614,521. Whaling harpoons. MARCUS, M. M., and GABRIELSEN, N. July 18, 1946, No. 21546. Convention date, Sept. 11, 1945. [Class 9 (i)] A harpoon having a shaft and a barb-carrying head is provided with intersecting passages extending at right-angles to each other through the head, the barb elements being pivoted in the passages and formed to coact with means in the head to automatically lock the barbs against displacement from the passages and limit the outward swing of the barbs. Furthermore, the barb elements are provided with adjustable means for holding them in engagement with projections on the harpoon shaft during flight. The harpoon has a cylindrical shank 10 slotted at 12 to receive a slip-ring carrying a line, the forward end of the shank being a coupling-eye 11 having on opposite sides lugs 13 with a flat seat 14. A member 15 on which are pivoted barbed elements 16 ends in a coupling- eye 19 interlocking with the eye 11. The forward end of the member 15 is provided with a spear-headed cap 31 containing an explosive charge initiated by a detonating-fuze in a longitudinal bore 34 in the member 15. Four barbs 16, uniformly spaced around the member 15 and pivoted on pins 21 mounted between pairs of projecting ears 20, have at their pivoted ends inwardly-projecting terminal elements 22 which enter intersecting passages 23, 24 and, when the barbs are swung outwards, engage the side walls 26 of a square depression 25 in the member 15 to limit the outward movement of the barbs and hold them in position should the pivot pins 21 be sheared through. Each barb has at its outer extremity a hook element, which, in the case of the barbs engaging with the lugs 13, has an enlarged end 28 with a tapped hole 29 therein to receive a set-screw 30, which can be adjusted to ensure locking engagement between the barbs 16 and the coupling eye 11 of the shank. A tie-cord wrapped round the barbs holds the two barbs not in locking engagement with the shaft, until the head of the harpoon explodes.