US288786A - field - Google Patents

Description

(No Model.) 3 Sheets-Sheet 1.

s. D. FIELD. DYNAMO MULTIPLE TELEGRAPH.

No. 288,786. Patented Nov'. 20, 1888.

I JJVVEWTCR W21)? M By M vfl ttorneys Stepken D'Field! t e e h S S t e e h S 3. D L E T1 F D S H e d o .M o m DYNAMO MULTIPLE TELEGRAPH.

No. 288,786. Patented Nov. 20", 1883.

By his .[lttrmneys IV'ITN'ESSES' directions, simultaneously.

.connections.

NITED- STATES .ATENT rricE.

DYNANIO MULTIPLE TELEGRAPH.

SPECIFICATION forming part of Letters Patent No. 288,786, dated November 20, 1883.

Application filed August 29, 188i.

To all whom it may concern.-

Be it known that I, STEPHEN D. FIELD, a citizen of the United States, and a resident in the city, county, and State of New York, have invented certain new and useful Improvements in the Method of and Apparatus for Multiple Telegraphy, of which the following is a specification.

My invention relates to the construction and organization of apparatus employed for transmitting several communications telegraphicallyover a single conductor, in either or both Heretofore it has been customary, in organizing apparatus for multiple telegraphy, to provide at each station transmitting-keys for sending to the main line currents of different char acters, the character of each current being dependent upon the particular key, or combination of keys, which may at any time be employed, and to so include in the circuit of the main line receivinginstruments adapted to respond to the currents coming from the distant station, that each cur-rent having traversed an y or all of theinstruments will reach the earth by way of the transmitting-keys and the battery- To insure the successful operation of the receiw ing-instruments in response to their respective currents, it is essential that the comparative resistances of the different branch circuits, which the incoming currents are compelled at diiferent times to traverse, be accurately adjusted or equated, and that the balance of the line be at all times correctly maintained. Owing to the several facts that the path by which an incoming current reaches the earth changes in accordance with the relative positions of the respective keysat the receivingstation, that more or less batterypower and consequent resistance is included in the earth-circuit according to these positions, and that the contact-points of the keys forming a portion of the earth-circuit at any given moment offer more or less resistance according as they chance to form poor or good connections, it is found exceedingly difficult to maintain the balance of the line with suffi- 'cient accuracy to render such systems practically successful.

The object of my invention is to provide means for sending to the line. currents or im- (Xo model.)

pulses of any required character, and at the same time to provide for the incoming currents a ground-connection of constant resistance, whereby currents from the receiving-instruments may reach the earth independently of the transmitting devices.

My invention consists in placing an armature adapted to be rotated at any required velocity within the field of force of one or more solenoids electricallyindependent thereof, but capable of being traversed by currents, impulses, or undulations of electricity of determinate strength and polarity, thereby creatin g a field of magnetic force through or within which the armature moves. Corresponding currents, impulses, or undulations will thereby be generated in the coils of the armature, which currents are transmitted to the line by means of suitable commutators.

It also consists in combining with the transmitting apparatus suitable receiving-instruments adapted to respond, respectively, to different classes of currents transmitted from the opposite terminal of the line, and in providing an electrical connection between the re ceiving-instruments and the earth by way of the com mutators of the armature, one of which is arranged to receive currents of one polarity and is connected with the line-wire, while the other is arranged for receiving currents of the opposite polarity and is connected with the earth.

There are several methods of applying my invention to multiple teleg "aphy, all dependout, however, upon the same general principle of generating the currents to be transmitted uponthe main line in the coils of an armature in response to and in correspondence with the field of force created by the trans-.' mission of electric currents through solenoids located in the vicinity of the armature, and of providing for the incoming currents an earthconnection which is independent of the transmitting devices and circuits.

Of the accompanying drawings, illustrating the general method of carrying out'my inven tion, Figure 1 is a diagram showing its application to seXtupleX telegraphy, and Figs. 2 and 3 to two different systems of quadrnplex telegraphy.

