US203014A - edison - Google Patents

Description

2 Sheets-Sheet1. T. A. EDISON. Speaking-Telegraph. No. 203,014. Patented April 30, 1878.

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2 Sheets-Sheet 2.

T. A. EDISON. Speaking-Telegraph. No. 203,014. Patented April 30,1878.

/waufai w Imam I 8 UNITED STATES THOMAS A. EP'QON, OF MENLO PARK,

PATENT ()FFICE.

NEW JERSEY, iissienon TO wnsrnnx UNION TELEGRAPH COMPANY, OF NEIV YORK, N. Y.

IMPROVEMENT IN SPEAKlNG-T'ELEGRAPHS.

Specification forming part of Letters Patent No. 203,014, dated April 30, 1578; application filed July 20, 1877.

'10 all whom it may concern:

Be it known that I, THOMAS A. EDISON, of Menlo Park, in the county of Middlcsex and State of New Jersey, have inventedau 1m.- provement in Speaking-'Telegraphs, of which .the following is a specification:

I make use of :a resonant case with several tympans, adjusted to difl'crent degrees of tension or delicacy, and theseare all so connected with contact-points in the metallic line-circuit that the electric pulsations will be sent over the line from one or more of these tympans, and operate upon an electro-magnet and receiving-tympan of a resonator. By this arrangement it is sought to produce such undulationsof the electric currents passing over the line that they will represent the inflections of the human voice speaking into the transmit-. ting-resonator, and therefore the receiving-imstrument will be correspondingly influenced.

In the drawings, Figure 1 is a plan view,partially in section; and Fig. 2 is an end view .of

one tympan and circuit-closing device.

Thebox a is of a suitable size and shape.

At one side thereof there is a mouth-piece, b,

adapted to receiving the sounds of the human voice as spoken into the resonant box a. Thismouth-piece may be upon the topof the box, or at one of the sides thereof. It is preferable that the hollow resonant box be cubical, in order that at its sides may be placed the tympans aforesaid. I have shown four such tympans.- Each tympan is .madesimilar to the head'of akettle-drum, but preferably of a plate of metal, and it covers an opening in one of the sides of the resonant box. The edge of the tympan e is etween the rings k, and rests against the end of the cylinder h,- and there are screws f,by. which to adjust the rings and apply greater or less strain to the tympan. The tympans are all connected with the metallic line-circuit L, and in front of each there are one or more circuit-closing springs, i, preferably with carbon or plumbago points, and each spring is adjusted by the screw o, s o that the point is in nearer or more remote proximity to the tympan. The springs t are all in theci'rcuitt to the battery M B, and there is a ground-connection at G, and a shunt from the main line 'L to G, in which is placed a rheostat, R, and magnet-helix M,to neutralize the static charge and discharge. t

It will now be evident that whenever the tympans, or any one of the1n,are vibrated by the action of the voice,the linecircuit will be connected to the-battery, and pulsations sent that represent the vibrations of the tympan. I therefore construct or adjust the tympans so that'they respond to different tones or modulations of the voice, in order that when a person speaks into the resonant box the sound will beresponded to by one or more of the tympans,

and pulsations will be sent upon the line (so efficiently, so that the various modulations and tones of the voice will be represented by the electric pulsations,which, acting upon an elec- I troqnagnet at the receiving-station, will influence the resonant receiver and produce the same tones, whereby the articulation will be apparent to a listener.

011 very long lines, owing to the excessive weakness of sound in uttering the hissing consonants, the electric pulsations resulting therefrom at a certain distance cease to be perceptible. To overcome this, I arrange thedevice shown in Figs. 2 and 3 in place of one of the tympans, so as to increase the strength of the consonant waves, as in ch, S, '1, I. This is accomplished by using a plate, 0, with a small hole or slot near the center, in front of which is stretched a strip or piece ofshcct-rubberm,that

is secured near each edge of the disk 0, and laps a little over the hole in c; and upon the rubber is secured a small piece oi'platina-foil, u, an arm of which runs over to and makes connection with the plate 0. immediately opposite is a platina contactscrcw, in, which is connected to the battery through a resistance, R; and by regulating this, the hissing parts ofspeech may be increased or decreased instead of being lost, as in the other tympans, owing to the minute amplitude given them by these sounds, and also to. the enormous resistance of the plumbago points to the slight pressure which these vibrations give. By using a platina point these vibrations are rendered very loud, and by the employment of the rubber in front oil .the aperture in a great amplitude is obtained,

evento the iaintest hiss. V V I do not herein make any claim to the transmiion ol'electriccurrents varying in intensi- 1 2. The plate 0, provided with an aperture, 1 proportionately to the stmml-vihrations, as I an elasticmembrane,and circuit-breaking conthat i.\ set forth in applications heretofore tiled nections, arranged and operated substantially by me; and in my application No. 141, plum- I for and in the manner set; forth.

hago is described as acted upon by the \'ihra- Signed by me this 16th day of July, A. I). tions of the diaphragm. I (to not, therefore, T877.

elaim the same herein.

1 claim asanyinventi0n THOS. ED SON. 1. The eomhination, in the telegraphic eir- ('llilS 0f two m' more tympans, a resonant box, \\'itnesses:

and one or more circuit-(losers to eaeh t \'m- (H10. '1. PINFKNI'IY, pan. substantially as set forth. I HAROLD SI'IRRHLL.

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