US905155A - Method of making metallic printing-plates. - Google Patents

Description

4J. o. DE WOLF. NnTHonoF MAKING MBTALLIO PRINTING PLATES,

5i/venziontZO 70m ,Ze 0% J. o. DE WOLF. 4METHOUOI MAKING METALLIC PRINTING PLATES.

`APPLIUA'LION FILED JULYVlB, 1906.

Joa/n/ J. o. DE WOLF. METHOD l015' MAKING METALLIC .TRINTING PLATES.

n APPLICATION VFILED JULY 18, 1906.

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Patented Dec. 1; 190s.

ness is much more extensive.

JOHN O. DE WOLF,` CAMBRIDGE, MASSACHUSETTS.

- Specification ofLetters Batent.

Patented Dec. 1, 1908.

y, `Applicationled. July 18, 1906. y Serial No. 326,713.

To all whom it may. concern:

e it known that I, JOHN O. DE WOLF, a citizenl of the United States, residing at Cambridge, in the county of Middlesex and State of Massachusetts, have invented an Improvement in Methods of Making Metallic Printing-Plates, of which the following description, in connection with the accompanying drawings, is a specification, like numerals on the drawings representing like parts.

The object of my invention is primarily to save time in making printing plates for the modern newspaper oce, although it will be understood that its range of useful- Besides `this primary object, I accomplish accuracy, neatness, economy and various other'advantages, which will appear in the course of the more detailed description.

In modern newspaper work byv far the most important itemis to save'timye in getting out the printed page, and accordingly every energy and facility of the entire plant, regardless of expense are commonly bent to the oneobject of speed or economy of time; and as at present practicedv the most aggravating delay usually occurs rin the stereotyping room. It is customary now first to set the type with a linotypeV machine, then make a papier mache matrix therefromA and when the latter has hardened, bend it to the proper curvature within a mold or casting box, clamp it in place, closingthe4 casting box, and then pour the molten metal. After the latter has cooled sufciently to permit of opening the mold, the casting box is opened, the matrix is unlocked and is then stripped off. The stereotyped platey is next taken out, or, in some cases, both the plate and matrix are removed together and-afterwards separated. Then the stereotype plate isfnished, this process usually consisting of removing the surplus metal at the edgesand ends, properly finishing the same so that they will lit on the cylinderA of the printing press, and finally theback of the plate is shaved to a true form. The exact order of these operations varies somewhat, but the above sets forth with practical correctness the operations and amount of work commonly employed. It will be seen that time is wasted at each'operation in waiting for the completion of one part ofthe process before commencing the next part and that also much time is lost in `waiting for `the metal to cool and inshavingv the backto fit the cylinder, etc. Accordingly it is my object to save all this wasted time.

rlfhe present application relates to my new method, only sufficient apparatus being shown for properly presenting the method, the' apparatus and article herein set forth beingexpressly reserved for separate applications. In the first place, I aim to use less metal and thus obtain in less time a properly solidified plate. `In the next place I ,maintain a. molten or plastic condition of the metal at a given locality only, and progressively shift said locality or region over the matrix until the entire printing surface has been formed. Preferably this forming region or heated locality and application of the heated metal in such a condition as to be properly` impressed by the matrix progresses `evenly `and continuously'from one edge of the matrix to the other, and I also prefer to employ molten metal for the purpose. In the third place I gain time by performing, `previous to the setting of the type or forming the printing face, as much as possible of the necessary preparation of the back and edges of the plate, it being understood that delay prior to the setting of `the type is unimportant, the need of haste occurring after the news has beenset in type. Fourthly, I not only perform the operations progressively, as above mentioned, but I perform simultaneously some or all of the operations. v

In the most complete `embodiment of my invention I bring together progressively the moldable metal z'. e. the stereotype metal rendered impressionable by heat, and the matrix inthe presence of a chilling medium, so that the metal, either molten or semimolten, obtains its form or type impression from the matrix along a progressive line, or narrow region, and is at once caused to set. vIn other words, the molding or impressing of the printing plate and cooling or setting of the metal both take place along a narrow region or line progressively from one side of the plate to the other. In this connection I prefer to employ as thin a layer of metal as possible in order that it may receiveV shape, cool, etc., with the greatest rapidity and accuracy. This enables me to eliminate the danger of shrinking and inaccuracy which has heretofore been due to the employment of a large body of metal; and because of this feature of my inventionfI have .succeeded in eliminating entirely the necessity of shaving the back of the plate to fit the press. To this end I employ a back which has been previously prepared, having its back and edges accurately shaped beforehand, and on this previously prepared back I form a thin face of proper metal such as stereotype metal, which is progressively molded and shaped or impressed against and by the matrix and simultaneously secured to the back, set and shaped.

