Patent ID: 6213222
Filing Date: 2001-04-10
Classification: B25D

Abstract:
A drive mechanism for a power tool, the power tool including a housing, a motor supported by the housing and connectable to a power source, the motor including a rotatably driven drive shaft, and a support member supported by the housing, the support member being adapted to support a tool element so that the tool element is movable relative to the housing, the tool element having an axis and being driven by the power tool to work on a workpiece, said drive mechanism for imparting an axial motion on the tool element, said drive mechanism comprising:a drive mechanism housing connectable to the housing of the power tool;a first cam member rotatably supported by said drive mechanism housing and having at least one first cam surface, said first cam surface being oriented at a steep angle with respect to the axis of the tool element;a second cam member rotatably supported by said drive mechanism housing and having at least one second cam surface engageable with said first cam surface, said second cam surface being oriented at a corresponding steep angle with respect to the axis of the tool element, said second cam member including an impacting surface for engaging the tool element to provide an impact; anda gear assembly supported by said drive mechanism housing and being drivingly connectable between the drive shaft and said first cam member and between the drive shaft and said second cam member so that said first cam member and said second cam member are counter-rotatable;wherein, as said first cam member and said second cam member counter-rotate, said first cam surface and said second cam surface engage so that said second cam member is axially moved in a direction relative to said first cam member; and wherein, as said first cam member and said second cam member continue to counter-rotate, said first cam surface and said second cam surface disengage so that said second cam member is axially moved in an opposite direction relative to said first cam member to provide an impact on the tool element.