US2185766A - Printing press cylinder - Google Patents

Description

. Jan. 2, 1940. K. w. HIGBY 2,185,766

PRINTJ ING PRES S CYLINDER Filed Jan. 3, 1938 INYENTOR. KENNETH w. HiGBY ATTORNEY.

Patented Jan. 2, 1940 PATENT OFFICE PRINTING PRESS CYLINDER Kenneth VF. Higby, Engelwood, N. J., assignor to The Carbornndum Company, Niagara. Falls, N. Y., a corporation of Delaware.

Application January 3, 1938, Serial No. 183,108

11 Claims.

This invention relates to printing presses and particularly to rolls or rollers for use in printing presses and the like. larly applicable to presses in which there are a plurality of cylinders. Some such presses have more than 'a. score of cylinders comprisingv for example feed rolls, squeeze rolls, and compensating rolls.

One of the objects of the invention is to pro- 10 vide cylinders with porous rims that remove excess ink from previously printed portions of the paper sheet and thus. diminish the tendency to smearing or offsetting when the freshly printed paper contacts subsequently with the porous cylinders in the press.

Another object of the invention is to provide such cylinders (especially in multicolor presses) with rims that possess a high coefiicient of friction so that the paper sheet will not slip and so 20 that the successive colors will be printed in correct relative positions.

The principal methods of printing used at th present time may be briefly referred to as:

( 1) Letter press or relief printing.

25 (2) Lithography.

(3) Rotogravure. 4 I

These methods are described in detail in various text-books. These methodsof reproduction of printed matter'and illustrations involve the use 80 of inking machinery to transfer ink to type. etched surfaces, etc., and also means to transfer ink to a sheet of paper, Celluloid or other material that may be used to receive the impressions.

Presses are classified as non-perfecting presses 85 where the press, for example, prints the sheet on only one of the two sides to be printed. An example of a perfecting press on the other hand is one that prints both sides of the sheet with one or more colors and delivers the printed paper 40 folded in form ready to be bound. Presses are also classified as fiat bed presses or as rotary presses, according as the type is distributed on'a fiat surface or on a cylindrical surface.

Difiiculties from offsetting occur particularly 45 in perfecting presses and in multicolored presses,.

but occur in other forms of presses also. Printing presses contain,- especially in the larger presses, cylinders of various sizes including, for example, rollers of various diameters'oyer which 50 the paper is fed Previously to having the first ink imposed on it. Other rollers are used in transferring the paper between the successive impressions and (after the final impression) to the folding machinery. 55 The rollers used in a large press are classified The invention is particuas idler, feed and compensatorrollers along with other designations depending on their particular uses. The rollers with which the present inventionis particularly concerned have as their principal function the transport of the paper through 5 the press without wrinkling and in such a manner as to .minimize the formation of patches of ink which might be smeared on the paper.

The principal function of idler rollers is to change the direction of travel of the sheet, for example, subsequently to printing on one side of a sheet and before the impression on the opp'osite side of the sheet. The principal object of the feed rollers is to transport the sheet without undue sagging. Compensato'r rollers are used to control the feed of the paper in such a manner that a second color will be printed in the correct position relatively to the first color.

In the case of a perfecting press there are rollers which aid in folding the paper into magazineor book form. In the case of a rotary web press the delivery cylinder contacts with the freshly printed sheet. The-dangerof smearin v the white paper in such cases is obvious.

In the past, press cylinders or rolls or roller have ordinarily been made of iron or steel. The result of continued operation is to wear off projecting metal points and to form patches of ink or oil on the metal surface. The tendency for the paper to slip and smooch on the various cylinders isthereby increased.

In accordance with the present invention thepress cylinders (where smearing is most likely to occur) are provided with rims whose structure is in general similar to that of an abrasive wheel of the more open or porous type. The main constituents of the rim of the press cylinders referred to may be, for example, silicon carbide, fused alumina, garnet, flint or quartz which has been reduced to finely divided formand bonded with small portions of clay or synthetic resin. These porous rims are adaptedto absorb ink. The rough surfaces are not so likely to be extensively smeared as is the case where smooth cylinders are employed. Moreover, the abrasive rims used by the applicant have av much higher coemcient of friction than metal rims even where the latter are made rough by sandpapering for example. The use of abrasive rims therefore makes possible more accurate registration of successive color impressions.

