US1868793A - Loose leaf binder - Google Patents

Description

July 26, 1932. J, C, DAWSON 1,868,793 LOOSE LEAF BINDR Filed Feb. 28, 1951 v gigs 16 instance,

Patented July 26, 1932 UNTED STATES PATENT OFFICE JAMES C. DAWSON, OF VJEBSTER'GROVES, MISSOURI,.ASSIGNOR TO ELMA N. DAWSON,

OF WEBSTER GROVES, MISSOURI LOOSE LEAF BINDER Application filed February v28, 1931. Serial No.'519,134.

This invention relates to loose leaf binders and has for its objects to provide means to assemble loose leaf binders of the spring cover type to book backs; to provide sim- 5 ple means for holding booster levers on binders of such a type; and to secure the closing of the end pairs of paper-holding prongs with a pressure which equals or exceeds that closing the intermediate pairs.

In binders of the spring cover type, it has been customary to rivet the binder mechanism to the book back. It is, however, preferable to have the binder detachably connected to the book back for in ythe latter the requirements of the trade can be met with fewer type of covers and binder mechanisms.

These and other objects and advantages of the invention will become apparent from 20 the specication and the appended drawing,

in which Fig. 1 represents a loose leaf binder shown in perspective;

Fig. 2 is a longitudinal, vertical section of a portion of the binder illustrated in Fig. 1;

Fig. 3 is a bottom plan view of that portion of the binder illustrated in Fig. 2;

Fig. 4 is a vertical, transverse section of the binder mechanism on the line 4-4 of Fig. 2;

Fig. 5 illustrates the method of assembly of the spring cover plate to the binder mechanism; and

Fig. 6 is a perspective view showing in detail the booster lever, the spring clip and a portion of the toggle plates.

Loose l-eaf binders of the type illustrated in Fig. 1 comprise two articulated toggle plates 11 and 12, bearing the paper- holding prongs 13 and 14 arranged to mate with the opposing prongs. A spring cover plate 15 engages the toggle plates along their outer margins and applies pressure in such a way that a dead center mechanism is formed which either `forces the prongs into engagement or holds them apart.

I attach the binder to the book back by providing small reliefs 16, 16 cut in the outer edges of the toggle plates near each close of their ends and hookingfthe curved margins of a clip 18 over the plates at these points. The clip is curved to fit the book back 19 and bears anaperture 21 through which a loop 22 struck up from the back projects and over'which a key 23 is 'thrust to lock the binder to the back..

`Thebooster lever 124, a type more particularly disclosed in a companion apphcation, comprises a thumb arm'25, `a vertical arm A26, and a toggle-operating arm 27. As indicatedin the figures, two slots 28, 28 are cut into the vertical arm 26 which'are initially engaged by the bevelled nose 29 of a latch` 31A forming a terminal extension upon each of the toggle plates.

The assembly of thedevice is as follows: The clips 18,18 are sprung over the toggle plates 11 and 12 sojthat rtheir hooked margins 17 engage the relieved portions 16, 16. The articulating buttons 32, 32 hold the plates in proper position. The booster lever is then placed so that the bevelled nose 29 of the latches 31 engage the slots 28 and the arm 27 extends beneath the toggle plates, as indicated in Fig. 4. When the end ofthe thumb arm 25` is pressed inwardly, the

plates are forced apart against the pressure of thespring clip 18 and, asthe latchespass the arm 26, the plates spring back into place and hold the booster lever permanently in position. v l

- The-spring cover plate is next applied. as

is indicated in Fig. 5,' by rst forming it in v se p the spring plate 18. Then the key 23 is thrust under the loop and over the clip.

The common diiiiculty with loose leaf binders is the fact that the spring which closes the prongs may really be considered as comprisingthree springs, that tending to the Central pair being substantially engaging the outer edges of longer and consequently much more powerful than that tending to close the outermost pairs of prongs. Sometimes, the prongs do not close at all but gape apart slightly and frequently the ends catch in the paper leaves and tear them as the pages are turned.

Since the clip 1S is a spring section, its strength is added to that of the spring cover l5 and, therefore, the end pairs of prongs may be made to close with a pressure equal to or in excess of that tending to close the central pair of prongs.

Although, as I have explained, a spring clip has particular advantages, in so far as attachingthe book is concerned, the clips 18 may be relatively rigid, and in that case the distance between the hooked margins 17 is as great as the length of the straightened toggle. The slight looseness that results is hardly noticeable in handling the book.

'Vhat l claim, therefore, is:

l. A loose leaf binder having a pair of articulated toggle plates bearing a plurality of paper-holding prongs arranged in mating pairs, an arched spring` cover plate engaging the outer edges of the toggle plates and normally urging the prongs into engagement` and means including a spring clip extending beneath the toggle plates to cause the end pairs of prongs to close with a pressure at least as great as that tending to cause the engagement of those intermediately placed.

2. A loose leaf binder having al spring cover plate provided with hooked margins, a pair of articulated prong-holding toggle plates having their outer edges engaged by such hooked margins, a back, and means to c hold the binder assembled to the back including an arched clip engaging the toggle plates and extei'iding beneath them, and means to lock the clip to the back.

3. A loose leaf binder having a pair of articulated toggle plates bearing paperholding prongs, a portion of the outer edge of each plate being recessed adjacent each of its ends, an arched clip having hooked margins engaging the recessed portion of the edge and extending beneath the plates and provided with means whereby the binder may be attached to the back, and a spring cover plate having hooked margins engaging the toggle plates upon their outer edge.

A loose leaf binder having a pair of articulated toggle plates provided with paper-holding prongs and having a recessed portion upon the outer edge of each plate, a spring cover plate having hooked margins the toggle plates, a clip having hooked margins engaging the recessed portion of the plates and extending beneath them, a back, a loop upon the back, an aperture in the clip adapted to engage the loop, and a key eX- tending over the clip and under the loop for holding the binder assembled to the back.

5. A loose leaf binder having a pair of articulated toggle plates bearing a plurality of paper-holding prongs arranged in mating pairs, an arched spring cover plate engaging the outer edges of the toggle plates and normally urging the prongs into cngagement, and means to cause the end pairs of prongs to close with a pressure at least as great as that tending to cause the engagement of those intermediately placed, which comprises a short arched spring section located adjacent to each end of the plates and provided with hooked margins engaging the outer edges of the toggle plates.

In testimony whereof I atlix my ture.

signa- JAMES C. DAVSON.

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