Patent GB-476698-A (GB)
Title: Improvements in or relating to means for dispersing the fire of machine guns and thelike
IPC: F41A27/04
Filed: 1936-06-20
Abstract: 476,698. Gun mountings. HERBST, P. June 20, 1936, No. 17185. [Class 92 (i)] Machine guns, automatic guns, and anti-aircraft guns are oscillated automatically to spread the fire over a band or zone. The outer or cooling cylinder 1 of a machine gun may be pivoted at 4 in a cvlindrical frame constituted by four longitudinal bars 2 secured to the gun mounting, and the forward end of the cylinder 1 is coupled by a universal joint 11 to a connecting-rod 10 mounted on a crank-pin 9 which may be set at varying radii relatively to a drive shaft 5 by a rack-and-pinion gearing 12, 13 operated by a toothed push-rod 14 slidable within the shaft 5, the rod being held in set position by a catch 17. The shaft 5 may be driven independently or by means rendered operable by the firing of the gun. In the latter case, a pin 19, mounted in a part of the firing mechanism which reciprocates at each discharge, engages in a helical groove 20 in a sleeve 21, the rotary motion of the sleeve being transmitted through a one-way clutch to a collar 28 fast on the shaft 5. The clutch comprises a dog 31 mounted to be moved circumferentially by engagement with teeth in the sleeve 21, against the pressure of a circumferential spring 32, in a non-rotatable casing 33 urged axially by a spring 35. At the end of the advance movement of the pin 19, a buffer 44a thereon engages the casing 33 and removes the dog 31 from coupling engagement with the sleeve 21 and collar 28. The spring 32 thereupon returns the dog 31 to its initial angular position in contact with an adjustable stop 41. Rotary motion of the casing 33 while the clutch is disengaged, is prevented by the engagement of a projection 33a with an aperture in a collar 33b on the shaft 5. The sleeve 21 has a number of grooves 20 of different pitch, to impart various rates of oscillation to the gun and the stop 41 may be adjusted so that the dog 31 returns into alignment with the end of the selected groove 20 by freeing the pin 19 from the groove 20 and advancing the sleeve 33 until the stop 41 is clear of the bracket 44, the stop then being adjusted and allowed to return into the appropriate slot 43 in the bracket 44, which retains the stop against angular displacement. According to a modification, a part 45, Fig. 5, of the firing mechanism which reciprocates, carries a rack 46 which may be adjusted by a rod 49 having a member 48 adapted to engage with one of a number of notches 47 on the member 45, the adjustment of the rack predetermining the amount of rotation transmitted to a gear-wheel 50 coupled by a one-way clutch and spur and worm gearing to the shaft 5a. The setting of the crank-pin 9 determines the amplitude of the gun oscillations and the setting of the rack 46, or of the sleeve 21, Fig. 1, determines their frequency. The pin 19, Fig. 1, may be rendered inoperative by a lever 38 and the rack 46, Fig. 5, may be retracted so as not to operate the shaft driving the oscillating mechanism. The gun may be locked in central position within the frame 3, provided the crank-pin 9. is at zero radius, by a bar which is guided in the frame and has a head 23 provided with a T-slot engaging a pin 22 on the gun, the gun being locked when the shank of the T is in engagement with the pin. The frame 3 may be pivoted in a second frame about an axis perpendicular to the pin 4, the frame 3 then being oscillated by a similar mechanism so that oscillations of any type may be impressed on the gun.