A protection assembly for a work implement includes an outer shield member and an inner shield member. The outer shield member is spaced from a housing of the work implement in a longitudinal direction and defines a channel. The channel extends to an exterior of the protection assembly. The inner shield member defines an opening and is slideably disposed in the channel. The inner shield member is free to slide in a transverse direction that is substantially perpendicular to the longitudinal direction. Movement of the inner shield member in the longitudinal direction is restricted by the housing of the work implement and the outer shield member. Movement of the inner shield member in the transverse direction is restricted by a work tool that is locked within and projects out of the housing and through the opening in the inner shield.

The sealing device includes an inner sealing ring including an annular inner sealing portion provided with a sealing lip intended to cooperate in a sealed manner with the outer surface of a striking piston of a hydraulic percussion apparatus, and an outer sealing element mounted around the inner sealing portion and intended to bear in a sealed manner at the bottom of an annular housing arranged on a guide body of the hydraulic percussion apparatus. The inner sealing ring further includes an annular protective portion axially shifted relative to the inner sealing portion and internally delimited by at least one converging protective surface, annular and converging towards the sealing lip, and an annular groove opening into the inside the inner sealing ring, the annular groove being disposed between the sealing lip and the converging protective surface.

An impact tool which transmits an impact force to a tool bit supported by a casing includes: a cylinder which is attached to the casing and has an opening on one end side thereof to which the tool bit is inserted; an intermediate element which is provided in an inside of the cylinder so as to be able to move straight, has a projection projecting in a radial direction so as to regulate a range of the straight movement, and transmits the impact force to the tool bit; and passages and which communicate a space in an inside of the cylinder at a position nearer to the tool bit than the projection with the outside of the cylinder and penetrate through the cylinder in the radial direction.

A method of retaining and removing a valve locking body from a powered hammer assembly comprises inserting a locking member into a radially extending aperture of a cylinder, inserting a spring until the spring contacts the locking member; and inserting a keeper radially inwardly of the spring and the locking member and attaching the keeper to the cylinder.

The present invention discloses an electric chisel capable of being matched with a domestic electric drill to be used. The electric chisel comprises an electric drill, a casing, a push rod and chisel head mechanism and a groove cam mechanism. The top of the casing is provided with an oil hole, and a rubber plug is arranged on the oil hole to be used for preventing dust; the two ends of the groove cam mechanism are provided with a first bearing and a second bearing respectively, and a first groove and a second groove are formed below the first bearing and the second bearing respectively and positioned in the inner wall of the casing. The groove cam mechanism is provided with a groove, and the push rod and chisel head mechanism is connected with the groove cam mechanism and performs reciprocating motion up and down in the groove of the groove cam mechanism. During the use, the whole electric chisel is installed on the domestic electric drill, and when the groove cam mechanism is driven by the electric drill to rotate, the push rod and chisel head mechanism performs liner reciprocating motion. The electric chisel is simple in structure, small in size, portable and convenient to operate and can quickly chisel floors or wall tiles.

A hammer drill comprising: a body; a motor mounted within the body; a transmission housing mounted within the body, a transmission mechanism mounted within the transmission housing which is capable of rotatably driving and/or repetitively striking a cutting tool held by the hammer drill in response to rotation of an output shaft of the motor; wherein the transmission housing comprises a pair of housing portions adapted to engage each other to support the component parts of the transmission mechanism within the transmission housing; wherein the first housing portion is made from metal and the second housing portion is made from a plastic material, each of the components of the transmission mechanism being supported jointly be the first and second housing portions.

A mobile power tool comprising a drive unit is disclosed. The drive unit has an aqueous lubricant and/or the drive unit is set up for operation with the aqueous lubricant, wherein, before the start of a running-in phase of the drive unit, a bond roughness sigma of two interacting contact surfaces of the drive unit is greater than 0.01 m, preferably at least 0.1 m.

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 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 plug assembly configured for installation in a hammer assembly, the plug assembly comprising a cylindrical plug and an anti-rotation component. The cylindrical plug may include a plug head and a plug body. The plug head may include a first hole and a second hole opposite the first hole, each hole extending from the outer surface of the plug head. The anti-rotation component may include a first linear portion and a second linear portion. The first linear portion and second linear portion may both be configured to fixably engage with the hammer assembly.