L.Opdyke French Aeroplanes Before the Great War (Schiffer)
Deleted by request of (c)Schiffer Publishing
Flight, November 20, 1909
FLYER SILHOUETTES FROM THE PARIS SALON.
Helicopter with tandem lifting screws arranged to rotate in opposite directions. A third screw arranged as a propeller is intended to provide means for translation through space when the machine has once been raised from the ground. This latter propeller is of small diameter, but is driven at high speed, for the bevel-pinion on its shaft is one of those belonging to the reversing mechanism employed in the drive of the main screws. Provision is made for throwing the small propeller in and out of action at will by means of a jaw-clutch. The reversing gear, by means of which the lower lifting' screw rotates in an opposite direction to the upper, consists of two main bevel wheels in opposition and in mesh with a set of three planet pinions mounted in a stationary cage.
The pilot sits immediately in front of the vertical propeller-shaft, and the engine, not shown on the model exhibited, is placed beneath. At the pilot's left hand is a lever for working a progressive clutch which combines a reduction gear - of the epicyclic type - of such ratio that the speed of the vertical shaft is reduced to 500 r.p.m. In front of the pilot's seat is a fixed vertical triangular plane forming a prow to give steering-way, and behind the machine is a rudder.
The frame is built in pyramid form, mostly of bamboo, which is bound throughout with tape. Elsewhere hollow wood members are used.
The engine, when fitted, is to be of 120-h.p.; the machine weighs in its present state 169 kilogs. The lifting screws are 5 metres in diameter, and rotate at 500 r.p.m. The pitch is not given. The small propeller is 1.7 metres in diameter.