PLASTIC FOLDER FOR SHEETS OF PAPER

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: PLASTIC FOLDER FOR SHEETS OF PAPER FIELD OF INVENTION This invention relates to a folder mainly for the retention of rectangular sheets of paper of a certain size, consist- ing of at least one piece of plastic or other materials 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 covering foil, preferably the front side, have been joined. 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 card- board, 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 disadvan¬ tage, 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 shee . Therefore, special types of folders have been developed, the so-called quotation folders f 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. SUMMARY-AND OBJECTS OF THE INVENTION The folder according to this invention is characterized by 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 the front and with a minimum space between the areas measured along the back which is close to or pre¬ ferably smaller than the length of that edge of the con¬ tained sheets which is meant to face the back of the fold.er. 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 approx one sheet margin's di¬ stance 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. A , even when made of various paper quali¬ ties, 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 with as one single sheet. As the minimum distance between the welded areas at the top edge of the folder and the area at the bot-tom 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 di ferent 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 mea¬ sures 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 firm¬ ness 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 be¬ tween 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 eτige 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 be¬ tween 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 diffi¬ culty, 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 there¬ fore 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 wel- ded 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 bac 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 fol¬ der, close to the back of the folder. Now the upper edge of the sheets are pressed slightly downwards, giving the sheets a wawy 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. ~~ ^ _ 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 elsatic foil or by taking various measures, which 5are mentioned later. Another inconvenience is that the folder is not able to retain the sheets quite so effectively as the known quo¬ tation 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, nor¬ mally 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 pla- stic 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 wel¬ dings. The plastic folder can, therefore, be made especial- ly functional and pleasnt 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 fol¬ ders 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 pro- duct, which can compare with the known types of quotation folders without being, as they are, made from PVC, a mate¬ rial 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 inven- tion, 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 mimiimim 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 retentio of the sheets. Fig. 2 shows an enlarged section from Fig. 1 of the section A-B of the joined area 10. In a) in the section 12 is seen a convex bulge 14 in the front side 3 and a corresponding concave bulge 15 in the back side 4 with the purpose of increasing the squeezing effect on the contained sheets 6. In b) in the section 12 are shown foldings l6 as an example of other types of bulges or treatments to improve the re¬ tention 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 bot¬ tom 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 draw¬ ing to be the same which will generally be the most expe¬ dient. 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 in¬ to 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 . Be¬ tween the back 2 and the weldings 18 there is a number of holes 19 ι 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 mar- gin'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, con¬ trary to the other designs shown, that the sheets 6 have holes 20. The change from the previous design is ' that the holes 1 of the folder are placed in such a way that they correspond to the.holes 20 in the sheets 6, but are expe¬ diently 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 fol¬ der 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. Figo 6 shows another simple method of increasing the ela¬ sticity 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 bot 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 in¬ creasing 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, whic 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 per orations, 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 to- wards the sheets 6, forming a funnel, whic 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 measuresVthe 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 tape¬ rings 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 limi¬ tations against the sheets, preferably the taperings 23, are situated as closely to the sheets as possible. The rea¬ son that it is these parts of the joined areas, which can be easily torn off, is due to the fact that the minimum in¬ terval 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 un¬ intended 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 surrounde 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 posi- tioned 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 re- move 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 2^ 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 mini¬ mum interval between these last two taperings can well be greater than the length of the edge 17j 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 older according to the invention. Other types of e.g. joined areas cuttings, per orations, 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 prin¬ ciples of the invention. The material for the folder can suitably be polypropylene foil, which is copy-proof, not dagerous to the environment, and stands up to being folded to form a back. Other mate- rials, such as polyethylene and sp cial 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 com¬ prises 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 inter¬ val 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: CLAIMS 1. Folder (l) mainly for the retention of rectangular sheets 2 of paper (6) of a certain size, consisting of at least one piece of plastic or other material, which has been folded or 4 joined together to a back (2) whereby is obtained a front side (3) and a back side (4), each having a front edge (7) > 6 a top edge (8), and a bottom edge (9) and where there is, at the top edge (8) at least one area (lθ), and at the bottom 8 edge (9) at least one area (ll) where the back side (4) and the covering foil, preferably the front side (2) have been 10 joined c h a r a c t e r i z e d by the whole joined area (lO) at the top edge (8) and the whole joined area (ll) at 12 the bottom edge (9) being placed in the section closer to the back (2) than to the front (7) and with a minimum space be- l4 tween the areas (lθ) and (ll) measured along the back (2), which is close to or preferably smaller than the length of l6 that edge (17) of the contained sheets (6) which is meant to face the back of the folder (2). 2. Folder (l) according to claim 1, c h a r a c t e r 2 i z e d by the horizontal distance from the back of the fol¬ der (2), or from a welding (l8) parallel to the back (2), to 4 farthest part of the joined areas (lθ) and (ll) being suit¬ ably the same and the size of a standard sheet margin or pre- 6 ferably less. 3» Folder (l) according to claim 1, c h a r a c t e r - 2 i z e d by the exisistence of sections (12) and (13), at at least one of the joined areas (lθ) and (ll) , with pre- 4 ferably corresponding concave or convex bulges (l4) and (15) or other forms of treatments or bulges, such as foldings (l6) 6 of the front side (3) and/or the back side (4) of the folder in order to improve the retention of the sheets (6) D 4. Folder (l) according to claim 1, c h a r a c t e r - 2 i z e d by the minimum distance between the joined areas (lO) and (ll), measured along the back (2), being" less than 4 equal to the length of the edge (l7) of the sheets (6) which is meant to bear against the back (2) in order that these sheets are firmly fixed between the joined areas (lO) and (11). 5. Folder (l) according to claim 1 and 4, c a r a c - t e r i z e d by cuts above the joined areas (lO) and/or below the joined area (ll) increase the flexibility between the areas (lO) and (ll). 6. Folder (l) according to claim 1 and 4, c h a r a c - t e r i z e d by the joined area (lO) and/or below the joined area (ll) or the space between these, having perfo- rations/cuts (22), holes (l9)» foldings (l6) or other mea¬ sures suitably in both the front side (3) and the back side (4) to increase the flexibility of the foil. 7. Folder (l) according to claim 1 and 4 , c h a r a c - t e r i z e d by the fact that the part of at least one of the joined areas (lθ) and (ll) which face the sheets (6) has taperings (23) pointing towards the sheets and preferably slanting towards the back forming a funnel. 8. Folder (l) according to claim 1 and 4 , c h a r a c - t e r i z e d by at least one of the joined areas (lθ) and (ll) being made up of two or more sections or having more than one tapering (23) against the sheets (6). 9. Folder (l) according to claim 1-and 4 , c h a r a c - t e r i z e d by perferations (22) or other forms of weak¬ enings of the material round at least one of the sections of at least one of the areas (lθ) and (ll) so that at least one part (24) of the joined area (ll) can be removed, whereby the minimum distance between the joined areas (lO) and (ll) can be gradually increased. 10. Folder (l) according to claim 1 and 4 , c h a r a c - t e r i z e d by the taperings (23), situated in the areas (24) and (25) which are meant for removal, being placed clo- ser to the sheets (6) than the other taperings (23) in the areas (lθ) and (ll), and chiefly also close to the back (2) of the folder.

Inventors: GRAM OLE, GRAM, OLE
Applicants: GRAM OLE AS, OLE GRAM A/S
Application year: 1989
Main classification: B42F7
IPC codes: B42F7