US Patent 7506877 Bit or tool extension and method of making same

An apparatus, method and system for extending working tool or bit from a source of rotary power, including a body with a shank, blind bore for the shank of the tool or bit, a tangential bore, a clamping member insertable through one end of the clamping bore, the clamping member having an internal threaded bore, a threaded fastener inserted through the other end of the clamping bore into the threaded bore of the clamping member, an opening into the blind bore into which a wedging section of the clamping member can be drawn tangentially by action of the threaded member.