“Twin-impact” double-blow drilling apparatus

Boring unit for pile foundations

Casing hammer power swing-out apparatus for drilling rig

Device for controlling the passage of a flushing medium in impac

Device for efficient energy transfer and damping of impact drill

Device for simulataneously casing a hole while drilling

Drilling device for the study and exploitation of the subsoil

Drilling device with an impact-rotation tool

Drilling rig

Engine-driven breaker

Hammer device

Hand-held smoker's device for sidestream smoke control

Impact device

Inner pipe support arrangement for double-walled drill pipe

Machine for horizontal percussion boring

Method and apparatus for driving pipe

Percussive tool with high pressure fluid jet

Removable filter fluid flow shutoff apparatus

Rock drilling apparatus

Rock drilling device with recoil damper