US2080127A - Dampening roller for lithographic presses - Google Patents

Description

May 11, 1937.

G. G. GOEDIKE V DAMPENING ROLLER FOR LIT-HOGRAPHIC PRESSES Filed Aug. 22, 1955 @Q gg egggQ Patented May 11, 1937 UNITED STATES PATENT omcs George G. Go'edike, Chicago, Ill., asslgn'or to Roberts & Porter, Inc., Chicago, Ill., 2 corpora tion of Illinois Application August 22, 1935, Serial No. 37,273

6 Claims.

My invention relates to dampening rollers for lithographic presses, and has particular reference to a dampening roller having a seamless, knitted molleton cover thereon, with the nap on the cover extending in a circumferential direction around the roller instead of parallel to the longitudinal axis of the roller. as has been common heretoore.

The primary object of my invention is to pro- 10 vide a dampening roller for use in lithographic presses which presents a smooth external surface without a seam, as distinguished from the usual seamed cover for dampening rollers which in effect causes a ridge to extend longitudinally of the roll with a corresponding uneven surface of the dampening roller of this type, and which is adapted to dampen the plates used in lithograph work properly and evenly, so that the proper amount of moisture is applied to the surface of 0 the plate to prevent the ink from adhering thereto and'to secure proper resilience from the use of these rollers.

Another and further object of my invention is the provision of a dampening roller in which the nap of the covering extends in a direction circumferentially of the roller surface and therefore in alignment with the movement of the roller, thereby assuring that the surface of the roller is smooth and unbroken, of a uniform texture to secure proper dampening of the plates, and providing a structure in which the nap will not become bunched or ridge-like as iscommon with rollers of the present type.

In the present type oi. dampening rollers it is the common practice to provide a covering of molleton cloth napped on both sides, this cloth being woven in the manner common to the weaving of cloths with the usual warpand cross threads, this cloth being produced in lengths of 35 or 40 yards. After being woven the cloth is napped, usually on both sides, and due to the cloth being made in long lengths the napping process of necessity is performed in a direction parallel to the long direction of the cloth, thereby causing the nap of the cloth to extend in the same direction as the warp threads. Thereafter, sections of the cloth are cut, folded and stitched along their abutting edges in sleeve-like form to fit over a composition or rubber roller of the usual form. In order to provide sumcient strength to the cover the sewing operation must extend in a line parallel to the warp thread which, in effect. produces a sleeve in which the warp threads of the cloth extend in a direction 66 parallel to the longitudinal axis of the roller with the result that the nap on the cloth extends in the same direction so that when the sleeve of this type is placed upon the roller, the roller in service is rotating crosswise of the nap of the. goods, thereby causing the'nap to gather together 5 or bunch in service, producing irregular ridges on the surface of the dampening roller. These ridges, in addition to the seam, prevent the roller from functioning properly and dampening the surface of the plate in an even and satisfactory l0 manner.

In my improved construction I prefer to form a sleeve of molleton cloth of knitted threads. thereby eliminating the usual longitudinal seam.

these sleeves being knitted to proper diameter 15.

of various sizes to fit over miscellaneous sizes of rollers, and thereafter napping the surface of the cloth with the nap on the cover extending in a direction circumferentially around the roller so that when the roll is put in service its reciprocat- 2o ing motion over the surface of the plate is in alignment with the direction of the nap on the molleton cover, thereby lessening the tendency of the nap to bunch up on the surface of the roller to form an irregular surface. The nap- 25 ping may be performed only on the outside of the sleeve which is adapted to contact with the plate or in order to enable the cloth to have an added cushioning effect and an equal distribution of moisture throughout the roller it may be napped 30 upon both sides of the cloth, with one napped surface being in contact with the body of the roll while the other or outer side is adapted to contact with the engraving or lithographing plate.

These and other objects of my invention will be 35 more fully and better understood by reference to the accompanying sheet of drawings, in which- Figure 1 is an elevational view of a lithographing roller embodying my invention;

Figure 2 is a sectional view on line 2-4 of 40 Figure 1; and

Figure 3 is a fragmentary elevational view of a section of the knitted sleeve shown in Figures 1 and 2.

Referring now specifically to the drawing and 45 in which like reference characters refer to like parts throughout, the usual lithographing roll is shown having a metallic shaft l0 extending therethrough and a cylindrical supporting body ll of any suitable material such as composition, 50 rubber, fabric, or the like, as may be desired, with a smooth outer surface and upon which aknitted molleton sleeve I2 is placed. The molleton cover I 2 is knitted and as shown in Figure 2 presents a thread having a loop ll formed in the usual to fashion of knitted fabrics of the type commonly called the-chain loop, the sleeves being originally knitted of appropriate size and length to fit various sizes and types, of rolls. The thread may be made of a plurality of strands to secure the proper thickness of the cover. Thereafter the molleton cover I2 is napped, with the nap l4 extending in a circumferential direction around the surface of the sleeve l2. As hereinabove explained, both sides of the molleton cover 12 may be napped, but in any event the napping operation is performed in the same manner on each side of the cloth by having the nap extend in a radial direction around the cloth so that when the roller is put in service its reciprocal movement is parallel with the direction of the nap on the molleton cover.

In operation, the sleeves are first preferably knitted to suitable lengths and sizes, but may be made of woven fabrics produced in the form of sleeves, and thereafter napped with the nap extending in a circumferential direction around the 4 roller, and are then slipped over the rolls either directly or by being turned inside out and forced over the roll in such manner that the molleton cover is stretched taut over the surface of the roll, the roll being slightly resilient so that the molleton cover is drawn taut around the surface of the roll and remains in this position during the life of the sleeve. If desired, of course, the covering can be removed after being worn, and the roller recovered with. sleeves produced as herein described.

While I have described more or less precisely the details of construction. I do not wish to be understood as limiting myself thereto, as I contemplate changes in form and the proportion of parts and the substitution of equivalents as circumstances may suggest or render expedient without departing from the spirit or scope of my invention.

I claim:

1. In combination with a printing roller, a knitted seamless cover therefor having a napped surface, the nap extending in a direction parallel to the rotational movement of the roller.

- 2. In combination, a roller and a knitted fabric cover therefor having a napped surface the nap extending in a circumferential direction around the roller.

3. In combination, a dampening roller including a metallic shaft, a resilient body portion mounted thereon, and a seamless fabric cover for; said body portion having a napped surface the; nap extending in a circumferential direction? around the surface of said body portion.

4. In combination, a dampening roller including a metallic shaft, a resilient body portion mounted thereon, and a fabric cover for said body portion having a napped surface the nap extending in a circumferential direction around the surface of said body portion.

5. In combination, a roller and a fabric cover therefor having a napped surface the nap extending in a circumferential direction around the roller.

6. In combination, a roller and a molleton cover therefor having a napped outer surface, the said nap on the cover extending in a circumferential direction on said roller.

GEORGE G. GOEDIKE.

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