Method of breaking a hard compact material, means for carrying out the method and application of the method
US3988037A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 1975 |
| Grant date | Oct 26, 1976 |
| Priority date | — |
| Expiry date | Apr 17, 1995 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21C37/12
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A hard compact material, such as rock, is broken by delivering a hydraulic fluid, such as water, into at least one hole which has been pre-drilled in the material to be broken, the hole functioning as an hydraulic fluid cylinder. A piston is driven into the hole to impact the fluid to generate a high pressure in the fluid and to cause tensile stress cracks in the material by the established pressure. Due to the concentration of the stress at the bottom of the hole, the cracks are initiated and spread generally radially outwardly substantially normal to the principal stress direction. A plurality of said holes may be drilled and the cracks linked together by appropriate choice of form, depth, orientation, spacing and number of the holes. Preferably, the piston is driven into the hole by means of a gun at speeds ranging up to several hundred meters per second.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.