arch spring fastening

例句：

1. 1.The arch spring fastening on the door is holding it securely shut.
   门上的拱形弹簧紧固装置正牢固地关闭着。
2. 2.The arch spring fastening on the roof is holding up the whole structure.
   屋顶上的拱形弹簧紧固装置支撑着整个结构。
3. 3. The arch spring fastening on the wall is holding up the plaster.
   墙上的拱形弹簧紧固装置正在支撑石膏。