US1146413A

US1146413A - Method for producing tablets for sound-records.

Info

Publication number: US1146413A
Application number: US66688811A
Authority: US
Inventors: Thomas A Edison
Original assignee: NEW JERSEY PATENT CO
Current assignee: NEW JERSEY PATENT CO
Priority date: 1911-12-20
Filing date: 1911-12-20
Publication date: 1915-07-13
Anticipated expiration: 1932-07-13

Description

T. A. EDISON.

METHOD FOR PRODUCING TABLETS FOR SOUND-RECORDS.

APPLICATION FILED DEC. 20, 19M.

Llfifil 3e, Patented July 13, 1915.

THOMAS A. EDISON, OF LLEWELLYN BARK, WEST ORANGE, NEW JERSEY, ASSIGNOR TO NEW JERSEY PATENT COMPANY, OF WEST ORANGE, NEW JERSEY, A CORPORA- TION OF NEW JERSEY.

Specification of Letters Iatent.

Patented July 13, 1915 Application filed December 20, 1911. Serial No. 686,888.

To all whom it mag concern:

Be it known that I, THOMAS A. EDIsoN, a citizen of the United States, and a resident of Llewellyn Park, West Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Method for Producing Tablets for Sound-Records, of which the following is a description.

My invention relates to methods and appara-tus for producing tablets for sound records, more particularly for sound records of the flat or disk type having a surface of an exceedingly hard material such, for example, as the condensation products, which form the subject matter of the U. S. Patents of Jonas W. Aylsworth, Nos. 1,102,630, 1,020,593, 1,098,608 and 1,040,137, the method only being claimed in this case. In pressing a blank tablet of this type into the record matrix, unless the tablet or the base or backing therefor is of substantially uniform density throughout, it is practically impossible on account of the excessive pressure in the hard spots and the deficlency of pressure in the soft spots to obtain a perfect impression over the entire record surface. Furthermore, I have found in practice that if an ordinary mass of powdered material or stock of substantially uniform thickness is placed in a mold between the ordinary rigid mold plates, it is practically impossible to obtain the necessary evenness or uniformity in the density of the tablet, the unevenness being apparently due to the fact that the powdered material lies more compactly in some places than in others.

The principal object of my invention is to provide an improved process and apparatus whereby a tablet having the. necessary uniformity of density may be readily obtained from powdered material or stock.

Other objects of my invention will appear more fully in the following specification and appended claims.

In conformity with my invention, the material or stock from which the tablet is molded is placed in a powdered condition in the mold and is there subjected to a uniform pressure applied insuch a way as to compact the stock to a mass of substantially uniform density. After this, the surface of the stock is evened off in any suitable way record impression.

way so long as it acts uniformly over thewhole of the exposed surface of the stock in the mold, I prefer to apply the same by a fluid, such as air, .under pressure; as such a pressure acts readily upon all portions of the surface of the stock, regardless of the irregularities therein. In order to prevent scattering of the powdered material by the air or other fluid employed, I preferably apply the fiuid pressure to the back of a flexible membrane or diaphragm of suitable material, such as rubber, adapted to engage the surface of the stock.

After the stock is compacted, as described above, to amass of uniform density, the

surface thereof to which the pressure has been applied is found to be undulatory or covered with high and low spots. To even off this surface I preferably again fill the mold, after which the stock may be molded under heat and pressure to the desired shape. The surface of the tablet is now provided with a veneer or veneers of impressible material adapted to receive the Although this veneer may be applied in any suitable way, I pre fer to apply the same by the process set forth in an application of Jonas W. Aylsworth, Serial No. 579,130, filed August 26, 1910, and entitled Method of molding sound records and other objects. In accordance with this process, the veneer is formed by coating the material of which the same is composed upon the surface of a blank mold, the tablet to be coated being pressed into contact with the coating in the mold with the application of suflicient heat to cause the coating to firmly adhere to the tablet. After this, the coated tablet may be removed from the mold and pressed with sufiicient application of heat into a suitable record mold to cause the sound record to be formed on the surface thereof. In order to cause the surface veneer to adhere firmly to the rough backing, I preferably cover the latter, prior to the transfer of the Veneer, with a very thin coating of the material of which the veneer is formed. This coating should be pressed into the rough tablet in order to completely fill the surface pores thereof.

In order that my inve ion may be more fully understood, attention is hereby directed to the accompanying drawing forming a part of this s ecification and illustrating various steps 0 my improved process and the ap aratus for carrying the same into effect.

