Genicom 3600 - Manual (Page 157)

Appendix
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This appendix describes the theory of operation for the 3600 printer.
Functional Description of the 3600 Mechanics
This section describes the basic mechanical functionality of the 3600 printer.
The 3600 printer has a sheet metal frame (base plate and main deck plate) to
which mechanical and electrical components are attached. The printer holds,
moves, routes for contact by the printhead, and stores label stock and ribbon by
electronically controlled mechanical means. Sheet metal covers protect media
and components.
The printer has one electrically powered motor that is the source of
simultaneous movement for all of the driven parts. The motor shaft uses a
pinion gear to impart drive force to the rotating parts, producing ribbon and
liner movement.
The motor pinion gear drives the platen roller by meshing with the 96-tooth
gear mounted on the end of the roller. The platen roller gear contacts a 96-tooth
gear/pulley assembly on the TTR drive roller, assisting ribbon movement and
providing drive to the TTR takeup hub by means of the drive belt (O-ring)
between the TTR drive gear/pulley and the TTR takeup clutch/pulley.
The motor pinion gear also meshes with a 96-tooth gear/pulley on the liner
drive roller, assisting liner movement and providing drive to the liner takeup
hub by means of another drive belt between the liner drive gear/pulley and the
liner takeup clutch/pulley.
The liner takeup clutch/pulley rotates an idler shaft and gear that meshes with
an identical gear on the liner takeup hub shaft to produce reverse rotation of
the liner takeup hub.
The TTR drive function and the liner drive function each use one-way clutches
to facilitate label retract. A one-way clutch is part of each roller drive gear. The
TTR drive roller gear is white, while the liner drive roller gear is black. This
makes it easy to distinguish between the two gears, which is necessary because
the clutches are one-way in opposite directions and would not work if
interchanged.
The clutch/pulley assemblies on the TTR takeup hub and liner reverse shaft
are similarly color coded because they have different torque values. The
springs inside are color coded as well: TTR = white gear, white pulley/clutch,
white spring (inside); liner = black gear, black pulley/clutch, black spring.
The belt driven TTR takeup (16 in-oz) hub and liner reverse (34 in-oz) idler
shaft use one-way clutches that manage takeup force and prevent slackening
during retract. Reversed liner takeup rotation produces less slippage.
The TTR supply hub uses an 18 in-oz slip clutch. The hub has a TTR encoder
sense label attached to it that is used for ribbon motion sensing.