US2176314A - Binding arrangement - Google Patents

Description

I Oct. 17, 1939. /J RUSSELL 2,176,314

BINDING ARRANGEMENT Filed Jan. 10, 1938 INVENTOR (/0572- fimzals' fizzsse/Z.

ATTORNEYS Patented Oct. 17, 1939 BEHTED T GFFICE 3 Claims.

' 'fiiis invention relatesto leaf-retaining devices and provides a leaf-retaining device which is particularly suitable for fabrication from fibrous cel-' lulosic sheet material such as laminated sheets 6 of so-called"flbre'made by consolidating a plurality of juxtaposed sheets of cellulosic material treated with zinc chloride or other reagent which causes the cellulose fibres to alter, thus adding strength, hardness and resilience to the mass.

The fibre best adapted to the manufacture of the leaf-retaining device of my invention is made by impregnating cotton rag stock with a relatively concentrated aqueous solution of zinc chloride, wrapping the stock in sheet form around a cylinder of large diameter to form a laminated annularrmass about 04 inch in thickness or say twice 'that desired in the flnal' product. The laminatedannular mass is cut and stripped from the cylinder as a sheet, and washed in a series of 20 aqueous zinc chloride baths of'diminishing concentration and finally with water alone. The v washed sheetis then dried and pressed flat to facilitate handling. During drying the sheet shrinks considerably in all directions and bei comes a strong m'ass about .02 inch thick.

A sheet thus produced has physical properties which are entirely different from those of Celluloid and similar materials heretofore employed in the manufacture ofleaf-retaining devices. 1

The resilience of .the sheet is considerable although less than that of Celluloid. Its surface is less smooth than that of Celluloid sheet and hence offers'a can be bent re dily ina relatively sharp angle or curvewithout breaking, whereas Celluloid and made. to adhere firmly to other fibrous surfaces through the use'of various forms? of cementing agents. Because-of its .yieldable character the 5 sheet does not tend tobreak away from a surface to which it has been cemented, even under considerable flexure. Moreover, the sheet isrelatively cheap and easily worked.

Because of its peculiar physical properties, the "flbre! sheet does not'form satisfactory leafretaining devices of the type heretofore fabricated from Celluloid and similar resilient'plastics. However, as a result of my investiga- -tions, 1? have developed a type of leaf-retaining device rvhich is well suited for manufacture from eater frictional resistance. It 7 fibre and results in an inexpensive, durable and convenient binding of attractive appearance. Accordingly, my invention contemplates a leafretaining device which comprises an; integral sheet of fibrous resilient material having an 5 elongated substantially flat back, a plurality of long teeth formed integrally with the back and projecting relatively sharply from one edge of the back and curved less sharply inwardly to ward the back with their free ends abutting the 10 back adjacent the opposite edge thereof, and a plurality of short teeth matching the long teeth formed integrally with the backand projecting relatively sharply from said opposite edge of the back and curved inwardly toward the back so that. theyoverlap the respective long teeth. In a preferred form of the structure according to my invention, the leaf-retaining device is fast tened inside a folder with the flat, back cemented or otherwise fastened to a back member of the folder between a pair of integrally formed overlapping covers. These and other features of my invention will be more clearly understood in the light of the following detailed description-taken in conjunction with the accompanying drawing, in which:

Fig. 1 illustrates a preferredform of the leafretaining device of my invention: and Fig. 2 illustrates an assemblyin which th leaf-retainihg device is placed within a folder. ,Oil Y Referring now to the drawing, it will be seen that the leaf-retaining device comprisesan elongated, substantially ,flat back. II made'of fibrous,

resilient material (preferably from flbre" of the Y from the edgethereof opposite the edge to which as. the long teeth are fastened. The short teeth also project from'the flat back through'a relatively sharp curve or angle ll, but are'less sharply curved throughout most of length, so that they'll: againstthe outside of and retain the 50 loosev ends of the long teeth.

