The case packer presented a design challenge for Custom Building Products to develop a machine that could accept a range of sizes and styles. The crux of the solution was an interchangeable cartridge-type disappearing guide system created by S.V. Dice Designers. The cassette fits flush inside a 20 x 20 metal plate that forms the product accumulation chamber. Each of the cassettes guides align with a corresponding metal sideplate that delineates each infeed lane; it is also at a right angle to the cross-pusher mechanism that propels the bottle group into the case. The cassette prevents bottles from running into the accumulation chamber as one big nest of products that may jam. What makes the design ingenious is that changeover of the package-specific product accumulation chamber is tool-less. Weighing about 25 lb each cassette comprises a 18 x 15 x 6 metal assembly with retractable guides or parallel bladestwo three or fourthat extend 1½ above the assemblys surface. The cassettes blades continue the infeed lanes just upstream. When the bottles are in position and ready for side-loading into the awaiting case the blades retract. The pneumatic cross-pusher then pushes the bottles across the cassette surface/deadplate and into the case through a funnel. When the bottle width/pack pattern changes the cassette is switched out. Five different cassettes are used. To change the cassette the operator releases four toggle clamps and uses an air-operated elevator to raise the cartridge above the loading level. It is then exchanged for a new cartridge that is lowered and clamped into position. Assistant plant manager Tom Milan says that they make a changeover at least once a day and have changed up to four times daily. Changeovers to larger containers take 30 minutes whereas changes to smaller ones take an hour.