HP C7769B Service Manual - Page 273

Functional Overview Tubes Assembly The Tubes Assembly is the part of the Ink Delivery System which physically drives the ink from the Ink Cartridges in the ISS to the Printheads in the Carriage Assembly. The ink flows through a flexible tube from the ISS to the Carriage by means of the pressure applied by the pumping device in the ISS. Tubes System ISS Crane Clips Carriage Crane In both ends of the tubes there are fluidic interconnections which are designed to prevent any kind of ink leakage, and minimize the ink on customers as they interact with the system (i.e. when they must replace Ink Cartridges or Printheads). While the Ink Cartridges remain static in the ISS, the Carriage goes back and forth along the scan-axis of the Printer. That is why the tubes have to be flexible in order to follow this movement. Since the condition of the ink determines its performance on the printing media (and therefore the print quality output), the Tubes Assembly must guarantee the properties of the ink coming from the Ink Cartridges until it is delivered to the Printheads. This 'healthy' condition is defined by means of maximum water vapor losses and air ingestion that the ink can get along time. HP DesignJets 500 and 800 Series Printers Service Manual 10-9