US 3682079 A
A lithographic plate automatic developing machine having a plurality of feed rollers for conveying on exposed lithographic plate and a rotating and oscillating cylindrical member having a flexible peripheral surface which contacts the exposed surface of the lithographic plate for applying a developing solution thereto and for building up an image thereon. Rinsing means are provided for washing the developing solution from the plate and a gumming solution is applied to the developed surface by way of the periphery of one of the feed rollers sequentially engaging the solution and applying it to the developed surface prior to feeding the developed plate from the machine.
Claims available in
Description (OCR text may contain errors)
United States Patent Casson, Jr. a [451 Aug. 8, 1972 [s41 AUTOMATIC LITHOGRAPHIC PLATE. 3,313,913 4/1967 Limberger ..95/89 x DEVELOPING MACHINE 3,448,720 6/1969 Graham ..118/314 x v 1 Y  in emor gxg g t fm' 1 Alrpark Primary Examiner-John M. l-loran Assistant Examiner-Alan A. Mathews [221 Ned: Alml 1969 AttorneyShlesinger, Arkwright & Garvey  Appl. No.: 814,566
 ABSTRACT  US. Cl. ..95/89 R, 95/94 R A lithographic plate automatic developing machine  Int. Cl. ..G03d 5/06 having a plurality of feed rollers for conveying on ex-  Field of Search ....95/89, 94; 118/240, 241, 242; posed lithographic plate and a rotating and oscillating 101/463 cylindrical member having a flexible peripheral surface which contacts the exposed surface of the litho- Referemes Cited graphic plate for applying a developing solution thereto and for building up an image thereon. Rinsing UNITED STATES PATENTS means are provided for washing the developing solu 773,607 l l/ 1904 Wade ..l18/240 tion from the plate and a gumrning solution is applied 1,651,627 l2/ 1927 Parks ..118/241 X to th developed surface by way of the periphery of Morse X one of the feed rollers sequentially engaging the solu- Murck 2 tion and to the developed surface prior to Cqughlln feeding the developed plate from the machine 2,577,793 12/ 1951 Miller ..118/240 X 3,218,950 11/1965 Liedl et al ..95/94 X 2 Clailm, 12 Drawing Figures Feed S1o1ion Deve|oping Sluliuu Raisin Station uumming Station" 24 I PATENTEDws 81972 3.682.079
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Dev. Member 250 (7* Fly. 4 INVENTOR 252 "N0 Edward A.Cosson, Jr.
Feed Reverse BY W? f4 ATTORNEYS PATENTEMH I912 3.682.079 sum 2 BF 7 INVENIOR Edward A. Cosson, Jr.
7 7 WW% ATTORNEYS I PATENTEDAuc 8 I972 SHEET 3 [IF 7 ATTORNEYS Edward A.Cosson, Jr.
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P ATENTEDAus a 1972 SHEET 4 OF 7 Edward A.Cusson, Jr.
BY WW/% ATTORNEY PAIENTEDAus 8 I972 SHEET 5 BF 7 Edward A.Cosson, Jr.
O mmm T265 msEEnwvTlcozoa oc c T 9.50650 .8105 ummm WW/fm ATTORNEYS PATENTEDAus 8 I912 SHEET 6 or 7 INVENTOR Edward A.Cc|sson, Jr.
E i I I i =i iv 00. om h L1 09 om .Pk 09 m ATTORNEYS PATENTEDAus a 2972 SHEET 7 BF 7 INVENTOR Edward A.Cosson, Jr.
ATTORNEYS 1 AUTOMATIC LITHOGRAPHIC PLATE DEVELOPING MACHINE BACKGROUND OF THE INVENTION Diazo sensitized lithographic plates which have been exposed through either a negative or positive film have heretofore been developed by pouring developing solution on the plate and working up the image and nonimage areas manually by'rubbingwith a sponge. This is followed by washing the plate and applying a gumming solution to the exposed surface by hand. The development of plates in this manner is a tedious and time-consuming operation requiring the services of a skilled person.
Automatic developing machines for lithographic plates have recently appeared on the market. Such machines have been designed to permit developing an exposed lithographic plate and working up the image and the non-image areas thereof automatically by mechanical means so as to no longer require the ser vices of a skilled person in processing the plates.
