US1005772A

US1005772A - Apparatus for toning printing-plates.

Info

Publication number: US1005772A
Application number: US615133A
Authority: US
Inventors: Michael Andrew Droitcour
Original assignee: Individual
Current assignee: Miehle Printing Press and Manufacturing Co
Priority date: 1910-12-15
Filing date: 1911-03-17
Publication date: 1911-10-10
Anticipated expiration: 1928-10-10

Description

M. A. DROITCOUR.

APPARATUS FOR TONING PRINTING PLATES.

APPLICATION FILED MAR.17,1911.

1,005,772, Patented Oct. 10, 1911.

l i i i UNITED OFFICE.

i l-[ICHEL ANDREW DROITCOUR, 0FV OAK PARK, ILLINOIS, ASSIG-NOR T0 MIEHLE i :PRINTING PRESS AND MANUFACTURING COMIANY. F CHICAGO, ILLINOIS. A. COB- -PGRATIQN OF ILLINOIS.

Specication of Letters Patent.

arPABA'r'Us non 'roNrNG rientrino-PLATES.

Patented Oct. 10, 1911.

Original application tiledvheceinbcr 15, 1910, Serial No. 597,521. Divided and this application filed March i 17, 1911. Serial No. 615,188.

ToA all wwm it'may concern;

Be it known that '1, MICHAEL A. `Dnorr- COUR, of Oak Park, in the county of 'Cook and State of Illinois, have invented certain '5 new and useful Improvements in Appuratus for Toning Printing-Plates; and vl hereby declare that the following is a full, clear, and exact description thereof, reference being had to the ,accompanying drawings,

I '10 which form part of this specilication.

This inventionrelates to the production of 'toned armada-ready printing plates and resides in an improved means of producing such plates.

The present application is a division of my application for process of toning printv:ing plates tiled Uecember`15, 1910, Serial The object of `this invention is to enable printing platesto be toned without crushingany of the tine lines or dots .in the printing surface thereof during the toning peration.

In this invention I employ (l) a toning 425 member or reverse overlay to determine the graduation'sor tones of the'printing surface of `the printing plate; (2) a novel pressure grader to relieve pressure on those portions of the face of the printing plate #where such 3o pressure would be liable to injure the same; and to obtain increased pressure on other portions of the printing plate where it is necessary in order to produce the desired tones; and (3) a novel pressure plate which 85 is rovided with numerous recesses or channe s in its face opposed :to theback of the printing plate, whereby instead of the metal of the vprinting.;-p'late being compelled to ow. laterally, when under pressure, in order 4 0 to able the plate to be thinnedat those points here iigh lights are desu-ed, the

metal -is permitted to pass 'into minute recesses or chan els-in such pressure plate in'the shortest 1 Y most direct way, so that the face of the prix g plate can be toned with very much less p ire thereon than has heretofore been require( 1 oning process; and the liability of crushing or injuring delicate lines or dots in the printingr 5o surfaceof the printing plate during the` toning thereot` is practically obviated.

The invention will be explained in detail with reference to the accompanying drawings which illustrate, diagrammatcally, one [waetical means embodying the invention.

ln said drawings-Figure 1A is an edge view of a reverse overlay or toning inem# ber. Fig. 2 represents an edge view of an ordinary.printing plate. Fig. 3 is an edge view oi a -pressure plate; and Fig.` 4 is a tace view thereof; Fig. 5 is a sectional View illustrating,r a printing plate, a toning member, a toning pressure grader, and a pressure plate, in a press preparatory' to the ap- 5 plicution of pressure thereto; and Fig. 6 is a similar view showing the parts nmder pressure. Fig. 7 is an edgeview of the resultant toned printing plate Vremoved from' the' press, with the toning member applied `to its facerand Fig. 8 is an edge'view of the ,finished toned printing plate.

The printing plate to be toned may bean clectttype or stereoty e late 1 of usual it is desired 'to have the plate when'tinally toned and ready for use. Such plate, prior to the toning thereof, has a plane printing surface, as indicated in Fig. 2. From this plate a reverse overlay or toning member Q is made in any suitable manner; usually it is made of thin sheets of paper cut and pasted'together so as tomuke this'toning member thicker at 4the points where it is desired to have the plate thinner-,nud vice versa. ln other words this reverse overlay or toning member is made thick opposite construction, but pre era lymade 'about seven-thousandths of an inch thicker thanV the ports of the printing plate which it isl desired shall produce high lights in the impressions taken therefrom,v and is made thinner opposite those iortions of the printing plate. which it. is esired shall prodhce solids or darker shades in the impressionsi 'lhe toningmember 2 is plaeednpon the 4tat-e1 of the printing/plate] and inregister therewith; and then the printing `plate is placed face downward, with the toning member beneath it, upon the bed 5 of a suitallie press, this bed being preferably hea-ted. The press may be of any suitable construe tion, but should be .such that the bed 5 and platen 6 shall be kept truly parallel at all which channels may be about one-sixteenth of an inch dee an preferably extend parallel both longitudinally and transversely of the pressure plate, and divide the undei` siii'- face thereof -into minute squares or projections 3 each approximately one-thirty-second of an inch square, and having their centers approximately one-sixteenth of an inch apart. Preferably the grooves -in the pressure plate are slightly wider at their mouths than at bottom, thus imparting a slight taper or pyramidal shape to the projections 3 so that any metal which may enter the channels can be withdrawn freely therefrom. v

