Machine and method for assembling boxes

1. A machine for assembling boxes, the boxes each comprising five independent parts made of a rigid material: two side walls, two head walls and a base with peripheral flanges that engage with grooves in a lower portion of the side walls and the head walls, the head walls having end tongues that are inserted into notches adjacent to ends of the side walls; the machine integrating a central assembly station which comprises:

four feeders of the side walls and the head walls facing each other two by two;

moving means that move the side walls and the head walls from the feeders to lateral edges of the base in a final step of assembly of one of the boxes,

wherein the central assembly station further comprises:

a base ring inside which a stationary forming die is arranged where, on a lower face of the stationary forming die, the base to be formed is placed by a lifting device with vertical mobility in both directions, which moves the base upwards from a lower position to an upper position against the stationary forming die in a first performance, the peripheral flanges protruding from the base with respect to a perimeter of the stationary forming die.

2. The machine for assembling boxes according to claim 1 , wherein the four feeders comprise an inclined structure wherein the side walls and the head walls are arranged in overlapping vertical planes, each of the four feeders comprising pairs of inclined guiding profiles attached by converging lower ends thereof to vertical columns corresponding to four vertical corners of the one of the boxes.

3. The machine for assembling boxes according to claim 2 , wherein the central assembly station comprises push skids that move the side walls and the head walls arranged at lower ends of the four feeders downwards, the inclined guiding profiles having grooved cuts for passage under end sections of the side walls and the head walls to be placed facing the lower windows.

4. The machine for assembling boxes according to claim 3 , wherein the push skids are connected to a head which is vertically movable in both directions, the head being connected to a piston rod of a cylinder located inside a space delimited by the vertical columns above the stationary forming die.

5. The machine for assembling boxes according to claim 4 , wherein the head integrates upper stops and lower stops to compensate for small deformations in the side walls and the head walls.

6. The machine for assembling boxes according to claim 4 , wherein the cylinder arranged above the stationary forming die is affixed to an upper base affixed to upper ends of the vertical columns.

7. The machine for assembling boxes according to claim 3 , wherein lower edges of the side walls and the head walls enter into contact with the base ring when moved downwards by the push skids.

8. The machine for assembling boxes according to claim 1 , wherein the moving means of the side walls and the head walls comprise horizontal push devices which move the side walls and the head walls against the base which is immobilized against the lower face of the stationary forming die.

9. The machine for assembling boxes according to claim 8 , wherein each of the horizontal push devices of the side walls and the head walls comprises a pair of opposed linear actuators by gripping elements that hold each of the head walls and the side walls by two opposite faces thereof, generating a resulting forward movement of a first of the opposed linear actuators with respect to a second of the opposed linear actuators.

10. The machine for assembling boxes according to claim 1 , wherein the central assembly station comprises vertical plates closing spaces delimited between pairs of vertical columns, except for lower windows through which the side walls and the head walls pass during horizontal movement thereof to engage with the peripheral flanges of the base at and end of the assembly of the one of the boxes, where the side walls and the head walls enter into contact with peripheral edges of the stationary forming die.

11. The machine for assembling boxes according to claim 1 , wherein:

the lifting device comprises a linear actuator and a seating platform supporting the base;

the seating platform integrates lugs that are inserted into first holes of the base and also into second holes of the stationary forming die to ensure a better securing and a precise positioning of the base during assembly thereof.

12. The machine for assembling boxes according to claim 1 , further comprising:

a supplying device of bases stacked in overlapping horizontal planes, where the supplying device is arranged in a front area of the machine, before the central assembly station of the boxes;

a terminal station that comprises a box stacker where the boxes that have been assembled are stacked from below;

a lower transporter that drags simultaneously, by a “pilgrim” movement, one of the bases collected from the supplying device and one of the boxes formed in the central assembly station which as been deposited by descent of the lifting device.

13. The machine for assembling boxes according to claim 12 , further comprising a rear station located between the central assembly station and the box stacker.

14. The machine for assembling boxes according to claim 12 , wherein the lower transporter integrates pairs of lateral stops between which one of the bases and one of the boxes supported by the lower transporter are arranged.