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Publication numberUS1183802 A
Publication typeGrant
Publication dateMay 16, 1916
Filing dateDec 31, 1908
Priority dateDec 31, 1908
Publication numberUS 1183802 A, US 1183802A, US-A-1183802, US1183802 A, US1183802A
InventorsLee De Forest
Original AssigneeRadio Telephone & Telegraph Company
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 1183802 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)



- APPLICATION FILED DEC. 31, 1908. 1,183,802. Patented May16,1916.


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APPLICATION FILED DEC-31,1908. 1,183,802. Patented May 16,1916.




Specification of Letters Patent.

Application filed December 81, 1908. 7 Serial N 0. 470,279.

To all whom it may concern Be it known that I, LEE DE FoREsT, a citizen of the -United States, residing in the A further object of the invention is toprovide means for emitting successive signals ofvarying characteristics. A further object is to provide means for emitting successive audible signals and varying characteristics thereof to correspond to the distances apart of the objects or stations using the apparatus.

Other objects of the invention will appear more fully hereinafter.

The invention consists substantially in the construction, combination, location and rel ative arrangement all as will be more fully hereinafter set' forth, as shown in the accompanyingdrawings, and finally pointed out in the appended claims.

Referring to the accompanying drawings,

and to the various views and reference signs appearing thereon Figure 1 is a view, somewhat diagrammatic, showing one arrangement of the range teller apparatus, embodying the principles of my invention and designed to emit successive musical notes. Fig. 2 is a view similar to .Fig. 1 showing the application of my invention to the emission of signal bell sounds. Fig. 3 isa view similar to Fig. 1 showing the application of my invention to signals emitted from a graphophone. Fig. 4 is a view similar to Fig. 1 showing the application of my invention to the operation of electrical horns.

In carrying out my invention I propose to send out a series of successive signals of varying characteristics. The signals may be sent out by sound or electro-magnet1c waves, that is, they may be audible, as, for

instance by means of bells, horns, graphophone or other sound producing means, and detected directly by the car at the receiving point, or the sound waves produced by the slgnals may be employed to vary the characteristlcs of electro-magnetic radiations, and these radiations received and detected by means of suitable apparatus at the receiving point, or the signals may be produced wholly by electrical oscillations and transmitted byelectro-radiant energy and received and detected at the receiving point by suitably arranged recelvlng apparatus, such as is ordinarily'employed to receive and detect elec:

tro-magnetic wave trains. In any case the signals of the series are so relatively arranged. and varied in the characteristics thereof as to be heard or detected at predetermined distances from the transmitting stationor point, such distances varying ac cording to .the variations in the signal char- I acteristics.

My invention maybe embodied in aiwide variety of apparatus. I have shown, and

will now describe various forms of embodimentof the principles thereof.

In one form I propose to utilize the transmission of electro-magnetic wave trains, and to interrupt the same in such manner as to produce successive audible musical notes capable of bein detected and heard at various relative pre etermined distances, and, to this end, I vary the sound characteristics of the notes, as, for instance, by varying-the pitch and intensities thereof.

In Fig. 1, I have shown anarrangement wherein I make practical application of the principles of my invention. In this fi re A designates an antenna, with the circuit of which is associated, in any well known way an oscillation circuit containing a condenser C, and an oscillator O, and fed from any suitable source of current, as, for instance, the generator G, whereby continuous oscillations of substantially constant amplitude are generated and impressed on the antenna, and electromagnetic waves of similar characteristics are radiated from the antenna in a well understood manner. The antenna circuit is connected to ground at E, through a switch S, and an adjustable resistance R, and included in this circuit is any desired current indicating device, such for instance as an ammeter D, which may be of the hot-wire type. I provide a series of branch circuits connecting the antenna to ground through the adjustable master resistance R and I arrange an interrupter 110 v Patented May 16, 1916.

