Method of making binders and split rings therefor

Nov. 6, 1945.

C. E. EMMER

2,388,397

METHOD OF MAKING BINDERS AND SPLIT RING THEREFOR

Original Filed Jan. 2, 1943

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Patented Nov. 6, 1945

2,388,397

UNITED STATES PATENT OFFICE

2,388,397

METHOD OF MAKING BINDERS AND SPLIT RINGS THEREFOR

Charles Edward Emmer, Chicago, HI., assignor to General Binding Corporation, Chicago, Ill., a corporation of Illinois

Original application January 2, 1943, Serial No. 471,175. Divided and this application April 26, 1943, Serial No. 484,530

Claim. (CI. 18—48)

This invention relates to a binding structure particularly adapted for use in the binding of papers, magazines, books and the like, and more particularly to a new method of making a binder and a split ring therefor. ,5

The subject matter of this application has been divided from my copending application Serial No. 471,175, filed January 2, 1943, issued on November 28, 1944, as Patent No. 2,363,848.

An object of this invention is to provide a new io method of making a binder haying a split ring structure for use in the binding of loose leaf papers and the like whereby a strip of synthetic plastic material may be utilized to provide in the binder flexibility for the opening of the ring por- 1.5 tions as well as for the opening of the sides or ’ cover of the book.

Another object of this invention is to provide a method of making a binder ring structure which . includes the step of imparting flexibility to the 20 ring structure by the plasticizing of an intermediate portion of the ring structure.

Still another object of the invention is to provide a simplified method of forming a ring structure whereby inherent features of the material of 25 the ring structure may be utilized in the provision of flexibility in the ringstructure.

In accordance with the general features of this invention, there is provided a method of making a binder ring which comprises forming from a ³⁰strip of synthetic plastic material a binder ring having opposite portions cooperating to define a split ring at one side, and joined at their other side by a connecting base portion, and thereafter subjecting the base portion to the action of a 35 plasticizer for rendering the base portion more flexible, whereby the base portion may be flexed to permit of the separation of the opposite ring portions of the ring.

Another feature of the invention relates to the ⁴⁰forming of the sides of a book or the like from the same type of material as is used in the imparting of flexibility to a split ring structure in the book.

Other objects and features of the invention will ⁴⁵more fully appear from the following detailed description of several forms of articles made in accordance with the methods of my invention and wherein:

Figure 1 is a perspective view of a binder strip ⁶⁰embodying the features of this invention;

Figure 2 is a cross-sectional view through a portion of the strip of Figure 1 showing the manner in which it cooperates with ring portions to define a split binder ring;

Figure 3 is a view similar to Figure 2 but showing the manner in which the opposite ring portions may be spread apart by flexing the intermediate connecting portion of the base strip;

Figure 4 is a view similar to Figures 2 and 3 illustrating a modification of the invention wherein the ring portions, instead of being integral with the base strip, are attached to the base strip;

Figure 5 is a view similar to Figure 4 showing how the cooperable ring portions may be separated by the flexing of the portion of the base strip connecting such portions and also showing in dotted lines a modification wherein the base strip may be formed integral with the sides or cover of a book or pamphlet;

Figure 6 is a view partly in section and similar to Figure 2 of a still further modification of the invention wherein the portion for connecting the opposite ring portions embraces both the upper and bottom sides of the adjoining connected ends of the ring; and

Figure 7 is a view similar to Figure 4 but illustrating a further modification.

As shown in the drawing:

• It is believed that my novel methods of making a binder and a split ring structure therefor, will be best understood from a description of several forms of binder structures made in accordance with the steps of the methods.'

Reference character 10 designates generally a flat strip of synthetic plastic material from which are integrally formed a plurality of spaced split binder rings II. It is to be understood that any number of rings may be formed from the strip as desired and that my invention is not only applicable to a strip having a plurality of rings but is also applicable to a single plastic ring such as is shown in the modification of Figure 6.

Each ring II has diametrically opposite ring portions 12—12 cooperable in abutting relation at their opposite ends and defining a split 13 between the opposite ends. The other ends of the ring portions 12 are connected by an intermediate portion of the strip proper designated in Figure 2 by the reference character 14.

It should be noted at this time that I have not used the term “ring” in the sense that the ring must be a true circle since it is evident from Figures 4 and 5 that the ring may equally well have a non-circular shape. Accordingly, when I have used the term “ring portion,” I refer to a binder ring having a split therein with opposite portions that are adapted to be separated to permit the application of the ring to sheets to be

2,388,397 bound, such, for example, as loose leaf sheets or the like.

In the modification of Figure 4, the ring portions 12', instead of being formed out of the base strip 10', are in reality separate portions which are suitably fastened to the base strip f 0' by a suitable plastic binding material or adhesive of which there are many different brands on the market, and such as a vinyl lacquer. In this form, it will be noted that each ring portion 12' has an inwardly bent leg portion 15' which is attached to the strip 10'. The two leg portions 15' are separated by an intermediate flexible base portion 14' in the strip 10'.

Attention is also directed to the fact that, in Figures 3 and 5,1 have illustrated the manner in which the rings of Figures 2 and 4 are adapted to be opened by the flexing of the intermediate connecting base portions 14—14'.

It should also be noted that, in the forms of invention shown in Figures 1 to 3, only a small portion of the base strip may be treated by a plasticizer to make that portion flexible. On the other hand, in the other forms of the invention illustrated herein, the entire base strip may be cut from a plasticized sheet of synthetic plastic material so that the entire base strip is more flexible than the relatively more rigid ring portions.

