United Wireless Telegraph Co. v. National Electric Signaling Co.

198 F. 386, 117 C.C.A. 262, 1912 U.S. App. LEXIS 1647
Court of Appeals for the First Circuit·Decided June 18, 1912·No. No. 953·Published·Cited by 5 cases

Opinion

BROWN, District Judge.

This is an appeal from the decree of the Circuit Court in a suit for infringement of letters patent 706,736 to Reginald A. Fessenden for apparatus for wireless telegraphy.

The appellant was found to infringe claims 6, 9, 10, 11, 12, 14, 19, 20, 21, 27, 28, 29, 30, 32, 33, and 35.

The nature of the Fessenden invention is thus set forth in the specification:

“The invention described herein relates to certain improvements in apparatus for the electrical transmission of signals- from one station to another without the use of conductors connecting such stations, such apparatus being more especially designed for the carrying out of method described and claimed in application serial No. 740,429, filed December 15, 1899.
“In the methods heretofore employed the electromagnetic waves g-enerated at the receiving-station produce voltages in the receiving-circuit. These voltages or currents, being impressed upon a suitable material normally non-conduetive, render the same conductive, and thereby permit the passage of a current through a circuit in which said material, usually termed a ‘coherer,’ is included. After the passage of the voltages produced by each series of electromagnetic waves generated at the sending station, the coherer must be operated in some way to restore it to normal or nonconductive condition.
“The object of the present invention is to provide for the generation, by currents produced by electromagnetic waves, of induced currents in a second element or circuit, and by the reaction of the current in this second element or circuit on the field formed or produced by the currents in the receiving conductor to produce motion which is directly or indirectly observable.
“In general terms the invention consists in apparatus whereby the energy of electric currents produced by electromagnetic waves may be transformed into the energy of motion and the energy of such motion employed for producing intelligible signals.”

Two of the forms of apparatus at the receiving station are thus described:

The first for producing visible movements or signals:

“At the receiving-station the receiving-conductor is conveniently formed by a wire or wires 6, projecting- up vertically or at an inclination to a suitable height, which are also grounded. A coil or coils 7 are arranged in the circuit of the conductor 6, and an element or coil of wire 8, forming a closed circuit, is supported with a freedom of movement in such relation to the coil or coils 7 that the current produced by the electromagnetic waves will induce a current in the element 8. The element 8 is suspended, preferably, in such manner that a plane at right angles to its axis will form an angle of approximately forty-five degrees (45°) with a plane at right angles to the axis of the coil or coils 7, so that the reaction of the current induced in said element, with the field produced by the coil or coils 7, will cause the element 8 to move with reference to the coils 7. This motion of the element may be observable by means of a mirror .9, attached thereto, reflecting a beam of light on a scale, or said element may form a part of the circuit of a recording siphon, etc. As shown in B'ig. 2, the coil 7 may be connected to the secondary coil 11 of a transformer, whose primary coil 12 is connected in series with the receiving-conductor.”

[388]*388The second for producing audible signals through the use of a telephone as a recording instrument:

“A desirable means for transforming tbe electromagnetic waves into recordable motion is shown in Figs. 3 and 4. Tbe element 8 is balanced on supporting-rods or knife-edges 13, one of wbieb is formed of a good electrical conductor, as silver, tbe element 8 being preferably formed by a silver ring. A carbon block 14 is so arranged that a portion of tbe ring between tbe supporting-rods will normally rest lightly thereon. This mierophonic contact, tbe conducting pivotal support, and tbe portion of tbe ring between them form parts of an electric circuit, which also includes a generator 15 and a recording instrument 16, as a telegraphic sounder or tbe receiver of a telephone. When a current is produced, as above described, in the coil 7, tbe element or ring 8 will be caused to press on the carbon block, thereby increasing its conductivity. When using a telephone-receiver as a recording instrument, the generator 15 is preferably of a character capable of producing an alternating current, as such current causes a constant vibration of the diaphragm, the vibrations increasing in intensity with an increased flow of current in the circuit.
■ “This increase in intensity of action with increased flow of current is characteristic of this form of receiver and also of the form shown in Fig. 1. In this it is sharply differentiated from such devices as the coherer, which either give a strong indication or do not give any. This characteristic is advantageous in that if the signal sent — say a dot — be too weak to give an action of the full intensity it may still in most cases be read and not missed entirely, which is of value in sending code messages.”

The features common to both forms of complainant’s apparatus are the free grounded antenna wire to act as a receiving circuit, with a coil therein whereby a field is created, and the closed ring 8 so placed that oscillating currents are induced therein, and that such induced currents will react upon the field.

In the first form ring 8 acts as the indicator.

In the second form ring 8 is used to vary the resistance of a battery circuit containing a telephone.

Each form of apparatus is operative, but neither form has been used commercially.

It is desirable at this point to describe the defendant’s apparatus in respect to such features as are here involved.

There is a free grounded antenna circuit, and an induction circuit. The induction circuit, however, differs from Fessenden’s both in structure and in the mode of utilizing the currents.

.There is in this circuit a perfectly passive piece of material, carborundum, which suffers no change of resistance or physical character like the coherer, and is a detector which will operate to give good signals, even though no local battery is used, showing that its valve action is such as to enable the incoming energy of the radiation itself to be the source of the signal.

The induction circuit with this carborundum detector has the characteristic of rectifying oscillating current, which by itself will not operate a telephone, into a series of direct impulses which will operate a telephone.

It receives electrical energy in such form that it is incapable of operating a telephone, and passes out electrical energy that will operate a telephone.

[389]*389The detector interposed in the induction circuit is also in a local battery circuit which includ.es the telephone receiver.

The battery current, a direct current, is varied by direct impulses coming through the detector; these impulses, however, being in themselves sufficient to operate the telephone.

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United Wireless Telegraph Co. v. National Electric Signaling Co., 198 F. 386, 117 C.C.A. 262, 1912 U.S. App. LEXIS 1647 (1st Cir. 1912).

198 F. 386 (United Wireless Telegraph Co. v. National Electric Signaling Co.) — published by Counsel Stack Legal Research, free access to 12M+ legal documents.

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