Intermec ColorCoder V4 Service Manual page 58

2.3 Ink Supply System, cont'd.
2.3:B Pump Unit, cont'd.
Intermec ColorCoder V4 – Service Manual Ed. 1
Outline of Operation, cont'd.
Recovery pump
Recovery pump is driven by transmitting power through the one-
way clutch, when the pump motor runs in the direction of
counterclockwise. In the ink circulation and pressure modes, the
recovery pump is, therefore, in the driving operation and in the ink
supply mode stationary. The recovery pump starts running to suc
the waste ink accumulated in the restoration tub and push it back to
the sub-tank. The recovery pump starts running at the same time
when cleaning operation starts and keeps running during stand-by
time after the cleaning, printing operation and a required time to
suck the waste ink in the restoration tub unit. Since the recovery
pump home position sensor detects the location at which the
recovery pump stops, the recovery pump always stops in the open
condition with no roller on the tube.
Filter unit
In the printer, ink recycle system is installed to recycle the ink taking
waste ink appeared through the head cleaning and putting it back to
the ink supply system to re-use. Fine grains and foreign matters
contained in the waste ink need to be removed in order to re-use the
waste ink. The waste ink collected through the recovery pump is
designed to run through the filter unit before running back to the sub
tank, thus, the fine grains and foreign matters are filtered and the
waste ink is reinstated for re-use for printing.
Breather unit
It is very difficult to avoid ink viscosity caused by evaporation, even
if the ink is reinstated through the ink recycle system. The ink supply
system in the printer is air tight structure in order to minimize
viscosity of the ink in the sub-tank. The breather unit is connected
to the sub-tank and has open/close valves (breath valves) and
release valves. The open/close valve is the valve to release the sub-
tank from closed condition and is controlled with the latch solenoid.
The release valve is the valve to balance inside pressure of the
subtank with outside air pressure, when inside pressure is changed
in the subtank, environmental temperature is changed where the
machine is installed and air pressure is changed while the machine
is being transported by air.
Chapter 2 Operation and Timing
57