Tension Servoed, Variable Torque, Center Driven Ribbon Control Transmission
Original Publication Date: 1988-Oct-01
Included in the Prior Art Database: 2005-Feb-15
This device provides a servoed tension control for typewriter and printer ribbon spool on both the input and take-up sides of the printhead. The device which drives a ribbon spool 10 includes an input drive gear 12, drivingly engaging a carrier gear 14. The carrier gear 14 rotatably mounts a plurality of circumferentially spaced planet gears 16 on gear posts 18. The planet gears 16 drivingly engage an output gear 20 and a ring gear 22, the output gear being connected to drive the spool 10 by drive lugs 24 and the ring gear 22 being rotatable. A tension control arm 26 is pivotally mounted on pivot pin 28 and has a tension control brake 30 formed at one end thereof which engages the ring gear 22. The other end of the control arm 26 has a shaft 32 which rotatably mounts a ribbon roller 34.