GB574117A - - Google Patents

Abstract

574,117. Aircraft gun sights. BRISTOL AEROPLANE CO., Ltd., FONSECA. E. C. M. D'ASSIS-, and GREEN, S. Jan. 6, 1944, No. 286. [Class 92 (ii)] Relates to sights for guns mounted on aircraft of the kind in which the angle between the gun 1 and the sight 2 is corrected for the forward speed of the aircraft. According to the invention, a member is kept parallel to the axis of the gun and a second member is kept parallel to the sight line, the angle between the members being adjusted by a single control for both '' own speed " and the change in attitude of the aircraft consequent on the change in " own speed." As shown, a parallel-motion linkage 6 is connected between the gun 1 and a first member 10 moving on a pivot 11 on the fixed frame 3, and a parallel-motion linkage 5 is connected between the sight 2 and a second member 13 moving on a pivot 14. The members 10, 13 are slotted and pivotally connected by a cross-head 18 which is adjustable by a handle 23, flexible shaft 22 and screw 20 to adjust the angle between the members to vary the projectile vector-triangle 11, 14, 18. The side 10 of this triangle represents the projectile muzzle velocity, the side 24 the forward speed of the aircraft, and the side 13 the resultant velocity of the projectile along the line of sight to the target. In adjusting the cross-head 18, simultaneous adjustment of the direction of the side 24 is made by worm 32, sector 31, link 30, roller 33, cam 34 and bell-crank 29, 24. The movement thereby conveyed to the arm 13 corrects the sight line for the speed and attitude of the aircraft.