Patent · US Expired

Primer centering device for large diameter blastholes

US4961381A · kind A · utility

18Cited by
8References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 12, 1989
Grant dateOct 9, 1990
Priority date
Expiry dateMay 12, 2009

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF42B3/185
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

An improved method for reducing misfires in large diameter unlined blastholes by fitting on the primer used in the blasthole a centering device comprised of a semi-conducting plastic material.

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