US4176546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aircraft instruments
Assignee: Smiths Group PLC
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Filing: 1978-11-22
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Granted: 1979-12-04
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Expires: 1998-11-22
Abstract
Abstract An aircraft-speed indicating instrument has an index which is movable against a scale to provide a reading of airspeed, and a digital indicator which is selectively operable to provide a digital reading of either Mach number or the airspeed. The index and the digital indicator are driven by respective control systems supplied with a multiplexed electrical signal containing information representative of both Mach number and airspeed. Each control system includes gating means which is operable to pass only those parts of the multiplexed signal necessary for the associated control means to provde the desired reading.
Inventors
- 👤 Harry Gibson
- 👤 John W. D. Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:13
CPC Classifications
G; G01; G01P; G01P1/00; G01P1/07; G01P1/08; Y; Y10; Y10S; Y10S116/00; Y10S116/43
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
44 words
An aircraft-speed indicating instrument including an index that is moveable against a scale to provide a reading of airspeed, and a digital indicator, and wherein the digital indicator is arranged to provide selectively either a digital reading of Mach number or of said airspeed.
Claim 2
Dependent Claim
44 words
An aircraft-speed indicating instrument including an index that is moveable against a scale to provide a reading of airspeed, and a digital indicator, and wherein the digital indicator is arranged to provide selectively either a digital reading of Mach number or of said airspeed.
Claim 3
Dependent Claim
52 words
An aircraft-speed indicating instrument according to claim 1, wherein the readings provided by said digital indicator and said index are controlled by first and second control means respectively, and wherein said first control means is selectively operable to provide an output to said digital indicator indicative of either Mach number or airspeed.
Claim 4
Dependent Claim
75 words
An aircraft-speed indicating instrument according to claim 2, wherein said first control means is supplied with a signal containing information representative of both Mach number and airspeed, and includes first gating means and first responsive means, the first gating means being selectively operable to pass to the first responsive means either those parts of said signal which contain information representative of Mach number or those parts of said signal which contain information representative of airspeed.
Claim 5
Dependent Claim
16 words
An aircraft-speed indicating instrument according to claim 3, wherein said signal is a multiplexed electrical signal.
Claim 6
Dependent Claim
108 words
An aircraft-speed indicating instrument according to claim 4, including gate operating means for providing first and second pulsed gating signals which are synchronised with those parts of the multiplexed electrical signal containing information representative of Mach number and those parts of the multiplexed electrical signal containing information representative of airspeed respectively, and switch means for selectively supplying either said first or said second pulsed gating signals to the said first gating means of said first control means thereby to operate said first gating means and pass those parts of said multiplexed electrical signal representative of Mach number or airspeed in dependence upon the setting of said switch means.
Claim 7
Dependent Claim
56 words
An aircraft-speed indicating instrument according to claim 5, wherein said second control means is supplied with said multiplexed electrical signal and includes second gating means and second responsive means, the second gating means being operable to pass to the second responsive means only those parts of said multiplexed electrical signal which contain information representative of airspeed.
Claim 8
Dependent Claim
55 words
An aircraft-speed indicating instrument according to claim 6, wherein said second gating means is supplied with said second pulsed gating signal from said gate operating means thereby to operate said second gating means and pass to the said second responsive means only those parts of said multiplexed electrical signal which contain information representative of airspeed.
Claim 9
Dependent Claim
24 words
An aircraft-speed indicating instrument according to claim 7, wherein said switch means comprises a manually-operable switch located on the front face of the instrument.
Claim 10
Dependent Claim
16 words
An aircraft-speed indicating instrument according to claim 8, wherein the digital indicator is a digital-drum counter.
References Cited (Backward Citations)
US3453883A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-03 | 1983-06-04 | 1983-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-03 | 1987-06-04 | 1987-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-03 | 1991-06-04 | 1991-12-04 | $7700.00 | Window Closed / Lapsed |