US1663876A - Method of correcting printing plates - Google Patents

Description

' 1 arch 21, 1928. 1,663,876

L. W. CLAYBOURN METHOD OF CORRECTING PRINTING PLATES Filed Jan.4. 1926 2 sheets-sheet 1 2 5 2| "2?. M at LEEJ!!! $9 March 27, 1928. 1,663,876

L. w. CLAYBOURN METHOD OF CORRECTING PRINTING PLATES Filed Jan.4. 1926 2 Sheets-Sheet 2 Patented Mar. 27, 1928- UNITED STATES l 1,663,676 PATENT OFFICE.

LESLIE w. CLAYBOURN, OF MILWAUKEE, WISCONSIN.

METHOD CORRECTING PRINTING PLATES.

Application filed January 4, 1926. semi 116. mm.

Printing plates as ordinarily made contain variations in the printing surface, some portions being lower and therefore printing lighter, and other portions being higher and therefore printing heavier, and therefore making overlaying or underlaying or hoth necessary before proper prlntmg impressions can be made.

with little or no previous overlaying or.

underlaying for minimizing the necessity of make-ready, and to accomplish this by rolling pressure upon the rear face of the prmting plate and, further, to press the printing portions of the printing surface of the printing plate by rolling pressure into the same surface as determined by printing pressures.

It is the object of my invention, further, to exert rolling pressure upon the rear face of the printing plate sufficient to overcome the resistance to local flexure in the printing portions in the printing plate for shaping said printing portions for proper printing; further, to apply roller pressure upon the rear face of a prmting plate in spaced-apart paths with pressure suflicient to overcome the resistance to local flexure in the printing portions of the printing surface of said printing plate; further, to apply roller pressure upon the rear face of a printing plate in spaced-apart and alternating paths with pressure suflicient to overcome said resistance to local flexure; and, further, to apply said spaced-apart and alternating paths in close relation upon the rear face of the printing plate. It is the object of my invention, further, to correct the curved printing surface of a curved printing plate by roller pressure applied in a curved path to the rear face of the curved printing plate and with pressure sufficient to overcome the resistance to local flexure in said printing portions; further, to apply said pressure in curved spaced-apart paths: further, to apply said pressure in curved spaced-apart and alternating paths; and, further, to apply said pressure in spaced-apart and alternating paths closely related in time of application.

It is the object of my invention, further, to cause compression of the printing plate by means of said rolling pressures, and, further, to cause said compression in the printing plate with rolling pressure which is greater per area of printing surface than the printing pressure per area applied to said printing surface.

My invention consists further in novel method for accomplishing the objects hereinbefore stated, and the invention will be further readily understood from the following description and claims.

I have exemplified apparatus employable in performing my method, although other apparatus may be employed for the purpose,

and it will be understood that my improvedmethod is not dependent on apparatus in performing the same.

I do not herein claim the means exemplified in performing my improved method, having shown, described and claimed the same in a copending application, divisional hereof, filed by me in the United States Patent Oflice Jan. 6, 1927, as Serial No. 159,389,

for patent on improvements in apparatus for compressing printing plates.

In the drawings Fig. 1 represents a vertical axial section of an apparatus for correcting a curved printing plate according to my improved method.

Fig. 2 is a cross-section of the same, taken in the plane of the line 2-2 of Fig. 1.

Fig. 3 is a plan view of the same, partly broken away, with the resistance member removed for better illustration of the pressure members.

Fig. 4 is a detail view of one of the pressure members, partly in section on the line 4. .1 of Fig. 3.

Fog. 5 is a detail view of the same, taken in section on the line 5 5 of Fig. 4.

Fig. 6 is a plan view of the rear face of a curved printing plate partly corrected by my improved method, and partly broken away.

Fig. 7 is a vertical cross-section, showing an exemplifying apparatus for correcting curved printing plates, in which the resistance member is, located under the pressure devices.

Fig. 8 is a vertical longitudinal section of an apparatus partly broken away, taken in the plane of the line 1O of Fig. 8, show-- recting flat printing plates in accordance with my improved method.

Fig. 9 is a vertical section of the same partly broken away, taken in the plane 0 the line 99 of Fig. 8.

Fig. 10 is a horizontal section, taken in ing the pressure rollers and the mountings for the same.

Fig. 11 is a plan view, partly broken away, of one of the pressure rollers; and,

Fig. 12 is an enlarged vertical cross-section similar to Fig. 7, showing differences in printing surface.

My method is applicable for compressing printing plates, such as stereotype plates for use in newspaper printing, electrotype plates, and various other kinds of printing plates used in the printing art, and is applicable to such plates whether such plates be curved or flat.

