GB250314A - Improvements in or relating to depth setting gear for submarine mines - Google Patents

Abstract

250,314. Vickers, Ltd., and Pratt, H. B. Jan. 7, 1925. Mines, marine. - Relates to automatically moored submarine mines of the kind provided with means for adjusting the length of the plummet line determining the depth of the mine. According to the invention, the unwinding of a predetermined length of plummet line is controlled by varying the starting position of contiguous members adapted to be angularly displaced relativelv to one another by the unwinding of the plummet line. Tn the form shown, when the mine is launched, the plummet A, Fig. 5. falls off, and its line B breaks a twine lashing a and, after taking up the initial slack, pays itself out from and rotates a drum C. A planet pinion E rotatable on a pin E<1>, Fig. 1, on the drum is carried round two toothed wheels F, G, one F fixed and the other G rotatable and formed with a few teeth more or less than the fixed wheel. Each revolution of the drum, therefore gives a small angular displacement to the wheel G, until a spring plunger J carried thereby snaps through a hole f in the wheel F and into a hole c in the drum, thereby locking the drum to the spindle H. An arm K on this spindle connected to a lever L by a block M thereupon shears a pin N and releases a slip hook P, freeing the mine from the sinker. And on a further slight rotation of the drum the lever K acting through a block S and a link R on a bell-crank lever u pulls a stop T from a ratchet T' on the mooring rope drum, allowing the mooring operation to take place. When the plummet touches bottom, the slack in the plummet line allows a spring V to restore the pawl T into engagement with the ratchet T to stop the mooring rope drum. The effective length of plummet line paid out of the drum C is determined by the initial angularposition of the spring plunger J relatively to the hole f. This is adjusted by pulling the pinion E out of mesh with the wheels F, G by means of a screw W, then turning the wheel G to the desired angle relatively to the wheel F, as indicated by a pointer on the wheel G against a. scale on the wheel F, and finally re-engaging the pinion E with the wheels F, G. This mechanism is protected by a detachable cover X.