US1133923A - Telephony. - Google Patents

Description

s. G. BROWN:

TELEPHONY. v Arimunion FILED JULY 6, 1914. 1,1 33,923. Patented Mar. 30, 1915.

' v N z SHEETS-SHEET 1.

away s. G. BROWN.

7 TELEPHONY. APPLIUA'FIOH FILED JULY 6, 1914.

Patented Mar. 30, 1915;

2 SHEETS-SHEET 2.

- fivezzfo-r azdlzeg G..Brbwrt m TED STATES PATENT carton.

SIDNEY GEORGE BROWN, LONDON, ENGLAND. W

TELEPHONY.

Specification of Letters Patent. Patnted Mar, 30, 1915.

Application filed m; 6, 1914'. Serial No. 849,261.

T all whom it'may concern."

Be it known that I, SIDNEY Gnoncn BRoWN, a subject of the King of Great Britain, residing at 4 Great Winchester street, in the city and county of London, England, have invented certain new and useful Improvements in or Relating to'Telephony, ofc which the following is a specification.

This invention relatesto telephony and has reference to telephone relay systems of the kind in which the two stations between which communication is establishedare connected by way (of relay apparatus so arranged that when voice currents originating in a transmitter at one stationare sent along the line to the relay apparatus the distant receiving station is rendered incapable of operating the relay apparatus but is com nected with the source of magnified voice currents produced in'the said relay 'apparatus. In, the specification of my prior British Patent No 9179 of 1912 I have described several arrangements for operating in this manner. 1 p

- The chief ob ects of the present invention are to improve the system of working in cer- According to the present invention relay apparatus at the relay station is associated with a change-over switch adapted to be moved automatically into one or other position immediately voice currents commence to fiow from one or other of the terminal stations, thereby placing the particularstation from which the voice currents originate in permanent connection with the energizing portion of the relay apparatus, andplacing the reinforcing portion of this .ap-

paratus iii-permanent connection with the other station, until varying currents are produced by speaking at the latter stat-ion, whereupon'the electrical conditions are immediately'reversed. I

The'use of a double-pole change-over ,switch enables the relay apparatus to consist Ma single telephone relay,- thus affording simplification and economy of working, and

other reinforcing. circuit.

reducing attention on the ator to a minimum.

In order that the invention may be clearly I understood and readily carried into effect, I

will now describe the same more, fully with reference to the accompanying drawings, in

which v Figure 1 represents diagrammatically one arrangement of apparatus constituting a telephone relay system adapted to operate in accordance with the invention. Figs. 1 and l are fragmentary diagrams illustrating modifications. Fig.2 is a modification of thesystem shown in Fig. 1, and Figs. 3 and 4 are two further modifications. I'will first describe the relay system as illustrated in Fig. 1. A and B represent the ends of two subscribers lines inductively coupled to the two ends of the line sections proper D L between which is inserted the relay apparatus. The relay apparatus compart of the o perprises the relay proper C, with :which, is

associated the double-pole throw-over switch D, the latter being represented by the two arms D D and their associated electromagnetic actuating means d Ihe relay 0 may be a telephone relay of any ordinary construction such as art electromagnet operating amicrophone ass own,

its energizing portion, represented by the terminals C forming part of one or other of two circuits including two contacts 0 c of the double pole switch D, and its rein-.

forcing portion, represented by the termmals U, forming part of two circuits including the other two contacts namely 0 0 of the said switch; The circuit connections and the: construction of the-double pole switch D are such that when one of the relay energizing circuits is'completed through the switch and through a source of variablecurrents due to voice currents transnntted from one subscrlbers hne,,one of the reinforcing circuits of the relay, is simultaneously completed through the switch D and through means whereby the relay magnified currents are transmitted to-the' other subscribers line, and similarly with respect to the otherrelay energizing circuit and'the The sources of variable 'currents'in the relay energizing circuits conveniently consist, as shown, of windings E F of transformers E F respectively, of which the other windings E F are in the lines leading to the corresponding subscribers lines;

In the position of the parts shown in Fig. 1-it is assumed that the subscriber on by which the magnified speaking currents 'from the terminals C of the relay G are transmitted along'the line L to the subscribers line B. So long as the subscriber on line A- continues 'to speak these conditions are maintained. ,When however, the subscriber on line A stops and the subscriber on line B commences to speak the arms" D D of the double pole switch D are tilted in the opposite direction and the trans-.