i and an adjustable resistance as well as a circuit breaker, in each branch circuit, the circuit breaker being designed to complete the antenna circuit to ground successively through the various branch circuitsk This circuit breaker may be of any suitable con struction adapted to accomplish this result. I have shown it in the form of. a rotating cylinder F, carrying a series of conducting segments 7, arranged side by side and so relatively displaced rotarially as to enable the brushes 7, to successively complete their respective circuits therethrough. The adjustable resistances R}, R R R are respectively arranged in the branch circuitsand are so adjusted relative to'each other as A to introduce into'these circuits the desired relative circuit conditions to accomplish my objects and purposes. The interrupters arranged in the antenna branch earth connections above referred to may be of any desired construction and form to effect the desired relative antennacircuit interruptions to produce predetermined musical notes. In the form shown I employ commutators H with which coiiperate the brushes k, and subdivided into the desired relative number of segments. Forinstance these commutators may be provided with the required number of segments to effect the interruptions per second necessary to produce oscillatory vibrations corresponding respectively to middle C, E, G, and C of the musical scale. It is obvious, however, that any other notes of the scale may be selected by suitably varying the number of interruptions per second of the branch circuits. Thus it will be seen that the function of the commutators H is to introduce interruptions in the several branch circuits of the antenna system according to the desired notes or sounds to be produced. The function of the commutator F, is to successively connect these various branch circuits of the antenna system to earth. The switch S enables the range teller apparatus'to be short circuited or cutout when it is desired to employ the antenna system for other purposes. The master resistance R is common to all the branch circuits, and, being adjustable, serves to control the intensity of all the notes or sounds transmitt ed from the apparatus. By suitably regulating and relatively adjusting the re sistanc es R R R R the intensity of the various notes emitted may-be reduced or vathe bell circuits.

at a station say four miles away. Similarly the other resistances R R R are so adjusted that the oscillations respectively controlled by their circuits will be heard and reproduced in the receiver when three, two and one mile away respectively. These various adjustments as to distances are made, of course, with reference to the particular Wireless equipment of the sending and receiving stations or systems in connection with which the apparatus is used. i

The commutators and F may be operated in any suitable manner to accomplish their respective functions. I have shown a motor M, for operating these commutators. lVhile I have shown four branch circuits, capable of producing four notes, it is obvious that my invention is not to be limited thereof, as, for instance, in their pitch, and

at the same time the intensities of the notes are so relatively varied that the emitted oscillations are detected at the receiving station in the form. of definite predetermined sounds and at the prearranged *respe'ctive distances away from the transmitting stalLlOIL- I The utility of apparatus equipped with the range teller embodying the principles of my invention, as above explained, will be at once perceived. A light house, for instance, equipped therewith will send out electromagnetic radiations which will be detected by a ship at sea for instance, and if the ship receives only the note corresponding to middle C, in the illustration above given, it will be known that the light house is four miles away. If both the middle C and the E notes are heard then it will be known that the distance between the ship and the light house is only three miles. If the middle C, E and G, are detected at the receiving station the distance is two miles, and if all four notes are heard then the distance away is one mile or less, and so on for any other prearrangement and adjustment.

' Any suitable or well known wireless telegraphic or wireless telephonic receiving apparatus may be employed to receive, detect or reproduce the emitted or radiated signals.

In Fig. 2 I have shown another form of apparatus embodying the principles of my invention, wherein 'I' employ a series of bells, as 1, 2, 3, 4, having relatively dift'erin pitch, and, preferably, electrically operated and, of single stroke, and all arranged to be sounded into the mouthpiece of a common microphone M. arranged in the antenna earth circuit. B, is a battery for energizing These circuits are successivcly completed to ground at E, through the common or master ad ustable resistance phone is also completed to earth through said commutator, and a corresponding branch circuit, the commutator, and the corresponding bell circuit and resistance R in which branch circuits are arranged the re sistances R R R R, which are so relatively adjusted as to perform the same functions as are performed by the adjustable resistances in the branch circuits above described with reference to the arrangements shown in Fig. 1. If desired, choke coils L,

may be included in the bell circuits, as. shown. Thus it will be seen that the com-- mutator F,.performs the double function of successively completing to earth the re- SPGCtIXQ circuits of the bellsand also, and simultaneously therewith completing the circuit of the antenna system and microphone to earth through a corresponding resistance the resistances being so relatively adjusted that the radiations from the antenna system vary according to the bells employed which, as above indicated, are'of difi'erent pitch, and these radiations are reproduced or detected at the receiving station according to the distance apart of the receiving and transmitting stations.

In Fig. 3, I have shown a series of gramophone plates, J, J, J J simultaneously operated, the associated needles and trumpets K, K, K K of which are arranged in cooperative relation with respect to corresponding microphones M, M M M each microphone being included in the earth connection of the antenna. system. The microphone circuits are completed to ground through branches containing the resistances R, R R R relativelyadjusted and arranged, as above explained with reference to Figs. 1 and 2, to accomplish the desired objects of my invention. The commutator F serves to. successively complete the microphone and antenna circuits to ground. In this arrangement the motor M may serve to operate the commutator F and also the gra-mophone disks. These-- disks are prepared to reproduce phonographically the signals, which, if desired, may be in the form of sentences, denoting the relative prearranged distances to which the apparatus is adjusted. In thiscase the disks should be of suil'iciently large diameter to allow the sentences to be reproduced in a single revolution thereof, and thus be self repeating without changing the position of the needles.

