US3613281A - Plastic file folders - Google Patents

Abstract

FILE FOLDER OF PLASTIC HAVING THICKENED SECTION AT CRITICAL WEAR ZONES. THE FILE FOLDER IS MADE FROM TUBULAR PLASTIC EXTRUDING IN SUCH A MANNER AS TO HAVE THICKENED ZONES AT DIAMETRICALLY LOCATED PORTIONS. THE TUBING IS THEN FLATTENED WITH THE FOLD POINTS CENTRALLY OF THE THICKENED ZONE. LASTLY, THE FLATTENED TUBING IS TRIMMED ADJACENT A FOLD TO ELIMINATE THE BIGHT BUT TO LEAVE THICKENED FREE EDGES.

Description

Oct. 19, 1971 w. LENNARTZ 3,613,331

PLASTIC FILE FOLDERS I Filed March 6, 1970 s H r 3 I8 i 17 1g 23 FIGA F|G.5 21 FIGS INVEN TOR. W41 7t? zM/w/Prz M, w W

United States Patent '6 3,613,281 Patented Oct. 19, 1971 hoe 3,613,281 PLASTIC FILE FOLDERS Walter Lennartz, 9/ BRD Waldstrasse, 806 Rothschwaige, near Dachau, Germany Filed Mar. 6, 1970, Ser. No. 17,120 Claims priority, application Germany, Mar. 7, 1969, P 19 11 729.4 Int. Cl. B42f 7/00 US. Cl. 40-359 3 Claims ABSTRACT OF THE DISCLOSURE File folder of plastic having thickened sections at critical wear zones. The file folder is made from tubular plastic extruding in such a manner as to have thickened zones at diametrically located portions. The tubing is then flattened with the fold points centrally of the thickened zone. Lastly, the flattened tubing is trimmed adjacent a fold to eliminate the bight but to leave thickened free edges.

The invention refers to a plastic folder with a fold connecting abase sheet and a cover sheet and at least one open page opposite to the fold of the folder.

Folders su h as binders, hanging binders and file folders, which are closed on two sides, are mostly made of cut foil material and, therefore, have uniform thickness. However, not all parts of a folder are stressed equally throughout when used. In fact, the most frequent premature wear and damage takes place at the folds and at those free edges which must be handled to open the folder. For that reason, folders made of foil material are made too large, particularly at those places which are subjected to less stress. Because these latter parts are usually larger than the rest of the folder, to make them larger is highly wasteful and uneconomical. Above all, it must be recognized that these folders are produced in quantities of millions of pieces.

File folders which are closed on three sides are known to be made of flattened pieces of tubing from tubing sections made by extrusion (DBP 1,039,484). In this way a wasting of material may be prevented with pockets. In the same patent for the manufacturing of file folders which are open on three sides, it is recommended to partition such a flattened piece of tubing lengthwise between the two bends.

The file folders open on three sides made in such fashions, however, show very thick free lengthwise edges.

The invention is based on the concept of making plastic folders in such a way that they can be produced with a minimum quantity of material in a simple, largely mechanical fashion.

In order to achieve this goal, the invention provides for the three edges of the base and cover sheet which are opposite to the back fold to be stiff, inasmuch as the folder is made of a flattened tubing section with thickened fold areas, one of which is cut away to create the reinforced free edges.

In this manner, the frequently used free edges of the folder are reinforced without any additional effort or separate reinforcing parts, independently of the making of the folder fold, which can, for example, be made to accommodate in its hollow part a suspension bar put through the narrow part of the folder, or which can be made as a reinforced, profiled suspension wall for hanging in Pendaflex type files. It is to be pointed out that the dimension of the reinforcement can be adjusted without any difficulty according to type of folder. It is simply necessary to exchange the nozzle in the extrusion head, in order to obtain a tubing with the desired thickness. The cutting off of the fold can be done in one die stamping operation when the flattened tubing is cut to its proper length. Should a welding be required, for example in the production of two-sided closed file folders at the lower edge, the cutting away of the one fold can either entirely or in part be done also in one operation by using a heated cutter.

In the drawing, working models of the invention are illustrated. These show:

FIG. 1 is a two-sided closed file folder in three dimensional perspective;

FIG. 2 is a cross section of a flattened plastic tubing with reinforced fold areas, the tubing which is the basic form for all shown folders;

FIG. 3 is a variation of folder as shown in FIG. 1;

FIG. 4 is a folder with a ribbon for filing in sequence;

FIG. 5 is a hanging folder with a suspension bar in the back fold;

FIG. 6 is a hanging folder with a profiled hanger edge.

The first step in the production of all folders illustrated in the drawing, i.e. such with free edges opposite to the back fold, is the tubing section, shown schematically in FIG. 2 in cross section. Plastic tubing of this type is Commonly made by the extrusion process, namely by urging the synthetic material in plastic state through an annular nozzle and by simultaneously forcing compressed air into the inside of the tubing which will enlarge the tubing to the desired dimensions while it is still in a plastic state, and at the same time will cool the walls until they have solidified. The annular nozzle is provided with the proper enlargements which allow in the tubing for two thickened areas at opposite sides. After solidification of the tubing, it will be flattened in convenient manner so that the thickened areas are now the folds of the flattened tubing section.

For clarity FIG. 2 shows the fold areas 1 and 2 drawn thicker than they are actually made. Area 3 of the entire tubing section, labeled as 4, consists of a very thin foil so that its total weight is relatively small.

To obtain a lengthwise open end of the folder during production, the fold 1' is out along the dotted line 5. In this way free lengthwise edges of the folder are created which are thickened in a given area. Because of the thickening of the edges, usually enduring the most stress and wear, the life-span of these folders is considerably increased.

