EP0422133B1

EP0422133B1 - Plastic folder for sheets of paper

Info

Publication number: EP0422133B1
Application number: EP89911786A
Authority: EP
Inventors: Ole Gram
Original assignee: OLE GRAM AS
Current assignee: OLE GRAM AS
Priority date: 1988-10-17
Filing date: 1989-10-17
Publication date: 1994-06-29
Anticipated expiration: 2009-10-17
Also published as: DK577188A; JPH03503869A; WO1990004524A1; EP0422133A1; DE68916544T2; AU4422589A; DE68916544D1; ATE107897T1; DK577188D0

Abstract

The invention refers to a folder (1), intended for sheets (6) of a specific size. The folder (1) is made of a foil of plastic or other material. The foil is folded to form a spine (2), a front side (3) and a back side (4). A joint (10) is provided at the top edge (8) of the folder (1) to join together the front (3) and back (4) side. A corresponding joint (11) is provided at the bottom edge (9). Both joints (10, 11) are placed at a distance of preferably a little less than a sheet margin from the spine (2) of the folder (1), and at a minimum distance, in the spine direction, which is close to and preferably a little shorter than the length (17) of the retained sheets (6). If the distance is shorter, then the joined areas (10, 11) at the top (8) and bottom (9) will press downwards and upwards respectively against the top and bottom edges of the sheets (6), by which arrangement a sufficient retention of the sheets (6) is achieved. Insertion and removal of sheets (6) can be quick and easy and they can be turned over like leaves in a book.

Description

FIELD OF INVENTION

This invention relates to a folder for the retention of at least one rectangular sheet of paper of a certain size, said folder being able to retain sheets of standard format such as A4 consisting of at least one piece of plastic, which has been folded or joined together to a back whereby is obtained a front side and a back side, each having a front edge, a top edge and a bottom edge, and where there is at the top edge at least one area, and at the bottom edge at least one area, where the back side and the front side have been joined and that the whole joined area at the top edge and the whole joined area at the bottom edge being placed in the section closer to the back than to the front edge.

DISCUSSION OF PRIOR ART

The simplest known form of a folder for sheets of paper and the like consists of a simple piece of plastic foil or cardboard, which has been folded to make a back, a front side and a back side. The disadvantage of such a folder is that the contained sheets slip out too easily when the folder is moved or dropped.
To improve the retention of the sheets the folder can be welded along the bottom side making a so-called dossier. Here the sheets will, however, still be able to slide up and down. To improve the retention of the sheets the folder can, in addition to the bottom side, also be welded along the front side or along the top side, making a so-called plastic pocket.
All folders with welded edges have, however, the disadvantage, when they contain more than a single sheet of paper, that it is not possible to leaf through the sheets, just as you leaf through a book. You must, therefor, first take the sheets out of the folder if you want to see more than the front side of the top sheet and the back side of the bottom sheet.
Therefore, special types of folders have been developed, the so-called quotation folders, in order to be able to leaf through the sheets, while they are being retained in the folder. One well-known type has in its back a locking device with a paper binder for sheets of paper with holes. Another type has a squeezer inserted in the back for the retention of the sheets, which do thus not need holes. Both types of quotation folders are, however, rather difficult to use and expensive to manufacture.
There are also known plastic folders where the front side and the back side are joined together at the top edge and at the bottom edge. But the purpose of these joinings are to prevent the contained sheets from falling downwards or upwards, not to squeeze the sheets so much together that they are hereby retained. In German Patent, DE 1116630 the horizontal length of both the top welding and the bottom welding are large and prohibitive for placing sheets between them, unless the distance between them is a lot greater than the length of the edge of the contained sheets. In Swiss Patent, CH 177598 the distance between the joined area at the top and the joined area at the bottom is considerably greater than the length of the edge of the contained sheets, so that no squeezing effect from the folder can be obtained.