. Referring to Fig. 1, L represents a main line rhythmical pulsations.

uniting two telegraphic stations, which, for convenience, will be hereinafter termed stationI and station II. At station I, Ihave shown three independent keys or transmitting devices, two of which are adapted to send currents of determinate strength and polarity through corresponding local circuits, constituting solenoids about a rotating armature. The remaining key acts to produce rhythmical electrical pulsations or variations in its local circuit or solenoid. At station II, I have shown three receiving-instruments adapted to respond, respectively, to currents of a given strength without reference to their p0- larity, currents of a given polarity, and

The method of transmitting the currents or impulses of the several classes will be more particularly described with reference to the construction of the apparatus itself. The receiving apparatus R at station I, I have indicated merely, deeming it unnecessary to illustrate it in full, as it is in effect the same as that shown at station II.

Considering first the transmitting apparatus, A represents an armature having the same general characteristics as the armatures commonly employed in dynamo-electric generators. In this instance it is one of the type known as the Gramme ring, and consisting of coils of insulated wire a,-wound upon a soft-iron ring, a, in a manner well understood. constructed to be rotated by means of suitable motor power and connections. (Not shown.)

Two commutator-brushesorsystems of brushes, 1 Y b and b, rest against the surface of the commutator B, which is of the usual construction The brushes 1; and b are so arranged with reference a to. the commutator-sections that cur-rents off one polarity generated within the coils of the armature will be received upon the brush b 1 and transmitted to the line L,with which it is connected, while currents of the opposite polarity will be received upon the brush 1) and Gontrary to the method adopted in dynamo-elecf tric machines, however, no portion of the currents generated in the coils of the armature is employed for intensifying the field of mag- 1 and revolves with the armature A.

reach the earth at E through the wire I.

netic force; but the latter is entirely dependent upon the passage of currents from three:

local batteries, 0 0 0, through the coils of wire constituting three solenoids, c o a", re-

. spectively included in the circuits of the three batteries, and enveloping three sections of the armature, but electrically independent thereof.

The batteries 0 and 0* are of different electromotive forces, the battery 0 having preferably about one-half as many .cells as the battery 0 and they are so included in their respective circuits that currents of opposite polarities may be caused to traverse the corresponding solenoids, c and 0 in the same or corresponding directions by closing their respective transmitting-keys K and K Thus, when It is rived from a battery having an electro-motive force of, say, ten volts will traverse the solenoid c in the direction indicated by the arrow, and when the key K is closed a negative current, derived from an electro-motive force of twenty volts, will traverse the solenoid c in the same direction. The effect of the transmission of such currents will be to cause currents of proportionate strength to be generated in the coils of the armature A, if it be revolved through or within the magnetic field thus created. When the key K alone is closed, a series of impulses of alternating polarity will be generated in the coils at, having a strength dependent upon the field of force occasioned by the passage of the current from the bat- .tery 0 through the solenoid c, and these impulses will be collected with respect to their polarity by the commutator-brushes b and b in a manner well understood. A continuous current or impulse of a given polarity say positivewill thus be transmitted over the line L from the brush 7), the duration of which will depend upon the duration of the current traversing the solenoid. For convenience, this resultant current will be hereinafter referred to as due to an electro-motive force of ten volts. \Vhen the key K alone is depressed, a current or impulse of a strength dependent upon the field of force created by the flow of a current from the battery 0 through the solenoid a, but having the opposite polarity from that occasioned by closing the key K, will be transmitted to the line. This current may be considered as a negative current due to an electro-motive force of twenty volts. NVhen both keys are simultaneously closed, the current sent to line will have a strength proportionate to the field of force occasioned by the combined-effects of the batteries 0 and o that is to say, the current caused to traverse the main line will be a negative current due to an electro-motive force of ten volts. The current thus transmitted may be considered a negative current. In this manner currents of three different strengths may be transmitted upon the main line through the instrumentality of the keys K and K and these currents may be employed for actuating two different receiving-instruments at station II, in a manner hereinafter minate rate, depending upon its construction.

