US1438589A - Machine for and method of making printing plates - Google Patents

Description

C. W. FETHEROLF.

MACHINE FOR AND METHOD OF MAKING PRINTING PLATES.

APPLICATION Hug-0 1o, 1g21.

" Patented Dec. 12, 1922.

2 5HEETSSHEET l.

INVENTOR.

A TTORNEY 5 C. W. FETHEROLF.

MACHINE FOR AND METHOD OF MAKING PRINTING PLATES. APPLICATION FILED OCT-10, 1921.

1,438,589, I Patented Dec. 12, 1922.

2 SHEETS-SHEET 2.

" ATTORNEYS ti t i were 2 ug-=15 EHARLES w. FETHEROLF, or woscns'rna, i inssncnusnrrs.

MACHINE FOR AND METHOD OF MAKING PRINTING PLATES.

I Application filed October 10, 1921. Serial No. 506,668.

1 all whom it may concern: l Fig. 8 is'a'side view of a part of the ma- Be it known that 1, CHARLES Vl Fn'rnnnch ne; I cm, a citizen of the United States, residing Fig. 4 1s a sectional view on an enlarged at l l orcester, in the county of Worcester scale on the line 44 of Fig. 2; 5 and State of Massachusetts, have invented Fig. 5 is an enlargedsectional view of a a new and useful hilachine tor and Method metal printing plate formed in accordance of Making Printing; Plates, o'l which the with this invention and illustrating the cutfollowingis a specification. H ting point therein; and

This invention relates to the making of, Fig. is a view of a picture divided into 10 plates for printing purposes and, although zones for use with this inventirm. capable of use for engraving on wood blocks in carrying out the method herein disand other kinds of materials, it is particuclosed by the machine shown in the drawlarly adapted for the making of half tone ings, I start either with a drawing, photolates on etal, graph, or picture which is to be reproduced 15 The principal objects of the invention are or aved, or I provide a projectoscope to provide a machine and a method of en 10 ML-{ll may be of any ordinary type and grieving); by which a very large percentage will throw its light from an object placed of the cost of making halt tone plates, partherein and reflect it on a ground glass 11 ticularly tornewspaper work, will be elimiso as to provide a picture. 12 on this plate. 20 nated and by which plates can he produced ll an instrument of that character is not without the use of expensive apparatus, used, the photograph, drawing or other picchemicals, or technically tanned workers; ture which is to be reproduced, is placed in to greatly increase their adaptability to vathe location occupied by this picture 12. In rious publications; to provide means whereeither case the figure to be reproduced is by engraving can be made directly from an located in convenient position, preferably object without first producing a fixed pic on a shelf 13 projecting from a base 14 ture of it of any kind; to provide for :formwhich constitutes the standard for supporting the cuts in a plate with the desired ing the machine, I depth so as to secure the desired tones in Also mounted on this standard it is a 30 such a way that the samewill be capableof table 15 having a supporting block 16 held being modified within the judgment of the in position by dowels 1.6? so as to permit it operator as his taste and artistic ability may to he turned at right angles'after parallel dictate so that they can be employed to good cuts have been made over it in one direcadvantage in making reproductions; to protion. This is provided with a rest 17 at one vide a machine which, while making use of side and with a pair of adjustingscrcws 18 well known mechanical expedients, will at the other which are designed to clampguide the cutting blade in parallel lines and between them a plate QOwhich is to conprovide means whereby the depth of the stltutc the print ng plate. When a half out can be regulated oythe operator as tone plate is to be produced this printing 40 stated above, and to provide an improved plate is located in the position shown in form of printing: plate having grooves of F l, in which it is diagonally placed on such shape that there will be no danger or" the table. The purpose of this will be unan intended white spot printing in black derstood by those skilled in the art and will or making a blur. l be explained later. 4.5 The invention also involves improvements The plate 20 preferably is termed in details of construction and various comstereotype metal or some other soft combinations of parts of the machine itself. position of lead, tin and antimony or other Reference is to be had to the accompanymetals in proper proportion. his in itself in drawings, in wh1chis an important improvement constituting a 50 l ig. 1 is a plan of machine constructed feature of thisinvention because a plate o'l in accordance with this invention, showing such sottmetal can be engraved by this it in the act of reproducing or engraving a machine in avery convenient manner and picture or the like on a type high metal without the employment of any exhausting block; force. a I 55 Fig. 2 is an end view of the same; On a bracket 21 onthe table 15 l place a vertical pivot stud 22 to which is pivoted one arm 23 of a pantograph. This has the usual other arms 24, 25 and 26. The arms 24 and 26 are permanently pivoted together by a stud 27. Three other studs 28 are used to pivot the other arms together in the form of a parallelogram using the perforations 29 with which the several arms are provided to control both the shape and size of the reproduction, as is well understood in that art. The arm 25 is shown as projecting beyond the arm 24 and beyond its pivot 28 and provided with a stylus 30. This stylus can be located at a short distance from the pivot pin or concentric with it if desired. This stylus does not produce any marks but is used to trace the details of the picture.

