PURPOSE: To make an ignition block capable of sliding between the loading position of a detonator and the position of firing and at the position of firing to enable incorporating the detonator simply and safely in the launching tube by manipulation of a trigger and by fixing the ignition block by the use of an adapter which holds the detonator inside.

CONSTITUTION: An ignition block 1 has flanges 2 on two sides, is fitted into corresponding cut hollows 3 radially extending in the wall of a tube, and made capable of being slid on an adapter 4 which has been screwed tightly into the wall of the tube by means of a screw thread 7. A detonator 5 is fitted in the adapter 4. Manipulation of one or both of two triggers acts on two hammers 9 of a plate 11 which has been moved by a spring 10 to one side and hammering pins 12 fixed to the underside of the plate 11 strike the head of the adapter 4 in a manner of igniting the detonator 5. A spring 13 holds the hammering pins 12 a little above the head of the adapter 4 while the ignition block 1 slides, therefore, the hammering pins 12 do not come in contact with the adapter 4.