It is provided with a contact-spring, g, which is included, together with the electro-magnet F, in the circuit of the battery 0, which bat- 'sioned bythe depression of the keys K, K,

tery is preferably of comparatively small electro motive force-for example, three volts. This instrument constitutes an automatic interrupter, and when the circuit of the battery 0' is closed by the depression of the transmitting-key K the reedarmature will be thrown into vibration, the rate of which will depend upon the pitch or note to which it is tuned. So long as the key K remains depressed, this vibration will continue and the circuit of the battery 0 will be broken at each vibration, thus establishing in the solenoid c an intermittent or pulsatory current, the polarity and direction of which are preferably the same as those of the current caused by the depression of the key K to traverse the solenoid 0 The current generated in the coils a of the armature A, in response to the pulsatory currents in the solenoid a, will, it is evident, itself be pulsatory, and this current will be sent to line in the same manner as alreadydescribed with reference to the keys K and K When either or both keys K and K are depressed simultaneously with the key K, the effect of the pulsatory current will be to cause variations in the strength of the current transmitted upon the main line, without materially affecting its total strength. The effect, however, upon the receiving-instrument at station 11, corresponding to the key K will be the same as when that key alone is depressed.

Referring now to the receiving apparatus at station II, three instruments, R R R, are provided, which instruments are adapted to respond, respectively, to the currents occaand K, whether those keys be depressed one at a time or two or more simultaneously. To effect this result I provide the electro-magnet m of the receiving-instrument R with a yielding contact lever, r, which carries a stop against which the main armature-lever,r, plays in lieu of the usual fixed stop. This contactlever r is normally held by a spring, t, against a fixed stop, 8, and the local circuit of a bat tery, p, which includes a sounder, S, is' made 5 will be sufficient to cause the armature-lever r to come in contact with the contact-lever 1*, but it will be insuiiicient to overcome the tension of the retraetile spring t. A circuit will therefore be closed through the sounder S un- 'der the influence of such a current. A current due to an electromotive force of twenty volts, however, will be sufficient to overcome the tension of the retractile springs 23 and t and interrupt-the local circuit by breaking the. circuit betweenthe contactlever r and The sounder S of the receivingthe stop 8.

instrument R will therefore respond to those currents only which are transmitted while the key K is depressed. The receivinginstru Inent R for responding to the movements of the key K consists of an electro-magnet, m provided with a polarized armature, r", adapted to be thrown, under the influence of cur rents of negative polarity and due to an electro-motive force of ten volts or more, against a contact-stop, 8 thereby closing the circuit of a local battery, 1), and actuating the sounder S The receiving-instrument R adapted to respond to the rhythmical vibrations produced by the transmitter K consists of an electro magnet, an, provided with a reed armature, 9", tuned to the same pitch as the transmitting-reed, and capable, therefore, of responding only to electrical vibrations or undulations having the same frequency or fundamental pitch as those occasioned by the transmitter K. A local battery, includes in its circuit a suitable instrument, S, actuated by and in correspondence with the contacts of the reed g with the contact-point s", occasioned by the movements of the armature r In this manner I am enabled to transmit over one line, by means of three different transmitting devices at station I, currents of different characters which will be received and responded to by one, two, or three instruments at station II.

For the purpose of transmitting messages simultaneouslyin opposite directions overthe same wire, the apparatus above described may be combined with any suitable system of duplexing of well-known construction.

In Fig. 2 I have illustrated a method of applying my invention to quadruplex telegraphy, which consists in employing one solenoid only for creating the magnetic field for the armatnre FA, and in organizing the transmitting apparatus either for varying the strength of the current which normally traverses the solenoid, or for reversing its polarity. The means which I employ for this purpose consist of two transmitting-keys, K and K one of which, K", is a pole-changing key adapted to reverse the poles of the battery 0, with reference to their connections with the terminals of the solenoid 0*, while the other key, K is arranged to throw in or out of circuit a portion of the main battery. For this purpose I prefer to construct the main battery 0 in two sections, 0 and 0 the section 0 having preferably an electro-motive force of about five volts, while that of the section 0 is ten volts. The key K consists of an arm, k, constituting the key lever and extending between two supplemental levers or arms, It and k into electrical contact with either of which it may be brought.-

A resting contact-stop, s, is provided common to both supplemental levers 7c and 75-, and against which one or the other rests when not in contact with the key-lever k. The resting contact 5- is connected by a wire, 11, with one pole-in thisinstance the negative of the battery O-while the key-lever 7c is connected by the wires 5 and 6 with the opposite pole of the same battery. The supplemental levers k and k are respectively connected with the terminals 9 and 10 of the solenoid c.

