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.

A rotary hammer is adapted to impart axial impacts to a tool bit. The rotary hammer comprises a housing, a motor supported by the housing, a gearcase, and a spindle housed in the gearcase and coupled to the motor for receiving torque from the motor, causing the spindle to rotate. The rotary hammer also comprises a reciprocating impact mechanism operable to create a variable pressure air spring within the spindle. The rotary hammer also comprises a vibration damping mechanism including a base on the gearcase, a counterweight circumscribing the base, and a first spring arranged between the base and the counterweight and defining a first biasing axis that is parallel to the reciprocation axis. The vibration damping mechanism also includes a second spring arranged between the base and the counterweight and arranged along the first biasing axis.

A rotary power tool comprises a drive mechanism including an electric motor and a transmission, a housing enclosing at least a portion of the drive mechanism, a spindle rotatable in response to receiving torque from the drive mechanism, a first ratchet coupled for co-rotation with the spindle, a second ratchet rotationally fixed to the housing, a sleeve bushing on an interior of the housing, and a bearing arranged between the spindle and the sleeve bushing and rotatably supporting the spindle. The bearing has an outer race. The spindle is movable relative to the housing in response to contact with a workpiece, causing the first and second ratchets to engage and the spindle to reciprocate while rotating. The outer race of the bearing moves along the sleeve bushing during reciprocation of the spindle when the first ratchet and second ratchet are engaged.

A hand-held power tool includes an electric motor, a tool unit, and at least one operating unit. A motor switching unit is configured to sense a contact-pressure characteristic between the tool unit and the operating unit, and configured to switch the electric motor at least partially in dependence on the contact-pressure characteristic.

An attachment configured for use with a powered hammer to drive a rod into the ground includes a body, an impact portion, and a driving portion in which the rod is receivable. The impact portion defines an impact axis and includes a bore configured to receive a driving shank coupled to the powered hammer. The impact portion is configured to receive repeated impacts from the powered hammer. The driving portion includes a side load driving portion defining a side load driving axis that is parallel to the impact axis. The driving portion further includes a top load driving portion defining a top load driving axis that is parallel to the side load driving axis.

An electric hammer comprising an electric motor, a spindle coupled to the electric motor and adapted to be driven by the electric motor, an impacting member adapted to be coupled to the spindle and driven by the spindle, and a direction changing device adapted to be coupled with the impacting member. The direction changing device changes the direction of movement of the impacting member such that the kinetic energy of the impacting member is provided to an energy storage device for accumulation after the change in the direction of movement. The energy storage device is adapted to return the accumulated energy to the impacting member such that the latter generates an impacting force to an output member.

A hand-held electric hammer includes a handle arrangement on a tool carrier shank in which a striking mechanism actuated by an electric motor is accommodated and at the lower end of which a tool holder is arranged, which is suitable for receiving a tool attachment in the form of a spade blade, a demolition chisel, or a PVC scraper. The handle arrangement is designed as a T-shaped T-handle seated on the tool carrier shank, so that on both sides of the tool carrier shank there are two handles for both a left and a right hand of a user, whereby in the lower half of the tool carrier shank an additional handle stub is attached protruding in parallel with the T-handle from the tool carrier shank, which allows the electric hammer to be gripped with one hand on the T-handle and with the other hand on the additional handle stub.

A hydraulic hammer includes a power cell. A work tool is partially received in, and movable with respect to, the power cell. A sleeve is positioned in the power cell that defines a centerline. A piston is concentrically positioned in the sleeve and movable in the sleeve between a first position in contact with the work tool and a second position out of contact with the work tool. A magnetic guide system includes at least one of a first magnetic guide component disposed in the piston and at least one of a second magnetic guide component disposed in the sleeve that interact to produce magnetic repellent forces therebetween to urge the radial position of the piston towards the center line.

A power tool comprises a housing having at least two housing parts and at least one recess, a portion of the recess provided by each housing part, and a bearing located in the recess. The power tool includes a seal comprising an elongate seal member located between the housing parts to seal at least a portion of the housing. The seal includes at least one polymeric extension part extending from the elongate seal member and in contact with an external part of the bearing without extending around the bearing. The polymeric extension part of the seal prevents the external part of the bearing from rotating with respect to the housing during use of the power tool.

An axial bearing for reducing wear is provided in an overload clutch for arrangement between a drive unit and a power take-off unit of a hand-held power tool in order to enable decoupling of the drive unit from the power take-off unit in the hand-held power tool when a limit torque is exceeded.