Apparatus for loosening and/or breaking coal deposits, rocks, granular or lumpy material, or scrap
US4626031A · kind A · utility
2Cited by
3References
1Claims
0Family size
Assignees
Inventors
Key dates
| Filing date | Dec 21, 1984 |
| Grant date | Dec 2, 1986 |
| Priority date | — |
| Expiry date | Dec 21, 2004 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21C41/18
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An apparatus for breaking coal or other mineral matter from a bed thereof which comprises a string filling a bore hole which can rise steeply in this bed. The string consists of alternating breaking units and connecting pipes each braking unit having a differential piston displaced solely by the action of air pressure so that breaking slots are unblocked to discharge compressed air built up in the string. The pistons are provided with check valves to permit filling of the string.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.