US1453384A - Method of making printing-plate blanks and product thereof - Google Patents

Description

May 1, 1923.'

1,453,384 J. s. DUNCAN METHOD OF MAKING PRINTING PLATE BLANKS AND PRODUCT THEREOF Filed March 15 1922 Patented May 1, 1923.

JOSEPH S. DUNCAN, OIE CHICAGO, ILLINOIS.

METHOD OF MAKING PRINTING-PLATE BLANKS AND' PRODUCT THEREOF.

Application filed March 13,1922. Serial No. 543,161.

T all whom it may concern: 7

Be it known that I, JOSEPH S. DUNCAN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Methods of Making Printing-Plate Blanks and Product Thereof, of which the following is a specification. This invention relates to printing plates of that kind which comprises a thin metal plate having type characters stamped in relief thereon. Such plates are prepared from blanks which are cut from sheets or strips. The type characters are stamped in relief on the blank plates in suitable machines which operate to stamp the characters to a standard and uniform height. But some difficulty in'manufacture has resulted from variations in the thickness of the strip or sheet and consequently in the blanks and since the type characters are of a standard and uniform height on, every blank it may result that the impression taken from a printing plate made from .a blank of less than the predetermined thickness will be too light or indistinct; or an equally unsatisfactory impression may result from a printing plate made from a blank which varies in thickness from end to end or from side edge to side edge.

Since it seems to be impossible to obtain strips or sheets of a standard uniform thickness I have found it necessary to process the blanks so that the printing face of the type characters of every plate will always be in a plane parallel with and uniformly spaced from the plane of the back supporting face of the plate and thus insure a uniform impression of predetermined character from all printing plates. 7

This being the broad and fundamental object of the invention, I also aim to accomplish the aforesaid desirable results in a simple and effective manner which will not involve any changein the present method and means of cutting the blanks, stamping the characters thereon, or using the printing'plates.

In the accompanying drawings illustrating a selected embodiment of the invention produced by a method which. I have found to be satisfactory in practice Fig. 1 is a plan View of one form of blank which may be used and Fig. 2 is a side view of the same blank; I Fig. 3 is a plan view showing the back of the blank with projections thereon and. Fig. 4 is an edge view of thesame blank;

Fig. 5 is a diagrammatic view showing a pair of rolls with the blanks of Figs.o3 and at passed part way therethrough; I Fig. 6 is an end view of one plate and Fig. 7 is an edge view, of another' plate, both embodying my invention and showing it meeting different conditions. 5 Referring to the drawings, 8 designates a blank which may be of any suitable form differing from that shown, and which is adapted 'to receive type characters 9 stamped in relief thereon in a suitable machine. This 7 blank is cut from a strip or sheet. of metal which will have a gauge or thickness as uniformly standard as present commercial manufacture produces but which, in fact is known to vary more or less in thickness. ,Itwill be understood, of course, that if the blank departs too far from a predetermined standard and exceeds predetermined limits it will be rejected as unfit for making a. printing plate even with the present invention; but if the blank departs from the standard thickness and varies only within certain predetermined limits it can be used satisfactorily in the production of a printing plate according'to present methods provided it is first processed in accordance with. my invention. The predetermined limits referred to will depend upon the character of the metal, the height and character of the type characters to be stamped and other conditions which will be apparent to those skilled in the art, and since these limits may vary with the conditions I will not attempt to specify any particular limits. The blank 8 is stamped to provide a plu- 95 rality of projections 10 on the back thereof. These project-ions may vary in size, shape, location and arrangement but I havefound it desirable to provide narrow elongated projections arranged in lines extending lengthwise of the blank and of uniform height, the lines of projections being located adjacent the side edges of the blank and also between the spaces where lines of type are to be stamped, thus providing a. line of. projections at each side of each line of type on the plate.

