SUSPENDED FILES

Abstract: A suspended file folder, for hanging on a frame in filing cabinets, desk drawers, file boxes, etc., is made essentially entirely from thermoplastic material, preferably a polyolefin polymer. A thermoplastic sheet (2) is folded along at least one and preferably two medial lines (3), to define a folder (4). Two separate thermoplastic support bars (7) are permanently fused one to each wall of the folder along the upper edges thereof to provide the required degree of strength and rigidity. The support bars have integral suspension portions (5) extending laterally from upper side edges of the folder, and have notches (6) therein to accommodate the suspension rails. The folder itself may have suspension portions also extending laterally from upper side edges of the main body of the folder, with notches matching and aligned with the notches in the support bars. The support bars preferably are provided with ribs (8) to enhance torsional and lateral rigidity and strength. Preferably, there are two such ribs or flanged portions, to provide adequate strength in order to resist bending, minimize deflection, and provide adequate load bearing capacity, all with sustained loading at various temperatures.

Description: SUSPENDED FILES TECHNICAL FIELD This invention relates to suspended file folders. BACKGROUND ART Suspended file folders are well known. The most common types are formed from a folded cardboard folder that is attached at its upper edges to metal support bars. The support bars project from either side of the folder to form hooks engageable with the suspension rails of a filing drawer. While such folders have achieved considerable commercial success, they have a variety of disadvantages or weaknesses, including some or all of the following: a. The support bars tend to be susceptible to being permanently bent or otherwise misshapen. Bent or misshapen bars alter the distance between the end hooks, potentially causing the file folders to fall away from the suspension rail. The bars typically are of metal of a thickness that causes them to bend easily and permanently when loaded with weight from files. b. The metal bars glide poorly on the metal suspension rails. Thus in some versions, separate plastic inserts attached to the metal bars are employed. c. The folders are subject to frequent crumpling or ripping, particularly at the medial fold which must bear both weight and impact from inserted files or papers, and also along the side edges. d. At the top of the folder, both in designs where the cardboard has been folded over the support bars and attached to itself, and in designs where the metal bar and the cardboard are glued or otherwise fastened to each other, the cardboard tends to detach as a result of general wear, poor quality glue, insufficient glue, or poor manufacturing techniques. e. Similarly, the metal bars tend to rip through the cardboard at the top of the folder, due to handling which cause the edges of the metal bar to cut through the cardboard. f. Recycling of the folders is inefficient, since it requires separating the cardboard portion from the metal portion. The presence of adhesives may make recycling more difficult. In practice, the folders are therefore not often recycled, and instead they are discarded into the waste stream, which is obviously undesirable. g. Manufacture of the folders is not as efficient as it would be if the step of securing the folder to the support bar could be avoided. Not all suspended file folder have all of the above problems, and indeed some designs have attempted to address some or all of these problems. However, they are still not sufficiently durable or otherwise close to ideal, and there remains a need for improvement such as that provided by the present invention. DISCLOSURE OF INVENTION In view of the above, it is an object of the invention to provide a suspended file folder which avoids or reduces as many as possible of the above- mentioned problems. The invention thus provides a suspended file folder assembly which is made essentially entirely from thermoplastic materials, preferably of the same family. The assembly uses a thermoplastic sheet folded along at least one medial line, such as a score line, to define a folder having opposing walls extending upwardly from the medial line(s). Two thermoplastic support bars are permanently fused one to each wall of the folder along or adjacent the upper edges thereof, to provide the required degree of strength and rigidity. The support bars have integral suspension portions extending laterally beyond side edges ofthe main body of the folder, having notches therein, such as generally U-shaped downwardly-opening notches, to accommodate the suspension rails of a typical suspended filing system. The structural profiles utilized in the support bars preferably include ribs or flanged portions substantially greater in thickness than the sheet of thermoplastic polymer, to form a structural channel shape to enhance torsional and lateral rigidity and strength in order to resist bending, minimize