Patent GB-190420069-A (GB)
Title: Improvements in and relating to Sights for Ordnance
Inventor: SCOTT LOTHIAN KERR
Filed: 1904-09-17
Granted: 1905-07-13
Abstract: 20,069. Scott, L. K. Sept. 17. Sights and methods of sighting. - Relates to improvements in automatic sights of the kind described in Specification No. 25,585, A.D. 1901, and is shown as applied to disappearing-gun mounts, Fig. 1 being a side elevation and Fig. 2 an end elevation. The sight 1 is carried by an arm 2 pivoted to a bar 3 pivoted in turn at 11 between the arms of a forked bar 4. The bar 4 is hinged by trunnions between the arms 13 of a standard fixed to the carriage, and is caused by the rod 12, 12<a> of a parallel motion device to remain parallel to the axis of the gun in any position of the latter. The bar 3 has a depending arm carrying at its extremity the cam-curve frame 3*, in which may be mounted one or more cam-curve blades 41, cut for varying heights of tide, and error of day and other corrections, such as speed of target multiplied by time of flight. The blade in use is pressed against a roller 28 mounted on an arm 28<a>, carried by a vertical spindle 15 which may be raised or lowered by the lever mechanism 18, 19, 20, 21, by the motion of the rod 12, 12<a>, or directly from the elevating-gear of the gun, so that a large relative motion of the blade 41 and roller 28 is obtained for a small change in elavation of the gun. The angle of elevation of the gun is indicated by a vernier v on the bar 4 reading against a scale 13<a> on the standard 13, and the angle between the gun and line of sight is indicated by a second vernier 6 on the bar 3 reading against a scale on the bar 4. To change from automatic to ordinary sighting, the bars 3, 4 are brought parallel to one another and then clamped by the screw 8, the roller 28 having been removed from the camcurve. To raise the point of impact on a stationary target, the gun is first laid by the automatic sight, the roller 28 is put out of action, and the bars 3, 4 are clamped by the clamp 7 ; the sight is then used as an ordinary sight for the additional elevation required. Fig. 8 shows a cam-curve frame 3 arranged to receive a number of blades 41. The blades are secured in radial slots in collars c, on a drum 32 mounted on a spindle 31, by means of pins 42 and notches 43 over which a cap 33 is secured by a screwed collar 34. A spherical joint 29 at the lower end of the spindle 31 and a swivel 36 at the upper end allow of the adjustment of the drum 32 and blades by the screws 27. The swivel 36 has an extension on which is a pin 37 to be engaged with any one of a series of holes in a disc 38 ; each hole corresponds to one of the blades 41 and is marked accordingly. If desired, a single blade may be employed, and both the blade and frame may be adjustable to allow of two separate adjustments being made for different corrections. The blades may be finished in sit¹ to the exact curvature required by providing a milling-cutter of the same diameter and on the same spindle as the roller 28, driving-mechanism for the cutter being provided ; or the roller 28 may be replaced by a graver so that the correct curvature is marked on the blade by a number of points, the blade being filed down to the marks.