PROBLEM TO BE SOLVED: To provide a seedling tray conveyor, for example, adopted for a transplanter for traveling and simultaneously planting seedlings such as vegetable seedlings in a field, which can longitudinally convey a seedling tray at a constant speed.SOLUTION: The seedling tray conveyor of a transplanter includes: longitudinally conveying a longitudinally conveying wheel on the periphery of which many engaging teeth are formed by rotating a distance of one pitch of the engaging teeth disposing a longitudinal conveyance control tool for engaging with the engaging teeth to control the rotation of the tray in the longitudinal conveyance direction of the longitudinally conveying wheel disposing a one-way clutch between the wheel-conveying member and the longitudinally conveying wheel so that the longitudinally conveying wheel is rotated in the same direction as that of the wheel-conveying member, when the wheel-conveying member for rotating the longitudinally conveying wheel in the longitudinally tray-conveying direction is rotated in the longitudinally tray-conveying direction, or the wheel-conveying member is rotated in the direction opposite to the rotation direction of the longitudinally conveying wheel, when the wheel-conveying member is returned releasing the engagement of the longitudinal conveyance control tool with the engaging teeth by the follower-pressing force of a rotary cam, then rotating the wheel-conveying member so that the longitudinally conveying wheel is rotated in a distance of one pitch of the engaging teeth, simultaneously engaging the longitudinal conveyance control tool with a next engaging tooth and returning the follower and the wheel-conveying member to their original positions by the energizing force of a spring, when the cam is separated from the follower.COPYRIGHT: (C)2010,JPO&INPIT【課題】 一定の速さで苗トレイを縦送りさせる。【解決手段】 外周に多数の係合歯が形成された縦送りホイールを係合歯の一ピッチ分回転させることで苗トレイを縦送りし、係合歯に係合して縦送りホイールのトレイ縦送り方向の回転を規制する縦送り規制具を設け、縦送りホイールをトレイ縦送り方向に回転させるホイール送