SUMMARY AND OBJECTS OF THE INVENTION

The folder according to this invention is characterized by the minimum distance between the joined area at the top and the joined area at the bottom, measured along the back, being equal to or a little less than the length of the edge of said at least one sheet of paper, which is meant to bear against the back in order that said at least one sheet of paper is firmly fixed between the joined area at the top and the joined area at the bottom.
As the folder has the back side joined to the front side, or possibly to an intermediate strip of foil, at the top and the bottom edge only at approximately one sheet margin's distance from the back, it is possible to leaf through the retained sheets as in a book. The retention of the sheets is based upon the fact that sheets of paper of a standard size like e.g. A4, even when made of various paper qualities, have the same size within fractions of a millimeter, and that more sheets of the same size have, when they are properly held together, the same length and width as one single sheet. As the minimum distance between the welded areas at the top edge of the folder and the area at the bottom edge is very close to the length of the retained sheets facing the back of the folder, the folder will thus be able to squeeze the sheets so much together that they are retained. This squeezing is made in two fundamentally different ways:
If the minimum distance along the back between the welded areas at the top and at the bottom is only slightly longer than the corresponding length of the inserted sheets, there will be a slightly squeezing effect on the sheets by the front and the back side of the folder, or in certain cases from the back side and a strip of foil joined to it. This effect can be improved quite a lot by making various measures in the areas between and close to the welded areas. The foil can thus in these areas, suitably in both the front and the back side, be provided with preferably mutually corresponding convex and concave bulges, whereby the folder has an extra squeezing effect on the sheets, like a sort of paper clip. This presupposes, however, a certain firmness and thus a certain thickness of the foil. Further or instead of this the inside of the folder may in these areas have grooves or various forms of bulges or treatments which increase the retention of the sheets.
Another type of squeezing of the sheets is obtained by a specially suitable design of the folder according to the invention, where the minimum distance along the back between the welded areas at the top and at the bottom is less than or equal to the corresponding length of the contained sheets. Contrary to the above mentioned and to hitherto known folders and quotation folders, where the top side and the bottom side of the sheets are being pressed together, the retention is obtained in this case by the top edge of the contained sheets being pressed against their bottom edge and vice versa. The compressing force is thus directed parallel to the surface of the sheets and not, as in the hitherto known solutions, at right angles to the surface of the sheets. Therefore, not much force is needed, because it acts on a very small area, and this is why the pressure, being force per area unit, will be sufficient enough to retain the sheets suitably well in the folder.
Hitherto known folders with weldings in both top edge and bottom edge, plastic pockets, have a minimum distance between the weldings which is somewhat larger than the length of the sheets of paper meant to be inserted into the folder, as the sheets cannot otherwise, or only with great difficulty, be inserted into or taken out of the plastic pocket. The fact that the folder according to the invention is able to have a minimum distance between the welded areas, which is equal to or even less than the sheet length, may therefore seem surprising. This is however due to the fact that not only the front edge of the folder, but also the greater part of the top edge and the bottom edge have not been welded together. The folder can thus be opened almost all the way towards its back before the sheets are inserted into it, as the welded areas are placed rather closely to the back and are of a limited size.
The insertion of the sheets in the folder can therefore simply be done by first placing the bottom edge of the gathered sheets on the lower welded area of the opened folder, close to the back of the folder. Now the upper edge of the sheets are pressed slightly downwards, giving the sheets a wavy profile and allowing their top edge to be placed under the welded area of the top edge and close to the back of the opened folder. When the sheets are released, they will straighten out completely in the now closed and level folder and lie flat and firmly fixed between the two welded areas, correctly aligned in the folder by its back. It is, however, a condition that the minimum distance between the areas at the top and at the bottom is only slightly shorter than the length of the contained sheets, as these will not otherwise straighten out cmpletely.
Especially this last version of the folder according to the invention has, therefore, the disadvantage that the minimum distance between the top and the bottom welded area must be within a very narrow interval. If this interval becomes only a little too big, the retention is reduced inadmissibly. If, however, the interval becomes too small, the inserted sheets will not lie completely level in the folder. This drawback can, however, be conteracted by the folder being made from a specially thin and elastic foil or by taking various measures, which are mentioned later.
Another inconvenience is that the folder is not able to retain the sheets quite so effectively as the known quotation folders. In most cases the folder according to the invention will, however, have a sufficiently good retention capacity. Only if one or very few sheets are inserted after a folder has contained many sheets, it may happen that the folder has been enlarged so much that the retention becomes too poor. After a certain pause, dependent upon the type and thickness of the foil, the folder will, however, normally have regained its former qualities.
The advantages of the folder according to the invention are in particular: The folder can be manufactured quickly and cheaply on existing machinery and from ordinarily used plastic foils, such as polypropylene and polyethylene. It does not need the welding on of any kind of securing mechanismes, but only weldings of a slightly different and even smaller pattern than used on the hitherto known folders with weldings. The plastic folder can, therefore, be made especially functional and pleasant to look at, just as it will not take up more room than existing folders and be just as easy to pack and ship. Contrary to the existing quotation folders this folder can be manufactured so cheaply by thin foil that it may even compete with staplers and paper clips, which opens up new possible applications for this type of plastic folder, and also because it is quick and easy to use.
The folder according to this invention can also, if wanted, be made from more types of foil into a prestige like product, which can compare with the known types of quotation folders without being, as they are, made from PVC, a material to be avoided because of environmental considerations. Further, the folder can be used for a simple form of quick binding of, e.g. reports, whereby it can replace spiral backs, etc..

