GB1003940A - Propellers, and convertiplanes equipped therewith - Google Patents

Abstract

1,003,940. Variable pitch and variable diameter propellers; convertible aircraft. A. M. YOUNG. Feb. 18, 1964, No. 6777/64. Headings B7V and B7W. A variable diameter screw propeller blade has an inboard section 20 (Figs. 3 and 5) mounted in a hub 18 and driven by a shaft 17, an outboard section 24 telescopically mounted in the inboard section and connected to a retracting mechanism to which torque is imparted by the drive shaft 17 to tend to retract the outboard section in opposition to centrifugal force. Relative movement of the sections may be prevented by a locking device. As shown in Fig. 3, cables 21, 22 attached to the outboard section are wound round a drum 25 mounted in bearings 29 on the hub and having a gear 36 meshing with a gear 35 attached to the planet wheels 31 of an epicyclic gear of which the ring gear 32 is fixed to the hub and the sun wheel 30 is fixed to the shaft 17. In another embodiment (Fig. 5) the shaft 17 drives by bevel gears 40, 41 a lead screw 37 on which is threaded a nut 38 fixed to the outer section. Alternatively (Fig. 6, not shown), the drive shaft terminates in a lead screw engaging a nut connected to the outer section by a cable passing over a pulley and splined to engage a hollow shaft depending from the hub. Two such propellers, each mounted on an engine nacelle, may drive a convertible aircraft (Fig. 7), being mounted on freely tiltable wings, or being freely tiltable relative to fixed wings (Fig. 9, not shown), or a single propeller may be freely tiltably mounted between the fuselages of a twin fuselage aircraft (Fig. 10, not shown). Tilting, and control in the helicopter mode, is effected by cyclic and collective pitch variations by rods 58, 51 respectively (Fig. 2) through a swash-plate 55. Specification 885,652 is referred to.