초록 ▼

A power-driven hammer drill 1 includes a rotary lever 8 for transmitting and disabling the transmission of the rotation of a motor 5 to a tool bit 4 and a slide lever 9 for transmitting and disabling the transmission of hammer blows to the tool bit 4. The rotary lever 8 is formed with a chamfer 52,

A power-driven hammer drill 1 includes a rotary lever 8 for transmitting and disabling the transmission of the rotation of a motor 5 to a tool bit 4 and a slide lever 9 for transmitting and disabling the transmission of hammer blows to the tool bit 4. The rotary lever 8 is formed with a chamfer 52, whereas the slide lever 9 is formed with a straight portion 54 and a cut-out 53 which conforms to the circular edge of the rotary lever 8. When the slide lever 9 is in the lowermost position with the rotary lever 8 fitted in the cut-out 53, the rotary lever 8 is in the position to disconnect the rotation of the motor 5 to the tool bit 4, and while in this position, the slide lever 9 cannot be slid to its uppermost position, in which hammer blows cannot be transmitted to the tool bit 4. When the slide lever 9 is located in the uppermost position and the chamfer 52 of the rotary lever 8 is in the rearmost position, in which hammer blows cannot be transmitted to the tool bit 4 but rotation can be transmitted to the tool bit 4, the straight portion 54 opposes the chamfer 52 across a narrow gap so that the rotary lever 8 cannot be rotated to the rotation disabling position.

대표청구항 ▼

[ What is claimed is:] [1.] A hammer drill, comprising:a chuck mounted on a front end of the hammer drill;a motor for providing drive power for the chuck;a rotation transmission mechanism provided between the chuck and the motor for transmitting rotation of the motor to the chuck;an impact transmiss

[ What is claimed is:] [1.] A hammer drill, comprising:a chuck mounted on a front end of the hammer drill;a motor for providing drive power for the chuck;a rotation transmission mechanism provided between the chuck and the motor for transmitting rotation of the motor to the chuck;an impact transmission mechanism provided between the chuck and the motor for transmitting hammer blows generated by the motor to the chuck;a first change-over member associated with the rotation transmission mechanism for selectively enabling and disabling the rotation transmission mechanism to transmit the rotation of the motor to the chuck;a second change-over member associated with the impact transmission mechanism for selectively enabling and disabling the impact transmission mechanism to transmit the hammer blows generated by the motor to the chuck;a manually operable first operating member movable between operative and inoperative positions, wherein the first operating member, when in the operative position, operates the first change-over member so as to enable the rotation transmission mechanism and, when in the inoperative position, operates the first change-over member to disable the rotation transmission mechanism;a manually operable second operating member movable between operative and inoperative positions, wherein the second operating member, when in the operative position, operates the second change-over member so as to enable the impact transmission mechanism and, when in the inoperative position, operates the second change-over member to disable the impact transmission mechanism; anda lock means for, when one of the first and second operating members is in its inoperative position, coordinating with the other operating member so as to prohibit the other operating member from moving to its inoperative position.