BRIEF DESCRIPTION OF THE DRAWING

Additional advantages of different designs of the folder according to this invention, as well as special details of the execution will appear from the drawing, where

Fig. 1 shows a design of the folder according to the invention, where the minimum space between the joined areas is a little bigger than the sheet length,
Fig. 2 two different, enlarged sections A-B of same,
Fig. 3 a design of the folder according to the invention, where the mimimum space between the joined areas is smaller than the sheet length,
Fig. 4 a similar design meant for insertion in a letter file,
Fig. 5 an alternative design of same,
Fig. 6 a design with cuttings at the joined areas,
Fig. 7 a design with cuttings and perforations at the joined areas, and
Fig. 8 a design with a different type of joined areas.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Fig. 1 shows a folder 1 consisting of a piece of plastic foil, which has been folded or welded to form a back 2, which connects a front side 3 with a back side 4, which can be seen through an incision 5. The folder contains one or more sheets 6. Both the front side 3 of the folder as well as its back side 4 have a front edge 7, a top edge 8 and a bottom edge 9, which on the drawing have been shown merging At the top edge 8 there is a joined area 10 of the front side 3 and the back side 4, and at the bottom edge 9 there is a corresponding joined area 11. At each of the joined areas 10 and 11 there is a section, 12 and 13 respectively, where there may be various measures to improve the retention of the sheets.
Fig. 2 shows an enlarged section from Fig. 1 of the section A-B of the joined area 10 at the top. In part a) in the section 12 there is a bulge 14 in the front side 3 of the folder and a corresponding bulge 15 in the back side 4, with the purpose of forming a supplementary force for increasing the squeezing effect on the contained sheets 6.
In b) in the section 12 are shown foldings 16 as an example of other types of bulges or treatments to improve the retention of the sheets 6.
Fig. 3 shows a specially appropriate design according to the invention, where the smallest interval along the back 2 between the joined areas 10 at the top and 11 at the bottom is smaller than the edge 17 of the sheets 6 which is meant to bear against the back 2. The joined areas 10 and 11 are placed at a sheet margin's distance from the back 2. By this is understood that the distance should not be much greater than a normal sheet margin, as one would then not be able to read everything on the sheet below, when one leafs through the sheets 6. On the other hand, the distance must not be too small, as the sheets can then fall out of the folder 1 too easily, when being handled. The top and the bottom distances from the back 2 are shown on the drawing to be the same which will generally be the most expedient. The execution of the joined areas 10 and 11 are also shown to be the same, which does not necessarily have to be the case either.
Fig. 4 shows a design of the folder meant for insertion into a paper file. Compared to the folder shown on Fig. 3 this is a little wider, and there is also, parallel to the back 2, a row of weldings 18 up against the sheets 6. Between the back 2 and the weldings 18 there is a number of holes 19, in this case two, in order to place the folder in the paper file. Regarding the distance from the joined areas 10 and 11 to the weldings 18 this should be a sheet margin's distance corresponding to the distance to the back 2 as mentioned in Fig. 3.
Fig. 5 shows an alternative design of the folder meant for insertion into paper files. However, this presupposes, contrary to the other designs shown, that the sheets 6 have holes 20. The change from the previous design is that the holes 19 of the folder are placed in such a way that they correspond to the holes 20 in the sheets 6, but are expediently a little larger than these to be able to take into account the possible deviations in the placing of the sheets in the folder. These deviations are, however, in practice moderate as the placing of the sheets in the folder according to the invention is far more precise than in a normal folder. A further effect of the holes 19 is that they provide an increased flexibility of the material of the folder between the joined areas 10 and 11.
Fig. 6 shows another simple method of increasing the elasticity of the retention of the sheets, so that they are level even though the interval between the areas 10 and 11 is somewhat smaller than the length of the edge 17 of the sheets 6. This is achieved by making cuts 21 above the joined area 10 and below the joined area 11, preferably in both the front and the back sides. These removals of a small piece of material have the effect that the interval between the areas 10 and 11 can more easily be made to vary a little extra. The cuts also have the visual effect that they indicate the location of the retention areas of the folder, the joined areas 10 and 11.
Fig. 7 shows an alternative or supplementary method of increasing the flexibility of the folder 1. At the joined areas 10 and 11 are shown perforations 22 preferably in both the front side 3 and the back side 4, which makes it possible for the joined areas 10 and 11 to give a little, upwards and downwards respectively. The cuts 22 can also be made as perforations, which can be opened according to need. These perforations can also be designed differently, e.g. as the holes 19 in Fig. 5. Instead of cuts these areas may have foldings corresponding to the ones shown in Fig. 2 b) to further increase the elasticity.
