US1481461A - Phonogram blank - Google Patents

Description

V. EMERQQM PHONOCRAM BLANK wie@ om. 16, 1918 ulSu'r1511 srarizs' vIcToa H. EMERSON, or NEW YORK, N. Y.,'AssxGNon, BY MmNn nssIoNMENTa- To METAL anconnINe mso COMPANY, INC., .nl-'CORPORATION or New YORK.

P HONOGRAM BLANK.

Appnnon and' October 1s, 1919. ,semi No. 331,141.

T0 all whom t may concern.:

,Be it known that l, VICTOR H. EMERSON, a citizen of the United States, residin at the city, county, and State of New Ork, have invented new and useful Improvements in Phonogram Blanks, of which the followinilis a specification.

y invention 'relates to apparatus for reducing sound records, and has for an oblject the production of a blank that may be employed in forming a record groove adapted to receive undulations upon its upper edges only.

I have in a co-pending application, Serial No. 331,146, disclosed a process for forming in the top edges of a non-undulatory groove sound undulations by means of an ordinary phonograph reproducing device, and also for a record, the product of my said process. V While the record of m co-pending application may be produce by a process emplo ing a simple form of groove, it is found hig ly advantageous to trace the record formed therein if'the surfaces adjacent the groove beslightly raised so as to mininnze the mass of material topbe indented in forming the type of groove hereinabove described,

.. namely, having, its undulatory walls thus limited to the upper surfaces of the groove. Therefore my present invention described in general terms, comprises a blank for making original sound records having a groove formed with upturned lips at eitherside thereof. The accompanying drawings illustrate a preferred form of my invention, of which-- .Figure 1 is a plan view of a blank of` my invention for producing a disk sound record having the non-undulatory spiral record shown in the surface thereof; and

Fi 2 is an enlarged fragmentary sectiona view showing in perspective a pre ferred vnon-undulatory groove of my invention.

Referring to the drawings, the numeral 1 represents a disk preferably made of a suitable metal for recording therein sound waves, such as copper or other metal having a comparatively soft metallic body for receiving and retaining undulations made by a relativel blunt or rounded tracing point.

Zinc an lead may be employed with good results as the body material of my improved blank, yet L find cop er in many res ects superior to other meta lic substances and use itin preference generally over all other materials.

The groove 2 conforms to a lain spiral sunk into the fiat surface of the isk 1 which may have any convenient form as determined by the shape of the cutting or tracing'tool with which it may be formed, providing -that the top portions 3 of each side wall shall be approximately vertical and extend upwardly beyond the plane of the disk blank so as to form the sharp-edged lip 5v with the surface 4, inclined at approximately 45 degrees to the surface 3. .y

.The lip 5 is formed upon both sides of the groove of substantially'equal height and size and is relatively narrow as com ared with the width of the groove itself.

at is to.

say, the roove properma have greater orr less dept as may suit ot er requirements, but the size and shape of the ridges 5 at respective sides must not only be equal and oppositely disposed but will equal in height and width the average depth lor amplitude` of the sound undulations to be recorded therein.

Thus in Fig. 2 of the drawing a relatively wide and deep groove is shown, while the fin-like edges are adapted to receive undulations along. the top portion of the groove, leaving the bottom free for other uses or purposes, such for example as the segregation 'of dust particles andforeign matter that interfere with ideal phonographic reproduction.

The angular pointed edge 5, if made in copper, for example, will, `because of its narrow bod receive to the full depth of its vibrations t e indentations of a blunt tracing oint for recording the sound waves therein; and furthermore by maintaining the declivity of substantially 45 degrees for the inclined surfaces 4 the height of the edge 5 may be varied without fundamentally altering the adaptability to receive the wavev undulations for which it is designed.

The purpose of my disk blank is to provide a blank that may be employed in connection witha'n ordinary phonograph for recording sound waves thereon. This is accomplished b inserting in the sound box a tracing bal or similar reproducin point of greater diametral width than t e distance separating the lips 5 of the respective grooves and then placing the disk blank l upon the turntable of the phonograph.

The Weight of the sound box will carry the ball tracing point of the phonograph down into the material suilicientl)7 in case of recording laterally so as to insure itswith a spiral groove having side walls substantially vertical at their tops, and extending above the surface of the blank and inclined surfaces converging with said extended vertical Walls.

3. In a blank for origina1 sound records a spiral groove having angular ridges at its respective sides, said ridges comprising vertical Walls coincident with the sides of the groove and angular surfaces disposed at'substantially 45 degrees to said Walls.

4. In a blank for original sound records a groove having vertically projecting lips at its respective sides, said lips having angular edges whose surfaces are disposed at sub4 stantially 45 degrees.

In testimony whereof I have hereunto set my hand.

VICTOR H. EMERSON.

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