The.transmitting-key K consists of a lever, k connected by the wire 6 with the positive pole of the battery-section 0 and provided with a supplemental lever, k", connected by a wire, 8, with the positive pole of the batterysection 0. The supplemental lever 75* normally rests upon a contact-point, 0, through which the two battery-sections 0 and 0 are normally connected. When the key-lever k is pressed upward against the lever the connection between the two battery-sections will be broken.

It will be understood from the foregoing that by operating the key K the electro-motive force of the battery furnishing the current which normally traverses the solenoid a will be reduced from fifteen to five volts, and by means of the key K the polarity of the current traversing the solenoid, whether it proceed from both battery-sections or the section 0 alone, may be reversed. erated in the coils a of the armature A and transmitted to line will vary accordingly. Thus normally a current will be transmitted upon the main line having a strength dependent upon the revolution of the armature at a given rate within the magnetic field created by a positive current proceeding from a battery having an electro-motive force of fifteen volts and traversing the solenoid c. If the key K alone be depressed, the polarity of this current will be reversed,while its strength remains the same. If key K alone be depressed, the current will be diminished in proportion to the diminution in the strength of the solenoid-current, and if both keys K and K be simultaneously depressed the normal current upon the main line will be diminished to the same extent as when the key K alone is depressed, and its polarity at the same time reversed. The currents of the three different characters thus generated may be caused to actuate any suitable receiving-instruments at the distant station.

In the drawings I have shown two receivinginstruments, R" and R arranged to respond to the movements of the keys K* and K, respectively. The instrument R" consists of an electro-magnet, m, included in the circuit of the main line and provided with a polarized armature, r, the magnetization of which is such as to cause it to respond to positive currents transmitted from the main line through the coil of its electro magnet by striking against the sounding-post q in opposition to the force exerted by the retractile spring it, but remaining inactive under the influence of a negative current.

The receiving-instrument R consists of an electro-magnet, m likewise included in the circuit of the main line, but provided with a The currents genneutral armature, 1-, carried upon an armature-lever, g hen resting against its back contact-stop, 8 the armature-lever g closes thecircuit of a local battery, p and actuates a sounder, S in a manner well understood.

A retractile spring, 9, is adjusted to exert a sufficient tension upon the armature-lever g to cause it to rest against its back contact-stop at other times than when it is attracted by a current of greater strength than that generated in thearmature A under the influence of an electro-motive force of five volts. The spring i will, however, yield to the magnetism produced by a current of greater strength, and of either polarity, traversing the coils of its electro-magnet, and bring the armature-lever Q5 against the front contact, thus breaking the local circuit.

The operationwill be as follows: IVhenboth keys are open, a negative current due to an electro-motive force of fifteen volts will traverse theline. The polarized armature T will be held against the resting contact-stop 25, both by, virtue of the retractile spring and the magnetism induced in the cores of its electro-magnet. The neutral armature r however, will be attracted with sufficient force to overcome the tension of the spring t and its lever will rest against its front contact, the sounder S being therefore inactive. If the key K be depressed, a positive current due to an electro-motive force of fifteen volts will traverse the main line, and the polarized armaturer will respond ac cordingly. The reversal of the polarity of the current will be too rapid, however, to allow the armature r to fall away from its electromagnet, and the sounder S will still remain inactive. If the key K alone be depressed, a negative current due to an electro-motive force of five volts will traverse the main line. This current will produce in the electro-magnet m magnetism'of the polarity which tends to repel its armature o from the soundingpost Q4, and the receiving-instrument It will therefore remain inactive. The same current, however, will be insufficient to maintain the armature r in its forward position in opposition to the force exerted by its retractile spring t and its lever will therefore fall against the back contact, 8", and cause the sounder S to be actuated. WVhen both keys K and K are simultaneously depressed, a

negative current due to an electro-motive scribed with reference to Fig. 2. The plan, however, consists in employing a battery of constant electro-motive force, and throwing in or out of circuit a greater or less portion of the solenoid surrounding the armature,instead of varying the electro-motive force of the battery. I

