< Topic >Although being simple structure, it is possible, to suppress the movement of the suffering inspection person where the physique differs securely furthermore operativity is satisfactory and the installation and removal easy safe shoulder guard is offered.SolutionsTo have the tightening screw 7 which, the side edge 14b of top board 14 of the x-ray device holding is done in the applied part to be concatenated 2 which installation and removal possibly is installed and applied part 2 to this side edge, 14b gearing surface direction having the gearing section of the pair which is parallel or vertical vis-a-vis the surface of top board 14 and the claw clutch the push button 9 which entrance ardently is done and, in the time dynamic section one end to be concatenated transmission of 8 which transmits time power unidirectionally and this time power 3 which consists of and time dynamic section 3, focusing on the time driving axle of claw clutch 8 the time dynamic possible armThe shoulder guard section 6 which is installed in the other end of 4 and arm 4 and, it has.< Choice figure >Drawing 1【課題】簡易な構造でありながら体格の異なる被検者の移動を確実に抑制することが可能であり、しかも操作性が良好で着脱容易な安全肩当てを提供する。【解決手段】X線装置の天板14の側端縁14bを挟持する締付ネジ7を備え,この側端縁14bへ着脱可能に装着される装着部2と、装着部2に連結され、噛合面方向が天板14の面に対して平行又は垂直である一対の噛合部を備えて一方向に回動力を伝達する噛合いクラッチ8と,この回動力の伝達を入切する押ボタン9と,から成る回動部3と、回動部3に一端が連結され,噛合いクラッチ8の回動軸を中心に回動可能なアーム部4と、アーム部4の他端に取り付けられる肩当て部6と、を備える。【選択図】図1