FIGS. 1-6 show schematic illustrations of the folders whereby the thickened areas of the covers are omitted. These areas are found in all these folders, because they are basically made out of one and the same type of tubing section as illustrated in the cross section of FIG. 2.

FIG. 1 shows a file folder closed on two sides, whereby fold 2 of the tubing 4 forms the back of the folder. The cover sheet 6 and back sheet 7, attached to the back 2 in the same manner, show in their central areas 3 a very small thickness. In the areas of their lengthwise edges 8 and 9, however, the cover and back sheets 6 and 7 show a reinforcing as shown in the fold area 1 of FIG. 2. Fold 1 is then cut off along the entire length of the twosided closed file folder.

In the production of such two-sided closed file folders, the tubing is either first cut into sections and then the lower edge 11 is closed with the sealing seam 10, or in one single operation the seam 10 is applied and with the aid of a hot cutter the fold 1' of the flattened tubing is cut away, while the separation of the file folder from the tubing is achieved by applying a hot cutting along the lower edge.

Whenever the wall thickness in the area 3 as compared to the fold areas 1 and 2 is considerably different, it may be advantageous to apply the weld seam 10 only in the intermediate area 3, or perhaps to divide this weld seam into two partial seams, each of which is arranged in a 3 thickened fold area. FIG. 3 shows a variation of the two-sided file folder as illustrated in FIG. 1.

The fold 1 of the flattened tubing 4 is not cut away over the entire length of the open side of the folder. Instead, in the area of the lower edge 11, a remaining fold 12 is left. Thus, fold 12 is an additional support for any file contained in the folder, and is achieved without any additional operation.

The area of the free lengthwise edges 8 and 9 is, in this case, also reinforced. Particularly the upper right corner 13 of such a two-sided closed file folder will profit by such a reinforcement, because the file folder will always be opened at this corner 13. The opening of the cover sheet 6 is facilitated by the fact that it is in its central area 3 very thin and will therefore bend easily.

FIG. 4 shows schematically a folder which is made of a tubing section 4. The cover sheet 14 and the back sheet 15 are connected by the reinforced fold 2. They show free lengthwise edges 16 which are obtained by cutting away fold 1' of the flattened tubing 4. Through the transparent cover sheet 14 a strip 17 is visible which is attached to the back sheet 15 on its inside with the aid of an interrupted weld seam as the holder of a strip for sequential filing. The strip could be attached to the back sheet by other means as well.

FIGS. 5 and 6 show hanging folders which do not illustrate the threading provisions for purpose of better clarity. The hanging folder according to FIG. 5 is characterized by a hanging rail 20, attached to the inside of {old 2, which extends in the usual fashion beyond the narrow side of the hanging folder, and thus can be hung in horizontal files. In this case, the area of the free lengthwise edges is also reinforced by starting the production of such hanging folders with the same type of tubing section 4, the fold 1 of which is cut off. The cutting to proper length and the cutting of fold 1' can be achieved in one die stamping operation. For attaching the suspension rail 20 to the back of the hanging folder, the strip 17 shown in FIG. 4 may be used by arranging the weld seam 19 at such a distance from fold 2 that the rail may simply be inserted into it. The strip 17 in this case not only serves as support for the sequence ribbon but also as holder of the suspension rail 20.

FIG. 6 shows a hanging folder for well-known Pendaflex files. The hanging folder indicates a profiled hanging rim, labeled in its entirety as 21, which extends in its width over the thickened area of fold 2. The area which is indicated in this drawing as 22 is considered of great advantage, inasmuch as the two thickened layers of adjoining tubing walls are connected by a flat seam welding, so that the hanging protrusion 23 has sufficient strength to hold in the support rail any file material in the folder. The open rim exclusion 24 can be achieved simultaneously while applying the flat seam welding with the aid of a specially formed plastic welder. This hanging folder distinguishes itself also through the free lengthwise edges 16 of back sheet 15 and cover sheet 14 which are in the proper areas reinforced as a result of cutting fold 1 off of the flattened tubing 4. The attaching of a threading device, in this case, can be most advantageously achieved by inserting into the fold 2 of tubing 4 a respectively wide strip of plastic which is then attached to the walls of the tubing by a flat seam, whereby the open rim recess 24 is also cut into this strip by the hot cutter, so that this strip simultaneously serves as reinforcement of the hanging protrusion 23. A portion of this strip extends freely into the interior of the folder and serves as support of the threading ribbon.

All illustrated and described folders have the special characteristic that the free lengthwise edges of the folders are reinforced because of the high degree of wastage of these parts, while the area 3 of the folders which are stressed much less may be kept very thin, i.e. a thickness of only a few ths of a millimeter. Therefore, the weight of such folders is considerably less than that of similar conventional folders currently on the market, a consideration not only from the point of economics, but also from the point of handling them. This is particularly the case with the hanging folders, because their weight adds considerably to the stress and wear of support rails in register cabinets.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Plastic file folder comprising a back sheet and a cover sheet made from one piece, said sheets having a common hinge portion along one of their edges, said sheets further having free edges parallel with and opposite to said hinge portion, said hinge portion and said free edges have a gradual tapered thickened cross-section, so that the edges adjacent said hinge portion and said free edges have the greatest cross-sectional dimension.

2. Plastic file folder according to claim 1 wherein one of the cooperating edge portions of said sheets extending laterally away from said hinge portion are fastened togethcr.

3. Plastic file folder according to claim 2 wherein a portion of said edges are fastened together.

\ References Cited UNITED STATES PATENTS 3,424,167 1/1969 Lennartz 40359 FOREIGN PATENTS 1,156,616 7/1969 Great Britain.

1,168,294 10/1969 Great Britain.

ROBERT W. MICHELL, Primary Examiner I. H. WOLFF, Assistant Examiner U.S. Cl. X.R. 40l02, 104.19

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