I have in Figs. 1 and 2 exemplified an apparatus which is particularly adapted for correcting curved stereotype plates, employed in newspaper printing, which stereotype plates are usually quite thick and of substantially equal dimensions. In Fig. 7 I have exemplified an apparatus employable in correcting curved printing plates, which may be stereotype plates above mentioned, or curved printing plates such as are used in general or miscellaneous printing, and which are of usual thicknesses for printing plates of this character, which thicknesses are less than the thicknesses of newspaper stereotype plates, the apparatus being also adapted for various sizes of curved printing plates.

In Figs. 8, 9 and 10, I have exemplified an apparatus employable for applying my improved method to fiat printing plates.

My invention is employable upon printing plates which are of substantial atmospheric temperatures, or at the temperatures at which said printing plates are used in printing, or upon printing plates which are in heated state, being subjected to my improved method immediately after heat casting the same and prior to the cooling thereof, or by being subse uently heated in order to increase the pliability of the printing surface of the same, or at other temperatures, and whether such printing surface be on the material out of which the bodies of sterotype plates are cast, or upon the copper or other shell, as is customary in electrotype plates, which latter also have a backing for the shell of usual backing material, wellknown in the art; or the printing plates may be composed of such other materials as may be customary or desired.

In carrying out my improved method, I provide a resistance member to resist pressure upon the printing plate. Such resistance member in Figs. 1 and 2 is exemplified as an arch-piece 21, of suitable ressure resistance material, "such as meta and provided with a resistance surface 22, the resistance portions of which are preferably in the same surface, exemplified as the sector of a cylinder. this surface being preferably the same surface as determined by printing pressures, for the reason that the exactness of correction desired in my improved methfluid. The partitions 32 between the cavities may be, provided with ports 33 for the purose.

The printing plate is shown supported by having its respective edges ride on supporting rollers 35, of which there may be a suitable number at each side of the recess 36 in the frame, the supporting rollers being respectively suitably rotatably supported on suitable journal bolts 37 threaded into the side walls of the channel. The printing plate may be introduced endwise into the space in the arch piece through an opening 38 at one end thereof, and be removed endwise through an opening 39 at the other end thereof.

The printing plate is subjected to rolling pressure applied to the rear face 41 thereof, preferably in spaced-apart paths, which are preferably applied alternatingly, with the beginnings of the paths preferably in close relation. These spaced-apart paths are exemplified in Fig. 6 at 42 and 43, the alternating paths being shown interrupted for better illustration. The paths of one of said sets of paths preferably fill the s aces between the paths of the other of sa'i sets of paths.

These pressures are applied across the rear face of the printing plate progressively throughout the area of the printing portions of the printing plate, with pressure sufficient to press all portions of the printing surface of the printing plate onto or parallel with said resistance surface, the pressures being preferably suflicient to overcome the resistance to local fiexure in said printing surface, in order to press all the portions of the printing surface of the rinting plate into the same surface, as etermined by printing pressures, so that, when said printmg plate is put in lace in the printing press into coaction wit a tympan, such as a tympan cylinder or a fiat tympan, all resistance portions of which are in the same surface, that said printin surfaces will properly receive the ink rom the inking evlces of the printing press throughout the printin area thereof, and make a printing impresslon upon the sheet to be printed, supported by said tympan, without the necessity of or with a. minimum amount of underlaying or overlaying for producing a uniform impression throughout the printing area.

The rolling pressure 11 on the printing plate is also preferably su cient to compress the body of the printing plate into a density at least as great as the density by print ing pressure upon the printing plate.

The rolling pressure upon the printing plate is exeinpli ed as accomplished by pres sure rollers 51, 52, exemplified as in spaceda art relation by the spaces 53, 54, between t e same, the pressure rollers also being preferably arranged in a plurality of sets or rows, the rollers in the respectivesets being in alternating paths. The alternating paths of pressure act ugpn the printing plate at one operation of te apparatus exemplified.

If desired, one of the spaced-apart sets of rollers may be employed for spaced-apart paths-of pressure upon the printing plate, lateral movement between the printing plate and the rollers being then made for coaction between the same pressure rollers and the printing plate in the spaces between the paths of pressure previously applied to the printing plate.

