Patent GB-226496-A (GB)
Abstract: 226,496. Schneider et Cie. Dec. 18, 1923, [Convention date]. Gunnery calculating-apparatus.-A corrector for firing from a ship at an objective on land or at sea and for solving in a continuous manner the equations giving the bearing and quadrant elevation of the gun for the predicted relative position of the objective, comprises two Wheatstone bridges, the maintaining at zero of the voltmeters of which gives in the one case the wind correction for direction, and in the other case the wind correction for elevation. The following notation is use :-G = the bearing of the gun ; g = the bearing of the line of sight; c = the direction of the firing ship's head; T = the time of flight for the predicted relative position of the objective ; #w (g) = the wind correction for direction; #w (s) = the wind correction for elevation ; W = the wind's speed ; I = the quadrant elevation of the gun for the predicted relative position of the objective; s = the site angle ; H = the tangent elevation of the gun for the predicted relative position of the objective; # = the azimuth of the line of sight and is equal to (g + c) ; # = the azimuth of the wind's direction; and gamma2 = the muzzle velocity. g and s are transmitted from the sighting telescope and T and H from a distance by a calculator of future tangent elevations, while c is indicated by a gyroscopic member. # w (g) and #w (s) are given by the equations :- The invention solves equations (3) and (4) in a continuous manner. An axle 1 turning proportionally to the bearing g drives, through transmission 9-8-7-6-5 a tachometer 4 which also receives the value for T from axle 10 operated by a known calculator of distances and times of flight. The planet wheels 11 of the differential 2, dg 3 therefore turn proportionally to g + T -. dt # w (g) is given by the first Wheatstone bridge A. B, C, D receiving current at B and C and comprising :-(1.) A resistance 22 regulated by a contact 21 rotated from the shaft 18 as a function of W ; (2.) A resistance 23 regulated by a contact 24 rotated by shafts 80, 75, 77, and 26 as a function of I; (3.) A resistance 27 regulated by a contact 28 driven as a function of # - # from the differential 30, 31, 42 of which the wheel 31 is driven from the differential 33, 34, 36 as a function of # and the wheel 42 is driven from the hand dial 45 as a function of # ; and (4.) A resistance 101 regulated by a contact 102 driven by a handle 104 which is operated by a gunner to keep the voltmeter E at zero. With a suitable regulation of these resistance we have resistance 101 _ K W and hence from sin # - #) cos I equation (1) above resistance 101=K. Vo. #w (g) and since Vo is constant the handle 104 turns as a function of #w (g). This rotation is transmitted to the wheel 14 of a differential of which the other wheel 13 is driven from the differential dg 2, 3, 11 as a function of g + T -. The wheels dt 15, 16 and shaft 17 therefore turn as a function of #w (g) + g + T - = G from equation 3 above. The site angle s is transmitted to the shaft 46 and thence to the tachometer 50 and to the wheel 47 of a differential, the other wheel 48 ds of which turns as a function of T -. The wheels dt ds 55 and 57 therefore turn as a function of s + T-. dt # w (s) is given by a second Wheatstone bridge P, Q, R, S comprising :-(5.) A resistance 67 varied by the contact 68 and shaft 70 as a function of W ; (6.) A resistance 71 varied by a contact 72, shafts 80, 75 and cam 74 as a function of I; (7) A resistance 82 regulated as a function of # - # by the mechanism 84. 86. 88, 90, 92, and 94; and (8.) A resistance 95 regulated through three differentials, 47, 48, 55-57, 58, 60-62, 63, ds 64 as a function of s + T- + H + p w (s) = I from dt equation (4) above. The handle 98 regulated to keep the voltmeter Z at zero therefore turns as a function of #w (s), the wind correction for elevation.