GB2066727A - Folding a lidded box from a flat blank - Google Patents

Abstract

A flat blank (A) of cardboard, is folded into a box having an integral lid (O) which has a front wall (L) and side walls (J) by a single descending movement of a punch (G) into a former. The element (D2) which folds up the rear wall of the box and a plate (E2) which folds up the front wall (L) of the lid are movable to squeeze the folded corners of the box against its rear wall and tabs (K) on the side walls of the lid against the front wall (L). Adhesive may be applied only at M and N for ease of filling the completed box. The element (F1) is lowerable to enable the finished box to be removed laterally. <IMAGE>

Description

SPECIFICATION A method and apparatus for folding a lidded box from a flat blank, e.g. of cardboard This invention relates to an improved method and apparatus for folding a box from a flat blank of cardboard, or a similar stiffly-bendable sheet material, and more particularly to an improved method and apparatus for manufacturing such a box to have an integral lid with front and side walls to overlap the front and side walls of the box when the box is closed.

Means are already known for automating the production of boxes from flat cardboard blanks, the blanks normally being pre-scored along the subsequent lines of bending and being passed in sequence to a folding press. However, the manufacture of a box having a lid which has front and side walls has hitherto required a sequence of press operations at separate forming stations and a principal object of the present invention is to enable a box and its lid to be formed at the same station and by a single movement of a single punch.Another object of the invention is so to design the former in which the box and its lid are folded to shape by the punch that the operation of gluing folded corners of the box and gluing tabs on the lid side walls to its front wall can be carried out by movable elements of the former after the punch has folded the blank without transfer of the box to another station.

In accordance with one aspect of the invention there is provided a method of folding a flat blank of sheet material, such as cardboard, to the shape of a box having a lid integral with the upper edge of a wall of the box, the lid having a wall to be in overlapping relation with another wall of the box when the box is closed, the method comprising positioning the blank on a former and moving into the former a punch having a leading portion of the shape of the interior of the box and a following portion integral with and laterally offset from the leading portion, the following portion being of the shape of the interior of the lid and the arrangement being such that the box and the lid are successively folded to shape by the punch during a single, continuous movement of the punch into the former.

When the method of the preceding paragraph is applied to the manufacture of a box which has folded and glued corner pieces between adjacent walls and a lid which has a front wall glued by means of folded tabs to side walls thereof, the former employed preferably has elements respectively for folding the rear wall of the box and the front wall of the lid which elements are movable perpendicularly with respect to the direction of movement of the punch, and the method comprises moving said elements toward the punch when the latter has completed its movement into the former so as to squeeze said corner pieces between one of said elements and the leading portion of the punch and squeeze said folded tabs between the other element and the following portion of the punch.

In accordance with another aspect of the present invention there is provided apparatus for carrying out the method defined in either of the two immediately preceding paragraphs, the apparatus comprising a former and a punch reciprocable between a retracted position and an operative position within the former, the punch having a leading, box-forming portion and a following, lid-forming portion integral with the box-forming portion and offset rearwardly and laterally with respect to the latter, the former comprising a pair of box side wall folding elements spaced apart for passage therebetween of the punch, box front and rear wall folding elements transverse to the box side wall folding elements and disposed further from the retracted position of the punch than the box side wall folding elements, the box rear wall folding element being movable toward the box front wall folding element from a retracted position in which the leading portion of the punch may pass with clearance between the box rear and front wall folding elements, a pair of lid side wall folding elements and a pair of lid side wall tab folding elements disposed above the box rear wall folding element, said pairs being spaced from one another and from the pair of box side wall folding elements with respective elements of said three pairs generally in alignment, and a lid front wall folding plate disposed above the box rear wall folding element between the tab folding elements and movable relative to the latter in a direction parallel with the direction of movement of the box rear wall folding element.

