Range-teller.

Application filed December 31,1908. Serial No. 470,279.

To dll whom it may concern :

Be it known that I, Lee de Forest, a citizen of the United States, residing in the city, county, and State of New York, have 5 made a certain new and useful Invention in Range-Tellers, of which the following is a specification.

This invention relates to signal apparatus for disclosing the distance apart of two ob10 jects, such, for instance, as two ships, a ship and a shore station, light house or the like, or of trains, or other objects.

The object of the invention is to provide a signal apparatus which is simple and effi15 cient for disclosing audibly or otherwise the distance apart of two objects.

A further object of the invention is to provide means for emitting successive signals of varying 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 relative arrangement all as will be more fully 30 hereinafter set forth, as shown in the accompanying drawings, and finally pointed out in the appended claims.

Referring to the accompanying drawings, and to the various views and reference signs 35 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 is a view similar to Fig. 1 showing the application of my invention to signals emitted from a grapho45 phone. 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 50 varying characteristics. The signals may be sent out by sound or electro-magnetic waves, that is, they may be audible, as, for instance by means of bells, horns, graphophone or other sound producing means, and 55 detected directly by the ear at the receiving point, or the sound waves produced by the signals may be employed to vary the characteristics of electro-magnetic radiations, and these radiations received and detected by means of suitable apparatus at the receiving 60 point, or the signals may be produced wholly by electrical oscillations and transmitted by electro-radiant energy and received and detected at the receiving point by suitably arranged receiving apparatus, such as is ordi- 65 narily 'employed to receive and detect electro-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 prede- 70 termined distances from the transmitting station or point, such distances varying according to the variations in the signal char- acteristics.

My invention may be embodied in a wide 75 variety of apparatus. I have shown, and will now describe various forms of embodiment . of the principles thereof.

In one form I propose to utilize the transmission of electro-magnetic wave trains, and 80 to interrupt the same in such manner as to produce successive audible musical notes capable of being detected and heard at various relative predetermined distances, and, to this end, I vary the sound characteristics of 85 the notes, as, for instance, by varying the pitch and intensities thereof.

In Fig. 1, I have shown an. arrangement wherein I make practical application of the principles of my invention. In this figure 90 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, 95 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 100 antenna in a well understood manner. The antenna circuit is connected to ground at E, through a switch S, and an adjustable resistance R^B, and included in this circuit is any desired current indicating device, such 105 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 R⁵, and I arrange an interrupter no

1,183,802 £2 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 circuits. ·· This circuit breaker may be of any suitable construction adapted to accomplish this result. I have shown it in the form of. a rotating Cylinder F, carrying a series of conducting 10 segments /,. arranged side by side and so relatively displaced rotarially as to enable the brushes f \ to successively complete their respective circuits therethrough. The adjustable resistances R¹, R², R³j R⁴, are re-.

spectively arranged in the branch circuits and are so adjusted relative to each other as to introduce into these circuits the desired relative circuit conditions to accomplish my objects and purposes. The interrupters ar20 ranged in the antenna branch earth connections above referred to may be of any desired construction and form to effect the desired relative antehiia circuit interruptions to produce predetermined musical notes. In the form shown I employ commutators H with which cooperate the brushes A, and subdivided into the desired relative number of segments. For instance 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 35 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 40 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 cut out when it is desired to employ the antenna system for other purposes. The master resistance R⁵ is common to all the branch circuits, 50 and, being adjustable, serves to control the intensity of all the notes or sounds transmitted from the apparatus.. By suitably regulating and relatively adjusting the resistances R¹, R², R³, R⁴, the intensity of the 55 various notes emitted may be reduced or varied so as to be heard at any desired or predetermined relative distances away. Thus the resistance R¹ may be so adjusted that the oscillations produced in the interrupted 60 branch circuit in which said resistance is placed will result in radiations of electromagnetic waves from the antenna system, when said branch circuit is connected to earth, which cause the production of, say, 65 middle C, in a wireless telephone receiver at a station say four miles away. Similarly the other resistances R², R³, R⁴, are so adjusted that the oscillations respectively controlled by their circuits will be heard and reproduced in the receiver when three, two 70' 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 75 with which the apparatus is used.

The commutators H and F may be operated in any suitable manner to accomplish their respective functions. I have shown a motor M, for operating these commutators, se While I have shown four branch, circuits, capable of producing four notes, it is obvious that my invention is not to be limited or restricted in this respect.

From the foregoing description it will be ss seen that I produce successive signals which vary from each other in the characteristics thereof, as, for instance, in their pitch, and at the same time the intensities of the notes are so relatively varied that the emitted 90 oscillations are detected at the receiving station in the form of definite predetermined sounds and at the prearranged .‘respective distances away from the transmitting station. . . ⁹⁵

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 electro- ιοί magnetic 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 10! 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 sta- ID tion the distance is tivo miles, and if all four notes are heard then the distance away is one mile or less, and so on for any other piearrangement and adjustment.

Any suitable or well known wireless tele- 11 graphic 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 1 2 invention, -wherein I employ a series ot bells, as 1, 2, 3, 4, having relatively differing pitch, and, preferably, electrically operateci and of single stroke, and all arranged to be sounded into the mouthpiece of a common 12 microphone M^z. arranged in the antenna earth circuit. Β, is a battery for energizing the bell circuits. These circuits are successively completed to ground at E, through the common or master adjustable resistance 13

1,183,802

R⁵, by means of the commutator F'. Simultaneously with the completion of each bell circuit to ground through the commutator F', the circuit of the antenna and the micro3 phone is also completed to earth through said commutator, and a corresponding branch circuit, the commutator, and the corresponding bell circuit and resistance R^B in which branch circuits are arranged the re; io sistances R¹, R², R³, R⁴, 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 15 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 commutator F',. performs the double function of successively completing to earth the re20 spective circuits of the bells and also, and simultaneously therewith completing. the circuit of the antenna system and microphone to earth through a corresponding resistance the resistances being so relatively 25 adjusted that the radiations from the antenna system vary according to the bells employed which, as above indicated, are of different pitch, and these radiations are reproduced or detected at the receiving station 30 according to the distance apart of the receiving and transmitting stations.

In Fig. 3,1 have shown a series of gramophone plates, J, J', J², J³, simultaneously operated, the associated needles and trum35 pets K, K', K², K³, of which are arranged in cooperative relation with respect to corresponding microphones Μ', Μ², Μ³, M⁴, each microphone being included in the earth connection of the antenna system. The micro40 phone circuits are completed to ground through branches containing the resistances R', R^z, R³, R⁴, relatively adjusted and arranged, as above explained with reference to Figs. 1 and 2, to accomplish the desired 45 objects of my invention. The commutator F², serves to successively complete the microphone and antenna circuits to ground. In this arrangement the motor M may serve to operate the commutator F², and also the 50 gramophone 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 55 adjusted. In this case the disks should be of sufficiently 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, eo In Fig. 4 I have shown my invention as applied to the operation of electrically controlled signal whistles, horns or the like wherein the desired distance indications are transmitted wholly by sound waves. In this βδ case I have shown a series of electrically op erated reed horns 1', 2', 3' 4⁷, respectively constructed to give out predetermined notes; as middle C, E, G and C, respectively of the musical scale. The circuits of these horns are successively completed through a com- jo mon resistance R^B, and battery B', by means of a commutator F³, and said circuits respectively contain the adjustable resistances R', R², R³, R⁴, so relatively adjusted that . the notes emitted from the horns are capa- 75 ble of being heard at the predetermined distances away.

It is obvious that my invention, in the broad scope thereof, as defined in the claims, may be embodied in many other different 80 forms of apparatus.