Brother MFC9100C Service Manual page 26

The purge cam is so designed that:
- the carriage lock pops out to lock the carriage before purging and pops in before cleaning with
the wiper,
- the purge cap comes out and becomes pressed against the nozzle ends of an ink-jet unit,
- the pump works to draw out ink from the head nozzles and drains it into the ink absorbers,
and
- the head wiper comes out to clean the nozzle surface.
A sequence of the above operations is carried out by one rotation of the purge cam. The home
position of the purge cam is detected by the HP switch. For the purge cam HP switch, refer to
Section 2.3.
(1) Carriage lock
If the purge cam is driven, the carriage lock of the purge unit pops out and locks the carriage to
align a particular ink-jet unit with the purge cap during purging operation. After purging but before
cleaning with the wiper, it pops in to release the carriage. When the power is off, the carriage lock
keeps the print head pressed against the head cap.
(2) Pressing the purge cap against the nozzle ends
The purge cap comes out and becomes pressed against the nozzle ends of an ink-jet unit.
(3) Purging
If activated, the pump draws out ink from the head nozzles and drains it into the ink absorbers to
remove air bubbles or dust from the inside of the nozzles and channels.
(4) Cleaning with the head wiper
After purging operation, the wiper comes out and the carriage moves from the right to left so as to
clean ink remaining on the head surface.
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