This percussion apparatus includes a body; a tool including a mounting portion slidably mounted in the body; and a striking piston mounted so as to be alternately displaced within the body and configured to strike the mounting portion. The mounting portion of the tool includes an annular retaining rib including a first bearing surface configured to cooperate with a first stop surface provided on the body so as to limit the displacement stroke of the tool towards the striking piston, and a second bearing surface opposite to the first bearing surface and configured to cooperate with a second stop surface provided on the body so as to limit the displacement stroke of the tool opposite to the striking piston and to retain the mounting portion of the tool in the body.

This percussion apparatus includes a body; a tool including a mounting portion slidably mounted in the body; and a striking piston mounted so as to be alternately displaced within the body and configured to strike the mounting portion. The mounting portion of the tool includes an annular retaining rib including a first bearing surface configured to cooperate with a first stop surface provided on the body so as to limit the displacement stroke of the tool towards the striking piston, and a second bearing surface opposite to the first bearing surface and configured to cooperate with a second stop surface provided on the body so as to limit the displacement stroke of the tool opposite to the striking piston and to retain the mounting portion of the tool in the body.

A tool bushing of a breaking hammer, a tool bushing arrangement, a breaking hammer and a method of mounting a tool bushing of a breaking hammer are disclosed. The tool bushing is a sleeve-like piece having a multi-shouldered outer surface with three or more successive cylindrical portions. The cylindrical portions have different diameters that match with corresponding surfaces of a bushing housing when the tool bushing is mounted. Diameters of the bushing and the bushing housing are dimensioned so that friction forces are generated when the bushing is assembled.

A tool bushing of a breaking hammer, a tool bushing arrangement, a breaking hammer and a method of mounting a tool bushing of a breaking hammer are disclosed. The tool bushing is a sleeve-like piece having a multi-shouldered outer surface with three or more successive cylindrical portions. The cylindrical portions have different diameters that match with corresponding surfaces of a bushing housing when the tool bushing is mounted. Diameters of the bushing and the bushing housing are dimensioned so that friction forces are generated when the bushing is assembled.

A rotary hammer adapted to impart axial impacts to a tool bit. The rotary hammer includes a housing, a motor supported by the housing, a spindle coupled to the motor for receiving torque from the motor, causing the spindle to rotate, a reciprocation mechanism operable to create a variable pressure air spring within the spindle, an anvil received within the spindle for reciprocation in response to the pressure of the air spring, the anvil imparting axial impacts to the tool bit, a bit retention assembly for securing the tool bit to the spindle, and an electromagnetic clutch mechanism switchable between a first state, in which the reciprocation mechanism is enabled, such that the anvil imparts axial impacts to the tool bit, and a second state, in which the reciprocation mechanism is disabled, such that the anvil ceases to impart axial impacts to the tool bit.

A rotary hammer adapted to impart axial impacts to a tool bit. The rotary hammer includes a housing, a motor supported by the housing, a spindle coupled to the motor for receiving torque from the motor, causing the spindle to rotate, a reciprocation mechanism operable to create a variable pressure air spring within the spindle, an anvil received within the spindle for reciprocation in response to the pressure of the air spring, the anvil imparting axial impacts to the tool bit, a bit retention assembly for securing the tool bit to the spindle, and an electromagnetic clutch mechanism switchable between a first state, in which the reciprocation mechanism is enabled, such that the anvil imparts axial impacts to the tool bit, and a second state, in which the reciprocation mechanism is disabled, such that the anvil ceases to impart axial impacts to the tool bit.

An inner-flanged bushing for a hydraulic breaker is a tubular shape having an inner flange and is made of a steel containing at least 0.55% and less than 0.70% by mass of carbon, at least 0.15% and less than 0.35% by mass of silicon, at least 0.4% and less than 0.9% by mass of manganese, at least 0.4% and less than 1.3% by mass of chromium, and at least 0.10% and less than 0.55% by mass of molybdenum, with the balance being iron and unavoidable impurities. The bushing includes a base region having a hardness of at least 30 HRC and less than 45 HRC, and a quench hardened layer formed on an inner periphery side of the base region to include an inner peripheral surface of a region including the inner flange, the quench hardened layer having a hardness of at least 55 HRC and less than 63 HRC.

An inner-flanged bushing for a hydraulic breaker is a tubular shape having an inner flange and is made of a steel containing at least 0.55% and less than 0.70% by mass of carbon, at least 0.15% and less than 0.35% by mass of silicon, at least 0.4% and less than 0.9% by mass of manganese, at least 0.4% and less than 1.3% by mass of chromium, and at least 0.10% and less than 0.55% by mass of molybdenum, with the balance being iron and unavoidable impurities. The bushing includes a base region having a hardness of at least 30 HRC and less than 45 HRC, and a quench hardened layer formed on an inner periphery side of the base region to include an inner peripheral surface of a region including the inner flange, the quench hardened layer having a hardness of at least 55 HRC and less than 63 HRC.

A method of retaining a hammer tool in the front head of a powercell assembly of a hammer assembly includes biasing a hammer tool retaining pin such that a portion of the tool retaining pin extends into a tool receiving bore of the front head of the powercell assembly, holding a hammer tool in the tool receiving bore of the front head of the powercell assembly via the tool retaining pin, and releasing the hammer tool remotely from the hammer assembly.

An improved hammer drill adapter, that is to be inserted into the variable-diameter, chuck end of a hammer drill for driving forward any one of a plurality of different types of sheet metal cleats to join the opposing ends of two sheet metal, duct sections, includes: (a) an elongated shaft having a drive end and a working end and a centerline between said ends, (b) the drive end configured to be releasably held in the hammer drill's chuck, (c) the working end having an elongated flat, front face that has top and bottom surfaces, two ends and with the front face oriented so that a perpendicular to the front face is parallel to the shaft's centerline, (d) the front face has an elongated cavity and a front face channel that are oriented approximately perpendicular to each other, and (e) wherein this cavity is configured to accommodate within it the end of a flat drive cleat, and the cavity and front face channel together are configured to accommodate within them the end of a standing drive cleat.