Patent GB-190125585-A (GB)
Title: Improvements in and relating to Sights for Ordnance.
Inventor: SCOTT LOTHIAN KERR
Filed: 1901-12-14
Granted: 1902-05-01
Abstract: 25,585. Scott, L. K. Dec. 14. Sights and methods of sighting.-Relates to improvements on the automatic sighting-devices described in Specifications No. 159, A.D. 1894, and No. 7584, A.D. 1898, according to which all that need be done, when laying the gun, is to bring the line of sight upon the target, no matter what the range may be, the sight, when moved with the gun, effecting automatically the adjustment required for range, provided an initial adjustment is properly made. Fig. 1 shows one form of the invention as applied to a disappearing gun. The telescope sight 1 is carried by the range curve frame or sight-bar 2, pivoted at 3 to a bracket 4, which is pivoted at 5 to a standard 6 fixed to the floor of the revolving platform or turret, or some part of the gun carriage which moves in a horizontal plane with the gun. The screws 9, 10 on the standard 6 are for levelling the bracket 4, for adjusting the sight, and for correcting for fore and aft dip in the gun platform. A clinometer level 11 is also provided. The range curve frame 2 has a graduated projecting piece 12, which slides in a graduated groove 13 in the bracket 4 and is provided with a clamping-screw 14. The frame 2 may be employed, as thown on the right-hand side, with a range curve 15 adjustable by a number of double - acting screws 36, as described in Specification No. 7584, A.D. 1898, or, as shown on the left-hand side, an interchangeable rigid curve 17 may be provided. The frame 2 has extensions 16 to receive the range curve, and screws 24 adjust the curve for errors of the day, that is, for errors due to the quality of the powder and for "fore and aft" wind correction. The sight lever 25 is pivoted at 5 to the standard 6, and its long arm carries a roller 26, which moves along the underside of the range curve, while its short arm is connected by an adjustable screw coupling 27 to the rod 27<a> pivoted to the gun elevating-gear block 28. The elevating-arm 28<a> is pivoted to the block 28, which slides in the groove 28<b> to elevate or depress the gun. The lever 25 carries a vernier block 30, which travels in a groove 29 on the bracket 4, the groove being graduated at the top for elevation and at the bottom for range. An ordinary telescope gun sight 31 may also be mounted on the apparatus, to give the correction for lateral inequalities of the gun platform. The sight 1 is pivoted at 32, and has an extension 32<a> having a drift curve or cam 34 held against a stationary pin 32<b> on the bracket 4. A spring 33 holds the drift curve against the pin, and the screw 35 makes the necessary horizontal corrections for wind and speed of moving target. In modifications, (1) the range curve is attached to the frame 2 by eccentric cross-pins, which are rotated for tidal corrections ; (2) a number of superposed range curves are carried on the frame 2, and the roller 26 is mounted on the lever 25 so as to be readily brought under any particular range curve ; (3) when the gun platform is absolutely level, the short arm of the lever 25 is weighted so as to keep it in. contact with the gun without being actually connected thereto ; (4), also, when the gun platform is absolutely level, the lever 25 is dispensed with, and the sight bar 2<a>, Fig. 11<c>, is pivoted at 5<a> to the standard 6 and carries the range curve 4<a>, which bears directly on the roller 25<b> on the elevating-gear block 28 of the disappearing gun ; and, (5), the gun trunnion 51, Fig. 12, carries an arm 57 provided with elevating- gear 59, which is mounted on a second arm 55, loosely pivoted to the trunnion 51 and provided with elevating-gear 53, which in its turn is mounted on a bracket 52 of the gun carriage, so that, when the screw 53 is turned, the gun and sight move en bloc, and, when the screw 29 is turned, the lower member of the arm 57 moves the lever 60 to operate the sight 1 automatically, either by the apparatus shown, or by adapting the apparatus shown in Fig. 11<c>.