File folder with connecting side pieces

Abstract: File folder, comprising a first sheet (2) made of a rigid material having a first edge, a second edge and two side edges (14); a second sheet (3) made of a rigid material having a first edge, a second edge and two side edges (15); a back section (4) flexibly connecting said first sheet (2) and said second sheet (3) to each other at said first edges; an inwardly directed flap (5) made of a rigid material connected to at least one of said sheets (2-3) at the second edge thereof; and connecting side pieces (7) which connect said flap (5) to said at least one of said sheets (2-3) at the side edges (14-15) thereof, such that said flap (5) is kept spaced at a distance from said at least one of said sheets (2-3), said connecting side pieces (7) being attached to said flap (5) and said at least one of said sheets (2-3) by mechanical connections (17-18-19); and locking elements which can be inserted between the flap (5) and the said at least one of said sheets (2-3) at said side edges (14-15), said elements preventing the mechanical connections (17-18-19) from becoming loose and consisting of discrete elements which are separate from said connecting side pieces (7).

Description: The present invention relates to a file folder, more particularly to a file folder which may be used to contain bundles of loose documents or periodicals and the like. More paticularly, it concerns a file folder which has an inwardly directed flap and connecting side pieces which keep the flap spaced at a distance from the sheet to which the flap is attached. With the known types or file folders, the connecting side pieces are glued to the edges of the respective sheet to which the flap is attached. The known embodiments have a number of drawbacks. For instance, the assembly must be done in the factory and the file folder occupies more space in its finished shape. This is disadvantageous for storage in the factory, as well as with the user, and for transport. Moreover, each desired thickness requires another file folder, which requires a stock composed of file folders of different thicknesses. The quality of the connection between the connecting side pieces and the edges is difficult to control for said known embodiments because the connections are made using glue (adhesive). Quality control is only possible in a destructive way, whereby the file folder cannot be used anymore. A solution to the above problems is known from the American patent No. 5.931.373 of present applicant. According to this solution, the connecting pieces are attached to the concerned sheet and the flap by means of mechanical connections. In this way, such file folder offers the advantage that it may be assembled at the moment of its use. As a result, the volume of the file folders which must be maintained in inventory or storage is reduced considerably. With one file folder which must be assembled, connecting side pieces of different thicknesses (widths) may be used. Therefore, only one type of file folder needs to be kept in inventory instead of two or three types, as was previously the case. The user himself may now determine which type of file folder he assembles. In other words, he himself may choose the desired folder thickness. From the American patent No. 5.931.373, it is also known that locking means, in the form of spacers, may be provided which can be inserted between the sheet and the flap, thereby avoiding that the mechanical connections can become loose. According to this American patent, these locking means are formed by parts which are made in one piece with the connecting pieces and which are hingably connected to these connecting pieces by means of a hinge which is formed by a weakening in the material. In this way, after having assembled the file folder and the connecting pieces, said parts can be turned inwardly in order to be inserted between the sheet and the flap. Notwithstanding the fact that said locking means are very adequate, in case of an irregular use of the file folder, it may happen that the locking means become loose, more particularly that said part is hinged back under the influence of the elasticity in the material of the hinge. The present invention aims at an improvement providing in a solution to the above-mentioned problem. To this end the invention relates to a file folder, comprising a first sheet made of a rigid material having a first edge, a second edge and two side edges; a second sheet made of a rigid material having a first edge, a second edge and two side edges; a back section flexibly connecting said first sheet and said second sheet to each other at said first edges; an inwardly directed flap made of a rigid material connected to at least one of said sheets at the second edge thereof; and connecting side pieces which connect said flap to said at least one of said sheets at the side edges thereof, such that said flap is kept spaced at a distance from said at least one of said sheets, said connecting side pieces being attached to said flap and said at least one of said sheets by mechanical connections; and locking elements inserted between the flap and the said at least one of said sheets at said side edges, said locking elements preventing the mechanical connections from becoming loose, characterized in that the locking elements comprise discrete elements which are separate from said connecting side pieces. Due to the fact that, according to the present invention, the locking elements consist of separate elements, in other words elements which are not connected permanently to the connecting side pieces, there is no longer a hinge between the locking element and the corresponding connecting side piece, resulting in that forces which may be exerted by such hinge, urging such locking element in a dislocked condition, are completely excluded. Preferably, the second sheet is formed by a rear sheet, the flap is connected to this rear sheet by means of the connecting side pieces, and the first sheet is formed by a front sheet, this front sheet being free of such flap. In a preferred embodiment, the locking elements consist of separate elements which can simply be clamped between the flap and the concerned sheet. In the most preferred embodiment, the mechanical connections comprise mortise and tenon joints. However, other connections, such as snap connections, are not excluded. In a preferred embodiment, the mortise and tenon joints will not only be provided between the connecting side pieces and the sheet and the flap, but likewise between the connecting side pieces and the flexible link between the flap and the sheet. In order to better show the characteristics of the invention, a preferred embodiment according to the present invention is described hereafter, as an example without any restrictive character whatsoever, reference being made to the accompanying drawings, in which: figure 1 represents a perspective view of a file folder according to the invention; figure 2 represents the file folder of figure 1 in exploded view; figure 3 represents a top view of the unfolded folder shown in figure 1 without connecting side pieces; figure 4 is a perspective view of a connecting side piece shown in figure 2; figure 5 is a cross-section taken along line V-V in figure 1; figure 6 is a vertical sectional view taken along line VI-VI in figure 5, on a larger scale. The file folder 1 according to the invention comprises, as represented in figures 1 and 2, a front sheet 2 and a rear sheet 3 made of a rigid material which are connected to each other by a flexible or flexibly attached back section 4. In this case, rear sheet 3 is elongated by a flap 5 which is folded back and which, by means of a fold panel 6, is connected to said sheet 3. Flap 5 is kept spaced at a distance from sheet 3 by two connecting side pieces 7. Front sheet 2, rear sheet 3, back section 4 and flap 5 are preferably manufactured from a type of thick cardboard and may be provided with a covering, such as a smooth foil which is bonded to the cardboard. As represented in figure 3, a number of fold lines 8 may be provided at the spot of back section 4. Similarly, fold lines 9 may be provided at the fold panel 6. These fold lines 8-9, for example may be made by thinning of the material, such as indentations. As represented in figures 2 and 4, each side piece 7 comprises a single piece preferably made of synthetic material mainly formed of an elongated wall 10 having inwardly directed edges 11-12-13 located at three sides thereof. The inwardly directed edges form supports for the side edges 14-15-16 of rear sheet 3, flap 5 and fold panel 6. As represented in figures 5 and 6, the connecting side pieces 7 are attached to the file folder 1 by mechanical connections, more particularly a plurality of mortise and tenon joints. In this case, three connections for each connecting piece 7, namely 17-18-19, are used. As represented in the example, the mortise and tenon joints are not only provided between connecting side pieces 7 and rear sheet 3 and flap 5, but likewise between connecting side pieces 7 and fold panel 6. More particularly, three pairs of mortise and tenon joints are provided for each connecting side piece 7, two pairs of mortise and tenon joints 17-18 at free extremities of inwardly directed edges 11 and 12 and a third pair of mortise and tenon joint 19 at inwardly directed edge 13, respectively. To realize the connections 17-18-19, more particularly the mortise and tenon joints, a plurality of mortises 20-21-22 are applied on the proper file folder, as represented in figures 2 and 3. Corresponding tenons 23-24-25 are applied on connecting side pieces 7 such that they are integrally formed with connecting side pieces 7. Tenons 23-24-25 are located at an inner side of the inwardly directed edges 11-12-13, so as to extend perpendicular inwardly into engagement with the adjacent mortises 20-21-22. Tenons 23-24-25 are preferably of a circular shape and are of a length which corresponds with the thickness of the material from which the actual file folder is made or as shown in figure 6 may be a little bit longer. The diameter of tenons 23-24-25 preferably corresponds with the diameter of mortises 20-21-22 or is even a little greater such that during the assembly a friction locking effect is obtained. As is made clear in figures 2, 5 and 6, file folder 1 is provided with locking elements 26 which prevent the mechanical coupling and more particularly the mortise and tenon joints 17-18-19 from becoming loose due to motion of rear sheet 3 and flap 5 towards each other. These locking elements 26 are of such dimensions that they can be inserted between the respective sheet, in this case rear sheet 3, and flap 5 such that the rear sheet 3 and flap 5 cannot move towards each other anymore. Consequently, they cannot become loose from tenons 23-24-25. Because mortise and tenon joints 17-18-19 cannot be loosened anymore, the result is obtained that connecting side pieces 7 cannot slide away laterally with respect to the actual file folder. The improvement of the present invention consists in the fact that the locking elements 26 are completely separate elements, in other words also separate from the connecting side pieces 7. As mentioned before and as shown in figure 6, tenons 23 and 24 may possibly be made longer than the thickness of the material of file folder 1. As a result, the locking elements 26 may be clamped more or less behind said tenons 23-24. Figure 6 clearly shows the relationship between the rear sheet 3, the flap 5 as well as the mortise and tenon joints retaining the connecting side pieces 7 assembled with the rear sheet 3 and flap 5. Hereby it should be noted that the locking elements 26 preferably include a panel element 27 and inwardly extending edges 28 that, in the assembled position, overlies mortises 20-21 to prevent inward displacement of rear sheet 3 and flap 5 relative to connecting side pieces 7 and holds the rear sheet 3 and flap 5 in connection with the edges 11-12. Each locking element 26 may be made of a material similar to that of the side pieces 7 or any other appropriate relatively rigid material, such as rigid synthetic resin material suitable to perform the desired locking function for preventing inward movement of the rear sheet 3 and the flap 5. The inwardly extending edges 28 may be connected to the panel element 