Epson FX-870 Service Manual page 124

Pull Tractor Method
The pull tractor advances paper in basically the same way as the push tractor. The push tractor
is installed at the paper entrance and pushes the paper into the printer mechanism. The pull
tractor, however, is installed at the paper exit and pulls the paper out of the printer mechanism.
As the result, the paper tension unit is not required.
Figure 6-7 illustrates pull tractor operation when the paper is fed through the bottom paper
entrance.
Paper Drive
Paper Drive Roller Gea
Figure 6-7. Pull Tractor Operation Using the Bottom Paper Entrance
Epson FX-870/I 170
Principles of Operation
Paper (Continuous1
II Tractor Gear
Reduction Gear
Paper Advance
Reduction Gear
Platen Gear
6-9