Brother PT 1800 - P-Touch 1800 Thermal Transfer Printer, Service Manual

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II - 3
2.1.2 Platen and Tape Feed Sub Roller Setting & Retracting Mechanism
This mechanism consists of the roller release lever, roller release rod, and roller holder
ASSY.
The roller holder ASSY supports the platen and the sub roller holder so that:
• the platen can move perpendicularly to the thermal head and rotate freely and
• the sub roller holder can move perpendicularly to the tape feed roller.
The sub roller holder supports the tape feed sub roller so that the roller can rotate freely.
Closing the cassette cover pushes down the roller release lever which moves the roller
release rod to the left (when viewed from the front of the machine). This pivots the roller
holder ASSY around the shaft provided on the chassis so as to press the roller holder
ASSY against the thermal head.
The platen is pressed perpendicularly against the thermal head with the tape and ink
ribbon (only the tape when using non-laminated thermal film tape cassettes or stamp
tape cassettes) sandwiched inbetween under a uniform load by the platen spring. Also,
the sub roller holder is pressed so that the tape feed sub roller is pressed perpendicularly
against the tape feed roller built in the tape cassette with the tape (the laminate tape and
adhesive base tape when using laminated tape cassettes) sandwiched inbetween by the
sub roller holder springs and at the same time the tape feed sub roller's gear becomes
engaged with the tape feed gear.
Opening the cassette cover retracts the roller holder ASSY from the thermal head,
providing you with enough space to replace the tape cassette.
Figure 2.1-2 Platen and Tape Feed Sub Roller Setting & Retracting Mechanism