A hammer drill includes a housing, a tool holder, a hammering member, a gear, and a conversion member. The gear is switched to a first state where a rotation of the intermediate shaft is transmitted and a second state where the rotation of the intermediate shaft is not transmitted, and a mode switching member is configured to perform a switching operation of the state of the gear from an outside of the housing. The switching of the state of the gear by the mode switching member provides at least two operation modes of a hammer drill mode where the gear integrally rotates with the intermediate shaft to generate the rotation and a reciprocation of the hammering member on the tool holder and a hammer mode where the gear is separated from the rotation of the intermediate shaft to generate only the reciprocation of the hammering member to be selectable.

A rotary hammer includes a housing, a first motor supported by the housing and defining a first motor axis, a second motor supported by the housing and defining a second motor axis that is coaxial with the first motor axis, and a spindle coupled to the first motor for receiving torque from the first motor, causing the spindle to rotate. The rotary hammer further includes a reciprocation mechanism operable to create a variable pressure air spring within the spindle. The reciprocation mechanism includes a piston configured to reciprocate within the spindle in response to receiving torque from the second motor, a striker that is selectively reciprocable within the spindle in response to reciprocation of the piston, and an anvil that is impacted by the striker when the striker reciprocates towards the tool bit. The anvil imparts axial impacts to the tool bit.

A workability of a driving work machine is improved by reduction in vibration transmitted to a housing. A driving work machine 10 includes: a cylinder 21 applying a rotational force to a tip tool; a piston 33 applying a striking force to the tip tool; a driving source generating a power; a switching part 61 making switching between at least two operational states including a rotational striking state of transmitting the power as a striking force and a rotational force to the tip tool and a rotational state of transmitting the power as the rotational force but not transmitting the power as the striking force to the tip tool; and a housing 12. The cylinder 21 includes a pushing part 46 pushing the switching part 61 rearward, the switching part 61 is able to switch an operational state of the cylinder 21 by the rearward movement caused by the pushing force of the pushing part 46, and a rubber annular member 72 serving as an anti-vibration part is arranged between the pushing part 46 and the preventing part 71.

An electric power tool includes a motor, a driving side member, and a driven side member. The driving side member and the driven side member have mutually opposed surfaces. A plurality of cam teeth are respectively disposed on concentric circles on the opposed surfaces. The plurality of cam teeth have meshing surfaces inclined at predetermined lead angles. A torque limiter is formed to disengage the engagement of the meshing surfaces of the cam teeth by moving the one member in a separation direction from the other member when load of the driven side member increases. The respective cam teeth are formed such that the lead angles of the meshing surfaces are different between a forward rotation side and a reverse rotation side. A transmission torque transmitted from the driving side member to the driven side member is equal between the forward rotation and the reverse rotation.

A rotary hammer includes a housing, a first motor supported by the housing and defining a first motor axis, a second motor supported by the housing and defining a second motor axis that is coaxial with the first motor axis, and a spindle coupled to the first motor for receiving torque from the first motor, causing the spindle to rotate. The rotary hammer further includes a reciprocation mechanism operable to create a variable pressure air spring within the spindle. The reciprocation mechanism includes a piston configured to reciprocate within the spindle in response to receiving torque from the second motor, a striker that is selectively reciprocable within the spindle in response to reciprocation of the piston, and an anvil that is impacted by the striker when the striker reciprocates towards the tool bit. The anvil imparts axial impacts to the tool bit.

A dust collector includes a body configured to be removably attached to a lower side of a tool body of a drilling tool, a dust storing part to be disposed on a lower side of the body, a sliding part having a suction port and held by the body so as to be slidable in a front-rear direction, a dust transfer passage extending within the sliding part and connecting the suction port and an inlet of the dust storing part, and a tool connection passage disposed within an internal space of the body and configured to connect an outlet of the dust storing part and an inlet of the tool body of the drilling tool. The dust storing part includes the inlet, a filter, a dust storing space and the outlet. The filter is disposed forward of the inlet of the dust storing part.

An electric power tool includes a motor, a driving side member, and a driven side member. The driving side member and the driven side member have mutually opposed surfaces. A plurality of cam teeth are respectively disposed on concentric circles on the opposed surfaces. The plurality of cam teeth have meshing surfaces inclined at predetermined lead angles. A torque limiter is formed to disengage the engagement of the meshing surfaces of the cam teeth by moving the one member in a separation direction from the other member when load of the driven side member increases. The respective cam teeth are formed such that the lead angles of the meshing surfaces are different between a forward rotation side and a reverse rotation side. A transmission torque transmitted from the driving side member to the driven side member is equal between the forward rotation and the reverse rotation.

A hammer drill is provided including a housing, a motor mounted within the housing, and a hammer mechanism. The hammer mechanism includes a crank plate or a wobble plate driven by the motor, a con rod coupled to the crank plate or the wobble plate, a piston reciprocatingly driven by the con rod along a longitudinal axis, a ram and a beat piece. At least one of the wobble plate or the con rod is made of sintered steel.

A power tool having a hammer mechanism includes a tool body defining the driving axis, a motor housed in the tool body, an elongate handle connected to the tool body in a cantilever manner and extending in a direction intersecting the driving axis, and at least one biasing member disposed between the tool body and the handle. The motor has a motor shaft that is rotatable around an axis parallel to the driving axis. The handle includes a first end portion connected to the tool body to be pivotable around a pivot axis relative to the tool body, a free end, and a grip part disposed between the first end portion and a free end of the handle. The at least one biasing member is configured to pivotally bias the tool body and the handle such that the grip part and the tool body move away from each other.

A hammer drill includes a housing inside which a motor, a tubular tool holder, a driving mechanism, a rotation conversion member, and an inner housing are disposed. The driving mechanism is configured to perform at least one of rotation actuation of the tool holder and hammering actuation of a bit. The inner housing supports the driving mechanism, supports the tool holder via a first bearing, and supports an output shaft via a second bearing. The inner housing is divided into a front housing holding the first bearing and a rear housing that is formed in a separate body from the front housing and holds the second bearing. The inner housing is formed by connecting the front housing to the rear housing in an axis line direction of the tool holder. A seal member sealing outside space of the inner housing inside the housing is disposed in the front housing.