Fig. 8 shows a folder according to the invention, where the joined areas 10 and 11 each have taperings 23 slanting towards the sheets 6, forming a funnel, which have the effect that the contact area between the joined areas and the sheet is reduced to a very small area, whereby a greater pressure is obtained from the same squeezing effect made by the folder, force per unit area, being the pressure which is decisive of the retention. The taperings 23 have the further effect that the edges of the sheets 6 can more easily be deformed a little in those places where the joined areas touch the sheets, which has the effect, apart from an even better retention, that the sheets can more easily be made to lie level in the folder. Further, Fig. 8 shows quite a different type of measures to obtain the last mentioned, viz. a possibility to vary, step by step, the minimum interval between the joined areas 10 and 11, when those are, as shown here, devided into several parts, or each has more taperings 23. This can be done suitably by making perforations 22 in both the front side 3 and the back side 4, or other types of weakenings of the foil round the one or those parts of the joined areas 10 and 11, whose outermost limitations against the sheets, preferably the taperings 23, are situated as closely to the sheets as possible. The reason that it is these parts of the joined areas, which can be easily torn off, is due to the fact that the minimum interval between the joined areas 10 and 11 can thus be made greater, while the opposite is not possible. The placing of those parts of the joined areas, which is not to be torn off, can preferably be farthest away from the back 2, as the folder is thus protected in the best way against unintended tearing of the perforations and can thus also be opened to the same distance from the back, even after one or more tearing offs. In the case shown in Fig. 8, where both the joined areas 10 and 11 are devided into two parts, where the ones pointing towards the back are surrounded by perforations 22, three possible steps can be obtained: If e.g. the number of sheets is especially large or the length of the edge 17 is in the upper bracket of the standard size, the minimum interval between the two on the left side positioned taperings 23 may turn out to be too small, so that the sheets will not be level in the folder. One can now take out e.g. the uppermost, against the left positioned joined area by tearing off the perforation 22 and thus remove the limited area 24. This will increase the minimum interval between the top and the bottom joined areas by one step, as the minimum interval will now be between the top right and the bottom left taperings. If this increase is sufficient, the area 25 with the joined area and tapering towards the left side can also be removed by means of the bottom perforation 22, whereby the minimum interval between the top and the bottom joined areas is increased by another step and is now positioned between the two towards the right positioned taperings 23. It should be noted that the minimum interval between these last two taperings can well be greater than the length of the edge 17, so that a great number of sheets can be level in the folder and also be firmly fixed between the two joined areas 10 and 11. The folder according to the invention should thus, in this simple way, be able to cover a wide variation of sheet lengths and number of sheets of the standard size belonging to the folder, e.g. A4.
The drawing shows some characteristic examples of the folder according to the invention. Other types of e.g. joined areas, cuttings, perforations, and foldings may be possible and might have been shown, including more combinations of the various measures to improve the flexibility between the joined areas at the top and at the bottom. The examples shown should, however, be sufficient to show the basic principles of the invention.
The material for the folder can suitably be polypropylene foil, which is copy-proof, not dangerous to the environment, and stands up to being folded to form a back. Other materials, such as polyethylene and special foils, e.g. made from specially elastic copolymerisates or various laminated foils, may also be used. Polyvinyl chloride, PVC, may also be used, but should be avoided out of consideration for the environment, and because PVC needs weldings in the back, as the foldings break rather easily.
The joining of the material can most suitably be made by using various types of welding, such as ultra-sound, high-frequency and pulse welding. But the invention also comprises other types of joinings, including fastenings with staplers, riveting, sewing, gluing, etc.. This permits the use of stiff materials for the folder, such as cardboard, as the necessary flexibility between the joined areas at the top and at the bottom can be achieved by gluing with a rubbery substance, which can give both elasticity and a good friction.
Nor is the folder according to the invention limited to contain only rectangular sheets of the given size. The sheets may quite well have other sizes, if only the interval between those parts of the sheets which are to be placed between the joined areas at the top and at the bottom is correct, or the sheet can be folded to fit. Sheets of a smaller size may be mixed between the sheets of standard size. But the folder according to the invention will, of course, as all other folders be most suitable for exactly the size of sheets, it is meant for. The invention also covers designs, where the back side and extra foil, placed on top of it, have been joined to retain the sheets. They are more complicated to manufacture and use, but have the advantage that the cover can be opened completely. The extra foil does not have to be the same as the one for the folder and may consist of more than one strip of a suitable with of up to about a sheet margin's distance from the back of the folder.

