PROBLEM TO BE SOLVED: To provide a device which assures switching operation of a clutch, in a uniaxially or coaxially normal and normal/reverse switching rotary transmission device.SOLUTION: The switching device includes: a manual operation part which operates an operation wire with an operation lever provided to a steering wheel beyond a fulcrum so as to carry out the switching operation, through the reciprocating action of a reciprocating clutch 23, to the normal and normal/reverse switching gears 27, 28 in the uniaxially and coaxially normal and normal/reverse switching rotary transmission device which is driven by the power of the engine of a tiller an operation transmission part which transmits the action of the manual operation part to the reciprocating clutch 23 through the operation wire and a clutch operation part C equipped with the reciprocating clutch 23 which slides a reciprocating cylinder body 11 formed with a rotary cam slope 13 through the action of the operation transmission part, by the rotation of a rotary center shaft 10 having a slope pressing pin 14 and draws the reciprocating clutch 23 with the shift fork 12 of the reciprocating cylinder body 11 on both sides to switch the rotary transmission to both the switching gears 27, 28 of the rotary transmission device.COPYRIGHT: (C)2012,JPO&INPIT【課題】一軸上ないし同軸上正転並びに正逆転切換えロータリ伝達装置において、確実なクラッチの切換え操作が可能となる装置を提供する。【解決手段】耕耘機のエンジンの動力で駆動される一軸上ないし同軸上正転並びに正逆転切換えロータリ伝達装置における正転と正逆転の切換ギヤ27、28への切換え操作を往復クラッチ23の往復作動で行うために、運転ハンドルに設けた操作レバーで操作ワイヤを支点越えさせて操作する手動操作部と、手動操作部の作動を操作ワイヤを介して往復クラッチ23へ伝達する操作伝達部と、操作伝達部の作動で回転カム斜面13を形成した往復筒体11を、斜面押圧ピン14を備えた回転中軸10の回動でスライドさせて往復筒体11のシフトフォーク12で往復クラッチ23を両側に寄せ付けてロータリ伝達装置の両切換ギヤ27、28への回転伝達の切換えをする往復クラッチ23を備えたクラッチ作動部Cとから成る。【選択図】図5