我们在某电厂修整钢窗启闭机构时,发现因年久,很多螺丝钉锈住退不出,常被拧断在边框上,见图1。我们当时在10多米的高空作业,既无手电钻可用,又无丝锥可供重新攻丝,移位操作又不方便,因窗 When we were repairing the opening and closing mechanism of a steel window in a power plant, we found that because of the long years, many screws could not retreat from the rust, and they were often twisted on the frame. See Figure 1. We were working at a height of more than 10 meters at the time. There were no hand drills available, and no taps were available for re-tapping. The shift operation was inconvenient.