US1370719A - Talking-machine record - Google Patents

Description

E. A. WIDMANN.

TALKING MACHINE RECORD. APPLlcATloN FILED MAR: 26. v|920.

'1,870,721 9, n Patented Mar. 8, 1921.

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TALKING-MACHINE RECORD.

Specification of Letters Patent.

Patented Mar. 8, 1921.

Application filed March 26, 1920. Serial No. 369,027.

T o all whom it may cof/wem.'

Be it known that I, EUGENE A. WIDMANN, a citizen of th'eUnited States, and a resident in the borough of. Brooklyn, county of Kings, city and State of New York, Whose post-office address is No. 10 Grand avenue, Brooklyn, 'New York, have invented certain new and useful Improvements in Talking-Machine Records, of which the following is a full, clear, and exact description.

My invention relates to various new and useful improvements in talking machine records and my object is to produce a record of superior quality and of low cost.

Experience has shown that shellac is the material par ecellence for use as a binder in the make-up of compositions for talking machine records, or, at least, for the Wearing surface of the same. Such compositions employing shellac as the binding ingredient thereof possess extremely valuable qualities for the purpose. They take a very sharp, clean impression from the matrix so that the record surface is smooth and free from scratch; they possess a very great degree of durabilityunder the Wearing action of the stylus which tracks the same; and they are permanent, practically non-hygroscopic and unaffected by changes in temperf ature encountered under conditions of ordinary. use. Furthermore, they do not require a lengthy heat treatment or cooling as is necessary, for instance, when phenolic condensation products are employed. Because of the presence of shellac in these compositions, lending to them the desirable qualities above referred to, they are known in the patent literature of the art as shellac-like material. These compositions' differ very largely in their make-up, the shellac being admixed with various fibers and fibrous or amorphous fillers, but they are all characterized by the presence therein of shellacl in sufficient quantity -to give to the composition the desired physical properties.

The enormous demand for shellac, largely coming fromvthe talking machine art, has madel it a very expensive material for use in compositions for talking machine records, andmany attempts have been made, therefore, to reduce the amount of shellac used and to confine the shellac-like composition to the record surface or surfaces. Thus attempts have been made to produce composite records with one or more shellac-like record surfaces, and with a non-thermo plastic center, such as paper or compositions of Wood flour with a suitable binder; but it has been found that when such a record is subjected to heavy pressure necessary to secure the impression of the matrix there is danger of the rough surface of the non, thermo plastic material being reproduced through the shellac-like layer and appearing on the actual record surface as an undesirable roughness producing scratching and other foreign sounds in the reproduction. Moreover, it-has been found that vwith such composite records, although the record surface when initially formed from the matrix 1s an exact copy thereof,the impression is not permanent and tends to be gradually effaced so that the record becomes undesirably faint.

Other attempts have been made to make composite records by applying a shellac-like layer to a paper sheet and applying the pa per sheet so coated to one or both surfaces of a cheap thermo plastic center, the paper being employed to prevent the softer and poorer material from coming through to the surface, and thus reducing the wearing qualities of the'record surface. But with these latter records the relatively rough surface of the paper is likely to be formed in the record itself. producing objectionable foreign sounds. Moreover, the records are likely to warp due to uneven expansion and contraction and difficulty has been experienced in preventing undue displacement of the thermo plastic center under the effect of the very' great pressures which are imposed in securing the record impressions.

So far as 1 know, no one has succeeded in making a composite record. with a shellac-like record surface or surfaces, having the desirable practical qualities of a record made wholly of shellac-like material. as is the common practice in the art. These composite records as heretofore made have not only lbeen rough but difficulties have been encountered, due to unequal thermo expansion and contraction, resulting in cracks and other physical defects.

`Furthermore, the manufacture of such composite records, as heretofore suggested,

involves generally an expensive reorgamza-v I tion' of factory equipment' and change of process. makingI it diicult and expensive for a concern in actual business to undertake the practical manufacture of the Same.

