Carton forming machine

In an apparatus for forming a knock-down preglued box from a preformed blank having a center panel, a pair of opposed foldable side flaps, a pair of opposed foldable end flaps, and opposed pairs of front and rear foldable corner tabs which are connected to and project sidewardly from the opposite edges of the end flaps, the improvement comprising:

• frame means;
• elongated guide means movably supported on said frame means and defining a horizontally elongated path along which the blank is moved, said guide means including a pair of elongated parallel guide rails which are horizontally spaced apart and are slidably supported on said frame means for slidable movement toward and away from one another to vary the transverse spacing therebetween;
• said guide rails being of an L-shaped cross section at least adjacent the inlet end of said apparatus, each guide rail including a vertically projecting leg for slidably guiding an edge of the blank and a horizontally projecting leg fixedly connected to and projecting inwardly from the vertical leg adjacent the lower end thereof, the horizontal legs of said opposed guide rails projecting inwardly toward one another and defining thereon upper horizontal support surfaces for slidably guiding said blank;
• adjustment means drivingly interconnected between said guide rails for simultaneously moving same in opposite directions to selectively vary the transverse spacing therebetween;
• folding means disposed adjacent but spaced inwardly from the inlet end of said apparatus for engaging the front corner tabs and folding same upwardly so as to partially overlap the center panel as the blank is movably displaced along said guide rails, said folding means including a pair of identical folding devices which are spaced adjacent the opposite sides of said path and are individually mounted on the respective guide rails;
• a pair of adhesive-applying devices mounted on said guide rails at a location downstream of said folding means, each said adhesive device including a downwardly directed discharge nozzle for directly adhesive onto one of the side flaps of the blank;
• sensing means positoned for sensing the leading edge of the blank as it is moved along said path for activating said adhesive devices;
• and
• side flap folding structure disposed downstream of said adhesive devices for engaging the side flaps and folding same upwardly so as to overlap the center panel and the previously folded corner tabs, said folding structure including a pair of folding members disposed for engaging the flaps on the opposite side of said blank, each of said folding members being mounted on a respective one of said guide rails.

In an aparatus for forming a knock-down preglued box from a preformed blank having a center panel, a pair of opposed foldable side flaps, a pair of opposed foldable end flaps, and opposed pairs of front and rear foldable corner tabs, the improvement comprising:

• frame means;
• elongated guide means mounted on said frame means and defining an elongated path along which said blank is moved;
• drive means extending longitudinally of said path for moving said blank therealong;
• first folding means disposed adjacent said path for automatically folding the front corner tabs upwardly so as to partially overlap the blank as it is moved along said path by said drive means, said first folding means being nonpowered and comprising a pair of identical folding devices which are positioned adjacent the opposite sides of said path for simultaneously engaging and folding the pair of front corner tabs;
• each said folding device including tab deflecting lever means supported for pivotal movement about a substantially horizontal axis which extends substantially perpendicular to the direction of movement of the blank, said tab deflecting lever means being normally maintained in a first position wherein the upstream end of the lever means projects into the path of movement of the front corner tab as the blank advances along said path from the inlet end thereof, whereby engagement of said front corner tab with said lever means as said blank is advanced along said path causes said lever means to be swingably displaced into a second position wherein the front corner tab is displaced vertically from the path so that the remainder of the blank can freely pass by the lever means on the side thereof which is opposite the front corner tab;
• each said folding device also including a stationarily positioned reaction structure positioned closely adjacent but slightly vertically spaced from the respective lever means for confining the front corner tab therebetween;
• each said folding device further including a folding element disposed directly downstream of said lever means for engaging a front corner tab after it has been deflected by said lever means and folding same over so as to at least partially overlap said blank;
• hold-down means disposed directly downstream of said folding element for engaging and holding the front corner tab in its folded-over position;
• means positioned downstream of said first folding means for applying adhesive to one of said flaps or said folded corner tabs;
• and
• second folding means positioned downstream of said first folding means and coating with an opposed pair of said flaps for folding same upwardly and inwardly so as to overlap said center panel and the previously folded corner tabs.