GB404257A - Helicopter - Google Patents

Abstract

404,257. Machines supported by reciprocating propellers. GRETSCHER, E. W., 41, Wilhelmshavener Strasse, Berlin. April 4, 1932, No. 9619. Void [Abridged as open to inspection under Sect. 91 of the Acts, April 23, 1932]. [Class 4.] An aircraft supported by reciprocating propellers comprises two propeller surfaces a having pivoted plates a<1>, Fig. 10, and adapted to be reciprocated by separate axles b, c, one inside the other. The plates a<1> have a cross section like that of a bird's wing and are arranged so that the reciprocating movement causes rotation of the two propelling surfaces in opposite directions, each of which has a rim of air driving cells or blades f which assist the rotation by the air forced therethrough by the reciprocation. The aircraft is steered by braking one or other of the surfaces by a brake disc o controlled by a connection inside the axles b, c to the central wheel z. A frame v is pivoted to a casing t surrounding the axles and is tilted by connections x to a control wheel y in order to change the centre of gravity of the aircraft to control the speed and allow the machine to fly backwards or forwards. The blades a' open by pivoting about axles e, Fig. 10, on upward movement of the propelling surfaces a, which are reciprocated by two racks having treadles and connected by a pinion or by a chain passing over two pinions and carrying treadles. A locking lever U when released allows both surfaces a to be engaged with the brake disc o. Passenger seats or cabins may be accommodated in the widened lower part of the frame.