Abstract: A patch unit apparatus and method for expeditiously closing openings in metal walls by explosive welding. The patch unit comprises a metal plate having on one side an explosive charge located near the plate perimeter, and having on the opposite side a continuous double angled recess surface. After cleaning the wall surface, the patch unit is placed centrally over an opening to be closed and initially secured to the wall by an adhesive material provided on the plate side opposite from the explosive. If necessary, a mechanical type seal can also be used for improved sealing of the patch unit to the wall. The explosive charge is then detonated to explosively force the patch plate unit against the wall at high velocity, so as to weld the plate onto the metal wall to permanently close the opening, and thereby provide substantially the original strength to the metal wall.

Abstract: A fishing lure having a body movably mounting fin and tail simulations and having means responding to intermittent pulls on a fishing line for activating said fin and tail simulations.