deflection, provide adequate bearing and shear capacity, under sustained loading at various temperatures. The folder may also have integral suspension portions extending laterally from upper side edges of the folder, matching and overlying the shape of the support bar, including having notches therein, corresponding to and aligned with the notches in the suspension portions of the support bars. Preferably, there are two of the medial lines at the bottom of the folder, so that the folder is somewhat U-shaped rather than V-shaped. Additional medial lines may be provided as well if desired, particularly to accommodate thicker files or more papers. The folders are preferably formed by fusing two substrates, i.e. the sheet together with the support bars. The folders are then completed by die-cutting to leave behind the folder shape including the suspension portions and notches. Preferably, the thermoplastic materials are polyolefin polymers, and more specifically polypropylene. Other families of thermoplastic materials can be used, such as oligablock copolymers like polystyrene or vinyl polymers like polyvinyl chloride (PVC). Fillers may be added to the sheet in order to reduce costs, or additives may be added to enhance desirable properties or create particular aesthetic appearances. The folders of the invention represent a significant improvement over the metal/folded cardboard folders that are currently used commercially. The folders of the invention, being formed from a thermoplastic material, are essentially not susceptible to such tearing. The thermoplastic support bars are not susceptible to permanent bending or to rusting which can discolour the body of the folder. The folders of the invention are also more resistant to wear, resistant to stains and humidity, and will keep their aesthetic qualities for a longer period of time. Because the folders of the invention may be made from one thermoplastic polymer family, they are conducive to recycling processes. BRIEF DESCRIPTION OF DRAWINGS The invention will be described with reference to the accompanying drawings of the preferred embodiments by way of example. In those drawings: Fig. 1 is a perspective view of the folder assembly; Fig. 2 is an end view of the folder assembly; Fig. 3 is a perspective view of the outside of the suspension portion of the folder; Fig. 4 is a perspective view of the inside of the suspension portion of the folder; Fig. 5 is a cross-section showing the preferred profile for the support bars; Fig. 6 is a cross-section showing one alternative profile for the support bars; Fig. 7 is an elevation view of the outside of the suspension portion of the folder; Fig. 8 is an elevation view of the inside of the suspension portion of the folder; Fig. 9 is a plan view of the folder assembly, laid open; Fig. 10 is a cross-section showing an index tab which is mountable on the folder assembly; Fig. 11 is a cross-section showing the index tab mounted on the folder assembly; Fig. 12 is a cross-section showing an alternative configuration of index tab, mounted on the folder assembly; Fig. 13 is a cross-section showing another alternative configuration of index tab, mounted on the folder assembly; and Figs. 14-18 are cross-sections of further alternative configurations of index tabs. BEST MODE FOR CARRYING OUT THE INVENTION Fig. 1 shows the file folder assembly 1, which is made essentially entirely from thermoplastic material. The assembly uses a thermoplastic sheet 2 folded along one or more medial lines, such as score line 3, to define a folder 4. Two thermoplastic support bars 7 are permanently fused one to each wall of the folder along or adjacent the upper edges thereof to provide the required degree of strength and rigidity. The support bars have notches therein, such as generally U-shaped downwardly-opening notches 6, to accommodate conventional suspension rails (not shown). The folder itself preferably but not necessarily has integral suspension portions 5 extending laterally from upper side edges, with notches matching and overlying the notches in the support bars. The support bars preferably are on the inside of the folder, but could be on the outside. They preferably are provided with ribs 8 substantially greater in thickness than the sheet of thermoplastic polymer, to enhance lateral and torsional rigidity and strength. The notches 6 preferably stop below the lowermost rib, to provide optimum load-bearing area on the widest possible portion of the profile and still maintain the greatest possible area of cross-section to provide adequate shear capacity. As seen best in Figs. 5 and 6, the lower portion ofthe support bars preferably is curved (Fig. 5) or straight-tapered (Fig. 6), to become flush with the sheet 2, to ensure that files or papers can be removed without catching on the support bars. The support bars can thus be viewed as a structural channel shape with a lower tail or tapered portion added. Preferably, there are two of the medial score lines 3 at the bottom of the folder, so that the folder is somewhat U-shaped