Principles of Operation

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 (Continuous1

II Tractor Gear

Reduction Gear

Paper Drive

P

 

\

PF Motor

 

\

 

\

 

Paper Advance

Paper Drive Roller Gea

 

Reduction Gear

 

 

Platen Gear

Figure 6-7. Pull Tractor Operation Using the Bottom Paper Entrance

Epson FX-870/I 170

6-9