Patent GB-608044-A (GB)
Title: Aiming device for weapons intended for use against moving targets, particularly aircraft
IPC: F41G5/08
Filed: 1945-08-30
Abstract: 608,044. Gun-sights. GERBER, A. Aug. 30, 1945, No. 22410. [Class 92 (ii)] A sight, particularly for anti-aircraft guns, includes a combination of members which form a triangle similar to the aim-off triangle in space, these members being so mounted that the reproduced triangle rotates about one of its sides which is of fixed length and being connected (a) to a straight line aiming mark in such manner that the target as viewed through the field of view of a telescopic sight appears to move along the mark, and (b) to an additional aiming mark, movable along the first, so that alignment of the target with such mark results in the correct aiming-off angle being applied to the gun barrel. To effect the correct movement of the second-mentioned aiming mark the members of the triangle are suitably connected to range and target-speed setting means. General layout.-As seen in Fig. 1, a guncarriage 2 is rotated in azimuth on a support 1 by rotation of a hand-wheel 7, and on the carriage is mounted for elevational movements the cradle 4 of the gun 3; 8 indicates the elevation hand-wheel. To the support is connected a rigid arm 11 which, with the upper ends of rods 12 pivoted to the cradle 4, supports a plate 13 for the sight 14 in such manner that the plate 13 is maintained parallel to the axis of the gun-barrel. Construction.-The arm 11 is provided with arms 21, Fig. 2, which carry a fixed axle 22 on which the plate 13 is pivoted. On the axle 22 is pivoted a casing 14 which is fitted with a holder 30 for the lenses of the sighting system and with a translucent silvered glass plate 28, through which the target is viewed and on to which is projected images of the aiming-off marks by means of a lamp 34. A yoke 39 is pivotally supported between frame members 35, 35, of the casing 14 and is maintained in a vertical position by links 40, 41, 42, connecting its shaft 38 with the axle 22. The yoke carries a disk 45 which remains always horizontal and which can be rotated either by a handle 59, for initial setting, or by a shaft 61 geared to the gun-training mechanism in such manner that any given diameter on it remains in the same position in space while the gun is being trained. The disk carries a slidable rack 65 whose outer end is connected by a universal joint to a telescopic rod 68, whose socket 69 is fixed to an axle 71 which is turnable in a yoke 70. Gears 75, 78, associated respectively with the pin and yoke serve to rotate shafts 77, 76, which in turn serve to rotate a pair of rings associated with the aiming marks in the casing 30. In use the rod 68 is carried round the surface of an oblique cone whose base is defined by the disk 45 and the apex by the intersection of rod 68 and axle 71, the rod 68 in being thus carried serving to impart, by shafts 76 and 77, the required movements to the aiming-off marks. The rack, the rod 68 and the slant axis of the oblique cone form the members of the aim-off triangle. The effective length of the rack is proportional to the product of the speed of target and the time of flight, and to produce the required length the rack is moved, through suitable differentials 142, 145, by gearing leading from a multiplying device. The time of flight is set in to this device by a handle 112 adjacent a range scale, which handle serves to move the block 128 carrying the pivot of a lever 130, one end of which is moved by a nut 131 in accordance with the targets speed as set in by a handcrank 125. The other end of the lever thus gives the required product and serves to move a rack 132 to which the rack 65 is geared. The range handle 112 also serves to translate a cam 119 on a shaft 111 which shaft is rotated, on change of elevation, by the shaft 38, the cam engaging a roller on a rod 15 whose lower end rests on a part 25 of plate ; by this means the sighting mechanism has imparted to it a pivotal movement about the axle 22 to provide the superelevation correction. Aiming marks.-One of the rings in the housing 30 holds a lens whose flat surface is opaque but for a pair of slightly spaced diametrical lines, which in use are positionedby rotating the crank 59- so that the target moves along the images of the lines as seen in the mirror 28. When such a condition exists the rack 65, Fig. 2, lies in a direction parallel to the intersection of the plane of flight with the horizontal. Also on the ring is a pair of plates 90, Fig. 3, fitted with rollers 93, 94 and a tape 95 passing around these rollers has its ends fixed at 96 on the other ring in the housing. When therefore the disk 45 or the rack 65, Fig. 2, move and motion is imparted to the shafts 76, 77, relative rotation occurs between the two rings in the housing 30, and the tape 95 moves with respect to the rollers carrying with it the aiming mark 99 which is fixed to the tape.