为了焊接作业方便 ,设想制作一只“第 3只手” ,用来握住待焊件 ,如图 1所示。用 3根直径和长度适当的圆钢焊成这种工具 ,中间部分需重些 ,顶部制作成钩形状以便钩住待焊件。下面的 2条腿则作为该工具的支承。图 1　“第 3只手”示意试图为焊接作业添加一只“手”![美国] In order to facilitate the welding operation, imagine making a “third hand”, used to hold the workpiece to be welded, as shown in Figure 1. Use 3 rounds of the proper diameter and length to form this tool. The middle part needs to be heavy and the top part made into a hook shape so as to hook the part to be welded. The bottom two legs serve as the support for the tool. Figure 1 “Third Hand” shows trying to add a “hand” to a welding job! [USA]