GB153326A - Improvements relating to the aiming of anti-aircraft guns - Google Patents

Abstract

153,326. State of France. May 18, 1918, [Convention date]. Gunnery calculators.-In anti-aircraft gunnery, the gun corrections to be applied in respect of parallax at the observing station on account of drift and angle of site are ascertained by means of two coaxial and relatively-adjusted graduated sectors 14, 15 pivoted at r and moved automatically by connection with the gun through the cam 12 shaped to give movements proportional to log. tan S where S is the angle of site. The two sectors are relatively set by a pointer 16 positioned on sector 14 according to a scale of log. l (l being the length of the base) and set against a scale on sector 15 representing log. h (h being the altitude of the target). Pointers 18, 20 on sector 15 cooperate with curves drawn on disks 21, 22 which are connected with the gun so as to rotate in proportion to its azimuth. The curves on disk 22 give parallax due to displacement of the target and those on disk 22 give a quantity p's which by a further calculating-appliance (Fig. 2) may be converted into ps, the parallax in respect of the angle of site. In order to minimize the size of the disks 21, 22 auxiliary pointers 17, 19 spaced by a distance equivalent to log. 10 from the pointers 18, 20 may be employed and the necessary corrections made in the readings. The apparatus shown in Fig. 2 comprises a spindle d<1> connected with the gun so as to rotate through angles proportional to the angles of site and provided with a pinion gearing with a rack R terminating in a pointer I adapted to be set on a chart A inscribed with curves of p<1>s. A dial E<1> rotatable with the rack and pointer is graduated to show the resultant correction ps against a stationary index.