Patent ID: 6176321
Filing Date: 2001-01-23
Classification: B25D

Abstract:
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.