Preferably I intcipose between the back of the printing plate l'and the pressure plate 3, a toning pressure-grader 4 (Figs. 5 and G). This pressure-grader may be formed like the toning member of any suitable material; biit l preferably make it of layers of paper graduated according to the. pressure necessary to effect the desired toning of the printing plate. This toning pre'ssure-grader supplements the action of the toning member 2, being made thicker where the printing plate requires more pressure to-give the desiredtone; and thinner where the surface of the printing plate is of such a nature that pressure would have a tendency to crushj or mash the saine. vIn other words, the pressure-grader 4 is a means whereby the pressure imparted by the press can be varied in its effec-t upon the printing plate according to the subject matter in Vsaid plate. made will protect the delicate parts of the printing surface of the printing plate, which excessive pressure might injure,I and increase the pressure on the printing plato where such pressure is required.

Operation: The printing plate 1, to be toned, is placed face downward upon the bed 5 of the press, with the toning member 2 beneath it but properly applied against its printing surface; the pressure-grader 4 is then laid upon the printing plate and against the bac 3 is arranged or placed above the pressuregrader with its channeled face next the pressure-grader, see Fig. 5. The said pa.

are then forcibly clamped between the press bed 5 andplaten 6; the bed being preferably heated to a temperature of about 3505l The pressure-grader when properly t thereof; the pressure-plate- F. Sutlicient pressure is applied .tp cause the face of the printing plate to conform to the toning member or reverse overlay applied to .the face thereof, the printing plate being inost forcibly pressed toward the toning member where most pressure is re uiied in order to tone the printing plate, an to reproduce on the face thereof the tones of the toning member or reverse overlay. Injury to the printing surface of the printing plate is prevented because the channels in the pressure plate 3 provide a ready outlet for surplus metal, and allow the inetal at'tlie back of the plate, opposite the projections on the toning member, to protrude into said channels, as indicated in Fig. 6; and because the metal can thus crowd back into those channels or recesses there is no lateral [low of the metal in the printing plate such as has heretofore bee`n necessary when a plane surfaced pressure member was employed; hence the toning operation can be effected with very much less pressure upon the printing plate than has hitherto been required. As a result of this pressing operation the face of the printing plate is caused to Areversely 'conform'to the opposed surface of the toning member 2; in other words there will be slight depressions in the face of the printing plate opposite the places where the toning inenibe'i is thick; and there will be projections l" of metal on the back of the printing plate opposite the points where its face is depressed, as indicated in Figs. 6 and 7. To remove sucliprojections and {in}r inequalities from the back of the toned printing plate; the back of such plate may be shaved. as indicated in Fig. 7, while its face is still in contact with the toning member 2; thereby reducing the back of the printing `plate to a plane surface, and making the printing plate of proper thickness for printing, while leaving the face of the printing plate toned in the desired manner. Fig. 7 indicates a toned printing plate re-. moved from the press and ready for the final shaving operation; and indicates at l how the metal luis been forced upward on the. back of the printing plate into the channels of the pressure plate 3; and such printinT plate can be brought to the desired thickness by shaving italong the line c-c by a cutter C, or other suitable means. Afterward the toning member 2 is remov and the finishcdprinting plate, represented in Fig. 8, remains ;-the surface of this -plate being toned ready for printing.

