A percussion mechanism device, in particular for an impact wrench, includes a drivable drive shaft that has at least one guide groove, an output shaft, and a percussion unit that includes an anvil coupled with the output shaft in a rotationally fixed manner, a hammer, and at least one ball. The hammer is supported via the at least one ball along the at least one guide groove on the drive shaft and includes an at least regionally concavely curved ball guidance area that has an axial clearance from the at least one ball at a radially innermost point that is greater than a radial clearance between the at least one ball and a radially innermost point of a concave ball guidance area of the at least one guide groove.

A drill bit for chiseling stone includes an impact face at an insertion end of the drill bit, a hollow shank, where a delivery passage is defined within the hollow shank, and a drill head, where the drill head has, at a front end of the drill head, a cutting edge, an intake opening, and an intake passage. The intake passage connects the intake opening to the delivery passage. A cross section of the intake passage increases from the intake opening to the delivery passage.

A hammer drill having an impact mechanism and a rotary drive, wherein the hammer drill is designed to rotate a tool at a speed n about a longitudinal axis of the tool and to drive it with an output impact power PS along the longitudinal axis with a striking movement is disclosed. At a working point, at least one condition is met: 1. The ratio of the output impact power PS to the speed n is at least 3.5 W/rpm; 2. Depending on the output impact power PS, the speed n is at most (PSAN−300)2/2000+150) rpm; 3. In the event of an infinitesimal change in the output impact power PS, the speed n changes by at most 0.1 rpm/W.

A hand-held power tool includes a tool fitting, an impact mechanism, and a rotary drive. The hand-held power tool is configured to rotate a tool held in the tool fitting with a rotational speed about a longitudinal axis of the tool and to drive the tool with an impact movement along the longitudinal axis at an impact frequency f. A ratio of the rotational speed to the impact frequency f at least at a working point of the hand-held power tool is at most 5.0 rpm/Hz or at least at the working point of the hand-held power tool the rotational speed is at most (0.2*(f/Hz-22){circumflex over ( )}2+80) rpm for impact frequencies f in a range from 20 to 60 Hz.

Systems and methods for management of material stresses present at transitions between facets of an anvil and the anvil shaft are described. In one aspect, an apparatus includes an impact tool anvil extending along an axis of extension and having a faceted drive end and a shaft body which is connected to the faceted drive end through a transition region that couples respective faces of the faceted drive end to the shaft body, the transition region including a sweeping radius surface having a first axial end and a second axial end, the first axial end connected to a respective face of the faceted drive end, the first axial end having a tangency with the respective face of the faceted drive end; and an angular transition having a slope that radially rises from the second axial end of the sweeping radius surface to the shaft body.

A reciprocating tool includes a motor, a driving mechanism, a body housing, a movable part, and a vibration control mechanism. The driving mechanism includes a reciprocating member configured to reciprocate in a first direction. The movable part is connected to the body housing via a first elastic member and a second elastic member to be relatively movable in the first direction. The vibration control mechanism includes at least one weight configured to move in a direction opposite to the reciprocating member. The center of gravity of the at least one weight is offset from the driving axis in a second direction. In the second direction, the first elastic member is closer to the center of gravity than the second elastic member. A load of the first elastic member when the movable part is placed in a closer position is smaller than a load of the second elastic member.

A reciprocating tool includes a motor, a driving mechanism, a body housing, a movable part, and a vibration control mechanism. The driving mechanism includes a reciprocating member configured to reciprocate in a first direction. The movable part is connected to the body housing via a first elastic member and a second elastic member to be relatively movable in the first direction. The vibration control mechanism includes at least one weight configured to move in a direction opposite to the reciprocating member. The center of gravity of the at least one weight is offset from the driving axis in a second direction. In the second direction, the first elastic member is closer to the center of gravity than the second elastic member. A load of the first elastic member when the movable part is placed in a closer position is smaller than a load of the second elastic member.

A drill bit for chiselling rock includes an impact face at an insertion end of the drill bit, a hollow shank, where a delivery passage is defined within the hollow shank, and a drill head, where the drill head has a cutting edge, an intake opening, and an intake passage and where the intake passage connects the intake opening to the delivery passage. A first portion of the intake passage which adjoins the intake opening has a first inclination with respect to a drill bit axis, a second portion of the intake passage which adjoins the hollow shank has a second inclination with respect to the drill bit axis, and the second inclination is greater than the first inclination.

A percussion mechanism device, in particular for an impact wrench, includes a drivable drive shaft that has at least one guide groove, an output shaft, and a percussion unit that includes an anvil coupled with the output shaft in a rotationally fixed manner, a hammer, and at least one ball. The hammer is supported via the at least one ball along the at least one guide groove on the drive shaft and includes an at least regionally concavely curved ball guidance area that has an axial clearance from the at least one ball at a radially innermost point that is greater than a radial clearance between the at least one ball and a radially innermost point of a concave ball guidance area of the at least one guide groove.

A drill bit for chiselling rock includes an impact face at an insertion end of the drill bit, a hollow shank, where a delivery passage is defined within the hollow shank, and a drill head, where the drill head has a cutting edge, an intake opening, and an intake passage and where the intake passage connects the intake opening to the delivery passage. A first portion of the intake passage which adjoins the intake opening has a first inclination with respect to a drill bit axis, a second portion of the intake passage which adjoins the hollow shank has a second inclination with respect to the drill bit axis, and the second inclination is greater than the first inclination.