METHOD AND DEVICE FOR PRODUCING PAPER OR CARDBOARD BOX LIDS AND/OR BOX BOTTOMS

Abstract

A method and device for producing boxes is provided. The boxes include a cut-out shape in the form of the bottom or the lid, with a lateral wall. The lateral wall is formed from a strip having a beginning, an end, and connection tongues. Then, the beginning of the strip is applied and fixed to the lateral surface of a cylindrical female mould having a cross-section corresponding to the cross-section of the box, by means of a male mould. Then, the female mould is turned. The strip is sucked onto the lateral surface and held in place by means of a vacuum. After an adhesive has been applied to the beginning or end of the strip, the beginning and end of the strip are stuck together. Then, a cut-out shape in the form of the bottom or the lid is pressed onto the connection tongues.

Claims

1. A method for producing paper or cardboard box lids and/or box bottoms with a lid or bottom blank and a sidewall attached thereto, the method comprising: providing a strip with a beginning, an end, and connecting tabs on a long side as the sidewall; bending the connecting tabs by up to 90 degrees; placing the strip against the lateral surface of a cylindrical female mold, whose cross section corresponds to a cross section of the box, with the aid of a traveling ram as the male mold; connecting the strip beginning and the strip end; placing the lid or bottom blank on the connecting tabs; connecting the connecting tabs to the lid and bottom blank; fixing temporarily the strip beginning to a section of the female mold; rotating the female mold, wherein the strip is suctioned onto the lateral surface of the female mold and is held in place; and breaking the vacuum and removing the finished box part from the female mold after the connecting tabs are connected to the lid or bottom blank.

2. The method according to claim 1, wherein, for the boxes, whose cross section has more than one concave section and more than one convex section, the method comprises: placing the strip beginning on a concave section of the lateral surface with the help of the male mold; rotating the female mold to the next concave section of the lateral surface; and repeating the placing and rotating steps according to the number of concave sections along the box periphery.

3. The method according to claim 1, further comprising attaching the strip beginning to a concave section of the lateral surface via a vacuum.

4. The method according to claim 1, wherein the strip beginning is placed on a concave section of the female mold.

5. The method according to claim 1, further comprising: applying adhesive to the connecting tabs before the pressing on.

6. The method according to claim 1, further comprising: temporary fixing an interior mirror blank to the bottom of the female mold via a vacuum.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0031] FIG. 1 shows a lower part of a box with a star shape; and

[0032] FIG. 2 shows the elements of a device for producing the star-shaped paper or cardboard boxes according to FIG. 1.

DETAILED DESCRIPTION

[0033] FIG. 1 shows purely schematically the bottom part of a paper or cardboard box with a star shape. Box shapes of this type are often used for chocolates. Boxes may also have the shape of a Christmas tree, Santa Claus, an Easter bunny, an Easter egg, an apple, or also a heart. All of these box shapes have in common that they cannot be produced with box erecting devices that are known and have proven to be effective for cubic boxes.

[0034] As FIG. 1 shows, the depicted bottom box part has a bottom blank 2 made of paper or cardboard, on which there is a sidewall, having a paper or cardboard strip 1, which is glued to form a ring by means of overlapping at strip beginning 4 and is then glued onto bottom blank 2. Connecting tabs 3 are provided for gluing. It is also possible however to glue strip 1 in a butt-joint manner to base 2. If connecting tabs 3 are not to be visible, a so-called interior mirror 5 (only shown in areas) is glued in.

[0035] The apparatus illustrated purely schematically in FIG. 2 for the production of the bottom box part shown in FIG. 1 has a female mold 10 and a male mold 20 as the major components.

[0036] Female mold 10 forms the heart of the device. A cylinder is evident whose base area corresponds to box 1, 2 to be produced; therefore it is also star-shaped. Openings 12 are provided in areas in lateral surface 11 of female mold 10. These can be connected to a vacuum source (not shown) via vacuum connections. It is possible in this way to shape strip 1 into a sidewall by means of vacuum at lateral surface 11 of female mold 10 and to fix it in position until bottom blank 2 is glued on. A guide edge 15 guarantees the exact position of strip 1 along female mold 10.

[0037] The production of a matching box lid occurs basically in the same manner. Nevertheless, a female mold with matching dimensions must be used. Therefore, it is of great advantage that female molds 10 can be quickly replaced.

[0038] To be able to detect whether strip 1 lies correctly on lateral surface 11 and closes openings 12, pressure sensors can be inserted into the vacuum lines. If the nozzles suck in air, the low pressure in the line drops, which is detected by the pressure sensors and reported.

[0039] As can be seen in FIG. 2, strip 1 with already folded down connecting tabs 3 is pushed forward until strip beginning 4 encounters a stop 30. Male mold 20 then travels downward and positions strip beginning 4 precisely in one of the recessed sections of the star-shaped female mold 10. There, strip beginning 4 is held in place by a vacuum nozzle.

[0040] Next, female mold 10 is turned with the help of its connecting axis 14, to which it is attached replaceably. In so doing, strip 1 is wound onto lateral surface 11 and shaped. If necessary, the winding and shaping are supported by male mold 20 traveling back and forth in a controlled manner.

[0041] As soon as strip 1 has been wound totally onto female mold 10, the end of the strip is pressed against strip beginning 4 with the help of male mold 20, until the previously applied adhesive has hardened. It is basically possible to apply the adhesive as a continuous bead to bottom blank 2 and/or interior mirror 5. It is substantially better, however, when the adhesive is applied precisely metered in a punctiform manner to the front and/or back side of connecting tabs 3; however, because of the plurality of connecting tabs 3 and the high working speed of modern machines, this imposes high requirements on hardware and software.

[0042] Next, a bottom blank (not shown) can be removed from a tray in a manner known per se with the aid of a vacuum arm. Said bottom blank is now pressed with the help of the arm onto female mold 10, connecting tabs 3, and strip 1, forming the sidewall, until the previously applied adhesive has hardened. Next, the completed box is removed from female mold 10 with the help of the same or different vacuum arm, whereby the removal process is supported in that air is blown out of vacuum nozzles 12, 13.

[0043] Vacuum nozzles 13 provided in the base of female mold 10 have the task of holding in place interior mirror 5, which is placed on female mold 10, before strip 1 has been wound onto lateral surface 11.

[0044] The supplying of the vacuum to vacuum nozzles 12, 13 occurs through a vacuum rotary feedthrough integrated into the axis of rotation 14.

[0045] The trays, which stock the blanks for the sidewall, bottom, and interior mirror, are not shown in the drawing. The devices that remove the blanks from the trays and supply them to the processing stations are likewise not shown. The vacuum source is also not shown. These functional elements are realized by conventional technology. Their illustration would make the drawing unclear and thereby incomprehensible.

[0046] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.