US2530388A - Moistening roller for duplicating machines - Google Patents

Description

Nov. 21, 1950 H. R. GULLIXSON MOISTENING ROLLER FOR DUPLICATING MACHINES Filed Nov. 5, 1947 R m w m 719112101 12. Gullr'xaon,

Patented Nov. 21, 1950 MOISTENINGROLLER FOR ,DUPLICATING MACHINES Harold R. Gullixson, Arlington, Va., assignor, by

mesne assignments, to Ditto, Incorporated, Chicago, 111., a corporation of West Virginia Application November 5, 1947, Serial No. 784,242 Claims. (01.101-147) The present invention relates to improvements in moistening rolls for printing and duplicating machines of the lithographic type.

A primary object of the present invention is to provide a moistening roll which has improved characteristics as to smoothness of surface configuration, uniformity of resiliency and moisture absorption.

A further object of the invention is to provide a moistening roll which will not readily become soiled by ink from the impression plate.

Another object is to provide a moistening roll, in which the surface may be readily renewed, from time to time, when the same becomes soiled.

In standard offset lithographic duplicating machines, the moistening roller passes over the inked image on the printing plate, and the surface of the roller tends to collect ink, with the result that frequent changes of the cover of the roller are necessary. The conventional covering now widely used is a special molleton cloth, cut to the size of the roller, tied on each end thereof and sewn along the length of the roller. The varying pull on the thread while sewing creates low spots on the covered surface, with the result that ink readily accumulates on the uneven surface. A special type of woven sock cover has also been developed, with a slight compromise in the wetting characteristics of the cover, in order to provide a smooth surface for the roll.

Both of the conventional methods of applying covers to moistening rolls are difficult, costly, and time consuming. Moreover, covers of these types have a tendency to pack down and become hardened with continuous usage, necessitating operation with excess roll pressure, in order .to obtain even and proper wetting of the printing plate. An attempt to compensate for this defect has been made by using a resilient rubber core, upon which the cover is mounted, but these attempts have not proved entirely satisfactory.

In accordance with the present invention, a thin, non-woven fabric, for instance, of the type made from long staple cotton, such as Egyptian and Sea Island cotton fibers is used as the roll surface. Other types of non-woven fabrics may also be used.

The non-woven type fabric, in strip form of a width corresponding to the length .of the roller is simply wound upon a core in a plurality of convolutions and wetted. Since the surface of this type of material felts readily when wet, a perfectly smooth surface is obtained, and the material provides excellent moistening characteristics. The outer end edge may consist of a plurality of irregularly arranged, outwardly projecting fibers and is somewhat ragged in character, as distinguished from a sharply cut piece of paper or woven textile fabric, although a straight, out edge may be used as the outer end.

The fibers along this edge engage the fibers on the surface of the convolution therebelow, in intermingied, entangled or felted relation, and thus secure the end of the strip in place, thus completely eliminating the necessity for sewing.

The strip should be wound upon the core in a spiral, in a direction, from th inside out, opposite to the direction of normal rotation of the roll in the machine, so that the outer end edge is the trailing edge in the rotation of the roll in the machine. Stated differently, if the winding is done by rotating the core, with the leading edge of the strip secured thereto, the rotation of the core should be in the same direction as that of the roll in the machine.

With a roll so constructed, it is a simple matter to remove the outer surface or cover when the latter becomes soiled. It issimply necessary to locate the outer edge of the strip, felted to the next convolution therebelow, and then peel off one complete convolution. The strip may then be torn or cut from edge to edge and the new end edge so provided secured to the surface by lightly patting the same in place. This procedure provides a new, clean surface for the roll. It will be understood that all conventional duplicating machines provide sufiicient latitude in the adjustments of the moistening rolls to permit this removal of the surface to be performed a number of times, with consequent great saving of time and material.

