How pull-bead blackout curtains work?

The pull bead roller blind mainly relies on the transmission of the head part of the upper tube to control the ups and downs of the roller blind. When operating the roller blind mechanism, you only need to pull the pull bead to drive the bead wheel to rotate. At this time, the torsion spring inside the head drives the shaft wheel and the fabric to rotate along the reel It rotates together with the support plate, so that the roller blind fabric moves up and down. When it reaches the top dead center, it stops running, and the same goes for the bottom dead center. After the fabrics are all hung down, due to the gravity of the flat rail and its own gravity, the entire roller blind remains vertical.
The control part of the bead roller shutter mechanism is a torsion spring transmission device, which is generally a universal head. According to the weight and height requirements of the curtain fabric, you can choose a heavy head or a light head, and configure different specifications of the roll tube and fabric.