GB569463A - Improvements in apparatus for use in the directing of anti-aircraft fire - Google Patents

Abstract

569,463. Anti - aircraft gun - fire directors. MAY, W. J. Jan. 2, 1941, No. 65. [Class 92 (ii)] The director comprises a transparent overhead panel P marked with graduated outer and inner rings O, I and having adjacent thereto adjustable bars A ... E giving relative adjustments to a back-sight 7 and a fore-sight F<1> for wind, speed of target and altitude after the manner of the usual bombing sights that require a downward view instead of an upward view as in the present instance. The adjustable bars include a diametral back-sight carrying member A, a target line of flight arm, B movable across the rings, and a line of fire member E pivoted at 22 to the member B and rotatable about the centre of the rings by movements of the arm B. The arm B is first set on a guide ring 2 to show the line of flight of the target as it enters the outer ring in the direction of the arrow. The known data, height, air speed and heading of the target, and the speed and direction of the wind is then set up to enable the target to be attacked as it leaves the inner ring. The ground speed is given on the graduated arm A after the bar C has been adjusted for wind and the bar D for airspeed. The arm A is then set parallel to the arm B. The back-sight 7 is adjusted on scale 6 for height, a minor adjustment for site being made by a knob 12. The foresight F<1> is adjusted on the arm B for time of flight of the shell. The arm E indicates the direction of fire for the gun which is set in elevation to cause a burst on the circumference of the inner ring.