My improved talking machine record is one in which the record surface itself is just as smooth as when the record is made wholly of shellac-like material. lt is just as desirable as a' record made Wholly of shellac-like material because the surface with which the needle or stylus engages is composed of shellac-like material ordinarily several times thicker than the maximum depth of the record groove. It is just as durable and as no..i-hyg1o'scopic and, in its other physical properties, as vdesirable-as a record made Wholly of shellaclike material, because the additional materials employed are of the same general nature as, though much cheaper than shellac.

It is actually superior to a record made Wholly of a shellac-like material in the respect that it Will resist a highizr temperature Withoutchange than a record made of shellac-like material (as, for example, if accidentally placed near a radiator) because its melting point is somewhat higher as a whole than shellac.

It possesses thegreat advantage that it can be manufactured with the same appa-- ratus and by substantialljv the same process used in the manufacture of records of shellac-like material as now practised in the art.

My invention is based on the discovery made by me that talking machine records, having the desirable' properties indicated, can be made by using as a body or foundation' to which the shellac-like material is applied, a material practically homogeneous throughout- Whose melting or softening point is higher than that of shellac. By making a composition record mth the central portion of a higher melting or softening point than shellac, the engagement of the matrix during the process of forming the record surface will not unduly deform or displace the central portion, which therefore retains its identity Without coming through the surface or weakening by adulteration the film of shellac-like material and the impression Will thus be formed solely in the film of shellac-like material.

Materials which have found admirably adapted for the purpose and which are of a `higher melting'or softening point than shellac are Various gums and resins of the general nature of copal, kauri and dammar and known in the trade as Congo sorts. copal hard sorts. palelast india. Manila sorts, kauri, singapore, dammar, red gum. etc. These materials are all gums or resins Whose melting or softening points arehigher thanishellac and Which are hard, uniform and structureless materials. As l shall hereafter point out, in making records it may sometimes be desirable 'to formV the blaiik of a cheap material Iwith a polished surface to Which the film of shellac-like material is applied` and all the materials refered to are capable of taklnga very smooth high polish from a polished mold or matrix.

I may use for the center or body portion of my record any one of the foregoing materials or a combination of the same, or any equivalent amorphous, structureless, thermo-plastic material having a higher melting point than shellac. These 'materials all possess substantially the same coefficients ef expansion as shellac or shellac-like matei rials, so that when the record is completed, as will be explained, its coefficient of expansion is substantiallyv the same throughout and difficulties'will not be experienced due to uneyen expansion or contraction. At the same time, by properly selecting a suitable combination of these materials in proper proportion, the resulting composition can be made to have the same coefficient of expansion as shellac-like material Within 'very close limits. These gums or resins are capable of being mixedY in any desired proportion by simply melting them together.

. Instead of using one or more thermoplastic materials of the general class referred to, with higher melting or softening points than shellac. the center portion of the record may be formed of non-thermo plastic material in a finely divided condition admixed With binders so that the structure as a Whole will have a higher melting or softening pointthan shellac. And such binders themselves may'be ones haying a higher softening or melting point than shellac or a loiyer melting or softening point. so long as the composition itself is of such a character that under a temperature Vwhich softens the -hellacllike film the center of the record would be lessd affected and more firm and unyielding. so that under the effect of pressure the impression Will be formed in the shellac-like film Without unduly deforming the central portion of the record. lnstead of using gums or resins of the type referred to, either alone or in combination. l may em- U0 ploy for the purpose certain grades of fine asphalt; the melting or softening' point of which is higher than shellac.

The important properties which shall be possessed by the material or composition to which the shellac-like material is to be applied are. first. the melting or softening point shall be higher than'shellac: second, its cociiicient of expansion shall he as near that of shellac as possible: and, third. it shall be structureless and amorphous and preferably in and of itself shall be cipable of taking a smooth high polish from a polished mold or matrix. The latter'property is especially desirable when the records are 152 made by first forming the central portion or core iyith a highly polished surface to which the shellac-like material is applied. It is also important that the material to Which the shellac-like composition is applied shall not be affected by climatic changes or be subjected to mold or decomposition. If the record impression formed in the shellac-like material is sufficiently deep to produce a def- -ormation in the central material or core, it.

