GB274534A - Improvements in or relating to planes for aircraft of the helicopter type - Google Patents

Abstract

274,534. Oldfield, W. R. March 16, 1926. Screw propellers.-The wings of a freely rotating wing-system are built up of telescopic sections which may be collapsed or extended longitudinally at the will of the pilot. In the machine described, the wing-system comprises four planes 2 connected by hinge fittings 4 to a freely-rotatable mast 6 mounted in a bearing 9 carried by the fuselage. The planes 2 each consist of a number of telescopic sections 3 of sheet metal covered externally or internally, or both, with fabric, and of progressively increasing thickness and width towards their tips. The outer open end of each section is braced by ribs 26 attached to angle pieces 27 which may be hinged to facilitate removal of the ribs. The sections are of tapering thickness so that when they are extended a wedge action is set up : the joints may be made .airtight by interposing rubber packing. The innermost sections are reinforced by tubular stays 21 braced, if desired, by tie wires. The planes are normally held collapsed by tension wires 12 incorporating springs or elastic cords and connected to the outermost sections, which also carry weights 28. A modification is referred to in which the sections 3 decrease in thickness and width towards the tips. The mast 6 is fitted at its base with a friction clutch 16, 17 operable by a lever 18. Normally this clutch holds the wing-system against rotation at which time the planes 2 are collapsed by the tension wires 12. When the clutch is released, the wing-system is rotated by the air stream and under centrifugal action aided by the weights 28 extends against the tension of the wires 12. If desired the main planes 8 may be made to telescope under the control of the pilot so that they may be collapsed when the rotary wing system is extended.