US1101827A - Process of making duplicate phonograph-records. - Google Patents

Description

STATES PATENT JoNAslw'. AYLsWoRTH, or EAST ORANGE, New JERsEY, yassiettes'. fro new anlasser PATENT COMPANYpOF WEST 0R llGyrlEl,y NEW JERSEY, A CORPORATION F NEVJ Jnnsnr.

Specication of Letters Isatent.

Patented?. furie E Application Hed September 4, 1909. Serial No. 516,309.

Td all ywhom t may concern, Beit known that I, JoNAs WV. Arns- WORTH, a citizen of the United States, and

a resident of East Orange, in the county of Essex and State of New Jersey, have invented a certain new and 'useful Process of Making Duplicate Phonograph-Records, cf which the following-is a description.

My invention relates to a process for making phonograph records in` which thevvearing surface is'entirely of metal. This material may constitute the entire record4 or may be a shell pro-vided with a backing of other material.

The process is particularly adapted to the manufacture of cylindrical phonograph records, although it may be used for making records of thedisk type, if desired.

Cylindrical sound records at thepresent time are generally made of a WaXlike material molded or cast Within a hollow matrix, and disk records are formed of some- `What harder material, employing considerable quantities of shellac, the impression being secured from a fiat matrix. With both types of record the material is subjected to considerable wear when used in a phonograph' or talking machine, and such wear y an indenite. number of co ies..

fr instance,

becomes objectionably great when the width of the record groove is decreased beyond a certain point or when' the pressure of the stylus upon the record is increased beyond a certain point. It has also been proposed to use for cylindrical records a material harder than the Wailike material just referred to,

Celluloid. Such records, however, are generally found to be of poorer quality as regards sound reproduction than those of Waxlikematerial, and they appear to deteriorate with time. Moreover, a eelluloid record is also subjected to objectionable Wear When the Width of the record groove is diminished or the pressure of the stylus increased beyond a certain limit. It has also been proposed to make duplicate phonograph records in metal, but such processes have been objectionable in that it has been necessary to destroy the to liberate the metallic duplicate.

By the present invention it is possible to 'readily free. the metallic duplicate from the matrix Without injury to the latter whereby the same may be used for the production of "be used 4suitable solution; for

' tate in a mixture of acetone and matrix morder y This material should be such as In order that the invention play be better K understood, reference is made to the accompanying drawing, of which` Figure l is a central vertical section of apparatus for producing the matrix vWithin which the metallic records are to be deposited; Fig. 2 lis a similar View of the matrix after being removed from the mold of Fig. l, and after the master has been removed therefrom; Fig: 3 is a similar View showing Aapparatus, for producing a meta? deposit Within the matrix to form the record or record Wearing surface, and l? fi: is a similar View of the completed record in its preferred form. v

ln all of these views corresponda are designated by the same -referenc merals. v The first step in the process Eonsists in the obtaining of a master record. Thief record parts diers from the ordinary' master record only in respect to the material of which it is composed. This material should be insoluble in cold acetone or amyl acetat equivalent solvent of the material i to be used for forming: the interior s of the matrix, which wili be hereinafter de scribed. Such a material suitable for making of a master record is montan wax, although other or equivalent uiatcrials may for this purpose. Having obtained such a master record l. it is coated with. e. film 2 of tough or Wear rosistiixg material. such as pyroxylin or aceto-cellulose or equiv aient material, by dipping the mast instr-nice.y to produce a coating of-pyroxylin, it may be d'pped into a five to ten per cent. solution of pyrox 'V' in a mixture of acetone and amyi acetate,

and in order to produce a coating cf acetoy f cellulose the master may be dipped in a live to ten per cent. solution of cellulose aceacetic acid. After the master has been dipped'in such a' solution, the film is dried upon andadheres to the master and when thoroughly dry the coated master is placed in a suitable mold, and a film support or backing 3 is cast around it.. The mold referred 'to n ul illustrated in Fig. 1 and comprises :reenterHV ing device a, a cylinder o, base c cap di having openings e throu gh whipjh the molten material is poured to form the .backing has a. relatively/:high coecient of expansiones* heat rac as compared to metals, and which Will 'not dissolve in the solvent which is used for rcmoving the master record as will be hereinafter described. Various materials may be used, but I have obtained desirable results by using a composition of shellac and a solid solvent for shellaczwhich melts readily into a thin fluid, such as dinitrobenzol or tetrachloronaphthalene. After the casting o eration. has been completed, the mold is ta en apart and separated from its contents, to- Wit, the master 1 with the lm 2 and backing 3 all firmly adhering to each other in a solid mass.` The master 1 is then dissolved in benzene or an .equivalent solvent Which does not dissolve either the film 2 or back ing 3. This operation may be expedited by reaming out the bulk of the master leaving only a thin shell adhering to the film 2 and then dissolving out this shell, These steps result in the matrix shown in liig. 2, com