- former winding F then becomes thesource once they have been thrown over electromagnetically of variable currents by which the relay C is energized while the transformer winding E becomes the means by which the magnified speaking currents from the relay C are transmitted along the line I1 to the subscribers. line A. Y

over-balancing pivoted type so that when by the energizing of the electromagnets d d they remain permanently in -that position until thrown over electromagnetically in the reverse direction by the energizing of-the electromagnets (1 (if.

I The energizing of the two pairs of-e1ectroma'gnets'is due to currentgderived from l sources of steady current "thatbecome au line sections immediately the respective subscribers commence to speak. In connection tornatically switched across the respective with the subscribers line A, the source of steady current shown for the line L con sists of a battery A connected on the one handby way of aheavy inductance A to the i'line wire and on theother hand by way of a front stop 9 and a tongue 9 to the return wire. The tongue 9? is normallykept against the front stop-g by'a spring 9 or by gravity, butis moved away from the front stop and toward a back stop '9 when a controlling electromagnet A? is v energized by a steady curregt'from a'local battery A. A condenser g" revents spark- ,ingat the stops g, g. The circuit of the battery A is completed through a voice closed in the speci cation and; drawings of; my prior.British' Patent No. 9179 of 1912,,

current responsive device A. This 'device may conveniently take the form of a vibration device or jum ing switch such as dis- 7 that is to. say 'a-balanced or pivoted arm forming part. of thecircuit' of the battery A and riding upon a resilient reed. serving armature" to an electromagnet adapte be energized by the voice currents' The actual surfaces at which the circuit of the battery A -is thus rapidity interrupted: are

preferably composed shown in the fragmentary Fig. 1

- and the battery for providing a rent in the line is also inserted corresponding over the'switch arms. T carbon, When voice currents from the subscriber s line A are inductively transmitted to the electromagnet of the jumping switch A, the armature of this switch vibrates and the balanced arm dances upon it, thereby destroying or reducing the steady current normally flowassume the position shown in Fig. '1. The

right hand part of Fig.1 corresponds to the left hand part, the jumping siwvitc'h B", heavy inductance Bt, and battery B corre-' sponding to the parts A", A and -A --respectively; similarly the post oflice relay B its tongue and stops. 7 v

a The invention is not, of course confined to,

'80 switch Dis electromagnetically actuated to 4 corresponds to the "electromagnet A*, with The switch arms- D 'D may be of the the means'above described for enabling the voice currents in the subscribers lineA to be transferred to the transformer E and to effect the automatic throwing over of the arms of the throw-oven switch. For'example, the inductance A might'be connected-at one end to the battery A and at the other end to the mid point'of. an induction coil 'A connected across the line, the other pole of the battery being connected to: earth, and an appropriate earth connection made at the other end of the line section, as

obviously the nductance A5 represented in this figure might beomitted.

where it is seen that the electromagnet A,

Another modification is shown in Fig.1",

of Fig. 1, and its tongue and stops are dis-- pensed with, and that one'contact of the umping switch A '1s connected by way vof an inductance A to the mid point-0f an inductance A" connected acrossthe line, and the other contact connected to earth. A corresponding earth connection is, made at the electromagnets d d (as in Fig. 1),

steady curin this earth 'connect1on,an advantagebeing that the strength of the current at the contacts of the "switch A is considerably attenuated and sparking is thereby minimized. In this arrangement (Fig. 1?*) ,it'is to be noted that the four electromagnets controlling the switch arms D- D? and thatwhen either subscriber speaks'the pair of electromagnets is .temporarlly eenergized,' thus allowing the remaining pair to predominate and throw Thejumping switches A B ma b 3 are normally energized seams ated at any point in. the respective line sections, either close up toithe relay. apparatus or close up to the subscribers line, but/in orderthat they mayrespond promptly and readily to; voice currents, they are preferably placed close to their respective subscribers lines as shown: in Figs. 1, 1 and 1 so as to be actuated by the voice currents before they suffer appreciable attenuation.

