Method and apparatus for controlled small-charge blasting by decoupled explosive
US6435096B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 10, 2000 |
| Grant date | Aug 20, 2002 |
| Priority date | — |
| Expiry date | Dec 6, 2020 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF42D3/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A cartridge containing an explosive charge is inserted at the bottom of a short hole drilled in the rock. The cartridge is held in place or stemmed by a massive stemming bar of high-strength material such as steel. The cartridge incorporates additional internal volume designed to control the application of pressure in the bottom hole volume by the detonating explosive. The primary method by which the high-pressure gases are contained in the hole bottom until relieved by the opening up of controlled fractures, is by the massive inertial stemming bar which blocks the flow of gas up the drill hole except for a small leak path between the stemming bar and the drill hole walls. The stemming bar is preferably connected to a boom mounted on a carrier. A preferred embodiment incorporates an indexing mechanism to allow both a drill and a small-charge blasting apparatus to be used on the same boom for drilling and subsequent charge insertion and firing operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.