US1452872A - Method of producing phonograph records - Google Patents

Description

Apr. 24, 1923.

v. H EMERSON METHOD OF PRODUCING PHONOGRAPH RECORDS Filed April 20 mvem/to c Wcior/[E 771 mm: @t 1Z3 61mm Patented Apr. 24, 1923.

UNITED STATES PATENT UEFECE.

VICTOR H. EMERSON, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO METAL RECORDING DISC COMPANY, INC., A CORPORATION OF NEW YORK.

METHOD OF PRODUCING PHONOGRAPH RECORDS.

Application filed April 20, 1920. Serial No. 375,242.

To all whom/it may concern:

Be it known that I, VICTOR H. EMERSON, a citizen of the United States, residing at the city, county, and State of New York, have invented new and useful Improvements in Methods of Producing Phonograph Records, of which the following is a specification.

My invention relates to methods for mak ing phonograph records, or, more particularly described, to the formation of a record surface upon layers of materials which, while not possessing all the peculiar properties required for phonographic reproduction, contain other important features adaptable to strengthening and otherwise improving the record as a whole.

In my co-pending application Serial No.

37 5 ,243 filed of even date herewith and which has matured into Patent No. 1,416,342 granted May 16, 1922, I have described a disk record having as a component element a thin plate of metal with a layer of record material upon the surface of the metal; and I have therein also disclosed in more or less general terms the method whereby the type of sound record referred to is built up including a flat, cushioning layer as a component element thereof for the purposes described in said application. a

In the present method, however, I employ.

a process that differs in an important detail from the one there disclosed, wherein by supplying a thermo-plastic layer between the steel disks the cushioning feature, being only required during the pressing process, is eliminated as a permanent element of the record itself.

Therefore as a preliminary step I first predisk is used, as will presently be described more in detail. The metal surfaces may be variously treated to render them suitably receptive for permanent coatings of the kind referred to, but I find from experimentation that either of two methods may be successfully employed. A coat of japan or any suitable lacquer may be applied by brush or other convenient means as a relatively permanent adhesive coat upon the surface of many metals and alloys, particularly on all grades of steel, with or without baking the coating thereon, the employment or omission of the latter step depending upon the type of paint used,with a view to making the union more permanent. bemade sufliciently irregular and pitted to receive the thermo-plastic materials as applied directly thereto.

Upon the disk of metal thus prepared I place a mass or ball of thermoplastic record material in a central position, and then place the disk thus provided upon a like quantity of the record material which in turn rests upon the under matrix plate of a phonograph stamping press and immediately apply the usual pressing or stamping action, bringing into contact with the mass of record material the top plate of the press similarly prgvided with matrix for pressing sound recor s.

As theoppositely disposed matrix plates approach each other, the several masses of thermoplastic material simultaneously spread equally in all directions toward the periphery of the disk, thereby covering each of the surfaces of the metal disk with a veneer of record material into the respectiye faces whereof sound records have been impressed.

The quantity of record material thus applied to the top and bottom of the disk of metal is first predetermined so as to provide a uniform covering of the required thickness from center to circumference upon both faces of the disk, and if desired enough may be added to extend the flow a slight distance beyond the edges forming a smooth edge or rim with a continuous unbroken surface, which may bepressed or ground down to any desired diameter.

Or, these surfaces may It is to be noted that in thus applying the record material in the manner described the central mass during the pressing operation of itself supplies the required elasticity to the action of the rigid pressing plates as they are fully brought together, for as the respective masses of thermo-plastic material are pushed outwardly under the pressure and heat required in the process, they both flow equally and simultaneously in all directions, and in this manner the one mass is played against the other, the respective circumferences as they grow outwardly above and below the metal occupy substantially the same opposite positions at all points throughout the pressing disk operation.

The application of my process has thus far been described with reference to a single metal disk for each record with a layer of record material upon its two faces. It will be apparent, however, that two such metal disks may be employed, in which event it will obviously have a surface coat of record material upon one face only of eaclnof the disks.

In uniting the disks in the manner described I find it preferable to secure the parts together by means of a ball or mass of thermoplastic material applied centrally in the manner above described in connection with the record material, and in employing substantially the same quantity of thermoplastic material between the disks as of record material at their outer surfaces, the

. three masses will spread simultaneously and co-extensively, and in this manner the relatively rigid and unyielding metal layers will offer no serious or unwieldy resistance to the action of the matrix plates, and thus there is avoided the danger of irreparable injury which would otherwise be caused to those delicate prepared surfaces.

Having reference to the drawings illustrative of apparatus preferably employed in the practice of my improved method, and certain of the products thereof Figure l is an edge view of disks and masses of material in position to be pressed thereon.

Fig. 2 is a view similar to Fig. 1 with the press as it would appear in process of action.

Fig. 8 is a view similar to Figs. 1 and 2 after the press has completely operated, the layers of material therein shown greatly exaggerated in diametral section largely exaggerated; and

Fig. 4- is an edge view of the finished records.

Referring to the drawlngs, the numerals 1 and 2 are disks f similar form made from thin metal stamped from sheet steel preferably having a mass 3 of record material centrally resting above the disk 1 and an other mass 3 similarlyplaced theidisk 2, the,

last mentioned'mass resting upon the lower matrix 4 of the bed plate of a press such as is used for stamping out phonograph records.

A third mass of thermo-plastic material is also centrally disposed between the two quired degree of heat applied to the several masses'of thermo-plastic material in the usual way the pressure is applied with the result as shown in Fig. 2, where the press is represented in the process of spreading the masses, and then in Fig. 3 where the thermo-plastic material is shown completely.

spread over the surfaces of themetal d sks and uniting beyond the edges, it being seen that the record material in all of the views is shown largely exaggerated in thickness merely for the purpose of showing more clearly the interrelation of the parts.

Fig. 4 represents the finished record produced by my process, but with the respective layers also here shown somewhat exaggerated, in thickness, but otherwise illustrated in substantially their true relationship one to the other.

The method of applying the record material as a mass to be spread over the surface by causing the material to flow outwardly has a double advantage, first, in that it produces structurally a superior record surfacethan when first spread over the surfaces of the disk and then impressed fiat with the matrix plates and, secondly, that it maybe applied directly to hard, non-yielding materials, such as the metal disks of the present process, without injury to the matrix plates. In my present process I do not consider this method f applying the record material in itself broadly new except as used inconnection with metal disks, and

it is believed the method in that particular form is new and highly important, and is desired to be protected by Letters Patent.

Having described my invention, what I claim is:

l. A method of forming sound records which comprises the following steps: preparing a thinmetal disk, toughening the surfaces of the disk and applying a mass of thermo-plastic record material to each of said surfaces at substantially the centers thereof, applying heat to render said masses plastic and then pressing the sound record groovesinto saidrecord material by means of matrices as said matrices spread said record material upon the surface of the disk. i

2. A method for forming sound records upon ametall disk, tymeansef corroding-the" surfaces of the metal and applying centrally thereto a mass of thermo-plastic ma terial to each face and pressing the same between sound record matrices.

3. A method for forming sound records which consists of preparing disks of metal,

separating the disks by means of a mass of thermo-plastic material, applying a mass of thermo-plastic record material to each of the outer faces of the disks, applied cen- 10 trally in substantial alignment each with the other, and pressing the masses flat upon and between said disks by means of matrices having sound records in the surfaces thereof.

In testimony whereof I have hereunto set my hand.

VICTOR H. EMERSON.

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