In order to enable cardboard boxes to be folded in rapid succession, the blanks are taken, e.g. by a suction device, from a stack, after which they are transported by a conveying chain to a position immediately in front of the punch. From the conveying chain they are pushed by a feed device into a position underneath the punch, after gluing points have first been given an application of glue by an upwardly moving gluing finger. To ensure that the blanks will in all cases assume the correct position underneath the folding punch, stops, e.g.

of L-shape, are mounted on fixed elements of the former.

The gluing points are preferably confined to the two corners iof the cardboard box which are adjacent the lid and to the two tabs of the lid side walls. In order to enable the finished open cardboard box, after the folding and after any gluing operations, to be withdrawn laterally of the former without difficulty, one of the lid side wall folding elements is preferably designed so that it can be lowered alongside the box rear wall folding element. To enable a machine to be provided which operates automatically, driving and control means can be provided to ensure mutually coordinated and automatic movements of the punch and the movable elements of the former in the required sequence.

The accompanying drawings provide schematic diagrams of five successive phases of the use of one embodiment of apparatus in accordance with the invention. In the drawings: Figures 1-5 show the apparatus in each case as seen from the side, the punch being shown in vertical section; and Figures 1 a-5a show in each case a plan view of the apparatus, the punch being shown in horizontal section.

Underneath the offset lower, leading part G1 of a folding punch G a former for a cardboard box comprises elements D, and D2 for folding up the front wall and the rear wall, respectively, of the box and above and at right-angles to them spaced apart elements D3 for folding up the box side walls. Underneath the offset higher part G2 of the punch G the area of the former for folding the lid of the box is located over the horizontally displaceable element D2. A pair of fixed elements E1 are positioned to fold up tabs K, a pair of elements F, are positioned to fold up the lid side walls and a plate E2 is horizontally displaceable on the side member D2 between the elements E1 to fold up the front wall of the lid.A blank A of cardboard has been fed forward by a pusher (not shown) from a conveyor (likewise not shown) and is guided by guide bars B until it contacts Lshaped stops C, thus reaching its correct position on the former. The areas of the blank A which will form the sides of the cardboard box are marked H, the front wall of the box and rear wall of the box I, the side walls of the lid J, the front wall of the lid L, the gluing tabs of the lid side walls K and lid as a whole 0. Between the walls H and I of the cardboard box are corner parts i, which in the course of the folding process bend inwards, owing to the diagonal scoring or grooving to which they have been subjected. Gluing points on the corner parts i of the cover are marked M, while gluing points on the tabs K are marked N.

In the first phase of the lowering of the punch G, as shown in Figure 2, the lower part G1 of the punch G presses downwards the part of the blank A which will form the floor of the box. In this process the side walls H of the cardboard box first of all come in contact with the elements D3 of the former, being bent up as the punch continues to descend.

In the subsequent phase, shown in Figure 3, the front wall I of the cardboard box and the rear wall I of the cardboard box come in contact with the upper edges of the elements D1, D2 of the former and are pressed upwards. In this process the corner parts i of the cardboard box bend, the elements D3 preventing them from deflecting outwards and the punch G preventing them from deflecting diagonally inwardly of the box. With the rear wall I of the cardboard box the lid O of the cardboard box likewise slants upwards. The following, offset part G2 of the punch G is not yet in contact therewith.

As the punch continues to descend as shown in Figure 4 its lower part G1 erects the front I of the cardboard box completely and the rear wall I of the cardboard box only partly, since while the punch G is descending the distance between the elements D1 and D2 is somewhat greater than the intended front-to-rear wall dimension of the cardboard box. At the same time the upper, offset part G2 of the punch contacts the lid 0 and presses the latter downwards. In this process the lid side walls J come in contact with the elements F1, F2, and are bent upward and the tabs K are bent obliquely inwards by the end edges of the elements E, of the former and the front wall L of the lid is bent obliquely upwards by the upper edge of the plate E2.

