Patent GB-191421252-A (GB)
Title: Improvements in Adjusting Means for Machine-guns or the like.
Inventor: SJOEQVIST DAVID GUSTAV
IPC: F41A27/06
Filed: 1914-10-20
Granted: 1915-07-01
Abstract: 21,252. Sj÷qvist, D. G. Oct. 20. Field carriages; mounting and dismounting. -Relates to elevating and training gears for machine guns and of the kind in which the elevation of the gun is automatically adjusted while the gun is reciprocated to sweep an oblique target from one end to the other, the automatic adjustment being performed by a guide, which is set at a correct obliquity by aiming the gun at two separate points of the target. According to this invention, the guide is not connected directly to the gun barrel as heretofore, but through the medium of a mechanism such as a parallelogram motion. whereby the construction is simplified, the aim more accurate, and the gun barrel made easily detachable. In the form shown in Figs. 1 and 2, the barrel is carried by a cradle 18 by means of lugs fitting in forks 20, and another lug detachably held in a hole 22 in a rotary bolt 21. The cradle 18 swings on bearings 17 carried by arms 16 from a vertical ring 13 rotatably mounted within a ring 1, which is connected by arms 2 to bearings 3 carried in trunnions on the gun carriage, and provided with an elevating-arc 4 having a locking-device. Around the ring 1, there is another ring 5 provided with a lock 19 and made in one with an horizontal ring 6, within which is rotatably mounted a cup-shaped member 7 provided internally with parallel guides 9, a small part 7<1> of the cup being split from the rest and provided with a screw 31, the point of which fits into a hole in the ma:n part 7, so that when the screw is screwed in, the part 7<1> is drawn away from the main part 7 and the whole is tightened in the set position within the ring 6. A tubular arm 10 passing between the guides 9 and through a transverse slot 26 in the cup 7 is pivoted at one end C to lugs 12 projecting from the innermost vertical ring 13, and at the other end by means of a lug 24 to a link 23, which is itself pivoted to the cradle 18, so that a parallelogram motion A, B, C, D is formed, ensuring that the gun barrel carried by the cradle shall follow the training and elevation of the arm 10 as determined by the guide 9. A spring plunger 32 within the arm 10 is connected by a cross-pin 37 to a sleeve 38 adapted to be forced by the spring 33 into a central circular enlargement of the slot 26 in the cup 7, so as normally to lock the arm 10 in the central position. The plunger is coupled to a handle 36, which can be pulled out and then turned to unlock the arm 10 and to retain the sleeve 38 in the unlocking position. In use, the gun is first aimed correctly at the centre of the target, while the lock 19 is released and the arm 10 is locked in the central position, the elevation taking place about the trunnions 3, and the ring 5 following the training rotation of the ring 13 relatively to the ring 1. Next, the elevating-arc 4 is locked, the lock 19 is operated to lock the ring 5 to the ring 1, and the screw 31 is unscrewed to loosen the cup 7 ; then the gun is aimed at one end of the mark, but now the elevation takes place about the bearings 17, and the arm 10, in following the aim of the gun, slides to one side of the guide 9 and causes the cup 7 to rotate until the guides occupy the correct inclination for the target. Finally, the screw 31 is screwed in to tighten the cup 7 in the ring 6, and the gun is ready to be fired, being automatically guided to the correct elevation by the guide 9 and the parallelogram motion when reciprocated to sweep the target from one end to the other, the handle 36 serving as a convenient means for manipulating the gun. The cradle 18 may be dispensed with, the gun barrel being then attached directly to the mounting.