NVENTOR

1

".This invention -relates -to a '-backing *sheet’=hav,;ing '.near one ',8X'ld ~‘thereof ta row of evenly spaced substantiallyrectangular slotseach pair -of which at theinner ends ‘thereof communicates iw‘ith»opposite upper ends of a depending arcuate ~inc"is'ion ..eX.tend‘ingi'through*a_t least 180° to define a~n*'in,te_gral‘ton_gue which normally lies-inthe plane of /the sheet. The several-tongues thus formed are aligned across" thebacking sheetnear its top-and are ,a.dap'ted ‘to flex cdivergingly a sufficient illsgtanceto receive the"edges"of;an-assembly of paper -sheets to ‘be aligned and clamped in place ~~to facilitate and assure the;retentive positioning of all such sheets preliminary to -and during the Qperation of makingimpressions thereon.

A backing sheet of "this character is advantageous in that zit facilitates the "retention and prnper alignment of .a number of sheets which linclude interleaved record and carbon sheets. Such a backing sheet is flexible so as to bend when passing around the platen of a typewriter or other recording machine, and is desirably resilient to some .degree as well. The tongues also are bendable outwardly from the normal fiat ‘plane-o‘f~the-backing sheet so as to exert a light clamping pressure upon the paper sheet assembly when Jrested upon the backing sheet. However, the upper edge portion of the paper sheet assembly is deflected at points adjacent opposite sides of theitongues, and 'these*bends which;ooc11r at spaced points crosswise of the paper sheet assembly take on the form of bulges which may be detrimental to the sheets in more ways than one. At each point of bulge the paper assembly is subjected to a crimping action which tends to pinch and squeeze each of the paper sheets thereby to produce a puckering thereof, and also to transfer a smudge from a sheet that is carbon-coated to an adjacent record sheet. These are some of the deficiencies which are inherent in backing sheets as heretofore made.

It is an object of this invention to eliminate all such shortcomings with the present backing sheet whereon a paper sheet assembly may be operatively positioned. I accomplish this by dual means, viz., the form and location of the rectangular slots which together with certain depending incisions define the tongues and also fix the spacing thereof with respect to each other. As a result, an assembly of record and carbon sheets may be inserted beneath the clamping tongues for retentive positioning thereby with only a minimum of deflection on the part of the tongues and on the part of the sheets which are held thereby. All undesirable bulging, with con

‘5

10

15

20

2;“:

30

=2 seguent transverse contraction of lthe sheet, is ithereby effectively avoided. I

A suggestive embodiment of =m-y invention -is "illustrated ' in the ~acc0mpanying drawing wherein:

,Fi_gm-_e ~1 is a view einperspective of the back?ing "sheet per se;

‘Figs. '2 and 13 are ‘enlarged fragmentary <sectional views, taken on lines '~2—2 and 3-—‘3 oT‘?Eig. ‘1,,_showing-an‘-assembly of paper =s'heets~operatively positioned on the ‘backing -sheet; and

Fig. "4 is;a fragmentary,-_»plan -view-of one upper corner‘ portion of "the present‘ -backing sheet.

The present backing sheet ~S is of -a size for cooperation ,w,ith:a-n-assembly of -record and~carbon "sheets A ‘which are to ‘be operated upon lby a printing or rrecordingmachine, such as Ia‘ typewriter. As illustratedin ‘Figs. la-nd 3, the!bac'7king sheet S is_provided‘nearits upper -endvwith a row of _aligned.'base-slots 10, all alike, and (each of substantially rectangular contour -with its longer ;dimensio_n crosswise of -the isheet. The upper -and "lower edges of these ‘base ‘slots are coincident’~with the broken ‘lines »w—~:r and ’y—~jl/. The slots are-also even in ‘number and spacing.

"The inner "end of "each base slot at c the end sof

the"rowjjoins"with one ‘end of a relatively narrow incision 'l~| -in the-form of -a -depending ‘loop. As shown, ‘each such incision is arcuate'with»‘i-ts center {located on the line ~y—-Ty. The outer iedge of thisincisionlterminates on-theliney-—y whereas its inner edge continues on up to terminate with the line a:—a: and constitute the inner edges for the associated slots. Each pair of base slots I0 is similarly joined at its inner ends to a depending arcuate incision ll thereby to form in each case a tongue T between which are intervening web portions I2. From Fig. 4 it will be apparent that the width of each tongue crosswise of the sheet is greater than is its length, and measured from its center point c the tongue length is one-half of its width.