At the place at which the two arms 24 and 26 are permanently pivoted, there is provided a head 33 having a cutting or engrav ing tool 34 projecting down from it at an inclination. The head 33 with the blade 34 is designed to be moved up and down by a thumb screw 35. The threaded lower end of this screw extends into a slide 36 below. This is employed to raise and lower the blade 35 to cause it to make a deeper or shallower cut in the surface of the plate 20. The depth is indicated by a center point or indicator head 33 and a graduated wheel 38 fixed on the thumb screw. This wheel is provided with divisions on its circumference marked off numerically or otherwise. have shown it as having six marks besides the. zero. when it is turned around so that the zero point is in registration with the indicator 37, the blade 34 will not cut into the surface of the plate 20, but when it is turnedto any other positions, the blade will cut into different depths as will be obvious. The slide 36 has a dove-tailed bottom guiding portion 39 which slides along in a clove tailed guide 40.

On the end of the machine is a ratchet 5 wheel 41 fixed to a screw shaft 42 journ'aled below the table. .This wheel has a handle or crank 43 for operating it. The rotation.

of this ratchet advances a yoke 44 through which the screw passes. The ends of the yoke pass upwardly machine and carry the ends of the guide 40. Thus, the ratchet wheel slides the guide with head over the plate to be engraved. The

guide works in ways 45 on the side edges of the table 15. From what has been said, it will be obvious that the ratchet wheel can be rotated by hand. I have provided a spring pawl 47 locking the ratchet wheel automatically also an operating pawl 48.

Thisoperating pawl has a counterbalance 49 for keeping it in contact With lthe teeth and is pivotally mounted on a bell crank 50 which is provided with a link 51 extendin'g I Every time the pedal is depressed the wheel will down and supporting a pedal 52.

a slot .in a'bracket 54 on the table.

on opposite sides of the be rotated one tooth or more according to its adjustment. The adjustment is secured by means of a screw 53 threaded into the bell crank 50 and passing loosely through This screw has a head 55 and a locking nut 56. This nut secures it in adjusted position on the bell crank and the nut and head together limit the motion of the crank on its pivot.

The engraving tool 34 is so shaped as to give considerable more depth to the cut out portions of the engraving plate 20 than is possible on half tones as atpresent produced. For this purpose it is provided with two lowercutting edges 56, making equal angles with a vertical line atthe center preferably. The angle between the two edges preferably is about It will be seen that this blade will cut in to the plate 20 to any desired depth to form V-shaped grooves 57. These grooves may be only slight as shown at the extreme right and left hand of Fig. 5, or they can be deeper. It is the turning of the head 38 that regulates the depth of the cut and consequently the width of the uncut surface of the plate between grooves 58. ,It will be observed, therefore, that it is the depth of the twoadjacentcuts that regulates the widthof theprinting surface 58. These printing surfaces, as is well known, constitute the points or lines which receive the ink and impart theimpression in printing. Just'at the right of the cutting I blade in Fig. 5, I have shown two of them which come to a point and therefore produceonly a line or dot while farther to the right I have shown one numbered 59 which terminates belowthe surface of the plate 7,

and consequently will not-make any impression. Inother words," at that point a blank or white space is provided the width of two cuts.

The method of producing. a half tone plate by this invention is as follows:

A'picture or tracing in outline l2 provided as above specifiedis plotted offinto shading areas, each area numbered from 1 to 6 to correspond to 'the depth of shading existing in said areas. The number 1 would I be applied to all very dark or black shaded areas, number 2 to lightershadedv areas,

9 number 3 to a still lighter shade and so on. These areas are outlined either by grapl1iv cally marking on the picture 12 by a pencil or the like or by simply being kept in the L mind of, the operator after he is sufficientlyexperienced. I have shown them marked out on thedrawing as a new operator would have to employ them. They fare given their respective numbers from l to B, 1 showing the-blackest lines with shallowe st cuts and 6 the 'faintestlines with deepest cuts. The plate 20 to be engraved is placed in position diagonally as indicated in Fig. l and the guide located at the upper corner of it. The operator then takes hold of the thumb screw 35 with one hand and the knurled knob 31 with the other hand and draws the frame 38 with its cuttin tool 3% across the plate guided by the guide 40. in doing so, he turns the thumb nut 35 so as to bring any desired one of the numerals into registration with the indicator 3? corresponding to'the shading area which the stylus 1-30 is passing over on the picture. For example, near the top of the picture the stylus will. first encounter a pure white spot. The thumb nut is turned so that the numeral 6 registers with the point 37 and the head and cutting tool is started across the guide and cuts a deep groove. The stylus next enters an area marked 52 on the drawing and the thumb nut is immediately turned baclt to the point 2. Now the blade 34- still cuts into the printing plate but not so deeply. The thumb nut is kept at that point until the stylus 30 reaches a lighter spot when it will be shifted accordingly to correspond to the area as numbered on the figure. When this line is completed. the cutting blade is lifted either by hand or automatically as may be desired and the head moved back to the left. Now the operator steps on the pedal 52 which shifts the hand wheel 41,

around one or more notches and advances the guide 40 the width of one complete line on the metal printing. This also draws the stylus 30 down a proportionate distance and the operator then again goes through the process above described.