I piefer to accomplish the above results by means of rotary apparatus so that all the steps of the process can proceed together. To this end, in the most complete carryingout of my invention, I feed the matrix and the prepared back simultaneously forward and pour the molten metal between them, so that the three come together simultaneously and are immediately brought under the influence of a water acket or other cooling means which instantly brings the metal .to a plastic or iinpi'essioiiable condition, and,

having progressed a sufficient distance to cool sufficiently, the matrix is stripped, preferably automatically, from the united back and cast face, said stripping, cooling, pouring and moldingl all and progressively, so that when the pouring of the metal is just being finished, the stripping of the matrix has already been largely accomplished.

My method differs from what is known in the art as stereotype plate casting, in that I do not cast the plate, but, instead thereof, I deliver to a matrix progressively a line or narrow area of iinpressioiiable metal, and then instantly and permanently impress it with the desired type form or shape, whereupon it is ready, so far as its permanent type surface is concerned, to leave the matrix. The impressing is not done in freeflowing metal, as it would be impossible to leave any impress in a very fluid substance, but is done on the plastic, doughy, or very sluggishly molten metal, 2'.. c., the metal must be sufficiently soft to forced into the back and impressed at the front by the matrix, and sufficiently fixed or non-inolteii to be self-supporting and retain its shaped condition. In making a casting, the met-al flows transversely past the adjacent portion of the mold until it has filled up the mold, and then it undergoes a complicated cooling and shrinking process in the mold which finally results in a duly shrunken cast plate. My method differs radically from this casting method, as I do not flow any metal whatever transversely past the shaping surface of the matrix, but first bring the metal to an iinpressionable or partially cooled or set condition, and then be capable of being bring the metal and matrix perpendicularly together with a compressing movement which impresses the metal surface directly and permanently with its ultimate shape.

going on simultaneously I This impressing of the metal takes place along` an exceedingly narrow area which I have termed a line, and then immediately the next line or narrow area is similarly impressed, and then the next, and the next` and so on progressively until the entire plate has been formed by a continuous succession of these definite impressing movements of the matrix perpendicularly into the softened, but not liquid, metal.

My invention embodies various other important features, which will be more properly apprehended in connection with a description of the apparatus.

In the accompanying drawings I have shown a sufficient portion of my al'iparatns to enable me to explain the method clearly, it being` understood that a large mass of de,- tails are omitted to prevent confusion thereof with the description of the method.

In the drawings, Figure l is a central. longitudinal section of the simplest form ol apparatus for carrying out my invention; Fig. 2 is a similar sectional view, considerably enlarged, showing the leading` steps of the method in progress: Fig. i5 is a sectional detail similar to Fig. l, excepting that it shows the position of the parts as they are delivering the completed plate and ready to begin operations in making the next plate: Fig. 4 is a view in end elevatiiui of the parts shown in Fig. 3; 5 and (3 are longitudinal sectional views of the water-cooled portions of the apparatus, Fig. 5 being a substantially vertical section and Fig. a nearly horizontal or oblique section for showing the various cooling passages, and also showing the shape of the edges` etc., of the compound printing plate as it is being formed.

I will briefly describe the apparatus in order that the method may be more clearly understood. Mounted on a suitable base or frame l is a rotary cylinder 2 ionrnaled at 8 in. heavy uprights '-t and operated by any i convenient means as by a worm 5 and worin wheel (l driven by an electric motor or other source of power 7 shown as controlled b v a rheostat lever 8, Fig. 5, adapted to be automatically tripped by a lug 9 and latch I() or any other usual or preferred tripping mechanism for automatically stopping the machine. At the lower right-hand corner or side of the apparatus, see Fig. l, is a wateri cooled concave surface l1 for cooperating with the cylinder 2. and at the left thereof extending between the uprights lis a stripper blade or other stripping` means l2 just above a transfer table 13 pivoted at l-'lv to the base l and nornnilly held horizontal by a. latch l5 operated by a handle lt, and adapted to be tilted into the dotted position Fig. l, for the purpose of delivering the stripped matrix to a conveyer 1T so that it will be in position for the operator to retl t) place it in the Ymachine for making a separate printingplate. The matrix 18 is placed 'in illustrated Amy preferred method 'of `carrying out` my invention, in which I use metal which is actually molten, and Vaccordingly I deliver the metal 21 from a nozzle 22 of a pipe 23 through which theVV metal is pumped or otherwise delivered from a suitable source 24, herein shown as being delivered by gravity, a valve`25 controlling the inlet. 4Above the pipe 23 I preferably provide heating means, herein shown as gas jets 26 for keeping the metal in a highly fluid condition at the verypoint of delivery.

