US781935A - Leaf for books. - Google Patents

Description

No. 781,935. PATENTBD FEB. 7, 1905. L. CLARK.

LEAP FOR BOOKS.

APPLIOATIOH IILBD 110mm, 190a.

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No. 781,935. Patented February 7, 1905.

UNTTED STATES PATENT EEicE.

LINCOLN CLARK, OF CHICAGO, ILLINOIS, ASSIGNOH OF 'IWVO IIIIRDS TO W. GIFFORI) JONES AND HARRY S. JONES, OF CHICAGO, ILLINOIS.

LEAF FOR BOOKS.

SPECIFICATION forming part of Letters Patent No. 781,935, dated February 7, 1905.

Application filed November I4, 1903. Serial No. 181,199.

if y and varying the place of curvature by rela Be it known that I, Lrxoonx CLARK, a cititive movement of the parts of the paper to zen of the United States, residing at Chicago, weaken or fracture the sizing coatingthroughin the county of Cook and State of Illinois, out the band portion (1 defined by said dotted haveinvented a new and useful Improved Leaf lines. This flexing operation may be repeatfor Books. of which the followingis a specilied as often as necessary; but ordinarily the cation. desired result may be obtained by folding the My invention relates to improvements in paper to curve the same about an almost inthe sized-paper sheets forming the leaves of linitesimal radius and varying the place of to books, and more particularly those of loosecurvature until the desired area has been leaf ledger-s. treated and finally reversing the direction of It is desirable to provide, particularly for curvature and varying the place of curvature accmmt-lmoks, leaves which will tend noruntil the same area has been flexed in the mally to lie flatwise upon each other when the opposite direction. In the flexing operation 1 books are open to present firm surfaces to the sufficient pressure is applied to bend the papen. and a common manner of forming such per closely upon itself, while the continuous 5 leaves is to cause an area or zone of each sheet change in the place of curvature prevents the adjacent to its binding edge to be more flexi- 1 paper from being sharply folded or creased. ble than the other parts of the sheet. Vari- The effect of the treatment is to thoroughly 2o ous methods have been employed for providfracture the sizing coatings of the paper along ing the said flexible zones or areas; but they almost infinitely close lines without injuring 7 all, so far as I am aware, involve treatments 5 the fiber of the paper, which commonly is of C or operations which are more laborious or exlinen. At the same time the sizing coatings pensive than is thought to be desirable and in are left in such a smooth and complete condithose constructions which have proven the tion as to enable the surfaces to be written most practical heretofore tend materially to upon freely with ink. Thus, it will be under weaken the paper along well-defined lines, stood, the tenacity and smoothness of the wherelrv, particularly after frequent turning treated section of the leaf are unimpaired, of the leaves, and consequent flexing along while the flexibility is increased greatly. If

30 fhoselines, theleaves tend to become too weak desired, the paper may be bent over a wire thereat to withstand ordinary handling. or strip presenting a blunt rounded edge and 30 My object is to provide a new and improved then drawn across the same to flex the paper method of rendering flexible without materiwithout creasing it, while fracturing or weakally weakening areas or zones on sized-paper ening, the sizing coatings to decrease the resheets; and my invention consists in the silience thereof. In the flexingoperation unimethod I employ and also in the improved formity of curvature coupled with continuity 5 leaves produced by the said method. of change of place of curvature is desirable In the accompanying drawings, Figure I is to avoid the productionofcreases,which would a plan view of a loose leaf provided in accordunduly weaken the sheet along definite lines.

4 ance with my invention; Fig. 2, an edge view Rendering the paper highly flexible at the of the same, and Fig. 3 also an edge viewshow section operated upon in the mannerdescribed 9 ing the leaf bent under its own weight at the does not materially change the appearance of zone of greatest flexibility. the paper, and the desired result is attained A represents a sheet of calendered paper without either thickening or thinning the 45 having a binding-edge portion a. In carrypaper at said section. Moreover, great uniing out my invention I subject the leaf beformity of flexibility results from the imtween, for example, the dotted lines 1/ to it proved treatment, and tests have shown that mechanical flexing operation which consists, the tearingstrength of the paper is practically preferably, in turning the paper upon itself unimpaired, attributable, as suggested above,

to the preservation of the fiber of the paper and the absence of definite lines of weakening. As the tenacity of the paper is practically unimpaired, the treated section may extend from the extreme top to the bottom edge of the leaf.

In carrying out my method any kind of ledger-paper may be provided with a bending zone without regard to the thickness of the paper, unevennesses in the surface, or the state of the paper with regard to dryness.

Changes within the spirit of my invention are contemplated. Hence no undue limitation should be understood from the foregoing detailed description.

What I regard as new, and desire to secure by Letters Patent, is

1. The method of treating sized paper to render it more flexible over alimited bending area, which consists in minutely fracturing the sizing coating by flexing the sheet uniformly throughout a band portion only without scoring or creasing, whereby the fiber of said band portion is left uninjured, definite lines of weakness avoided therein and the surfaces thereof preserved for writing purposes, the remainder of the paper being left unchanged in all its qualities, for the purpose set forth.

2. The method of treating sized paper to render it more flexible over a limited bending area, which consists in minutely fracturing the sizing coating by subjecting the leaf to a flexing operation throughout a limited area only and varying the place of curvature uniformly throughout said area, without scoring or creasing, whereby the fiber of the paper at said area is left uninjured, definite lines of Weakness thereat avoided and the surfaces thereof preserved for writing purposes, the remainder of the paper being left unchanged in all its qualities, for the purpose set forth.

.3. The method of treating sized paper to render it more flexible over a limited bending area, which consists in minutely fracturing the sizing coating by subjecting the leaf to a flexing operation throughout a limited area only and varying the place of curvature uniformly throughout said area, and then reversing the direction of curvature and varying the place of curvature uniformly throughout said area, without creasing or scoring, whereby the fiber of the paper at said area is left uninjured, definite lines of weakness thereat avoided and thesurfaces thereof preserved for writing purposes, the remainder of the paper being left unchanged in all its qualities for the purpose set forth.

4:. As a new article of manufacture, a leaf ofsized book-paper having a transverse band portion adjacent to its binding margin with the sizing coatings minutely fractured uniformly throughout said band portion, said band portion retaining its fiber and surfaces practically unimpaired and possessing greatlyincreased flexibility, the remainder of the paper retaining its original qualities, substantially as and for the purpose set forth.

5. The method of treating a leaf of sized book-paper, to provide a zone of increased flexibility, which consists in minutely fracturing the sizing coatings by subjecting a band portion parallel with and adjacent to the binding edge of the leaf to a flexing operation and varying the place of curvature uniformly parallel with said binding edge throughout said band portion, and then reversing the direction of curvature and varying the place of curvature uniformly throughout said band portion, whereby the fiber at said band portion is left uninjured and definite lines of Weakness avoided, the flexibility thereat increased, and the surfaces thereof preserved for writing purposes, the remainder of the leaf being left unchanged in all its qualities, substantially as and for the purpose set forth.

LIN ()OLN CLARK.

In presence of- WALTER N. WINBERG, F. M. VVIRTZ.

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