Patent GB-191211946-A (GB)
Title: Improvements in Sighting Apparatus for Ordnance.
Inventor: BACON REGINALD HUGH SPENCER
Filed: 1912-05-20
Granted: 1913-05-08
Abstract: 11,946. Bacon, R. H. S., and Redpath, R. May 20. Naval and garrison carriages and mountings.-Relates to mountings of the type described in Specification 5903/12 for guns used against rapidly-moving targets. According to the invention, means are provided whereby the operations of finding the range and of elevating and training the gun to keep the line of sight directed constantly upon the target automatically produce the required corrections for the range and the speed of the target. In the form shown in rear view in Fig. 4, a rangefinder 1 of the usual coincidence type, carrying sighting - telescopes 13, 14 is mounted on a pivot 29 on a casing 2 capable of turning on trunnions 3 co-axial with the trunnions 5 of a frame 4, which is caused, by a parallelmotion device, to be elevated at the same rate as the gun. The elevating and training gears are actuated by hydraulic motors driven respectively by pumps 17, 23, and the speeds of elevating and training are regulated by separate observers' operating hand-wheels 26, 27 so that the sights are kept constantly on the target. The observer actuating the wheel 26 determines the range by setting the hand-wheel 28 of the range-finder; the motion of this wheel is communicated through bevel-gearing to a shaft 31, which rotates, through suitable gearing, (a) a range-cam 341 mounted in the casing 2, Fig. 14, and bearing on a projection 47 carried by the frame 4, thereby producing in the casing 2 carrying the sights a rotation relatively to the frame 4 and therefore to the gun, equal to the tangent angle of elevations; and (b) a grooved piece 36, shown in the horizontal section in Fig. 8, in which engages a projection 46 of a plate 40 adapted to slide in a direction parallel to the axis of the trunnions 3, in a frame 37 capable of being traversed on guides 38 by a hand-wheel 26. A second plate 39 sliding in a similar manner in the frame 37 carries a projection 43 engaging a suitably inclined groove in a piece 42 fixed to the casing 2, and, as the frame 37 is traversed, actuates a rod 45 which regulates the speed of the elevating-motor of the gun. The traverse of the frame 37 is therefore proportional to the speed of elevation of the target, while the rotation of the piece 36 is proportional to the time of flight of the projectile; the displacement of the slide 40 is proportional to both these displacements and therefore to the deflexion of the gun necessary to correct for the speed of elevation of the target. The motion of the slide 40 is imparted through a member 461, to the rangecam 341, Fig. 14, and communicates to the sighting-line the requisite deflexion for speed of target in elevation. To correct for the azimuthal speed of the target, the motion of the shaft 31 is combined in a similar manner, as shown in Fig. 8, with the traverse of a frame controlled by the hand-wheel 27 which governs the speed of the training-motor. In this case, the sliding plate 57 directly actuates the range - finder through a bell-crank lever 30, Figs. 4 and 8, and imparts to the sighting-line the necessary azimuthal deflexion. Means are also provided whereby, as the angle of sight # of the target increases, the rate of training of the gun round its vertical pivot for a given speed of target is made automatically to vary inversely as cos #. To effect this, the end 65 of the rod 55, which communicates the motion of the sliding plate 54 to the training-motor, actuates the regulating- gear of the training-motor through a quadrantal lever 25, shown in the side view in Fig. 10, this lever being journaled at 62, 63 to a stationary bracket 6. The end 65 assumes different positions in the circular guide 25<1> at different elevations of the casing 2 and produces a rotation of the regulating-lever 25 varying inversely as cos #. The tangent angle of elevation set off by the range-cam 341 is automatically decreased, as the angle of site increases, by adapting the cam to be displaced uniformly in an axial direction against the action of a spring as the frame 4 is elevated, and suitably shaping the cam-surface. A modified form of apparatus is described in which the range-finder is vertical at zero elevation of the gun. The line of sight may, in all cases, be arranged below the normal level of the underside of the gun chase.