Method and apparatus for breaking hard compact material such as rock

摘要

A method of breaking hard compact material such as rock adjacent a hole drilled thereinto and an apparatus for performing the method are described. Two forces contribute to efficiently breaking the rock: a force for firmly gripping a region of material adjacent the hole and an axial outwardly directed force. When breaking the material the force for firmly gripping the material is unidirectional with but separate from the axial outwardly directed force. To generate these forces wedge means and sleeve means of the apparatus are inserted into the hole and an axial outwardly directed thrust is exerted on the sleeve means by means of cooperating sliding wedge surfaces of the wedge means and sleeve means which converge towards the apparatus power means. This power means as well as the thrust transmitting means for transferring the reaction force are situated outside the hole.