to pass through said slot and thereby promote smooth flow over said exposed sensing surface to enhance the accuracy of the sensing element in measuring mass air flow.
Claim 2
Dependent Claim
105 words
In a solid-state mass airflow sensor comprising a substrate having a surface containing a semi-conductor sensing element, said semi-conductor sensing element having a leading edge surface in the direction of airflow and a flat exposed sensing surface extending downstream from said leading edge, the improvement which comprises a slot through said substrate just forward of and generally parallel with said leading edge surface so that a portion of the airflow toward said leading edge surface is caused to pass through said slot and thereby promote smooth flow over said exposed sensing surface to enhance the accuracy of the sensing element in measuring mass air flow.
Claim 3
Dependent Claim
26 words
The improvement set forth in claim 1 wherein the length of said leading edge surface and said slot are straight and substantially perpendicular to the flow.
Claim 4
Dependent Claim
48 words
The improvement set forth in claim 2 wherein said leading edge surface and said sensing surface join at a sharp corner and said leading edge surface is inclined at an acute angle to the direction of flow so that said corner points roughly in the direction of flow.
Claim 5
Dependent Claim
48 words
The improvement set forth in claim 3 wherein said leading edge surface and said sensing surface are at a right angle to each other, said sensing surface is parallel to said substrate, and both said sensing element and said substrate are inclined at an angle to the airflow.
Claim 6
Dependent Claim
52 words
The improvement set forth in claim 3 wherein said substrate and said sensing element are arranged to be parallel to the flow and said leading edge surface is arranged to be non-parallel to said sensing surface, said sharp corner at which said leading edge surface and said sensing surface join being acute-angled.
References Cited (Backward Citations)
US4856328A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-10 | 1994-03-12 | 1994-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-10 | 1998-03-12 | 1998-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-10 | 2002-03-12 | 2002-09-11 | $7700.00 | Window Closed / Lapsed |