Adjustable pitch propeller for model aircraft - has blades clamped at required angle of pitch between serrated discs

摘要

A propeller for a power driven model aircraft has two blades (30) (32) with the inner end (34) of circular cross section between two flanges (36)(38). A longitudinal ridge (40) if triangular cross section runs between the flanges (36)(38). The blades (30(32) are clamped between the discs (12)(14) by bolts. The disc (12) has semicircular recesses (42) with longitudinal serrations (46). When the blades are assembled the ridge (40) is arranged to fit in one of the serrations (46) to give the required angle of blade pitch. This design of propeller enables the pitch to be adjusted to suit the aircraft type and power of the engine and so achieve maximum speed or rate of climb.