Percussion borer for forming bores in stone material

US6640914B2 · kind B2 · utility

Assignee

• Hilti Aktiengesellschaft · LI

Inventors

• Erich Wisser · Bregenz, AT
• Marcel John · Mels, CH
• Bernhard Sander · Munich, DE
• Hanspeter Schad · Grabs, CH
• Cord-Henrik Surberg · Feldkirch, AT
• Charles C. Coffin · Vernon, US
• Joachim Vedder · Hergensweiler, DE
• Reinhard Lins · Sevelen, CH

Key dates

• Filing date: Apr 11, 2002
• Grant date: Nov 4, 2003
• Expiry date: Apr 11, 2022

Classification

• Technology area (CPC E): Fixed Constructions
• CPC primary: E21D21/0053
• WIPO field: Civil engineering
• WIPO sector: Other fields

Abstract

A percussion bores for forming borer in a stone material and including a chisel stem (2) having a prismatic cross-section and provided with a chiseling head (3) and at least one radial opening (4), a twist drill (6) extending through the cylindrical through-bore (3) of the chisel stem and projecting beyond the chiseling head (7), a drilling head (10) with cutting elements (9) provided at the projecting end of the twist drill and a shank (12) provided at another end of the twist drill, and a stop (13) provided between the shank (12) and the chisel stem (2), with a drill stem being offset radially inwardly with respect to an outer diameter of the shank in the region of the stop.