rather than V-shaped, providing greater wear resistance by reducing the angle at each medial line. Additional medial lines may be provided as well if desired, particularly to accommodate thicker files or more papers, and of course their spacing may be varied. The folders are preferably formed by fusing the sheet together with the support bars. The folders are then completed by die-cutting to leave behind the folder shape shown in Fig. 9, i.e. including the suspension portions and notches. The material used to form the file folder is a thermoplastic polymer. It is preferred that the thermoplastic polymer be a melt-formable polymer, for ease of fabrication e.g. by melt extrusion of the polymer in a sheet. Excess polymer can also be recycled and re-extruded into a sheet. The polymer in the sheet used to form the folder should have substantial stiffness, but still be sufficiently flexible to permit insertion of files into the folder. Sufficient stiffness is required at the top of the folder i.e. in the area used to suspend the file folders, referred to herein as upper edges having integral projecting end portions. The polymer used to form the support bars, in particular, should have properties so as to provide sufficient stiffness over time, and strength as well as natural lubricity. The combination of proper polymer selection and adequate geometry of the support bars should result in substantially rigid load bearing capacity, but still have or allow for some flexibility. It is to be understood that this may be accomplished by selection of the thermoplastic material, but preferably is made from a blend of thermoplastic material with property enhancement fillers added to the matrix, which may be modified or enhanced with particular additives to achieve the desired material properties to meet or exceed the application required. The thermoplastic material is from the same family of thermoplastic polymers as that used for the sheet and is more conducive and amenable to recycling. In addition, it is preferable that the polymer sheet be capable of forming tough, tear-resistant folds. The folds need to have significant wear or notch resistance and strength for continued use of the folder. For thermoplastic materials, the thickness of the sheet used to form the body of the folder preferably should be at least 5 mils (0.005 inches), and preferably 10- 20 mils, 12-15 mils being the likely optimum. However, the thickness will depend on the particular thermoplastic polymer selected, and the strength and stiffness properties of that thermoplastic material, as well as the size of the folder being formed. The thermoplastic sheet used to form the folder will be preferably of uniform thickness. The sheet and support bars preferably are formed from or based on the same family of thermoplastic materials, to facilitate recycling. The thermoplastic polymer used to form the support bars preferably is made from a blend of thermoplastic materials with property enhancement fillers added to the matrix. Fillers could include materials such as talc, mica, glass, etc.. In view of the above, the preferred thermoplastic materials are polyolefin polymers such as polypropylene, for the folder 4, and reinforced polyolefin polymers such as polypropylene with a blend of property enhancement fillers added to the matrix, for the support bars 7. As seen in Figs. 10-13, indexing tabs 9 can be readily adapted to mount on the folder. The ribs 8 provide anchoring means for the indexing tabs, and a track for the tabs to slide along. The tabs can thus be attached and positioned easily. The indexing tab shown in Figs. 10 and 11 has an inside wall 10 and an outside wall 11 defining a U-shaped opening 12 between them. The inside wall has a bulbous end portion 13, which locates in the channel or track 14 between the ribs 7. The upper indexing portion of the tab has a face portion 15, and the embodiments shown in Figs. 11 and 12 have a label-carrying slot 16 defined behind the face portion. The Fig. 13 version is intended simply to have an adhesive label attached to the face portion, which Figs. 11 and 12 have transparent face portions to see a label carried in the slot. It will be appreciated that many variations on the invention will be obvious to those who are knowledgeable in the field. Such obvious variations are considered to be within the scope of the invention, whether or not expressly described above. For example, additional strength can be added by increasing the thickness of the base of the support bars and/or the height of the rib or flange portion, and/or by adding additional ribs or flanged portions. As another example, the support bar may be formed in or split into two parts, such that the two parts of the support bar sandwich or pinch the sheet, as shown in Fig. 14. Or, the sheet can be sandwiched or pinched in a support bar structure that is not completely split into two parts, as shown in Fig. 15. Advanced materials or engineered plastics can be used to permit the height of the ribs or flanged parts to be reduced. This can be used when