Patent ID: 6035945
Filing Date: 2000-03-14
Classification: B25D

Abstract:
A hammer drill having a motor, a rotation transmitting mechanism transmitting a rotational force to a tool attached to said hammer drill, and a percussion mechanism transmitting a percussion force to said tool, said rotation transmitting mechanism comprising:a pinion disposed on an intermediate shaft so as to be rotatable about said intermediate shaft and slidable in an axial direction along said intermediate shaft;a first sleeve fixed to said intermediate shaft; anda first clutch mechanism selectively engaging said pinion with said first sleeve to transmit a rotational force of said motor to said tool, and disengaging said pinion from said first sleeve to interrupt the transmission of the rotational force to said tool;said percussion mechanism comprising:a second sleeve supported around said intermediate shaft, said second sleeve being non-rotatable with respect to said intermediate shaft but slidable axially along said intermediate shaft;a motion converting member rotatable supported on said intermediate shaft, said motion converting member converting the rotational force of said motor into the percussion force; anda second clutch mechanism selectively engaging said motion converting member with said second sleeve to transmit said percussion force to said tool, and disengaging said motion converting member from said second sleeve to interrupt the transmission of said percussion force to said tool, andsaid hammer drill further comprising:a first spring interposed between said second sleeve and said pinion, said first spring applying a bias to both of said second sleeve and said pinion;a rotation restricting member axially slidable along said intermediate shaft to shift said pinion and said second sleeve;a second spring for applying a bias to said rotation restricting member; anda third clutch mechanism for engaging said rotation restricting member with said pinion.