Carton squaring mechanism

In a cartoner having a transport conveyor, the transport conveyor comprising opposed pairs of laterally spaced sprockets, spaced parallel endless chains passing around respective pairs of opposed sprockets, each conveyor chain having an upper horizontal run and carrying spaced upwardly-projecting trailing transport lugs, opposed center sprockets disposed between said laterally spaced sprockets and a center endless chain passing around said center sprockets and having an upper horizontal run, said center chain carrying a series of spaced upwardly-projecting leading transport lugs, said center chain being longitudinally adjustable to vary the spacing between the trailing and leading lugs, means for squaring a carton deposited between said leading and trailing lugs, said carton in its flat folded condition having a downwardly-facing leading side wall, said squaring means comprising means for maintaining each said leading lug in a rearwardly-inclined attitude and said trailing lugs in a vertical attitude when on said upper run wherein said leading lug engages the upper corner of said carton between said leading side wall and an upper wall to urge and maintain said carton corners to a right angle attitude.