Patent ID: 7047651

Claim:
A power compass saw ( 10 ) with a housing ( 12 ) that accommodates a lifting rod for the up and down movement of a longitudinal saw blade ( 27 ) attached thereto, the saw blade having a toothed side and a saw blade back ( 270 ), and with a guide roller ( 29 ) which serves as reciprocating stroke-support roller, supports the saw blade back ( 270 ) and has a central circumferential groove ( 290 ) into which the saw blade extends with its saw blade back ( 270 ) and is guided therein, whereby the sides of the circumferential groove ( 290 ) are tapered wherein the saw blade back ( 270 ) of the saw blade is designed with a 7° conical configuration and/or taper on both sides defining edges, so that it tapers toward the saw blade back ( 270 ) and is capable of being supported in two dimensions in the circumferential groove ( 290 ), the groove sides ( 291 ) of which have a 5° taper, wherein the saw blade back ( 270 ) measured at cone and/or taper edges is wider than the groove bottom ( 292 ) of the circumferential groove ( 290 ) of the guide roller ( 29 ), no wider than 1.5 mm, wherein the groove bottom ( 292 ) is less wide than the saw blade back ( 270 ), not wider than 1.4 mm, and wherein the guide roller ( 29 ) has a diameter of 10 to 25 mm, and the groove is as deep as possible, at least 5 mm deep.