US2094280A - Fabrication of records - Google Patents

Description

Patented `sept. 21.*,Y 1937 "PATENT ori-ICE FABRICATION or nrzcomisV I Barton A. Proctor, LarohmonL'N. Y., .assignor toA B. A. Proctor Company, Inc., New York, N. Y., a corporation oi New York Application August 27, 1935, Serial N0. 38,032

Claims.

Some of the above diiilculties and disadvan-,

tages are inherent in the present day practice of engraving the original on a wax record blank and then applying to this wax record a thin film of graphite, on which a layer of metal is electrodeposited to form a metal negative for stamping outvrecord blanks.

'Ihe disadvantages of this process may be summarized in part as follows: the wax records are very delicate and affected detrimentally by temperature changes; they require careful preparation, including a shaving operation which consumes time `and demands special skill; the surface of the record is easily marred so that very careful handling of the record is necessary.

After recordation, the working of the graphite into the wax, preparatory to electroplating, in-

jures the record and impairs the fidelity of the iinal record. The electroplating operation takes a long time, in some cases as much as 18 to 20 hours. Only one plated record can ordinarily be made from the original wax record. 'I'he surface of the plated negativeA record is granular and relatively coarse, thus causing further injury to the fidelity of the reproduction.

In this process, moreover, there can be no playing back of the record until the entire 40 process has been completed. Hence, if there has been a fault in the original recording it'persists as a latent defect throughout the whole cycle of operations and only emerges when correction is impossible and a new recording must be effooted, so that the expense is doubled, and in some cases the opportunity for recording will have been wasted irrevocably.

Ina co-pending applicationof the present applicant and Ferdinand C. W. Thiede, disclosure is made of a novel process in which the chief difficulties of the conventional wax-record method above recited have been'overcome, by the provision for making the original record,.not in soft wax, as in the prior art, but in a metal, such as sheet aluminum, which possesses satisfactory characteristics so far as the resistance to heat and the capacity for withstanding pressure are concerned, and this and other metals which may be purchased in sheet formI with a polished surface, in condition for use, have the advantage 5 over wax of yielding a record which is unbreakable, impervious to moisture and insensitive to temperature changes. They are inexpensive. and

do not require the high degree oi skill that is necessary for recordation on wax. 10

Recordation on solid metal original records is, however, not wholly satisfactory, for the reason that the engraving tool used in recordation necessarily displaces the metal in such a way as to form furrows on edges of metal so that the sound 15 track lacks the smoothness of that made in a more plastic material, this being especially characteristic of the deformation accompanying inscription oi the sound modulations in the lateral walls of the sound groove or track according to 20 conventional methods.

It is an object of the present invention to provide a process which will be both cheaper and' quicker than the waxfprocess; will have the advantages which characterize the use of a plastic 25 material in recordation without the disadvantages due to the unduly soft nature of Wax; and will possess to a desirable extent the properties which make for permanence in a solidmetal reoord While avoiding thev intrinsic limitations of a 30 hard grained material such as solid metal.

According to the present invention, the original record is made, not in the soft wax, but in a material having tough, elastic, smooth and impression-retaining properties which are charac- 35,

teristic of a iilm of cellulose acetate.

Another object of the invention is to provide the film of such material with a backing comprising a layer or layers of material which enhance the yieldingly resistant response of the film-to 40 the bending action of the recording tool, which acts to bend successive portions of the lm exclusively in a direction which leaves the operating surface free from projections other than those suitable for the intended use, the forma- 45 tion being so performed that the deformed ilm, after production of the sound-track, retains its original integrity, no cutting of the material having attended the deformation, and thus the characteristic smooth continuity of the film surface 50 remains unbroken. l E

In pursuance of the general object of the invention, a particular object is to provide a method of fabricating sound records which comprises the step of formngthe original sound track by 55 yord from said original record, using moldable, infusible, insoluble material under requisite conditions of pressure and temperature so as to cause said material to form a faithful mold of said sound track, then after said last-named material has attained adequate hardness, using said negative record for obtaining the final records with suitable thermoplastic material.

Other objects and advantages will appear as the description of the particular physical embodiment selected to illustrate the invention progresses, and the novel features will be par? ticularly pointed out in the appended claims.

In describingthe invention in detail and the particular embodiment selected to illustrate the invention, reference will be had to the accompanying drawing and the several views thereof in which like characters of reference designate like parts throughout the several views, and in which: I

Fig. 1 is a plan view of a sound record in the fabrication of which the present invention has been embodied;

Fig. 2 is a fragmentary, detail view in vertical section, taken on any radius of the record as shown in Fig. 1, and upon a larger scale; and

Fig. 3 is a view similar to Fig. 2, illustrating a modification.

In one embodiment of the invention selected for illustration and description the reference character I designates a film of material, vsuch as cellulose acetate material as that possesses-certain characteristics which are highly desirable in carrying the invention into eect, and including such properties as toughness, elasticity or tenacity, smoothness of surface, the capacity for being deformed bodily by a bending tool in recordation, while retaining its integrity and smoothness of surface; and also characterized by retentiveness of the record track produced by bending, and having freedom from furrows and ridges other than the grooves suitable for the intended use.

While I have found a film of cellulose acetate satisfactorily useful for the purpose set forth, it is not intended to exclude a film of analogous material possessing the desired characteristics to a requisite degree; alsometal foils such as aluminum foil, for example, may be used.

