Apparatus for rotary mining

Bit for drilling an undercut hole

Bore undercutting tool

Boring tool for radial enlargement of a cylindrical foundation b

Downhole tool with extendable members

Drill for water wells

Drilling tool

Drilling tool with extendable elements

Expandable gage bit for drilling and method of drilling

Expansible tool for reaming frustoconical undercuts in cylindric

Hole digging apparatus and method

Method of setting a pile without noise or vibration and apparatu

Pantograph underreamer and method for forming a well bore...

Reaming and stabilization tool and method for its use in a...

Reaming and stabilization tool and method for its use in a...

Reaming and stabilization tool and method for its use in a...

Rotary expansion tool for reaming frustoconical undercuts in the

Toggle actuated underreamer

Undercutting device for anchor holes

Undercutting drill