US3589832A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Propeller synchrophaser system
Assignee: GARETT CORP
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Filing: 1969-12-15
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Granted: 1971-06-29
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Expires: 1989-12-15
Abstract
Abstract A combined system for synchronizing engine speed and propeller blade phase on multiengine craft with hydraulic blade pitch adjustment wherein each engine has a speed sensor and propeller blade position sensor. Electronic signal comparator and error signal generating circuits effect adjustment of speed governors and propeller blade pitch actuators to first secure engine speed synchronization and propeller blade synchrophasing, the latter being performed without affecting the former.
Inventors
- 👤 George F Harris
- 👤 James W Massey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:50
CPC Classifications
B; B64; B64C; B64C11/00; B64C11/46; B64C11/50
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
123 words
Apparatus for synchrophasing variable pitch propellers on a multiengine craft, such propellers being of the type having a speed responsive governor, comprising: a. a first means responsive to the rotation of the propellers to generate signals corresponding to the speed and phase of operation thereof, such means having a part with elements corresponding to the number of blades on each propeller; b. circuit means connected with said first means for receiving and comparing the signals therefrom and generating error signals resulting from differences in phases of operation of the propellers; and c. electroresponsive means connected with said circuit means for effecting pitch adjustment of at least one of the variable pitch propellers, independently of the governor thereof, in response to such error signals.
Claim 2
Dependent Claim
123 words
Apparatus for synchrophasing variable pitch propellers on a multiengine craft, such propellers being of the type having a speed responsive governor, comprising: a. a first means responsive to the rotation of the propellers to generate signals corresponding to the speed and phase of operation thereof, such means having a part with elements corresponding to the number of blades on each propeller; b. circuit means connected with said first means for receiving and comparing the signals therefrom and generating error signals resulting from differences in phases of operation of the propellers; and c. electroresponsive means connected with said circuit means for effecting pitch adjustment of at least one of the variable pitch propellers, independently of the governor thereof, in response to such error signals.
Claim 3
Dependent Claim
37 words
A propeller synchrophasing apparatus as defined in claim 1 in which the pitch-varying means is fluid pressure responsive and the electroresponsive means is a valve means for controlling the application of fluid pressure to said pitch-varying means.
Claim 4
Dependent Claim
36 words
A propeller synchrophasing apparatus as defined in claim 1 in which the pitch-varying means is hydraulically operated and the electroresponsive means is a valve means for controlling the application of hydraulic pressure to said pitch-varying means.
Claim 5
Dependent Claim
86 words
A propeller synchrophasing apparatus as defined in claim 3 in which the circuit means generates error signals of a first type when certain differences in phases of propeller operation exist and error signals of a second type when certain other differences in phases of propeller operation exist, and said valve means is operative to apply hydraulic pressure to said pitch-varying means when the first type error signals are received and to bleed hydraulic pressure from said pitch-varying means when the second type error signals are received.
Claim 6
Dependent Claim
29 words
A propeller synchrophasing apparatus as defined in claim 3 in which a bypass extends around the speed responsive governor and the electroresponsive valve means communicates with the bypass passage.
Claim 7
Dependent Claim
65 words
A propeller synchrophasing apparatus as defined in claim 5 in which the electroresponsive valve means has an element in the bypass passage to apply fluid pressure to the pitch-varying means to change the blade pitch in one direction and another element between the bypass passage and an outlet to remove fluid pressure from the pitch-varying means to change the blade pitch in the opposite direction.
Claim 8
Dependent Claim
81 words
A propeller synchrophasing apparatus as defined in claim 1 in which the circuit means has portions for generating error signals resulting from differences in both engine speeds and propeller blade phases of operation and the electroresponsive means has a first portion responsive to speed error signals to adjust the speed governor of a selected engine and a second portion responsive to blade phase error signals to effect pitch adjustment of the propeller of the selected engine independently of the governor thereof.
Claim 9
Dependent Claim
40 words
A propeller synchrophasing apparatus as defined in claim 7 in which the pitch-varying means is fluid pressure responsive and the second portion of the electroresponsive means has valve means for controlling the application of fluid pressure to said pitch-varying means.
Claim 10
Dependent Claim
28 words
A propeller synchrophasing apparatus as defined in claim 7 in which means are provided for selectively effecting the adjustments of the speed governor and the propeller blade pitch.
References Cited (Backward Citations)
US3007529A
Cited
US3066741A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |