GB572509A - Improvements connected with marine mines - Google Patents

Abstract

572,509. Marine mines. JEFFERIS. M. R., and MACRAE, R. S. March 1, 1940, No. 3903. [Class 9 (ii)] A marine mine equipped with a parachute for sowing from aircraft has the firing mechanism armed automatically by a sliding assembly which is constantly urged to the arming position where elements of the assembly can be relatively displaced to fire the mine by the action of an inertia member when the mine is impacted. In the form shown, the mine comprises a casing 1 with a buoyancy compartment 3, a charge chamber 4, and a central tubular casing 12 containing the arming and firing mechanism. A detachable casing 60 contains a parachute or drogue 63 and a cork float 62, the float being connected to the mine through a cable looped through an eyelet 73<1> on a sealing disc 19 and the parachute being connected to the float by a cable including a link 65 which is disrupted after a time determined by a soluble plug to release the parachute. On launching the mine from aircraft, the cover 60 remains behind and the pull exerted when the parachute opens serves to remove the sealing disc 19. The firing mechanism comprises an assembly including a firing pin 39 having a disc 51 retained by arms 31 movable radially on pivots 32 and embracing a weight 30. The arms 31 are retained at safe by the wall of the tube 12, the firing assembly being urged upwardly by a spring 47, but being prevented from rising by a rod 27 bearing against the sealing disc 19 and having a piston member resting against a soluble plug 22. After removal of the sealing disc, water enters the chamber 20 and the firing assembly gradually rises as the plug 22 is dissolved until the upper ends of the arms 31 enter an enlargement in the tube 12. The firing mechanism is then armed and on the mine being impacted, the weight 30 can then operate to swing the arms about their pivots 32 to release the firing pin 39 on to the detonator 54 situated in the initiating charge 55.