US9790A - John l - Google Patents

Description

UNITED STATES PATENT OFFICE.

JOI-IN L. KINGSLEY, OF NE\V YORK, N. Y.

MOLDING- GUTTA-PERCI-IA STEREOTYPE-PLATES.

T0 @ZZ 107mm t may concern Be it known that I, JOHN L. KINGSLEY, of the city of New York, in the county and State of New York, have invented a new and Improved Mode or Process of Molding Plastic Substances; and I do hereby declare that the following is a full and eXact description thereof, reference being had to the annexed drawing, making a part of this description, and to marks of reference thereon.

Figure l, of the drawings, is a longitudinal section of a press showing the molding frames and other connect-ions, as used in my process. Fig. 2, is the molding frame in perspective. Fig. 3, is a perspective view of a form when molded, or which may be molded from. Fig. 4L is a perspective view of the thin protection plate, to surround the form which is in the process of being molded Fig. 5, is a perspective view of the refrigerator case, and its drawer as described.

The nature of my invention consists in providing a ready and effective method or process for the purpose of molding plastic compositions, made from compounds of gum (as gutta percha or india rubber) with metallic or earthy substances; or any other materials of such like character. The main object being to mold plastic substances in a true form to represent the reverse of the mold in which they have been cast, by eX pelling all the air from the mold while the mold is being filled, so as to render the cast in all respects perfect. And a further object being so to work these articles as to render them useful in the arts for the purpose of making molds and plates for stereotyping, (or stereography); the same to be used as substitutes for the other known methods of producing such articles as applied to the art'of printing.

Although I consider a verbal description of my process entirely clear, the imperative character of the law seems to require the further aid of model and drawings.

Fig. l may be considered as a longitudinal section, through the center, of a common copperplate press, having the addition of bearers at each side, and laid upon the bed are the several parts for use, now to be described. The frame (a) is shown in the back ground, as is also the bearer (b) on the side of the bed. The windlass or arm (c) being shown still beyond and on the outside of the frame. The regulating or pressure screw is at the top of the frame and known as Connecting rods (e, e, e, e) join the two sides of the frame into one general frame. The bed (f) is a planed plate of iron, upon both its upper and lower sides, and at either of its two sides has the bearers (o) arranged, the height of these bearers being precisely equal to the height of the molding frame (g) The molding frame (g) will be better understood by referring to Fig. 2, where it is shown disconnected from all other parts of the machinery. In this figure (c) is the inner edge, or that part which is parallel with the sides of t-he type as shown. (a is the top or bearing surface. (am) is the connecting part from top to bottom, and drops over the chase and furniture, as shown in the drawings Figs. l and 2.

The form or chase, furniture and type, as prepared for use, is shown at Fig. 3, and .(J) in Fig. l, and is in all respects of the common construction.

Fig. 4 is a plain frame of thin cast steel known as (s) in drawing, the inside of which is to fit snugly around the form and to be of sutlicient width to extend over the furniture so as to keep the composition from adhering to the wood, or furniture.

The refrigerator case and drawer are shown at Fig. 5; the case is a metal boX open at one end to admit the insertion of the drawer (Z) of common construction. This part of the machinery is to be used in the last or hardening part of the process, hereinafter more fully described.

Thus the machinery being described intelligibly as to its construction, except in so much as in all respects common and in every day use, I leave this branch of the subject.

Of the procesa-I provide a composition and reduce the same to a soft or plastic state, if not already in such state. These compositions may consist of any material as clays or earths, to be softened by wetting; as horn, shell, glue, or glutinous substances; as gums, or any similar substances to be reduced by heat, but a special reference is had to the gums, as (gut-ta perchal or caoutchouc), and particularly to compositions or compounds made in part of one or both these gums and other substances.

I will here remark that I am about toap ply for a patent for a compound of this sort to be applied to use by means of the following manipulation. I suppose the composition to be in a soft or plastic state, having reduced it to that state by allowing it to remain in hot wat-er until it has become soft. The soft material is then passed through steam heated rollers; (these are of any co'mmon construction) this masticates or equaliZes the lump or body of material, and reduces it to a sheet of any desired thickness to Vfill the mold about to be used. I then receive the sheet upon a wet cloth (to prevent adhesion,) and lay it, the sheet of prepared gum, upon a steam heated table; (this is also of common construction and familiar to all who use the gums referred to) 5 here, I cut by a pattern, from the sheet, a piece of the desired size; this I place upon a sheet of polished steel, (having previously rubbed the surface to receive the gum with a fine powder of plumbago or black lead, this is to prevent adhesion to the steel, and may be considered as a lubrication, as liquids may not be used for this purpose, with the gums, without more or less deterioration). I-Iaving previously prepared the mold, or the form for the mold, (if in stereotyping), by rubbing all the parts which are likely to come in Contact with the gum, with the black lead powder, I slide the sheet or piece of gum, before prepared, to its place in the mold or on the form,-as the case may be. l

