Patent GB-300902-A (GB)
Title: Improvements in and relating to helicopters
IPC: B64C27/04
Filed: 1928-11-14
Abstract: 300,902. Perrin, E. A. Nov. 19, 1927, [Convention date]. Aeroplanes; helicopters; propelling; steering and balancing.-A helicopter supported by a single screw is provided with lateral planes 93, fitted with ailerons 96, which can be adjusted from a vertically edge-on position through varying degrees of inclination to a horizontal position within the slip stream from the propeller during transition from vertical to horizontal flight. Lateral and longitudinal balance is maintained by cyclic variations of the pitch of the screw blades during purely vertical flight, gyroscopic precession being utilized, but as the horizontal component of flight increases these controls are gradually replaced respectively by elevator and aileron control. Direction is controlled in the two cases respectively by the ailerons or the planes and! by a rudder 100. Should the propeller stop a gliding flight is effected, and for stabilizing purposes the longitudinal and lateral controls are reversed by the pilot to compensate for the absence of gyroscopic effect. The lateral planes may be supplemented by other preferably radiating blades 97 in the spaces between the lateral planes and fuselage. The blades are of variable inclination and during horizontal flight may be swung against the fuselage as shown. During vertical flight an asymmetric setting of the planes and blades counteracts reactive torque. During the transition from vertical to horizontal flight the progressive increase in the aileron control is accompanied by a progressive interconnection to the rudder to compensate for disturbances in the direction, or this interconnection may be constant and its effect dependent only on the horizontal speed. A residual variation of blade pitch is left during horizontal flight to compensate for the variation in the effective lift of the advancing and retreating screw blades. The lifting propeller is mounted on a shaft 62 which is connected by a cardan joint at its lower end to an outer shaft 61 which is driven through two free wheel clutches 60 and bevel and spur gearing from two engines 50, 51. The propeller blades 72 are pivoted about a shaft 71 and are connected by links to a lever 74 which can be eccentered to effect the cyclical variation of pitch by mechanism not shown. Variation of pitch as a whole is effected, irrespective of any cyclical variation, by a frame 88, Fig. 13, having pins working in radial slots in the lever 74 and in a lever 87 connected by a pin 86, passing through slots in the shaft 62, to a vertical shaft 84. This shaft extends to the lower end of the shaft 62 and is connected to the shaft 61 by a pin 85, passing through slots in the shaft 62. Relative rotation of the shafts 61, 62 is effected by bell crank levers 82 pivoted to the shaft 62 and engaging notches in a collar 83 on the shaft 61. The bell cranks are connected by links 81 to levers 79 having rollers engaging a collar 77 which can be raised and lowered by a lever 76. Each plane 93, Fig. 10, is connected by arms 94, 132 to a, sleeve working on a quadrant 95 and provided with means 133 for locking it at various inclinations. The plane is tilted by a connection OP and the ailerons 96 are moved by cable connections AP. The same connection OP swings the blades 97 towards or away from the fuselage, a separate connection to the direction control DV, Fig. 8, effecting the tilting of the blades about the radial axes. The elevators 101, Figs. 3 and 12, are preferably hinged about both longitudinal and transverse axes. Levers 142 and links 143 ensure that their incidence decreases as they rise and increases as they fall about their longitudinal axes. The forward ends of the levers 142 are connected to cables 144 anchored to oppositely directed levers 145 on a shaft having a third lever connected by a cord 146 to a normally untensioned spring 147. This cord 146 passes through a tube 148 pivoted at 150 which can be moved by controls TC to actuate the elevators and tension the spring 147. The spring allows the elevators to give under gusts. Fig. 9 shows a universally mounted lever 121 for actuating the lateral and longitudinal controls TC, LC respectively by links connected to the opposite ends of two slotted levers 123, 124. Rods 126, 127 connected to blocks in the slots are coupled by the links 130, 131 to a lever 129 to switch over the controls when the lifting screw stops. Fig. 8 shows the means for progressively reducing the effect of the controls for vertical flight and changing over to those for horizontal flight. A lever VV is connected by links 105 - - 108 to links 109 - - 112 to move their ends along slots in levers 113 - - 115 pivoted at 116 - - 118 and moved respectively by the direction control DC, permanently coupled to the rudder, the longitudinal control LC, and the lateral control TC. The control DV tilts the blades 97 and the ailerons 96, becoming inoperative during horizontal flight, the controls LK, LD progressively increase and decrease in effectiveness during the transition from vertical to horizontal flight, LK acting on the ailerons and LD on the lifting screw. The control TV acts also on the lifting screw and becomes inoperative during horizontal flight. Another link 119 from the lever VV is connected to the control OP for tilting the planes 93 and swinging the blades 97. A radiator 104 is arranged in an opening in the fuselage.