US2085845A - Printing apparatus - Google Patents

Description

July 6, 193'" u. M. BINKLEY PRINTING APPARATUS Filed Sept. 19, 1934 INVENTOR. URIAH M. BINKLEY MWLAAAAAMVA 'IIIIIIIIIIIIII'IIIIIIIIIIIA ATTORNEY.

Patented July 6, 1937 UNITED STATES PRINTING A'PPARATUS Uriah M. Binkley, Evanston, Ill., assignor, by

mesne assignments, to The Carborundum Company, Niagara Falls, N. Y., a corporation of Delaware Application September 19, 1934, Serial No. 744,707

3 Claims.

This invention relates to printing apparatus and more particularly to apparatus in which a tympan sheet and tympan roll are used, and has for its object the provision of improvements in the same whereby a more efficient and economical operation of the printing apparatus is obtained. Referring to the drawing which illustrates a suitable embodiment of the present invention,

Figure 1 is a section of a tympan roll with the make-ready and tympan sheet in combination thereon; and

Figure 2 is an enlarged section of a portion of one form of tympan sheet forming part of my invention.

As a result of my invention, a combination is effected comprising a tympan sheet and makeready covering the tympan roll, with an ink and oil barrier interposed therebetween. The use of this combination on printing apparatus where a tympan roll and tympan sheet are used insures a longer and more efficient use of the tympan sheet with a resultant reduction in operating costs. This is due to the fact that the barrier interposed between the make-ready and that of protectingthe delicately formed and expensive make-ready from the ink or oil spotted base of the tympan sheet, and that of enablin the absorbing qualities of the tympan sheet to 30 ink and oil to build up therein to the saturation point. I he greatly increased ink and oil storage capacity of the tympan sheet provided by this combination, together with the preservation of, the make-ready, materially lengthens the life of the tympan sheet and facilitates efllcient printing operations.

According to one modification of my invention,

a barrier 4 consisting of a very thin sheet of ink and oil resistant material such as pure cellulose, a cellulose ester, a resin of the thermoreversible or thermo-irreversible types, a metal foil such as aluminum, copper, zinc or similar foils, or the like, is adhesively attached to one 45 surface of a web of fabric 5. For this purpose various suitable adhesives or cements may be used, although in cases where the barrier is composed of material having self-binding properties, no auxiliary adhesive is required. 50 The opposite side of the .fabric 5 is then given a coating of adhesive such as glue, to which is applied by any method known in the art, a coating of granular material 6, such as silicon carbide, emergy, etc. Granular material of various 5 grits are used, and in this particular combinathe tympan sheet performs a dual function,--

be used to their fullest capacity bycausing the tion of fabric and barrier, I am enabled to successfully employ a very fine grit of the approximate size of .002 inch on a fabric ranging from .010 inch to .015 inch. To secure an exceptionally high grade of printing, it is desir able to have a substantially smooth and hard surface on the tympan sheet in order that there will be no perceptible roughness or pattern on the half-tones that are printed opposite the tympan sheet. I find that such a surface on the tympan sheet may be obtained by passing the granular coated sheet between press rolls by means of which the outstanding particles are fractured or broken off to the level of the majority of the granules. The supporting points do not rise above a predetermined level and lie substantially in the same plane, thus providing the desired smooth, hard surface.

The tympan sheet 5 with the barrier 4 adhesively attached thereto is then placed in position on the make-ready 3, which covers the tympan roll 2, with the barrier 4 in contact with the make-ready 3. By means of adjustable clamps I and 8, the combination sheet is clamped into firm engagement with the make-ready 3.

In the manufacture of a tympan sheet with the barrier united thereto, many variations in the above procedure may be made when found expedient to do so. For example, instead of applying the granular material subsequent to the formation of the combination sheet, one surfacepf the fabric is first coated with granular materialand to the uncoated side of the fabric 5 is attached the barrier 4 by any suitable adhesive. Also, in some types of printing, it is preferred to use the ordinary ink and oil resistant paper commonly known in the trade as tympan paper. When such type of paper is used, the step of applying granular material to the top surface thereof is omitted and the tympan paper is attached to the barrier 4 in the same manner as hereinabove described.

According to another modification of my invention, a barrier 4 of pure cellulose or the like is placed upon the make-ready 3 covering the tympan roll 2 and clamped into position by means of the adjustable clamps I and 8. The fabric 5, which may or may not be coated on one side with granular material, is then placed upon the barrier 4 and likewise clamped firmly into engagement with the barrier 4 and the make-ready 3. If the fabric has been previously coated on one surface with granular material, it is so positioned on the barrier 4 that the uncoated surface thereof contacts with the barrier.

