A portable power tool is disclosed. The tool has a tool holder in which a tool can be moveably inserted on a working axis in a striking direction. A percussion mechanism has a striker coupled via a pneumatic chamber to an exciter moved periodically along the working axis and an intermediate striker arranged in the striking direction downstream from striker. The intermediate striker is guided in a slide bearing with a tolerance coaxially to the working axis. The intermediate striker has a ring-shaped bead. A hollow-cylindrical backstop is arranged in the striking direction upstream from the bead. The backstop is moveably guided on a sliding surface with radial play along working axis. The radial play is at least three times as large as a tolerance of the guide of the intermediate striker in the slide bearing.

A power tool includes a housing; a handle having two ends, each being moveably mounted to the housing associated mountings; and a biasing mechanism connected between the housing and the handle; wherein at least one of the mountings comprises: a first part mounted on the housing and a second part mounted on the one end of the handle, one part comprising a passageway, the other comprising a rod, having a longitudinal axis, which is located in and capable of being axially slid within the passageway, enabling the end of the handle to move towards or away from the housing; at least part of the wall of the passageway in a lengthwise direction of the passageway comprises a curved convex support surface capable of engaging the side of the rod to enable the rod to pivot within the passageway about an axis which is perpendicular to the axis of the rod.

A clearance control system for a hydraulic hammer is disclosed. The hydraulic hammer includes a housing member, a power cell disposed within the housing member, a wear member disposed between the housing member and the power cell, and a clearance control system for controlling the predefined clearance between the wear member and the power cell. The clearance control system includes a mounting boss and a fastening member disposed on the mounting boss. A first end of the fastening member is configured to receive an input from an operator and the second end is configured to contact with the first surface of the wear member. The fastening member is configured to move along a central axis defined by a threaded hole of the mounting boss to move the wear member towards the power cell, to control the predefined clearance between the wear member and the power cell.

A clearance control system for a hydraulic hammer is disclosed. The hydraulic hammer includes a housing member, a power cell disposed within the housing member, a wear member disposed between the housing member and the power cell, and a clearance control system for controlling the predefined clearance between the wear member and the power cell. The clearance control system includes a mounting boss and a fastening member disposed on the mounting boss. A first end of the fastening member is configured to receive an input from an operator and the second end is configured to contact with the first surface of the wear member. The fastening member is configured to move along a central axis defined by a threaded hole of the mounting boss to move the wear member towards the power cell, to control the predefined clearance between the wear member and the power cell.

An impact rotary tool includes a hammer, an anvil, an output shaft, a housing, and a bearing (first bearing). The bearing (first bearing) is held by the housing. The anvil includes a first contact portion. The output shaft includes a second contact portion. The second contact portion receives, from the first contact portion, force that causes the output shaft to rotate. The bearing (first bearing) is in contact with at least one of the first contact portion or the second contact portion and supports at least one of the output shaft or the anvil rotatably.

An impact rotary tool includes a hammer, an anvil, an output shaft, a housing, and a bearing (first bearing). The bearing (first bearing) is held by the housing. The anvil includes a first contact portion. The output shaft includes a second contact portion. The second contact portion receives, from the first contact portion, force that causes the output shaft to rotate. The bearing (first bearing) is in contact with at least one of the first contact portion or the second contact portion and supports at least one of the output shaft or the anvil rotatably.

An automotive assembly line tool system and method utilizing a heat-shrinkable bumper disposed around a portion of an assembly line tool for absorbing kinetic energy between the portion of the tool and a work-piece on an assembly line. The bumper may be a chemically cross-linked polyolefin heat-shrinkable material having a shore D hardness of 42 or less after being heat-shrunk. The bumper may be a tubular bumper that has a continuous outer surface around its circumference and a heavy wall that is highly split-resistant. The bumper may have a life term of at least one year in an automotive assembly line environment. By protecting the tools and equipment, chips and scratches on a work-piece on the assembly line may be reduced.

An automotive assembly line tool system and method utilizing a heat-shrinkable bumper disposed around a portion of an assembly line tool for absorbing kinetic energy between the portion of the tool and a work-piece on an assembly line. The bumper may be a chemically cross-linked polyolefin heat-shrinkable material having a shore D hardness of 42 or less after being heat-shrunk. The bumper may be a tubular bumper that has a continuous outer surface around its circumference and a heavy wall that is highly split-resistant. The bumper may have a life term of at least one year in an automotive assembly line environment. By protecting the tools and equipment, chips and scratches on a work-piece on the assembly line may be reduced.

A power tool is less likely to generate noise. A power tool includes a housing, a field fixed to the housing and including a field coil, an armature rotatable relative to the field and including a commutator, two brushes that come in contact with the commutator, and a brush holder unit holding the two brushes. The brush holder unit includes two contact rails electrically connectable to the field coil, two first terminals that each come in contact with either of the two contact rails, two second terminals each electrically connectable to a corresponding brush of the two brushes, and a choke coil located between at least one of the two first terminals and at least one of the two second terminals.

A power tool is less likely to generate noise. A power tool includes a housing, a field fixed to the housing and including a field coil, an armature rotatable relative to the field and including a commutator, two brushes that come in contact with the commutator, and a brush holder unit holding the two brushes. The brush holder unit includes two contact rails electrically connectable to the field coil, two first terminals that each come in contact with either of the two contact rails, two second terminals each electrically connectable to a corresponding brush of the two brushes, and a choke coil located between at least one of the two first terminals and at least one of the two second terminals.