To provide a bottom mechanism on a stretcher which has a bottom full length with allowance in a dorsal posture, in which a leg bottom is sufficiently drawn so as to facilitate standing from a seated posture, a lowest position is made to become lower, and a sitting feeling is improved.SOLUTION: A bottom mechanism comprises: a waist bottom and a back bottom which are attached to an upper part of a support frame； a leg bottom whose one end is attached to the waist bottom； and a coupling arm whose one end is attached to the back bottom and the other end is engaged to the leg bottom. The leg bottom can be rotated in a lower direction according to upward rotation of the back bottom. The leg bottom is formed into a four node link configuration by interposing a link plate between an upper part of the leg bottom which is rotatably attached to a leg side tip end of the waist bottom and a lower part of the leg bottom whose head side tip end is rotatably attached to a leg bracket upper end, so that the lower part of the leg bottom approaches the upper part of the leg bottom and rotates rearward to the upper part of the leg bottom, in linkage with rearward rotation of the coupling arm to a head side in upward rotation of the back bottom from a dorsal posture, for shortening a full length of the leg bottom in a seated posture.SELECTED DRAWING: Figure 8【課題】 仰臥位姿勢でゆとりあるボトム全長とし、座位姿勢で立ち上がり易いように脚ボトムが十分引き込まれ、且つ、最低位をより低くし、座り心地を向上させたストレッチャー等におけるボトム機構を提供すること。【解決手段】 支持フレーム上方に軸着される腰ボトム及び背ボトムと、腰ボトムに一端を軸着される脚ボトムと、一端が背ボトムに軸着され他端が脚ボトムに止着される連結アームによって背ボトムの上方回動に合わせて脚ボトムを下方回動可能に構成するとともに、脚ボトムを腰ボトムの脚側先端に回動可能に軸着される脚ボトム上と脚ブラケット上端に頭側先端を回動可能に軸着される脚ボトム下の間にリンクプレートを介設して四節リンク構成にすることで、仰臥位姿勢から背ボトムの上方回動時に連結アームの頭側への後方回動に連動して脚ボトム下が脚ボトム上に接近しつつ脚ボトム上に対して後方回動することで、座位姿勢時に脚ボトムの全長を短くした。【選択図】図８
