Patent US3782223A successfully refreshed from Google Patents.
US3782223A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power transmission systems
Assignee: Westland Group PLC
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Filing: 1972-05-15
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Granted: 1974-01-01
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Expires: 1992-05-15
Abstract
Abstract A power transmission system for a twin engine helicopter includes drive shafts and gearing connecting the engines to a rotor drive shaft and two gear trains, each gear train being arranged to drive a set of helicopter accessories. The transmission is arranged so that at least one of the gear trains remains operational through a wide range of failure conditions in both the engines and the transmission system.
Inventors
- 👤 K Watson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:26
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; F; F16; F16H; F16H35/00; F16H35/10; F16H2035/103; Y; Y10; Y10T; Y10T74/00; Y10T74/19; Y10T74/19014; Y10T74/19023; Y10T74/19126; Y10T74/1914
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
32 words
A power transmission system as claimed in claim 1 further comprising a fifth drive means interconnecting the first and second drive means, and a free-wheel unit located in said fifth drive means.
Claim 2
Dependent Claim
34 words
A power transmission system as claimed in claim 1 wherein the first and second gear trains and the double idler gear are housed in a gearbox separate from the remainder of the transmission system.
Claim 3
Dependent Claim
54 words
A power transmission system as claimed in claim 1, wherein the first and second gear trains rotate at different speeds so that during twin engine operation overriding of the free-wheel unit in the double idler gear ensures that the first and second gear trains are driven independently by the first and second engines, respectively.
Claim 4
Dependent Claim
43 words
A power transmission system as claimed in claim 1, wherein said double idler gear comprises two idler gears meshing with said first and second gear trains, respectively, and coupled together through said free-wheel unit in said idler gear and said overload protection device.
References Cited (Backward Citations)
US2380889A
Cited
US2979968A
Cited
US3220283A
Cited
US3255825A
Cited
US3362255A
Cited
US3455182A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |