US3307478A - Imprinting carbon-master set - Google Patents

Description

March 7, 1967 J. KEEN IMPRINTING CARBON-MASTER SET Filed 00*: 11, 1965 STATE ADDIQESS A B c co. STREET CITY FIG. 3

FIG 2 INVENTOR. W352 flz-A (commonly known as 3,307,478 IMPRINTIN G CARBON-MASTER SET Joseph Keen, Bronx, N.Y., assignor to Repeat-O-Type Stencil Manufacturing Company, Inc., Wayne, NJ., a corporation of New York I Filed Oct. 11, 1965, Ser. No. 494,771 2 Claims. (Cl. 101--149.4)-

facing relation to each other such that upon the application of printing on the front face of the master sheet a carbon mirror image thereof is reproduced on the rear face of this master. This rear face of the master with said carbon reproduction of text and the like is employed, in a well understood and known manner, as an imprinting master.

Consistent with the foregoing functioning of carbonmaster imprinting sets, it is broadly an object of the present invention to provide an improved set wherein the reproduction of inadvertent markings on the master sheet is minimized Without interfering with the effective and efficient reproduction of intended text or markings on said master sheet rear surface. Specifically, it is an object to provide a carbon-master set wherein heavy pressure printing is effective in preparing said master sheet for imprinting, but light pressure marking such as generally characterizes inadvertent marking of the master sheet is not reproduced on the master sheet rear surface.

The above brief description, as well as further objects, features and advantages of the present invention, 'will be more fully appreciated by reference to the following detailed description of a presently preferred, but nonetheless illustrative embodiment in accordance with the present invention, when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a plan view of an imprinting carbon-master sheet set demonstrating features of the present invention;

FIG. 2 is a fragmentary plan view of the interleaf sheet of said set which illustrates in detail the construction and nature of such interleaf sheet; and

FIG. 3 is a sectional view, on a greatly enlarged scale, of the component sheets of said imprinting carbon-master sheet set.

Reference is now made to the drawings wherein there is shown an integrated imprinting sheet arrangement 10 which is substantially identical to currently available socalled spirit carbon master sets with the exception that there is included an improvement in the form of a novel interleaf sheet 12. The integrated arrangement of sheets or set 10 is of the type which is employed with so-called ditto duplicating machines such as is available from Ditto, Inc., of Chicago, Illinois, as well as being employed in other and similar type of duplicating equipment. Consistent with the contemplated use in such duplicating equipment, the set 10 includes a master sheet 14 having a front and rear face 14a, 14b respectively, Which is placed in condition to be utilized as an imprinting master. This is accomplished by direct printing of words and other materials, herein collectively designated 16, on the front face 14a of the master sheet 14, as well as by direct typing of material 18 on this master sheet surface. In both instances, this results in the printed or typed material being reproduced backward, as at 20, on the rear sheet surface 1412. As is generally understood, the reproduc- United States Patent f 3,307,478 Patented Mar. 7, 1967 tion of the printing 20 is achieved with so-called spirit blue dye, an alcohol-soluble triphenylmethane dye commonly used in the manufacture of carbon paper and readily transferable to other paper surfaces by being placed against these paper surfaces and subjected to pressure.

As is further generally the practice, this dye which produces the printing 20 is provided as a surface coating 22 on a backing sheet 24 which is connected along an upper edge 26 to the master sheet 14. Thus, the surface coating 22 of this transfer dye and the imprinting surface 14b of the master sheet 14 are in facing relationship to each other in the conventional arrangement of the set 10. In accordance with the present invention an interleaf sheet 12 formed of a tissue paper commonly known as mimeograph stencil tissue and commercially available from numerous sources (e.g. C. H. Dexter & Sons of Windsor Locks, Conn.) is employed in an interposed position between the master sheet surface 14b and transfer dye coating 22 in order to maintain the surface 14b clear of inadvertent markings, all as will be subsequently explained in greater detail. The material of construction for the interleaf sheet 12 is also sometimes known by the Japanese designation of Yoshino paper and is commonly used in the manufacture of porous tea bags. For present purposes it is to be understood that as used herein and as used in the claims hereof the interleaf sheet 12 is socalled mimeograph stencil tissue formed from a material of construction, such as a blend of manila hemp fibers and coniferous wood fibers of a basis weight of approximately 6.60 lbs. (24 x 36480) and which is characterized by being of a highly absorbent nature. This absorbent character may result from the construction of the paper with said hemp and coniferous individual fibers 28 which are well known to be of an absorbent character. In practice when printing or typing 16, 18 is produced under pressure on the master sheet front surface 14a, this results in the application of a localized pressure in the form or shape of the letters of the printed text being applied through the master sheet 14 and through the fibrous body 28 of the interleaf sheet 12. against the transfer dye surface coating 22 of the backing sheet 24. Under these circumstances, the absorbent interleaf sheet 12 functions to accept the transfer dye from the surface coating 22 and transmit this dye, as by soaking, through the fibrous body 28 thereof through to the surface which is in physical contact with the master sheet surface 14b. Thus, the transmitted transfer dye is applied as printing 20 to the surface 141; of the master sheet 14. In this manner a mirror image of printing 18 is reproduced as backward printing 20 on the surface 14b of the master sheet 14 even though the interleaf sheet 12 is never removed from an interposed position between the master sheet surface 14b and transfer dye surface coating 22.

