Rotary blade A1 is extending radially outward from the fixed position of the holding member 100 is the distal end side and the holding member 100 which is rotated is attached to the mounting shaft 14 of the brush cutter, base end and held by the holding member 100 and a, (4a) and cord-shaped cutting member 4 to. A main body portion 120 and 130, which rotates integrally with the mounting shaft 14, the holding member 100, the combined relative rotation operably 14 around the mounting shaft and movable in the axial direction of the mounting shaft 14 with respect to the main body section 120 and 130 an operation unit 140, an elastic member 170 for biasing the one direction in the axial direction of the operation unit 140, and the main body portion 120 when the operation portion 140 in place by the elastic force of the elastic member 170 operation unit 140 a clutch mechanism for allowing relative rotation between the body portion 120 and the operation unit 140, main body when it is possible to prevent relative rotation, it was moved from the predetermined position operation unit 140 against the elastic force of the elastic member 170 a reel member 160 are combined so as to be rotatable about a mounting shaft 14 for 120 parts, the winding holding the cord-shaped cutting member 4, the transfer of rotating the reel member 160 in response to the rotational operation of the operation unit 140 I and means.回転刃A1は、刈払機の取付け軸14に取付けられて回転させられる保持部材100と、保持部材100に基端側が保持され、かつ先端側が保持部材100の一定位置から半径方向外方に延出するコード状切断部材4(4a)と、を備える。保持部材100は、取付け軸14と一体回転する本体部120,130と、本体部120,130に対して取付け軸14の軸方向に移動可能かつ取付け軸14周りに相対回転操作可能に組み合わされた操作部140と、操作部140を上記軸方向の一方方向に付勢する弾性部材170と、操作部140が弾性部材170の弾力によって所定位置にあるとき操作部140と本体部120,130との相対回転を阻止するとともに、操作部140が弾性部材170の弾力に抗して上記所定位置から移動させられたとき操作部140と本体部120,130との相対回転を許容するクラッチ機構と、本体部120,130に対して取付け軸14を中心として回転可能に組み合わされ、コード状切断部材4を巻回保持するリール部材160と、操作部140の回転操作に応じてリール部材160を回転させる伝達手段と、を備える。
