US4373387A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air flow meter
Assignee: Hitachi Ltd
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Filing: 1980-07-14
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Granted: 1983-02-15
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Expires: 2000-07-14
Abstract
Abstract An air flow meter comprises an air velocity measuring resistor and a temperature compensating resistor and is installed in a bypass passage provided at an intake passage running through an air horn. The air velocity measuring resistor and the temperature compensating resistor are supported by lead wires whose portions exposed in the bypass passage have the same length. A cover forming the bypass passage is made of heat insulating synthetic resin material to prevent heats from being transmitted to the resistors.
Inventors
- 👤 Yutaka Nishimura
- 👤 Hiroshi Kuroiwa
- 👤 Tadashi Kirisawa
- 👤 Yoshishige Oyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:25
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; G01F1/684; G01F1/6842; G01F1/696; G01F1/698; G01F5/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
97 words
An air flow meter comprising an air flow velocity measuring resistor and a temperature compensating resistor installed in an air flow passage through lead wires exposed therein and supporting said resistors, said air velocity measuring resistor being heated to a predetermined temperature higher than that of said air drawn in said passage, said temperature compensating resistor being heated to a temperature almost equal to that of said air drawn in, and said temperature compensating resistor being supported by lead wires having no less heat resistance than that of the lead wires supporting said air velocity measuring resistor.
Claim 2
Dependent Claim
97 words
An air flow meter comprising an air flow velocity measuring resistor and a temperature compensating resistor installed in an air flow passage through lead wires exposed therein and supporting said resistors, said air velocity measuring resistor being heated to a predetermined temperature higher than that of said air drawn in said passage, said temperature compensating resistor being heated to a temperature almost equal to that of said air drawn in, and said temperature compensating resistor being supported by lead wires having no less heat resistance than that of the lead wires supporting said air velocity measuring resistor.
Claim 3
Dependent Claim
29 words
An air flow meter as set forth in claim 1, wherein the lead wires supporting said temperature compensating resistor are longer than those supporting said air velocity measuring resistor.
Claim 4
Dependent Claim
31 words
An air flow meter as set forth in claim 1, wherein the lead wires supporting said temperature compensating resistor have the same length as those supporting said air velocity measuring resistor.
Claim 5
Dependent Claim
34 words
An air flow meter as set forth in claim 1, 2 or 3, wherein the lead wires supporting said temperature compensating resistor are smaller in diameter than those supporting said air velocity measuring resistor.
Claim 6
Dependent Claim
35 words
An air flow meter as set forth in claim 1, 2 or 3, wherein the lead wires supporting said temperature compensating resistor have the same diameter thereof as those supporting said air velocity measuring resistor.
Claim 7
Dependent Claim
40 words
An air flow meter as set forth in claim 1, 2 or 3, wherein said air velocity measuring resistor and said temperature compensating resistor are installed in a bypass passage provided at an intake passage running through an air horn.
Claim 8
Dependent Claim
37 words
An air flow meter as set forth in claim 6, wherein the bypass passage has a rectangular cross section with a longer lateral side, and is formed by a member made of heat insulating synthetic resin material.
Claim 9
Dependent Claim
32 words
An air flow meter as set forth in claim 1, 2 or 3, wherein the configuration of said air velocity measuring resistor is the same as that of said temperature compensating resistor.
Claim 10
Dependent Claim
30 words
An air flow meter as set forth in claim 1, 2 or 3, wherein said air velocity measuring resistor is made of the same material as said temperature compensating resistor.
Claim 11
Dependent Claim
37 words
An air flow meter as set forth in claim 1, 2 or 3, wherein said air velocity measuring resistor has the same shape and size and is made of the same material as said temperature compensating resistor.
Claim 12
Dependent Claim
37 words
An air flow meter as set forth in claim 1, wherein said air velocity measuring resistor is arranged above said temperature compensating resistor in a bypass passage provided at an intake passage running through an air horn.
Claim 13
Dependent Claim
43 words
An air flow meter as set forth in claim 11, wherein said air velocity measuring resistor and said temperature compensating resistor are disposed at positions offset from one another in the direction of air flow of the air stream drawn in said passage.
Claim 14
Dependent Claim
40 words
An air flow meter as set forth in claim 1, wherein said air velocity measuring resistor and said temperature compensating resistor are arranged side by side in a bypass passage provided at an intake passage running through an air horn.
References Cited (Backward Citations)
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US3747577A
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US3891391A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-02-14 | 1986-08-16 | 1987-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-14 | 1990-08-16 | 1991-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-14 | 1994-08-16 | 1995-02-15 | $7700.00 | Window Closed / Lapsed |