Book leaf indexing arrangement
United States Patent 1 Friedman Apr. 15, 1975 BOOK LEAF INDEXING ARRANGEMENT [76] Inventor: Arthur S. Friedman, 509 Madison Ave., New York, NY. 10022 [22] Filed: Nov. 7, 1973 [21] Appl. No.: 413,697  
 Primary ExaminerLawrence Charles Attorney, Agent, or Firm-Dennison, Dennison, Townshend &amp; Meserole [57] ABSTRACT A book comprising a sequential series of separate groups each consisting of a plurality of consecutive leaves, and front and back covers, has an indexing side edge marginal zone of narrow width between its top and bottom edges. The first page of the first leaf in each group bears in its marginal zone indicia identifying its particular group. The indicia characters are arranged in longitudinal sequence. The index side edge of the front cover is recessed to provide a sight aperture which extends over the full length of the indicia sequence coterminous therewith. Each group of leaves is similarly recessed with an index sight aperture different in length than any other sight aperture of the book. Beginning with the group of leaves immediately following the front cover, the sight aperture of each group is successively shorter in length than the aperture of its immediate predecessor. A transparent plastic window associated with the front cover overlies the entire sequence of the sight apertures. The lower ends of all sight apertures terminate in registry at and with the lower end edge of the cover sight aperture at a point spaced above the bottom edge of the book.  
 1 Claim, 3 Drawing Figures BOOK LEAF INDEXING ARRANGEMENT BACKGROUND The field of the present invention is the art of book leaf indexing.  
  The prior art in general makes use of leaf-associated visual aids arranged for quick selection of clearly identified different portions or sections of a book. Some examples of such aids are leaf-attached edge tabs. thumb notch cut outs, leaf edge grooves. etc. For the most part, such aids are not accessible for viewing so long as the front cover of the book is closed. and when the cover is opened for thumbing the leaves, those aids that are associated with the leaves proximate the bottom edge zone of the book are subjected to greater flexation and consequent greater wear and tear than those aids associated with upper portions of the book leaves. This is particularly true of small books such as personal telephone directories. address books. pocket dictionaries. memorandum booklets and the like.  
 SUMMARY OF THE INVENTION In the book of the present invention the leaves are arranged as a sequential series of separate groups individually identified by appropriate indicia on the first page of the first leaf in each group. All the indicia characters are arranged in linear sequence extending longitudinally intermediate the top and bottom edges of the book in a narrow marginal zone at its index side edge and are visible through a transparent plastic window associated with the front cover. The index side edge of the cover has a longitudinal cutout recess intermediate its top and bottom edges which provides a sight aperture extending over the full length of the sequence of indicia. whereby they are visible through the closed cover and the plastic window means associated therewith. Each group of leaves is similarly formed with an individual index sight aperture of successively shorter length such that no indicia character of any group is concealed or overlapped by any portion of the group which precedes it. The uncut marginal zone portions of the cover and leaves between the lower end of the indicia sequence and the bottom edge of the book are of identical size and shape and are in precise registry, thereby providing reinforcement which prevents undue flexing of the lower end portions of the leaves.  
 DRAWINGS FIG. I is a perspective view of the book comprising the present invention, with the cover in closed position.  
  FIG. 2 is a section through the front cover on line 2 2 of FIG. 1.  
  FIG. 3 is a perspective view of the front cover, window sheet. and the first two leaves. all in partly open position. of an alternative arrangement of the book assembly.  
 DETAILED DESCRIPTION In the specific embodiment herein disclosed, the book includes a front cover 10 of flexible cardboard or the like. a back cover 11 of similar material. and a plurality of flexible paper leaves 12 therebetween. The front cover is encased in a sheet of flexible transparent plastic 13 folded upon itself at its mid portion to engage over the indexing side edge of the cover in contact with the outer and inner faces thereof and with the free ends of the sheet flush with the opposite side edge of the formed with a narrow longitudinal sight aperture having its inner edge 15 spaced inward from the bight of the transparent plastic sheet 13 and parallel thereto. Each end of the sight aperture terminates inwardly from its adjacent top or bottom edge of the cover and is spaced sufficiently from the edge to leave substantial marginal zones 16 and 17 of the cover extending between the end of the sight aperture and the adjacent top or bottom edge of the cover. These cover portions reinforce the plastic sheet 13 bight portion and prevent undesired flexation thereof.  
  In the front cover arrangement shown in FIG. 1, the upper marginal zone portion 16 of the cover and the corresponding face areas of the plastic sheet 13 are cut out to provide an arcuate thumb-receiving recess 18. In the arrangement shown in FIG. 3 the thumb recess is eliminated. In an alternative arrangement (not shown). the recess 18 may be simply an extension of the index sight aperture.  
  Each leaf 12, in its indexing side edge area underlying the index sight aperture of the front cover 10, is formed with an individual sight aperture identical to the cover sight aperture in all respects except length. Preferably. the leaves are arranged as separate groups. each comprising a plurality of consecutive leaves in which the index sight apertures are in registry and identical in all respects. The sight apertures common to any individual group are different in length from any other group, and the first page of the first leaf in each group is provided with indicia l9 distinctively identifying that particular group. As best seen in FIG. 3, the indicia in each case is located immediately above the upper end of the index sight aperture of the leaf on which it appears, and in longitudinal alignment with the aperture.  
  The index sight aperture in the front cover 10 is the greatest in length. The sight aperture common to the first group of leaves following the cover is shorter in length by the amount of space at its upper end that is occupied by the identifying indicia for that group. In like manner, the sight aperture individual to eachsucceeding group is similarly shorter in length than sight aperture of its immediately preceding group. At their lower ends, however, all the sight apertures of the leaves terminate in registry with and at the upper edge of the lower marginal zone portion 17 of the front cover 10. In consequence, each leaf has at its lower end and index margin portion 20 corresponding exactly to the marginal zone portion 17 of the front cover, as best seen in FIG. 3. The provision of these portions 20 is a salient feature of the present invention. Each leaf portion 20 covers and protects the one immediately following it. In effect. the superposed portions 20 constitute a stack which reinforces the lower end area of the index side edges of the leaves against undue flexing.  
  In the arrangement illustrated in FIG. 3, the transparent plastic sheet 13 which encases the front cover in FIG. 1 is eliminated and replaced by a single transparent plastic sheet 21 inserted between the front cover and the first one of the leaves. The index side edge portion of the sheet 21 overlies all the index sight apertures of the leaves.  
 I claim:  
  1. In combination: a book having front and back covers, separate groups of consecutive leaves therebetween, one side edge of the front cover having therein a longitudinal recess intermediate its top and bottom edges and constituting an index sight aperture. each group of leaves having in each leaf thereof an index sight aperture similar to and in registry with the front cover sight aperture, the length of the sight apertures common to each separate group of consecutive leaves being shorter than the length of the front cover sight aperture and being successively shorter from their upper to their lower ends the first page face of the first leaf of each group of leaves having thereon indicia identifying that particular group and located in the area between the upper end edge of the sight aperture in the leaf on which it appears and the upper end edge of the sight aperture in the immediately preceding group of leaves, the marginal zone portions of all the book leaves and the front cover being identical in size and shape between the lower ends of their sight apertures and the bottom edge of the book, the lower ends of all said sight apertures being in flush registry at a height portion completely encases the entire index side edge of the front cover and overlies all the sight apertures of the book leaves and front cover with a double thickness of the transparent sheet extending from the top to the bottom edges of the front cover. thereby providing reinforcement for the marginal edge zone portions of the front cover between the ends of its sight aperture and i the adjacent end edges of the cover.  
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