The invention is illustrated by means of the accompanying drawing in which:

- Figure 1 shows diagrammatically an arrangement of cylinders which guide and control the movement of the paper sheet in a multicolor press;

Figure 2 is an axial section of a press cylinder made in accordance with the present invention;

Figure 3 is a transverse section taken on the line III-III of Fig. 2; and

Figure 4 is a view of the peripheral surface of an improved cylinder, illustrating the joints between adjacent sections of the cylinder.

Referring to the drawing in detail, a paper sheet is drawn from the supply roll 2 and passed over feed rolls 3 and 4, which may also be described as idler rolls since their function is to guide the paper sheet and not to control 'its speed of travel. They serve also to keep the paper from sagging. The paper sheet is thus fed in between the rolls 5 and 6 at the proper angle. The roll 5 is a type roll or impression roll. The 'roll 6 serves as a backing for the paper sheet while the impression is being made, and may be called a pressure roll. In passing between the rolls 5 and 6 the sheet receives its first color impression. The roller 1 is a compensator roller which is mounted in such a manner as to keep the paper sheet under proper tension to prevent wrinkling and to present the sheet at the proper angle and stretched to the pair of rolls 8 and 9. The roll 8 is a printing roll and the roll 9 is a pressureroll. The sheet receives a second color impression in passing between the rolls 8 and 9. A third color impression is produced by the roll I I and a fourth color impression by the roll l2. The sheet is then similarly printed on the opposite side with the first color by means of the roll l3, with the second color by means of the roll I, with the third color by means of the roll I5, and with the fourth color by means of the roll IS. The sheet which has been printed with four colors is then passed on to rolls i1 and i8 which guide the sheet for entrance into the folding mechanism.

The rollers i, i 9, 2| and 23 contact with freshly printed surfaces of the travelling paper web and are all of the type described above as compensator rollers. These rollers are particularly the subject of the present invention and their structure will now be described. The feed" cylinders and pressure cylinders may, however, be constructed in a similar manner.

As shown particularly in Figures 2 and 3 the improved cylinder consists principally of a core '3! on which is mounted a rim of bonded abrasive 32. A layer of cement 33 is shown between the core 3| and the rim 32. Grooves" 34 are shown (see Fig. 3) in the core to intensify the grip of the cement layer on the core.

The rim 32 is composed of one'or more porous hollow cylinders made up in a manner similar to that used in making porous abrasive wheels. In the present case, however, the primary function of the rim is not one of abrasion. The purpose is to provide the rim with a high coeflicient of friction and to make the spreading or smearing of ink on the rough surface as diflicult as possible. The porosity of the rim is high so that excess ink which contacts with the points of the hard particles will be forced or drawn inwardly rather than spread laterally on the periphery of the rim.

As mentioned above the hard particles may be composed of such materials as fused alumina, silicon carbide, garnet, flint, etc. The-bond can be an inorganic bond such as clay or an organic bond such as heat hardened synthetic resin. v Porosity can be produced by adding to the plastic mix (of hard particles and bond) gas form- 'rollers and the like.

ing materials such as hydrogen peroxide and suitable retarders to control the rate of gas formation in the mix during the molding and the subsequent maturing of the bond.

The methods which are used for making diffuser tubes for sanitary installations can also be used in making the rims of compensating In making diffuser tubes the porosity is closely controlled by jolting a mold containing the mixture of weighed amounts of grain and bond until the mix is reduced to a predetermined volume. Fused alumina is a. very suitable material for the grain. The bonding material is a mixture of clay and flux, the latter being used to obtain conveniently low bonding temperatures in the final stages of the manufacture of the tubes.

The rim is shown in Figures 2 and 4 as made of sections which are cemented together with a cement. As the hardened cement is likely to be less porous than the sections which it joins, the joints are shown as making an angle with a plane perpendicular to the axis of the cylinder. The tendency of the joints to smear the paper is thus reduced.

