Hilti Aktiengesellschaft

Charles Coffin

Hanspeter Schad

Erich Wisser

Bernhard Sander

Reinhard Lins

Joachim Vedder

Marcel John

Cord-Henrik Surberg

A percussion bores for forming borer in a stone material and including a chisel stem ( ) having a prismatic cross-section and provided with a chiseling head ( ) and at least one radial opening ( ), a twist drill ( ) extending through the cylindrical through-bore ( ) of the chisel stem and projecting beyond the chiseling head ( ), a drilling head ( ) with cutting elements ( ) provided at the projecting end of the twist drill and a shank ( ) provided at another end of the twist drill, and a stop ( ) provided between the shank ( ) and the chisel stem ( ), with a drill stem being offset radially inwardly with respect to an outer diameter of the shank in the region of the stop.

Percussion borer for forming bores in stone material

Growing community of inventors

Chur, Switzerland

Charles Coffin