Box forming apparatus with extensible wing elements

A box forming apparatus for forming a box from a pressed cardboard blank which has been introduced on a forming matrix. The apparatus has two rectangular end plates joined together by a bridge by means of a guide and bolt system in each plate. The guide and bolt system permits variation and adjustment of the height of the apparatus with regard to the machine support. Two winged plates are pivotally attached between the end plates, the winged plates pivoting freely without the aid of pistons or springs. The respective axes of rotation of each of the wings is located at their respective top edges. The pivoting of the wings is delimited by round profiles, or stops, located on the end plates at two separate locations. One set of the stops prevent motion inward towards the center of the end plates, while a second set of stops prevent motion outward away from the center of the end plates. The wings have a bevelled bottom edge for relatively free sliding motion as the wings contact the cardboard blank.

OBJECT OF THE INVENTION 
As is expressed in the title of this specification, the present invention 
refers to some improvements introduced in cardboard box forming machines, 
and as such, they provide a series of relevant features regarding present 
conventional machines used for the same purpose. 
The object of the present invention consists of designing a new extensible 
forming element used in this type of machine, that is introduced in a 
matrix upon which the cardboard box is formed, with the particularity of 
being simple, extensible and interchangeable for different sizes of boxes. 
BACKGROUND OF THE INVENTION 
Presently a multitude of machines designed to form cardboard boxes from 
previously pressed flat sheets are known. These machines all coincide in 
the way of forming the box. The former is introduced in a matrix upon 
which the box is formed and the box is subsequently ejected. 
The circumstance that the former is extensible is due to the need to reduce 
its size in order to come out of the matriz once the box has been formed 
when the box has horizontal bridges. If the box does not have horizontal 
bridges, the former could be stationary, in other words, not extensible. 
Presently, extensible formers have complicated pneumatic expansion devices 
that have bearings, pneumatic cylinders, etc. and besides they are not 
interchangeable; in other words, as there is a large number of 
measurements of boxes it is necessary to have the corresponding formers. 
If we take into account the number of sizes of boxes that exist, we are 
talking about having an infrastructure of spares which is enormous with 
all the inconveniences that this involves. 
DESCRIPTION OF THE INVENTION 
In order to avoid the above cited problems, the new analysis shatters the 
present concept of extensible core. 
This is structurally studied to endure the pressures of the different box 
forming devices and at the same time it has an extensible device without 
pneumatic or similar elements. 
This extensible former is formed by two rectangular wings that pivot 
regarding the top edge thereof, these being articulated by both top ends 
with some opposite vertical plates, joined together by a bridge, by means 
of a guides system located in the inside wall of each plate that permits 
variation of the height regarding the machine support. 
The bottom ends of these wings are prepared so that upon descending and 
coming in contact with the bottom of the box to be folded, they open and 
pivot up to a stop formed by a bar situated at a certain height, between 
the vertical plates. 
Once the box has been formed, the former rises, closing the wings by 
gravity until another established stop, without ever troubling the 
horizontal bridges of the formed box. 
This extensible former is capable of covering all extensible measurements 
of boxes with only for or five spares, it even being able to be fixed upon 
the side plates being joined by means of a top sheet, as an interior top 
surface. 
In order to provide a better understanding of the features of the invention 
and forming an integral part of this specification, some sheets of 
drawings in whose figures, the extensible former object of the invention 
has been represented in an illustrative and non-restrictive, have been 
attached hereto.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Making reference to the numbering used in the figures, the improvements 
introduced in cardboard box forming machines, are mainly centered on the 
extensible former comprising two parallel opposite rectangular plates (1, 
2), joined together by a bridge (3) or a fixed sheet (4) as an interior 
top surface. 
The bridge (3) is formed by a rectangular prismatic body which fits in each 
end in some vertical guides made in the inner wall of each plate (1, 2.) 
This bridge (3) has a variable height upon being able to slide vertically 
between the guides, assuring its position by means of bolts (5.) When the 
former has this bridge (3), it can be said that it has a variable height 
since the vertical displacement of the same regarding the machine support 
can be varied upon varying the height of the bridge (3) in terms of the 
plates (1, 2.) 
In the event that the plates (1, 2) are joined at the top by a sheet (4) as 
an interior top surface, the former is stationary, given that the above 
cited height cannot be varied. 
In both cases, between the plates (1, 2) there are two wings (6, 7) 
consisting of a flat surface that can have a rectangular plan shape with a 
large inner opening like the one shown in FIG. 1, or a "U" shape like the 
one shown in FIG. 6. In both cases, the bottom edge is bevelled, and the 
rectangular or "U" shape is justified to reduce weight. 
These wings (6, 7) pivot from the ends of their top edges in terms of a 
horizontal rotation axis (8, 9) between the plates (1, 2) at a certain 
height. The wings (6, 7) have their pivoting delimited by some round 
profiles located between the same and at different heights. Each wing (6, 
7) has its own profiles (10, 11, 12 and 13 respectively), of the limiting 
of the pivoting thereof. 
With this arrangement of the former, it can be said that it is extensible, 
given that upon descending joined to the machine support, the wings (6, 7) 
will slide over the bottom (14) of the cardboard plate opening up until 
their movement is prevented by some round profiles (10, 12), respectively, 
determining the bevelled edge of each wing (6, 7) at this moment, the 
folded edge (15) of the walls (16) of the box located underneath. 
This folding can be done thanks to the pressure exerted on the former, by 
the support, since it is transmitted to the box. 
The folding will, likewise, be done upon the other walls of the box, until 
they come up against the plates (1, 2.) 
Once the side walls (16) of the entire box are formed as shown in FIGS. 3 
and 4, the former rises and the wings (6, 7) pivot by gravity until they 
touch the rounded profiles (11, 13). respectively, located underneath, 
with the advantage that if the box has horizontal bridges (17, 18), the 
former will be able to come out since the wings (6, 7) have withdrawn and 
they will not touch the wings. 
Whether the wings (6 7) are rectangular or "U"-shaped they act in the same 
manner; and if the former has a bridge (3) or a sheet (4) like an interior 
top surface, between the plates (1, 2) it is due to the diversity of 
shapes that these wings or plates can have in order to adapt to the 
different types of boxes to be folded. 
Likewise, the wings as well as the plates can be interchangeable, whereby a 
large number of types of boxes can be covered with a small number of wings 
and plates.