GB402956A - A cooling device for rapid fire weapons - Google Patents

Abstract

402,956. Machine guns. BAUMANN, W., 145, Boulevard Magenta, Paris. Jan. 30, 1933, Nos. 2850 and 2851. Convention dates, Jan. 29, 1932 and Jan. 14, 1933. [Class 92 (ii).] Relates to air cooling devices for machine guns and of the kind in which the gases following the projectile x, Fig. 1, expand through an ejector nozzle i at the gun muzzle and thereby induce a draught of cooling air through passages d formed between fins b on the barrel and a surrounding casing c. According to the invention, a muzzle-attachment is provided with an expansion chamber g and one or more ejector nozzles h opposite the muzzle, the arrangement being such that the speed of the gases in the ejector is reduced by their previous expansion in the chamber. In the form shown in Fig. 7, the device is shaped as a body of revolution about the gun's axis, the expansion chamber 6 being formed between the external casing 9 and a nozzle 8 forming an extension of the cooling casing 2. The gases reach the chamber 6 through lateral passages 5 behind the ejector nozzle 7. The cooling fins between the barrel 1 and the casing 2 may be formed by rings threaded on the barrel, each' ring comprising a sleeve 11 carrying radial fins 12 of the form shown in Fig. 10.