Supporting device and supporting method for articles

A supporting arm for supporting a first article and a second article which is lower than the first article in height, the supporting arm comprising:

• a supporting plate including a first positioning guide or protrusion that positions a bottom of the first article and inhibits horizontal movement of the first article, and a coupling pin that positions a bottom of the second article and inhibits horizontal movement of the second article, the first positioning guide or protrusion and the coupling pin positioning the first article and the second article, respectively, when lowered on the supporting plate and releasing the first article and the second article, respectively, from positioning when elevated;
• a first anti-drop arm that advances over the first article when the first article is positioned by the first positioning guide or protrusion and prevents the first article from elevating and escaping from positioning;
• and
• a second anti-drop arm that advances over the second article when the second article is positioned by the coupling pin and prevents the second article from elevating and escaping from positioning;
• wherein
• the first positioning guide or protrusion is at a higher position than the coupling pin;
• the first anti-drop arm and the second anti-drop arm are at a same side of the supporting plate in plan view;
• the first positioning guide or protrusion and the coupling pin position one end of the first article that is on a side of the first anti-drop arm and the second anti-drop arm to be nearer or equally distant to the first anti-drop arm and the second anti-drop arm than one end of the second article that is on the side of the first anti-drop arm and the second anti-drop arm;
• the second anti-drop arm retracts from the one end of the first article when the first positioning guide or protrusion positions the first article;
• and
• the first anti-drop arm and the second anti-drop arm are separate from one another and do not directly contact each other.