The cylinder 2 is provided with a waterjacket or suitable `cooling means 27 overv that portion which is to receive the molten metal, and at the forward end of said portion I provide a transverseblock 2S which also performs the office of a dam or stop for the metal, as will presently be explained,- over which the forward edge 29 of the matrix is adapted to be bent `and clamped automatically by any suitable mechanism, such for instance as is commonly "employed in printing presses, being herein shown as consisting of clamps 30 on arod 31, provided externally with a gear 32 operated by a toothed sector or rack 83 pivoted at 34 to the cylinder and held under downward tendency by a' spring 85 Vas well as by its own gravity, said sector rack having a shouldered engaging surface 36 for traveling on a cam ring 37 which has an incline 38 at one portion thereof and a 'sharp drop or shoulder 39 at another portion thereof,see Fig. 4. Thus when the cylinder is vjust reaching the position shown in Fig. or rather is just passing forward from the-position shown in Fig. 3, the shoulder 36 drops from the shouleieif'r and thereby gives an instant rotary movement to the clamps 30,V so that the clamping ends of the latter move in the path shown in dotted lines in Fig. 3 and operate to clamp the forward edge 29 of the matrix tightly over the block28 as shown in-Figs. 1 and 2, holding the sametightly until said part 66 reaches the part 38 of the cam ring,`

means, pipes 42 being indicated for the stationary water-jacketand axial pipes 43 being indicated yfor the cylinder jacket. The receiving surface of the cylinder is cut away `at 44 to receive the back 45 on which the type face is secured and impressed, said cutaway portion 44 coperating with the recess 40 inthe concave shaper or receiving surface. Cooperating with the recess 44 of the cylinder is a stripping mechanism, which may be of: any convenient kind, being herein shown as consisting of stripper heads 46 carried by rods 47` reciprocated by bell cranks 48 operated by a shaft 49 located in the cylinder to aline at proper intervals with a plunger 50 pivoted at 51 to a hand lever 52 pivotally mounted at53 on the frame of the machine.`l`

Let it be supposed that the machine isin the positionshown in Fig. 3. The operator takes a `back 45 which has been previously prepared so as to be of the exact shape, thickness and curvature desired, it being remembered that this previous preparation ymay have been performed at any time conthe matrix and cylinder together, the clamping dogs 30 are automatically swung from the position Fig. 3 to the clamping position Figs. l and 4, thereby clamping the matrix firmly in position so that thereafter the matrix and back move `forward together. The moment that the clamping of the matrix takes place the molten facing metal 21 is permitted to iiow. `This applies a thin face of the stereotype metal on the front of the backing, which is immediately cooled and receives proper impress from the matrix at. `the point where the back, matrix and `metal are forced together by the rotating cylinder. The moment that the impression is.; made the advance metal and adjacent parts are at once cooled by coming in contact with the water-jacketed former surface or mold 11 and the opposite water jacketed surface 'of thev cylinder. This process continues progressively, the thin metal surface being maintained softened or sluggishly molten at the initial contacting point of the back, metal and matrix, where the metal is simultaneously molded and set in permanent form at said point. This is progressively accomplished over the entire surface. I prefer to move simultaneously the matrix, metal and back, although I wish it understood that my invention includes any movement or progress of the heated impressionableregion, the cooling region and the forming region with relation to the matrix, the idea being, in its broader features, to cause the forming of the Stereotype progressively over the matrix, or in other words, to render the metal locally impressionable by heat and progressively shift said local condition over the required area of the matrix, at the same time following said locally heated condition with a localized cooling condition until the entire plate has been impressed with the matrix and cooled. Meanwhile as the plate is being thus impressed and formed along one narrow area or line thereof, the matrix and same plate are being elsewhere separated from each other. As shown, where all the parts move together, the cylinder continues rotating forward until the cam surface 3G strikes the surface 3S, which thereupon releases the clamping dogs 30 from the forward end of the matrix and the latter springs out away from the block 28 in position to be caught by the stripper blade l2, which operates automatically to remove the matrix progressively from the printing plate as the latter is being impressed and formed. The operation is continuous, without any halting at any point. When the cylinder has arrived at approximately the position shown in F ig. 3, it is automatically stopped by the tripping device 9 or any other suitable stopping mechanism, the operator pushes in the lever 52, which raises the stripper heads 46 and lifts the completed plate, to be carried to the printing press.

