US2103764A - Method of making level faced matrices - Google Patents

Description

Dec. 28, 1937.

c. E. BOUTWELL Filed Feb. 15, 1936 IEIFQIEEIIEHEIFIIEIII'IEIII in; QEIEIIQILEIE gum EllgllgllgjlllLglLgllJHElEl I ll !lEIIQIEIIQIIQIEIEIIEIEI /7 [25 Z /IB WWW {/727 INVENTOR umrence. E. BouTwe ATTORNEYS:

Patented Dec. 28, 1937 UNITED STATES PATENT OFFICE METHOD OF MAKING LEVEL FACED MATRICES This invention relates to a method for making matrices for printing plates, and has for its object the provision of a method of the character designated which shall be effective to produce in ,5 a minimum of operations a matrix in which all of the details of a design or setup may be reproduced without further levelling upof the printing surface. V

A further object of my invention is to provide a leveling device for wax models employed in making my improved matrices, which shall be effective to insure that all surfaces in relief on the model shall be brought into proper relation with each other, e

l8 My invention particularly contemplates the developrnent of a hard surfaced matrix, such as of plaster of Paris, or what is known as synthetic stone, such as is employed for reproducing finer ;gg produce fine work, such as fine screen photo etchings,and line work, particularly where there are a plurality of fine lines or 'points, that the lines or points in relief on the printing surface must be perfectly even with respect to each other in 39 .order that all parts of the plate bear with equal pressure upon the paper when the printing is being done. Also, as is well known in this art, the more nearly perfect leveling is accomplished on a printing plate, the less make ready is re- 35 quired in preparing the setup for printing.

My invention also contemplates a method whereby hand work, such as art designs, and line work, may be employed in the designing of the 7 plate, and all of the lines and figuresthereby x40 produced be brought into proper prominence ion the plate for printing. h In the art of printing, as now known to me, printing plates, such. as electrotypes or molded plates, are first made with a suitable matrix to bring the lines or prominent printing surfaces into relief, and after being made are levelled up by polishing off the higher parts of the printing surface on a level stone, and also by backing the printing shell with lead and punching the backing with suitable tools to bring the lower surfaces intotheir proper position of relief. My invention particularly contemplates the avoiding of this work which requires considerable time and highly skilled labor, and the production of, a matrix carrying all of the fine details to be reproduced in proper relief position.

Briefly, my invention contemplates the making of an intaglio impression in a preliminary matrix capable of receiving and retaining an 5 impression of the minute details of the design to be printed, the making of a wax model from the intaglio impression, the leveling of the wax model by a mounting upon a suitable grid and the application of pressure, and the casting of a suit- .10

able hard matrix therefrom.

In the accompanying drawing forming a part of this application,

Figs. 1 and 2 are viewsshowing the steps of forming a preliminary matrix in my improved method;

Fig. 3 is a view. showing the step of forming a Wax model from the preliminary matrix;

Fig. 4 is a view showing the device employed and the method of leveling up of the wax model;

Fig. 5 is a plan View of the device employed in leveling up the wax model; and

Fig. 6 is a view showing the step of forming a plaster of Paris or synthetic stone matrix from the wax model.

Referring to the drawing, I first take a sheet of a material capable of receivingand retaining an impression, such as a fiong of paper or heavy sheet of blotting paper I0, and apply thereover a coating of cement made by dissolving rubber in benzol, or any other cement having the property' of separably holding the sheets together. Over the fiong or sheet ID as thus prepared, I place a sheet of relatively heavy metal foil II. The metal foil used for this purpose is in the neighborhood of 0.004 inch in thickness. The fiong or sheet In and the heavy foil sheet I I serve as a foundation over which is applied another coating oi' cement, and over this is placed a sheet of relatively thin foil [2, the upper sheet of foil be- 40 ing of the order of 0.0015 inch in thickness. I

The purpose of the cement over the sheet l0 and over the sheet of foil l l is to provide a yieldable substance beneath the sheets of foil to prevent its being cut ortorn by the finer or, sharper points or lines to be reproduced, .and'to hold the 'may. be made by a printing setup, or manually by a stylus. Fig. 2 of the drawing shows the I assemblyplaced on the lower platen I 3 of a suitable press with a printing form I4 ready to be pressed down into the sheets of foil II and I2 by the upper platen E6 of the press.

The impression thus made in the foil I2 is now ready for the preparation of a wax model. This step is shown in Fig. 3, in which the sheet In and the sheets of foil II and I2 are shown resting on a fiat surface I5 and surrounded by a suitable frame I1, and in this is poured melted wax I8, the wax being of a consistency comparable to that of mixed beeswax and paraffin.

