544,617. Rotary propellers, engines and pumps. STEVENS, A. T. Aug. 12, 1940, No. 12847. [Class 4] [Also in Group XXVI] A device for use as a lifting or sustaining device for an aircraft or as the rotating part of a prime mover, pump, blower or current motor, comprises two members, each having two flat surfaces fixed at an angle to one another, hinged along their ridge lines or a line parallel to them, the hinge line or lines being rotated about a shaft at right angles thereto and gearing being provided to oscillate the members about the hinge line or lines to cause each pair of opposed surfaces to execute one complete approaching and receding movement for each revolution of the shaft. For use in a prime mover, pump or blower the device is enclosed in a spherical or part spherical casing provided with inlet and outlet. The two members having flat surfaces 10, 11 are hinged about a divided shaft at the ridge line of which the two parts extend from a central ring 14. The ring 14 is bolted to a tubular driving shaft 15 surrounding a fixed shaft 17. Mounted to rotate with the shaft 15 and at right angles to both the ridge line and the shaft 15 is a guide for a moving balanceweight 24 which is reciprocated by gearing contained in an arm 19 fixed to the shaft 17 so as to preserve the balance of the members as they oscillate. Attached to the ends of the balance-weight 24 are cables 25 .. 28 which pass over pulleys 52 on extensions 60 of the guide and are secured to the surfaces 10, 11 in pairs so that the oscillation of the members about the ridge line is effected by these cables. A spherical casing 61 fixed to the ring 14 encloses the mechanism and has openings 62 for the passage of the weight 24. Fig. 1 shows a cross-section of the mechansim within the casing. The tubular shaft 15 is in two aligned parts 15, 16 having bearings on two aligned shafts 17, 18 of which the latter is secured to a frame 130, Fig. 4, fixed to the aircraft. The shaft 17 is normally fixed but is rotatable at will to vary the direction of thrust of the device by altering the phase of the oscillating members. The casing 19 is keyed to the shaft 17 and contains gearing 42, 43, 44 to cause a shaft 31 to make two revolutions to each revolution of the shaft 15 to which the innermost gear wheel 42 is keyed. The shaft 21 carries an arm 22 the outer end of which engages a stud 23 on the balance weight 24. The weight 24 is grooved to run on pulleys 31 on a member 30 fixed to the tubular shaft 16 which is secured to the ring 14. The extension 60 on this member 30 are of cruciform section. The whole apparatus is enclosed in an open framework 131, Fig. 4, secured to the frame 130, and carries a circumferential part spherical band, not shown, one third the depth of the apparatus to prevent lateral flow of air. For use as a prime mover two such devices are mounted on a common shaft within two spherical casings Fig. 6. The common shaft 70 has circular enlargements 70<SP>1</SP> surrounding the angle members which are set with their pairs of ridge lines in planes at right angles. The angle members are separated by discs 76 at right angles to the common shaft. Inlet ports are arranged on the upper parts of the casing and outlet ports on the lower part. For use as a pump a similar device including the disc 76 is enclosed in a single part spherical casing within a tube and the tubular shaft provided with means for driving it. Fig. 8 shows a modified device adapted for circulating fluid in a conduit or for use as a current motor. Two sections of spheres pivoted to oscillate about a common ridge line 107 rotate within a part-spherical casing 110 about an axle 106. Balls 120 in the casing co-operate with grooves 122 in the sectors to cause the oscillation of the sectors as the shaft is rotated slots being formed in the sectors to clear the shaft 106. The outer part of the casing 110 is cylindrical to fit the conduit.