11 the drawings, Figures 1 and 2 represent central vertical sectional views of the lower mold member filled with stock and covered with one form of my improved apparatus for compacting the stock, the dotted lines in these two figures indicating the respective positions of the flexible diaphragm or membrane after successive compactings. Fig. 3 represents a similar view of the complete mold after the formation of the rou h tablet. Fig. 4 illustrates the rough tab et covered with a thin coating of the surface material prior to the application of surface veneers to the opposite faces thereof. Fig. 5 represents a similar view of the coated tablet placed in a mold for compressing the coating into the tablet and for forming the peri hery of the latter. Fig. 6 represents a similar view of the apparatus for securing the surface veneers to the tablet, the tablet and the veneers being shown in position in the apparatus.

As shown in the drawings, the numeral 1 indicates the base of a mold having a centering pin 2, and a recess 3 of uniform depth in which the stock or material 4 to be molded is placed. A member 5 provided with a recess 6 is adapted to rest on the base of the mold with the recess 6 above the recess 3, the former recess being covered by a flexible membrane or diaphragm 7, forming thereby a closed chamber in the member 5. The numeral 8 designates a suitable air or fluid inlet for the said chamber. The membrane 7 is preferably provided with an upwardly directed portion 9 engaging firmly in a pcripheral recess 10 in the member 5 whereby the membrane or diaphragm 7 is firmly secured to the member 5. If the said membrane is made of a yieldable material such as rubber, the contraction of the same when stretched over the member 5 will be suflicient to draw the flange 9 into close contact with the recess 10. The membrane 7 extends preferably across the portion of the member 5 adapted to engage the base of the mold so that when the said member is held in position on the said base by a suitable pressure applying member 11, the membrane because of its yielding character will form a tight joint between the base of the mold and the member 5.

In carrying out my improved process, the base of the mold is pre erably filled with powdered stock, after which the compacting device above described is placed above the same and held firmly thereon by the member 11, fluid under pressure being thereupon in troduced from any suitable source through the inlet 8 into the chamber above the membrane 7 which is thereby pressed upon the record material or stock to compact the same in the mold. By reason of the uniformity of the pressure u on the upper surface of the membrane an the ability of the latter to conform to the exact shape of the upper surface of the stock, the latter is compacted to a mass having a substantially uniform density throughout, the position of the membrane after this operation being shown in dotted lines in Fig. 1. The member 5 and the parts connected thereto are now removed from the top of the mold and the latter is again filled and leveled off with powdered stock to even off the surface of the latter. This operation of compacting the stock and evening off the upper surface thereof may be repeated any desired number of times, but, as above stated, I have found in practice that satisfactory results are obtained when the stock is compacted and evened off a single time. In Fig. 2, the dotted lines indicate roughly the position of the diaphragm or membrane after a second compacting operation. After the material has been suitablv compacted, the upper member 12 of the mold is forced downwardly upon the stock, suflicient heat being applied to cause the latter to become slightly plastic; so that after cooling, a. rough I' klnt f bstantially uniform density and thickness is obtained.

The composition for the rough tablet may be mixtures of wood pulp or other filling agents and a fusible condensation product such as the wellknown shellac substitutes and other substances, which are referred to by the term phenol resin in applications of Jonas W. Aylsworth, Serial Nos. 496,060

- and 541,764, the term phenol resin being intended to include cresol and other equivalents of phenol. A suitable composition may be formed from the ordinary shellac mixtures with wood pulp. Any other suitable composition may be employed. The rough blank or tablet having been obtained, the same is provided with a thin coating of the material which is to constitute the impressible surface of the tablet, this coating being shown at 13 in Fig. 4. This material may be and preferably is the enamel lacquer or varnish described in application of Jonas W. Aylsworth, Serial No. 543,239,. which lacquer or varnish comprises broadly-a fusible resin of phenolic origin, which has mixed therewith a substance which is adapted to react with the resin upon the application of sufiicient heat to form a hard insoluble condensation product, the lacquer or varnish also containing a plasticity ingredient whereby it is adapted after hardening to receive a sound record impression upon application of suflicient heat. This varnish 1 "13 is preferablylsprayed onto the rough tabpress the latter between the two plates 14 and 15 of a mold, sufficient heat being applied to permit the ready forming of the periphery ofthe tablet, asindicated in Fig. 5, but notto harden the' varnish. Blank molds 16 and 17 are now coated, preferably in the same manner as the rough blank, with a solution of thesurface material. These molds havingbeen coated, the same are dried; and the rough tablet is then pressed between the same in contact with the surfacing layers or veneers formed upon the same, asfclearly indicated in Fig. 6. In the saidfigure, thernumeral 18 represents the "lower 'memberof a press. It is understood that during the operation sufiicient heat is applied to causefthe welding of the surface veneers to the blank and the transfer of the said veneersto the rough blank or tablet upon the :cooling and withdrawal of the same from the mold. If the enamel lacquer or varnish referred to above is employed for the surfacing materiahthe same may be converted on the application of heat into a final infusible insoluble refractory product. The heat to cause this transformation may be applied before the veneers are transferred to the rough tablet or blank, or the same may be applied during the said operation. I, however, consider the former method preferable because the residues of the solvent employed in making the varnish are thereby permitted to escape more readily. The heating is preferably done in successive stages beginning at about 120 F. and ending at 220 F. or higher according to the nature of the particular enamel used. When the record blank is made in the manner described above, I have found that an accurate sound record may be impressed therein regard%ess of the hardness of the surface materia While I have illustrated the application of surface coatings to both of the faces of the tablet, it is evident that if desired only one face of the tablet need be coated. Numerous other modifications may be made in the process and also the apparatus above described without departing from the spirit of my invention, the latter being limited only as defined by the terms of the appended claims.

