US2666002A - Contrasting colors for type matrices - Google Patents

Description

Jan. 12, 1954 w HEINECKE 2,666,002

CONTRASTING COLORS FOR TYPE MATRICES Filed Sept. 29, 1951 IN V EN TOR.

W/LL/AM HE/A/ECKE BY A TTORNE Y Patented Jan. 12, 1954 OGNTBASTING COLORS FOR TYPE MATRICES 9 Claims.

LThisJappIication is a continuation-in-part of my co-pending application, Serial No. 83,325,

filed March 25, '19i9now abandoned.

The invention relates to the provision of contrasting colors on matrices for integral line'type so that .an identifying character thereon may have a background which will renderthe character easily visible.

In the casting of integral-line type fromconventional type metal the usual procedure comprises the selection of brass matrices for each type from their respective magazines or chutes by .a manually operated key board. The se lected matrices are automatically placed in a clampingdevice to form a line and then-molten metal is forced into the dies of the matrices to cast a slug of the type.

During the above mentionedoperation the operator is never able tosee the die portion of the matrix and the only way by which he may determine whether he has selected the proper matrix is from a small identifying character corresponding to the type character of the die and which is stamped on the opposite edge of the matrix. These identifying characters are customarily considerably smaller than the corresponding die so that theirvisibility is not great.

Furthermore, in course of use, the matrix becomes covered with a dark grime of lead sulfide from the type metal as Well as of graphite which is employed as a lubricant for proper sliding of the matrix in the magazine chute and the automatic sorting means for returning the previously used matrix. This grime is'periodically removed by various agents such as described in my copending application, Serial Number 705,481, filed October 24, 1946, which issued October 28, 1952 as Patent 2,615,825.

Whether the matrix is clean or dark there is usually insufficient contrast in color of the identifying character to enable the operator to read the "line being formed by the matrices. Vari ous means and methods have been proposed to provide sufficient contrast such as the employment of dark backgrounds and whitened characters such as described in United States Patents Nos. 1,466,437 and 1,796,023. In these patents no suggestion is given as to how the back ground may be obtained except by some chemical action such as oxidation. So faras I am aware, the only chemicals that have been em--- ployed commercially for this purpose have been copper nitrate or copper carbonate, wet proo- 2 esses. These wet processes are carried out by boiling the solution in to produce a film which will last only about six months in ordinary use. Furthermore, in practice the solutions not only'attack or plate the desired edge portions but the liquid creeps even into the die thus impairing its accuracy. These processes are necessarily delicate, and are not carried out in the absence of special service shops. Consequently the process is of little use to the Linotype users except those comparatively few where such shops exist.

An object of the invention is to provide a dry method for darkening the matrices which can be carried out by any Linotype operator without danger to the dies and which will utilize only simple equipment salable as an article of commerce.

I have found that a highly satisfactory degree of color contrast between the identifying charactor and its background may be obtained by merely filling the indentations of the stamped identifyingcharacter with an inert white chalky pigment and darkening the background or matrix edge face by the formation of a sulfide coating thereon.

I have found that if the matrices to be treated after they are cleaned and dried are held in a clamp with their lateral faces together and their identifying characters more or less alined, the pigment may be applied simply by rubbing the characters with chalk, and the character faces may be darkened by the application of a sulfur emitting compound. The nature of the sulfur compound to be used is of the utmost importance as it must come in intimate contact with the surface to be darkened and yet must be such that no excess can be left on the matrix and must not emit any offensive odor. If the darkening compound is ap lied in liquid solution there is great danger that the liquid be drawn in between the matrices by capillary attraction so as to darken other portions of the matrices, and attack the dies. In my invention, 2, dry organic sulfur compound preferably on a carrier is heated to its melting and/or decomposition temperature adjacent the surface'to be darkened. While the exact nature of the decomposition products vary, their odor is not noticeable and their action can easily be localized to the surface desired. I

I have found that of a large number of sul fur compounds the more satisfactory ones are contact with the matricesthose which also contain amino or substituted amino groups, and of these, those which contain the group are especially desirable. other tautomeric compound which will form such a group will also be satisfactory.

I have found that the sulfur compound most satisfactory is thio-urea or, its equilibrium isomer, ammonium thiocyanate. Herein both of these compounds will be designated as thio-urea since the thiocyanate is largely converted to thio-urea at the temperature employed.

The compound such as thio-urea is preferably impregnated in a porous strip of absorbent material, then dried, and the strip laid on the matrices at the area to be darkened. The thiourea is then heated above its melting point and the sulfur emitted during its, at least partial, decomposition forms a film of sulfide of copper on the matrix. While the film is of slight thickness and hardly susceptible of analysis, it appears to be cuprous sulfide owing to its almost black C010r and the fact that it is formed in a reducing atmosphere.

