Capping Mechanism - Epson Stylus COLOR 440 Service Manual

EPSON Stylus COLOR 440, 640, and 740

Capping Mechanism

The capping mechanism seals the printhead when the printer is not in
use. This prevents the ink from thickening due to continuous exposure
to the air. Also, the capping mechanism creates a vacuum seal around
the printhead, which enables ink suctioning to take place.
Included in the capping mechanism is an air bleed value. See Figure
2-14. During high-power suctioning, the bleed value is kept closed.
This enables the pump to generate maximum suction. During medium-
and low-power suctioning, the carriage moves all the way to the right,
pushing the valve release pin against the frame of the capping
mechanism. This opens the bleed valve and reduces vacuum pressure
in the cap.
Valve-Closed
Position
Printhead guides
Ink drain
hole
Air bleed
hole
Bleed valve
Valve closed
Valve release pin
Figure 2-14. Capping Mechanism - Bleed Valve Operation
Chapter 2 Operating Principles
Valve-Open
Position
Cap
Valve open
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