The electromagnet. winding of each jumping switch may be connected across the line and return wires of the lineproper as shown in Fig. 1; disturbances in the line, however, such for example as arise from induction and from. currents from the relay 0' are liable to actuate the switches,

and I therefore prefer to protect" each switchfrom such disturbances by constituting its electromagnet winding the bridge or part of the bridge of a bridge connection as shown in Figs.. 1, 1 and 2, as will now be explained with reference-to Fig; 1. Re-

ferring for convenience of description to-the left hand. end of the-figure, itis seen that theelectromagnet winding terminals of; the jumping switch A s are connected. or bridged acro'ssthe bridge arms A of a bridge connection. One end of each bridge arm is connected to the line. proper L and the other end is connected to part of the transformer winding by which the line L is inductively coupled to the subscribers line A. A represents an artificial line which is more or less a copy of the sub- 1 scribers line with resistance and induct.- anceat the end similar in values to those of the subscribers telephone ,set. Consequently, when voice currents in thesub- 1 scribers line A are transferred by the trans formerto the line proper L the jumping switch A is actuated and producesthe resultsalready described, but any currents passing backward along the line divide at the apex of the bridge connection and do 1 not affect the jumping switch; oronly to a slight extent.

From the foregoing description of .Figs.

'1, 1 and 1 the system represented-by Fig.

- .03 respectively operate in a similar manner to that described in. connection with: Fig. 1,

but it: is to be observed that a single source of steady current (battery X) serves. for bothlines'Land L. U

jumping switch B to operate.

double pole switch arms D D have already,

In. the arrangements and methods of connectionhitherto described, the operator at the relay station is unable to attend to any adjustment that may be required in the jumping switches A B and their acces- If desired, however, the arrange-- sories. ment may be modified to render this possible, as shown for example in Fig. 3, where the jumping switches A, B are shown close up against the transformers E and F respectively at the relay station. It will be understood that when voice\currents traverse the line L, the jumping switch A destroys or reduces the steady current from the battery A with the result that the electromagnetic devices controlled by the jumping switch B predominate and the double p0 e switch is thrown over into the position shown in'the figure. Consequently the voice' currents operate the relay C, and the rein- I forced currents are transferred by the transformer F to the line L". Corresponding effects take place. if voice currents traverse the line L. It is however to be observed that the reinforced. voice currents transferred through, say, the transformer F to the line.L,, cause the balanced arm of the Since the been thrown over and are of the over-balancing type, the operation of thejumping switch B is of .little importance provided this switchis not by chance active for an instant during which the switch A is quieseent.- If the latter event'took place the switch A. would causethe switch arms D D 'to rock 'into their alternative position,

the voice currents inthe line L would then be unable to become reinforced by the relay. In order to avoid this occurrence several precautions may-be adopted. According to' one method the reinforced voice currents from the relay C are tapped by means of a transformer, as shown at H in Fig. 3, and the tapped portion of the current is made to traverse two coils A, Bf", which are associated with the jumping switches'A B respectively in such a way as. to. cause-their pivoted or balanced arms to dance and thereby insurethat both switches are'kept in an active-condition so long as voice 'currents are passing through and being reinforced by the relay. This. arrangement may in some cases present a defect in that, whereas the coilsA"".-B"* are traversed by the same current, the energizing winding of the jumping switch A is traversed by attenuated voice currents, when the energizing winding of the jumping. switch B is traversed by the relay augmented voice cur;

rents, and similarl'y' the switch B is traversed by attenuated currents when A? is traversed by augmented voice currents, the

