GB516411A - Improvements in driving bands for projectiles - Google Patents

Abstract

516,411. Making driving-bands for projectiles. SCHNEIDER & CIE. April 6, 1939, No. 10815. Convention date, May 3, 1938. [Classes 83 (ii) and 83 (iv)] [Also in Group XXI] Altering physical structure.-In making and applying driving bands for projectiles a ring of ductile metal such as copper is given a preliminary cold working, as by rolling, drawing, hammering &c. before machining and the edges of the band are pressed into the groove of the projectile to give a further cold working operation to these portions. A ring cut from a tube of annealed metal is cold worked to reduce its thickness and increase its width, thus increasing the strength and elasticity of the metal, and is then machined to the form shown in Fig. 3. The band is next attached to the projectile 4, Fig. 4, by deforming the edges into dovetailed recesses 8, 9 so that in firing the projectile, parts of the centre portion 5 of the band which has received one cold working operation only, will be forced by the rifling of the ordnance into the space 3 whilst the harder edges 6, 7 which have received two cold working operations will not come in contact with the rifling.