Also, in Figure 7 I have illustrated by dotted lines at (Qb a base strip, which illustration makes it clear that the base strip may be applied to the top sides of the legs 15'—15' as well as to the bottom sides as shown in Figure 4. In either event, whether the base strip is on the top or on the side of the adjoining legs of the ring portions, it serves 35 to provide a flexible connection between the connected extremities of the ring portions.

Figure 5 illustrates the manner in which a ring structure, such as that shown in Figure 4,. may be opened and further shows by dotted lines at 20—20 how the base strip 10' may constitute an integral portion of the sides or cover of a book. The dotted line portions 20 show the sides or cover of the book when the book is opened, and these sides or cover may constitute portions of the same sheet from which the base strip (O' is formed.

Excellent and economical results can be attained from such a structure, particularly where the base strip and the sides or cover of the book are made from sheet plastic material, such, for ⁵⁰example, as a plasticized vinyl resin or a rubberlike material (natural or synthetic) or any other suitable material. In such a modification, the portion of the plastic sheet joining the two sides 20—20 serves as a flexible back for the book and also as a flexible connection between the juxtaposed extremities 15'—15' of the ring portions 12'—12'.

In Figure 6, I have illustrated a still further modification of the invention in which ring portions 12a, instead of being attached or integral with a base strip, are connected by a connector ΓΟα, which may be of arcuate configuration if desired. The connector 10a may be attached to the adjoining ends of the ring portion 12a—12a by any suitable plastic binding or cementitious material of which there are many brands on the market, as noted before.

The connector 10a has an intermediate flexible portion (4a which the opposite ring portions 12a—(2a are adapted to flex when the split ring is opened to permit the introduction of sheets to be bound by the ring. It will be understood that, in the use of these rings of my invention, they are applied to sheets in the usual way through the conventional holes in the sheets spaced apart for the reception of binder rings.

The connector 10a may be in the form of an individual sleeve for each ring or may comprise a portion of an elongated strip for a multiple of the rings and which strip has a plurality of transverse openings for the reception of the ends of the ring portions 12a—12a to be connected together. If desired, the connector 10a may comprise two strips of plasticized synthetic plastic sheet, one on the top of the extremities of the ring portions and the other on the bottom, and which strips are suitably cemented together by means of a plastic binder.

In Figures 4, 5, and 6, the sides or cover of the book may be formed integral with the base strip if it is so desired; this is exemplified by the structure shown in dotted lines at 20—20 in Figure 5.

An advantage of the ring structures shown in Figures 4, 5, and 6, wherein the ring portions each comprise substantially one half of the ring, resides in the fact that this structure lends itself to a press formation or injection or compression molding with thermo-setting material. In other words, each ring half may be economically fabricated from suitable plastic material in a press operation, thereby eliminating the need for a coiling operation such as used in the formation of continuous ring structures shown in Figure 1.

The rings could be made of other material such, for example, as metal, wood or fiber, if it was so desired, as long as such rings were fastened to a plastic or a synthetic resin backing strip adapted to flex in the opening and closing of the rings.

Now, in the use of these split binder rings it is desirable that they be made relatively rigid so as to withstand the wear and tear incident to their use and so that they will perform their intended binding functions. On the other hand, there must be sufficient flexibility at the connecting junction of the opposite ring portions so that they may be easily and resiliently flexed open and shut. In accordance with the features of this invention, I propose to provide the requisite resiliency at the connecting junction of the ring portions by so treating the plastic material at the junction portion that it will have greater resiliency and flexibility than the material of the ring portions proper.

It should be noted that the synthetic plastic used in the making of the rings disclosed hereinabove may be made of any of the now well known plastics on the market. For illustration, the ring portions may be made of a synthetic thermo plastic material such as the so-called vinyl ester resins. These resins are now available on the market in a number of different forms, such as polyvinyl acetate, polyvinyl chloride, and copolymerized vinyl chloride and vinyl acetate. The synthetic plastic used may also be of the socalled nylon type, which is the generic name for all materials defined scientifically as synthetic fiber-forming polymeric amides.

I also contemplate the use of synthetic materials of the type referred to as acrylics or of the type referred to as cellulose acetates. The characteristics of such synthetic thermo plastics are now well known, as will be evident fr.om the 1942 Plastics Catalog published by Plastics Catalogue Corporation. Therefore, in referring to these plastics, I refer to them in the same sense as they are referred to in the aforesaid publication.

It is also well known that certain plastics may

2,3!

be softened or rendered less brittle or more flexible by treating the same with a plasticizer. The plasticizers for the different synthetic plastics are also well known in the art, as is evident from the aforesaid publication.

In accordance with the feataures of my invention, I propose to apply a plasticizer solely to the connecting junction piece of my binder ring structure, such as the pieces 14, 14', and 14a. By subjecting each of these pieces alone to the action of a plasticizer, which in some cases may be a solvent, only this connection is rendered more flexible and the remaining rigidity of the ring is not affected.

When a synthetic thermo plastic in the form of a vinyl resin is used, I have found that the desired plasticizing action may be effected by the use of esters, certain halogenated hydrocarbons, ethers, certain amines, and by lower aromatic hydrocarbons. Such a plasticizer is only applied to the restricted connecting piece between the joined ends of the split ring so that this piece will be rendered more resilient thereafter.

It will, of course, be understood that various

1,397 3 details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon 5 otherwise than necessitated by the scope of the appended claim.