US878547A - Production of disk sound-records. - Google Patents

Description

No. 878,547. PATENTBD PEB.11, 1908 T. H. MACDONALD. PRODUGTIUN OF DISK SOUND RECORDS.

APPLIGATION FILED SEPT. 8, 1906.

BODY OF EARTHY 05? h uwrmnngjmm I TPAPER msc com'mn I "WITH SHELL/M COMPOSITION 3 rum u ['01 Climate m invented a new and useful Production of THOMAS H. MACDONALD, BRIGE'TEPORI, CONNECTICUT, .l-iSSli lNtl lt TO AMERICAN GRAYHOPHONE C-f lfdidll l', OF BR IDGEPOIL'T, (JUNNEU'IIUUT, A CORPORATION OF WEST VIRGINIA.

PRGDUCTZON OF DISK SO'QND-BECORD".

Specification of Letters Patent.

Patented Feb. 11, 1908.

App ication filed September 8.1906. Serial No. 333,812.

T 0 all whom it may concern:

Be it known that I, 'iuotrss H. MAonoN- ALD, a citizen of the United States, and a resident of Bridgeport, Connecticut, have Disk Sound Records, which improvement is full set forth in the following specification.

' The present invcntionrela more particularly to the manufacture of dish s nnul-records, and has for its object to i-heapcn the production of such records, and at the same time to improve their quality, especially in re spect to strength, durability, and uniformity of product.

Sound-records of the disk type are, and for many years have been, made of compositions of heavy earthy material compacted by means of shellac. Various earthy mate- I rials have been used, in varying pro ortions, each manufacturer having his own formula, but shellac is an essential ingredient of all, and is that which contributes chiefly to the .cost of the composition. Generally, the shellac is distributed. uniformly tlusmighout the mass, :its primary purpose heinp -s a binding material. It has, however, been discovered that the essential advantage of the presence of shellac in hese cmnpositions when used for sound-recm'ds, is the gluzed surface imparted by that material, and for which no substitute has as yet oecn found. The effect of the peculiar surface due to the resence of shellac is to cause the reproduclng stylus to slide easily and smoothly along the record r'oove, thus produciin, good tone uality and also prolonging the-life time of t e record. Without shellac in proper pro portion in the surface, the reproduction would be extremely harsh, and the record would be destroyed after a very few repro ductions. 'As the result of this discovery of the special function of the shellac it has been found that sound1'cco1'i,ls of the best quality can be produced by confining shellac sub stantially to the surface of the record tablet, and em loying armther material a binder in the ody of the tablet. .he improvement just referred to is desc ibed in the lioyt and Gaven Patents Nos. 30-,5-12, 80$,l.-'l3, and 809,263, all dated January 2, 1906. The result is a tablet of practically homogeneous composition quite indistinguishable in aparance from, and exhibiting the same lacture as, sound records wherein shellac is used uniformly throughout the tablet. E-y

this Hoyt and (laven processa very large economy is effected in the manufacture of the souml-1'ecords.

In carrying out the Hoyt and Gaven process care must be taken to form a continuous layer of the smfacing material over the inforior body material. Should the latter come to the surface, even for a very small area, a soft s mt would result, and the sound-record woulu be defective. As a precaution against such possibility, and against lack of care on the part of the iwn'hnian, the surface layer is made of greater thickness than is necessary relative to ,the depth of the record-groove.

in carrying out the present invention, paper (preferably hard paper) is cut into disks of proper size, and i. may then proceed either to coat the paper with shellac solution and dust with shellac powder, or I may take the dry paper and dust it with the dry snellac powder and then apply heat. The shellac powder employed may he more or less pure shellac, or may consist. of shellac and other ingredients and any desired coloring matter, and the term shellac powder as hereinafter employed is intended to include both the pure shellac and shellac with other ingredients. in either case the result is an article that son'ipwhat resembles ordinary sand-paper in appearance, the particles or granules of the shellac powder adhering firmly and closely to the surface of the paper. 'lhese coated paper disks may be prepared in quantities and delivered to the workmen when needed for making records. To complete the record, the shellac-dusted paper disk is placed face downward upon the heated matrix, a sullicicnt amount of plastic backing-material is placed on the back of the paper, and the whole is pressed in the usual manner. The finished record shows no sign of the paper, which is concealed by the surfacing of the shellac powder. This shellac powder may he made of more or less pure shellac, or may contain other ingredients such as celluloid, etc, and any desired coloring matter. lfhirthormorc, i: may apply a disk of paper at the hack of the backingnuiterial, so that the finished article will have one or two (if the second sheet of paper be employed) sheets as a binder, which serves to reinforce and stiller. the record.

Instead of applying the backing to the shellac-dusted paper While the latter is upon the matrix and compressing the whole to as great economy; The amount of powder necessary to coat the paper is only from onehalf to three-quarters of an ounce, whereas the smallest amount that can be employed under the present process is about two ounces;

moreover, in making such records in a factory employing hundreds of pressmen, there is inevitably considerable waste, owing to carelessness, but in carrying out my present invention the preparation of the shellacdusted paper would be in a special room and by men trained to do just that work and nothing else. This shows a saving of at least seventy-five per cent. of shellac-powder which is an element of great expense in the making of sound-records. The second advantage is that records can be made more rapidly in this manner than in the old way. A third advantage is, as already indicated, that the sheet of paper seems to stiffen the record and renders it more durable.

In the accompanying drawing is shown part of a press for pressingdisk soundrecords, and also a disk of paper coated with the record-surface material, and a backing of earthy (or other suitable plastic) material, therein, illustrating the method by which disk sound-records are produced according to the present invention.

The product of the above-described process is not claimed herein, bein made the subject-matter of a separate app ioation.

Having thus described my invention, I claim:

1. The process which consists in coating sheets of paper with plastic material, and

uniting two or more coated. sheets to form a Henna-r1 talxlnf.

erase? 2; The process of manufacturing disk sound-records, which consists of applying shellac-powder to a disk of paper, applying the same upon a recordanatriir, applying suitable backing-material upon the back of the paper, and compressing the same.

3. The process of manufacturing disk sound-records, which consistsof applying shellac-powder to a disk of paper, applying the same upon a record-matrix, applying suitable backing-material upon the hack of the paper, and compressing the same under heat.

4. The process of manufacturing disk sound-records, which consists of applying a shellac solution to a disk of paper, dusting the same with shellac powder, drying it, and compressing the same with a suite hie backing against a record-matrix.

5. The process of manufacturing disk sound-records, which consists of applying a shellac solution to a disk of paper, dusting the samewith shellac powder, dryin it, and compressing the same with a suitable backing against a record-matriX in the presence of heat.

6. The process of manufacturing a disk sound-record, which consists of applying shellac powder to a paper disk, heating the same causing it to adhere, and subsequently compressing the same with a suitable backing against a record-matrix. I

7. The process of manufacturing disk sound-records, which consists of preparing a shellac dusted paper, applying the same to a suitable backing, and compressing the whole against a record-matrix.

8. The process of manufacturing disk sound-records, which consists of preparing a shellac-dusted paper, applying the same to a suitable backing, and compressing the whole ag inst a record-matrix under heat.

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

THUMAS H. MACDONALD.

Witnesses:

A. B. Kno'een, R. T. PITT

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