cost or perception of materials permits it to be done economically. Should the sheet not be fused flush at the top edge with the support bar by accident, as shown in Fig. 16, by design in order to reduce costs (as shown in Figs. 17 and 18), or by design in order to accommodate ease of manufacturing, functionality will not be affected. The folders are preferably formed by extrusion, but can be formed by co- extrusion. The sheet and support bars can be permanently fused by lamination, by chemical bonding, fusion bonding, induction bonding, solvent bonding, thermocompression bonding, ultrasonic bonding or secondary bonding using a compatible resin or curing adhesive. As another variation, not illustrated, the sides of the folder could extend outwardly into alignment, or even beyond, the ends of the support bars, with recesses or cutout areas being provided near the top of the sides, i.e. just under the support bars. INDUSTRIAL APPLICABILITY The invention provides a sturdy suspended file folder. CLAIMS: 1. A file folder assembly for suspension in a filing unit with two spaced-apart suspension rails, said file folder assembly characterized by: a sheet (2) of thermoplastic polymer folded along at least one medial line (3) to define a folder (4) having opposing walls extending upwardly from said at least one medial line, each wall having an upper edge and side edges; and two separate thermoplastic polymer support bars (7), permanently fused one to each of said walls adjacent the upper edges thereof, at least a portion (8) of the cross-section of said support bars being substantially greater in thickness than said sheet of thermoplastic polymer, said support bars having integral suspension portions (5) extending laterally from portions of said side edges adjacent said upper edges of said folder, said suspension portions having notches (6) therein configured to accommodate said suspension rails to support said folder assembly. 2. A file folder assembly as recited in claim 1 , where said folder has integral suspension portions (5) extending laterally from said portions of said side edges, corresponding to and aligned with said suspension portions of said folders, said suspension portions of said folders having notches (6) corresponding to and aligned with said notches of said suspension portions of said support bars. 3. A file folder assembly as recited in claim 1 , in which said support bars are provided with at least one reinforcing structural portion (8) extending therealong and projecting slightly therefrom, to provide additional strength and torsional and lateral rigidity. 4. A file folder assembly as recited in claim 3, in which said at least one structural portion comprises spaced-apart upper and lower ribs (8) extending along said support bars and projecting slightly therefrom, to provide additional strength and torsional and lateral rigidity. 5. A file folder assembly as recited in claim 1 , in which said support bars have a lower edge that is tapered to become flush with the sheet, thereby allowing easier removal of files or papers without catching on the support bars. 6. A file folder assembly as recited in claim 1 , in which said folder and said support bars are composed essentially of a polyolefin polymer. 7. A file folder assembly as recited in claim 6, in which said support bars have property enhancement fillers incorporated therein. 8. A file folder assembly as recited in claim 1 , in which there are at least two said medial lines (3) spaced slightly apart from each other so as to provide a generally U-shaped folder. 9. A file folder assembly as recited in claim 4, further comprising at least one indexing tab (9) mountable on said folder, each said indexing tab having an inside wall (10) and an outside wall (11) defining a U-shaped opening (12) between them, said U- shaped opening being positionable over one of said support bars, and said inside wall having a bulbous end portion (13) configured to be self-locating in a track (14) defined by said upper and lower ribs (8), each said indexing tab further having an upper indexing portion (15) extending upwardly above said inside and outside walls and having a portion (16) for carrying labeling indicia. 10. A file folder assembly as recited in claim 1 , where: said folder has integral suspension portions (5) extending laterally from said side edges, corresponding to and aligned with said suspension portions (5) of said folders, said suspension portions of said folders having notches (6) corresponding to and aligned with said notches (6) of said suspension portions of said support bars; said support bars are provided with spaced-apart upper and lower ribs (8) extending along said support bars and projecting slightly therefrom, to provide additional strength and torsional and lateral rigidity; said support bars have a lower edge that is tapered to become flush with the sheet, thereby allowing easier removal of files or papers without catching on the support bars; and said folder and said support bars are composed essentially of a polyolefin polymer.

