Electrically controlled elevator
US4304375A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 17, 1979 |
| Grant date | Dec 8, 1981 |
| Priority date | — |
| Expiry date | May 17, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64C2027/8281
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A helicopter elevator (12, 13) is driven by an electrical actuator (20) to position the elevator (12, 13) to an optimum angle of incidence for given flight conditions. The actuator (20) is included within a servo loop which responds to a command signal derived from an electronics module (69). Transducers which measure longitudinal cyclic position (40), collective pitch position (41) and air speed (42) generate signals which are summed in a summation unit (43). The output of the summation unit (43) is passed through a signal multiplier (45) which has the gain thereof set inversely proportional to air speed. A trigger unit (56) activates the signal multiplier (45) at an air speed above a preset threshold. An integrator (54) integrates the sum of the outputs of the longitudinal cyclic position transducer (40) and air speed transducer (42) to compensate for different center of gravity aircraft loadings. Duplicate electronic systems are provided to drive a pair of servo motors (36a, 36b) with brakes provided to lock the actuator (20) when an electronic failure is detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.