Patent GB-146488-A (GB)
Title: Improvements in and connected with fire control apparatus particularly intended for naval guns
IPC: F41G5/16
Filed: 1920-07-05
Abstract: 146,488. Krupp Akt.-Ges., F. March 19, 1917, [Convention date]. Gyroscopic apparatus for controlling or facilitating the operation of the firing mechanism of naval guns from an observing post. A stabilized sighting device is provided at the observing post electrically connected to a stabilized device at the gun mounting so that the controlled device is adjustable to correspond in elevation to the controlling device. In the form shown in Fig. 2, a telescope D' at the observing post is mounted on a shaft D stabilized by a gyroscope rotating on a vertical axis in a casing B carried in bearings on an arm p<4>, which is pivoted to a traversable pedestal mounting P<3> and is fast with a worm sector p<6> adjustable by a hand-wheel p<7>. A telescope J<1> at the gun mounting is similarly stabilized, and carried on an arm Q, which is loosely pivoted on the axis of the gun trunnion N<2> and is fast with a worm sector Q<1> adjustable from a hand-wheel r<1>. The two stabilized telescopes are connected by a Wheatstone-bridge device comprising at the observing post a resistance b<2>, over which moves a pointer d<2> rigid with the telescope D' and connected to the positive pole of a direct current supply, and at the gun mounting a similar arrangement h<1>, i<2> connected to the negative pole of tne supply, the ends of the resistances b<2> h<1> being connected through contacts m<2>, m<3> by wires M, M<1> bridged by a wire m‹ containing galvanometers m<4>, m<5>. The gyroscope casing 11 carries an electric contact and the outer gimbal ring of the gyroscope carries a co-operating contact, both being included in the firing circuit of the gun, and being adjustable to compensate for delay in firing. The sight D<1> is layed on the target or, if this is obscured by smoke, on any part of the horizon, and the sight J<1> is maintained at the same elevation as the sight D<1> by lateral pressure on the outer gimbal ring of the gyroscope, the correct adjustment being indicated by the absence of deflection in the galvanometer m<4>. When the gun has been elevated for range in the manner described hereunder, the firing switch is closed and the gun is fired when the subsequent roll of the ship brings the two aforementioned firing contacts together. The range elevation is transmitted from a distance to the pointers p<10>, p", r<4>, r<5> of range indicators at the observing post and at the gun, and the operation of the hand-wheels p<7>, r<1> geared to the indicators, until marks p<8>, p<9>, r<2> r<3> again register with their respective pointers serves to impart range elevation to the arms p<4> and Q. This does not disturb the balance of the bridge, because the resistances b<2>, h<1> will be equally displaced relatively to the stabilized pointers d<2>, i<2>. The gun is then elevated to the indicated range by operating its elevating gear; this movemnt rotates the arm Q carrying the gyroscope casing H because of the fact that the worm shaft bearing n<6> is rigidly connected to the gun trunnion N<2>; but this rotation does not disturb the balance of the bridge owing to the fact that the change in the ratio of the parts of the resistance h<1> on either side of the pointer j<2> is counteracted by an equal change in the ratio of the effective parts of resistances N, N<1> on the trunnion N<2>. A modification is described in which the sight J<1> is dispensed with, and the gyroscopic casing H is mounted directly on the gun trunnion. In another modification, the gyroscopic casing B is mounted directlv on the pedestal P<3>. Several guns may be controlled from one observing post.