PROBLEM TO BE SOLVED: To provide a metallic circular saw that smoothly enables mowing in the grass mixed of Japanese silver grass and small woods like a perfect circle circular saw blade and a chip saw, continues high mowing performance for a long time without being greatly worn away like the perfect circle circular saw blade in a short time in the soil with a lot of sand gravel, and also facilitates toothing without nicks like the chip saw.SOLUTION: Multiple arc blades for a brushcutter include: multiple cutting edge guards formed on the same circle multiple circular arc parts provided in the rotation direction side from the cutting edge guards, having a rotation direction leading portion inside from the circle, and continued to the cutting edge guards in the rear tail side while gradually approaching the circle from the leading portion and multiple inclined parts provided in an anti-rotation direction side from the cutting edge guards, and continued to the circular arc part in the end side from the rear tail part of the cutting edge guards while being gradually spaced from the circle. Multiple cutting blades are cut out and formed in the circular arc part, and the multiple circular arc parts are in a positional relationship of rotation symmetry to each other.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2016,JPO&INPIT【課題】 真円丸鋸刃やチップソーのようにススキや小径木が混じるような叢もスムーズに刈払いが可能で、砂礫の多い土壌でも真円丸鋸刃のように短時間で大きく摩耗することなく、長時間高い刈払い性能を持続し、チップソーのように刃こぼれもすること無く、目立ても容易な金属製の丸鋸の提供。【解決手段】 同一円周上に形成された複数の刃先ガードと、前記刃先ガードより回転方向側に設けられ、前記円周よりも内側に回転方向先頭部分を有し、該先頭部分より徐々に前記円周に近接しながらその後尾側で前記刃先ガードへと連続する複数の円弧部と、前記刃先ガードより反回転方向側に設けられ、前記刃先ガードの後尾部より徐々に前記円周より離間しながらその後端部側で前記円弧部へと連続する複数の傾斜部を備え、前記円弧部には複数の刈刃が切り欠き形成されているとともに、複数の前記円弧部は互いに回転対称の位置関係にある刈払機用複数円弧刃。【選択図】 図1