After the projections are thus formed on the blank, by any suitable stamping means and according to any suitable metal, the blank is rolled to a uniform thickness by passing it between a pair of rolls ll, 11, or in any other suitable way. The projections 10 are of uniform height on the back of the blank regardless of the uniformity or lack of uniformity of thickness of the blank and the purpose of the rolling operation is to reduce the height of the projections where the thickness of the blank including the projections is greater than the predetermined standard. If we assume that the thickness of the plate including the projections, that is to say between the plane of the face of the plate and the plane of the face of the projections is greater than the standard thickness desired, all of the projections will be reduced by the rolling operation until the thickness conforms with the standard; if one part. of the blank is thicker than the remainder of the blank the projections of the thick part Will be reduced more than the projections of the thin part if the latter are reduced at all. The projections may be completely reduced to form a smooth back for the blank, substantially as it was originally, or all of the projections may stand up more or less on the back, or the height of the projections may vary throughout the back, these different conditions depending upon the original thickness of the blank as will be readily understood.

After the blank has thus been formed to a standard uniform thickness between the plane of its front face and the plane of its back the type characters 9 are stamped up thereon between the lines of projections in a. suitable machine.

My invention provides a method and means for insuring standard uniform thickness in blanks for making printing plates and it' will be apparent that plat-es made from blanks processed in this manner will be uniform in height and under the same conditions will give uniform impressions.

I do not limit myself to the size, shape, form, or arrangement of the projections be cause they may be varied as desired to suit different conditions so long as they are adapted to perform the function and produce the result hereinbefore set forth; nor do I limit the invention to the particular means for processing the blank in the steps hereinbefore described since it will be apparent to those skilled in the art that many different means for accomplishing these resuits may be employed; and I reserve the right to make all changes in practicing my invention which fairly fall within the scope of the following claims.

I claim:

1. A printing plate blank of uniform thickness and consisting of a strip having projections on one face thereof of a height to compensate for any deficiency in the thickness of the strip.

2. A printing plate blank of uniform thickness and consisting of a metal strip having projections on one face thereof to make up any deficiency in the thickness of the strip.

3. A printing plate blank of uniform thickness and consisting of a strip having independent projections distributed over one face thereof to make up any deficiency in the thickness of the strip.

4. A blank for a printing plate consisting of a strip having rows of projections on one face thereof to make up any deficiency in the thickness of the strip.

5. A printing plate blank of uniform thickness consisting of a strip having independent projections arranged in rows on one face thereof to make up any deficiency in the thickness of the strip.

6. A blank for a printing plate consisting of a strip having rows of projections located on one face thereof at opposite sides of the space where the type characters are tobe stamped and of a height to compensate for any deficiency in the thickness of the strip.

7. A blank for a printing plate consistingof a strip having rows of projections-located on opposite sides of each space Where type characters are to be stamped and of a height to compensate for any deficiency in the thickness of the strip.

8. The herein-described method of making a blank for a printing plate which consists in cutting a' strip to the size of the plate, stamping projections on one face thereof,a11d then reducing said projections where required to produce a blank of uniform thickness. V

9. The herein-described method of making a blank for a printing plate which consists in cutting a strip to the size of the plate, stamping projections on one face thereof, and then passing the blank between rolls to reduce said projections Where required to produce a blank of uniform thickness.

10. The herein-described method of making a blank for a printing plate which con sists in cutting a strip to the sizeof the plate, stamping projections in spaced relation on' one face thereof, and then reducing said projections Where required to produce a blank of uniform thickness.

11. The herein-described methodof making a printing plate which consists in cutting a strip to the size of the plate, stamping projections on one face thereof, then reting a strip to the size of the plate, stamping ducing said projections Where required to projections in rows on-one facethereof, then I produce a blank of uniform thickness, and reducing said projections Where required to then stamping printing characters on the produce a blank of uniform thickness, and

5 other face of the blank apart from said prothe'n stamping printing characters on the jections. other face of the blank in between the rows 12. The herein-described method of makof projections.

ing a printing plate which consists in cut- JOSEPH S. DUNCAN.

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