The roll made in accordance with the present invention has the further adVantage that the outer convolutions felt readily and the outside surface provides an extremely smooth, even surface, while the inner wrappings of the non-woven material provide an excellent cushion of substantial resiliency, Hence, the core may be of rigid, non-resilient material or a soft, resilient material such as rubber.

As stated above, various types of non-woven fabrics may be used in building up the moistening roll in accordance with the present invention. The long fiber type. in which the fibers are adhered together without the use of added adhesive or binder, is preferred, but fabrics made Of short fibers, with or without small amounts of adhesive or binder incorporated therein have proved satisfactory.

The term "non-woven fabric is well understood in the textile art at the present time, and is used to distinguish these fabrics from knitted, netted, and woven fabrics, and also from conventional felt. Examples of non-woven fabrics and methods of making the same are described in United States Patents Nos. 2,023,273; 2,044,937; 2,055,411; 2,168,775; and 2,277,049. These fabrics consist of textile fibers, intermingled and entangled in heterogeneous relation, with the fibers crossed and arranged in an unorganized manner, as distinguished from fabrics made of textile threads, by a weaving or knitting process, in which the fibers and threads are regularly arranged and organized. In some cases, particularly when long staple fibers are employed, the fibers are adhered together without the addition of extraneous adhesive, whereas in other cases, small amounts of adhesive are added. In still other cases, fibers of different characteristics from the majority of the fibers are added to the mats or webs, and then treated to secure the fibers together. For instance, fibers of thermoplastic material, such as cellulose acetate, may be incorporated with cotton or other fibers and the sheets subjected to heat and pressure to secure the fibers to each other. Since fabrics of these types are now standard articles of commerce. it is thought that a further description of them is unnecessary.

In the drawings:

Figure 1 is a diagrammatic side elevation of certain essential elements in a duplicating machine;

Figure 2 is a perspective View of a moistening roll in accordance with the invention; and

Figure 3 is a perspective view of a piece of the non-woven fabric.

The duplicating machine chosen for purposes of illustration is similar to that shown in the copending application of Gullixson and Bruns, Serial No. 712,538, filed January 9, 1946, and may include a main cylinder it. having a plate segment H and an impression segment 12, the former being adapted to support, in clamped relation, a lithographic plate, and the latter being adapted successively to carry sheets of paper through the machine to receive impressions thereon. A transfer roll l5 receives the ink impressions from the lithographic plate on segment H and transfers the same to the sheets on the impression segment i2, as is well understood in the art. Ink is supplied to the plate from an inking roll it and moisture is applied to the plate from the moistening roll ll.

Referring to Figure 2, the moistening roll of the present invention may include a cylindrical core 2!! of rubber or of wood, steel, or other material having spindles 2|, 22 at opposite ends thereof, for support in adjustable hearings in the machine. Wound upon the core 28 in a plurality of convolutions is a strip of non-Woven fabric of the class described above, with the outer edge 25 thereof in the fibrous, rough, or ragged condition, with the individual fibers thereof intermingled, entangled or felted with the surface fibers of the convolution therebelow. Thus, the thin, trailing edge provides no rib or ridge of appreciable thickness on the outer surface of the roll. The fibers 2?, a few of which are represented diagrammatically in an exaggerated manner in the accompanying drawings, are arranged heterogeneously and ma be secured to each other in any of the Ways mentioned above.

When moistened with water, by any of the means conventionally employed in the duplicating machine art, the outer convolutions and the outer surface of the roll have a felt-like appearance, but the inner convolutions retain their original character and resiliency.

The surface of the roll may be renewed, when soiled, simply by lifting the edge 26 from contact with the convolution therebelow, unwinding one convolution, or slightly more than one, tearing or cutting off the soiled material, and resecurin the newly provided trailing edge, by lightly pressing the same in place.

The roll should be inserted in the machine in such manner that the edge 26 is the trailing edge. That is to say, the roll should rotate in use in the direction of the arrow 28, and the spiral winding should be in the opposite direction, as indicated b the arrow 29. Otherwise, the rolling contact of the roll with the plate might tend to unwind the strip.

