SLIT METAL STEMMING Russian patent published in 2007 - IPC F42D1/08 

FIELD: drilling and blasting operations in hard rocks, applicable in various braches using blasting operation in hard rock masses.

SUBSTANCE: the slit metal stemming is made in the form of a hollow-cylinder out in the axis with a tapered expansion in the bottom part, consisting of at least three parts of the same size, which at the top are provided with pins inserted in the guide bushes for motion in the horizontal plane, the guide bushes are fastened on a bearing ring coupled to the mantle ring on the bench surface by a distance tube. From the bottom of hollow spacing cone is inserted in the cylinder, it is coupled to a tubular link, having a thread, for a nut on the upper end and freely passing through the distance tube, a conductor of initiating pulse is passed through the tubular link.

EFFECT: enhanced efficiency of blast rock breaking due to the locking of the detonation products in the loading cavity up to the moment of complete destruction of the environmental rock by the slit metal stemming.

2 cl, 2 dwg