GB747172A - Improvements in or relating to propulsion mechanisms - Google Patents

Abstract

747,172. Propelling aircraft and ships. POWLEY, C. F. B. Oct. 4, 1951 [Oct. 19, 1950], No. 25555/50. Class 4. A propulsion mechanism comprises a plurality of aerofoils extending lengthwise between the end members of a cage, each of said aerofoils having a longitudinally extending surface which is concave with respect to the median plane and transversely thereof, and having shafts or spigots extending from the ends thereof and journalled in the said end members to support the aerofoil for angular displacement about a longitudinal axis corresponding substantially with the centre of pressure, said cage comprising a pair of annular end members united by brace members or struts secured thereto and being supported upon a shaft on the longitudinal axis thereof, means for rotating the cage, and means for effecting angular displacoment of said aerofoils to vary the angle of attack of the aerofoils as the cage is rotated, said lastmentioned means comprising elements on said shafts and means for operating said elements as the cage rotates whereby the aerofoils oscillate about said shafts. The embodiment described relates to the propulsion of aircraft and a fuselage 1 carries pylon structures 6 provided at their apices with bearings 11 to carry a transverse shaft 10 to which are fixed circular end members 8. Cambered aerofoils 12 are each pivotally mounted at each end in a member 8 by means of spigots 13 which are extended by cranks 14 that terminate in pegs 15 running in a grooved plate 17 eccentrically mounted so that the pitch of the blades is varied cyclically. The plates 17 are slotted at 18a for fore and aft movement on pegs 18 to enable the amplitude of the pitching angle to be varied. The blades may be formed with end plates (Figs. 8 and 9, not shown) and the blades may be formed with a diehedral angle (Fig. 7, not shown). Other methods of causing pitch-changing movements of the blades are described which incorporate radially disposed push rods having rollers at their inner ends to engage a central cam and, at their outer ends, either pivotal connections with the aerofoils at points offset from spigots 13 or toothed racks which engage pinions coaxial with the spigots. Specification 189,751, [Class 4], is referred to.