back-moving spring

例句：

1. 1. The back-moving spring is responsible for the smooth operation of the door.
   后移弹簧负责门的平滑操作。
2. 2. The retractable spring is a convenient feature that allows you to store it when not in use.
   可伸缩弹簧是一个方便的特性，允许你在不使用时将其存储起来。
3. 3. The retracting spring is designed to be easily replaced without having to disassemble the entire mechanism.
   回缩弹簧设计得易于更换，无需拆卸整个机构。