the diameter but slightly less in thickness than the ultimate recordto be secured; or, instead, the material may me pressed into square plates or sheets of the desired thickness from which the disks are finally cut.A Preferably, but not necessarily, the disks are pressed and formed between highly polished dies so that their surfaces will be smooth and highly polished. The disks so made are now coated on one or both sides with the shellac-like composition. This is done in any suitable way, as by applyingthe shellac-like material in a suitable liquid form like'paint and allowing it to dry on the surface of the tablet or by applying the shellaclike materialin the form of a powder, or by a transfer process by which the shellac-like material in the form of a very thin sheet or lilm is transferred to one or both surfaces of the disk. The shellac-like material being thus applied to the disk, as/explained, the record surface is impressed therein by engaging the shellac-like surface or surfaces between the matrices in a hydraulic or other press in the usual way. During this pressing operation heat is applied to soften the shellac-like material, whereby a clean-cut smooth impression will be secured without however materially softening, deforming or displacing the main portion of the record, which thus retains its integrity and preserves -its general shape and dimensions. This compression of the matrix into the shellac-like material causes the latter to be closely compressed into contact with the body portion of the disk and brings about an effective welding of the shellac-like layer or film thereto, so that practically a homogeneous structure is secured. Thus, at all points the sheIlac-like film carrying the record surface will oe supported intimately by and upon the smooth polished surface of the material of higher melting point, and hence the needle or stylus will be just as rigidly supported by the record as if it were comi posed of shellac-like material throughout.

Instead of'ma'king the record, as above described, by first forming a disk of the material of higher melting point and applying a shellac-like' film to one or both -s uraces thereof and subsequently limpressing the record grooves in the shellac-like film or films, any other suitableprocess for producing the improved record ma)Y be employed. For example, I may first make the disk or core of the material of higher melting point and then introduce the same between the two matrices of the press. introducing above and below the disk a ball or gob of the shellac-like material of the proper quantity to produce a lilm of the desired thickness. The matrices being heated and the centraldisk being also preferably heated at or near the softening point of the shellac-like material the pressure is imparted to the two matrices which thus impose sufficient pressure on the ball or gob of shellac-like material to cause the same to flow and spread evenly over the face of the disk of higher melting point. Thus, the one operation results in the formation of thc shellac-like film on the body part of the record and at the same time results in the forma tion of the record groove therein. Also the shellac-like film will under the eiiect ofheat and pressure be caused to intimately weld to or coalesce with the body part of the record so as to form a homogeneous structure.

In order that the invention may be better understood attention is directed to the accompanying drawing forming a part of this specification.

' In Figure 1 I illustrate an edge view of a portion of my improved record on an enlarged scale, indicating thereon the center portion composed of material of higher softening point than shellac7 and the two films of shellac-like material applied thereto so as to constitute practically a homogeneous structure.

In Fig. 2 I illustrate the bed and plunger of a steam heated hydraulic press, the two matrix faces thereof cooperating with a ball or gob of shellac-like material, as' above described, so that when pressure is applied these balls or gobs will be spread out and caused to adhere to the center core and the record impressionl will be simultaneously formed in the distributed shellaclike material.

Having now described my invention, what I claim as new therein and desire to secure by nLetters Patent is as follows:

1. An improved molded sound record, consisting of a practically homogeneous disk formed with a shellac-like record-surface and a body portion to which the shellaclike material is welded or coalesced, of a higher melting or softening point than shellac, substantially as set forth.

2. An improved moldedA sound record, consisting of a practically homogeneous disk formed with a shellac-like record surface and a body part to which the shellac-like material is welded or coalesced, of a structureless, amorphous material of higher melting or softening point than4 shellnc. substantially as set forth.

3. An improved molded sound record, comprising n polished disk of thermo plustic materiul of higher melting or softening point than shellnc and a shelluC-like film intimately welded to or voulesced with said disk and carrying u record surface, the record being substantially homogeneous throughout, substantially as set forth.

4. An improved molded sound record, comprising a polished disk of u thermo plastic gum or resin of higher melting or softening point than shellnc and n shellaolike film iulnmtely welded to or coalesceol wih 15 said disk. :unl Carrying a record surface., the record heilig substantially homogeneous throughout. substantially as set forh.

This specification signed and witnessed this 2nd day of March. 1920.

EUGENE A. WDMANN vitnesses CATHARINE D. JORDAN, M. E. MCNINCH.

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