GB487811A - Improvements in or relating to aircraft having rotative wing systems - Google Patents

Abstract

487,811. Aircraft with rotary - wing systems. SOC. ANON. DES ATELIERS D'AVIATION L. BREGUET. July 1, 1937, No. 18324. Convention date, July 20, 1936. [Class 4] An aircraft includes a pair of oppositely revolving coaxial wings adapted freely to flap in a plane including the axis of revolution of the wings, and spacing means between the two revolving wings preventing, in operation, the clearance between the wings falling below a predetermined amount irrespective of the incidence of the wings. In one form the blade roots are provided with cams 11, 12, 13, 14, of circular or other profile. The cams 11, 12 contact rollers 15, 16 on levers 19, 20 respectively pivoted to hub-members 23, 24. The inner ends of the levers engage an annular race 29 carried on a universal joint member 31 which is axially displaceable on annular member 30. The cam members 13, 14 can contact rollers 17, 18 on levers 21, 22 pivoted to hub-members 25, 26 to limit displacement about the flapping blade-pivots and prevent contact of the blades of the two coaxial systems. The inner ends of the levers 21, 22 engage an annular race 34 universally movable on a ball element which is axially displaceable on the member 30, to correlate the movement of the two sets of levers, the races 29, 34 are connected by parallel rods 35, 36. In a modification, the blades 7, 8 are connected by links 50, 51 to a ring 49 rotatable on a member 38 mounted on anaxially-displaceable ball-joint 47. The member 38 is connected to the blades 1, 2 by dashpots 39, 41, 40, 42 having air vents w<1>, w<2> adapted to be meshed by the pistons 41, 42. Means may be provided for varying rotor blade pitch. Specifications 352,521, 373,771, and 423,005 are referred to.