A hydraulic hammer is disclosed having a piston and an accumulator membrane disposed external and co-axial to the piston. Additionally, a sleeve is disposed between the piston and accumulator membrane, wherein the sleeve has a plurality of radial passages formed therein that fluidly connect the accumulator membrane with the piston.

A hammer drill includes a housing inside which a motor, a tubular tool holder, a driving mechanism, a rotation conversion member, and an inner housing are disposed. The driving mechanism is configured to perform at least one of rotation actuation of the tool holder and hammering actuation of a bit. The inner housing supports the driving mechanism, supports the tool holder via a first bearing, and supports an output shaft via a second bearing. The inner housing is divided into a front housing holding the first bearing and a rear housing that is formed in a separate body from the front housing and holds the second bearing. The inner housing is formed by connecting the front housing to the rear housing in an axis line direction of the tool holder. A seal member sealing outside space of the inner housing inside the housing is disposed in the front housing.

A power tool contains one or more moving parts coated with a lubricant to reduce friction. The lubricant is intended to be sealed within a housing of the power tool. In order to better prevent leakage of the lubricant to the exterior of the housing, the housing and/or a component supported by the housing includes a part exhibiting oil repellency. The oil repellency is preferably imparted at least at a junction of the housing and the component supported by the housing. The oil repellency may be imparted by applying a fluorine-based coating or a nanocoating to the junction. In addition or in the alternative, the oil repellency may be imparted by forming a portion or all of the housing from a resin material containing an oil-repelling component and/or by attaching an oil-repellant component at or proximal to the junction.

A hammer drill includes a housing inside which a motor, a tubular tool holder, a driving mechanism, a rotation conversion member, and an inner housing are disposed. The driving mechanism is configured to perform at least one of rotation actuation of the tool holder and hammering actuation of a bit. The inner housing supports the driving mechanism, supports the tool holder via a first bearing, and supports an output shaft via a second bearing. The inner housing is divided into a front housing holding the first bearing and a rear housing that is formed in a separate body from the front housing and holds the second bearing. The inner housing is formed by connecting the front housing to the rear housing in an axis line direction of the tool holder. A seal member sealing outside space of the inner housing inside the housing is disposed in the front housing.

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.

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 reciprocating tool includes a motor, a motion converting mechanism, a body housing, an inner housing, a support body, and a counterweight. The motion converting mechanism is operably coupled to a motor shaft and is configured to convert rotation into a linear reciprocating motion along a driving axis. The inner housing is within the body housing and houses at least a portion of the motion converting mechanism. The support body is originally separate from the inner housing and is attached to the inner housing in the body housing. The counterweight is operably coupled to the motion converting mechanism and is configured to be driven by the motion converting mechanism. The counterweight is supported by the support body to be pivotable around a pivot axis that extends in a direction orthogonal to the driving axis. At least a portion of the counterweight is housed in the inner housing.

A hammer including a housing and a piston arranged for reciprocating movement within the housing is disclosed. The hammer further includes a head assembled on the housing and defining a chamber for holding a pressurized gas and a wall configured to abut the housing and defining a gas discharge passage extending between the chamber and the housing. A plug is positioned in the gas discharge passage and configured to move or deform under pressure of the pressurized gas in the chamber.

A machine tool includes a tool holder and a pneumatic striking mechanism that includes, on a working axis, an exciter piston, a beater, and a pneumatic chamber disposed between the exciter piston and the beater. The exciter piston is drivable by the motor and includes a pot-shaped base body, a seal ring, and a tube-shaped cladding body. The pot-shaped base body has a lateral wall enclosing the working axis and a collar which protrudes in a radial direction. The tube-shaped cladding body is disposed on the pot-shaped base body surrounding the lateral wall. A groove is defined between the collar and the tube-shaped cladding body and the seal ring is disposed in the groove.

A percussion tool including a parking assembly movable relative to a spindle. The parking assembly includes a seat coupled to the spindle, a first shuttle portion movable relative to an outer surface of the spindle, a biasing member positioned between the seat and the first shuttle portion, a second shuttle portion movable relative to the outer surface of the spindle, a bushing positioned within the spindle and configured to receive a portion of an anvil, and a fastener that couples the second shuttle portion to the bushing. The first shuttle portion and the second shuttle portion are movable together between a working position, in which a plurality of radial air vents in the spindle is closed, and an idle position, in which the plurality of radial air vents is open. The biasing member is configured to bias the first shuttle portion and the second shuttle portion into the idle position.