GB335670A - Improvements in and relating to the propulsion of aircraft - Google Patents

Abstract

335,670. Killen, J. W. July 24, 1929. Propelling.-Aircraft are propelled by pairs of oppositely rotating propellers each consisting of spoked wheels having blades with relatively large trailing areas pivoted about the spokes and adjusted cyclically by directly mounted cams engaging a cam race concentric with the propeller axis or by screw gear to give symmetrical axial and lift thrusts. Fig. 2 shows four blades c mounted on sleeves d which are internally screwed to engage quick pitched screws on arms b radiating from a wheel a. Tappets e on the sleeves d engage the inner surface of a cam ring f whereby the sleeves are given a reciprocating movement on the arms b to tilt the blades c out of the plane of the wheel at appropriate portions of the cycle. The tappets may be on the outer ends of the sleeves and engage a correspondingly enlarged cam ring. Fig. 4 shows an alternative construction wherein cams g on the sleeves engage between two cam rings h concentric with the propeller shaft. The blades are pivoted forward of their centres of pressure so that normally they remain in the plane of the propeller.