Figure 5 shows the position reached by the cardboard parts when the punch G has completed its operating stroke. By the simultaneous movement of the plate E2 and the element D2 in the directions shown by the arrows, the cardboard box and its lid are caused to assume their final rectangular shapes in which process the gluing points K and M are pressed against each other, thus producing a cardboard box of which the front wall I can still be opened up, which is in many cases of advantage for the subsequent filling operation. After the box has been filled the front wall I of the box is held by the front wall L of the lid so that the corner parts i adjacent to the said front wall I of the box do not have to be glued. If desired, however, these corner parts i can likewise be provided with gluing points. The gluing is then automatically effected in the same operating stroke with that of the other gluing points.

In order to enable the finished open cardboard box to be removed from the former without difficulty, one of the elements F1 can be lowered, as shown by the broken lines in Figure 5. The cardboard box can then be pushed out to a filling station by means of a pusher operating from the opposite side transversely to the direction in which the blank A was fed into position.

Claims (9)

1. A method of folding a flat blank of sheet material, such as cardboard, to the shape of a box having a lid integral with the upper edge of a wall of the box, the lid having a wall to be in overlapping relation with another wall of the box when the box is closed, the method comprising positioning the blank on a former and moving into the former a punch having a leading portion of the shape of the interior of the box and a following portion integral with and laterally offset from the leading portion, the following portion being of the shape of the interior of the lid and the arrangement being such that the box and the did are successively folded to shape by the punch during a single, continuous movement of the punch into the former.

2. A method as claimed in claim 1 for the manufacture of a box which has folded and glued corner pieces between adjacent walls and a lid which has a front wall glued by means of folded tabs to side walls thereof, wherein the former employed has elements respectively for folding the rear wall of the box and the front wall of the lid which elements are movable perpendicularly with respect to the direction of movement of the punch, the method comprising moving said elements toward the punch when the latter has completed its movement into the former so as to squeeze said corner pieces between one of said elements and the leading portion of the punch and squeeze said folded tabs between the other element and the following portion of the punch.

3. Apparatus for carrying out the method claimed in claim 1 or claim 2, the apparatus comprising a former and a punch reciprocable between a retracted position and an operative position within the former, the punch having a leading, box-forming portion and a following, lidforming portion integral with the box-forming portion and offset rearwardly and laterally with respect to the latter, the former comprising a pair of box side wail folding elements spaced apart for passage therebetween of the punch, box front and rear wall folding elements transverse to the box side wall folding elements and disposed further from the retracted position of the punch than the box side wall folding elements, the box rear wall folding element being movable toward the box front wall folding element from a retracted position in which the leading portion of the punch may pass with clearance between the box rear and front wall folding elements, a pair of lid side wall folding elements and a pair of lid side wall tab folding elements disposed above the box rear wall folding element, said pairs being spaced from one another and from the pair of box side wall folding elements with respective elements of said three pairs generally in alignment, and a lid front wall folding plate disposed above the box rear wall folding element between the tab folding elements and movable relative to the latter in a direction parallel with the direction of movement of the box rear wall folding element.

4. Apparatus as claimed in claim 3, wherein the tab folding elements are provided with stops for limiting movement onto the former of the blank while the punch is in its retracted position.

5. Apparatus as claimed in claim 3 or claim 4 and additionally comprising means for applying to the balnk prior to folding spots of adhesive confined to the corners of the portion of the blank which will form the box adjacent the portion of the blank which will form the lid and to tabs of the blank which extend from the areas of lid portion of the blank which, when folded, will form the side walls of the latter.

6. Apparatus as claimed in any one of claims 3 to 5, wherein at least one of the lid side wall folding elements is movable from its operative position above the box rear wall folding element to an inoperative position alongside the latter to permit removal laterally of the former of the finished box.

7. Apparatus as claimed in any one of claims 3 to 6, and comprising means for controlling the movements in the required sequence of the punch and of the movable components of the former.

8. A method of folding a flat blank of sheet material, such as cardboard, to the shape of a lidded box substantially as described in the Description.

9. Apparatus for carrying out the method claimed in any one of claims 1, 2 and 8 substantially as described in the Description with reference to and as shown in the accompanying diagrammatic drawings.

-10. A box made by the method or by means of the apparatus claimed in any one of the preceding claims.