GB230190A - Improvements in helicopters - Google Patents

Abstract

230,190. Armstrong, J. J. V., (Eerliner, H. A.). Dec. 10, 1923. Aeroplanes; helicopters; planes, arrangement of; propelling; steering.-A helicopter having one or more separate propellers arranged at the tail away from the centre of lift to control the tilting of the machine fore and aft, has oppositely rotating lifting-propellers, spaced from each other and having their axes normally parallel, one or both of these propelers being adapted to be tilted the one relatively to the other in a plane or planes at right angles to the plane normally containing the axes of the propellers in order to produca a horizontal steering-couple. A machine is described similar to that shown in Specification 204,079, having three superposed planes above which two propellers are mounted' on shafts in casings which can turn about a transverse tube containing the driving shaft. The propellershafts are connected to the driving shaft by bevel gear contained in the casings. The Figure shows the upper ends of the propeller-shafts 7, 8, connected by cables to four levers 18. 18<a>, 18<b>, 18<c>, on shafts carrying quadrants connected to an endless cable 24. This cable is connected by a lever 22 and a rod 21 to a rudder bar 20 which also actuates a rudder through cables 25, 26. Instead of pivoted casings being used, the propeller shafts may be mounted on planes made sufficiently warpable to permit the movement of the shafts. The propeller shafts may be mounted on the longitudinal centre line of the machine instead of transversely as shown.