An insert bushing arrangement of a breaking hammer, a breaking hammer and a method of supporting a breaking tool of a breaking hammer is provided. The insert bushing arrangement includes a bearing support inside which an insert bushing is mountable. Between the bearing support and the insert bushing is one or more intermediate material layers for preventing jamming of the components.

The invention relates to a striking hand-held machine tool having a tool holder for holding a striking tool on a working shaft, an electric motor, and a striking mechanism. In the striking direction, the striking mechanism has an exciter piston, a pneumatic chamber, a striker, an intermediate chamber and a rivet snap following one another. A closed channel connects a first channel opening in the pneumatic chamber and a second channel opening in the intermediate chamber. A non-return valve, which shuts off during an air flow from the first channel opening to the second channel opening and opens during an air flow from the second channel opening to the first channel opening, is arranged in the channel. Arranged on the second channel opening is a shut-off valve, which is forced into a position closing the second channel opening when the rivet snap is in the working position.

A hammer drill having a motor mounted within a body and an output spindle; a tool holder mounted on the body capable of holding a cutting tool; a hammer mechanism having a piston; a reciprocating drive for converting rotary movement of the motor into reciprocating movement of the piston; a ram reciprocatingly driven by the piston via an air spring to strike a cutting tool held in the tool holder, the hammer mechanism performing one hammer cycle each time the ram strikes a cutting tool during normal use; an air replenishment mechanism capable of refreshing the air spring during certain time periods during normal use; the air replenishment mechanism capable of being adjusted to refresh the air spring during time periods within the hammer cycle and/or the system allows different volumes of air into or out of the air spring during the refreshment time periods.

A hand-held power tool device is described which includes an output unit, a striker, and a rotary percussion receiver which is designed for establishing a transfer of rotary percussions between the striker and the output unit, at least during a rotary percussion operation. It is provided that the hand-held power tool device includes a rotary percussion switch-off device which is designed for interrupting the transfer of rotary percussions from the striker to the rotary percussion receiver, at least during a hammer percussion operation.

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 ground stake kit includes at least one elongated ground stake having a top end, a bottom end and a middle portion. The stake being constructed from a weather resistant material plastic or composite material and having a rough textured outer surface. A cap is secured to the top end of the ground stake and is constructed from a hardened material such as metal to receive repeated impacts from the striker of an air hammer. A sleeve aligns the stake with an air hammer. The sleeve includes a first end having a shape and size that is complementary to the neck of an air hammer, and a second end having an alignment collar for receiving the cap and first end of the ground stake.

A hand-held power tool, in particular a hammer drill or combination hammer, having a tool fitting for holding a striking and rotating tool on a working axis, an electric motor coupled to a transmission shaft, an impact mechanism, which has a striker that is moved periodically along the working axis, and having a rotary drive, which drives a guide tube carrying the tool fitting in rotation about the working axis, wherein the rotary drive is coupled to the transmission shaft via a rocker lever.

A hand-held power tool includes a tool receptacle with which a tubular tool holder configured to receive an application tool is associated, and a locking device configured to lock the application tool in the tubular tool holder. The locking device locks the application tool in a locking position via at least one locking element in the tubular tool holder. The locking device has a locking sleeve and a pressure ring spring loaded via an associated spring element. The spring-loaded pressure ring is configured to force the locking sleeve into the locking position and, in the locking position, forces the at least one locking element against the tool holder.

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.

This percussion apparatus includes a striking piston mounted so as to be displaced inside a piston cylinder and arranged to strike a tool; and a guide bearing comprising a guide surface configured to guide the striking piston during the displacements of the striking piston in the piston cylinder. The guide bearing includes a centering device configured to center the striking piston in the piston cylinder, the centering device comprising centering chambers formed in the guide surface and distributed around the striking piston, each centering chamber being fluidly connected to a high pressure fluid supply circuit; and at least one discharge groove formed in the guide surface of the guide bearing and located proximate to at least one of the centering chambers, the at least one discharge groove being fluidly connected to a low pressure circuit.