PROBLEM TO BE SOLVED: To provide a mechanism for making jammed grass smoothly get out to lengthen the life of a clutch by solving the problem that during cutting with a bush cutter, grass cut down by a cutting blade is jammed between the top face of the cutting blade and the rear face of a safety cover top plate by driving rotation of the cutting blade.SOLUTION: A shaft is provided substantially parallel to a rotary surface of a cutting blade in a side view in a part between an operation rod 3 and a cover top plate part, and the cover top plate part and the peripheral edge plate part can be turned around the axes thereof roughly in the vertical direction of the rotary surface of the cutting blade to enlarge and reduce the interval between the rotary surface of the cutting blade and the rear face of the cover top plate and the interval between the knife edge of the cutting blade and the peripheral edge plate. When grass is jammed, a lever fitted to a handle part or the like is operated to separate the rear face of the cover top plate and the peripheral edge plate from the rotary surface of the cutting blade and the knife edge of the cutting blade so that the jammed grass is made to get out behind the rotation of the cutting blade.【課題】刈払機で刈り払い中に、刈刃が刈り倒した草を刈刃の駆動回転で刈刃上面と安全カバー天板裏面間に詰まらせてしまう。その詰まった草を円滑に脱出させ、クラッチの寿命を延ばす機構を提供する。【解決手段】操作棹3とカバー天板部との間の一部位に、側面視で刈刃回転面と概ね平行に軸を設け、カバー天板部と周縁板部をその軸を中心にして刈刃回転面に対して粗垂直の方向に回動させ、刈刃回転面とカバー天板裏面との間隔及び刈刃刃先と周縁板との間隔を拡縮することが出来るようにする。草が詰まったとき、ハンドル部等に取り付けたレバーを操作して、カバー天板裏面・周縁板を刈刃回転面・刈刃刃先から離し、詰まった草を刈刃回転の後方へ脱出させる。【選択図】図4
