A dust collection box for a dust extractor includes first and second air inlet chambers, an air inlet aperture through which air is drawn into the first air inlet chamber, an air outlet aperture through which air is dawn out of the second air outlet chamber, an air intermediate chamber formed in the housing, and a filter mounted within the housing. The filter includes a first part through which air passes from the air inlet chamber to the air outlet chamber, and a second part through which air passes from the air inlet chamber to the air intermediate chamber. An ambient air aperture is formed in the wall of the housing. A valve disposed proximate the ambient air aperture is switchable to connect the air intermediate chamber to only one of the air outlet chamber or the ambient air aperture.

A dust collection box for a dust extractor includes first and second air inlet chambers, an air inlet aperture through which air is drawn into the first air inlet chamber, an air outlet aperture through which air is dawn out of the second air outlet chamber, an air intermediate chamber formed in the housing, and a filter mounted within the housing. The filter includes a first part through which air passes from the air inlet chamber to the air outlet chamber, and a second part through which air passes from the air inlet chamber to the air intermediate chamber. An ambient air aperture is formed in the wall of the housing. A valve disposed proximate the ambient air aperture is switchable to connect the air intermediate chamber to only one of the air outlet chamber or the ambient air aperture.

An impact power tool including a housing, a motor supported by the housing, a spindle coupled to the motor for receiving torque from the motor to cause the spindle to rotate, and a reciprocating impact mechanism operable to create a variable pressure air spring within the spindle. The impact mechanism includes a striker received within the spindle that reciprocates along a reciprocation axis in response to the variable pressure air spring, a piston that reciprocates along the reciprocation axis to induce the variable pressure air spring, and a crankshaft configured to convert continuous rotational motion from the motor to reciprocating linear movement of the piston. The crankshaft defines a crank axis perpendicular to the reciprocation axis, and the motor defines a motor axis that is parallel with the reciprocation axis. A center of gravity of the impact power tool is positioned between the motor axis and the reciprocation axis.

A tool-holding apparatus (70) includes an engaging member (71) for engaging a tool accessory (B) and being movably supported in axial and radial directions in a rotational-output shaft (26) having an insertion hole (81) for holding the tool accessory (B). A first biasing member (72) biases the engaging member towards engagement with the engaging member. A bit sleeve (73) is movable in the axial direction along an outer-circumferential surface of the rotational-output shaft between a blocking position at which radial outward movement of the engaging member is blocked and a permitting position at which radial outward movement of the engaging member is permitted. A second biasing member (74) biases the bit sleeve toward the blocking position. A positioning part (75) is fixed on the outer-circumferential surface of the rotational-output shaft and stops the bit sleeve at the blocking position. The bit sleeve has a projection (88), which is disposed on the forward side of the first biasing member, extends inward in the radial direction, and slidably contacts the rotational-output shaft.

A tool-holding apparatus (70) includes an engaging member (71) for engaging a tool accessory (B) and being movably supported in axial and radial directions in a rotational-output shaft (26) having an insertion hole (81) for holding the tool accessory (B). A first biasing member (72) biases the engaging member towards engagement with the engaging member. A bit sleeve (73) is movable in the axial direction along an outer-circumferential surface of the rotational-output shaft between a blocking position at which radial outward movement of the engaging member is blocked and a permitting position at which radial outward movement of the engaging member is permitted. A second biasing member (74) biases the bit sleeve toward the blocking position. A positioning part (75) is fixed on the outer-circumferential surface of the rotational-output shaft and stops the bit sleeve at the blocking position. The bit sleeve has a projection (88), which is disposed on the forward side of the first biasing member, extends inward in the radial direction, and slidably contacts the rotational-output shaft.

A power tool, such as a rotary hammer, includes a housing, an output shaft for mounting a tool accessary and a motor having a motor shaft that generates a rotational output for rotating and linearly hammering the output shaft. The rotational output of the motor shaft is coupled to the output shaft via a driving mechanism that includes a hammer mechanism. An intervening member is axially movable relative to the motor shaft and is operably coupled between the motor shaft and the hammer mechanism. The hammer mechanism and the output shaft are supported by a movable support that is axially movable relative to the housing. Because the output shaft and the driving mechanism are movable relative to the motor and the housing, which preferably includes handle, via the intervening member and the movable support during hammering operations, vibration generated during hammering operations can be dampened before reaching the housing.

A power tool and a safety control circuit module and a safety control method thereof are provided. The power tool includes a power supply device, a control processing device, a safety control circuit module, and a power output device. The control processing device is electrically connected with the power supply device. The safety control circuit module includes a first switch control circuit, a second switch control circuit, a third switch control circuit, a first resistor, and a first diode. The power output device includes a first power connection terminal and a second power connection terminal. Before switch units of the control circuits are controlled, the control processing device detects whether the switch unit has failed, so as to increase safety.

A reducer appropriately selects from three or more variable speeds to match multiple operational modes. An impact driver includes a motor, a reducer that reduces rotation from the motor to select from three or more variable speeds, a plurality of actuators to be actuated by the rotation reduced by the reducer, and a switcher that selects, from the plurality of actuators, a specific actuator to be actuated in a predetermined operational mode. The switcher causes the reducer to cooperate with the selected specific actuator and actuates the reducer at a predetermined variable speed of the three of more variable speeds corresponding to the predetermined operational mode of the selected specific actuator.

Kickback control methods for power tools. One power tool includes a movement sensor configured to measure an angular velocity of the housing of the power tool, and an orientation sensor configured to measure an orientation of the housing. The power tool includes an electronic processor coupled to a switching network and a trigger. To implement the kickback control, the electronic processor is configured to receive measurements of the angular velocity of the housing, receive measurements of the orientation of the housing, determine a binding condition of the power tool based on the measurements of the angular velocity and the measurements of orientation, and control the switching network to cease driving of the brushless DC motor.

Kickback control methods for power tools. One power tool includes a movement sensor configured to measure an angular velocity of the housing of the power tool, and an orientation sensor configured to measure an orientation of the housing. The power tool includes an electronic processor coupled to a switching network and a trigger. To implement the kickback control, the electronic processor is configured to receive measurements of the angular velocity of the housing, receive measurements of the orientation of the housing, determine a binding condition of the power tool based on the measurements of the angular velocity and the measurements of orientation, and control the switching network to cease driving of the brushless DC motor.