Blade-equipped drilling tool, incorporating secondary cutting edges and passages designed for the removal of evacuated material
US5957227A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Nov 19, 1997 |
| Grant date | Sep 28, 1999 |
| Priority date | — |
| Expiry date | Nov 19, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/602
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A drilling tool has several blades 16 each defining an outside wall 20 and two side walls 22, 24. The blades are separated by recesses 18, primary bits 28 are located along the outside wall of the blades, and secondary or backup bits 40 are attached behind the primary bits in relation to the direction of travel (f) of the tool. Each of the blades defines at least one divergent tunnel or channel 30 having small entry opening 32 located in the outside wall of the blade, behind the primary bits, and a larger exit opening 34 located on the rear side of the blade. The secondary bits are mounted at the rear edge of the entry opening, and the channel serves to discharge material excavated by them.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.