Method and apparatus for producing glued folded boxes

Abstract

A method and an apparatus for forming the bottom part or cover part of a folded box by means of a plunger which presses a precut blank, the edge portions of which are coated with a liquid adhesive, into a female mold, and wherein means are provided for preventing the marginal strips of the blank which are coated with adhesive from coming in contact with the plunger when the blank is being pressed into and retracted from the mold.

Having thus fully disclosed my invention, what I claim is: 
     
       1. In a method of molding a flat precut blank so as to form a glued folded open box or box cover having a flat bottom or top, respectively, two pairs of opposite side walls connected to said bottom or top .Iadd.and one pair of said walls having vertically arranged end edges.Iaddend., a pair of flaps adjoining the vertical edges at each end of .Iadd.said .Iaddend.one of said pairs of side walls and bent at right angles thereto and extending toward each other into the plane of one of the side walls of the other pair covering said flaps, and a marginal strip adjoining the upper edge of each side wall of said other pair and folded over the upper edges of one pair of said flaps and bent inwardly so as to overlap said upper edges and connect said .[.flap.]. .Iadd.flaps .Iaddend.to each other, wherein before said blank is shaped to form said box or box cover by means of a plunger pressing said blank against a female mold and into a folding recess therein, said marginal strips are coated with adhesive and are bent outwardly mechanically by means of deflectors projecting laterally over said plunger, and wherein after said plunger has been retracted from said mold, said marginal strips are mechanically folded over and glued to the inwardly bent flaps by means of .[.members pivotably mounted on said plunger.]. members .Iadd.pivotably mounted on said mold .Iaddend.. 
     
     
       2. A method as defined in claim 1, wherein before said blank is shaped to form said box or box cover, said other side walls carrying said marginal strips are also coated with adhesive, and wherein while said plunger is moved into said folding recess, said other side walls are held back relative to the first side walls by means of elements which are connected to said plunger. 
     
     
       3. A method as defined in claim 2, wherein while said blank is picked up from a stack of blanks, it is passed in a direction at right angles to and past nozzles from which the adhesive is applied in the form of worms upon the parts of the blank to be coated. 
     
     
       4. In an apparatus for producing a glued folded open box or box cover from a flat precut blank comprising a female mold having a folding recess therein and a plunger adapted to be moved against said mold and into said folding recess, a pair of retaining members, means for connecting said retaining members to said plunger so as to be movable at two opposite sides of said plunger to a limited extent in the direction of movement of said plunger for acting upon parts of said blank adapted to form end walls of said box or cover, and a pair of deflecting members connected to the rear part of said plunger and projecting laterally beyond said plunger. 
     
     
       5. An apparatus as defined in claim 4, further comprising flaplike members pivotably mounted on two opposite lateral front edges of said mold adjacent to said folding recess, and means for pivoting said members so as to fold a marginal strip on each of said end walls of said box or cover over the upper edges of a pair of flaps which are connected to and extend at right angles to the side walls of said box toward each other. 
     
     
       6. An apparatus as defined in claim 4, further comprising a gripping element movable at right angles to the direction of movement of said plunger and having a slot therein into which an edge portion of the blank is inserted, a gripping lever pivotably mounted on said gripping element and adapted to clamp said edge portion, and means for pivoting said gripping lever from its clamping position to a releasing position when said gripping element has been moved to a certain position. 
     
     
       7. An apparatus as defined in claim 6, wherein said gripping lever has a pair of arms, one of said arms being adapted to clamp said edge portion of said blank, and a fixed abutment for pivoting the second arm of said gripping lever so as to release said blank when said gripping member has moved to said position. 
     
     
       8. An apparatus as defined in claim 7, further comprising a release lever pivotably mounted on said gripping element and having one arm engaging upon the second arm of said gripping lever and a second arm adapted to engage upon said abutment for pivoting said gripping lever to release said blank. 
     
     
       9. An apparatus as defined in claim 8, wherein said abutment comprises a curved cam member, and a roller rotatably mounted on said second arm of said release lever and adapted to roll along said cam member. 
     