After the whole plate has been engraved with parallel lines making an angle of, say 45, with the horizontal in this way, the supporting block 16 turned quarter way around and the process repeated it a halt tone plate is desired. This produces a plate in which two series of lines run across it diagonally and at right angles to each other.

The gradations or shading of the original picture are reproduced on the plate by variation in the depth and width of the lines engraved thereon but this is not done auto matically. The operator has a chance to introduce variations according to his knowledge of the art of printing by half tone plates or according to his artistic ability.

t will be understood that the invention is not limited to halt tone plates, as plates can be made in which there is only one series 01"? parallel engraved lines and those can be made at the angle above specified or any other angle or vertically as may be desired.

It will be seen, therefore, that the necessity for taking a photograph of some objects that are to be reproduced by means of a half tone plate is done away with by this method and that the use of an expensive photographing outfit and use of chemicals in making the half tone plate itself are also eliminated. This expands the usefulness of i an indistinct photograph which would not produce a good half tone plate by the old methods can be used as the base tor a practical illustration even for newspaper work. This is a very important advantage because many photographs and othe pictures cannot be successfully reproduced by the halt tone method on account o'f'the large hlaclr or blllITeCi or indistinct surfaces which they present.

The plate itself is an important element of the invention because of the ease with which variations in shading not shown on copy or object to be reproduced can be pro-- vided. .h large white or blank surface care not possibly be printed black or blur on ad count 'otthe projection of a soft inking roller on its recessed shallow I surfaces as has been the case heretofore. it the roller has descended in the blank field, nothing will be printed except fine sharp points. l

Although g l have illustrated and describei'l only a single embodiment of the invention and shown details of a single machine fo carryingit out, ll. am aware oi? the tact that many modifications can be made therein Without departing from the scope of the invention expressed in the claims- There.

fore, I do not wish to be limited to all the details of construction herein shown and described but what I do claim is 1. In a machine for making printing plates, the combination of means for supporting a plate, a cutting tool, means for guiding. said-tool to engrave parallel lines on the plate, and a pantograph having a stylus at one angle for tracing the picture or configuration to be transferred, the tool being located at another angle of the pantograph.

2. In machine for making half tone plates, the combination of means for supporting a metal plate, means for engraving parallel lines in the plate, and a pantograph having a stylustor tracing the picture or configuration to be transferred, with means for guiding said engraving means to move along parallel lines, and means for moving said guide transversely to its length by a step by step motion.

3. In a device for reproducing a picture or the like on a printing plate, the combination with a pantograph having a stylus adapted to be moved over the shape to be reproduced and a cutting tool for acting on the plate, on. a guide for confining the motion of said cutting tool to parallel movements. I

4;. In a device for reproducing a picture llO or the like on a printing plate, the combination with a pantograph having a stylus adapted to be moved over the shape to be reproduced and a cutting tool for acting on th e plate, of means for holding the plate in fixed pos tion, a guide for said cutting tool, and means on the pantograph for regulating the depthof the cut of the cutting tool.

5. in a device for reproducing a picture or the like on half tone plate, the combination'with a pantograph having at one ana stylus adapted to he moved over the shape to be reproduced and provided at an adjacent angle with a cutting tool for acting on the plate, lli ftl'lS for holding the plate in fixed position, and a guide for said cutting tool for restricting its motions, said cutting tool having parallel cutting edges converging to a point, of means for regulating the depth which it projects below the printing surface of the printing plate.

6. In a device for reproducing a picture or the likeon a printing plate, the combination with a pantograph having a stylus adapted to be moved over the shape to be reproduced and a cutting tool for acting on the plate, said stylus and tool being located at two adjacent angles of the pantograph, and a guide for said cutting tool, of a head mounted to move along said guide but capabio of vertical motion thereon and carrying the cutting tool, and means on said head for raising it and lowering it with respect to the uide.

7. in a device for reproducing a picture printing plate, the combipnntograph having a stylus V with cutting tool for act- 're plate, means for holding the plate Len position, a guide, a slide on sald or the like on on with a in f guide carrying said cutting tool, a head mounted to move with said slide but capable of vertical motion thereon, a screw on sai head for raising it and lowering it with respect to the slide, said screw having a circular head provided with graduations, and a fixed center point on the head for indicating the elevation of the tool by its registration with the graduations.

8. In a machine for making half tone plates, the combination of means for supporting a plate, means for engraving parallel lines in the plate, and a pantograph havi"-"' a stylus for tracing the picture or configuration to he transferred and a cutting tool for cutting into the plate, with means onhniins w. rn'rnnnorir.

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