US808843A - Method of manufacturing sound-records. - Google Patents

Description

No. 808,843. l PATENTED JAN. 2, 1906.

W. H. HOYT & W. J. GAVEN.

METHOD 0F MANUFACTURING SOUND RECORDS.

' APPLICATION FILED DBO. a. 1904. v

Egwdered/ 4 (Blauwe4 WWI-933292351' UNITED sTATEs PATENT FENCE.

WILLIAM HELM HOYT AND WILLIAM JOSEPH GAVEN, OF BRIDGEPORT, CONNECTICUT, ASSIGNORS TO THE BURT COMPANY, OF HACKENSACK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented Jan. 2, 1906.

Application led December 8, 1904. Serial No. 236,074.

To all whom, t may concern,.-

Be it known that we, WILLIAM HELM HoYT and WILLIAM JOSEPH GAvEN, of

Bridgeport, Connecticut, have invented a new and useful Improvement in Methods of Manufacturing Sound-Records, which invention is fully set forth in the following specification.

The present invention relates to an improvement upon the process described in our application for patent, Serial No. 212,216, filed June 11, 1904, which describes the production of pressed sound-records having the glaze (shellec, for example,) practically confined to the surface part of the record. In carrying out the invention as therein described we formed two batches of the plastic material, one containing the usual proportion of shellac, the other containing no (or a very slight quantity of) shellac. The two batches were rolled into sheets, that containing the shellac being about half the thickness of the other sheet. The two sheets were placed one upon the other and united by heat and pressure, which could be applied simultaneously with the impression of the sound-record upon the surface. In carrying out the process in that way we found that the surface sheet would not invariably flow so as to cover the tablet continuously, and the result would be an occasional record having soft spots which would quickly wear away. Furthermore, it was not easy to use always the same amount of the surface stock, thus incurring either the risk lof using too little or the waste of using more than necessary. By the present invention we remedy these difficulties completely. Instead of applying the stock to form the face of the tablet in a plastic condition we apply it in a dry state in the form of a powder, whereby a continuous layer of practically uniform thickness can be obtained. Preferably we take the composition after being well ground and mixed, as usual, and ap ly it by means of a sieve or sifter to the sur ace of the matrix, so as to cover the face thereof completely, with'a layer a proximating one-third of the thickness of t e finlshed record. On this is placed the stock which is to form the body part of the record, and hydraulic pressure is then applied, as usual.

The operation may be most conveniently carried out by means of a circular sieve or sifter of well-known construction having the same diameter as the matrix. Placing such a sifter above the matrix and giving a turn to the clearing device in the sifter causes the deposit on the matrix of a layer of the composition of the required thickness. This operation can be performed very expeditiously, and the results are entirely satisfactory. Preferably we use for this operation the sifter or sieve described in our application, Serial No. 289,936, filed January 6, 1905.

The accompanying drawing illustrates conventionally the tablet resulting from our method, the relative thickness of the layer of powdered glaze being slightly exaggerated.

Having now fully described our said invention, we claim- 1. The method of forming a sound-record tablet by applying upon the surface of the die or matrix a layer of plastic material in a dry and finely-divided state, and a layer of similar material in a plastic state, and uniting the two by heat and pressure.

2. The method of forming a sound-record tablet by applying pressure to two batches or layers of plastic material, one layer being in the form of a dry powder, the other in a plastic condition.

3. The method of forming a compressed sound-record by applying upon the surface of a suitable matrix or die a layer of finelydivided material containing a glaze, applying to said layer a batch of similar material essentially free from glaze, and uniting the two layers by means of heat and pressure.

In testimony whereof we have signed this specification in the presence of two subscribing witnesses.

WILLIAM HELM HOYT. WILLIAM JOSEPH GAVEN.

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