. Known automatic developing machines are provided with means feeding an exposed lithographic plate through an enclosure, generally by way of a conveyor belt supporting the plate. A developing solution is sprayed on the exposed surface of the plate and working up" of theimage and non-image areas is errected by means of a plurality of rotating cylindrical sponges having substantially vertical axes of rotation. The sponges are lowered by hand from a position out of contact with the exposed face of plate to a position in contact with the exposed face. The sponges, generally three to nine in number, are adapted to rub the exposed face of the plate. If any comer of the plate is not perfectly flat, one of the rotating sponges can easily catch the corner of the plate and severely bend the plate corner or edge to such degree that the plate may be caused to have its leading edge move upwards toward the mechanical drive of the sponges, thus jamming the machine and damaging the plate which must then be scrapped. Furthermore, the rotating sponges catching the comers and the edges of the plate are frequently ripped and torn, thus requiring replacement of the sponges. Such machines require repeated pressure adjustment of the sponges, manual raising and lowering of the sponge spindles for each plate developed, and frequent adjustment for changes in plate thickness and width size. The developing solution spray nozzles frequently clog and require repeated cleaning. Developing solution is thrown all over the interior of the machine, thus requiring frequent cleaning. Leakage of oil and other contaminant on the surface on the exposed face of the lithographic plate cause deterioration of the image.
Other prior art developing machines for lithographic plates are provided with a rotating cylindrical sponge having an axis of rotation parallel to the plane of the plate. The plate is fed through the machine by way of a conveyor belt with the exposed face of the plate disposed on top, developer is supplied to the plate surface by means of nozzles and the periphery of the rotating cylindrical sponge is engaged with the plate exposed face for working up the image and non-image areas. The developed image is often of poor quality and includes numerous streaks, some of which are caused by the separations between the sponge sections and others are caused by defects or worn spots in the sponge sections always rubbing the plate surface at the same lateral location. The rotating sponge tends to catch the edge of the plate and the plate may be bent or deteriorated as a result of passing through the machine.
The present invention, by contrast, provides a developing machine for lithographic plates which is fully automatic in use, requires little care, and can be operated by relatively unskilled persons. The mechanical drive portion of the machines are located exteriorly to the machine such that no contamination by oil or other contaminants can cause deterioration of the developed image. The present invention permits to eliminate many of the disadvantages of prior art developing machines for lithographic plates by providing at'all time positive holding of the exposed plate by means of resilient'feed rolls of an appropriate hardness to positively feed the processed plate through the machine, exposed face down, by providing means for impregnating a cylindrical sponge with a developing solution and by rotating the sponge along an axis generally parallel to the surface of the plate, and by engaging the periphery of the sponge, while in rotation, with the exposed face of the plates so as to work up the image and non-image areas. The sponge is sup ported by a spindle or shaft axially oscillated such that the sponge periphery is laterally translated relatively to the plate surface so as to prevent the formation of streaks on the worked up image thereon. The direction of rotation of the cylindrical sponge is such as to prevent catching of the comers and of the leading edge of the plate, and the rotation of the sponge is automatically stopped before the trailing edge of the plate is translated to a position wherein the peripheral surface of the sponge, due to the direction of rotation thereof, could have a chance of catching said trailing edge of theplate.
SUMMARY OF THE INVENTION The presentinvention therefore relates to an automatic developing machine for lithographic plates which include positive feeding means for translating an exposed lithographic plate through an enclosure, a cylindrical flexible rotating member such as a shaft covered with a sponge material peripherally engageable with the exposed face of the plate for rubbing such face for working up the image and non-image areas thereof, and with means for automatically rinsing and gumming the surface of the plate after an image has been worked up thereon.
It is therefore an object of this invention to provide a machine for automatically, efficiently and rapidly developing lithographic plates. 7
Another object is to provide an automatic lithographic developing machine, wherein the developing solution is mechanically applied to the lithographic plate by a rotary rubbing member which rotates and oscillates simultaneously, the periphery of the rubbing member being impregnated with a developing solution and engaging the plate surface to work up the image on the latter.
A further object is to provide a machine of the character described, wherein the plate to be developed is carried by feed rollers to a developing station where the image on the plate is worked up, followed by rinsing of the developing solution from the plate and an application of a gumming solution to the exposed surface thereof, the developing operation being carried out in a continuous process within the machine, following which the completely developed plate is fed therefrom.