The improved cylinder has many applications in the printing field in reducing losses caused by offset and in improving the quality of the product. The description and illustrations are given by way of example and many changes may be introduced into the construction of the cylinders without departing from the invention which is defined within the compass of the following claims.

I claim: I

1. In a printing machine one or more pairs of rolls for printing on a traveling sheet, and guide rolls for controlling the direction of movement of said traveling sheet toward and away from the printing rolls, said guide rolls being provided with a porous rim of substantial thickness of rigidly bonded hard granular material, and said guide rolls being capable of being easily reconditioned after periods of use by treatment with a solvent for removing the ink absorbed during use.

'2. In a multicolored printing machine pairs of rolls for impressing successive colors on a traveling sheet, and guide rolls for controlling the direction of movement of said sheet toward' and away from said pairs of rolls and for controlling the tension in said sheet, said guide rolls being provided with a porous rim of substantial thickness of rigidly bonded hard granular material, and said guide rolls being capable of being easily reconditioned after periods of use by treatment with a solvent for removing the ink absorbed during use.

3. In a printing machine means comprising rolls for printing a paper web on both sides, andone or more cylinders for guiding said paper web toward and away from respective printing rolls, one or more of said cylinders having a porous outer layer of substantial thickness of rigidly bonded hard granular material, and such of said cylinders being capable of being easily reconditioned after periods of use by treatment with a solvent for removing the ink absorbed during use.

4. In a printing machine means comprising rolls for printing a paper web with two or more colors, and one or more cylinders for guiding said paper web through the machine toward and away from said printing rolls and for controlling the tension in said web, one or more of said cylinders having a porous outer layer of substantial thickness of rigidly bonded hard granular material, and such of said cylinders being capable. of being easily reconditioned after periods of use by treatment with a solvent for removing the ink absorbed during use.

5. In a printing press, a cylinder for guiding the movement of freshly printed paper and reducing oifset, said cylinder comprising a rotatable support and a porous rim of substantial thickness of strongly bonded hard material, said cylinder being capable of being easily reconditioned after periods of use by treatment with a solvent for removing the ink' absorbed during use, and said rim having an outer cylindrical surface which is coaxial with said support and which has a high coeficient of friction.

6. In a printing press, a cylinder for guiding the movement of freshly printed paper and reducing offset, said cylinder comprising a rotatable-support having a plurality of axially extending grooves on its outer surface and a porous rim of substantial thickness of strongly bonded hard granular material cemented to said support, said cylinder being capable of being easily reconditioned after periods of use by treatment with a solvent for removing the ink absorbed during use, and said rim having an outer cylindrical surface which is coaxial with said support and which has a high coeflicient of friction.

'7. In a printing press, a cylinder for guiding the movement of freshly printed paper and reducing offset, said cylinder comprising a rotatable metal support and a porous rim of substantial thickness-composed of granular fused alumina bonded with ceramic material, said cylinder being capable of being easily reconditioned after periods of use by treatment with a solvent for removing the ink absorbed during use, and said rim having an outer cylindrical surface which is coaxial with said support and which has a high coeflicient of friction.

' 8. In a printing press, a cylinder for guiding the movement of freshly printed paper and reducing offset, said. cylinder comprising a rotatable metal support and a porous rim of substantial thickness of granular fused alumina bonded with a synthetic resin, said cylinder being capable of being easily reconditioned after periods of use by treatment with a solvent for removing the ink absorbed during use, and said rim having an outer cylindrical surface which is coaxial with said support and which has a high coefficient of friction.

- 9. In a printing press, a cylinder for guiding .coaxial with said support and which has a high coeflicient of friction.

10. A compensating roller for printing presses comprising a porus cylinder .of substantial thickness composed of hard granular material bonded to form a rigid body having a high coefficient of friction and which is absorbent of excess ink from freshly printed surfaces, said ink being substantially removable by treatment of the cylinder with a solvent.

vl1. A compensating roller for printing presses comprising a cylindrical support and a porous rim of substantial thickness cemented to said support and o posed of a plurality of sections of bonded granular material, the joints between said sections lying in planes that are inclined to normal radial planes of the roller, said roller being capable of being easily reconditioned after periods of use. by treatment with a solvent for removing any ink absorbed during use.

. W. HIGBY.

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