US1995973A - Printing cylinder - Google Patents

Description

March 2 6, 1935. ERICKSSON 1,9955973 PRINTING CYLINDER Filed Aug. 1, 1954 g vwa/wboo Em/Y Ericka: an

.r'atented Mar. 26, 1935 PATENT O-FFICE PRINTING CYLINDER Emil Erlcksson, Chicago, Ill., assignor to Standard Process Corporation, Chicago, 111., a corporation of Illinois Application August 1, 1934, Serial No. 737,984

9 Claims.

10 ably journalled in a printing press so as to bear on a sheet or web to transfer inked impressions thereto.

Prior to the present invention there have been three general types of printing cylinders having an external surface adapted to receive designs or other markings to be printed. These prior cylinders when used for intaglio printing have an external copper printing surface in which a designis engraved or etched to receive the ink. In manufacturing the first of these types, a heavy solid copper cylinder with a substantial wall thickness is formed and pressed on a tapered intagilo printing press mandrel by hydraulic pressure. The cylindrical interior of the copper is tapered to conform to the taper of the mandrel on which it is to be fitted.

The second of the prior types of printing cylinders comprises a coating of copper applied to a steel or iron core by a special method of electro-deposition. The thickness of electrolytically plated copper on these steel or iron cores in this second type of roll varies from one sixteenth to one eighth of an inch in thickness.

The third type of printing cylinder known for years prior to the printing cylinder disclosed and claimed herein comprises a seamless copper tube pressed over an iron or steel core. This third type of printing cylinder of the prior art is used only when cylinders of very large size are needed with economy as the main consideration and when the surface is to be photo-etched.

There are serious drawbacks to manufacturing the three prior types of printing cylinders briefly described above as well as numerous disadvantages attending their use.

In the first type of cylinder, where solid copper of substantial wall thickness is used and pressed onto a tapered mandrel, the solid copper shell is very expensive. Prior to the invention to be disclosed herein these were the only standard rolls known to the textile trade. In providing these cylinders with a design to be printed they are either photo-etched, hand engraved, pantographed or milled with the desired design. After the desired number of impressions have been made from the prepared surface of the roll, the design is turned or ground off and the surface of the roll is finished for another engraving. These turning, polishing, etching and printing operations are repeated, continually reducing the circumference of the printing cylinder, so that the diameter of the roll becomes too small for further use, leaving in some cases more than onehalf of the solid copper of the original roll that must be discarded, and which is worth only the price of scrap copper. It will be seen that the initial cost of the prior art cylinder of the first type is high, and also that its useful life is short and that the roll is wasteful of expensive material.

A disadvantage attending the use of the solid copper roll is that it very soon becomes distorted from its original cylindrical shape. This occurs as a result of repeatedly pressing the copper roll over the relatively hard steel mandrel, the inside diameter of the roll increasing with each pressing. After the inside diameter of the roll increases it will not stay securely in the same place on the mandrel requiring the use of cloth liners or shirts, as they are known to the trade, the cloth liners being wound around the mandrel to take up the increased inside diameter. With the terrific pressure applied by the hydraulic press it can readily be seen that the roll very soon gets out of true.

Another disadvantage encountered in using the solid copper roll is the existence on the surface of the roll of hard and soft spots. These hard and soft spots are the result of the many imperfections such as blowholes, etc., in the original ingot from which the roll is made by piercing the ingot and drawing it through a die. The hard and soft spots in the roll increase the difliculty of engraving the design on the roll and are particularly detrimental when the widely used photo-etching method is used to apply the design.

The second type of roll of the prior art which carries a plated layer of copper on its surface has one outstanding defect. If either hand engraving or milling of the design on the roll is used, the copper will come loose in spots from the roll. This is due to the actual stretching or moving of the plated copper covering by the constant tapping required in hand engraving, or the heavy pressure of the die used in milling. This is practically the only drawback to an electrolytically plated roll or cylinder.

