Title:
【発明の名称】衝撃ドリルビット装置
Document Type and Number:
Japanese Patent JPH0735717
Kind Code:
B2
Abstract:
A percussion drilling apparatus for drilling bore holes into subterranean formation in which a plurality of drill rods are arranged in concentric rows in a drill bit housing, each rod having an impact tooth at its lower ends and the rods arranged either to converge inwardly adjacent to the center of the housing or to diverge outwardly at progressively increased angles in each row toward the outermost row. The impact teeth are fired sequentially by concentric combustion chambers arranged above the drill rods and where the pattern and rate of firing can be controlled by cam operated intake and exhaust valves associated with the combustion chambers. The drill bit housing is arranged at the lower end of the drill string with an umbilical cord which carries all necessary cables and lines between the surface controls and the drill bit housing for the purpose of controlling combustion in each chamber and of carrying away the cuttings as the drilling operation proceeds.
Inventors:
Gerald El Fletcher
Gregory Tea Fletcher
Gregory Tea Fletcher
Application Number:
JP27696489A
Publication Date:
April 19, 1995
Filing Date:
October 24, 1989
Export Citation:
Assignee:
Gerald El Fletcher
Gregory Tea Fletcher
Gregory Tea Fletcher
International Classes:
E21B1/00; E21B4/06; E21B4/14; E21B4/16; E21B7/00; E21B10/36; E21B21/16; (IPC1-7): E21B4/16
Domestic Patent References:
| JP62110380U |
Other References:
【文献】米国特許2400853(US,A)
Attorney, Agent or Firm:
Kyozo Yuasa (4 outside)
Next Patent: 縦坑の構築方法及びその装置