The rotary-percussive hydraulic perforator a body; a shank; a striking piston configured to strike the shank and provided with a braking surface; a braking chamber configured to hydraulically brake the striking piston; a stop piston configured to apply a pushing force on the shank and provided with a bearing surface configured to abut against a stop surface provided on the body, so as to limit the stroke of displacement of the stop piston towards the shank. The rotary-percussive hydraulic perforator is configured such that the bearing surface and the stop surface are axially spaced apart by a predetermined spacing distance simultaneously when (i) the shank bears on the stop piston and is in contact with the striking piston, and (ii) the braking surface is located at an inlet edge of the braking chamber.

The rotary-percussive hydraulic perforator a body; a shank; a striking piston configured to strike the shank and provided with a braking surface; a braking chamber configured to hydraulically brake the striking piston; a stop piston configured to apply a pushing force on the shank and provided with a bearing surface configured to abut against a stop surface provided on the body, so as to limit the stroke of displacement of the stop piston towards the shank. The rotary-percussive hydraulic perforator is configured such that the bearing surface and the stop surface are axially spaced apart by a predetermined spacing distance simultaneously when (i) the shank bears on the stop piston and is in contact with the striking piston, and (ii) the braking surface is located at an inlet edge of the braking chamber.

A hydraulic breaking hammer and method of supporting a percussion piston is provided. The breaking hammer includes a percussion device provided with a reciprocating piston. The piston is supported on a frame at its end portions by a first piston bearing element and a second piston bearing element. The second piston bearing element includes a collar sealing element facing towards a working collar of the piston. The piston bearing elements are easily mountable and dismountable separate components.

An impact tool has an anti-topping mechanism (“ATM”) adapted to reduce the rotational frictional force between the contact surfaces of the hammer and anvil to prevent topping. If topping still occurs, the ATM quickly breaks the topped condition. The ATM may reduce the rotational frictional torque between the hammer and anvil of an impact mechanism or provide increased the rotational friction acting on the anvil from adjoining elements of the tool thus tending to hold the anvil (by heightened rotational friction) while the hammer can be broken free. ATM mechanisms include hammer and jaw surfaces angled at interface points; stepping either the hammer or anvil jaw surfaces so that only the innermost portions interact; rounding or crowning either or both of the anvil and hammer jaw surfaces so minimal portions of the jaws are ever topped; and software-controlled detection and breaking of a topped condition. In torque-controlled impact tools, these mechanisms decrease the risk of accuracy or repeatability issues.

An impact tool has an anti-topping mechanism (“ATM”) adapted to reduce the rotational frictional force between the contact surfaces of the hammer and anvil to prevent topping. If topping still occurs, the ATM quickly breaks the topped condition. The ATM may reduce the rotational frictional torque between the hammer and anvil of an impact mechanism or provide increased the rotational friction acting on the anvil from adjoining elements of the tool thus tending to hold the anvil (by heightened rotational friction) while the hammer can be broken free. ATM mechanisms include hammer and jaw surfaces angled at interface points; stepping either the hammer or anvil jaw surfaces so that only the innermost portions interact; rounding or crowning either or both of the anvil and hammer jaw surfaces so minimal portions of the jaws are ever topped; and software-controlled detection and breaking of a topped condition. In torque-controlled impact tools, these mechanisms decrease the risk of accuracy or repeatability issues.

A power tool having a rotary hammer mechanism is configured to produce hammering motion for driving a tool accessory along a driving axis and rotating motion for rotating the tool accessory around the driving axis. The power tool has a tool holder that is configured to removably hold the tool accessory. The tool holder has a rotation transmitting part configured to transmit rotating power to the tool accessory. A layer formed of carbide of a group 5 element of a periodic table is formed on the rotation transmitting part.

A power tool having a rotary hammer mechanism is configured to produce hammering motion for driving a tool accessory along a driving axis and rotating motion for rotating the tool accessory around the driving axis. The power tool has a tool holder that is configured to removably hold the tool accessory. The tool holder has a rotation transmitting part configured to transmit rotating power to the tool accessory. A layer formed of carbide of a group 5 element of a periodic table is formed on the rotation transmitting part.

An impact power tool includes a housing, a motor, a controller, an output member configured to be rotated when the motor is energized, and an impact mechanism configured to rotationally drive the output member. The impact mechanism is configured to selectively apply rotational impacts to the output member when a torque on the output member exceeds a torque threshold. The controller is configured to control the motor during a first phase of operation with open loop control and a baseline conduction band and advance angle setting when a sensed tool operation parameter is one of above or below a threshold value. The controller is configured to control the motor during a second phase of operation with closed speed loop control and an increased conduction band and advance angle setting when the sensed tool operation parameter is the other of above or below the threshold value.

An impact power tool includes a housing, a motor, a controller, an output member configured to be rotated when the motor is energized, and an impact mechanism configured to rotationally drive the output member. The impact mechanism is configured to selectively apply rotational impacts to the output member when a torque on the output member exceeds a torque threshold. The controller is configured to control the motor during a first phase of operation with open loop control and a baseline conduction band and advance angle setting when a sensed tool operation parameter is one of above or below a threshold value. The controller is configured to control the motor during a second phase of operation with closed speed loop control and an increased conduction band and advance angle setting when the sensed tool operation parameter is the other of above or below the threshold value.

An impact power tool includes a housing, a motor, a controller, an impact mechanism configured to be driven by the motor, and an output spindle configured to receive rotational impacts from the impact mechanism to rotate the output spindle. The controller is configured to detect a first impact of the rotational impacts or to detect when the motor speed drops below a speed threshold value. The controller is configured to control the motor to have a first non-zero target rotational speed using closed loop control for a predetermined time period after the first impact is detected or when the motor speed dropping below the speed threshold value is detected. The controller is configured to control the motor to have a second non-zero target rotational speed using the closed loop control after the predetermined time period. The first non-zero target rotational speed is less than the second non-zero target rotational speed.