The third type of prior art roll available for intaglio printing has so many disadvantages attached to its use that, as stated above, it has become almost obsolete except in the special case of photo-engraved rolls of large size. In the first place it is almost impossible to get a perfect metal to metal contact between the tube and the core by pressing the tube over the-core and therefore there is a constant danger of the tube loosening from pressure. Again, it has the same imperfection as to the hard and soft spots, or lack of uniformity in the copper itself, as the first type of roll above described. It has also the one shortcoming of the second type of .prior art roll, only to a greater extent, as the copper is not united to the core. I

To sum up the disadvantages of the prior art I printing cylinders and the diificulties attending their use, they are expensive to produce, the printing surface in all except the second type is not uniform and only one, namely the first which is the most expensive and wasteful of the three can be used when the design is to be applied by hand engraving or' milling. In none of these prior types of rolls is there any actual union between the copper and the base roll of iron or steel. In the second type of roll, namely that provided with an electroplated layer of copper, the copper layer is merely adherent to the base and will loosen under the circumstances named above, and will also tend to loosen due to the difference in coefficients of expansion between the steel core and the plated copper. Because of the lack of union between the copper and the base roll, the cylinders of the prior art become distorted in use and will not give perfect printed images.

Accordingly, no printingcylinder has heretofore been available which can be used regardless of which process is to be employed in applying the design or marking to be printed and which can be produced and used in any desired size.

By the present invention I provide a printing cylinder in which the outer metallic layer having properties which make it especially suitable for intaglio or typographical printing is integrally and therefore inseparably united to the base or cylindrical backing of stronger and cheaper metal. Printing cylinders constructed in accordance with this invention do not have any of the disadvantages mentioned above and may be made in any size having any desired length and diameter. These improved cylinders surmount the difiiculties mentioned above and have numerousadvantages not to be found in typographical and intaglio printing cylinders of the prior art. The cost of a finished cylinder embodying this invention will be considerably below the cost of any one of the three old types of roll of similar dimensions, and this improved cylinder despite its relatively low cost will be substantially perfect in every respect.

In addition to being applicable to the production of new printing cylinders, my invention is also applicable to the renewal of worn or used cylinders, either of the improved types herein disclosed, or of the prior. cylinders of the first type above mentioned.

Therefore it is a primary object of the present invention to provide a novel low cost and improved printing cylinder for use in intaglio and typographical printing processes, the improved cylinder comprising a base roll of ferrous or like relatively cheap metal having an integrally and permanently united layer.of a metal having properties necessary for use inthe particular printing process contemplated. I

Another object of the present invention is to provide a printing cylinder comprising a core of forged or cast steel .or other suitable metal welded to an outer layer of copper, an alloy of copper, or other suitable metals.

Still another object of the present invention is to provide a textile printing roll comprising a copper layer autogenously united to a base roll of ironor steel.

It is still another object of the present invention to provide a printing cylinder comprising a backing roll having a wall of substantially uniform thickness and formed so that it may be mounted on the shaft of a printing press or like machine, the said backing roll having a cast external layer of copper or a copper alloy or the like autogenously united thereto.

Still another object of the present invention is to provide *a typographical printing cylinder comprising a bronze, brass, zinc or like layer autogenously welded to a base roll of iron or steel.

Further objects of the invention will appear from the following detailed disclosure of illustrative embodiments thereof and from the scope of the appended claims.

Referring to the drawing:

Figure 1 is sectional elevation through a form of printing cylinder embodying the present invention.

Figure 2 is an end view of the cylinder of Figure 1, the supporting shaft being omitted for the sake of clearness of illustration. Y

Figure 3 is a view similar to Figure 1 of another form of printing cylinder embodying the present invention.

Fig. 4 is a sectional View taken along line 4-4 of Figure 3.

I have chosen only two embodiments for the purpose of illustrating my invention, but it is to be understood and will appear from the following complete disclosure of my invention that by following the processes of welding herein stated I am enabled to apply molten iron or steel within a shell of copper or an alloy of copper. Therefore I can provide my improved printing cylinder in any kind or type desired.