Claims

Folder (1) for the retention of at least one rectangular sheet of paper (6) of a certain size, said folder being able to retain sheets of standard format such as A4, consisting of at least one piece of plastic, which has been folded or joined together to a back (2) whereby is obtained a front side (3) and a back side (4), each having a front edge (7), a top edge (8) and a bottom edge (9), and where there is at the top edge (8) at least one area (10), and at the bottom edge (9) at least one area (11), where the back side (4) and the front side (3) have been joined and that the whole joined area (10) at the top edge (8) and the whole joined area (11) at the bottom edge (9) being placed in the section closer to the back (2) than to the front edge (7), characterized by the minimum distance between the joined area (10) at the top and the joined area (11) at the bottom, measured along the back (2), being equal to or a little less than the length of the edge (17) of said at least one sheet (6) of paper, which is meant to bear against the back (2) in order that said at least one sheet of paper is firmly fixed between the joined area (10) at the top and the joined area (11) at the bottom.
Folder (1) according to claim 1, characterized by the horizontal distance from the back of the folder (2), or from a welding (18) parallel to the back (2), to the farthest part of the joined area (10) at the top and the joined area (11) at the bottom being suitably the same as or less than the normal margin size of a sheet (6) of paper of a for the folder (1) corresponding format.
Folder (1) according to claim 1 , characterized by the existence of sections (12, 13), at at least one of the joined areas (10, 11), with preferably corresponding concave or convex bulges (14, 15), or other forms of treatments or bulges, such as foldings (16) of the front side (3) and/or the back side (4) of the folder in order to improve the retention of the sheets (6).
Folder (1) according to claim 1 , characterized by that the joined areas (10, 11) have a short direct contact line with the contained sheets (6), preferably by being formed as a curve against the sheets, in order that these sheets can be easily placed and firmly fixed between the joined areas (10, 11).
Folder (1) according to claim 1 and 4, characterized by cuts (21) in the top edge (8) above the joined area (10) and/or below the joined area (11) in the bottom edge (9) to increase the flexibility between the joined areas (10, 11).
Folder (1) according to claim 1 and 4, characterized by the fact that above the joined area (10) at the top and/or below the joined area (11) at the bottom, or the space between these, having perforations/cuts (22), holes (19), foldings (16) or the like suitably in both the front side (3) and the back side (4) to increase the flexibility of the foil and thereby the retention capacity of the folder (1).
Folder (1) according to claim 1 and 4 , characterized by the fact that the part of at least one of the joined areas (10, 11) which face the sheets (6) has taperings (23) pointing towards the sheets and preferably slanting towards the back forming a funnel.
Folder (1) according to claim 1 and 4 , characterized by at least one of the joined areas (10, 11) being made up of two or more sections or having more than one tapering (23) against the sheets (6).
Folder (1) according to claim 1 and 4, characterized by perforations (22) or other forms of weakenings of the material round at least one of the sections (24) of the here in two separate places joined area (10) at the top and the in two separate places joined area (11) at the bottom, so that at least one of the sections (24) can be removed, thus increasing the distance between the joined areas (10) and (11), as the distance between the innermost parts of the joined area (10) at the top and the joined area (11) at the bottom are shorter than the distance between the respective outermost parts of the joined areas (10) and (11).