US4224570A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Engine speed indicator
Assignee: LAC DU FLAMBEAU BAND OF LAKE SUPERIOR CHIPPEWA INDIANS
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Filing: 1978-12-11
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Granted: 1980-09-23
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Expires: 1998-12-11
Abstract
Abstract An engine rpm sensor utilizes a gas filled lamp for connection to a circu including an engine ignition system and a spark plug. A light pipe is exposed to the lamp and couples an optical signal each time a spark plug is fired to a remote location for utilization in a display or indicating device.
Inventors
- 👤 Francis P. Meserow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:08
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/48; G01P3/4802; G01P3/4807; G01P3/481; G01P3/486
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
70 words
Internal combustion engine speed sensing apparatus comprising: a current responsive light producing device; means for connecting said device to the firing circuit for a spark plug in an internal combustion engine whereby said device will produce light each time the spark plug is fired; means for producing an electrical signal in response to light generated by said device; and means for providing a visible indication of the light so produced.
Claim 2
Dependent Claim
70 words
Internal combustion engine speed sensing apparatus comprising: a current responsive light producing device; means for connecting said device to the firing circuit for a spark plug in an internal combustion engine whereby said device will produce light each time the spark plug is fired; means for producing an electrical signal in response to light generated by said device; and means for providing a visible indication of the light so produced.
Claim 3
Dependent Claim
22 words
The apparatus of claim 1 including a light pipe coupling light from said device to said means for producing an electrical signal.
Claim 4
Dependent Claim
15 words
The apparatus of claim 2 wherein said device is constituted by a gas filled lamp.
Claim 5
Dependent Claim
23 words
The apparatus of claim 3 including a closed protective housing in which said device and one end of said light pipe are mounted.
Claim 6
Dependent Claim
23 words
The apparatus of claim 4 including means for connecting said device in series between a high voltage ignition source and a spark plug.
Claim 7
Dependent Claim
23 words
The apparatus of claim 4 including means for connecting said device in parallel with a high voltage ignition source and a spark plug.
Claim 8
Dependent Claim
24 words
The apparatus of claim 4 wherein said last mentioned means is constituted by a meter providing an indication of engine revolutions per unit time.
Claim 9
Dependent Claim
25 words
The apparatus of claim 4 wherein the last mentioned means is constituted by an instrument responsive to the particular time the spark plug is fired.
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) | 1983-09-23 | 1984-03-24 | 1984-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-23 | 1988-03-24 | 1988-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-23 | 1992-03-24 | 1992-09-23 | $7700.00 | Window Closed / Lapsed |