US418980A

US418980A - Offset-roller for perfecting printing-machines

Info

Publication number: US418980A
Authority: US
Publication date: 1890-01-07
Anticipated expiration: 1907-01-07

Description

J. T. HAWKINS.

TING PR OFF-SET No. 418,980 Patented Jan. 7, 1890.

UNITED STATES PATENT OFFICE.

JOHN T. I-IAIVKINS, OF TAUN TON, MASSACHUSETTS.

OFFSET-ROLLER FOR PERFECTING PRINTING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 418,980, dated January '7', 1890.

Application filed March 28, 1889.

To aZZ whom it may concern:

Be it known that I, JOHN T. HAWKINS, of Taunton, in the county of Bristol and State of Massachusetts, have invented a new and useful Improvement in Offset'Rollers for Perfecting Printing-Machines, which invention is fully set forth and illustrated in the following specification and accompanyi u g drawings.

The object of this invention is to provide an elastic roller which may be run in contact with the freshly first-printed sides of the sheets or web of paper or in contact with an impression-cylinder in a perfecting printingmachine, which roller shall have an easily-renewable non-absorbent outer covering of such character as will readily take up superfluous ink from the sheets or web of paper or from the surface of the impression-eylinder, and be capable of being cleaned by rolling or rubbing contact of an absorbent roller or wiper therewith.

The invention will first be described in detail. and then particularly set forth in the claim.

In the accompanying drawings, Figure 1 shows a partial outside View, Fi 2 a transverse section, and Fig. 3 a longitudinal section, of the roller.

In said figures the several parts are indicated by reference-numbers, as follows:

The core 1 is made of metal in the usual Way, and the coating 2 is of india-rubber or any suitable elastic substance that will not shrink with age. For the non-absorbent surface the outer film or coating 3 is preferably constituted of a mixtu re of printingink, litho graphic varnish, and a suitable drier, thoroughly dried before being used, or any equivalent composition which will be impervious to, but readily take ink from, a printed sheet, and which can be readily cleaned by a rubbing action. In such a case an india-rubbersurfaced roller would be permeable to or dis solved by oily substances-such as prin ting- Serial No. 305,195. (No model.)

molasses, or glue and clycerine or such other compound as is generally used for the inking form-rollers of printing-machines, which is impermeable to printing-ink, but shrinks considerably with age, this uniformity of surface velocity cannot be preserved if the roller be positively driven by gearing, because of the variations in diameter of the shrinkable compound.

I am aware that an offset-roller composed of glue and molasses or an equivalent composition running in contact with an impression-cylinder of a printing-machine is not new, as such is fully described in Patent No. 227,157, granted Mayat, 1880, and such I do not claim; but

As of my invention I claim An offset-roller for printingmachines, composed of a central core, as 1, an elastic nonshrinltable first coating, as 2, and an outer renewable non-absorbent covering of a compound varnish, consisting, preferably, of printing'ink, lithographic varnish, and a suitable drier, whereby superfluous ink adhering to said varnish-coveril'lg may be readily removed therefrom by an absorbent roller or Wiper, substantially as set forth.

JOHN T. HAWKINS. Witnesses:

J. F. HALEY, ALBERT J. PARK.