PROBLEM TO BE SOLVED: To unlock a turning mechanism by one hand to proceed as it is to turning operation of a grip portion, and to provide a turning mechanism at low cost by reducing the number of components thereof.SOLUTION: When installing the grip portion through the turning mechanism on one side part of a fixed fence portion, the turning mechanism is configured such that an externally toothed plate is fixed to the fixed fence portion, wherein the external tooth plate is to mesh with an internally toothed plate fixed at the lower end of a support pipe installed in a vertical direction of the grip portion, that the grip portion is designed to be freely vertically slidable, and that operation is made possible between two states of a state in which a lock plate comes into contact with the upper end of the support pipe and a state in which the lock plate retreats from the sliding region of the support pipe by pressing the unlocking button.COPYRIGHT: (C)2012,JPO&INPIT【課題】片手でロック解除でき、そのままグリップ部の回動操作もできるようにするとともに、この回動機構の構成部品数を少なくすることにより安価に提供すること。【解決手段】固定柵部の一側部に回動機構を介してグリップ部を設けるに、この回動機構は、グリップ部の上下方向に設ける支持パイプの下端に固着した内歯プレートと噛合する外歯プレートを固定柵部に固着するとともに、グリップ部が上下に摺動自在となるよう構成する一方、前記支持パイプ上端にロックプレートが接触する状態とロック解除ボタンを押すことでこのロックプレートが前記支持パイプの摺動域から退避する状態とに操作可能に構成した。【選択図】図6
