Spring box for vertically displaceable rolling shutter, has snap fastener blocking rotation of outer flange during breaking of spring whose curved end is enclosed by prongs in slits arranged in rims of inner flanges

摘要

The spring box has an outer flange (2) rotating with respect to a fixed shaft, and a spiral spring compensating weights of a rolling shutter using the flange. A snap fastener cooperates with a notch of a notched wheel (7) and blocks the rotation of the outer flange during breaking of the spring. A curved end of the spring is enclosed by prongs (23, 24) in slits (21, 22) arranged in rims of an inner flange (19). Independent claims are also included for the following: (A) a method for assembling a spring box of a fall prevention device for a vertically displaceable rolling shutter (B) a tool for assembling a spring box of a fall prevention device for a vertically displaceable rolling shutter.