The pressure rollers are exemplified as having protuberances 56 and depressions 57 preferably having sloping walls 58 therebetween. Providing the protuberances, and inversely providing the depressions, aided by the sloping walls when employed, enables pressures to be applied more'readily through the thickness of the printing plate, and enables more ready transference of such localized pressure from the rear surface of the printing plate to the printing portions of the printing surface of the printing plate, whereby to press all parts of said printing surface into the same surface, preferably as determined by printing pressures, and with pressure sufiicient to overcome the resistance to local flexure in the printing portions of the printing plate, in order to reduce all parts of said printin portions to the same surface, also preferab y determined by printing fpressures. 7

ese protuberances and depressions may be of various forms for obtaining the results desired. They may for instance be such as more fully shown and described in my Patent No. 1,549,185, for method of correcting printing plates and printing plates produced thereby, dated August 11, 1925. The rollers are preferably of hard material, such as steel, although other materials may be employed. The unevenness of printing surface usual in printing plates, herein described, is also lly shown and described in my aforesaid patent.

The pressure .rollers are exemplified as mounted on axles 61, on which the may be rotatable, the axles being supported in bearings 62, in which they are axially held in suitable manner, the bearings being in okes 63 of lovers 64, pivoted on pivot-r s 65, supported in bearings 66, 67, of a rotary sup ort 68. This rotar support is on a sha t 69, shown fixed t ereto by pins 70, the shaft being journaled in bearings 71, 72, on the frame. The shaft is suitabl driven, as by having a worm-wheel 73 fixe thereto,

a worm 74, suitably driven, meshing with the Worm-wheel.

Pressure means for the rollers are exemplified as springs 75, located in sockets 76 in the rotary support. The springs respectively surround plungers 77. Each of the plungers is provided with 'a shoulder 78, between which and the bottom of the socket the spring is located. The inner end of the plunger is received ina hole 79, while the outer end of the plunger acts upon the lever in which the roller is located. These plun ers bear against lugs 80 at the swinging en 5 of the levers.

Means are provided for maintaining the levers in their proximate positions, while permitting their free movements for affecting pressure upon the printing plates and for variations in thickness of the printing plates. For preventing excessive swinging of the pressure rollers away from their rotary support, the levers are provided with retaining lugs 81, with which latches 82 on the rotary support coact, these latches being in the form of lugs releasably held to the rotary support in obstructing relation to the lugs 81 by bolts 83, extending through the lugs 82 and threaded into the rotary support.

The release of any latch permits ready swinging back of the lever held thereby out of the way of the spring, for replacement of the spring, in order that springs of sufficient pressure may be provided for the printing plates which it is intended to correct, and for other attention to the levers and the parts associated therewith.

The printing plate which it is desired to correct by employment of the apparatus shown in Figs. 1 and 2, is moved axially under the arch-piece 21, on the supporting rollers 35, against an end gage 84 suitably releasably supported, as by being pivoted by a pivot 85 to the bearing 72. This end gage may be moved into obstructing relation with the plate, in order to position the plate, and be swung toward the hearing when the plate is to be moved endwise past the hearing. The plate may be preliminarily supported on supporting rollers 86 in line with the supporting rollers 35 on an infeeding bracket 87, and be supported on outfceding rollers 88 on an out-feeding bracket 89.

When the printing plate has been moved into coacting relation with the arch-piece 21, it being understood that the pressure rollers are then in lowered position, under the operating shaft 69, the operating shaft is caused to rotate for moving the pressure rollers in paths about the inner or rear face of the curved printing plate, so as to press all portions of the curved printing plate, the paths of pressure moving progressively across the rear face of the printing plate for pressing the printing portions of the printing surface of the printing plate toward the resistance member, and pressing saidprinting portions into' the same plane, and flex ing the printing portions of the printing. surface which are not in the proper surface into said proper surface for uniform printing effect of the printing portions of the printing plate, the fact of location of the printin portions in said same surface being prefera ly determined by printing pressures.

The action of the pressure rollers is also preferably to compress the body of the printing plate. The compression may produce a density of the body of the printing plate as great as the densitydue to printing pressure upon said printing plate, in order to resist collapse of the printing plate during the printing, for instance, during the prlnt-ing of a long run from the same plate.

It is to be .understood that after pressure treatment of the printing plate, the rear face of the printing plate is finished, as by shaving, for removing unevenness caused by indentations of said rear face by the protuberances on the pressure rollers, and to reduce the printing plate to an even thickness at its printing portions, and other operations are performed on the printing plate, as may be desired, or as more fully shown and described in my aforesaid patent.

In the form shown in Figs. 1 and 2 there is preferably sufficient space between the printing surface of the printing plate and the resistance face 22 of the resistance member 21, when the edges of the printing plate ride upon the supporting rollers 35, to prevent abrasion between said printing surface and said resistance face, the pressure rollers pressing said printing surface toward said resistance face when acting upon the printing plate.

