US496513A - Vibratory telegraphy - Google Patents

Description

I (No Model.)

S. D. FIELD. VIBRATORY TBLEGRAPHY.

No. 496,513. Patented May 2, 1898.

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UNITED; STATES AT NT OFFICE.

STEPHEN n. FIELD, or YONKERS, NEW YORK.

VIBRATO RY TELEG RAPHY.

SPECIFICATION forming part of Letters Patent No. 496,513, dated May 2, 1893.

Application filed July 30, 1892.

To all whom it may concern.-

Be it known that I, STEPHEN DUDLEY FIELD, a citizen of the United States, residing at Yonkers,in the county of Westchester and State of New York, have invented certain new and useful Improvements in Vibratory Telegraphy or Telephony; and I do hereby declare the following to be a full, clear, and

exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to electric signaling, its object being to render minute electrical vibrations, including those developed in the transmission of vocal utterances, available for intercommunication between several points or stations.

The invention is carried out by maintaining a succession of rapid vibratory or undulatory electric impulses in a circuit preferably raising the tension of such impulses by means of a transformer or induction coil and varying the strength of such impulses by a transmitting apparatus in accordance with the signal to be transmitted whether vocal or otherwise.

The several features of novelty will be more particularly hereinafter described and definitely indicated in the claims appended to this specification.

In the accompanying drawing the figure shows a diagram of a system embodying my invention.

Referring first to the figure, A and B represent two distant stations and 0 an intermediate station. At station 0 are two induction coils, the secondaries of which are connected respectively with the lines extending to stations A and B, and the primaries of which are connected with a local circuit including a device for creating rapid vibrations or undulations of a local current. A preferred form of apparatus for creating these rapid vibrations is my thermic vibrator, comprising a German silver wire 1, 2, having one end mounted againsta rubber cushion 3 supported in a standard projecting from metallic frame 4, and its other end made adjust-able so that the tension may be varied. A-threaded rod 5 sliding through a standard on the frame 4 co-operating with an adjusting nut 6 forms a simple and efficient mechanism for droviping Serial No. 441,756. (No model.)

the necessary adjustment. The cushioned end of the wire carries a contact 7 against which is pendulously supported a co-operating contact 8. One of these contacts is preferably formed of carbon though both may be made of metal. A pivotally supported arm 9 and a regulating weight mounted on a rod 10 afford convenient means of varying the force of the contact at 7, 8. The primaries of the induction coils are connected in series and the free terminals are carried respectively to the contact 7 and to the frame 4 at the fixed end of the wire. Two local batteries 11, 12 are placed at the two sides of the wire, and a wire 13, flexibly connected with the wire 1, 2 at or neara central point, forms a bridge between the wire and the two primaries 15, 16.

At the stations A and B are provided suitable receiving or transmitting devices capable of responding to electrical vibrations or undulations or of throwing them upon line. They may be an ordinary magneto telephone acting as a receiver or transmitter or the usual telephonic outfit comprising a magneto re ceiver and carbon transmitter. When the apparatus is in its normal condition the batteries 11, 12 discharging over the circuit l1, 15, 16, 12, 2, 1,heat the German silver wire and cause it to expand; the shunt through contacts 7, 8 carries part of the current away from the wire over the path 9, 4, thus causing the wire to cool and contract. This state of afiairs induces an exceedingly rapid variation of contact of very high resistance at the points 7,8, the pendulous weight being unable to follow the rapid changes in the wire, causing rapid fluctuations in the primaries of induction coils 15, 16, inducing corresponding fluctuations upon the lines; but the vibrations are so exceedingly rapid as to be inaudible to the intervals when the circuit is open, and other intervals when it is closed, thus varying the resistance within extremely wide limits. XVhen the points '7, S are in firm contact, the wire 1, 2 is substantially short-eircuited and when the points 7, 8 are out of contact the wire 1, 2 must carry the entire current of both batteries. Suppose an electrical vibration proceeds from station A, it will induce in the primary of the transformer 15, at O, a vibration of low electro-motive-force which will vary the strength of the normal current circulating over the local circuit. The bridge Wire 13 permits the currents induced by the transmitting vibrations to be localized in one of the sections 1 or 20f the t-hermic wire, thus avoiding the necessity of their passage through both induction coils, which would weaken their effect by the choking action they would exert. The increased current causes an abnormal expansion of the thermic wire and creates considerable fluctuations of resistance between the contacts which reacting on the battery circuit and the induction coils relay strong impulses to station B. k

It is important that the variations of electro-motive-force normally developed by the thermic vibrator should be inaudible t0 the car, so that, unless signals or vibrations emanating at A or 13 having an audible rate 0ccupy the line, silence would exist in the receiving instrument. The pendulously supported contact 8 is well adapted to secure this result. Eeing mounted on the end of a comparatively long arm its inherent rate of vibration will be so slow that the variations of electromotive-force which such inherent vibrations impose will not interfere with perfeet transmission of the signals emanating from one of the stations. If the contact 8 were mounted upon an elastic support having an audible rate of vibration or a tone of its own, such tone would be imposed upon the line.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is i 1. An electric signaling system comprising a line wire including several signaling stations, a thermic vibrator for normally imposing rapid electrical vibrations upon said line wire, said vibrator comprising a stretched wire mounted on inharmonious supports, an electric generator normally discharging over said wire, a pendulous contact having an inaudible rate of "ibration closing a short circuit around the wire, and signal transmitting instruments at the stations for varying the force of the vibrations in accordance with the signals to be transmitted.

2. A signaling system provided with means for imposing rapid electrical Vibrations on lines connecting two or more stations, said means comprising a thermic vibrator for varying the resistance of a local circuit,including the primaries of two or more induction coils, the secondaries of which charge the line, a bridge wire connccting the thermic wire with a point between the primaries, and an electric generator on each side of said bridge wire.

In testimony whereof I affix my signature in presence of two witnesses.

STEPHEN l). FIELD. \Vitnesses:

RonT. II. READ, VIcTon E. BURKE.

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