Stacking assembly for a mailpiece sorter

A mailpiece sorting assembly, comprising:

• a feeder module for feeding and singulating mailpieces from a stack of mailpieces, each mailpiece being fed along a feed path in a first on-edge orientation;
• a scanner for reading information contained on each of the mailpieces, and issuing electronic data useful for grouping the mailpieces for delivery;
• a stacker/sorter having a plurality of sortation bins, each sortation bin having a stacking assembly including:
• a Leading Edge (LE) urge roller, a support blade and a Trailing Edge (TE) alignment device,
• the LE urge roller operative to accept each of the selected mailpieces from the re-direct mechanism and urge a leading edge portion thereof toward a sidewall of the sortation bin, the support blade operative to hold the mailpieces in an on-edge parallel orientation against the urge roller and being moveably mounted relative thereto, and the TE alignment device including a first cam driven about a rotational axis by a digital rotary positioning device, the cam defining a surface operative to urge the trailing edge portion of each selected mailpiece toward the support blade and into alignment with the stack;
• a controller operatively coupled to the feeder, scanner and stacker/sorter for sorting mailpieces in to one of the sortation bins;
• and
• wherein the cam surface is defined by the relationship:
• R(θ)=RT/2×(1−COS(π×θ/θT)
• wherein θ is an angle from a line of reference
• wherein R(θ) is a rise height (in inches) at each angle θ;
• wherein RT is a total rise height (in inches)
• wherein θT is a total angle inscribed.