Illustrative embodiments impact tools with torque-limited swinging weight impact mechanisms are disclosed. In at least one illustrative embodiment, a swinging weight impact mechanism may comprise a hammer configured to rotate about a first axis and pivot about a second axis different from the first axis, the hammer having a void formed therein, and an asymmetric anvil disposed partially within the void, the asymmetric anvil being configured to rotate about a third axis when impacted by the hammer. The asymmetric anvil may comprise a cylindrical body and a lug extending outward from the cylindrical body. The lug may include a first impact face extending along a first plane that intersects the third axis and a second impact face extending along a second plane that does not intersect the third axis, where the second plane intersects the first plane along a line that passes through the cylindrical body of the asymmetric anvil.

An impact tool has a smaller diameter in its portion around a front end of an anvil. The impact tool includes a motor, a hammer rotatable by the motor, an anvil having a tool hole to receive a tip tool and being strikable by the hammer in a rotation direction and having a ball hole, a ball movable, through the ball hole, between an entered position at which the ball is at least partially inside the tool hole and a retracted position at which the ball is outside the tool hole, and at least one button operable to move the ball radially.

A power tool has a handle, a tool body, a rotator, a first working unit, and a second working unit. The handle has a handle body, a mounting ring rotatably mounted around the handle body, and a switch mounted on the mounting ring and inserted into the handle body. The tool body is mounted on the handle. The rotator is mounted in the tool body, and has a first driving end and a second driving end. The first working unit is mounted in the tool body, and is mounted around and engaged with the rotator. The second working unit is mounted in the tool body, and is mounted around and engaged with the rotator.

A secondary hammer support structure in a rotary impact tool is structured such that a plurality of steel balls are disposed between a secondary hammer and a retaining member. The plurality of steel balls are arranged between the first retaining groove of the secondary hammer and the second retaining groove of the retaining member. The retaining member is formed as a member separate from the spindle and has a retaining surface for retaining steel balls and a mounting surface mounted to the spindle so as not be rotatable. The mounting surface of the retaining member is mounted to a front member of a carrier.

An electric power tool includes: a driving shaft that is rotated by a motor; an output shaft on which a front-end tool is attachable; and a torque transmission mechanism that transmits a torque produced by the rotation of the driving shaft to the output shaft. The torque transmission mechanism includes a magnet coupling including a driving magnet member coupled to a side of the driving shaft and a driven magnet member coupled to a side of the output shaft, and the driving magnet member and the driven magnet member are provided such that respective magnetic surfaces face each other, S-poles and N-poles being alternately arranged on each of the magnetic surfaces.

The durability of a reduction mechanism is improved. An impact wrench includes a brushless motor, a sun gear rotatable by the brushless motor, a planetary gear meshing with the sun gear, an internal gear meshing with the planetary gear and having a first recess on an outer circumference, a gear case holding the internal gear and having a second recess on an inner circumference, a spindle holding the planetary gear, and a pin disposed in the first recess and in the second recess.

Illustrative embodiments of impact tools with impact mechanisms rigidly coupled to electric motors are disclosed. In at least one illustrative embodiment, an impact tool may comprise an impact mechanism, an electric motor, and a control circuit. The impact mechanism may comprise a hammer and an anvil, the hammer being configured to rotate about a first axis and to periodically impact the anvil to drive rotation of the anvil about the first axis. The electric motor may comprise a rotor that is rigidly coupled to the impact mechanism, the electric motor being configured to drive rotation of the hammer about the first axis. The control circuit may be configured to supply a current to the electric motor and to prevent the current from exceeding a threshold in response to the hammer impacting the anvil.

An impact tool includes a motor, a first hammer, an anvil, and a second hammer. The first hammer is configured to be rotated by driving of the motor. The anvil is configured to be hammered in a rotation direction by the first hammer. The second hammer is configured to be switchable between a state being linked and a state not being linked to the first hammer. The impact tool ensures selections of a first hammering mode in which only the first hammer hammers the anvil and a second hammering mode in which the first hammer and the second hammer hammer the anvil.

In order to suppress a galling phenomenon between an impact member and a rotating member even when a gouging force acts on an impact tool, an inclined portion is provided between a wall portion which is provided between a pair of hammer cams and in a circumferential direction of a through-hole and a bottom portion which is provided in each center portion of the hammer cams and in the circumferential direction of the through-hole, the inclined portion which has a smaller size than a size of the wall portion in the shaft direction of the through-hole and a larger size than a size of the bottom portion in the shaft direction of the through-hole and against which the spindle is pushed when the first pawl and the second pawl are engaged with each other.

An impact rotary tool includes: a driver; a spindle rotated by the driver; a primary hammer rotatable about an axis of rotation of the spindle and movable in a direction of the axis of rotation; a secondary hammer accommodating the primary hammer and rotatable integrally with the primary hammer; and an anvil applied with rotary stroke force by the primary hammer. An engaging pin is engaged with the primary hammer and the secondary hammer, integrally rotates the primary hammer and the secondary hammer, and allows the primary hammer to move in the direction of the axis of rotation. An elastic member is disposed in an annular groove formed in a circumferential direction on the inner peripheral surface of the secondary hammer and limits movement of the engaging pin.