Abstract: The tool mounted in a body of an apparatus is retained by a cotter engaging inside a notch of the tool, the cotter being engaged in a borehole of the body. The area of the body containing this borehole for engagement of the cotter is equipped with a covering ferrule. This ferrule is provided for occupying a first position in which it at least partially occludes the borehole and a second position in which the borehole is cleared for enabling the cotter to be inserted or removed.

Abstract: A hydraulic rotary percussive hammer drill includes a body containing a reciprocating percussion piston sliding under the effect of a main hydraulic supply circuit, this main circuit also being intended to cause the sliding of a roughly annular abutment piston housed in a cavity of the body, and having, on the one hand, a front face in contact with a shank and intended to place this shank a predetermined distance away from the percussion piston and, on the other hand, a rear face facing a rear wall of the cavity, characterized in that an external hydraulic supply circuit is able, when the main circuit is shut down, to introduce fluid under pressure between the rear face of the abutment piston and the rear wall of the cavity so as to maintain a space between these items.

Abstract: The invention concerns an apparatus comprising a body (1) containing a cylinder wherein is mounted sliding an impact piston (1) of a tool, the motion of the piston being controlled by a distributor (15) which, arranged coaxial to the impact piston, is mounted inside a distribution box (3). The distribution box (3) comprises a part axially overlapping the piston (1) and arranged concentric thereto, and the distribution box (3) defines with the piston a control chamber (13) which, successively put under the high (9) and the low (12) pressure of the fluid, communicates through a passage (16) arranged in the distribution box (3) with a chamber controlling (14) the movement of the distributor (15), to generate alternately low pressure and high pressure.

Abstract: A device for supplying hydraulic power to a rotary apparatus for percussive drilling (2) whereof the tool (3) is driven in one direction or another and subjected to the action of an impact device (6) acting independently of the rotation, of a hydraulic device (9) with forward movement enabling the tool to generate a pressure force on the ground, and optionally of a suction device (14) for the drilling dusts, driven by a hydraulic motor, the various hydraulic actuating elements being driven from a hydraulic liquid source under pressure through a hydraulic flow divider (16), a set of distributors (17, 18, 19, 20) and an assembly of branch pipes outside the apparatus, such as hose pipes. The device includes a branch pipe external to the apparatus (24) for communicating the return branch pipe (22) of the hydraulic device (4) driving the tool in rotation and the supply line (23) of the impact device (6), to add to the supply rate of the impact device the return flow rate of the rotation driving device.

Abstract: A percussive hydraulic apparatus includes a body inside which is mounted a cylinder in which an impact piston is guided. Fluid distribution providing the motion of the piston is produced by a distributor housed in a distribution box mounted in the body. The cylinder and the distribution box are entirely contained in the enclosure defined by the body, with the cylinder being mechanically supported by one of its ends of the body. The distribution box is mounted coaxial to the cylinder and is mechanically supported thereon. Surfaces perpendicular to the axis of the apparatus, subjected to pressure, are arranged and dimensioned such that the resultant hydraulic forces applied on the cylinder and distribution box during all the phases of the operating cycle thereof are directed in the same direction towards a support located in the body of the apparatus.

Abstract: A muffler for a pneumatic hammer of the type in which a cylinder receives a piston or ram which is pneumatically driven into contact with an anvil, e.g. the rear end of a tool, and in which the discharge of the air is muffled to limit the noise generated by the apparatus. The air to be discharged into the atmosphere is vented into an annular space between an outer wall of a sleeve or head surrounding the cylinder and connected by an elastic suspension thereto.

Abstract: A mining drill comprising a rail along which a mining drill head is slidably rectilinear, this rail being carried by a hydraulic motor pivotally connected to a rotary head at the end of an arm swingable about a pivot axis which is generally horizontal and is formed by a column or post. A first hydraulic motor is provided to rotate the post about a generally upright axis and hydraulic cylinders can be provided to swing the post about a pivot close to its pedestal. The device is designed to support the rail so that substantially parallel holes can be drilled in a subterranean structure in practically any direction, e.g. with any inclination to the axis of the main gallery, but especially parallel thereto.

Abstract: A percussion tools such as a pneumatic hammer, drill, concrete braker and the like in which a ram is pneumatically reciprocated in a cylinder to drive a tool, has a head provided with the handles gripped by the user and forming a pneumatic cushion with the cylinder. According to the invention, this head carrying the handles is mounted with slight clearance slidably on the cylinder and the pneumatic cushion is formed between the upper end of the cylinder and the interior of the head. A sleeve attached to the head and surrounding the cylinder communicates with the cylinder through the usual reciprocation-producing valve and a portion of the air pressure is bled through the clearance into the cushion. A vent passage of the cylinder communicates with the cushion chamber and can register with a passage in the sleeve opening into the atmosphere.