Patent GB-195371-A (GB)
Title: Improvements in apparatus for gun mounting laying and sighting for artillery on aeroplanes
IPC: F41G5/14
Filed: 1923-03-15
Abstract: 195,371. Schneider et Cie. March 25, 1922, [Convention date]. Sights and methods of sighting. - Means for mounting, laying, and sighting guns on aircraft in order to impart to the gun angular corrections relatively to the line of sight to take account of (1) tangent elevation corresponding to a given altitude of flight, and (2) longitudinal and transverse components o f wind, comprise in combination a gun-cradle F universally jointed to a frame D trainable on a horizontal ring d<1> concentric with the universal joint, and a sighting- device G which, although constantly directed on the target, is adjusted in elevation relatively to the gun by one cam mechanism H which imparts tangent elevation corresponding to altitude of flight at a given speed, and bv another cam mechanism K which gives the correction due to the longitudinal component of the wind W. In Fig. 17, N is the angle of sight from the gun A to the target B, the aircraft being assumed to fly at a constant height h and at a uniform speed v. # is the angle of tangent-elevation corresponding to the height h and speed v and # is the correction in elevation for wind. For a wind inclined at an angle # to the line of flight, the angle # corresponding to the longitudinal windcomponent W cos # is proportional to W cos # cos N, and the transverse wind-component W sin # gives rise to a traverse correction #. The gun mounting and sighting-apparatus are so arranged that, after a preliminary adjustment of the gun in azimuth to correct for the drift and the angle #, the operation of elevating the gun, keeping the target in view, automatically applies the corrections # and #. Fig. 2 shows the invention applied to a gun mounting as described in Specification 191,700, in which the gun cradle F is trunnioned at f in a support E itself mounted on horizontal trunnions e in the frame D which is adjusted for drift by a worm-gear d<5>. A wormgear f<2> serves to move the gun cradle about the trunnions f to impart the traverse correction #. The sight-bracket J, in which the bar I carrying the sighting-telescope G is spring mounted, is pivoted at e<2> to a bracket E<2>, Fig. 4, extending from the trunnion e, and is connected to the gun cradle by a link x. One end of the sight bar carries a pin G' bearing on the cam H which is adjusted along the trunnion axis to suit the flying height h and imparts, during the. elevation of the gun, the correction #. The other end of the bar I carries a pin I<1> bearing on the cam K which applies the correction # proportional to W cos # cos N. The cam K, which is rotated through the angle N by gearing H<4>, K<3>, K<2> to correct for the term cos N, is translated proportional to W cos # by setting a pointer j<4>, Fig. 6, to the appropriate # curve on a drum J<7>. The drum is previously rotated to set a scale for W against an index w. In a modification, shown in Figs. 10, 11, the eye-piece of the sighting- telescope is carried by a tube G<x> supported by a casing G fixed to a frame L which does not move when the gun is elevated on the trunnions e. When the gun is elevated, the cams H, E are rotated through a shaft n by gears N and P<3> and pins G<1>, I<1> bearing on the cams operate through differential and spur gearing to rotate the prism G<11> of the objective to apply the corrections # and #.