GB441687A - Improvements in devices for cooling the barrels of quick firing guns - Google Patents

Abstract

441,687. Machine guns. BAUMANN, W., 145, Boulevard Magenta, Paris. July 18, 1934, No. 21067. Convention date, July 18, 1933. [Class 92 (ii)] In a device for cooling the barrel of a machine-gun, of the kind described in Specification 402,956 in which the explosion gases are passed through an ejector to induce an air-flow along a jacket surrounding the barrel, the expansion of the gases is carried out in stages by passage through a series of chambers or the successive compartments of a single chamber. As shown in Fig. 1<a>, applied to a fixed-barrel type of gun, the expansion-chamber 2 fitted to the muzzle of the barrel 1 is divided by a perforated partition 8 into two compartments 6, 7, the latter being fitted with one or more ejectornozzles 3, 10 by means of which air is drawn into the casing 4 through passages 5 in a jacket surrounding the barrel. The chamber 6 may be divided as by a partition 9 in which case the subsidiary chamber 6a may be fitted with auxiliary ejectors 11. The spent gases from the gun-operating cylinder 14 may be passed through a pipe 15 to additional ejectors 16 in the casing 4. The cooling-jacket may be built-up as a series of rings formed of a light alloy of good heat-conductivity, such as aluminium and silver. Fig. 6 shows the application to a gun having a movable barrel 1 which is spaced from the cooling-jacket 5, the space 30 being packed with heat-conducting material in the form of powder or filings of copper, silver, &c. In this construction, a collar 31 fitted to the muzzle-end of the expansion-chamber 2 is formed with labyrinth grooves 32 to impede back-flow of the explosion-gases. The barrel, and the bore of the jacket, may be of polygonal or other non-circular section ; and, the jacket may be built-up of sector-shaped pieces instead of rings.