From the foregoing it should be appreciated that the absorbent interleaf sheet 12 is effective to prevent inadvertent dye transfer from the surface coating 22 to the master sheet surface 1415 while not interfering with or preventing intended dye transfer. Such intended dye transfer which results from heavy pressure printing 18 being applied on the front surface 14:: of said master sheet 14 is effectively applied right through the interleaf sheet 12 while inadvertent light pressure marking on the master sheet surface 14a is not. The use of said absorbent interleaf sheet 12 is thus an improvement over the use of a generally non-absorbent interleaf sheet of prior art imprinting sets. Such prior art interleaf sheets as are now relied on to protect the master sheet surface 14b require removal from this protecting position during the application of printing or typing 16, 18 in order to permit the printing 20 to be effectively reproduced on the master sheet surface 14b. If numerous printing or typing operations are performed on the set 10 in preparing the master sheet 14 for imprinting, as is generally the case, in each instance the prior art non-absorbent interleaf sheet must be removed prior to such printing and then placed back in position following this printing operation. In contrast, the absorbent interleaf sheet 12 of the present invention is left in position at all times between the master sheet 14 and backing sheet 24.

A latitude of modification, change and substitution is intended in the foregoing disclosure and in some instances some features of the invention will be employed Without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein.

What is claimed is:

1. A method of preparing a master sheet for imprinting, said master sheet being included in an arrangement of sheet material; said arrangement including in addition to said master sheet a backing sheet having a coating of a transfer dye in facing relation to said master sheet and an interleat mimeograph stencil tissue sheet of an absorbent character in an interposed position between said master sheet and said coated backing sheet, said method of preparing said master sheet for imprinting comprising the steps of printing on said master sheet with sufficient pressure and causing the transfer dye, in response to said pressure, to soak through said interleaf mimeograph stencil tissue sheet onto said master sheet.

2. An improved method of preparing a master sheet for imprinting as defined in claim 1 wherein said transfer dye on said backing sheet is spirit blue.

References Cited by the Examiner UNITED STATES PATENTS 2,372,918 4/1945 Vickery M 101-149.40 X

ROBERT E. PULFREY, Primary Examiner.

I. A; BELL, Assistant Examiner.

Claims (1)

1. A METHOD OF PREPARING A MASTER SHEET FOR IMPRINTING, SAID MASTER SHEET BEING INCLUDED IN AN ARRANGEMENT OF SHEET MATERIAL; SAID ARRANGEMENT INCLUDING IN ADDITION TO SAID MASTER SHEET A BACKING SHEET HAVING A COATING OF A TRANSFER DYE IN FACING RELATION TO SAID MASTER SHEET AND AN INTERLEAF MIMEOGRAPH STENCIL TISSUE SHEET OF AN ABSORBENT CHARACTER IN AN INTERPOSED POSITION BETWEEN SAID MASTER SHEET AND SAID COATED BACKING SHEET, SAID METHOD OF PREPARING SAID MASTER SHEET FOR IMPRINTING COMPRISING THE STEPS OF PRINTING ON SAID MASTER SHEET WITH SUFFICIENT PRESSURE AND CAUSING THE TRANSFER DYE, IN RESPONSE TO SAID PRESSURE, TO SOAK THROUGH SAID INTERLEAF MIMEOGRAPH STENCIL TISSUE SHEET ONTO SAID MASTER SHEET.

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