27 of a respective locking element 26 by a flexible elastic connection, obtained by forming the edges 28 in one piece with said panel element 27, so that the edges 28 may be bent inwardly slightly as illustrated in figure 6 when they are engaged between the opposite tenons 23 and 24. In this manner, the edges 28 provide in a resilient bias force (friction or snap connection) between the opposed tenons 23 and 24. It is clear that according to a variant, flap 5 may also be located adjacent front sheet 2. It is also not excluded to attach a flap 5 to front sheet 2 as well as to rear sheet 3 by connecting side pieces 7. The assembly of file folder 1 may be deducted simply from the figures. In the first instance, flap 5 must be brought completely inwardly until abutting rear sheet 3. Subsequently, connecting side pieces 7 are applied such that the connection 19, in other words the corresponding mortise and tenon joint is formed. Then, by pushing flap 5 and rear sheet 3 away from each other, connections 17 and 18 are formed. The file folder 1 may be locked then by locking elements 26. These locking elements 26 are installed just by inserting them between the rear sheet 3 and the flap 5 and pressing them into a position as shown in figure 6. In addition to the mechanical connections, a pair of inwardly projecting sheet edge support elements 29-30 adjacent and spaced slightly away from inwardly directed edges 11 and 12, may be provided about midway along the length of each connecting side piece 7 to support the side edges 14 and 15 of rear sheets 3 and flap 5 as shown in figure 5. When fully assembled, it will be fully evident that the sheet 3 and flap 5 are retained in separated relationship along their side edges and the connecting side pieces 7 can not be separated from the rear sheet 3, fold panel 6 and flap 5. It is clear that the tenons and mortises may show different shapes. Moreover, instead of tenons and mortises, the mechanical connections may also be of a different form. Furthermore, it is also clear that the locking elements 26 and/or the connecting side pieces 7 and/or the side edges 14-15 may be provided with any kind of means or elements providing in a clamping or locking effect to retain the locking elements 26 in their locked position. The present invention is in no way limited to the embodiments described above and represented in the drawings, but such a file folder may be realized in different shapes and dimensions, without departure from the scope of the invention, as defined by the following claims.

Claims: File folder, comprising a first sheet (2) made of a rigid material having a first edge, a second edge and two side edges (14); a second sheet (3) made of a rigid material having a first edge, a second edge and two side edges (15); a back section (4) flexibly connecting said first sheet (2) and said second sheet (3) to each other at said first edges; an inwardly directed flap (5) made of a rigid material connected to at least one of said sheets (2-3) at the second edge thereof; and connecting side pieces (7) which connect said flap (5) to said at least one of said sheets (2-3) at the side edges (14-15) thereof, such that said flap (5) is kept spaced at a distance from said at least one of said sheets (2-3), said connecting side pieces (7) being attached to said flap (5) and said at least one of said sheets (2-3) by mechanical connections (17-18-19); and locking elements which can be inserted between the flap (5) and the said at least one of said sheets (2-3) at said side edges (14-15), said elements preventing the mechanical connections (17-18-19) from becoming loose, characterized in that the locking elements (26) consist of discrete elements which are separate from said connecting side pieces (7). File folder according to claim 1, characterized in that the second sheet is formed by a rear sheet (3), the flap (5) is connected to this rear sheet (3) by means of the connecting side pieces (7), and the first sheet is formed by a front sheet (2), this front sheet (2) being free of such flap (5). File folder according to claim 1 or 2, characterized in that the mechanical connections (17-18-19) comprise mortise and tenon joints. File folder according to claim 3, characterized in that the mortise and tenon joints are formed by mortises (20-21-22) in the proper file and by tenons (23-24-25) provided at inwardly directed edges (11-12-13) formed at the connecting side pieces (7). File folder according to any of the preceding claims, characterized in that the locking elements (26) are elements spanning the distance between the flap (5) and the sheet (2-3) to which said flap (5) is connected and/or the distance between the corresponding mechanical connections (17-18). File folder according to claim 5, characterized in that said locking elements (26) fit between said flap (5) and the sheet (2-3) to which said flap (5) is connected and/or between the mechanical connections (17-18) in a clamping relationship. File folder according to any of the preceding claims, characterized in that the locking elements (26) each consists of a panel element (27), provided with inwardly directed edges (28). File folder according to claims 4, 6 and 7, characterized in that the locking elements (26) are co-operating with tenons (23-24) which are slightly longer than the thickness of the sheet (3) and flap (5); and that the inwardly directed edges (28) of the locking elements (26) co-operate with said tenons (23-24) in such a manner that these edges (28) are bent slightly inwardly so as to provide in a resilient biasing force. File folder according to any of the preceding claims, characterized in that the connecting side pieces (7) consist of a wall (10) with inwardly directed edges (11-12-13) and in that said connecting side pieces (7) are provided with additional inwardly projecting sheet edge support elements (29-30) adjacent and spaced away from the inwardly directed edges (11-12), preferably provided about midway along the length of each connecting side piece (7).

Inventors: PELEMAN GUIDO, PELEMAN, GUIDO
Applicants: UNIBIND CYPRUS LTD, UNIBIND (CYPRUS) LIMITED
Application year: 2000
Main classification: B42F7
IPC codes: B42F7