As soon as the wax is cooled and hardened,

The purpose of retaining the thin sheet of foil 7 I2 on the wax model at this stage in the process is to prevent sticking of the wax in the steps of the process to follow. The foil employed may be any of the commercial soft metal foils, such as lead foil, solder foil, tin foil, and copper foil.

The foil covered wax model I8 is next placed, as shown in Fig. 4, upon a grid shown in section in Fig. 4 and in plan in Fig. 5, the grid comprising preferably a multiplicity of evenly spaced sharp prominencies or knife edges I9. The purpose of this grid is to provide a support for the wax model such that, upon applying pressure to the model it may be forced downwardly with the knife edges sinking into the wax. At the four corners of the grid I8 are stops 29, the upper surfaces of which are even with respect to each other. A smooth rigid plate of glass of other suitable material is then placed over the foil covered wax model, as shown in Fig. 4, and is pressed down evenly with the hands, or otherwise, toward the grid until the sheet of glass comes in contact with the stops 2!). The operator can observe through the glass when all lines or figures in the design on the model are in contact with the under surface of the glass. When this is accomplished, the wax model is perfectly leveled and is ready for the formation of the hard matrix.

It will be seen that in pressing downwardly upon the wax model with the sheet of glass 25, the pressure will be concentrated on the more prominent surfaces, causing the model opposite such surfaces to sink more deeply into the grid I9. The stops 29 should be removable and sets of different lengths provided to accommodate models of different thicknesses.

If a matrix having absolute fidelity of detail is desired, the relatively thin sheet of foil I2 is next stripped off the wax model; otherwise and ordinarily, it is left in place. A suitable frame 2I is next placed around the grid I9 and the wax model I8, as shown in Fig. 6, and a suitable cement, such as plaster of Paris, synthetic stone, or other fine cement 25, is poured into the frame over the wax model. When this cement has set, the hard matrix is formed with an intaglio impression of the original design, ready for the casting or production of printing plates in' any manner that may be desired, therefrom.

From the foregoing description it will be apparent that my improved process is particularly adapted to the formation of printing plates where manual design is involved. In the drawing of designs directly upon the preliminary matrix shown in Figs. land 2, it is practically impossible to have the lines of equal depth in the foil receiving the impression, throughout their length, or to have different lines of equal depth in the foil. Where a design is thus applied to the foil in accordance with my process, and a wax model made, the lines are all brought to an equal height on the model by the procedure shown in Fig. 4 of the drawing, that is, by placing the model upon the sharp points of the grid and pressing downwardly on the model with the smooth sheet of'glass. The method is also obviously of value in leveling up the surfaces produced by a printing setup, wherein, as is well known, it is extremely difficult to have the various printing surfaces of equal prominence in the setup.

While the finer details of reproduction are accomplished by means of the preliminary matrix illustrated in Figs. 1 and 2, where reproductions of printing setups alone are to be made, the preliminary matrix may be made in any suitable manner other than that described herein, and a wax model made therefrom, as described in connection with Fig. 3 of the drawing, and leveled up as described in connection with Fig. 4 of the drawing.

The thin foil I2 employed by me for making the preliminary matrix is so sensitive to impressions that accurate reproductions of fine screened photo etchings can be reproduced with greater fidelity than is possible with an electroplating I ing or drawing of designs upon the thin foil,

where it is necessary to employ a very sharp pointed stylus, I recommend the placing of a thin sheet of transparent material, such as a sheet of regenerated cellulose, between the stylus and the thin foil.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. The method of producing matrices for printing plates which comprises first forming a preliminary matrix by superposing a relatively thin metal foil sheet over a foundation of yieldable material capable of receiving and retaining an impression,

forming an impression in the preliminary matrix ing plates which comprises first forming a preliminary matrix by superposing a relatively thin metal foil sheet over a foundation of yieldable material capable of receiving and retaining an impression, forming an impression in the preliminary matrix by impressing a design into the metal I foil, forming a wax cameo model from the preliminary matrix, stripping the foundation from the wax model leaving thereon a sheet of metal foil, mounting the wax model thus formed upon a grid comprising a multiplicity of sharp prominencies, leveling the cameo surfaces of the model by pressing downwardly thereon with a smooth level surfaced member, and casting a hard intaglio matrix from the Wax model.

3. The method of making matrices for printing plates which comprises forming an intaglio impression to be reproduced in relatively thin metal foil, forming a cameo wax model from the metal foil impression, mounting the wax model on a grid comprising a multicipility of sharp points, leveling the model by pressing downwardly on the metal foil with a smooth level surfaced instrument,

and casting a hard matrix from the model thus 5 leveled.

* CLARENCE E. BOU'IWELL.

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