The hydraulic rotary-percussive hammer drill includes a body; a shank; a striking piston configured to hit the shank; a stop piston configured to position the shank in a predetermined balanced position, the body and the stop piston delimiting a first control chamber permanently connected to a high-pressure fluid feed-in conduit and configured to urge the stop piston forwards, and a second control chamber configured to urge the stop piston forwards. The hydraulic rotary-percussive hammer drill comprises a fluidic communication channel opening into the second control chamber, configured to supply the second control chamber with high-pressure fluid and provided with a calibrated orifice.

The hydraulic rotary-percussive hammer drill includes a fluid injection portion including a fluid feed-in inlet and an annular inner groove fluidly connected to the fluid feed-in inlet; a shank including a fluid injection conduit fluidly connected to the annular inner groove; front and rear main sealing gaskets disposed on either side of the annular inner groove and configured to cooperate with a first shank portion of the shank; a rear backup sealing gasket located at the rear of the rear main sealing gasket and configured to cooperate with a second shank portion of the shank; a leakage passage defined between the shank and the fluid injection portion; pressure drop generation means configured to generate pressure drops in the leakage passage when a leakage flow flows in the leakage passage.

The present invention provides a drill assembly that includes a drill for drilling rock, a support for supporting the drill, and a valve for releasably securing the support and drill together. The valve is adapted to receive a fluid from a pump means and controllably provide the drill and the support with the fluid for operation of the drill and the support.

A pressure reversing valve for a fluid-actuated percussive drilling tool has a front thrust surface in communication with a rear chamber and a rear thrust surface in communication with a pressurized volume isolated from the flow coming from the source of pressurized fluid. The pressurized volume is in communication with a front chamber and allows the valve to take advantage of the imbalanced profile of the pressures inside the front and rear chambers that naturally occurs for enabling an asymmetric feeding process of the rear chamber that is also less sensitive to the bottom hole pressure.

A pressure reversing valve for a fluid-actuated percussive drilling tool has a front thrust surface in communication with a rear chamber and a rear thrust surface in communication with a pressurized volume isolated from the flow coming from the source of pressurized fluid. The pressurized volume is in communication with a front chamber and allows the valve to take advantage of the imbalanced profile of the pressures inside the front and rear chambers that naturally occurs for enabling an asymmetric feeding process of the rear chamber that is also less sensitive to the bottom hole pressure.

The invention relates to a device and a method for generating percussive pulses or vibrations for a construction machine, with a housing, a piston which is reversibly reciprocable in a working space in the housing between a first reversal point and a second reversal point, a pressure fluid supply, through which pressure fluid can in each case be led into and out of the working space in the region of the first reversal point and the second reversal point, wherein the piston can be set into the reversible movement in order to generate the percussive pulses or vibrations, at least one controllable valve, through which the pressure fluid can be led into and/or out of the working space, and a control unit which is connected to the at least one controllable valve, wherein by the control unit the movement of the piston in the working space can be controlled and changed. According to the invention provision is made in that the control unit is designed to move the piston at a frequency that corresponds to a resonance frequency of an overall arrangement comprising the piston and the pressure fluid.

A horizontal drilling machine with an impact device, including a support frame, an armored cable, a cable-straightening mechanism, a cable-feeding mechanism, a power head, a drill pipe, a rotating chuck, a damper, a fishing device with the impact device, a core tube and a thrust cylinder. One end of the thrust cylinder is hinged with the support frame, and the other end of the thrust cylinder is connected to the power head. The power head is arranged on a slid rail of the support frame. An active drill pipe of the power head is connected to the drill pipe. An end of the armored cable is connected to a control system, and the other end is connected to the fishing device in the drill pipe. A fishing head of the fishing device is connected to a spearhead of the core tube.

A horizontal drilling machine with an impact device, including a support frame, an armored cable, a cable-straightening mechanism, a cable-feeding mechanism, a power head, a drill pipe, a rotating chuck, a damper, a fishing device with the impact device, a core tube and a thrust cylinder. One end of the thrust cylinder is hinged with the support frame, and the other end of the thrust cylinder is connected to the power head. The power head is arranged on a slid rail of the support frame. An active drill pipe of the power head is connected to the drill pipe. An end of the armored cable is connected to a control system, and the other end is connected to the fishing device in the drill pipe. A fishing head of the fishing device is connected to a spearhead of the core tube.

A pressurized fluid flow system for a down the hole drill hammer has main and auxiliary chambers that exert work on the piston. The auxiliary chambers are formed around respective waists on the piston and externally delimited by respective cylinders which are arranged longitudinally in series. A set of supply chambers filled with the pressurized fluid are defined by annular recesses in the external surface of the piston for supplying said fluid to the chambers. Supply channels and discharge channels are formed in between the outer casing and the cylinders for respectively supply pressurized fluid through exit ports in the cylinders to the supply chambers and emptying the chambers through discharge ports in the cylinders. The supply and discharge of the chambers is controlled in a cooperative way by the piston and the cylinders. A normal circulation drill hammers is provided having this system.

A pressurized fluid flow system for a down the hole drill hammer has main and auxiliary chambers that exert work on the piston. The auxiliary chambers are formed around respective waists on the piston and externally delimited by respective cylinders which are arranged longitudinally in series. A set of supply chambers filled with the pressurized fluid are defined by annular recesses in the external surface of the piston for supplying said fluid to the chambers. Supply channels and discharge channels are formed in between the outer casing and the cylinders for respectively supply pressurized fluid through exit ports in the cylinders to the supply chambers and emptying the chambers through discharge ports in the cylinders. The supply and discharge of the chambers is controlled in a cooperative way by the piston and the cylinders. A normal circulation drill hammers is provided having this system.