In Figure l, a base roll 9 of iron or steel is covered externally by a layer 11 of copper or other suitable metal. This layer 11 is applied in the manner hereinafter stated so that it and the base roll 9 are integral. Reference character 12 indicates the weld which unites the dissimilar metals. To effect a proper Weld between copper and like metals to steel or the like, the copper or the like should be heated to a considerable temperature above its melting point, and should be brought to the welding or fusion temperature of the steel. This weld provides a union which is equivalent to the union between pieces of iron or steel after they have been fused together by welding. The layer 11 retains its original properties, the change in the metal, if any, bein'g confined to the thin film 12. e

. In applying the layer 11, I prefer to cover the roll 9 are also protected from rust and from attack by certain inks or dyes used in printing.

In order that the roll just described may be used in a printing press, it is shaped interiorly by forging or machining or a combination of these methods to fit a mandrel or arbor 15, the latter being of a type suited to the press to be used and forming no part of the present invention. The arbor 15 may be provided with akeyway 16 adjacent one end which receives a key 17 formed from the material of the base roll 9. A method of mounting a printing cylinder is fully disclosed in my prior Patent No. 1,891,405, patented December 20, 1932 and following the mounting method disclosed therein, each interior end of the base roll is tapered as at 18 and correspondingly tapered split cones 19 are provided, said cones being slidably received on the arbor 15. One of the cones bears against a removable washer 20 seated in a groove in the arbor and the other cone seats against a.tightening member comprising a ring 21 and a. nut 22. The ring 21 bears against a second removable washer 20. It will be understood that any known or desired means may be used for mounting the base roll on a shaft or the like for use in a printing press.

In providing the base roll 9 with the autogenously welded layer 11, I may cast the layer about the roll, obtaining an intimate union between the base roll and the layer by fusion at their contacting surfaces, or I may provide a self-supporting shell 11 and unite it to the base roll 9 by fusion or by casting the base roll within the shell in a manner tobe described. If the first of these methods is used to effect fusion of the metals, a temperature considerably above the melting point of copper should be used, I preferably first weld a thin film of metal on the base roll, and thereafter cast an outer layer of the same metal against the film of metal originally provided. This permits the casting of the balance of the outer layer at the proper casting temperature of the copper or other layer of metal giving an-improved outer layer. The outer layer of metal as it is cast will integrally unite with the film of metal so that the base roll, the welded film and the cast outer layer are one integra piece. As mentioned previously, I may cast the base roll 9 within a self-supporting shell 11 using means known in the molding art for shaping the interior of the roll 9 as it is cast.

In carrying out the first of the above stated methods for applying the layer 11, the base roll 9 of iron or steel, which in its simplest and preferred form may be an iron or steel pipe, is prepared on its exterior surface by being cleaned thoroughly by any known method such as abrasive blasting if it is covered with scale and oxides. If desired the roll may be cleaned by immersing it in an acid, preferably hydrochloric or hydrofluoric acid as these acids will form a protective coating of chloride or fluoride, or a combination of abrasive and acid cleaning may be used. The chemically applied coating formed by acid pickling volatilizes readily when the molten coating metal is brought in contact with the base roll, exposing a clean metallic surface to the action of the molten metal, facilitating the welding.

After cleaning the base roll is preferably heat-1 ed to the fusing point of the metal. The copper, copper alloy or other layer metal, if it is to be applied to the roll in a molten condition, should also be heated to the fusing temperature of the base roll, and maintained at that temperature during the weld coating operation. The preliminary heating of the base roll is done to avoid abstraction of heat from the highly heated coating metal and to bring it to the fusing temperature. The heated base roll is centered in a mold into which is poured the highly heated coating metal. In this welding step, the mold is heated to substantially the same temperature, as the molten welding metal and pouring of the welding metal into the mold is done under vacuum, insuring no oxidation and no blowholes or imper- Iections of any kind in the outer layer caused from possible gases.

After the base roll is heated and before the covering metal is poured, it may be kept in a neutral atmosphere in the mold to avoid possible oxidation previous to pouring, the arrangement used to apply suction to the mold during pouring being used to supply a neutral gas, the supply of which can be cut off when vacuum is substituted. If desired the pouring may be effected in a neutral atmosphere without the use of vacuum. Any suitable method of preventing undesirable oxidation of the heated roll and metal may be utilized during the pouring of the metal. Preferably the mold and roll are heated together.

