GB251751A - Improvements in or relating to depth charges, bombs, projectiles and other explosivebodies - Google Patents

Abstract

251,751. Vickers, Ltd., and Ogden, A. April 9, 1925. Projectile fuzes.-Relates to hydrostatic firing- devices for depth charges of the kind comprising a pistol unit and a primer unit driven against each other by hydrostatic pressure, the depth at which they come together to bring about explosion being determined by the amount of air trapped between them, for example, as described in Specification 248,416. According to the invention, means are provided to prevent the complete approach of the firing elements by momentum under shock, while permitting the approach under hydrostatic pressure. In the form shown in Fig. 1, the pistol unit C and the primer unit D are both movable in a tube B provided with an internal collar a, which stops either element from reaching the other when subjected to shock, but allows the elements to reach each other when they are both moved inwards by hydrostatic pressure, compressing the air contained in the space E between them. In Fig. 2, the pistol element F is fixed and forms the safety stop in the middle of the tube G. The primer I is movable in the tube on one side of the pistol, and a casing H containing accessory air chambers J, J<1> is movable on the other side of the pistol. The chambers J, J' may be cut off from the air space K between the casing H and the primer I, or one or both of these chambers may be put in communication with the chamber E, according to the setting of a valve M, which therefore enables the device to be set for three different depths. The fixed pistol F prevents either of the movable elements reaching the other by momentum under shock; but, under hydrostatic pressure, both elements H and I are moved inwards. The element H bears on a plunger f<1> and compresses the spring f<2> of the pistol. The element I embraces the detonator f' and bears on a shoulder f', further compressing the firing spring f<2> until balls N escape out into a recess f<5> and release the striker f<6>. The movable elements are provided with rubber sealing-rings L.