Improvements in and relating to an arrangement for controlling the pitch of a variable-pitch propeller with two speeds of pitch-changing

摘要

642,152. Friction clutches. AIR-EQUIPEMENT. Oct. 7, 1947, No. 26917. Convention date, Oct. 14, 1946. [Class 80(ii)] [Also in Group XXXIII] Electromagnetic clutches for use in the pitch changing mechanism of screw propellers (see Group XXXIII) comprise a clutch disc 12 adapted to be driven by either of electromagnetic clutch plates 4, 8 and connected to an output shaft 14 through a torque limiting device. The latter comprises a series of discs 33, connected to the clutch disc 12, in frictional engagement with another series of discs 34 connected to a sliding collar 35 adapted to slide in grooves in the shaft 14. The discs are pressed together by springs 36 which are calibrated to limit the torque transmitted. Specification 519,667, [Group XXXIII], is referred to.