Patent ID: 6925719

Claim:
A saw including: a blade assembly having a proximal end; said blade assembly including: an elongate, thin blade having a longitudinal axis including: a proximal end; and a distal end; and a rigid frame including: a proximal end connected to said proximal end of said blade; and a distal end connected to said distal end of said blade; said frame for supporting said blade in tension; a housing including: handle means for holding said saw in a hand; a rotary motor mounted to said housing including: a drive shaft rotating about a shaft axis including: a front end; power means for powering said motor; a piston slideably and non-rotatably supported in said housing including: a front end connected to said proximal end of said blade assembly for moving said blade assembly along the longitudinal axis of said blade coincident with piston movement; and a rear end; and motion converter means for connecting said front end of said drive shaft to said rear end of said piston for converting rotary motion of said drive shaft into reciprocating linear motion of said piston; said motion converter means including: an exterior surface on said drive shaft front end including: a circumferential raceway in a plane at an angle to the shaft axis; a cap on said rear end of said piston having an inside surface; said cap fitting over said exterior surface of said front end of said drive shaft; and coupling means moving in said raceway for coupling with said cap to move said cap.