In the accompanying drawing showing, by way of example, two of many possible embodiments of the invention,

Fig. l is a perspective showing a matrix,

Fig. 2 is a plan of a clamp holding the matrices therein, and

Figs. 3 and 4 are diagrammatic representations of means for heating the impregnated strip.

lhe brass matrix it is shown in Fig. l is provided at its rear face it with a die or mold (not visible in Fig. l) in which the types are cast.

The front or background face i2 is provided with an identifying character 13 corresponding to the die character. The character It is usually formed as an indentation merely stamped or punched in the brass without consideration as to the size except that it must be well within the margins of the face I2 and so it is much smaller than the type cast from the matrix. These characters afiord the only means for the operator to read what he is setting up. The matrix is provided with an car It and a toe [5 at opposite ends of the face l2.

In carrying out my invention a number of matrices are clamped in any suitable means such as a clamp it having sides i? and end piece is wherein the matrices are held tightly between the end piece [8 and follower iii, the pressure being supplied by a screw 20 received in a suitable mount 2|.

All the faces 12 are upwardly exposed and the characters it more or less alined. A colored pigment or ceramic color is rubbed into indentations of the characters and any excess is wiped off to leave the faces l2 clean. The pigment should be substantially inert toward sulfur and of course not greatly injure brass. Calcium sulfate, for instance, is satisfactory and may be used either in stick or powdered form. Of course the freer the indentations are from grime and dirt the better the pigment will be retained.

After the characters are whitened or colored,-

a strip, preferably dry, of fibrous or absorbent material 22 impregnated with an organic sulfur compound such as thio-urea, is laid over the faces l2 between the ears l5 and toes 46. The strip is then heated to decompose at least a portion of the thio-urea, as evidenced by the darkening of the faces, bymeans of an infra-red Obviously any '4 radiant heater 23 or other heating means such as a heated roll 24. The dark film on the face thus formed is not substantially affected by sulfuric or chromic acid, amines or any of the agents used for cleaning the matrices. The contrast between the colored pigment e. g. calcium sulfate and the black background affords excellent visibility of the character. The film so produced is resistant to the action of air and heat and no material change has taken place over a test period of several years on matrices so treated and cleaned.

As previously pointed out above many other compounds may be used instead of the thio-urea, such as rubeanic acid (dithiooxamide), diphenylthiocarbazone, thiosemicarbazide, thioglycolicbeta-aminonaphthalide, ditolylthiourea, and thiocarbanilide.

The strip or ribbon 22 is preferably flexible so as to afford close contact with the faces, and may be of paper or cloth. However these materials frequently char at the desirable temperatures (C. and above) and present problems of cleanliness. Asbestos paper may be used although stiffness frequently prevents good contact with the faces. Spun-glass clothis the most desirable of all materials as it is stable to heat, inert to thio-urea, possesses great flexibility and presents no problem of cleanliness during operation.

The compound may be impregnated in the fibers of the ribbon 22 in any suitable manner although it is preferable that a binder inert to the sulfur compound be employed to cause the latter to adhere to the ribbon when the latter is dry if glass is the material. Nitro-c'ellulose or collodion is suitable. For example a mixture of thio-urea, intro-cellulose and ethyl lactate with a little oil of juniper empyreumatic and-ricinus oil as plasticizer is satisfactory. This mixture may be thinned, if too viscous, with alcohol and/or nitrobenzene for impregnation by immersion. The properties are not critical. The material of the ribbon and/or the binder appear to absorb, temporarily at least, a portion of the decomposition products.

If for any reason the dark film of sulfide of copper must be removed it may be done by the use of nitric acid. Care must be exercised lest the nitric acid reach the die portion since this reagent readily attacks the brass.

The sulfide film is not attacked by amines used for cleaning the matrices such as described in my above mentioned application Serial No. 705,481. However film formed by the copper carbonate or copper nitrate process are quickly lost.

The thio-urea does not emit any appreciable odor as is true when solutions of soluble sulfides or hydrogen sulfide are used. The brass is quickly darkened by the decomposition products of the thio-urea however. One reason for this may be due to a formation of small amounts of ammonia which are absorbed on the brass and so render the surface active.

While I have described the darkening process part1cularly with respect to matrices the same general method may be employed for producing sulfide films on metals generally. The amino products are particularly effective for use on metals which form ammonia complexes, such as copper, zinc, nickel, cobalt, silver and the like.

While the melting points of the sulfur compounds may vary widely I prefer to employ those.

which are solid at room temperature andhave a melting point below 600 F.

