Patent GB-189807584-A (GB)
Title: Improvements in and relating to Automatic Sighting Apparatus for Ordnance.
Inventor: SCOTT LOTHIAN KERR
Filed: 1898-03-29
Granted: 1898-12-23
Abstract: 7584. Scott, L. K. March 29. Range - finders. - Consists of improvements on the invention described in Specification No. 159, A.D. 1894, and includes duplex elevating - gear; Figs. 1 and 2, so that automatic sight elevating- gear or ordinary elevating-gear may be employed ; an adjustable range curve, Fig. 7 ; and brackets, Figs. 8 and 9, for carrying the range curve when it is to be employed as a rangefinder and as a director. In Figs. 1 and 2 the duplex elevating-gear is shown as fitted to a field carriage. The gun A is carried by trunnions a in the fork of the bracket B, which is fixed to the arm b. This arm is passed at its front end through the axle-tree b<1>, so as to be free to turn therein, and is supported at its rear end by the ordinary elevating-gear s<4> on the trail T. A second elevating-gear s<2> is carried on the arm b, but as this gear is operated it communicates motion through the wheels h<4>, h<3>, h<1>, h to the shaft D, which is carried by brackets C, C' on the gun and is provided with a traveller G which in its rearward movement raises the pivoted range curve frame E carrying the sight bar or telescope F. The arm b can be rotated for the purpose of making the sights vertical by a transverse screw t<5> which operates a curved rack t connected to the arm b. A clinometer R and cross-level R' are fitted to the arm b. In modifications, (1) the transverse adjusting-screw is applied to the arm b at a part which projects beyond the bearing b<2> of the ordinary elevating-gear ; (2) the gun is arranged to recoil in a cradle, in which case the sighting-apparatus is attached to the cradle ; (3) the automatic sight-elevating gear is attached to the upper end of the screw of the ordinary elevating-gear, the horizontal disc of the wheel of the automatic gear being provided with an upper cam surface which acts upon the ordinary tangent sight of the gun ; (4) the traveller is moved by the gearing shown in Specification No. 159, A.D. 1894, the train of wheels being operated by an arm which joins the two kinds of elevating- gear. The range curve is shown in Fig. 7, and consists of a hollow frame E through which a number of teeth e' are arranged to be pushed by screws e<8> so as to press on the thin plate e' to vary the curve over which the traveller G moves. The top nuts L are graduated for tide allowances, and the teeth e<1> are graduated for corrections due to the variable strength of powder, the wind, and the speed of the target in the direction of the line of fire. The range scale m may also be made adjustable to enable corrections to be made. The range curve may be elevated by the end tooth e<3> when ordinary sighting is required, or the screw e<10> may be employed for ordinary sighting. When the range curve is employed as a range-finder or as a director, it is carried on special apparatus, Figs. 8 and 9. The range curve is mounted on the brackets C, C or plates p<1>, p<1>, one of which has a projection p<2> for engagement by the screws p<3>, p<4> to enable the range curve to be depressed for the necessary tide allowance shown on the clinometer R. The plates p<1>, p<1> move in plates p, p which are carried on trunnions and are adjusted in a vertical plane by the screw p<5>.