GB141392A - Improvements in or relating to ordnance sighting apparatus - Google Patents

Abstract

141,392. Dawson, Sir A. T., and Buckham, Sir G. T. Oct. 10, 1918. Sights.-Relates to guns not having an independent line of sight, and consists in actuating the sight by a hand-wheel, or other member fixed on the gun carriage, through mechanism forming a positive drive of shafts and gear-wheels from which all universal joints are eliminated, so that the setting of the sight is independent of the movement of the gun in elevation. In the form shown in Fig. 1, the sight-bracket C, pivoted coaxially with the gun trunnions, is adapted to be elevated by a pinion C<3> mounted on the gun cradle and driven from a hand-wheel E mounted in a fixed position on the gun carriage A, through gearing comprising a shaft E<1> and a worm E<2> meshing with a worm-wheel mounted on a shaft carried by a bracket E<4x> on the gun carriage, the latter shaft also carrying a bevel wheel E<3> meshing with a bevel-wheel e<3> connected through a telescopic drive-shaft e<5> with bevel-gearing e<4>, E<4> connected to the sight-elevating pinion C'. The bevel-wheels are all equal in size, and the distances between the axis C<1> and the axes of the bevel-wheels E<3>, E<4> are equal, so that any movement of the gun in elevation will not disturb the angular relation of the pinion C<3> to the line joining it to the pivot C<1>, and will therefore not affect the setting of the sight. Two such devices may be employed, one for range and the other for vertical deflexion. A similar device, an example of which is described, may be employed for horizontal deflexion.