Tag Archives: cohesionless

Hole drilling technology for cohesionless prestressed concrete roof board

Application Number  00129321 Application Date  2000.11.17 Publication Number  1290798 Publication Date  2001.04.11 Priority Information     International Classification  E04G23/02   Applicant(s) Name  Hu Wei   Address     Inventor(s) Name  Hu Wei;Hong Xiang;Wang Fushuang   Patent Agency Code  37100 Patent Agent  wu wei AbstractThe hole drilling includes the process of digging concrete floor board in… Read More »