US 2966724 A
Description (OCR text may contain errors)
Jan. 3, 1961 M. c. swoPE 2,966,724
DAMPENING ROLLERS Filed Feb. 6. 1959 Fig. lb I2 I.
United States Patent DAMPENING ROLLERS Morris C. Swope, Bryn Mawr, Pa., assignor to Perfex Corporation, Bryn Mawr, Pa., a corporation of Pennsylvania Filed Feb. 6, 1959, Ser. No. 791,703
4 Claims. (c1. 29-120 This invention relates to dampening rollers for offset printing machines and has for an object the provision of disposable dampening rollers of high quality.
As well understood by those skilled in the art, dampening rollers have presented annoying delays in the operation of offset printing machines because of the relatively short life of the covering required to carry the water or other dampening media to the printing plates. Because of the wear of the dampening surfaces numerous proposals for the renewal of such surfaces have been made. It has been further proposed to provide on paper or fiber tubes dampening materials which may be considered in the disposable class, at the option of the printer. So far as known, these suggestions have left much to be desired and particularly in the provision of disposable dampening rollers which can be applied to existing printing machinery of the offset type without the need of modifying the shafts and shaft supports to take care of the disposable dampening roller.
It is an object of the present invention to provide a dampening roller which may be used quickly to replace a roller on a machine, the surface of which has outlived its usefulness.
In carrying out the invention in one form thereof, there is provided a low-cost inner core preferably made up of a large number of turns of paper. Such spirally wound inner cores are strong and to each there is adhesively secured the moisture-carrying material. Each core has associated therewith core elements which not only form a driving engagement with the core but also are adapted to journal the core and to form a driving connection with other equipment for rotation of the dampening roller as needed in printing operations.
For further objects and advantages of the invention, reference is to be had to the following description taken in conjunction with the accompanying drawings, in which:
Fig. 1 is a sectional view of a dampening roller embodying the invention;
Fig. 2 is an end view of the roller of Fig. 1;
Fig. 3 is a side elevation of a plastic core plug for the roller of Fig. l; and
Figs. 4 and 5 are sectional views of modified forms of the invention.
Referring now to Fig. l, the dampening roller comprises a low-cost inner core 11 made of spirally wound paper and having a substantial thickness to impart the required rigidity and strength to the roller as a whole. The paper as it is wound is coated with an adhesive so that the finished core is a laminated solid unyielding mass. To the outer surface of the core 11 there is adhesively bonded, as at 12a, the moisture-carrying material 12. The adhesive is of a moisture-resistant type, such for example as National Adhesives No. l0-R-3 054. The moisture-carrying material of molleton, velveteen, pile fabric and the like is preferably spirally wound upon the core 11. When spirally wound on the 7 Patented Jan; 3, 1961 lC V core and secured thereto by an adhesive of the permanently setting type, there is eliminated entirely the possibility of loosening of the moisture-carrying material during operation, a matter which has given concern in the prior use of pressure-sensitive cements or adhesives.
Within the respective opposite ends of the core 11 are disposed molded or machined inserts 13 and 14. These inserts are preferably made of a plastic or resin material of the high-impact type, a number of which are available on the market, such as nylon, and including the resins such as high-impact styrene, polyethylene, and the resins of the phenolic type.
Each of the plastic inserts 13 and 14 is adhesively secured to the core 11, glue-carrying passages 13a and 14a being provided for the adhesive. Preferably each insert is made slightly oversize so that it is also disposed in a press-fit relation within the opposite ends of the core. As best shown in Fig. 2, the outer flange portion of each insert includes projections such as 14b and 14c engageable with complementary recesses in a driving member for power drive of the dampening roller. Insert 13 has like driving lugs 13b and 13c.
The exposed surfaces of the core 11 are treated with a moisture-resistant material such as cellulose acetate or a cumar-indene resin solution, or the like.
Dampening rollers as disclosed in Figs. 1 and 2 have been found to be highly satisfactory in operation and readily adapted for immediate installation in existing printing machinery. They lend themselves to ready replacement of dampening rolls, the coverings of which have been used beyond their useful life. The cost, in view of the savings in shut-down time, justifies their use as disposable items. Their use avoids entirely the troublesome operations heretofore required to replace the moisture-carrying covering materials whether they be of the stocking type or whether they include pressure-sensitive adhesives by means of which the coverings are to be secured to the cores.
