An electropneumatic impact mechanism for an electric hand-held power tool, in particular a hammer drill and/or chipping hammer, wherein the impact mechanism has a transmission housing, a guide tube arranged at least partially in the transmission housing, an exciter piston that is movable in the guide tube, a connecting rod coupled to the exciter piston, and an eccentric wheel which is designed as an externally toothed gearwheel and is coupled to the connecting rod on one side and is mounted so as to be rotatable with respect to the transmission housing about an axis of rotation on the other side, an axial gap, preferably for optionally receiving at least part of a lubrication space separating element, is provided between an eccentric wheel surface facing the connecting rod and a connecting rod surface facing the eccentric wheel.

An objective is to provide a technique to securely protect the striking tool even when the striking tool inadvertently falls down. A striking tool including a rotating shaft relatively rotatably connect a main body with a handle, a first elastic member reducing transmitting of vibration from the main body to the handle in a case that the handle relatively rotates to the main body, wherein the handle includes a battery mounting portion to which battery to drive the motor is attachable and the handle is arranged to relatively move to the main body across the rotating shaft, and an adjuster such that the relative movement amount of the handle to the main body in a predetermined direction is adjusted to be larger than the relative movement amount in a direction other than the predetermined direction.

A pneumatic tool structure contains an air intake head, a slidable sleeve, a drive unit, a piston, an operation element, a resilient element, a first isolation ring, and a second isolation ring. The air intake head includes a press lever, an air channel, and a connection portion. The connection portion has a first coupling orifice. The slidable sleeve includes a shoulder. The drive unit includes a body, a recessed portion having a defining fringe, a screw bolt, and a chamber. An air discharge conduit is defined between the slidable sleeve and the body. The first segment has a second coupling orifice. The resilient element includes a through hole. The first isolation ring includes a first rim, a second rim, multiple first discharging grooves, and multiple first contact portions. The second isolation ring includes a third rim, a fourth rim, multiple second discharging grooves, and multiple second contact portions.

A power tool for chiseling and drilling includes a housing, a motor disposed inside the housing, and a pneumatic percussion mechanism. An operation mode selector switch is disposed on the housing and has a first operation mode setting and a second operation mode setting where the first operation mode setting activates the pneumatic percussion mechanism and the second operation mode setting deactivates the pneumatic percussion mechanism. A valve has an inlet-port formed inside the guiding tube and an outlet-port formed outside the guiding tube where the valve is connected to the operation mode selector switch. The valve is closed in the first operation mode setting which disables an air exchange between the inlet-port and the outlet-port and the valve is open in the second operation mode setting which enables the air exchange between the inlet-port and the outlet-port.

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 rotary hammer includes a motor, a spindle coupled to the motor for receiving torque from the motor, a piston at least partially received within the spindle for reciprocation therein, and an anvil received within the spindle for reciprocation in response to reciprocation of the piston. The anvil imparts axial impacts to a tool bit in response to reciprocation of the piston. The rotary hammer also includes a bit retention assembly for securing the tool bit to the spindle.

A pneumatic hammer extender arm assembly is provided comprising an elongated extender arm body defining a hammer engaging portion formed at a first end of the body, and a hammerhead engaging portion formed at a second end of the body. A hammerhead is detachably engageable to the hammerhead engaging portion to allow for quick change of the hammerhead without the need for any tools. The hammerhead may alternately be implemented to engage and apply an impact force to a fastener that may be axially offset from the extender arm body.

A hand-held machine tool for a striking tool has a motor, an impact mechanism, a spool valve, and a pneumatic chamber. The impact mechanism has an exciter piston moved by the motor, and a hammer coupled to the exciter piston via a pneumatic chamber between the exciter piston and the hammer, and a striker in front of the hammer in the striking direction. In a working position counter to the striking direction, the striker bears on a stop, in a starting position the striker is offset in the striking direction relative to the working position, and in a rest position the striker is offset in the striking direction relative to the starting position. In the starting position, the hammer bearing on the striker closes the spool valve and, in the rest position, the hammer bearing on the striker opens the spool valve.

A striking tool restricting movement of an intermediate member toward a striker reliably prevents no-load strokes. A hammer drill includes a cylindrical tool holder holding a tip tool, a motor, a piston that reciprocate with rotation from the motor, a striker that reciprocate in cooperation with the piston, an intermediate member reciprocably accommodated in the tool holder between the striker and the tip tool and in contact with a rear end of the tip tool at a normal strike to indirectly transmit a strike from the striker to the tip tool, and at least two ring members that move in a front-rear direction accommodated in the tool holder at a front of the intermediate member between the tool holder and the intermediate member. At least one ring member is made of metal.

A hammer drill is provided with a hammer mechanism that includes a cylinder having a central axis, a ram having a radial recess slidably mounted within the cylinder, a piston slidably mounted within the cylinder, and a ram catcher. The ram catcher includes a first ring and a second ring surrounding the central axis and forming a groove therebetween, the second ring being located between the first ring and the end of the cylinder. An O-ring that is resiliently-deformable is mounted within the groove and includes an inner side projecting inwardly towards the central axis. When the ram is in a working position, the O-ring is located forward of the ram. When the ram is in a forward position, the O-ring is located in-line with the radial recess of the ram.