not to interfere with translational forces exerted by the upper compression belt 17 and delivery belt 13 the cyclic operation of the interrupter arm assembly 22 is more fully illustrated in fig3 the upper compression belt 17 has a variably extendable section 24 extending over the next section a dual position delivery table 26 the downstream end roller 25 of this section 24 is mechanically biased e g spring biased to keep the stack 16 in compression on the delivery table 26 until it enters a strapping system 27 where it is bundled for transportation the delivery table 26 is positioned with its conveyor belt on top see fig6 to convey the stacks 16 to the strapping system 27 fig2 shows the delivery system in shingle output delivery mode here the stack conveyor 9 has been lowered to a level below the delivery belt 39 s entry end roller 15 and the delivery section main frame 11 translated via the wheels 12 upstream to a position adjacent to the transfer section 3 lowering of the stack conveyor 9 places it in a non interfering position relative to translation of the main frame 11 translated upstream via the wheels 12 to a position adjacent to the transfer section 3 it could also be swung aside or otherwise placed in a noninterfering position among the other adjustments made to accomplish mode conversion is the lowering of the downstream end of the delivery section and raising of the entry end roller 15 the exit end roller 28 and the lower support rollers 14 however at least one section of lower support rollers 14 at either end are lowered out of contact with the delivery belt 13 to provide the belt 13 with compliant entry and exit sections.