Now that the principles of the invention have been example, the core inserts may be made of steel or other materials. As shown in Fig. 3, the core inserts may themselves form shaft extensions for the roller. Thus, the insert 26 may have a cylindrical end portion 27 which can be adhesively secured to the inner wall of the core 11 with the inner surface of a flange 28 abutting an end of the core 11. As in Fig. 1, glue-carrying passages 26a are provided. The end 29 may have a diameter differing from the end 27 and will form the bearing support for the dampening roller.
In each modification of the invention, it is to be noted that the cylindrical core 11 is of a substantial thickness, at least one-third the diameter of the dampening roller taken from its center to the region of the glue line for its covering of water-carrying material. It is to be further noted that the core is water-resistant. When made of multiple layers of paper, either spirally or convolutely wound, it is treated with a water-resistant material. The core may also be made up in inexpensive core material other than spirally wound paper so long as it has the adequate strength and thickness obtained by the multiple layers of adhesively coated paper mentioned above. Thus, the structure of the present inven tion is to be contrasted with that heretofore utilized in rollers of the type used for roller-painting and the like. While in roller-painting a generally circular configuration will be satisfactory, for a dampening roller it is essential that the roller throughout its length be rigidly circular. By providing substantial thickness, at least onethird the diameter, there are provided both adequate strength and retention within close tolerances of a circular shape throughout incremental lengths of the roller. Thus, there has been achieved at low cost a truly cylindrical roller carrying the dampening material needed for the printing operations.
In Fig. 4 a shaft 15 is provided with an outwardly extending flange 16 having tangs or pointed projections 16a or other projections extending inwardly into the core 11 for driving engagement therewith. On the opposite end of the shaft 15, there is disposed a companion flange 17 also having tangs 17a impaling the core 11 and forming a driving engagement therewith. The flange 17 after being pressed into the illustrated position is secured to shaft 15 by a set screw 18. It will be obvious from the above description that the dampening roller may be readily removed by loosening the set screw 18 and sliding it from the shaft 15, the replacement operation being but a reversal of the foregoing steps.
Where existing machines utilize both a solid shaft 20 and a metal cylindrical core 21, Fig. 5, within the dampening roller (not shown in Fig. the core inserts 22 and 23 may be of steel or a plastic such as one of the abovedescribed resins. They have been illustrated as a metal, such as steel. They include fangs 22a and 23a for engagment with the core 11, not shown in Fig. 5. Each core insert includes an inner cylindrical portion 22b and 23b which, like the inserts of Fig. 1, terminate in outwardly extending flanges having on their outer faces the driving elements or projections, like those shown in Fig. 2, for cooperation with driving members of the printing machinery. The flange 22 is secured to the cylindrical member 21 by screws 25, while flange Z3 is secured to member 21 by tapered pins 30 extending radially thereof.
It is again emphasized that the present invention is characterized by its simplicity and by the avoidance of complicated clamping arrangements, threaded elements of all kinds, and by the presence of prefabricated end arrangements in driving engagement with the core and of the configuration required for the particular offset machine in which the dampening roller is to be utilized,
What is claimed is:
1. For carrying water to the printing plates of an offset printing machine, a dampening roller comprising a rigidly circular cylindrical core having a minimum thickness of at least one third its diameter to provide retention within close tolerances of a circular shape throughout incremental lengths of the roller during operation thereof, and having an opening extending axially thereof, a water-carrying outer covering adhesively secured to said core by a water-resistant cement, said covering being selected from the group consisting of molleton, velveteen and pile fabric, core inserts extending inwardly into said opening from opposite ends of said core, and means forming a driving engagement between said inserts and said core for driving said core, each of said core inserts having flanges engaging opposite ends of said core, said core being water-resistant, and said core inserts having driving lugs projecting axially thereof for positive drive of said core in applying water to the printing plates.
2. The dampening roller of claim 1 in which said inserts have openings coaxial with the core for support of the core on a shaft.
3. The dampening roller of claim 1 in which said core is made up of multiple layers of paper adhesively secured together in spirally-wound relationship and shaped into a core which is uniformly circular lengthwise thereof.
4. The dampening roller of claim 3 in which said multiple layers of paper are provided by winding the paper upon itself to produce at least said minimum thickness of said core.
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