Abstract: A wireline operated overshot is disclosed. In the illustrated embodiment, the overshot includes a grapple which is located internally of a sleeve telescoped about it having a tapered internal shoulder. The grapple engages and disengages a fish. In the event the overshot becomes stuck on a fish, it can be released by downwardly jarring movement which shears a pin. The pin is located to permit a limited range of telescoping movement between the grapple and telescoped external sleeve. A spring is incorporated which forces the grapple downwardly against the tapered sleeve. The apparatus includes a latching mechanism which overcomes the spring to move the parts to a released position.

Abstract: This device assures the underwater recovery of heavy objects by marine mals. A trigger mechanism releases sections of spring biased tubing which converged about the object. After the tubing sections interconnect, the marine mammal pulls free and the object is retrieved by a hoisting line. If the object is partially buried in marine sediment, a pair of pressurized gas cartridges are ruptured to jet a pathway for the converging tubular sections. Because the tubing sections are inherently strong, the hoisting line optionally is connected directly to them or to a suitably arranged bridle. The lightweight concentrically arranged tubing sections are capable of lifting heavy loads and are designed to assure reliable trouble free operation.