US2649649A - Dampening roll for lithographic presses - Google Patents

Description

Aug, 9 1953 H. H. COLEHOWER, JR 2,549,649

DAMPENING ROLL FOR LITHOGRAPHIC PRESSES I Filed Dec. 29, 1948 mm a INVENTOR.

Harry H Colehowerjz A T T oRNEYs Patented Aug. 25, 1953 DAMPENING ROLL FOR LITHOGBAPHIC PRESSES Harry H. Colehower, Jr., Abington, Pa., assignor to C. Walker Jones 00., Philadelphia, Pa., a corporation of Pennsylvania Application December 29, 1948, Serial No. 67,890

2 Claims. (01. 29-120) This invention relates to dampening rolls for dampening printing surfaces of lithographic presses.

It is known to provide dampening rolls for lithographic presses with cylindrical covers formed of woven fabric cut to size and seamed to form a tube of the proper diameter as well as plain knitted seamless covers and covers formed of terry cloth formed on circular knitting machines in the form of sleeves knitted to the proper diameters and lengths which were slipped over the rolls, for example as disclosed in the patent to C. W. Jones, 2,149,606, issued March 7, 1939.

This invention has for its object the provision of a cover for dampening rolls characterized by the fact that it will present a surface formed by napping loop-s, interknitted with a seamless knitted fabric, in a direction longitudinally of the fabric.

The cover according to this invention will provide a soft, absorbent surface over which the fibres formed by napping longitudinally of the cover will be evenly distributed and will effect an even distribution of water.

Referring to the accompanying drawings in which:

Fig. 1 is a perspective view of a dampening roll having a covering in accordance with my invention;

Fig. 2 is a sectional view of a partially completed cover;

Fig. 3 is a view similar to Fig. 2 of a completed cover; and

Fig. 4 is an exploded perspective view of the cover in Fig. 3 looking along the axis of the cover.

Referring to Fig. 1 of the drawings, the reference character 2 designates a conventional lithographing roll formed of suitable material such as, for example, rubber, composition or any other suitable material having a smooth cylindrical outer surface and provided with the usual shaft 4 and a seamless cover 6 having a contacting surface in accordance with my invention,

The cover 6 is formed on a circular knitting machine of the well known type for forming terry cloth having an inner knitted body portion 8 and an outer body portion formed in series of loops interknitted with the body portion 8 and presenting loops I which extend outwardly from the body 8 as shown in Fig. 2.

The loops ID of the cover shown in Fig. 2 are napped in a direction longitudinally of the cover or parallel with the axis thereof to form a nap on the loops l0 extending longitudinally of the cover as shown at I2 in Fig. 3. In other words,

2 the loops of the cover are napped in a direction parallel to the warp threads.

The completed sleeves or tubes, comprising the cover, after completion are slipped on the roll in the usual manner.

The advantages of my invention result from the provision of seamless covers for dampening rolls for dampening printing surfaces on lithographic presses having a heavy napped surface formed of closely arranged soft fibres extending from the loops ID in a direction longitudinally of or parallel to the axis of the cover. The napped loops ill provide a contacting surface in which the napped fibres completely obscure the loops and body of the sleeve and are evenly distributed over the body portion, whereby a surface formed by the napped loops is provided which will more evenly moisten the surfaces contacted thereby during printing.

What I claim and desire to protect by Letters Patent is:

1. A dampening roll for lithographic presses comprising, in combination, a roller having a seamless terry cloth cover thereon, said cover having a body of closely knitted fabric and a napped outer surface formed of napped loops interknitted with the loops of the body, with the nap extending longitudinally of said cover and completely obscuring said loops, said nap being evenly distributed throughout the circumference of said cover to provide a surface adapted to contain water and evenly moisten the surface contacted during a printing operation.

2. A cover for a lithographic press dampening roll comprising a seamless terry cloth tube having a body closely knitted fabric and a napped outer surface formed of napped loops interknitted with the loops of the body, with the nap extending longitudinally of said cover and completely obscuring said loops, said nap being evenly distributed throughout the circumference of said cover to provide a surface adapted to contain water and evenly moisten the surface contacted during a printing operation.

HARRY H. COLEHO'WER, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 365,728 Carroll June 28, 1887 569,702 Wrightson Oct. 20, 1896 2,080,127 Goedike May 11, 1937 2,117,593 Backofen May 17, 1938 2,144,563 Davis Jan. 17, 1939 2,149,606 Jones Mar. 7, 1939

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