thus produce a printing plate having different-tones iii its printing-surface, as indicated` in Fig. 8, and during the toning operation the surplus metal, where the pressure is greatest, instead of having to flow out in all directions from beneath the edges of the flat press platen can simply move into the ed 12o vss whether suoli pressurej must be greater or ing plates, consisting of a toning member 4 leSS 0D diilnt PRIS 0f the printing plate.; l adapted to be. applied to the face of a printbut where greater p ressure is necessary to ing plate, a pressure :late having minute t tonepart o vits face I locally hold itthere, channelsin its face a apted to be applied. and the metaldoes not laterally 'flow to against the back oi tlie'printing plate,.and I points where it -could damage the plate. '-1 l means for subjecting these parts to pressure; 75 \Vhile.some printing plates might be eil whereby the face of the printing plate is fectively toned withoutl the employment of caused to reversely. conform to the surface the pressure-grader@ yet for fine work the 'of the tonin member and the metal on the most satisfactory results are obtained-- by l b ack of the p ate ispermitted to How or pass using the `pressureader 4,.' as the suc'c'ess l into the channels in the face of the pressure Bo of the tonino' 'operation isf-in the main', it not plate at those points where displacement; rof b altogether, ueto the toning pressure-grader metal is necessitated in order to tonethe; 4 in combination 4with the' pressure plate' 3 printing sui-face of the printing plate in acwhich allows for 'metal displacement .'witlieorclanee with thetoniiigfnieiuber. n 'f' out lateral/flow thereof. Obviously the use 3: In apparatus fo'r toning printing sii ofthe pressure plate 3 greatly lessonsv the plates, a toning menil'ier adapted tube apamount of pressure heretofore required to plied to the face of a printing plate, a prestone aprinting plate,lessens the danger of y sure-grader adapted to b e applied to the crushing the printing surface of thepriiitl back thereof, and means t'or 'subjecting the ing plate' during the pressing operation; l saidparts` to. pressure sufficient to cause the 90- and removes'the danger of distorting g printingsui'face ofthe printing plate tol: lines iii the-printing surface of the printing reversely conform to the toning xnember. lute by lateral How of metal thereinduring I 4r.A Apparatus for toning printing lates, l toning operation.- consisting: of 'a toning member adapte to be' The pressure-grader'as above stated enapplied to tlieface of a printing plate, a 95 ables greater pressure to be applied to'any pressure-grader adapted to be applied to portion of the rinting, plate where it may l the back thereof, a pressure plateliavinga be desired, Wit out affecting the tone imchanneled surface adapted to be applied parted t0 the rinting surface of the piintagainst the pressure grader, and means for ing late by t e toning-member. It would subjecting said parts to suliicient pressure to. 100 not o to thickenthe tonin r member to gain cause the printing surface 'of the jprintinflfA increase of pressure at suc points becausel plate to reversely conform to the opp the thickening ofthe toning member would surface of the, toning member. alter its toning eect upon "the printing'4 5. Apparatus. 'fortoning printing lates, plate. But by usingiboth a toning -menilier comprising toning member adapte to be 10,5 and i1- pressure-grader I'can obtain the most' applied to the face of a flat surfaced printdelicate toning effects in -the face 'of Ithe ing late, a. pressure-grader adaptedto be printing plate and at the same' time obtain applied to the back of said printing plate, a any desired graduations in the pressure upon pressure plate having a channeled surface the printing plate that will facilitate the adapted vto b e applied against the toninr. Itoning operation, and enablethe'sameto beV layer, and means for subjecting the erformed expeditiously Aand economically arts t lpressure sullicient to cause the printin any ordinary press, And the employment ing surface of the pi'iiiting plate to reverscly of a channeled pressure plate 'inconnection` conform to. the toning member; the metal with the toning member and pressaregradcr at the"baclc of the plate passing into the 115 localizes excessive pressure on the printing .channels in the pressure late at the points plate 'by obyiating lateral flow-ofthe metal where ldisplaccmentof tie metal is necestherein, which otherwise wouldtend-to How l'sary toeil'ect toning o f thc-printing plate laterally and distribute the pressure equally 'in accordance with the toning member. throughout the printing plate.' (3. The herein described apparatus for 129 WhatIclaim is: toning printing plates, comprising a re' 1.In' apparatus for producing toned 'veisc overlay adapted to he applied to the rinting plates, a toning member adapted to'l faceof a llatsurfaced printing plate, a pres1 e applied to the printing Vsurtaceof a print i sure-grader adapted to ,be applied to the ing plate, a (weled pressureplate vadaptback oflsueh printing plate., a pressure plate ed to-beav plld against the back of' the having a' channeled,surface adapted to be printing p ate, and means for-subjecting 4applied to the p|'ess \iicgi'ader; and means ,these parts to pressure whereby the metal for subjecting the said partsl to pressure to on the back of the plate is permitted to flow cause the -printiug surface of the printing 3o adjacent channels in the pressure plate 3; pressure plate and the face of the' printing thus obviously overcomin 0f the metal and locally iolding `tliepifessurface of the toning member.

sure necessary to tone the printing' plate, 2. Apparatus for'producii'ig toned print-.

or passinto the channels in' the facev of the plate -to reversely conform' to the oppose the lateral f .iow plate is caused to reveisely conform to the.

surface of the reverse overlay, and sur lus as my own, I afui my signature 'in presence metal in the back of the plate to flow into of two witnesses. the channels in the pressure plate at those points where displacement of the metal is MICHAEL ANDREW DROITCOUR' 5 necessary to effect the toning of the printing lVitnesses:

plate. CHAS. HICK'MAN,

In testimony that I claim the foregoing PERCY G. SHAW.