     
       10. An apparatus as defined in claim 6, further comprising a plurality of nozzles for ejecting an adhesive in a substantially horizontal direction and disposed at such a level that during the movement of said gripping element worms of adhesive will be applied upon said blank of a length substantially equal to the width of said blank. 
     
     
       11. An apparatus as defined in claim 10, wherein the outlet opening of each of said nozzles is spaced at a small distance from the surface of the blank to be coated with adhesive. 
     
     
       12. An apparatus as defined in claim 11, wherein each of said nozzles has an arcuate outer surface, the outlet opening of said nozzle being disposed below the plane in which said nozzle substantially engages with said blank so as to be spaced at a small distance therefrom. 
     
     
       13. An apparatus as defined in claim 12, further comprising an arcuate diaphragm pivotable relative to said nozzle about the center of curvature thereof and having at least one aperture adapted to be moved substantially in aligment with said outlet opening of said nozzle, and means for pivoting said diaphragm in accordance with the movements of said gripping element. 
     
     
       14. An apparatus as defined in claim 6, further comprising a feed member having suction cups for withdrawing a first blank from a stack of blanks located above said female mold and for moving the same into the plane of movement of said gripping element, and pneumatically actuated means for moving said feed member. 
     
     
       15. An apparatus as defined in claim 14, wherein said suction cups of said feed member are adapted to act upon a central part of said blank, and means mounted on said feed member at the opposite sides of said stack for prefolding marginal strips on the opposite ends of said blank relative to the plane of said central part of said blank. 
     
     
       16. An apparatus as defined in claim 4, further comprising deflecting members of a substantially triangular cross section mounted on the rear lateral ends of said plunger and adapted when said plunger is in its forward position within said mold to press against a flat surface on shaft which is preferably provided with needles and on which an L-shaped flaplike member is secured. .Iadd. 17. The improvement of claim 1 wherein said members are actuated to pivot about an axis to bend said strips. .Iaddend..Iadd. 18. In a method of molding a flat precut blank so as to form a glued folded open box or box cover having a flat bottom or top, respectively, two pairs of opposite side walls connected to said bottom or top and one pair of said side walls having vertically arranged end edges, a pair of flaps adjoining the vertical edges at each end of said one of said pairs of side walls and bent at right angles thereto and extending toward each other into the plane of one of the side walls of the other pair covering said flaps, and a marginal strip adjoining the upper edge of each side wall of said other pair and folded over the upper edges of one pair of said flaps and bent inwardly so as to overlap said upper edges and connect said flaps to each other, the improvement comprising coating said marginal strips with adhesive and bending said strips outwardly mechanically by means of deflectors projecting laterally from a plunger, said blank being shaped to form said box or box cover by means of said plunger pressing said blank against a female mold and into a folding recess therein, retracting said plunger from said mold, and mechanically folding said marginal strips over and gluing them to said inwardly bent flaps by means of members pivotably mounted on said mold. .Iaddend. .Iadd. 19. A method of molding a flat precut blank in a machine so as to form a glued folded open box portion having a flat bottom or top, respectively, two pairs of opposite side walls connected to said box portion and one pair of said side walls having vertically arranged end edges, a pair of flaps adjoining the vertical edges at each end of said one of said pairs of said walls and bent at right angles thereto and extending toward each other into the plane of one of the side walls of the other pair covering said flaps, and a marginal strip adjoining the upper edge of each side wall of said other pair and folded over the upper edges of one pair of said flaps and bent inwardly so as to overlap said upper edges and connect said flaps to each other, said method comprising coating said marginal strips with adhesive, bending said strips outwardly mechanically by means of deflectors projecting laterally from a plunger of said machine,   shaping said blank to form said box portion by means of said plunger pressing said blank against a female mold and into a folding recess therein,   retracting said plunger from said mold,   mechanically folding over and gluing said marginal strips to the inwardly bent flaps by pivoting members mounted on the mold against said strips. .Iaddend..Iadd. 20. A method in accordance with the method of claim 19 wherein said members are pivoted about a portion of said mold..Iaddend.