What I claim as new and desire to protect by Letters Patent of the United States is as follows:

1. The process of making tablets for sound records, which comprises placing in a mold a quantity of finely divided stock, pressing the same to a compact mass having a substantially uniform density throughout, evening off the surface of the compacted mass, and compressing the same with the application of heat to form a tablet of desired shape, substantially as described.

2. The process of making tablets for sound records, which comprises placing in a mold a quantity of finely divided stock, forming the same into a compacted mass having a substantially uniform density throughout, evening off the surface of the compacted mass to form a mass of stock of uniform thickness, and compressing the same with the application of heat to form a tablet of desired shape, substantially as described.

3. The process of making tablets for sound records, which comprises placing in a mold a quantity of powdered stock, compressing the same to a compact mass having a substantially uniform density throughout, evening off the surface of the compacted mass with additional powdered stock, and compressing the same with the application of heat to form a tablet of desired shape,

substantially as set forth.

4. The process of making tablets for sound records, which comprises placing into a mold a quantity of powdered stock, compact-ing and forming the same into a mass havlng an even upper surface and a substantially uniform density throughout, com pressing the same with the application of heat to form a tablet of desired shape, and applying to saidtablet a veneer of hard impressible record material, substantially as set forth.

5. The process of making record tablets which comprises placing into a mold a quantity of powdered material which is plastic when hot and hard when cold, compacting and forming the same into a mass having a comparatively even upper surface and a substantially uniform density throughout, compressing the same with the application of heat to form a tablet of desired shape, and applying to said tablet a veneer of material which becomes slightly softened but not sufficiently plastic to flow when hot, substantially as set forth.

6. The process of making tablets for sound records, which comprises placing in a mold a quantity of powdered stock, compressing the same by means of fluid pressure to a compact mass, evening off the surface of the compacted mass, and compressing the same with the application of heat to form a tablet of desired shape, substantially as set forth.

7. The process of making tablets for sound records, which comprises placing in a mold a quantity of powdered stock, applying a flexible covering to the top of said stock, compressing the latter to a compact mass by the application of fluid pressure to the said covering, evening ofit the surface of the compacted mass, and compressing the same with the application of heat to form a tablet of desired shape, substantially as set forth. a

8. The process of making tablets for sound records, which comprises placing in a mold a quantity of powdered stock, applying a flexible covering to the top of said stock, compressing the latter to a compact mass by the application of fluid pressure to the said covering, evening off the surface of the compacted mass, compressing the same with the application of heat to form a tablet of desired shape, and applying to said tablet a veneer of hard impressible record material, substantially as set forth.

9. The process of making tablets for sound records or the like, which comprises placing in a mold a quantity of powdered stock, applying a yielding covering to the top of said stock, compressing the atter to a compact mass by the application of pressure to said covering, evening off the surface of the compacted mass, and compressing the same with the application of heat to form a tablet of desired shape, substantially as set forth.

10. The process of making tablets for sound records or the like which comprises v placing in a mold a quantit of finely divide stock comprising a ler and a binder therefor, compacting the same to a. mass having substantially uniform density throughout, evening off the surface of thecompacted mass, and compressing the same with'the application of heat to form a tablet of desired shape, substantially as set forth.

11. The process of making tablets for sound records or the like which comprises placing in a mold a quantity of finely divided stock comprising a ler and a phenolic binder therefor, compactin the same to a mass having substantially umform density throughout, evening off the surface of the compacted mass, and compressin the same with the application of heat to orm a tablet of desired shape, substantially as set forth.

12. The process of making tablets for sound records or the like which comprises placing in a mold a quantit of finely divided stock comprising a ller and a binder therefor, compacting the same to a mass having substantially uniform density throughout, evening 011 the surface of the compacted mass, compressing the same with the application of heat to form a tablet of desired shape, and applying a surface veneer to said tablet, substantially as set forth.

This specification signed and witnessed this 19th day of December 1911.

THOS. A. EDISON.

Witnesses: FREDERICK BACHMANN, ANNA R. KLEHM.