I will here remark, that, although the common presses may be sometimes successfully used for the purpose of molding the gums, or such like compositions, into molds of limited dimensions, yet failure has frequently ensued from an impossibility to eX- pel the air from the mold. The common way to use, being to lay the mass upon or into the mold, and to prevent it hardening too soon, give a rapid pressure; this', of course, only compresses the material and the more closely confines the air, which to give a perfect mold, or representation from a mold, should have been expelled. F or the purpose of fully expellingthe air, I have used and do use, a cylinder or copper plate printing press; thus the form or mold may lie upon the bed, (as shown in the drawings and otherwise herein referred to,) and the cylinder be allowed to pass over the mass, thus one part is reached first and by degrees the advancing bed of the press brings the whole surface beneath the roller or cylinder for pressure; thus the bed may be moved backward and forward as often as necessary, always driving the surplus mass, if any, before it, and if any air remained it is likely to be expelled by the second or third rolling, particularly if the pressure be increased at such repeated rollings. (It will be understood that so far as the foregoing is concerned the cylinder has given but a pressure upon a single line across the mold when passing over it). But, to return to the matter of process; we will suppose the form to be placed as shown in the drawing, before referred to; the press about to advance as referred to. I then, as the press approaches the form, drop the first end of the sheet into the molding frame, and upon the form; this end is then caught by the cylinder, and as the cylinder advances in its rotary motion the bed and form advance in a horizontal or lineal motion, each equal to the other, and thus the sheet of prepared gum is taken in, it being gradually slid from the steel plate upon which it had been laid for that purpose, until the whole is upon the mold, and has been pressed by the cylinder. The real object of using the steel plate is to keep the sheet from the mold, except at the line of impinging of the cylinder, until it is fairly pressed down into the mold by such impinging in order that all the air may be driven out before the gum drops into its place, as the pressure is advancing toward v it, this continuing until the whole is pressed into the mold, when several additional rollings may be given by passing the mold to and fro under the cylinder. The mold having thus been fully formed must be reduced to a level on its back, (and of equal thickness, for a stereotype moldg) for this purpose I use a thin sharp knife, or a plane, and with it I cut off all surplus material to a level with the top of the molding frame. (This must be done before the material becomes fully hard or what is equivalent to it the knife may be heated.) By removing the molding frame the mold will be found complete. You will then raise the thin frame (s) and with it the mold which will be thus gradually and evenly drawn from the form of type; the mold is now complete and free from the type, and if any parts shall have been pressed through at the edges they should now be trimmed off with a common knife or shears.

We now come to the hardening. The mold just described as complete, should be perfectly hard before hot gum can be safely introduced to it, a few minutes will effect this, if left in the open atmosphere in a cool place; but I prefer to use a refrigerator. A common refrigerator will answer all the purposes, if used in connection with a case and drawer, as shown in the drawing. I prefer to have the case with its drawer lying upon the ice in the refrigerator all the time, except when taking out or putting in plates. This will always keep the parts very cool, and a plate laid in the drawer, the drawer put in its case, and the whole laid upon the ice for three or five minutes will make it sufficiently hard to receive the hot gum for the purpose of making a plate, which plate will be a positive representative of the type from which the mold was made, requiring no dressing or otherwise arranging to print from it, than simply trimming the edges. By the time it is hard enough to separate from the mold and the edges trimmed it may be put to press and is ready, and hard enough to print from.

The before described process of molding is repeated in making the plates, there being no difference between molding in one of these metallic gum molds and a metallic or composition or even a wooden mold provided the black-lead powder be freely used. lt is imperatively necessary that this lead powder should be freely used by rubbing on a thick coating, and when all is thoroughly coated the loose particles should be blown off. The person handling should carefully coat his hands with this material, and the steam rollers, in short everything the composition meets should have a coating of it, for

it will not adhere to whatever has this material upon it. One of the greatest difficulties in working the gutta percha, has always been its strong tendency to adhere to everything it comes in contact with, therefore consider this as a great feature in my discovery, as it will prevent its adhesion to even hot metal, or to hot pieces of itself will require considerable working to cause one to adhere to the other when both have been well coated with it.

Remarks-The system of stereotyping` at present in general use is simple in itself, but requires much time, care and experience; in short is carried on as a special trade. The process is as follows, viz:

The type being composed. and locked up, substantially as it would be to go to press, has a frame laid over it to keep the plaster from running out. The whole is well oiled to prevent adhesion, plaster of Paris is then dissolved to a thin paste (say of the consistency of cream,) this is poured into the frame, a little roller made very soft, is then used to roll the creamy substance, by rolling, until it has penetrated every part of the face of the mold, or rather the type; while this is going on the plaster or cement is hardening. The operator being satisfied the mold is full at the face, fills in more material until the frame is heaping full, when it is hard it is trimmed off, and taken off the form and out of the frame. This mold is then baked in an oven, after which it is placed in a fiask prepared for -the purpose and the flask and mold are together dropped into a kettle of melted type metal, where it remains until the mold or flask is thoroughly filled, when it may be withdrawn to cool. After cooling the fiask is opened, the mold and plate are then firm in one body, when the plaster is broken to pieces, and much labor is required to remove it from the form; a stiff brush with water is used to remove the grossest part but much time in picking, with small picks, is necessary to remove all of them; if there are any bad'letters or parts of a page they are replaced with a new type or a new piece, the bad piece being cut out for the purpose. The first part is termed casting, and the second part finishing; and generally different sets of hands are employed for these two departments. The molding and casting can be done in about four or five hours, but is usually done on different days. The finishing occupies time in proportion to its defects, more or less, but generally far more time is used in finishing than in molding.