A still further object is to provide a developing machine capable of accomodating lithographic plates of various widths and which may be operated by an unskilled person.
Other objects will be manifest from the following description of the invention taken in conjunction with the accompanying drawings. Y
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of an example of developing machine according to the present invention with parts omitted for clarity;
FIG. 2 is a front elevational view of the same;
FIG. 3 is a plan view of the example of machine of the present invention;
FIG. 4 is a front elevational view taken along the lines 4-4 of FIG. 1 and showing to advantage the control panel forming a part of the present invention;
FIG. 5 is a side elevational view taken along the lines 5-5 of FIG. 2, looking in the direction of the arrows;
FIG. 6 is a side elevational view taken along the line 66 of FIG. 2, looking in the direction of the arrows;
FIG. 7 is a sectional view taken along the line 77 of FIG. 3, looking in the direction of the arrows;
FIG. 8 is a sectional view taken along the line 8-8 of FIG. 5, looking in the direction of the arrows, and showing to advantage the upper feed roll drive;
FIG. 9 is a sectional view taken along the lines 9-9 of FIG. 5, looking in the direction of the arrows; showing to advantage the lower feed roll drive;
FIG. 10 is a sectional viewtaken along the line 10 10 of FIG. 6, looking in the direction of the arrows;
FIG. 11 is a sectional view taken along the line 11- 1 1 of FIG. 10, looking in the direction of the arrows; and
FIG. 12 is a fragmentary perspective view of a mop sponge forming a part of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT The illustrated example of an automatic lithographic plate developing machine according to the present in vention includes a frame supported by legs 22, a platform 24 being positioned between the legs near the Rearwardly of rollers 66, 68, 70 and 72 are additional rollers 78', 80 and 82 having shaft portions 84, 86 and 88 which are rotatably supported in bearings exteriorly of the walls of frame 20. The upper feed roll assembly lies in a substantially horizontal plane above the lower feed rolls, the lithographic plate to be developed being fed exposed face down between the upper and lower feed roll assemblies to conduct the same through the machine.
In order to effect adjustment of the pressure on the upper feed rollers to effect optimum force on the lithographic plate, each of the upper feed rollers is floatingly mounted by means of bearings 90 through which each terminal of the roller shaft extends, one end of each bearing bein'g pivotally mounted to the bearing side wallof the frame or sub-frame by means of a pin 92. .A second pin 94 is diametrically opposed to pin 92 and is rotatably positioned in a loop portion 96 of a swing bolt 98. Bolt 98 is threadedly engaged through a stationary plate 100 for effecting longitudinal movement of the bolt, and consequent vertical adjustment of the rollers about point 92 as a pivot point. Adjustment of swing bolt 98 is facilitated by a hand knob 102 and a tensioning spring 104 is located between plate 100 and a collar 106 carried by the bolt periphery.
In order to drive the upper and lower drive roll assemblies, there is provided a motor 108 having a drive' shaft 110 on which is mounted a gear 112 for actuating a chain 114. As shown in FIGS. 5 and 9, chain 114 extends upwardly into engagement with an idler 116 and p then engages a sprocket gear 118 connected to the terlower extremity thereof. A control panel 26 is mounted on support means 28 attached to frame 20.
As shown to advantage in FIG. 9, there is rotatable mounted in a horizontal plane within frame 20 a lower feed roll assembly comprising a plurality of feed rollers of suitable construction designated 30, 32, 36, 38, 40 and 42 having shaft portions 44, 46, 50, 52, 54 and 56 respectively the terminals of which are reduced and adjustably mounted in suitable bearing members exteriorly of the machine, in a manner to be hereinafter described.