The invention is not limited to the exact details of construction shown in the accompanying drawings and described above, but includes all constructions coming within the scope of the appended claims and their equivalents.

I claim:

1. A moistening roll for duplicating machines comprising a strip of thin, non-woven fabric sheet material, comprising textile fibers intermingled and entangled in unorganized, crossed relation and pressed together into adherence with each other, said sheet being wound upon itself in a plurality of convolutions and having a rough, ragged outer end edge composed of a great plurality of irregularly arranged outwardly projecting fibers, secured in place by interminglement, entanglement, or felting with the surface fibers of the convolution therebelow.

2. A moistening roll for duplicating machines comprising a cylindrical core member, an elongated strip of thin, non-woven fabric sheet material comprising fibers intermingled and entangled in unorganized, crossed relation, pressed together and adhered at points of crossing, said sheet being wound upon itself in a plurality of convolutions and having an irregular, ragged outer end edge composed of a great plurality of irregularly arranged, outwardly projecting fibers lightly secured in place by interengagement or felting with the outer surface fibers of the convolution therebelow.

3. A duplicating machine comprising a main cylinder having plate and impression segments thereon, a transfer cylinder adjacent said main cylinder, an inking roll and a moistening roll adapted for rolling contact with said plate segment, said moistening roll comprising a cylindrical core and a strip of thin, non-Woven fabric comprising textile fibers intermingled and entangled in unorganized, crossed relation, pressed together and adhered at points of crossing, said strip being wound upon the core and upon itself in a plurality of convolutions on a spiral, from inside out in a direction opposite to the direction of normal rotation of the roll in the machine, whereby the outer end edge of the strip is the trailing edge, said outer edge being irregular and ragged and composed of a great plurality of irregularly arranged outwardly projecting fibers lightly secured in place by engagement with the surface fibers of the convolution therebelow.

4. A duplicating machine comprising a main cylinder having plate and impression segments thereon, a transfer cylinder adjacent said main cylinder, an inking roll and a moistening roll adapted for rolling contact with said plate segment, said moistening roll comprising a cylindrical, rigid core member and an elongated strip of thin, non-woven fabric comprising cotton textile fibers intermingled and entangled in unorganized, crossed relation, pressed together and adhered at points of crossing, said strip being Wound upon said core in a plurality of convolutions in a direction such that its outer end edge is the trailing edge with respect to the normal direction of rotation of the roll in the machine, said outer edge being irregular and ragged and composed of a great plurality of irregularly arranged outwardly projecting fibers lightly secured in place solely by interengagement with the surface fibers of the next convolution.

5. The method of renewing the soiled outer surface of a moistening roll in a duplicating machine, said roll comprising a strip of nonwoven fabric material made up of textile fibers intermingled and entangled in unorganized, crossed relation and adhered together, said strip being wound upon itself in a plurality of convolutions, and having a rough, ragged outer end edge composed of a great plurality of irregularly arranged outwardly projecting fibers secured in 2 place by interengagement with the surface fibers of the convolutions therebelow, which comprises disengaging said edge from the convolution there- 6 below, unwinding at least the outer soiled convolution from the roll, severing the soiled fabric from the strip and securing the new end edge of the strip so formed to the outer surface of the underlying convolution by engaging the fibers along said edge with the surface fibers of said underlying convolution.

HAROLD R. GULLIXSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 90,702 Tucker June 1, 1869 321,075 'Alden June 30, 1885 1,887,507 Hames Nov. 15, 1932 1,927,439 Heifernan Sept. 19, 1933 2,168,775 Hurst et a1. Aug. 8, 1939 2,277,049 Reed Mar. 24, 1942 2,306,044 Davidson Dec. 22, 1942 2,421,824 Allen et a1. June 10, 1947 FOREIGN PATENTS Number Country Date 366,642 Great Britain Feb. 11, 1932

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