Broken tail pull and shell rupture
1. the installation dimension does not match the use environment → hard pull (the minimum installation dimension of the environment is greater than the minimum installation dimension of the push rod) → hardtop (the maximum installation dimension of the environment is less than the maximum installation dimension of the push rod)
2. structure interference → dead angle in front and rear pull rotation of push rod → interference between push rod and bedstead → large deviation of front and rear hole center of push rod during installation (slot structure)
3. Other reasons → damage caused by impact → serious overload → improper installation
