GB545587A - Improvements in and relating to apparatus applicable to screw propellors for obtaining maximum efficiency under all conditions - Google Patents

Abstract

545,587. Screw propellers, fans and the like. ADAMTCHIK, M. T., and KENNEDY, J. R. Feb. 4, 1941, No. 1497. [Class 114] [Also in Group XXVI] For directing the flow of fluid on to the propelling or impelling blades of a marine or air craft, pump, fan or turbine, a number of flexible vanes, which are variable both in pitch and in camber, is pivotally mounted on axes that are stationary relative to the propelling or impelling blades, enabling the vanes to be set either at a positive or negative angle to the general direction of flow of the fluid. In the construction shown in Fig. 1, in which the vanes 9 are supported between a boss I and an outer casing 3 so as to be applied as a self-contained unit to the aircraft or engine frame in advance of the propeller hub 24 and blades 4, each vane.is carried by a sleeve 8 rotatable upon a shaft 7 extending between the boss 1 and casing 3, and.is also connected to a second shaft 12 from which extends a guide pin 17, while a sleeve 18 surrounding the shaft is provided with a guide pin 19 at its inner end. The guide pins 17, 19 and a third guide pin 16 attached by a lever 14, Fig. 4, to the shaft 8 engage slots 20, 21, 22 in a sliding control plate 23, Fig. 3, the inclination of the slots being so arranged that, as the plate 23 is displaced in either direction from its mid position, the vanes 9 are swung to a positive or negative angle and at the same time are flexed to a curved form as shown in the extreme positions in Fig. 5. Preferably, the number of vanes 9 differs from the number of propeller blades 4, while the sliding plates 23 controlling the vanes are simultaneously operated. In a modification, Fig. 8,. in which the vanes 29 are associated with the blades 42 of an impeller fan or pump, and are secured to shafts 28, simultaneous adjustment of the vanes is effected by means of a rotatable ring 41 connected to levers 35 which are engaged by pins 33 depending from ball joints 32 disposed at the inner ends of the shaft 31 that determine the pitch and camber of the vanes 29.