EasyCoder PX4i and PX6i Service Manual 55
Chapter 7 — Transfer Ribbon Mechanism
Working Principles
The ribbon rewind unit is driven by the same motor that drives the platen
roller in the print unit via a belt that engages the timing belt pulley. The
torque spring allows the stepper motor to drive the rewind hub rotate
counter-clockwise only. When the media is fed back, the ribbon will not
move.
The torque spring arrangement automatically compensates for the gradu-
ally increasing diameter of the used ribbon on the rewind hub, so the
ribbon will always be fed at the same speed as the media.
Bobbin
Bobbin plate
Shaft
Timing belt pulley
Flange
Flange
Torque spring
Brake sleeve
Slide bearing
Grub screw
Ball bearing
Locking
washers (x3)
Slide bearing
Ball bearing
Slide
bearing