GB264973A - Improvements in or relating to submarine mines - Google Patents

Abstract

264,973. Vickers, Ltd., and Pratt, H. B. Nov. 27, 1925. Mines, marine. - Relates to automatically moored mines of the kind in which the mine and the anchor first sink together as a unit and after reaching a predetermined depth or the sea bottom separate from each other, and the mine then rises until stopped at the desired depth by means of a hydrostat, which stops the paying out of an auxiliary line from a drum carried by the mine with the hydrostat, the pull of the auxiliary line causing the stopping of the main mooring cable drum in the anchor and, if desired, also the detachment of the hydrostatic devices from the mine, for example, as described in Specifications 262,917 and 264,290. According to the invention, the diaphragm C of the hydrostat. is controlled for depth by means of compressed air instead of by a spring as heretofore; but a spring C<1> may be used in addition for the minimum depth of say 3 metres. The diaphragm C is preferably arranged inside the drum A of the auxiliary line A', and compressed air is supplied by a pump to the closed chamber A<2> behind this diaphragm through an axial duct in the spindle C<2> of the diaphragm a non-return valve c' and a screw cap c being provided at the end of the spindle. A pressure gauge B<1> connected to the pressure chamber indicates the corresponding depth. The spindle C<2> is normally locked by a transverse bolt D secured by a shear pin D' and connected by a short line to the anchor of the mine. When the mine separates from the anchor, the pin D<1> is sheared and the bolt D pulled out. At the appointed depth, the diaphragm C is moved outwards, and a groove c<2> in its spindle C<2> liberates ball f<1> releasing a disc F, which is moved to the right by a spring F<2> and pushes spring bolts E, carried by the drum, into engagement with stops B<2> on the fixed casing B, thereby stopping the drum.