Functional Overview

Tubes System

The Tubes System is the assembly that performs these functions:

nConduct the ink pumped from the Ink Cartridge to the Printhead.

nConduct the air from the pump into the Ink Cartridge.

nKeep the ink in good condition until it is delivered to the printhead.

nAvoid 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:

nSupport the tubes in both directions: horizontal and vertical.

nProvide an adequate sliding surface for the tube carrier.

nAllow 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:

nBase 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.

nProtection 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:

nProtect the tubes from wear and to keep them in order.

nKeep a low friction coefficient.

nAvoid push-pull forces being transmitted to the tubes.

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HP DesignJets 1050C and 1055CM Printers Service Manual