In pursuance of another stated object of the invention, provision is made of a backing susceptible of supporting the record film during the step of recordation also during subsequent steps of the method, and of enhancing the yieldingly resistant characteristics of the film while under bending deformation by the recording tool.

A base disc or layer 2 of suitable material, such` as metal, heavy cardboard, or a iictile material such` as a thermosetting resin, may be provided, to afford desirable rigidity, and resistance to pressures employed at various stages in the fabrication of such records, and between this base 2 and the film I, provision is made of one or more layers of .a material or materials adapted to afford yieldingly resistant support to the film I during recordation, and thereafter to afford a substantially unyielding support thereto, although this expression is not intended to exclude a certain elasticity whichmay be desirable to avoid any tendency of the film to crack under undue presisure in the event of failure to exercise proper care in subsequent steps of the method.

In the drawing this layer, which serves to bind the .film I to the backing 2, is designated 3' and maybe considered as comprising a, bituminous substance, such as a. high-grade asphaltum, or one of the synthetic resins or resinous materials such as bakelite or a. material of the urea-formaldehyde, or otherreaction groups, of a composition suitable to afford the desired yieldingly resistant characteristic during deformation by the bending tool, and subsequent support of a substantially unyielding character. with such modulating elasticity as may be readily provided for by those skilled in the plastic arts.

Fig. 3 of the drawing show's in detail at 4 a layer of somewhat analogous material which is intended to interpose a characteristic resistance to lateral or spreading effect of the walls 5 of the groove T which constitutes the sound track. Paper impregnated with any suitable thermosetting material such as bakelite may be used.

It has been observed by me that, in the step of recordation, there is a tendency of the recording tool to .push the groove wall away from it in a way that tends to impair the fidelity of recording and while it is not desirable to hold the material of the film I tooV rigidly, on account of the danger of permitting its rupture, I have conceived the novel provision of a laminated backing in which the layer 3, already described, permits so much of the lateral yieldingeffect as may be necessary to avoid rupture, while the layer 4 prevents an amount of lateral yielding which might interfere with fidelity to the rendition.

The layer 3, as in Fig. 2, or the layer 4, as in Fig. 3, is of course secured suitably to the support 2 by suitable adhesive means, indicated by the heavier joint line 6, it being understood, that the adhesive` constituent may be provided in the composition of the layer 3 or of the layer 4 and similarly that suitable provision will be made for insuring adhesion of the film I to the contiguous surface of the backing layer 3. A bituminous material, such as asphaltum, may be selected that will afford the exact adhesive effect required.

Fig. 1 shows a complete original record with a sound track ready for use as a master record, and it is to be noted that in the production of this record, the 'same can be played back at any stage of the recordation so that any flaw of recordation, or of rendition, can be detected at a desirably early stage, and before the defect becomes irremediable.

The original record, designated generally as R in Fig. 1 is capable of being used as a matrix in any conventional mode of producing a negative for subsequent utilization in mass production of the final records for distribution.

A desirable, and now preferred method for carrying out this and subsequent steps in the fabrication of such final sound records is disclosed and claimed in the aforesaid co-pending application Serial No. 716,916, filed March 22, 1934 to winch reference may be made for a more complete description of desirable details.

For the present disclosure, it is suiiicient to summarize the procedure as follows:

The sound track is utilized as a matrix by placing the record R in a press, for the making of an intermediate or negative record. To accomplish suitable condensation or thermosetting product is filled in the appropriate die of the press and the record R is placed face down upon such layer. The die is now heated to the appropriate temperature for the material used as previously mentioned, and the upper and lower dies of the press brought together under the proper pressure.

The result of the foregoing operations is to produce a negative impression or record of the original record R. When this record has been fully cured it is used as the matrix for the making of the inal records, preferably in a known or suitable thermoplastic material, and in the conventional or any suitable manner.

It should be understood that the invention is not limited to disc records such as illustrated in Fig. 1 but that it may also be applied to cylinder records and tape records. Fig. 2 or 3` may be considered a cross-section of a fragment of each of these records.

I have described what I believe to be the best embodiments of my invention. I do not wish, however, to be coniined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. As a new article of manufacture, a record blank comprising a lm of tough, smooth, irnpression-retaining material, a supporting base.

layer, and a deformable intermediate layer of plastic material slightly thicker than the depth of the sound record track to be formed in said iilm.

2. As a new article of manufacture, a record blank comprising a iilm of tough, smooth, im-A pression-retaining material, a non-compressible supporting base layer, and an intermediate layer of plastic material slightly thicker than the depth of the sound record track to be formed in said lm, said blank being further characterized by a. I

formed in said film, said blank being further characterized by having said intermediate layer formed of sticky material.

4. As a new article of manufacture, a record of the class described comprising a film of tough,

smooth, impression-retaining material, a supporting base layer, and an intermediate layer of plastic material, said film being deformed bodily into said intermediate layer` by a sound track groove the bottom of which extends near to said supporting base, while the plastic material is in close proximity to the lateral walls of said groove, and Vsaid deformed iilm being substantially self-sustaining with respect to strains encountered in replication and in playing said record. A

5; A novel method of forming sound record comprising the step of deforming a illm of tough,

smooth, impression-retaining materialI into a layer of sticky plastic material of a thickness slightly greater than the depth of the sound track groove being formed,and against a supporting base layer adapted to cause the circumf jacent plastic material of the intermediate layer to flow around the lateral walls ol.' the sound groove.

BARTQN A. PROCTOR.

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