Davin Toscana-C1b, Service Manual

Page: 311 / 365

No. Component
2 F Feelers x4
3 HT Head Tanks x4
4 --- Filter Units x2
5 H Print Heads x2
6 IM Ink Pump Motors x2
7 CT Print Cartridges x4
An air sensor [1], two feelers [2], and head tank [3] comprise the reservoir of the ink supply system.
The ink flows from the head tank through a filter [4] that contains the piezoelectric element that expands
upon application of a electrical charge to force ink out of the nozzles of the print head [5].
Two ink pump motors [6] drive the simple pump mechanisms that draw ink out of the print cartridges [7]
and send it to the head tanks.
One ink pump motor operates the pumps of two print cartridges. The ink pump motor drives a single worm
gear. The direction of rotation of the gear determines which pump is operated. For example, when the KC
ink pump motor in the illustration above rotates the worm gear forward, the pump draws cyan ink (C) from
the C print cartridge, and when the motor reverses, it draws black ink (K) from the K print cartridge.
The ink pump motor switches on in response to a request for more ink when the ink level sensor detects that
the position of a feeler on the side of a tank indicates that a tank is low. Ink is also drawn into the tank from
the ink supply tubes when the air sensors detect too much air in a tank and not enough ink. The air sensor
activates the air release solenoid which creates a partial vacuum inside the tank that purges the air from
the tank through a vent and at the same time draws more ink from the supply tubes into the tank.
6. Detailed Section Descriptions
310
6