Method and apparatus for folding carton flaps in a packaging machine

In a packaging machine for folding cartons moving along a carton conveyor, wherein the cartons include major upper and lower flaps, and with the packaging machine having at least one guide with a leading edge, a flap folding apparatus comprising:

• a drive mechanism for driving said folding apparatus;
• a pair of flap folding assemblies, each flap folding assembly comprising a first drive wheel and a second drive wheel spaced from said first drive wheel and connected to said drive mechanism, and each flap folding assembly comprising a vacuum engagement assembly carried by said first drive wheel, said vacuum engagement assembly having a vacuum cup and a support assembly supporting said vacuum cup, wherein selective actuation of said drive assembly causes said first and second drive wheels to rotate simultaneously in the same direction of rotation and simultaneously causes said support assembly to move so that the vacuum cup moves toward said carton conveyor, wherein said vacuum engagement assembly engages the major lower flap while moving downstream with the carton conveyor, wherein said vacuum cup releases the major lower flap when the major lower flap is under said leading edge, and wherein said vacuum assembly then moves upstream with respect to the conveyor to engage another carton on the conveyor;
• and
• a telescopic spline shaft connecting each first drive wheel to said drive mechanism, wherein the length of said telescopic spline shaft is adjustable to accommodate cartons of varying dimensions.