As above stated, I preferably first weld a thin film of the coating metal, or of a metal with which the base metal and the coating metal will readily combine, to the roll and thereafter cast against this film a heavier jacket of the layer metal. In applying the welded film, the base roll is first heated, preferably out of contact with the atmosphere and if desired in the presence of a neutral gas, and is immersed in a bath of the highly heated coating metal where it is allowed to remain for a short time. Upon removal it will be covered with a thin layer or film of the coating metal intimately united thereto. The film w'elded roll is next centered in a mold, the rolland mold preferably being heated ap proximately to the melting point of the layer metal to be cast thereon, and a layer of suitable metal heated to its melting point, such as copper, zinc or the like, or an alloy such as brass, bronze, or the like which will combine therewith is cast against the welded film, the cast layer uniting integrally therewith. Between the clipping and casting operations, the film coated roll is preferably kept in a neutral atmosphere or otherwise prevented from oxidizing. This may be done by filling the mold with a neutral gas and placing the roll in the mold immediately after immersion in the bath of highly heated molten metal.

By first providing a welded coating of copper in the manner just described,'brass, bronze, zinc or the like can be cast against the copper film, the molten brass, bronze or zinc combining readily with the copper film at ordinary casting temperatures of the brass, bronze or zinc. latter copper alloys may be readily united directly with the base roll by the described cast welding process if the surface of the base roll is first fumed with the vapors of tin, zinc or a like metal having a low fusing point and capable of readily uniting with steel or iron. The low melting metal used in fuming the surface of the iron or steel of the'base roll does not form a coating thereon of appreciable thickness but the vapors combine with the metal at the surface of the base roll thereby producing a superficial alloying of a particular type and also heating the surface of the roll to a comparatively high temperature. The metallic vapors prevent oxidation of the base roll.

These After the base roll is prepared by subjecting it to the metallic vapors, it'is centeredin a mold and the brass, bronze or other metal poured around it as above set forth. The cast brass or bronze shell and the base roll are integral.

Instead of building up the film welded metal roll after clipping by casting the added metal thereon, the additional metal desired may be electrolytically deposited on the film welded layer, providing a high grade uniform etching layer of electrolyte copper or othermetal integrally united to the base roll, a desirable combination that it has not been heretofore possible to produce.

A printing roll having an integral outer covering of brass or bronze is specially suitable for use in typographical printing processes. The integral copper covered printing roll produced in the manner described above or as described hereinafter is also suitable for typographical printing and its value is further enhanced for this purpose by being chrome-plated after etching.

I may produce the integral multi-metallic printing cylinder of the present invention by casting the iron or steel core within an outer cylinder of solid copper of a thickness corresponding to ,the required thicknes of copper jacket in the finished roll. In casting the base roll in this manner, it may be molded internally by providing a core in the mold in accordance with molding practices known to those skilled in the molding art, so that but very little machine finishing will be needed to prepare the interior of the base roll for mounting on a shaft or arbor, such for example as the arbor of Figure 1.

In producing a.printing cylinder having a molded base roll, the outer shell or jacket of copper or an alloy of copper is placed in a mold having a cylindrical interior with which the shell or jacket .contacts. The inner periphery of the shell against which the base roll is to be cast is coated with a protective paint containing-a powdered purifying metal such as aluminum. The

-m'olten iron or steel which is ,to form the cast base roll is next poured into the mold and as it rises in the mold it melts off the protective coating of paintand contacts with the clean metallic are joined by a weld.