As the plate has been formed with an impressed surface which is thin and whose cooling` begins while it is still under prese sure, there is no resulting` uneveimess due to shrinkage or shifting in position of the metal, and hence no subsequent shaving of the plate, is required in order to bring it to the proper thickness with relation to the backing, both having been formed together as they have moved along in unison. I wish to emphasize the fact just mentioned that the impressing and cooling of the metal take place while the metal and matrix are being pressed toward each other in the act of accomplishing the impressing of the printing surface into the impressionable metal. This is one of the radically new and essential features of my invention which distinguishes itfrom what is commonly known in the art as casting. No trimming or other treatment is required, as the edges have been properly molded at the same time as the face. The back has previously been prepared with perfect accuracy and the metal is united thereto by any suitable means, as by entering holes 54 or dove-tail grooves, scorings, or any other mechanical bond, on the back 45, or the back may be of such consistency as to be slightly fused or amalgamated with the covering surface by reason of the heat of the molten met-al. I wish it understood also that my inventiou includes the union of a facing metal which is not actually melted, butA is merely softened at the local region where it is being impressed. I regard it also as broadly novel to form the composite plate with a previously prepared backing, thereby permitting all the necessarily slow back-forming part of the process to be performed. previously, when time is not vital. The need for haste all occurs after the matrix is ready, so that whatever work can be done to vards the filial finished plate previous to the impressing operation is of decided advantage in point of time. By my method, as soon as the matrix is ready, several of the finished printing plates can be prepared quickly without any halting or waiting, directly therefrom, By using a thin face of metal upon a prepared back, not only is there less molten metal to handle and to harden and no back-forming to be done, but extreme rapidity is possible in progressively uniting the face and back at 011e region while the matrix and plate are being separated at another region from the face already formed. As the molding or impressing is done progressively the metal does not have to flow as heretofore a long distance in a thin mold, and this arrangement makes it feasible to cast a thin and perfect face upon the prepared back. This method of progressive impressing and simultaneous cooling prevents the cooling strains and distortion of the finished plate which take place when a large area is cast and then the same large area` is cooled at all points at once. Also by my method I obtain exceedingly sharp detinition, which is due no doubt to the compressing of the metal while cooling, or in other words to the perpendicular impressing of the matrix into the metal when the latter is in an impressionable condition, as distinguished from being in a liquid or highly fluid, and hence, non-impressionable condition. The back may be of the same metal as the face, in which case both can be melted together again to be used over again and hence there is no waste, and in this case the weight of the plate is identical with a plate made in the old way; or a different metal maybe used for the back, as for instance, aluminum, in which case a very light plate results, an advantage of great convenience in handling when it is borne in mind that. the workman is required to handle several tons of these plates per day.

lvhile I have herein shown and described not only the method, but also the apparatus and the composite plate, I wish it understood that the present application is restricted to the method, and that the other features shown and described are reserved for other patents.

I have already mentioned various moditications, and it will be understood that I am not limited to the details hereinv set forth, as my invention may be carried out in a wide' variety of arrangements, steps, and sub-processes.

Having described my invention, what y1 claim as new and desire to secure by'Letters Patent is,

1. Themethod of making printing plates, consisting of juxtaposing the matrix and the plate material rendered locally impressionable by heat,vand progressively impressing the platematerial andshifting. said local condition over the required area until the entire plate is impressed as desired. Y

2. The method of making printing plates, consisting of juxtaposing the matrix and the plate material rendered locally iinpressionable by heat, progressively impressing the plate material and shifting said local condition over the required area until the entire' plate is impressed as desired, and progressively cooling the` said plate as it is impressed. f

3. The method of making printing plates, consisting of juxtaposing the matrix and the plate material rendered locally impressionable by heat, progressively shifting said local condition over the required area until the entire plate is impressed as desired, and meanwhile progressively stripping the matrix from the plate as it is cooled.

