Xerox Phaser 4500 Service Manual page 49

Theory of Operation
Front
s4500-020
Extension lock The 150-sheet tray extends to accommodate different paper
lengths. The extension lock holds the extension in position.
End guide The end guide can be adjusted to different paper sizes by making a
forward or backward adjustment. It makes contact with the rear end of the
paper, and holds the paper in position front-to-back in the paper tray.
Through the cam action of the sector gear and size rack, the position of the
end guide is converted to up and down combinations of the three size switch
links on the side of the tray. The links, when in contact with the paper size
switches in the left tray guide, turn the switches on or off in combinations that
correspond to the paper size.
Phaser 4500/4510 Service Manual 2-13