Cutting rigid and semi-rigid material

摘要

A knife includes a handle enclosing one or more of a blade, a blade shuttle, a transmission, and a trigger, where the handle includes a blade aperture. The blade shuttle is longitudinally moveable relative to the handle from a rest position to a first extended position and the blade shuttle is moveable longitudinally from the first extended position to a cutting position when the blade is engaged in a workpiece. The blade shuttle is automatically retracted from the cutting position to the rest position when the blade is disengaged from the workpiece. The blade is detachably secured within the blade shuttle and protrudes a first distance through the blade aperture at the first extended position. The blade is extended from the first distance a substantially fixed length when engaged in the workpiece. The blade is adapted to automatically retract within the handle when disengaged from the workpiece.