The teeth preferably are relatively wide, say

' 4 inch, when the thickness of sheet from which they are made is about of an inch. In such circumstances the teeth should be spaced on I Leaves 23 to be retained by the device have 5 rectangular holes 24, 25, 2 in them through which the long teeth may be projected. In :fastening leaves into the retaining device, the long teeth are pulled out of engagement with the short teeth for enough to .leave a gap through which the leaves may be inserted. After the leaves are inserted, the long teeth are permitted -to resume their position inside the short teeth. This is facilitated'by bending the short teeth slightly outward. Because of the relatively sharp angle which the teeth make with the back member, the long teeth tend to push outwardly against the short teeth when a pull is exerted upon them. This increases the friction between the teeth and hence increases the security .with which the leaves are retained in the device. The relatively sharp curve or angle with which the teeth meet the back member is particularly desirable because of the nature of the material which tends to act as a hinge at the point where the teeth are joined 2.; to the back in preference to bending through the length of the teeth.

Referring now to Fig. 2, it will be seen that the binding element of Fig. 1 is fastened (preferably with some cementing agent such asglue) to the inside of a flat folder back I! which is substantially the same width. as the back of the leaf retaining device, but slightly longer. The back of the leaf-retaining device may be fastened to the folder back by means of rivets (not shown) but ordinarily the best course is to employ a cementing agent. lilormed integrally with the back of the folder andbent so as to overlap the leaf-retaining device are a pair of covers 20, 2! which overlap the leaf-retaining device and protect the retained leaves.

In manufacturing the leaf-retaining device of my invention, the fibre described hereinbefore is cut into the desired flat shape, moistened with water, and'bent over a mandrelor other form to conform to the shape shown in Fig. 1. The moistened fibre is then dried on the form. Efforts. to.

dry the moistened leaf-retaining device while unsupported will usually be unsatisfactory because warping and distortion tend to occur.

securely thereby because of the tendency of the long teeth to force outwardly against the short When the leaves have been inserted in the finished leaf-retaining device, they will be held an adequate manner, it is desirable in some instances, and particularly when the resilient fibrous material from which the leaf-retaining device is made has an exceptionally smooth surface, to upset a portion of both long teeth and short teeth where they overlap so that a depression is formed on either the long tooth or the short tooth and a corresponding nub or projection is formed on the other tooth and fits into the depression. The depression and projection may be formed conveniently while the material is moist, simply by pressing a hard round instrument against the overlapping teeth. In Fig. 1, depressions 2'! are shown punched into the outer surface of short teeth I5, ll, respectively, so that on the inner portion of these short teeth there are corresponding projections. Similarly, on the inner surface of the overlapped long teeth ii, l3, depressions are formed into which the projections on the short teeth fit. A similar result is 010 tained with the teeth l6, l2, by upsetting the two from the inside, so that a projection 28 is formed on the upper surface of the tooth it, a corresponding projection on the tooth i2 fitting into the resulting depression on the lower surface of the tooth i6.

i claim? 1. A leaf-retaining device which comprises an integral sheet of fibrous, resilient material having an elongated sumtantially flat' back, a plurality of short curved teeth spaced along and projecting relatively sharply from one side of said back, and a plurality of matching long curved teeth spaced along and projecting relatively sharply from the other side of said back, the long teeth extending in a less sharp arc to the opposite side of thefiat back and abutting substantially perpendicular thereto, with the short teeth overlap- 'ping and fitting against the outer surfaces of the rality of short teeth matching the long teeth,.

said short teeth being formed integrally with the. back and projecting relatively sharply from said opposite edge of the back and curved less sharply but inwardly toward the back throughout most of their length so that they overlap and fit,

against therespective long teeth. I g

3; Apparatus according to claim 2 in which the distance between centers of the teeth is approxiwidth of the teeth.

mately twice the JOHN FRANCIS RUSSELL

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