Saw blade for an electric compass- or keyhole-saw

Claim 1

In combination, an elongated saw blade and a clamping device for an electric compass- or keyhole-saw, said saw blade being provided with a clampable part and a saw part, said saw part including tooth means along a longitudinal edge thereof, said clamping device comprising two clamping pieces having planar surfaces for contacting said saw blade and edges defing longitudinal and lateral directions along said clamping device, said clampable part of said saw blade being clampable with a clamping screw in parallel planar relation between said clamping pieces, and said saw part of said saw blade being located such that the longitudinal axis of said saw part is oriented at an acute angle relative to the longitudinal axis of said clampable part of said saw blade and of said clamping pieces, one of said clamping pieces comprising a clamping part having a centering opening located at half the lateral width of said clamping part as well as a plug or insert opening through which a clamping screw extends, as well as wo clamping tongues extending in the longitudinal direction of the saw blade and defining the limits and boundary laterally as to the plug-insert opening via the two clamping tongues extending equal in length for a satisfactory clamping of the saw blade as well as for taking up reaction forces during saw blade opertion without any danger of breakage of said clamping part and capable of conveying such reaciton forces into the clamping device, said clamping part further comprising: the improvement wherein the ratio of the width of said clamping part measured transverse to the longitudinal direction of the saw blade with respect to the length of the clamping part measured in longitudinal direction of the saw blade from the end of clamping tongues therewith to the end of the tooth means is specifically in a range of 1:1 to 1:1.4; and the ratio of the length of the plug-insert opening to the width thereof lies specifically in a range of 1:0.7 to 1:1.1, and that said clamping tongues respectively are constructed having a squared shape that attains a high strength and security against breakage of said clamping part as well as being able to cope with high load during operation, the plug-insert opening being arranged offset in relation to a longitudinal line passing through the centering opening of the clamping part so that a central longitudinal axis of the plug-insert opening has a lateral spacing from the longitudinal line passing through the centering opening of the clamping part and extends parallel thereto.