Abstract: It is an object of the present invention to provide an effective technique to alleviate vibration in the electric hammer drill. According to the invention, representative electric hammer drill is provided with a body, a motor, a striker, a cylinder, first and second power transmitting mechanisms, a power switching mechanism, a mode changing mechanism, and a coupling mechanism. The mode changing mechanism is disposed on the upper surface of the body and can change between a hammer-drill mode and a hammer mode. The coupling mechanism is disposed between the mode changing mechanism and the power switching mechanism. The coupling mechanism extends along the peripheral surface of the cylinder and transmits the mode changing movement of the mode changing mechanism to the power switching mechanism by moving in the longitudinal direction of the cylinder.

Abstract: It is an object of the present invention to provide an effective technique to improve ease of operation of the power impact tool. The power tool of the present invention includes a tool body, a tool bit, a motor, first and second switches and a mode changing mechanism. The motor is driven only when both switches are in an on position. The first switch is biased in the off position. The second switch is biased in the last position operated. The mode changing mechanism switches between hammer operation modes such that in the first hammer mode, the user actuates the first switch while the second switch is locked in the on position and in the second hammer mode, the first switch is locked in the on position while the second switch is actuated. In the second hammer mode, actuating the second switch similar to a toggle switch operates the tool.

Abstract: It is an object of the present invention to provide an effective technique to alleviate vibration in the electric hammer drill. According to the invention, representative electric hammer drill is provided with a body, a motor, a striker, a cylinder, first and second power transmitting mechanisms, a power switching mechanism, a mode changing mechanism, and a coupling mechanism. The mode changing mechanism is disposed on the upper surface of the body and can change between a hammer-drill mode and a hammer mode. The coupling mechanism is disposed between the mode changing mechanism and the power switching mechanism. The coupling mechanism extends along the peripheral surface of the cylinder and transmits the mode changing movement of the mode changing mechanism to the power switching mechanism by moving in the longitudinal direction of the cylinder.

Abstract: Accordingly, it is an object of the present invention to provide an effective technique to improve ease of operation of the power impact tool. The representative power impact tool according to the present invention includes a tool body, a tool bit, a motor, first and second switches and a mode changing mechanism. The tool bit performs a striking movement. The motor is driven only when both of the switches are turned on. The first switch is urged from the on position side to the off position side and normally held in the off position. The second switch is turned between the on position and the off position and held in one of the on and off positions unless operated to be turned to the opposite position. The mode changing mechanism switches between hammer operation modes of the tool bit. According to the first hammer mode, the user is allowed to actuate the first switch while the second switch is locked in the on position.

Abstract: A battery pack (1) includes an air intake port (9), air discharge ports (11), first air passages (24), and a second air passage (25). Cooling air introduced into the battery pack through the air intake port (9) flows around and through two cell groups contained in the pack before exiting to the pack from the discharge ports (11). As the intake port and the discharge ports are both provided at an upper enclosure (4) of the battery pack that is set on a charger (50) for charging or an electric power tool as a power source, neither intake port nor the discharge ports are exposed to the exterior environment whether the pack is set on the charger or attached to a power tool.

Abstract: A hammer drill (1) includes an intermediate shaft (13), a clutch ring (25), a second gear (20), and a boss (15) all mounted on the intermediate shaft (13). Also included are a rotatable change lever (40) and a clutch plate (31) which has lock claws (36). When the change lever (40) is fully rotated in the clockwise direction, the hammer drill (1) is placed in a drill-only mode where the clutch ring (25) meshes only with the second gear (20). When the change lever (40) is rotated approximately 45 degrees counterclockwise from the foregoing position, the hammer drill (1) is placed in a hammer drill mode, where the clutch ring (25) meshes with the second gear (20) and the boss (15). When the change lever (40) is rotated approximately another 45 degrees counterclockwise, the hammer drill (1) is placed in a neutral position where tile second gear (20) is disengaged from the clutch ring (25), with the clutch ring (25) remaining in mesh with the boss (15).

Abstract: A bit mounting device is adapted for removably mounting a bit on a tool which has a barrel including a mounting hole adapted for receiving the bit. The bit mounting device includes an engaging member engageable with the bit and a control member mounted on the barrel. The control member is movable between a holding position and a releasing position. The control member in the holding position is operable to fix the engaging member in an engaging position for engagement with the bit. The control member in the releasing position is operable to permit the engaging member to move from the engaging position to a disengaging position for disengagement from the bit. A stopper mechanism is operable to hold the control member in the releasing position when the bit is removed from the barrel.