1n the drawings I have represented the armature A as surrounded by one solenoid, O,

composed of two sections, 0 and 0 The two sections are normally connected with each other by means of a'lever, is, resting upon a contact-stop, s A battery, 0, having an electro-motive force of, say, fifteen volts, is normally'so connected with the terminals of the solenoid O that a positive current traverses the entire solenoid in the direction indicated by the arrow. Two transmitting-keys, K and K, are provided, the former of which is of the same general construction as the key K described in connection with Fig. 2, and is arranged to reverse the poles of the battery 0 with reference to its connections with the terminals of the solenoid by connecting the positive pole of the battery through the wire 11 and key-lever 7a with the supplemental lever 2: or it, according as the key K is elevated or depressed, and thus by means of one of the wires 12 or 14 with one or the other terminal of the solenoid C Y The key K consists of a lever, k connecte by a wire, 13, with the conductor 2, leading to one terminal of the solenoid G. hen the key K is depressed, it comes in contact with the lever It, raising it from the contact-stop s and closing the circuit of the battery 0 through the wire 11, key-lever k, and contact- spring k wires 12 and 13, key-l ever If, supplemental lever k solenoid-section c, and wire 14 to the contact-spring k and stop S", and by the wire 15 to the negative pole of the battery 0, thus cutting the solenoid-section 0 out of circuit. Thus the key K serves to reverse the polarity of the battery 0, while the key K determines whether the entire solenoid or only the section 0 be included in circuit. Supposing the solenoid-sections c and o be so constituted that the induced current generated in the coils of the armature A by'its revolution through the magnetic field produced by the current from the battery 0 traversing the solenoid-section c has a strength one-thi rd as great as that generated when the current traverses both sections 0 and c then when both keys are in their normal position the current transmitted to line may be considered as a positive current due to an electromotive force of fifteen volts. When the key K is depressed, it will be a negative current of the same strength." When the key K alone is depressed, it will be a positive current of onethird the normal strength, and when both keys K and K are simultaneously depressed it will be a negative current of one-third the normal strength. In this manner, by operating the keys K and K individually and in combination, currents of the same character maybe transmitted to the main line, as described with reference to Fig. 2, and these may be employed for actuating any suit-able receiving-instruments at the distant station, preferably, however, such as described in connection with Fig. 2.

It is obvious that any suitable and wellknown system for transmitting and receiving currents in opposite directions over the same line may be combined with the devices shown in Figs. 2 and 3, as well as with that shown in Fig. 1.

I am aware that it is not new to employ induced currents for actuating the receiving-in struments of a telegraphic system, as it has been proposed to locate a magneto-electric generator at the receiving-station of such a system, and to include the coils of its fieldmagnets in the circuit of the main line, the receiving-instruments in such case being included in a local circuit with the armature of the generator. In such an organization, however, the transmitting-instruments must be located in the circuit of the main line, and the incoming impulses are thus compelled to pass through the same, whereas in my organization such currents are provided with an earth-connection which is independent of the transmitting-instruments, and is, moreover, of practically constant resistance.

I claim as my invention- 1. The combination, substantially as hereinbefore set forth, with the armature of an electric generator and one or more solenoids for establishing a field of force for said armature, of one or more excitinggenerators, independent devices for transmitting at will electric currents, impulses, or undulations from said exciting generator or generators through the conductor or conductors constituting said solenoid or solenoids, a main line, and connections, substantially such as described, for transmitting electric currents from the coils of said armature upon said main line.

2. The combination, substantially as hereinbefore set forth, with the armature of an electric generator, of a main line, means for maintaining the terminals oii said mainline in electric connection with the coils of said armature, one or more solenoids for establishing a field of force for said armature, one or more local electric generators, and means for transmitting at will determinate electric currents, impulses, or undulations through any or all of said solenoids.

3. The combination, substantially as hereinbefore set forth, with the armature of an electric generator, its commutator and commutator brushes, and means, substantially such as described, for establishing or varying the field of force of said armature, of an inde pendent main line connected with the earth through said commutator and con1mutatorwith the earth through said commutatorbrushes, and one or more telegraphic receivbrushes, and receiving-instruments included ing-instruments included in said main line. in said main line.

4. The combination, substantially as here- In testimony whereof I have hereunto sub- 5 inbefore set forth, With the armature of an scribed myname this24th day of August, A. D. I 5

electric generator, its commutator and com- 1882. mutator-brushes, and transmitting devices for STEPHEN D. FIELD. controlling the field of force created by electric WVitnesses: currents traversing the solenoids of said gen- DANIEL W. EDGEOOMB,

IO erator, of an independent main line connected CHARLES A. TERRY.

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