The backing sheet is desirably formed from some paper or composition material that is both flexible and resilient. The sheet is required to bend in use, and the tongues should normally remain in a plane which is coincident with that of the backing sheet. As illustrated clearly in Fig. 1, the number of base slots is eight, making four tongues therebetween, this being a convenient and satisfactory arrangement for a backing sheet having a width of approximately 8%". The spacing of the outermost base slots from the proximate sides of the sheet is desirably the same as that existing between the slots them

3

selves, thereby fixing the position of the outermost tongues inwardly from the sheet sides by a distance which is approximately the same as the spacing between the tongues themselves. When inserting a sheet assembly A in operative position upon the present backing sheet, it will be convenient to angle the several tongues upwardly in relation to the normal plane of the sheet, by flexing back its upper edge portion. Any such position of the tongues is, of course, abnormal since they tend to return to a coplanar position relative to the backing sheet, and will do so whenever permitted to restore themselves to normal position. i When the tongue are angularly raised, as shown in Fig. 2, the insertion of an assembly A of record and carbon sheets is facilitated. When properly inserted, the several paper and carbon sheets comprised in the assembly will be correctly aligned with respect to each other, and will also be clamped retentively beneath the several tongues. Inasmuch as the sheet assembly A forces the tongues T to remain flexed upwardly out of the plane of the backing sheet (see Figs. 2 and 3), the portions of the backing sheet along the line a:—:c between these tongues, i. e., the webs I2 , will be subjected to an opposite pressure tending to flex the webs downwardly between the base slots Ill. These webs are of a length the same as the width of the tongues along the line rr-0: so as to resist equally therewith the opposite pressures tending to produce opposite deflections thereof from the normal plane of the backing sheet (see Fig. 3). These base slots I0 are of substantial size and slightly elongated transversely of the backing sheet, so that the assembled record and carbon sheets are required to bridge a relatively wide span when passing from a plane below the tongues to one upon the sheet. As a result, the record and carbon sheets are bulged only gently and slightly, and evenly in both directions. The deflections of the assembly of record and carbon sheets along their clamped end portions, in a plane normal to that of the backing sheet, produce a gently undulating contour, as suggested in Fig. 3. There is no pinching or squeezing of the sheets such as to impair their smoothness, and also to contract their overall width, nor is there any tendency for the carbon sheets to smudge the record sheets in this elongated area of undulation.

4

I claim:

1. A backing sheet of the kind described formed of a flexible resilient material having near its upper edge and parallel therewith a row of rectangular slots, even in number and spacing and each elongated lengthwise of the row, and each pair of slots, commencinging with the two at one end of the row, being joined at its inner end with two opposite ends of a depending relatively narrow incision in the form of a loop thereby to define a tongue evenly spaced from the adjacent tongues, the length of each tongue being less than its width at its point of connection with the backing sheet and its width at such point approximating that of each web extending between adjacent pairs of the base slots.

2. A backing sheet of the kind described formed of a flexible resilient material having near its upper edge and parallel therewith a row of substantially rectangular slots, even in number and spacing and each elongated lengthwise of the row with opposite horizontal edges coincident with upper and lower parallel lines, and each pair of slots, commencing with the two at one end of the row, being joined at its inner ends with opposite ends of a depending relatively narrow arcuate incision extending through a full 180° and having its center located midway of the associated slots and substantially on the lower of the two parallel lines coincident with their horizontal edges whereby the outer edge of the arcuate incision terminates at its point of juncture with the lower edge of each slot and the inner edge of the incision continues upwardly therebeyond to join with the upper edge of each slot and to constitute therefor its inner edge, thereby to define a tongue evenly spaced from the adjacent tongues and joined to the backing sheet along a line coincident with, and of the same length as, the webs between adjacent pair of slots.

FRANK S. COOPER.

REFERENCES CITED

The following references are of record in the file of this patent:

UNITED STATES PATENTS

Number Name Date 1,999,015 Cooper _________ __ Apr. 23, 1935 2,095,792 Cooper __________ __ Oct. 12, 1937