In Fig. 4 I have shown my invention as applied to the operation of electrically controlled signal whistles, horns or the llke wherein the desired distance indications are transmitted wholly by sound waves. In this case I have shown a series of electrically operated reed horns 1', 2', 3. 1 respectively constructed to give out gredetermined notes, as middle C, E, G and, musical scale. The circuits of these horns are. successively completed through a common resistance R and batterylB, bymeans of a commutator F and said circuits respectively contain the adjustable resistances tances away. I v 4 It is obvious that my invention, in the broad scope thereof, as defined in the claims, may be embodied in many other different forms of apparatus.

' Having now set forth the objects and nature of my invention and various constructions embodying the principles thereof, .what I claim as new anduseful, and of my own invention 1s:

' 1. In a range indicating apparatus, an antenna system, means for generating oscillations therein, and means associated with said generating means for successively modifying such oscillations by signals varying in intensity according to predetermined ,range of transmission.

2. Ina range indicating apparatus, an

v antenna system, means for generating continuous oscillations therein, signal devices arranged to produce. signals of relatively respectively of the R, R R R so relatively adjusted'that .the notesemitted from the horns are capable of being heard at the predetermined disdifi'erent characteristics according to predetermined ranges of transmission, and each operating to modify the oscillations in the antenna system, and means for successively 1 4. In a range indicating apparatus, an

antenna system, means for generating continuous oscillations therein, means for modifying said oscillations in accordance with prearranged signals, means for relatively varying the modifying means, and means for successively closing the circuits of the modifying means to the antenna system and to ground. u I 5. In a range lndlcating apparatus, an an- ,tenna system, means for generating oscillations therein, said antenna system having a plurality of branch paths to ground, means associated with each branch path for modifying the oscillations in the antenna system, and means for intermittently closing said branch paths to ground in succession.

6. In a range indicating apparatus, an antenna system, means for generating oscillations therein, said antenna. system having a plurality of branch paths to ground,'means associated with each branch path for modifying the oscillations in the antenna sys -tem, a master resistance common to all of said ground paths, and means for intermittently closing said ground paths in success1on.

7. In a range indicating apparatus, an antenna system, means for generating oscillations therein, said antenna system having a plurality of branch circuits to ground, means associated With each branch circuit for modifying the oscillations in the antenna system, an adjustable resistance in each branch circuit, and means for intermittently closing said branch circuits in succession.

8. In a range indicating apparatus, an antenna system, means for generating oscillations therein, said antenna system having a plurality of branch circuits, means associated with each branch circuit for modifying the oscillations in the antenna system,

:an adjustable resistance in each'branch cirsaid means operating to vary said oscillations in accordance with pre-arranged signals, and means for intermittently closing said branch circuits to ground in succession.

In testimony whereof I have hereunto set my hand, in the presence of the subscribing Witnesses, on this th day of December, A. D., 1908.


Witnesses J. CLEIN, S. E. DARBY,.

Referenced by
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US2817082 *Jun 4, 1954Dec 17, 1957IttContinuous wave beacon system
US6963301Jan 31, 2003Nov 8, 2005G-Track CorporationSystem and method for near-field electromagnetic ranging
US7298314Oct 4, 2004Nov 20, 2007Q-Track CorporationNear field electromagnetic positioning system and method
US7307595Nov 10, 2005Dec 11, 2007Q-Track CorporationNear field location system and method
US7414571Aug 30, 2005Aug 19, 2008Q-Track CorporationLow frequency asset tag tracking system and method
US7952363 *Apr 25, 2008May 31, 2011Comsonics, Inc.System and method for sorting detection of signal egress from a wired communication system
US8018383Jun 8, 2010Sep 13, 2011Q-Track CorporationMethod and apparatus for determining location using signals-of-opportunity
US8599011Feb 4, 2011Dec 3, 2013Q-Track CorporationFirefighter location and rescue equipment employing path comparison of mobile tags
WO2004017087A2 *Jul 30, 2003Feb 26, 2004Q Track CorpSystem and method for near-field electromagnetic ranging
U.S. Classification342/350, 342/458, 455/355
Cooperative ClassificationH01Q25/02