Above the lower feed roll assembly is an upper feed roll assembly (See FIG. 8) comprising rollers 58, 60, 62 and 64 having shaft portions 66, 68, and 72 which are adjustably mounted in bearings extending beyond side walls of a subframe 74, which is hingedly connected to frame 20, as indicated at 76.
minal of shaft 50. Chain 1 14 then extends rearwardly of the machine to a second sprocket 120 attached to the terminal of shaft 52 and then returns to sprocket 112. Rotation of rollers 36 and 38 is thereby effected. Shaft 50 is provided with a second sprocket 112 on which is mounted a second sprocket chain 124 which extends downwardly and forwardly into engagement with an idler sprocket 126 and then upwardly into actuating engagement with a sprocket 128 connected to a terminal of shaft 46 for rotating roller 32. A sprocket 130 is connected to and driven by sprocket 126 to which sprocket 130 is engaged and a sprocket chain 132 which extends upwardly and forwardly to a sprocket 134 is connected to aterminal of shaft 44. This eflects rotation of feed roller 30. The'rollerspreviously described are each made of, preferably, a steel shaft provided with a substantially thick sleeve-like cylindrical hollow portion made of a rubber or rubber-like material. The rubber or rubber-like material has an appropriate resiliency, neither too'hard nor too soft, so as to provide positive drive of the lithographic plate through the different stations of the machine and strong support and holding of the plate at each station, while preventing marring of the plate surfaces sandwiched between two opposed rollers. Preferably, the feed rollers have a sleeve-like cylindrical covering made of a material such as Buma- N or PVC rubber of a durometer comprised between 30 and 35.
A terminal of shaft 44 is provided with a sprocket gear 136 which is in meshing engagement with a sprocket gear 138 attached to a terminal of shaft 66 of the upper feed roll assembly for driving roller 58. A sprocket 140, to which is engaged a sprocket chain 142, extends to a sprocket 144 on shaft 68 for driving roller 60. A second sprocket 148 on shaft 68 is provided with a sprocket chain 150 which extends to actuating engagement with a sprocket 152 connected to the terminal of shaft 72 for driving roller 64. A second sprocket 154 on shaft 72 is provided with a sprocket chain 156 in engagement with a sprocket 158 on shaft 70 for rotating roller 62.
As indicated above, sprocket chain 114 is in driving engagement with sprocket 120 attached to terminal 52 of feed roller 38 to actuate the latter. A second sprocket 160 connected to shaft 52 is connected by a sprocket chain 162 to a sprocket 164 on shaft 54 of roller 40, to rotate the latter. Shaft 54 is further provided with another sprocket 166 engageable with a sprocket chain 168 which extends into driving engagement with a sprocket 170 attached to shaft 56 for rotating roller 42.
By means of the above construction, it will be seenthat all of the rollers of the lower feed roll assembly are driven and the rollers attached to the sub-frame of the upper feed roll assembly are also driven, thereby providing positive rotary forces for conveying lithographic plates through the machine.
It is a salient feature of the present invention to provide a developing assembly which is located between lower feed rolls 32 and 36. As shown in FIG. 7, lower feed rollers 30 and 32 and upper feed rollers 58 and 60 comprise a feed station for directing lithographic plates, exposed face down, internally of the machine. Beneath these rollers there is provided a pan 172 extending transversely of the machine for collecting waste fluids and directing them to a main drain 174 which extends beneath and rearwardly of frame 20.
Adjacent the feed station is a developing station which, in addition to lower roll 36 and upper roll 62 and 64 includes a rotating and oscillating rubbing member 176 having a central shaft 178 which is rotably mounted at both ends thereof externally of the side walls of the machine. Developing member 176 has an axis of rotation substantially parallel to the lithographic plate may be of any desired absorbent material capable of applying a frictional force on the plate, such as a mop sponge made of cellulose fibers, '179 wound on a core 180 as indicated in FIG. 12.
Referring to FIG. 7, the developing station further includes, in the example of the invention herein illustrated a pan 181 for the developing solution which extends forwardly and upwardly adjacent the periphery of member 176, and terminates adjacent roller 32. A drain 182 in the bottom of pan 181 is in communication with main drain 174, for draining developing solution from the pan when desired. Alternately, if so desired, the pan 182 may be used only as a drip pan for recovering developing member 176 when rotating. It has been found that a small amount of developing solution is actually required and all that is necessary is, from time to time, to impregnate the cellulose fiber sponge material of the rotating member 176 with a small amount of developing solution squirted or sprayed thereon. One such impregnation with developing solution of the rotating member 176 is, for all practical purpose, sufficient for processing a substantial number of lithographic plates in succession. Additionally, the structure of the machine may be modified by providing a spray ramp, not shown, provided with a plurality of non-clogging spray nozzles for, from time to time, impregnating the developing member 176 with an appropriate developing solution.
