A kind of mobile device of apparatus of transport, it can be converted between an expanded position and a stowed position, and include a tray unit, one be mounted on the middle wheel unit of the tray unit bottom end, two be mounted on the left and right sides and the wheel units out of the ordinary with a front-wheel in front of tray unit, and unit taken turns by two Hous being separately mounted at left and right sides of tray unit Hou side and distinctly with Hou wheel, wherein the wheel units and Hou wheel unit all can carry out folding with respect to what tray unit, and the middle wheel that there is unit a tool flexibly to abut ground is taken turns in this. The anti-dumping effect of mobile device and handling thereby can be improved, while reducing the volume of mobile device, to improve convenience when mobile device carries.一種載運工具之移動裝置，可在一展開位置及一收合位置間轉換，並包含一底盤單元、一個安裝在該底盤單元底端的中輪單元、兩個安裝在底盤單元前方左右兩側且各別具有一前輪的前輪單元，以及兩個分別安裝在底盤單元後方左右兩側且各別具有一後輪的後輪單元，其中該前輪單元及後輪單元皆可相對於底盤單元進行收折，而該中輪單元具有一個具彈性地抵接地面的中輪。藉此可提高移動裝置的防傾效果及操控性，同時縮小移動裝置的體積，以提高移動裝置攜帶時的方便性。