In some cases, and particularly when very fine grit is used and when the granular particles have been fractured, it is desirable to flex the completed tympan sheet in order that the adhesive may be 5 uniformly cracked to allow the ink from the print and oil from the oil-wipe to flow down these cracks into the reservoir formed by the grain, glue, and paper or cloth backing, andthus leave the surface of the sheet free of all such accumulation that tends to occur otherwise. Although a limited amount of flexing occurs during the use of the tympan sheet on the tympan roll, I prefer to flex the sheet before the application of the tympan sheet to the make-ready by drawing the sheet over a bar of rectangular or other section that presents a suitable sharp corner to the backing.

The present invention overcomes the numerous disadvantages experienced with the tympan sheets heretofore used, in that storage space is here provided for the ink and oil, limited only by the ultimate capacity of the body of the tympan sheet. The ordinary ink and oil resistant paper used as tympan sheets has no ink capacity whatsoever and the ink and oil is customarily removed from the surface by means of an oil wipe. The capacity of the ordinary granular coated tympan sheets is practically negligible, consisting merely in the very small spaces between the gran ules. Such being the case, it has been necessary to use a coarse grit of grain, although it has been known that exceptionally good results in printing are possible only with fine grits or grits that have been broken down to present as nearly a flat surface as possible. It has been found heretofore that the adhesive of the usual tympan sheets breaks and forms cracks through which the accumulated ink and oil on the top surface of the sheet readily seeps to the make-ready. This seepage to the make-ready renders the tympan sheetuseless as the expense involved in the preparation of the make-ready necessitates that extreme care be taken. to prevent it from being ruined by ink deposits prior to the completion of the particular run of printing for which it was designed. In addition to the cracks formed by flexure of the sheets, high spots on the type puncture the sheetsand give further opportunity for the ink and oil to reach the makeready. In many cases, such punctures occur prior to the formation of cracks and although there are but few spots of ink seepage, the tympan sheet must be discarded immediately to safeguard the preservation of the make-ready.

The provision of an ink and oil resistant barrier interposed between the tympan sheet and the make-ready prevents any ink and oil from finding access to, .and subsequently-ruining the makeready. It further causes the ink and oil to build up in the body of the tympan sheet and to use the no absorbing qualities of the tympan sheet to their said granular coated sheet.

fullest capacity. As a result, the life of the tym pan sheet is lengthened in use from the period when a few spots of ink or oil reaches its base to the period when the entire body is completely saturated with ink or oil. In actual use of this invention in printing apparatus, I have found that the usable life of the tympan sheet is increased from 30% to 40% over the tympan sheets now commonly used.

Furthermore, with the barrier and tympan sheet combination of this invention, the heretofore undesirable cracking and puncturing of the tympan sheet is found to be an advantage, rather than a disadvantage, in securing clean printing. The cracks and punctures act to drain off the ink and oil on the top surface of the tympan sheet and especially prevent the building up of ink or oil between and above very fine grits or upon the substantially flat surface obtained by the fracture of the grits. It is possible, therefore, to use very fine grits upon granular coated tympan sheets which enables the printer to secure a much higher grade of printing on the finished product.

In addition to the above enumerated advantages secured through the use of a barrier and tympan sheet combination, the use of a metal foil as a barrier acts to bridge over any imperfections that may occur in the make-ready; It further prevents protruding type, caused by unevenness in the plate, from puncturing the tympan sheet and causing permanent marks in the makeready.

Having thus described my invention, what I claim is:

1. In a printing apparatus, the combination consisting of a tympan roll, a make-ready superimposed upon and encircling said tympan'roll, a granular coated ink-absorbent sheet encasing the tympan roll and make-ready, and an ink barrier interposed betweensaid make-ready and granular coated sheet, and united to the back of said granular coated sheet.

2. In a printing apparatus, the combination consisting of a tympan roll, a make-ready superimposed upon and encircling said tympan roll, a granular coated ink-absorbent sheet encasing the tympan roll and make-ready, and a layer of inkresistant cellulosic material interposed between said make-ready and granular coated sheet, and

united to the back of said granular coated sheet.

3. In a printing apparatus, the combination consisting of a tympan roll, a make-ready superimposed upon and encircling said tympan roll, a granular coated ink-absorbent sheet encasing the tympan roll and make-ready, and a layer of metal foil interposed between said make-ready and granular sheet, and united to.. the backof.

mum mm.

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