Tubes system – HP 1055CMHP User Manual
Page 292
Functional Overview
10-6
HP DesignJets 1050C and 1055CM Printers Service Manual
Tubes System
The Tubes System is the assembly that performs these functions:
n
Conduct the ink pumped from the Ink Cartridge to the Printhead.
n
Conduct the air from the pump into the Ink Cartridge.
n
Keep the ink in good condition until it is delivered to the
printhead.
n
Avoid leaks and minimize ink on customer.
The main functional groups of the Tubes System assembly are the
tube routing, the tubes and the printhead fluid interconnect.
The tubes move back and forth inside the volume defined by the
tube guides. The Tube guides are a pair of sheet metal parts with
opposing U-shaped profiles. The tubes are constrained inside them,
which helps avoid kinks. The main functions of the tube guides are:
n
Support the tubes in both directions: horizontal and vertical.
n
Provide an adequate sliding surface for the tube carrier.
n
Allow easy access to the tubes in the event of replacement.
Due to fatigue stress limitations, the space between the tubes and the
guides is a compromise between stress on the tubes and space
available.
The tubes are routed in a horizontal loop and go over the carriage.
The tubes are threaded inside a protective extrusion called the Tube
Carrier. The tube carrier is a co-extruded part with two different
materials that have two different functions:
n
Base material. This material provides the structure of the part. It
is rubber-like to avoid contributing too much in forces over the
carriage. The material is cheap and fatigue resistant, but its high
coefficient of friction and low wear resistance makes it
inappropriate for use in the Tube Guides.
n
Protection ribs. The Tube carrier profile outer parts that are
susceptible to rubbing need to be protected. These ribs are made
from a hard plastic with exceptional wear properties and a very
low coefficient of friction.
The main functions of the tube carrier is to:
n
Protect the tubes from wear and to keep them in order.
n
Keep a low friction coefficient.
n
Avoid push-pull forces being transmitted to the tubes.