Patent · US Expired

Drill steel

US4749051A · kind A · utility

9Cited by
8References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 26, 1985
Grant dateJun 7, 1988
Priority date
Expiry dateSep 26, 2005

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T408/907
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A drill steel for percussion drilling has four longitudinally extending grooves for removal of cuttings. The grooves are shaped such that, in comparison with a hexagonal drill steel, there is obtained an enlarged space for cuttings and a less consumption of material with maintenance of the same resistance to bending.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.