Claims: AMENDED CLAIMS [received by the International Bureau on 24 October 1997 (24.10.97); original claims 1,5 and 10 amended; new claim 11 added; remaining claims unchanged (3 pages)] 1. A file folder assembly for suspension in a filing unit with two spaced-apart suspension rails, said file folder assembly comprising a sheet (2) of thermoplastic polymer folded along at least one medial line (3) to define a folder (4) having opposing walls extending upwardly from said at least one medial line, each wall having an upper edge and side edges, characterized by: two separate thermoplastic polymer support bars (7), permanently fused one to each of said walls adjacent the upper edges thereof, on the inside of the folder with said sheet extending upwardly from lower edges of said support bars a substantial distance towards upper edges of said support bars, thereby providing integral reinforcement with said support bars, at least a portion (8) of the cross-section of said support bars being substantially greater in thickness than said sheet of thermoplastic polymer, said support bars having integral suspension portions (5) extending laterally from portions of said side edges adjacent said upper edges of said folder, said suspension portions having notches (6) therein configured to accommodate said suspension rails to support said folder assembly. 2. A file folder assembly as recited in claim 1 , where said folder has integral suspension portions (5) extending laterally from said portions of said side edges, corresponding to and aligned with said suspension portions of said folders, said suspension portions of said folders having notches (6) corresponding to and aligned with said notches of said suspension portions of said support bars. 3. A file folder assembly as recited in claim 1 , in which said support bars are provided with at least one reinforcing structural portion (8) extending therealong and projecting slightly therefrom, to provide additional strength and torsional and lateral rigidity. 4. A file folder assembly as recited in claim 3, in which said at least one structural portion comprises spaced-apart upper and lower ribs (8) extending along said support bars and projecting slightly therefrom, to provide additional strength and torsional and lateral rigidity. 5. A file folder assembly as recited in claim 1 , in which said support bars have a tapered lower portion which tapers downwardly from said substantially greater thickness to substantially zero thickness flush with said sheet, thereby reducing any tendency for any papers in said file folder to catch on said support bars during removal from said folder. 6. A file folder assembly as recited in claim 1 , in which said folder and said support bars are composed essentially of a polyolefin polymer. 7. A file folder assembly as recited in claim 6, in which said support bars have property enhancement fillers incorporated therein. 8. A file folder assembly as recited in claim 1 , in which there are at least two said medial lines (3) spaced slightly apart from each other so as to provide a generally U-shaped folder. 9. A file folder assembly as recited in claim 4, further comprising at least one indexing tab (9) mountable on said folder, each said indexing tab having an inside wall (10) and an outside wall (11) defining a U-shaped opening (12) between them, said U- shaped opening being positionable over one of said support bars, and said inside wall having a bulbous end portion (13) configured to be self-locating in a track (14) defined by said upper and lower ribs (8), each said indexing tab further having an upper indexing portion (15) extending upwardly above said inside and outside walls and having a portion (16) for carrying labeling indicia. 10. A file folder assembly as recited in claim 1 , where: said folder has integral suspension portions (5) extending laterally from said side edges, corresponding to and aligned with said suspension portions (5) of said folders, said suspension portions of said folders having notches (6) corresponding to and aligned with said notches (6) of said suspension portions of said support bars; said support bars are provided with spaced-apart upper and lower ribs (8) extending along said support bars and projecting slightly therefrom, to provide additional strength and torsional and lateral rigidity; said support bars each have a tapered lower portion which tapers downwardly from said substantially greater thickness to substantially zero thickness flush with said sheet, thereby reducing any tendency for any papers in said file folder to catch on said support bars during removal from said folder; and said folder and said support bars are composed essentially of a polyolefin polymer. 11. A file folder assembly as recited in claim 1 , where said sheet extends upwardly from lower edges of said support bars to be substantially flush with upper edges of said support bars.

Inventors: DEANS THOMAS W, MARK WALLACE N, DEANS, THOMAS, W., MARK, WALLACE, N.
Applicants: CANADIAN ENVIRONMENTAL OFFICE, DEANS THOMAS W, MARK WALLACE N, CANADIAN ENVIRONMENTAL OFFICE PRODUCTS INC., DEANS, THOMAS, W., MARK, WALLACE, N.
Application year: 1997
Main classification: B42F15
IPC codes: B42F15