In order to effect vertical adjustment of member 176, each terminal of shaft 178 is journalled in a sliding block 184 which is mounted between guide rails 186. Vertical adjustment of block 184 and member 176 is effected by a hand wheel 188 which is connected to a gear box 190. This efi'ects longitudinal movement of a shaft 192 engaged with a bushing 193 of guide block 184, for producing vertical movement thereof in either direction.
In order to produce simultaneous vertical movement of both guide blocks, hand wheel 188 is connected to a shaft 194 extending transversely beneath frame 20 for operative engagement with shaft 192 on the opposite side of the machine from hand wheel 188.
It will be noted from FIGS. 10 and 11 that at the side of the machine remote from hand wheel 188, guide block 184 is provided with a cylindrical sleeve bearing 195 through which shaft 178 passes, the sleeve bearing pemiitting longitudinal as well as rotational movement of the shaft therein. Bearing 195 is extended and enlarged at 196 and is provided with an insert 198, which is secured to sleeve bearing 196 by suitable means 200. At the locus of insert 198, shaft 178 is reduced, as indicated at 179, which reduced portion is fixed to insert 198. A drive pulley 202 having a drive belt 204 is fixed to sleeve portion 196 and insert 198 for effecting rotational movement, of shaft 178. Belt 204 is energized by motor 206 having a drive shaft 208, on which is mounted a pulley 210 in actuating engagement with drive belt 204.
In spaced relationship to pulley 202, and separated therefrom by a spacer sleeve 212, is an oscillating unit comprising a track cam 214 fixedly mounted on the terminal of shaft 178, which track cam is of generally cylindrical shape. The periphery of track cam 214 is provided with a guide way 216 which forms an angular annulus in the track cam periphery. Terminal bearings are indicated at 217.
Beneath track cam 214, frame 20 is extended as indicated at 218, (See FIGS. 6 and 10), on which extensions are mounted a pair of spaced vertical guide pins 220, the upper portions of which are connected by a transverse guide block 222 subjacent guide pins 220. At the locus of guide pins 220 are stops 224. Convolute springs226 extend between stops 224 and extensions 218.
Intermediate its length, guide block 222 is provided with an upwardly extending cam follower 228 adapted for riding in guide way 216 of track cam 214. Therefore, upon rotation of track cam 214, a resultant oscillating movement of the cam, shaft 178 and member 178 occurs by virtue of the extension of guide way 1 16 from one side of the cam to the other and back again, to apply a multi-directional rubbing force i.e. rotary and oscillating, on the plate to be developed such as to prevent the formation of streaks on the surface of the plate.
Referring now to FIG. 7, after a plate passes the developing station, it is fed to a rinsing station comprising opposed rollers 38, 78 and rollers 40, 80. Between the opposed rollers is a vertical water pipe 230 to which are connected an upper spray pipe 232 for directing a rinsing spray into the top surface of the plate, and a lower transverse pipe 234 for directing spray upwardly against the lower surface of the plate. Upper spray pipe 232 is provided with an arcuate spray shield 235. A pan 236 is mounted on the frame below the rollers into which the rinse water gravitates and is carried away by a drain 238 to main drain 174. Splash baffles 240 and 242 are mounted on the top of frame 20 for retaining the water within the rinse station.
Beyond the rinsing station, there is provided a gumming section which includes opposed rollers 42 and 82, the former being located within a trough 244 in which is placed a gumming solution for application to the developed surface of the plate. It will be apparent that as roller 42 rotates within the trough it picks up the gumming solution and uniformly applies it to the face of the lithographic plate which it contacts prior to emission of the developed plate from the machine. A waste pipe 246 and a valve 248 are provided for removing the gumming solution from the trough.
Operation of the machine of the present invention is controlled by an operator who operates control panel 24, which control panel includes a start button 250 which actuates motors 108 and 206. A feed reverse button 252 is provided for use anytime it is desired to reverse the movement of the lithographic plate within the machine. A stop button 254 halts the machine operation.
In addition to the above, there is provision in the machine of the present invention forcontrolling the operation of development member 176 by means of a dial 256 which may be turned to the manual position for effecting actuation of the member as desired, or the dial may be moved to the automatic position.