v posed of a body or backing 3 'of considerable titi till

titi

strength, and a lining 2 of a tough or wear resisting material, the Whole having a high coeliicient' -of expansion by heat as compared with metals. ln order to obtain a metallic record from a matrix of this character, the interior and the lower end are lirs't provided with an electrically conductive coating, such as finely divided graphite or gold deposited in cacao, and the matrix is then placed in a holding frame suit-able for the application of current thereto in an electro-plating bath.` This frame is illustrated in Fig. 3, and consists of upper and lower clamping,r plates and g, held together by headed bolts Il, and wing nuts i, the matrix resting upon a Contact plate j which is electrically connected with the bolt ,7L-and leading in Wire lo. Upper and lower rings Z and m of insulating material are held by the plates f and g respectively, and conductive coatings are applied to such parts of these rings and of the plate g as it is intended shall receive a metallic deposit to form the shell 4. The anode n of copper, zinc or other suitable metal, is inserted Wit-hin the frame and connected to the wire o, and the Whole is placed in a coldV plating bath and a thin coating or shell 4 of the anode metal is plated upon a matrix and adjacent parts as shown.- The plating bath should be maintained at a constant temperature, preferably below degrees Fahrenheit. This can readily be done by means of anice jacket. The plating operation requires only a few minutes and the frame and contents are then removed from the bath, washed and placed in Warm water, whereupon the n'latrix expands and the nietallic record or shell i may he withdrawn from the same by longitudinal movement. This` shi-ll. it' of sufficient thickness, may be used comincrcially as a phonograph record, or, il it is desired to strengthen the same,

moana? it may be placed in' a revolving chuck and molten material or cement admitted to the interior thereof which upon hardening forms a backing A suitable material for this purpose is plaster of Paris. The record may of course be plated with a nonoxidizing metal such as'nickel, silver, gold, etc., to secure permanence. after the removal of the metallic shell, is uninjured and may be cleaned and dried and used in the vmanner described for an indefinite number of times for producing metallic records. y

I indthat While it is desirable to remove the 'Waxlike master from the matrix wholly or in 'part by solution, it is practicable to remove 1t by relative change of diameter when the matrix backing is made of a composi- The matrix,v

tion consisting of 140 parts of metadinitrd benzol, and 100 parts shellac. In such case Aby placing. the contents of the ymold in a refrigerating chamberV and cooling the same, the master'l contracts enough more than the matrix to disengageitself from'the coating 2 and may be withdrawn to leave the matrix. Even in this case, however, it is desirable to apply the solvent (benzene) to the bore of the matrix to remove any particles lwhich may have been torn from the surface of the master by adhesion to the coating or matrix lining.

While it is preferable to cast the baclin 3 upon the film 2 in the manner describe it is possible to cement thereon a-backing previously formed, as a cylinder of hard rubber, and to carry outv theprocess in other respects in the manner previously described.

It is also possible to dispense With,the1film` 2 and cast the material 3' directly around the master 1, but in this' case there are likely to be flaws upon the record surface o'f the matrix, and this isparticularly true of records of very fine pitch such as one two-hundredth of an inch or less. I therefore prefer to practise the process in the manner which I have fully set forth as the preferred method, the invention, however, covering all such modifications as fall Within the scope of the claims.

Having now described my invention, what I claim 1s:

iccH

1. The process of duplicating sound rec Y ords whichconsists in forming onta master record a matrix of material wihose coellicient of expansion by heat is relatively,l high as compared with metals, removing said master f from said matrix, forming a .aetallyic record on said matrix, and raising tllie temperature of said matrix to separate thesamefrom the metallic record, substantially set forth.

y 2. The process of duplicating phonograph rer-rds which consists in app ying to a master record a solution of a suitable material to form thereon a coatin a :nl '|110' to said 1, il s coating a backing of material. whos-e coetlillilil record insoluble in a solution ofpyroxylincient of expansion by heat is relatively high as compared With metals, removing said masterito leave the said coating and backing as a negative record or matrix, electroplating metal upon the surface of said matrix, and raising the temperature of the latter to separate the same from the metallic depositi.Irvt substantially as set forth.

3. The process of duplicating phonograph records which consists in forming around a ,master record a matrix of-material Whose coeeientof expansion by heat is relatively high as compared with metals, removin saidmaster therefrom, electroplating meta upon the surface of said matrix, and raising the temperature of the latter to separate the same from the metallic deposit by relative change of diameter, substantially as set forth.

4. The rocess of duplicating sound records which comprises forming a" matrix of4 non-metallic material Whose coeiicient of expansion b heat is relatively high as compared Wit' metals, electroplating' thereon a body of metal to form a metallic positive, raising the temperature of said matrix to separate the same from said positive,an'd thereupon removing the metallic positive from the matrix by relative longitudinal movement, substantially asset forth.

5. The process of duplicating phonograph records which comprises obtaining a master or its equivalent, applying thereto such a solution to formthereon a coating, a plying to said coating a backin of materia whose coeiiicient of expansion y heat is relatively high as compared with metals, removing said master to leave said coating and backmg as a negativev record or matrlx, electrorecords which com rises appl leave a matrix, substantially as set forth.

plating on said matrixa coating of metal to therefrom and removing said. positive from 4 said matrix by relative longitudinal` movement, substantially asset forth.

6. The rocess of duplicatingphonographrecordsiw ichcomprises obtaining a master record insoluble in a solution of pyroxylin or its equivalent, applying thereto such a solution to form thereonl acoating, and then removing said master to leave the said coatin as a negative recordv surface or matrix, su stantially as set forth.v l

7. The rocess of duplicating phonograph records w ich comprises-obtaining'a master record insoluble in a solution of pyroxylinl or its equivalent, applying thereto such a so-v lution to form thereon a coating, applying to said coating a backing ofmaterlal whose' coefficient of expansion by heat .is relatively '4 highas compared with metals and then removing said master wholly or 1n part bysolution to lee ve' the said coating as a negative ecod surface or matrix, substantially as set ort 8. The process of dupliatin "phonograph g to a master record of Waxli emateria a solution of pyroxylin or its equivalent' to form a coat'- ing, casting around the coating a. backing-of non-metallic material and removin said master from said coating by solution to 'This specificationv signed and 'witnessed this 3rd day pf Sept. 1909.

JonAs W. AvLsWoRTH.

Witnesses: l l y DnLps HoLonN, Dran 'SMrrm so 'y

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