I have in Fig. 7 exemplified an apparatus in which the arch-piece is shown as a trough 121, and a gage 135 is provided for limiting rotary movement of the printing plate. The printing plate 125 is, in this instance, preferably introduced into the trough and removed from the trough from the top of the trough. The elements illustrated in this figure, similar to the elements shown in Figs. 1 to 5 are designated by similar reference numerals, raised to the series one hundred. In this exemplification the idle positions of the pressure rollers are above the rotary support.

I have in Figs. 8, 9 and 10 exemplified my invention as applied to fiat printing plates, rollers similarly mounted being exemplified.

In this instance, however, the rotary support is shown as a support 268, mounted on the frame 227, and the resistance member is exemplified as a bed 221, on which the printing plate 225 is supported, with its prlnting face down. Endwise movement of the printing plate is limited by an end-gage 235.

Relative reciprocating motion between the pressure rollers and the printing plate is accomplished in the present instance by reciprocating the bed or support, which may be accomplished in suitable manner, as by providing the bed with a. rack 295, meshed by a pinion 296, on a shaft 269, suitably between the straight or curved resistance face and the printing surface of the printing plate.

The elements in Figs. 8, 9 and 10, similar to elements shown in Figs. 1 to 5, are indicated by similar reference numerals raised to the series 200.

The variations in elevations in the printing surface of the printing plate, after being eleetro-deposited or cast, or both, and the correction imparted by, my improved method, as hereinbefore explained, are exemplified in Fig. 12, in which the curved elcctrotype plate 125 shows lower printing portions 144 and higher printing portions 145, all brought to the same printing level 146 by my improved method.

Having thus fully described my invention,

what I claim as new, and desire to secure by Letters Patent, is:

1. The method of correcting printing paths with pressure pressing all printing portions of said printing surface into said predetermined surface as determined by printing pressures.

2. The method of correcting printing plates which comprises resisting the printing surface of the printing plate by a face, all portions whereof are in a predetermined surface, and applying roller pressure upon the rear of said printing plate in spacedapart and alternating paths with pressure pressing all printing portions of said printing surface into said predetermined surface as determined by printing pressures.

3. The method of correcting printing plates which comprises resisting the printing surface of the printing plate by a face, all portions whereof are in predetermined surface, and applying roller pressure upon the rear of said printing plate in spaced-apart alternating paths progressing across said rear of said printing'plate in close relation and with pressure to press all printing portions of said printing surface into said predetermined surface as determined by printing pressures.

4. The method of correcting printing plates which comprises resisting the printing surface of the printing plate by a relatively unyielding face. all portions whereof are in the same surface and applying rolling compression by rolling surfaces having indentations upon the rear face of said printing plate in spaced-apart alternating paths progressin across said rear face of said printing p te in close relation and with ressure compressing the body of said rintmg plate and pressing all portions 0 said printing surface into the same surface as determined by printing pressures.

5. The method of correcting curved print-.

ing plates which comprises resisting the prmtmg surface of said printing plate by a concavely curved surface and exerting pressure overcoming the resistance to local flexure in the printing portions of said printing surface progressively upon the rear curved surface of said rinting plate for pressing the printing portions of the printing surface thereof into a predetermined curved surface.

6. The method of correcting curved printing plates which comprises resisting the 7. The method of correcting curved print- I ing plates which comprises resisting the curved printing surface of the printing plate by a curved resisting surface and appl ing progressively acting spaced-apart ro ling pressure upon the rear faceof said printing plate with pressure overcoming the resistance to local fiexure in theprinting surface of said printing plate whereby to locate all printing portions of said' printing surface in a predetermined curved surface.

, 8. The method of correcting curved printing plates which comprises resisting the curved printing surface of the printing plate by a curved resisting surface and applying progressively acting spaced-apart alternating rolling pressure upon the rear face of said printing plate with ressure overcoming the resistances to local exure in the printing surface of said printing plate whereby to locate all printing portions of said rintifng surface in a predetermined curve surace. I

9. The method of correcting curved printing plates which comprises resisting the curved printing surface of the printing plate by a relatively unyielding curved face all portions whereof are in the same surface and applying rolling compression by rolling surfaces having indentations upon the rear face of said printing plate in spaced-apart alternatin curved paths progressing across said rear ace of said printing plate in close relations and with pressure compressing the body of said printing plate and pressing all portions of said printing surface into the same curved surface as determined by printing pressures.

In testimony whereof, I have hereunto signed my name.

LESLIE W. GLAYBOURN'.

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