GB501472A - Improvement in flying machines - Google Patents

Abstract

501,472. Aeroplane convertible into helicopter. HOVLAND, A. N. Jan. 24, 1938, No. 2282. [Class 4] An aeroplane of the kind in which the wings can be released for operation as a helicopter is provided with an additional non-driven rotor for the purpose of stabilizing the machine during transition from helicopter to aeroplane flight. In aeroplane flight, the rotor blade frames 2, Fig. 1, may serve as braces for wings 3. The wings 3 are secured to a cylinder 5, Fig. 4, rotatable about a column 1, one wing being mounted through the intermediary of a turntable 6. The wings carry engines 11 driving air-screws 4 through shafts and worm gearing and in the case of one wing either a reversing gear or a reversible pitch air-screw is provided. An axially movable and rotatable cylinder 8 coaxial with the cylinder 5 carries a rotor frame 2. The rotor blade surfaces may comprise telescopic elements, silk or other fabric 9 adapted to be furled on or unfurled from spools at the blade roots, or " Venetian blind " surfaces comprising slats adjustable about longitudinal axes. In order to change from helicopter flight to aeroplane flight, the pilot slows down the rotation of wings 3 and arrests the wings by operation of a non-reactive control 26 which simultaneously causes a peg 18 to move into the path of a lug 16 formed on turntable 6 so as first to change the pitch angle of the wing and then to stop rotation, causes a peg 33 to strike the operating, mechanism of reversing gear 35 associated with the air-screw drive'on the wing, and causes release of a detent 36 permitting engagement of a spring-pressed locking pin 38 in registering holes formed in sleeve 5 and column 1. The wings are locked in their transverse position by pawls which become operative when the peg 18 is operated. The control of the engine throttles is effected through a cam-member 56 which is struck once a revolution by a similar member on a lever 58 connected to the throttles. Lever 58 is maintained substantially in its deflected position by a pneumatic dashpot 59. After aeroplane flight is achieved the rotor surfaces may be furled by engagement of a lever 42 with a notch formed in a cone 43 freely rotatable on the axle 44 of the rotor and having internally of the axle a number of spools on which are wound the cables serving for the winding-in and paying-out of the fabric covering of the rotor frame. Rotation of the rotor is finally arrested by a pin 52 and when the blade frame is fully lowered, catches 10, Fig. 1, hold the frame 2 in position. The axle of the freely revolving rotor may be universally tiltable.