Service manual
3 • Theory Of Operation
3-10 DM300c/DM400c/DM475 Service Manual (SV61801 Rev. D)
Figure 3-9 Lower Transport Jam Lever, Cover
and Transport
3.4 Envelope/
Tape Transport
✍
TIP: See section 3.10
for DM475 differences
and specific theory.
Interlock. A jam lever sensor is
mounted on the sensor board
below transport sensors PS2
and PS3. See Figure 3-42. As
the transport is locked, the lock
lever slide moves a rotating flag
to block the jam lever sensor
(see Figures 3-8 and 3-12). The
mailing machine will not oper-
ate when the transport is open
(sensor unblocked). In this case
the machine displays the Jam
Lever Open error message.
The figure at the right (for
DM300c) shows how the jam
lever, lower transport cover and
transport mechanism go togeth-
er. The sensor board connects
to the main logic board at J119.
Figure 3-8 Lower Transport Locking Mechanism
Lock Lever Slide
Locking Cam
Lower Transport
The lower transport assembly is
hinged to the right and left side
plates by means of two pivot
studs. The assembly is equipped
with a lock lever that allows the
user to lower the transport for
jam clearance.
Rotating the lock (jam) clockwise
moves the lock lever slide to the
left. This motion first releases
the torsion springs that hold the lower transport rollers up. Next, the two white
can rollers arrive at the edge of the cams that hold the lower transport up and the
weight of the lower transport is transferred to the locking cam that rests against
a ramp on the inside of the bottom cover of the printer. As the lock lever slide
completes its movement to the left, it continues to rotate the locking cam which,
in turn, allows the lower transport to drop down by gravity. When the lock lever is
then rotated in the counterclockwise direction, the process is reversed.
The lower transport consists of
six idler rollers, a segmented
idler that opposes the upper
transport’s segmented feed roller,
and an envelope ski. See Figure
3-7 above. The lower transport
is entirely passive; that is, it is
driven by the upper transport and
contains no motors or sensors.
Figure 3-7 Top View of Lower Transport Re-
moved from Machine, Cover Off