result bein that ,the two jumping switches lbs are not an jectto exactly the same conditions. A.preferable arrangement, therefore,

is to so arrange the coils A B that they oppose the action of the respective energizing windings of the jumping switches. If, then, the electrical characteristics of the circuit of the coils A B are made equal to those of the lines L and L, as can be done by introducing an artificial line J of appropriate electrical value in the circuit of-the coils A" B, the currents in the coil B will neutralize or oppose the currents in the energizing winding of the switch B when the reinforced voice currents are being transferred to the line L", whereas the similar currents in the coil A will predominate over the attenuatedcurrents in the energiz-v ing winding of the switch A, thus insuring that the switch is kept quiescent and the switch A is kept active so'long as voice currents are traversing. the line L. Similarly when, voice currents are traversing the line L", the switch B is kept active andthe switch A is kept quiescent. In the arrangement just described, the, coupling ofthe coil A with the energizing winding of the ,switch A, and the coupling of the coil B with the'energizing windingofthe coil B,

- must not be very close, slnce otherwise .coils ddi, (1 (1, are supplied with current I ters Patent. of the United States is:-

' 1. In a telephone relay system betweenenergy might be transferred back into the lines L or LP. Instead of having to avoid the too close coupling above referred to, a

modified system may be adopted as shown in I 'Fig. 4;. In this arrangement, the relay augmented current tapped'by way of the transformer H is made to: operate a jumping switch C which controls the circuit of a battery 0* by means of which the energizing by way of the jumping switches A B". So

long as the relay is operating to reinforce" voice currents arriving from either direction, say from the line L, as represented by the drawing, the jumping switch C 'is active and the steady current that might otherwise flow from the battery 0" inthe coils 11 is destroyed or reduced, so that in the event of a momentary quiescence of the j ping switch B the arms of th double pole switch are not thrown over. b

What I claim a'nd desire to secureby Lettwo terminal stations, the combination with relay apparatus, relay energizing circuits through-which voice currents from the terminal stations may pass, and rela circuits through which the relay magnifi currents may pass, of switching means normally assuming and maintaining either of two positions in one of which the rela V energizing circuit corresponding to one sta ion'is closed and receiving conditions for the distant station are-established, while in theother posi tion therelay energizing circuit for the ment oned station is closed'and recelving' conditions for the first mentioned station are established, and means whereby the voice through which the relaymagnified currents [may pass, of a double-pole overbalancing change-over switch normally assuming and maintaining either of two positions in one of relay energizing circuits which, the relay energizing circuit corre-' spondingto one station is closed and receivmg conditlons for the distant station are established, while in the other positionthe relay energizing circuit for the last men-..

tioned station is closed and receiving conditions for the first mentioned station are.

established, and means whereby the voice currents from either terminal station automatlcally cause the change-over switch to assume the position in which the distant station can receive the relay magnified currents, if said switch is not already in that position. 3. In a telephone relay system between two terminalstations, the combination with I relay apparatus, "relay energizing circuits through which voice currents from the terminal stations may pass, and relay circuits through which the relay magnified currents may pass, of a double-pole overbalancing changeover switch normally assuming and maintaining either of two positions in one of whlch, the relay energizing circuit corresponding ceiving conditions for the distant station are to one station is closed and reestablished, while in the other. position it closes the relay energizingcircuit for the last mentioned station isclosed and receiving conditions tion are established, electromagnetic devices for moving the double-pole. change-over switchinte either position, and means whereby voice' currents from either one station cause the-activity of the respectiveelectroma switch into the operative .of the voice currents to the other station.

