GB564803A - Improvements in and relating to air-craft of the rotary wing type - Google Patents

Abstract

564,803. Aircraft supported by rotating blades. BURNS, J. S., and MANSON, R. K. Dec. 5, 1942, No. 17342. [Class 4] An aircraft is propelled and supported by at least one power-driven, multi-bladed rotor of which the blades are cyclically feathered about radial axes during rotation of the rotor, for which purpose the shafts carrying the blades have pinions engaging toothed sectors pivoted in a rotatable hub and oscillated by a pin arranged eccentrically of the hub and engaging slots in the sectors. An aircraft is described having two four-bladed rotors 1, 2 mounted on horizontal longitudinal axes in bearings 7 on opposite sides of the fuselage. The blades are feathered so that the downwardly moving blades are broadside on as they pass through the horizontal plane of the aircraft. The blades of each rotor are mounted in pairs on two shafts 14, 15, Fig. 2, journalled in a hollow hub 13, driven by worm gear 10, 11 through a freewheel clutch, the worms 11 being mounted on shafts 12 connected to a central differential gear driven by an engine. Each shaft 14, 15 has a pinion 25 gearing with a toothed sector 16, 17 pivoted near the circumference of the hub, the sector 16 being shown pivoted at 54. The two sectors have central slots 23, 24 engaged by a pin 22 set eccentrically on the end of a normally stationary shaft 8 which is journalled in an eccentric bore in a sleeve 21 journalled in a sleeve 9 carrying the worm-wheel 10 and hub 13. The shaft 8 and sleeve 21 are fitted respectively with sprockets 44, 46 by turning which the pin 22 may be set centrally, in which case the blades do not feather, or displaced in any direction to vary the amplitude and phase of the feathering movement. As the incidence of one blade increases that of the opposite blade diminishes, the two blade surfaces being approximately at right angles to one another. Corresponding sprockets 45, 47, Fig. 6, are mounted on the opposite side of the aircraft and a chain 48 passes around the sprockets 44, 45 from the ends of a lever 34, and a chain 50 passes around the sprockets 46, 47 from the ends of a lever 29 mounted on a fixed bracket 26, the lever 29 being connected by cables 30 to pedals 28. The lever 34 can be moved relatively to the lever 29 to centre or excentre the pin by a lever 35 having a threaded boss engaging a screwed spindle 31 pivoted to the lever 29. The phase of feathering is then controlled by moving both levers together by means of the pedals. A helicopter machine also is described in which two similar rotors are mounted on vertical axes, the propulsion of the machine in any direction being effected by the horizontal thrust of the blades when feathered.