US1819083A - Phonograph reproducer - Google Patents

Description

Aug. 18, 1931. w. H. EDWARDS 1,819,083

PHONOGRAPH REPRODUCER Filed may 14, 1929 20 f um [Illlliwl lNvE g Wwam S ATTORNEY Patented Aug. 18, 1931 Url-ED STATES.

wIELrAM'H. EDWARDS, or GREAT NECK, NEW YoEKg-Assrenon fro, AMERICAN TELE- PHONE .ann rEE-EGEAPH .eoMPAnx .aoon-poaa'rron OE `NEW YORK o PHONOGEAPH Application led May 114,l

acter tor stress will vary its impedance in the` circuit. In accordance with the arrangements of this invention, the' stress to which ation of a phonograph needle arm attached thereto. Under such' conditions, the arrangements may operate as a reproducer of sounds recorded on a phonograph record." Gther objects and features of the invention will appear more 'fully from the detailed description thereof hereinafter given.

For purposes of illustration,` it will bea-s4 sumed that the element whose impedanceis to be varied by the method of'this invention' may be a rectifier ofthe well known copper oxidetype. However, other types of thin film or Contact rectiers may be utilized. One of the suitable methods of forming the rectifier element might consist ink heating a copper sheet about .005 thick to over 1000o C. until a thin closely adherent layer of cuprous oxide about one or two thousandths of an inch is formed. A. heat treatment is then administered at lower temperatures. The outer surface of the oxide may then be reduced to metallic copper by electrolysis. The impedance element in the circuit might be formed of one or more of such units.

At the junction of the bulk of the cuprous oxide and the other copper there is believed to be a transition layer wherein the copper oxide crystals match perfectly the copper crystals which they adjoin. This transition layer is of high resistivity butin formation is made to match on to the copper in such a way (probably with considerable stress in the transition layer) as to reduce to a lowT value the work functionv of escape into it of electrons from the copper. However,

is subjected to external stress. It has been the devicel is subjected is caused by the oper- EEraoDU-OER.-

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it matches onto thel adjoining euprous oxide 1n' such va way 'as tor lmake "alarge' work function.` There is no such effect between the-thin metallic'copper on rthe outer surface of the o-Xid'e as between the mother copper and theoxide due tothe different mannerin whiehit is formed. VBased on the theoryof"` a transition layer'depending upon lnitial stresses or on substantially perfectly matched crystals, it is proposed in accordance with the principles of this invention to vary the stresses iin this transition layer or the manner in which Vthe crystals are matched and thus vary the work functions. Inasmuch as the oxide and surface coating of copper are very thin, the transition layer isn-ear the surface of the rectifier plate and is subject' to` approximately vthe maximum fibre stresses existing in the plate when it is iiexed.' Furthermore; when a portion of the plate bends in one direction, the transition layer has tensioirstresses superimposed on the initial stresses, and when bent the other.

way, has compression `stresses added tov it. It has'been'found by experiment that bending" a plate-so thatthe oxide is placed' in tension instantly increases .the resistance in the reverse direction and that when placed in compression-, the opposite occurs. It has also been found that variations .in pressure cause variations' in resistance in the conducting' direction.` Also, if kept within proper respondingstress tothedi's'k, thus bending i f it and subjecting its parts Ato tension and compression. A"This will 'vary its impedance in the circuit in accordance vwith the indentations on the phonograph record. 'Byconnecting the circuit to loud speaker appara- Similar reference characters have been uti.

lized to denote like parts in all of the figures.

In Fig. 1 is shown a circuit1in-Which is connected the stressed thin film rectifier disk 2. A phonograph needle 'arm' 3 is shown affixed to the central portionof this disk, as Will be pointed out hereinafter.r

The circuit also includes battery 4,21 switch 6, a variable resistance 5 for Ycontrolling. the current fioW and the Winding of a transformer 7. The other winding of the transformer 7 will be .included in a circuit 8 Which may lead toloud speaker apparatus.

In Fig. 3 is shown a side view of the device of the invention utilized as a phonograph reproducer. Fig. 2 is a sectional view of the arrangements of Fig. 3 along the lines A-A. Similar reference characters have been utilized to denote like parts in both figures. In these figures there is shown a base member 9, a turn-table 10 and a phonograph record 11 mounted on the turn-table.V

A swivel support 12 is provided for the reproducer arm 18 of the device. Mounted in the reproducer arm 18 is the rectifier disk 20. This disk will be surrounded at its periphery by the metallic contact rings 19, one on each side of said disk.

. contact rings Will be held in place by a soft The disk .and

`controlled .by said needle holder for subjecting said disk to stresses by bending and thereby varying the impedance of the disk. 2. An electrical phonograph reproducer 'including' a thin film rectifier disk, and

means for varying the impedance of said disk by subjecting it to bending stresses in accordance. With recorded sound.

3. An electrical phonograph reproducer including a thin film vrectifier disk, and means for varying the impedance of said diskby subjecting it to stress by bending, said means comprising a phonograph needle arm associated with said disk.

4. An electrical phonograph reproducer including a thin film rectifier disk, and means for varying the impedance of said disk by subjecting it to stress by bending, said means comprising an arm with fulcrum movement having one extremity connected to said disk and the other extremity under control of a sound record. j I 5. An electrical phonograph reproducer including a contact rectifier of the electronic variety, a sound record, and means controlled by said sound record for subjecting said rectifier to stresses by bending and thereby varying its impedance.

In testimony whereof, I have signed m name to this specification this 11th day of May, `1929. i Y

v WILLIAM H. EDVARDS.

'ill

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needle caused by the indentations on the v record Will cause the needle arm to impart to the rectier disk certain stresses. Y.In other Words, the disk will be caused to bendrin accordance With the indentations on the record. n As has been previously pointed out, this subjecting of the disk' to stresses Will vary its impedance in a circuit. The disk isY connected to a circuit by means ofthe flexible conductors 22 fastened to each of the contact rings and Vcarried through the reproducer arm to the balance of the circuit, as indicated in Fig. 1. By thus varying the impedance of the rectifier disk by means of the phonograph needle attachment, the arrangements may be utilized as a phonograph reproducer.

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