It will be seen from the foregoing that by the present'invention, printing cylinders of any size may be provided, and in use, it is impossible for the layer metal to become separated from the base roll at any stage of the printing process in which my-improved printing cylinders may be used, either due to differences in expansion rates of the metals as the temperatures vary, or during subsequent operations of preparing the cylinder for the reception of new designs or markings to be printed whether such designs or markings are formed by photo-etching, pantographing or hand engraving or other processes which are employed in preparing printing cylinders for intaglio printmg. J

In providing the improved welded printing cylinders for use in the printing arts, it is contemplated to produce the cylinders with a layer having sufficient thickness to provide material for several etched or engraved designs. After a design has served its purpose, the surface of the away, the cylinder can be readily and cheaply renewed by casting new metal against the metal of the layer which remains on the cylinder in the manner above set forth for applyingmetal to the film coated rolls. This method of renewing used or worn rolls bywelding a layer of. metal thereto may also be applied to the salvaging of used copper rolls of the hereinbefore first mentioned prior type. It will also be understood that to avoid reduction in diameter and circumference of my improved printing cylinder, it may be plated with new material'deposited electrolytically after the first design has been removed. When used in this way the improved printing cylinder will always have substantially the same circumference and as its useful life is of indefinite duration it can be used for printing an indefinite number of designs without change in shape.

Figures 3 and 4 of the drawing illustrate another embodiment of theimproved, roll of the present invention. Referring to these figures in detail, it will be seen that the principal difference between the rolls in Figures '1 and 3 resides in the uniform thickness of the wall of the base roll '9. The base roll or cylinder 9 is formed with a wall of substantially uniform thickness throughout its length, the conical surfaces 18 adjacent the ends of the roll being provided by decreasing the diameter of the roll for a short distance adjacent each end as indicated by reference numeral 23. The key 1'7, which is received within a keyway in a shaft or arbor similar to the shaft or arbor 15 of Figure 1', is formed from the material of the base roll 9 at its section of reduced diameter. This base roll may be economically formed from standard steel pipe by forging without the necessity of upsetting of the metal required in the roll construction of Figure 1.

It is impossible, in printing cylinders known to the prior art, for the base roll to have the structure described above in connection with Figures 3 and 4 of the drawing. In fact, the peripheral surface of printing cylinder base rolls heretofore produced must be cylindrical as the print ing surface is applied by electroplating and derives its external shape from the shape of the base roll. By cast welding the external jacket to the base roll, the outer surface of the base roll can have substantially any configuration resulting from the methods, and means employed in the manufacture of the base roll.

,The layer 11 of metal is permanently welded to the base roll 9 by any of the methods set out above and covers the ends of the base roll at 14-.

It will be noted that the thickness of the layer varies because of axiaf variations in the di-' ameter of the base roll and is greatest at the reduced sections 23 of the base roll.

From the foregoing complete disclosure of my invention, it will be apparent that the improved printing cylinder provided thereby is capable of being economically produced, has a useful life greater than that of any type-of printing cylinder known to the prior art and may be used to replace or recondition the prior art cylinders.

The invention may be" embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the

scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be'embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1.- A printing cylinder comprising a base roll of a ferrousmetal and a'layer of a metal having properties suitable to provide a printing surface, saidmetal layer beingautogenously and substantially coextensively unitedto the metal of the base roll. I

2. A textile printing cylinder comprising a ferrous metal base roll and a layer of copper welded substantially coextensively to said base roll,

said copper layer being uniform in texture and adapted to provide a printing surface at any depth.

3. A printing cylinder comprising a base roll formed of ferrous metal and a layer of an alloy of copper welded substantially coextensively to said base roll.

4. A bimetallic printing cylinder comprising a base roll of a ferrous metal to which is united by welding a layer of cast cuprous, metal.

5. In a printing cylinder, a metallic base roll of generally tubular shape and formed with a wall of substantially uniform thickness, the internal bore of said base roll varying in internal diameter to provide mounting means whereby autogenously united to said* base roll, said last named layer being provided with a printing surface formed on said layer of copper.

-'7. A printing member comprising a metallic backing member and a layer of cast cuprous metal welded to said member. a

8. A printing cylinder comprising a metallic base roll and a layer of copper adapted to be engraved, cast against and welded to said base roll which will be suitable to provide a printing surface for said printing cylinder.

9. A printing cylinder comprising a base formed of cuprous metal and a layer of cuprous metal cast on and welded to saidbase, said castlayer of metal being suitable for providing the printing surface on said printing cylinder.

25 EMIL ERICKSSON.

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