4. The methodl of making printing plates,

consisting of impressing the plate with the` matrix at one portion thereof, and siiniiltaneouslyv stripping the matrix from the plate at another `portion thereof.

5. The method of making printing plates, consisting of forming and impressing the plate with the matrix at one portion thereof, and simultaneously stripping the matrix from the plate at another portion thereof.

6. The method of making printing plates, consisting ofprogressively forming and impressing the plate, and progressively stripping the matrix therefrom, all as a continuons operation.

7. The method of making printing plates, consisting of previously forming a back, then applying thereto an impressionable layer and simultaneously impressing the surface thereof with the matrix.

8. The method of making printing plates, consisting of previously forming a back, then applying thereto an impressionable layer, simultaneously impressing the surface thereof with the matrix, and while the latter operation is still in progress beginning to strip olf the matrix. A

9. The methodof making printing plates, consisting of previously forminga back, then applying thereto by heat animpressionable layer and simultaneously impressing the surface thereof with the matrix. p

l0. The method of making printing plates, consisting of previously forming aV back, then applying thereto :by heat an impressionable layer simultaneously impressing the surface `thereof with the matrix, and progressively cooling the impressed surface.

11. The method of making printing plates,

consisting of relatively moving a matrix and a layer of type material in an impressionable condition, in progressive forming proximity, with sufficient pressure toward each other to leave a permanent impression of the matrix in the metal while the latter is in a plastic condition, and simultaneously accompanying. the said` forming step by a progressive cooling operation.

12. The `method of making printing plates, consisting of moving a matrix forward, depositing` thereon progressively a layer of type material in an impressionable condition as the matrix moves, impressing the matrix into the type metal and cooling the deposited layer while the matrix is still moving.

13. `The method of making printing plates, consisting of moving airmatrix forward, de-A positing thereon progressively a layer of type material in an impressionable condition as the matrix moves, applying cooling means, and, while still moving, stripping olf the matrix.

14. The method of making printing plates, consisting of relatively moving a matrix and metal in an impressionable condition in such relation to each other as to impress the surface of the metal with the matrix, applying cooling means to the impressed metal after it is impressed, and while it is still moving, stripping the matrix from the cooled plate thus formed.

15.` The method of making printing plates, consisting of applying a matrix progressively over the surface of metal reduced to an impressionable condition by heat, immediately cooling said metal after its surface is impressed, and compressing said metal and matrix together while cooling.

16. The method of making printing plates,

` consisting of progressively forming a printing face on a back previously prepared including impressing said face with a matrix and simultaneously removing the matrix from the completed portion of the face without Waiting for the complete forming of the entire printing face of the plate.

17. The method of making printing plates, consisting of moving a previously prepared back between a cylinder and concave mold,

`and simultaneously feeding in with the moving back a matrix and a surface metal in an impressionable condition between the matrix and back in position to be compressed between the cylinder and mold.

18. The method of making printing plates, consisting of moving a previously prepared back between a cylinder and concave mold, and simultaneously feeding in with the moving back a matrix and a surface metal in an impressionable condition between the matrix and back in position to be compressed between the cylinder and mold, and applying means to said mold for hastening the cooling of the metal.

19. The method of making printing plates, consisting of moving a previously prepared back between a cylinder and concave mold. simultaneously feeding in with the moving back a matrixa surface metal in an impressionable condition between the matrix and back in position to be compressed between the cylinder and mold, applying means to said mold for hastening the cooling of the metal, maintaining constant forward movement, and when the forward portion of the plate is properly cooled7 progressively removing` the matrix therefrom.

20. The method of making printing plates, consisting of bringing together type metal in an impressionable condition and a matrix perpendicular to each other without relative transverse movement.

2l. The .method of making printing plates, consisting of bringing together a haelt, type surface metal in an impressionable comlition, and a matrix by a compressing movement perpendicular to the plane of said three parts at the impressing or forming region thereof.

The method of making printing plates. consisting of bringing together type metal in an impressionable condition and a matrix with a pressing movement perpemlienlar to each other sutlicient to impress the matrix into the metal without relative transverse movement, and immediately cooling the impressed metal.

In testimony whereof, Vl have signed my name to this specification. in the presence ol two snbseribing witnesses.

JOHN (Y). DE 'Ollli.

Yitnesses Grao. H. Maxwmm, TAL J. PIKE.

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