An example bushing of a hydraulic hammer tool includes an outer region and an inner region. The inner region has a relatively greater hardness than the outer region. The inner region may also be compressively stressed, while the outer region may have tensile stress. The stress and/or hardness profile of the bushing may enhance its resistance to wear and galling defects when a hammer of the hydraulic hammer tool is held in alignment by the bushing. The outer region of the bushing may be relatively soft, resulting in the bushing having a relatively high level of toughness. The bushing may be formed using medium to high carbon steel by rough forming the bushing, hardening the bushing, tempering the bushing, and induction softening the outer region of the bushing.

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 hydraulic percussion device comprising a piston mounted for reciprocal motion within a cylinder to impact a percussion bit and a control valve to control reciprocation of the piston. A valve pilot line is arranged to switch the control valve based on the position of the piston within the cylinder, wherein the valve pilot line is alternately connected, by the reciprocal movement of the piston, to high and low pressure lines (P, T) via an undercut in the piston. The undercut is located at a portion of the piston having a diameter less than the maximum sealing diameter of the piston.

A percussion drilling device for drilling in earth includes at least one housing section for a main piston, and a ring insert arranged in the housing section in front of the main piston so that the ring insert transmits at least part of the energy of the main piston onto the housing. The ring insert is attached to the housing by a shrink-fit connection.

A percussion drilling device for drilling in earth includes at least one housing section for a main piston, and a ring insert arranged in the housing section in front of the main piston so that the ring insert transmits at least part of the energy of the main piston onto the housing. The ring insert is attached to the housing by a shrink-fit connection.

A method of regulating the disassembly of a component from a powered tool assembly that uses a pressurized fluid and a locking member that is in operative association or communication with the fluid is provided. The method comprises biasing the locking member into a locked configuration using the pressurized fluid, preventing movement of the component in a first predetermined direction.

This hydraulic drilling apparatus including a casing comprising a front part, a shank including a fluid injection conduit and intended to be coupled to at least one drill rod equipped with a tool, the shank, a striking piston slidably mounted inside the casing along a striking axis (A) and configured to strike the shank, an extraction piston disposed around the shank and comprising an extraction portion configured to cooperate with the shank, and a cartridge removably mounted on the front part and disposed around the shank, the cartridge including an injection part configured to fluidly connect the fluid injection conduit to a fluid delivery conduit. The cartridge delimits a receiving housing in which the extraction piston is slidably mounted.

The invention concerns a hydraulic striking tool for application in rock and/or concrete cutting equipment containing a machine housing (100;200) with a cylinder (115;215) with a moveably mounted piston (145;245) which during operation performs a repetitive forward and backward movement relative to the machine housing (100;200) and directly or indirectly strike a rock and/or concrete cutting tool (155;255), and where the piston (145;245) includes a driving part (165;265) which separates a first (120;220) and a second (105;221) driving chamber formed between the piston (145;245) and the machine housing (100;200) and where these driving chambers are arranged to include a pressurized working fluid during operation. The total volume V of the first and second driving chambers is inversely proportional dimensioned to the square of a for the striking tool recommended maximal pressure p, as well as proportional, by a proportionality constant k within the interval 5.3-21.0, to the product of the pistons energy E during the strike against the tool and compression module β of the working fluid.

The invention concerns a hydraulic striking tool for application in rock and/or concrete cutting equipment containing a machine housing (100;200) with a cylinder (115;215) with a moveably mounted piston (145;245) which during operation performs a repetitive forward and backward movement relative to the machine housing (100;200) and directly or indirectly strike a rock and/or concrete cutting tool (155;255), and where the piston (145;245) includes a driving part (165;265) which separates a first (120;220) and a second (105;221) driving chamber formed between the piston (145;245) and the machine housing (100;200) and where these driving chambers are arranged to include a pressurized working fluid during operation. The total volume V of the first and second driving chambers is inversely proportional dimensioned to the square of a for the striking tool recommended maximal pressure p, as well as proportional, by a proportionality constant k within the interval 5.3-21.0, to the product of the pistons energy E during the strike against the tool and compression module β of the working fluid.

A remote demolition robot (10) comprising a controller (17), drive means (14), an arm member (11) movably arranged on a tower (10a) rotatably arranged on a body (11b) of the remote demolition robot (10) and a remote control (22) for providing commands, that are interpreted by the controller (17) causing the controller (17) to control the operation of the remote demolition robot (10), wherein the remote control (22) comprises a first joystick (24a) and a second joystick (24b), wherein the remote control (22) is characterized in that each joystick (24) is provided with a thumb control switch (26).