Upper Transport - Pitney Bowes DM300c Service Manual

3.4 Envelope/
Tape Transport
DM300c/DM400c/DM475 Service Manual (SV61801 Rev. D)

Upper Transport

The transport drive motor is
mounted on the rear plate of
the machine. It turns clock-
wise as seen in Figure 3-5,
driving the main shaft that
runs from the rear to the front
of the printer, through a se-
ries of pulleys and belts (fig-
ure, right.) A pulley pinned to
the front of the shaft drives a
segmented feed belt which,
in turn, drives a segmented
feed (first feed) roller and
intermediate feed roller.
To assure reliable belt track-
ing, the feed belt has a center
ridge that rides in the center
groove of each pulley of the
upper transport. The idlers
of the lower transport are
friction-driven by the feed
components of the upper
transport. See Figure 3-6,
right.
3 • Theory Of Operation
Main Drive
Shaft
Figure 3-5 Transport Drive Train (from Rear)
Belt Tensioner
Drive Pulley
for Segmented
Feed Roller
Figure 3-6 Upper Transport Feed Belt
Motor Pulley
Exit Roller
(not Visible)
Drive Shaft
3-9