Many experiments have been tried to bring about a more speedy and economical way of stereotyping. In France, it was supposed that molds pressed in papier mch would prove successful and that metal plates could be cast in them which would not require picking, and therefore become economical as to time. In England the same experiments were tried. In this country the same; but the result has uniformly proved unsuccessful, the main difficulty being to expel air from the molds in materials of so stubborn a character. Thus this may be considered as a fruitless experiment so far as has been practised to the knowledge of the world. At all events it has been abandoned. Another French invention, has been to use preparation of bitumen, but the confined air has been its death, as in the case above cited. I will also add that many eX- periments have been tried in Europe with gutta percha, (the plain gum,) but with similar ill success. Many very pretty letters and some small sized plates were shown at the late c"Worlds Fair, but these were chosen specimens; practice has shown their impracticability so far as the art has been carried. For we find the air confined below a tenacious surface will remain there to deface and render imperfect the very face which it is desired to leave perfect. Besides the before named defects, the pure gutta percha is too easily soluble in a moderate 'L heat, when not chemically combined with harder substances, to use in printing. Tn short, is not hard enough when not in the least heated, except when old.

Comparison-For the purpose of evincing the economy of my process, as herein described, in comparison with t-he others referred to, i will state that my whole operation of molding, (including preparing the gum), does not occupy more than five minutes, and three minutes more will render the gum perfectly hard for use, when used for stereotyping. Three minutes more will suffice to make a plate, and three minutes more to trim and put it to press, so that in all cases fifteen minutes will suffice to put a hurried form to press after the types are prepared, as they would be for the press, in the ordinary manner. I will further state that the compositiony for which l contemesv late a al in for a atent as before referred taci) yis apable ldf being( thus worked without any of the objections made to the simple gum. As compared with bitumen, with the papier mch, etc., the economy is great, the lirst being for plates, to be taken in the papier molds, and the other being for molds in which either bitumen or metal plates may be made, leaves each in the position of half the grand result, and in no case could the required operations in them be performed in less than double the time of my process.

I believe it will be consistent to repeat that from four to siX hours are required in the common process. Thus there seems to have been an insurpassable barrier to the adoption of either of the known methods in the walks of the newspaper world. Another objection to these other methods is that no page above a given size can be successfully molded or cast by these methods.

Now I shall claim to have accomplished the following advantages,-1st, I can mold by this process as large a page as may be required, because I expel the air before the cylinder, and as the sheet is being dropped to the form; and this part could be as Well applied in the other cases as when used with my own composition. 2nd in making compositions which will serve for both molds and plates, capable of being re-used by simply re-heating, and passing through the rollers; that is, that the material is not deteriorated by repeated use or by time, I am enabled to apply my process to great advantage, and at comparatively no cost.

I save the wasted plaster mold or the wasted papier' mold. I save the whole process and time of finishing as the mold I make does not shrink or swell by heat or cold; thus I produce a perfect fac simile of the type from which the mold was made. Again the advantage of using stereotype plates, now offered, by this process, to the public, which are sutIicient for newspaper Work in all respects, I accomplish the great object of taking but one impression, (a mold), for each form; but I print from plates made in these molds, which are convertible, in full quantity, into plates again; thus the types instead of being used as now for making many thousands of impressions per day or week, will be left to be used as many days for each particular single day, as there are copies printed upon them in that day; in other words the types will wear comparatively longer as the number of impressions are decreased. It being a well known fact that newspapers and large book printing establishments print many thousands of impressions daily upon the types, while by this plan only the mold is required as before stated. As an instance, if a paper now prints twenty thousand copies in a day from the types, it will take twenty thousand days to wear the types as much as one days use now wear them by this process of taking one mold impression only per day.

Having thus fully described, compared and explained my invention by reference to the known methods of accomplishing such work, what I claim as my own invention and desire to secure by Letters Patent of the United States, is as follows, viz:

l. I claim the process of expelling air from the surface of the type when forming the mold and from the surface of the mold when forming the plate, substantially in the manner set forth or in any equivalent way.

9.. I claim the method described or its equivalent of dressing, leveling or thicknessing the molds and plates, when made of gutta percha or compound, so that all the plates made shall be invariably of the same thickness, all of which is herein fully described and set forth.

Gro. R. lVEsT.

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