--4. In a telephone relay system between two termmal stations, the combination with relay apparatus, relay,

energizin' circuits through which voice g currents from the ter- -minal stations may.pa"ss,'and' rela circuits through which the relay magnifie currents may pass, of a double-pole over-balancing change-over switch normally assuming and mainta' either of two positionsin one of which, t e relay energizing circuit correfor the first-mentioned staetic device that moves the change-over position for bring- Y mg about magnification and transmission sponding to one station is closed and receiving conditions .for the distant station are established, while in theiother position it closes the relay energizing circuit forfthe last mentioned station is closed and receiv-- ing conditions for the, first mentioned station are es tablished, electromagnetic devices rents whereby on speaking at either station the corresponding electromagnetic means complete the energizing circuit of the corresponding electromagnetic device and thereby correspondingly actuate the changeover switch.

-5. In a telephone relay system between two terminal stations, the combination with relay apparatus, Ire-lay energizing circuits through which voice currents from the terminalstations may pass, and relay-circuits through Whichi therel-ay magnified currents may pass, of a double-pole overbalancing change-over switch, which in one positionv closes the relay energizing circuit corresponding to one station and establishes 're- 'ceiving conditions for the distantstations,

While in the other positionjt closes the relay energizing circuit for the last mentioned stationand establishes receiving conditions for the first mentioned station, electromagnetic devices for moving the double-pole change-over switch into either position, electromagnetic means forcontrolling the energizing circuits of the said electromagnetic devices, a bridge connection in the line wire between each station and the relay apparatus, and an electrpmagnetic device re s onsive to voice currents included inthe ridge of each bridge connection for operating said electromagnetic means, substantially as and for the purpose specified.

t 6. In. a telephone relay system between w a s' gle relay comnionto both stations, of a double-pole change-over switchwhich in one 7 position closes the relay energizing circuit corresponding to one station and establishes receiving conditions for the distant station," wh11e 1n the other position it closes the relay,

energizing circuit for the last mentioned station and establishes receiving conditions for the first mentioned station, and transformers whereby voice currents from the line-proper of each station are transferred to the corresponding +relay energizing circuit orthe re- 4 electromagnets electrically connected in the .line proper, means for sending a steady'curv lay magnified voice currents are transferred to th eproper according tothe direction of speech transmission, switch actuating terminal stations, the combination with rent through the line to energize the electromagnets, electromagnetic devices for rendering the aforesaid means operative, and devices responsive to voice currents whereb on speaking at either station the correspon ing switch actuating electromagnts become active. o,

' 7. In a telephone relay system between two terminalstations, the combination with relay apparatus, relay energizing circuits through which voice currents from the terminal stations may pass, and relay circuits through which the. relay magnified currents may pass, ofa change-over switch which in one position closes the relay energizing circuit corrresponding to one'station' and establishes receiving conditions for the distant station, while'in the other position it closes the relay energizingcircnit for the last men-- tioned station; and establishesreceiving conditions for the first mentioned station, electromagnets'electrically connected in the line proper from each terminal station, means whereby'the electromagnets become energized, electromagnetic device's responsive to voice-currents whereby on speaking-at either station the circuit-closing means of the electromagnets become operative in closing theirenergizing circuits and thereby bring about actuation of the change-over switch, and meanswhereby the efi'ect ofthe relay-augmented voice currents on the voice-currentresponsive device that is associated with the section of the line to which such currents are being transmitted is neutralized or coun eracted for so long as the relay apparatus continues to operate for the directionin question.

8. In 'a telephone relay system between two terminal stations, the combination with a single relay common to both stations, of a double-pole: change-over switch which in one positiontcloses the relay energizing circuit corresponding to one station and establishes receiving conditions for thedistant station", while in the other position it closes the relay energizing circuit for the last mentioned station and establishes receiving conditions for the first mentioned station,electromagnets associated with-the switch; and electrically connected to the line proper from each terminal station, a batteryconnectedto sendi adivided steady current along the line toener gize the electromagnets,battery circuit closing means, and electromagntic devices res onsive" td voice-currents whereby on sperm 'ng at either station the battery circuit closing means close the battery circuit.

,Jn testimony whereof I aflix my signature" in presence of two witnesses.

a SIDNEY GE ORGE BROWN.-T

Witnesses:

T. Samar Wannm, E. C. WALKER;

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