Sheet feeder with stack-holding tray having flexible-band-coupled guide elements

Apparatus for holding a stack of sheets for entry into a sheet feeder, comprising:

• a tray for vetically supporting said stack,
• left and right stack guide elements moveable toward and away from the lateral edges of said stack for centering said stack in said tray,
• extensions of said stack guide elements that extend below said tray,
• a flexible band formed in a loop,
• said band being attached at a first location to a first of said extensions and a second location to the second of said extensions, said second location being about halfway around said loop from said first location, such that said stack guide elements move inward and outward laterally in unison,
• band guide elements at the lateral edges of and below said tray,
• said band guide elements having slot means for vertically restraining said band, and
• band-bending means for bending said band during inward movement of said stack guide elements so that when said movement stops the band tends to move said stack guide elements outwardly as it assumes an equilibrium position, thereby preventing overtightening of said stack guide elements against said stack.