As will be apparent to one skilled in the art, the ribbon 22 should preferably be substantially free from materials which would fix sulfur at the melting point of the sulfur compound since their presence would cause sulfur or the sulfur-bearing products of decomposition to be fixed in the ribbon and therefore such products would not be available to darken the matrix. Otherwise additional amounts of the impregnant must be added to allow for the formation of fixed sulfur, with no additional darkening of the matrix.

The presence in the ribbon of metals, or their reactive compounds, which occur in the brass of the matrix, such as copper, would obviously cause to be fixed in the ribbon at least a part of the sulfur-bearing products of decomposition and prevent efficient darkening of the matrices.

Likewise, when thio-urea, or similar compounds containing the H2NPJ group mentioned above, are used as impregnants, the ribbon should preferably be free from materials which form sulfur containing reaction products stable at temperatures above which the dzhio-urea or the similar compounds are decomposed. It is obvious that the formation of such reaction products would require higher heating temperatures than would be necessary if there were no chance for the reaction products to form.

Whatever the nature of the ribbon fibers, it is of course preferable that they be inert with respect to impregnated sulfur compound and its decomposition products. Likewise it is preferable that the ribbon fibers be unafiected by, or inert to, heat at a temperature below the maximum melting and/or decomposition temperature for the sulfur compound set forth above, namely 600 F. Furthermore the ribbon is preferably substantially porous to permit diffusion of the fluid decomposition products so as to favor a uniform degree of coloration over the matrix face.

The invention claimed is:

1. A method for improving the visibility of characters punched in brass comprising filling the indentations of the characters with a substantially inert white pigment and melting thiourea adjacent the surface in which the characters are punched.

2. In combination, a ribbon of Woven spun glass, thio-urea within the interstices of the ribbon and a binder for anchoring the thio-urea to the fibers of the ribbon.

3. A combination as in claim 2 said binder being nitro-cellulose.

4. A method for improving the contrast between a brass type matrix identifying character and the surface of the matrix in which the character is stamped comprising filling the indentations of the character with a chemically and thermally inert light colored pigment; applying to the surface in which the character is stamped a strip impregnated with thio-urea, and applying sufficient heat to the strip to decompose at least a part of the thio-urea.

5. A method for darkening the background surfaces of brass type matrix characters comprising arranging a plurality of matrices so that the background surfaces all lie in substantially a common plane, then clamping the matrices tightly together, disposing a dry ribbon impregnated with an organic compound containing the group on said surfaces, and then applying sufficient heat to the ribbon to decompose at least a part of the compound, whereby a dark coloration is obtained on said surfaces.

6. An article for use in darkening selected brass matrix surfaces comprising a ribbon of woven glass fibers impregnated with thio-urea, nitrocellulose as a binder to anchor the thio-urea to the fiber and ricinus oil as plasticizer for the nitrocellulose.

'7. A method for darkening the surfaces of brass type matrices comprising arranging a plurality of matrices so that the surfaces all lie in a common plane, then clamping the matrices tightly together; disposing a dry ribbon of chemically and thermally inert material impregnated with a normally dry stable solid organic sulfur compound having a melting point below 600 F. on said surfaces, and then applying sufiicient heat to the ribbon to decompose at least a portion of the compound.

8. A method as in claim 7 said compound also having an amino group.

9. A method as in claim 8 said amino group being a primary amino group.

WILLIAM HEINECKE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,844,199 Bicknell et al. Feb. 9, 1932 1,867,658 Dreyfus July 17, 1932 2,297,909 Neely et al. Oct. 6, 1942 2,311,613 Slayter Feb. 16, 1943

Claims (2)

1. 5. A METHOD FOR DARKENING THE BACKGROUND SURFACES OF BRASS TYPE MATRIX CHARACTERS COMPRISING ARRANGING A PLURALITY OF MATRICES SO THAT THE BACKGROUND SURFACES ALL LIE IN SUBSTANTIALLY A COMMON PLANE, THEN CLAMPING THE MATRICES TIGHTLY TOGETHER, DISPOSING A DRY RIBBON IMPREGNATED WITH AN ORGANIC COMPOUND CONTAINING THE
2. 6. AN ARTICLE FOR USE IN DARKENING SELECTED BRASS MATRIX SURFACES COMPRISING A RIBBON OF WOVEN GLASS FIBERS IMPREGNATED WITH THIO-UREA, NITROCELLULOSE AS A BINDER TO ANCHOR THE THIO-UREA TO THE FIBER AND RICINUS OIL AS PLASTICIZER FOR THE NITROCELLULOSE.

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