US834026A - Printing-press. - Google Patents

Description

PATENTED OCT. 23, 1906. A. B. SHERWOOD. PRINTING PRESS. APPLICATION IIL'ED 00126. 1905.

"' "H lmlllwll UNITED STATES PATENT oFFioE.

ALEXANDER B. SHERWOOD, OF CHICAGO, ILLINOIS.

PRINTING-PRESS.

Specification of Letters Patent.

Patented Get. 23, 1906.

Application filed October 6, 1905- Serial No; 281,604.

[ sign or matter to-be printed is usually transferred or etched upon a plate or the like Whlch 1s secured to a platecyhnder and in which the inked design 1s imparted to a sheet ,or rubberor equivalent yielding material by 5'Wh1ch the printing is performed.

The rubber printingsheet is-spread overthe printing-surface of a printing-cylirider which cooperates with an impression-cylinder, means being provided fori eoding the sheets to be printed between the ,prii'iting and impression cylinders. It has been usual hitherto in op crating printingresses of this type to provide ashect of ru her to act as the printing surface of alength somewhat exceeding the printing-surface of the printing-cylimler, so

that the 'edgesof the rubber sheet could be engaged by the fastening means of the eylinder, and the rubber sheets have been thus provided irrespective of the dimensions of o the desi ns which thev were intended to print. Ass. consequence each sheet of paper was caused while passing through the press to contact throughout its entire surface with the surface of the dan'ipenrul rubber sheet.

3 5 This has-been the cause of much delay and annoyance, for the reason that all air being expelledv from between the prii ed and printing sheets by pressure of the cylinder the rintcd sheet would tend to cling to the rub- )er printing-sheet in a manner to interfere with. its proper printing and delivery. .lt

hasalso been a difficult matter to keep prinle lug-sheets of such large dimensions sufficiently clean tllll'lllf operation to prevent printed sheets from being soiled thereby.

My object is to owri-oine-the above-named and other objections to the use of a rubber printing-sher.-.t as hitherto employed by pro- ":Vi(li11g the sheet of dimensions no greater so /than the design to be printed inavretpiircand fastening it throughout its rear surface,

referably with su tablecement, to a backlug-sheet, which may be of any suil'h-ble ma iterial, though I prefer to employ for the pur- 5 5 pose a textile fabric, such as canvas.

'llie sacking-sheet 1s of a length sullicient to permit its opposite edges beyond the rubber sheet to be engaged by the mechanism provided on the printing-cylinder for adjusting, tensioning, and securing it in place.

in carrying out my invention I also pro vide the printing-cylinder with. improved backing-s1 icet tensi oiling and fastening means movable to adjust the printing-sheet with referenee to the plate to insure proper registermg.

In the accompanying drawings, Figure l is a section throughthe three cylinders and delivery mechanism of the press, showing my improvementuponthe printing cylinder; and Fig. 2, an enlarged broken elevation. of the printing-cyliiidcr.

A is the plate-cylinder, adapted to receive and hold a )ont plate a, which may be a sheet of zinc, aluminium, or other suitable mate rial, with the design to be printed, trans ferred, engraved, or etched thereon in any suitable manner.

B is the printing-cylinder, provided in one side with a recess 1), in which are shafts c, journaled at opposite ends in bearings on the cylinder. Beyond their bearings the shafts curry ratchet-wheels c, engaged by pawls d on the cylinder.

U is the iinpression-cyliiider, provided with sheet-grips f, and beyond the impression-cylinder is an inclined delivery board or chute g. Between the iinpressiomcylinder and chute is a series of v'cri ii'al airblast nozzles It to facilitate delivery of printed sheets from theimpressh ncyli1ider onto the chute.

ID is a backirig-shoot, preferably of'canvas or other fox tile fabric, of a length to extend over the entire )rinting-surfaec of the printing-cylinder and to be wound one or more times at opposite ends about the shafts c. The shafts may carry studs or points 'i to en gage the ends of the backing-sheet. lroperly located upon the barking-sheet is a surface printing-shoet l), of resilient material. such as rubber, suitable for receiving and printing the design imparted thereto in ink by the plate 1. The printin shcet may be fastened throughout itsrcversc side to the backing-shoot with anysuilable, preferably waterproof, cement, The printing a sheet should in every instance be smaller in dimensions than the sheets of paper to be printed, and for various reasons it is desirable that the print ing-shwt beno larger within reasonable limits than necessary to suitably receive and import at its obverse surface the design i to be printed.

In. placing the backing-sheet on the printing-cy inder-it may. be readily drawn and tensioned by turning one or both of the shafts c, to which it is secured.- By providing two rotary shafts for the backingsheet the printing-sheet may be readily moved in either direction circuinferentially of the cylinder to roperly register it with" the design on the p ate a.

In operation during the rotation of thecyl-= inders the plate a imparts lts Inked design to.

the printing-sheet I), which in turn prints the design upon sheets of paper drawn in the usual way by the engaging and releasing grips f between the'printing and impression cylinders, the sheets being directed by the air-blast onto the chute g, and thus deliveredfrom the press. v

Among the advantages incident to the use of my improvement are that smaller and consequently less expensive sheets of rubber or the like may be employed, that the edges of the printed sheets of paper being free the suction or adhesive action ol the rubber will never be sullicient to withdraw the edges of the paper sheets from the grips f or carry them around the printing-cylinrler, that as to bag amt-stretchinplaces, resulting in bears tgainst the entire surf'ace-of-thewrinkles upon the sheets. This objection is entirely obviated by my invention.

I claim- 1. In a printing-press, the combination with a form-cylinder, of a printing-cylinder, a printing-sheet for said printing-cylin'ler formed 01 yielding material of approxin'iatcly the size of the design to be prlnted, and to which the design on the form-cylinder is transferred, means for applying said sheet to the printing-cylinder consisting of a backing sheet of greater dimensions than the printing sheet and upon which the printing-sheet is secured, said backing-sheet adapted to be fastened beyond the edges of the printing sheet to the printing-cylinder, the size of the printing-sheet being such as to prevent the paper to which the design is finally transterred from being soiled.

2. In a printing-press, the combixnition with a form-cylinder, of a printingrylinder, a printing-sheet for said printing-cylinder to which the design on the form-cylinder is transferred, said sheet being formed of yielding material smaller than the sheet onto which the=design is finally printed, means for ap ilying said. printing-sheet to the printingcylinder consisting of a backir'lg-slleet of greater dimensions than the printing-sheet and upon which said printing-sheet is' secured, said l'Jacking-sheet being adapted to be fastened beyond the'edges'of' the printingsheet to the printing-cylinder, whereby the edges of the sheet-on which the =de'sign printed will be free-fromcontact with the printing-sheet.

ALEXANDER B. SHERWOOD.

In presenee'-of J. H. LANDEs, A.- U. Thomas.

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