Hydraulically operated subsoil displacement apparatus

A hydraulically operated subsoil displacement apparatus comprising a shell which surrounds a hydraulic impact mechanism with a linearly slidable hammer, in which under the action of hydraulic oil supplied from a supply of oil under pressure by a first hydraulic hose and withdrawn pressurelessly by a second hydraulic hose to a tank, reciprocating movement of said hammer is created with blows against a forward or rear impact point inside the apparatus, and in which change of the impact point is effected by axial displacement of a tube which extends centrally and axially into the hammer,

• in which pressurized oil is supplied through the first hydraulic hose by a valve connected to the supply of oil under pressure and the second hydraulic hose connected to the tank, said valve being formed to reverse connections of the first and second hydraulic hoses,
• the apparatus having a hose union for each hose where each hose union is connected to an oil duct connected to discharge oil to one side of a piston secured to the tube, the piston having at least one oil duct connected to the interior of the tube,
• the piston being closed at an end opposite the tube and the apparatus having two fluid conduits for oil which are formed by a series of adjoining ducts and cavities in the apparatus and in the piston for the supply and withdrawal of oil, the two fluid conduits being completely separate in the apparatus.