When in the automatic position, operation of developing member 176 is controlled by elements 258 and 260 forming an felectric eye assembly including a photocell and an incandescent lamp which are in OPERATION In the use of the machine of the present invention, knobs 102 may be adjusted if necessary to effect vertical movement of the upper feed rollers until the proper pressure is exerted on the lower feed rollers to effect optimum movement of the lithographic plates through the machine. 7
The lithographic plate is fed into the machine between rollers 90 and 92, exposed face down, following which it is fed between elements 258 and 260 of the photoelectric cell assembly to actuate rubbing member 176, which then rotates andoscillates transversely while at the same time picking up developing solution as it rotates through the trough of pan 181. As the lithd graphic plate proceeds between rubbing member 176 and roller 62, the developing solution is uniformly appliedto the entire surface thereof and uniform pressure is applied to the plate surface to work up the image over the entire surface area of the plate.
The plate is then fed between rolls 36 and 64 to complete the developing phase of the operation following which it enters the rinsing station where, after passing between rollers 38 and 78, it passes between upper and lower spray pipes 232 and 234 which spray a rinse water on the entire surface of both faces of the plate. The plate is next fed between rollers 40 and 80 into the gumming station where a gumming solution picked up by roller 42 as it passes through trough 244, is applied uniformly to the lower surface of the plate. After this, the plate is fed from the machine and ready for use.
With the machine of the present invention, no human intervention is necessary during any part of the operational cycle, other then to operate this machine. The developing solution is applied uniformly to each plate fed through the machine and the same multidirectional rotary and oscillating pressure is. applied to the plate surface for working up the image on the plate. The machine may of any desired width in order to accomodate a variety of plate sizes.
The machine of the present invention further obviates the tedious job of manually working up" the image on the plate, rinsing it off then applying a gumming solution thereto, but also, because it is a continuous mechanical process, treats each plate in the lying in the path of movement of the lithographic plate for engaging the exposed face thereof,
g. means for applying a developing solution to the peripheralportion of said cylindrical member,
h. means for rotating said cylindrical member around an substantially parallel to the lithographic plate for applying and frictionally working the developing solution into the exposed face of the lithographic plate, i. means for effecting axial oscillation of said cylindrical member whereby multi-directional movement of said cylindrical member is effective to work up an image on the plate, and
j. means for applying a gumming solution to the developed surface of the plate,
k. said means for applying the gumming solution comprising a trough mounted within said frame, 1. a cylindrical member rotatably mounted on said frame, m. a portion of the cylindrical member periphery being within said trough and in contact with the gumming solution,
n. another portion of the cylindrical member periphery lying in the path of movement of the ithographic plate for applying a gumming solution coating to the lithographic plate surface; and
0. power means for rotating said gumming solution cylindrical member to progressively apply gumming solution to different peripheral portions thereof. 7 2. An automatic lithographic plate developing machine comprising:
a. a frame, b. container means mounted on said frame, c. conveying means for feeding through the container means a lithographic plate having an exposed face, d. said conveying means including a series of rollers comprising a lower feed drive, e. a series of rollers comprising an upper feed drive, f. said upper feed drive rollers being above, and in opposed relation to, the lower feed drive rollers, g. means for vertically adjusting rollers of said upper feed drive, b. said means for vertically adjusting the rollers of said upper feed drive comprising bearings for said cylindrical member pivotally connected at one 10 side to said frame,
i. a swing bolt threadedly engaged with said frame above each bearing,
j. the lower terminal of said swing bolt being engaged with the opposite side of each of said bearings about the pivotal connection to said frame, for effecting vertical movement of said bearings and the rollers extending therebetween,
k. means for actuating said conveying means,
1. a cylindrical member mounted within said frame,
m. a peripheral portion of said cylindrical member lying in the path of movement of the lithographic plate for engaging the exposed face thereof,
n. means for applying a developing solution to the peripheral portion of said cylindrical member,
0. means for rotating said cylindrical member around an axis substantially parallel to the lithographic plate for applying and frictionally working the developing solution into the exposed face of the lithographic plate, and
p. means for effecting axial oscillation of said cylindrical member whereby multi-directional movement of said cylindrical is effected to work up" an image on the plate.