US850434A - Telephone apparatus. - Google Patents

Description

PATENTED APR. 16, 1907.

3 SHEETS-SHEET 1.

klwemtoz fitter/"M 3 K. KOHN. TELEPHONE APPARATUS.

APPLIOATION FILED FBB.11, 1904.

v No. 850,434.

No. 850,434. PATENTED APR. 16, 1907.

. K. KOHN. E

TELEPHONE APPARATUS.

APPLICATION FILED FBB.11, 1904.

3 SHEETSSHEET 2. 1

N .850,434. 4 PATENT'ED APR,16, 1907.

0 K. KOHN.

TELEPHONE APPARATUS. APPLIUATIOH FILED FEB. 11, 1904.

. 3 SHEETS-SHEET 3.

KOBY KOHN, OF NEW YORK, N. Y, ASSIGNOR OF ONE-HALF TO LOUIS KSENSKY, OF DENVER, COLORADO.

No. stones.

Specification of Letters Patent.

Patented April 16, 1901;.

Application filed February 11, 1904. Serial 1 To all whom it may concern:

Be it known that I, KOBY KOHN, a citizen of the United States,-residing in the city, county, and State of New York, have invented certain new and useful Improvements in Telephone Apparatus, of which the following is a specification;

This invention relates to telephone systerns; and the object of the invention. is to provide simple andefl icient means whereby when one subscriber on a party-line either calls central or receives-a call from central all other subscribers on the party-line will be prevented from cutting in, thereby preventmg any other suliiscriher on the line from overhearing the conversation or any part of it, and thus insuring absolute privacy on the line while in use.

One or the essential features of my invention is that all receivers on the party-line are in open circuits until a subscriber calls or is called, when his receiver-circuit will be,

closed and all other receiver-circuits on the line be prevented lrombeing closed by the respective subscribers until the calling or called subscriber has. finished the conversation and all parts on the party-line have been restored to normal position by an operator at central.

The invention, which may be used either with the local-generator system or the central-enery system for calling, will be fully described hereinafter, reference being had to the accompanying drawings, in which- I Figure 1 is a diagrammaticview illustrating my invention as used in a system employing local generators forcalling central.

Fig. 2 is a diagrammatic view of a portion oi the apparatus employed at each of the substations, showing the parts in a different position. Fig. 3 is a plan view of one of the arniatures employed. Fig. 4 is a side elevation. of'the resetting devices. Fig. 5 is a similar View of a portion of Fig. 4., showing the parts in a dillerent position. Fig. '6 is a diagraminatic view of devices for sending currents over the main-line wires by an operator at central. Fig. 7 is a diagrammatic view illustrating my invention as used. in connection with the central-energy system.

it is to be understood that the invention may be embbdied in an apparatus which may form an attachment to telephones at present in use or itniay be a part of the telephone.

In Fig. 1 I have illustrated diagrammatically the devices employed at a central station and also those at two substations a; and Z). It is to be understood, however, that the invention may be used with four substations on the party-line, of which two will be connected to the line-wires X and X X, the same as substations a, and two the same as sub station I).

A is a generator of any known style for sending out an alternating current, one of such generators being at each substation, and when not in use its armature is out out at N,

which may be considered its normal condivided at each station, and it is immaterial what its polarity nay be so far as concerns its energization by'the generatoiiA, because the current from the latter alternating and will thus operate a magnet of either polarity. At substation a, the magnet (I may be of the same polarity as that at substation b; but il four substations are on the party-line the magnets (-1 at the other two stations will he of opposite polarity to those at stations (1 and 1). Referring 110w to Fig. 1, and assuming a subscriber desires to call central, the gm .5 tor A is operated, and the circuit is close A thereby establishing a circuit as l'ollows: from generator A to wire l wire l contact F brush 0, wire C magnet 1, wire t3, brush (1, contact F wire i brush is, coi1- tact F, wire F to the generator. This will energize the'inagnet U and attract its armature C", pivoted at 3, with the result that the generatoncircuit will be broken. through the magnet C at F F. This is done to prevent the return of C", as the current being alternating andgniagnct polarized such action would result were it not for this break in the circuit. The receiveucircuit will be closed at G" G and G and the brush P" will be r 7 J I p engaged with contact r". (iii-rent :lroin the enerator A will then lass towlrc l wire F". n v I line-wire J\ to wire il at the central station 7 brush ll", contact ill, brush ii wire ll", contacts ll. and-ll, wire 11?", through iiiagziet il wire ll, to luie\viii'e X R, to wire i brush F contact l wire l in 'cuci-ai'or r.

This current will energize magnet ii and art-- tract its armature ll, which is pivoted at 11 will he released to iiolily ceuioc net H will be broken at H, H, and H and' at the same time contact H will be engaged with brushes H and H and contact H with brushes H H and H At each substation .there is a magnet E, the armature E" of which is pivoted at 5 and the movement of the armature E is resisted by a comparatively weak spring E and also by a stronger spring There is an arm B pivoted at one end, ad j acent to the armature E and its free end is provided with a iinger 1), adapted to engage a linger e on the free end of the armature E, and these fingers are normally held in contact with each other by a spring B, which normally tends to move the free end of the finger b and which movement is resisted by the finger a when the armature E is in its normal position, as shown in Fig. 1. A stop 20 limits the movement of the armature E? under the influence of its spring E and a stop 21 will limit the movement of the arm B under the influence of its spring when the fingers e and b have been disengaged. The arm' B carries the contacts F and F already referred to, and also contacts E and Referring now to the central station, when the magnet H h been operated by the generator('.urrent, already described, current from a battery H will be sent over the linewires X X and X and through the magnets E at the respective substations, as follows: from battery 11 to wire H brush H contact H brush l1, wire H, wire H to wire X X, or from contact H to brush H wire H to wire X. From the wires X X and X, respectively, current will pass to wire E, magnet E, wire E contact E, brush E, wire to the groundfthence to wire I1, brush H contact H brush H wire H back to battery H over wire H will pass through magnet H wire H, spring-contact H, contact 11 wire H' to battery, and thereby insure the attraction of the armature H after the current from th generator A has been cut out at H H and ll. until the circuit through the magnet IP is broken at H IF, as will be referred I to hereinafter. The current passing from the battery ll?" over the wires X X and X will thus energize the magnet E at each of the.

substations on the line. This current, however, is of sullirient strength only to overcome the resistance of the x pring E" to the movement of the armature It", and the latter will move unlilit engages the spring El, which will stop its further movement. This movement, however, is sullirient to disen- "v the finger e from the finger b, and the 1 ii will i hen more under theiniluenee ol its ng l3 until it is arrested bythe stop 21, as

min in Fig. 2 ol the drawings. "lhismove-.

' men? of the arm will disengage contact E Part of the current passing from brush E, and the circuit through magnet E from the battery H will be broken at this point; but another circuit will-be established through E, including magnets 'C and the bell D in series, as will be hereinafter described. The additional resistance of C and D-say about one thousand ohms eachwillfbe too much to enable the weak current to energize E sufficiently to hold its armature against the action of spring E", andjthe armature Ewill return to normal position, as shown in Fig. 2. .As the movement of arm B is the same at all substations, it will be seen that the generatorcircuit at each substation for its magnet C will be broken at C and F and atC and F and therefore no other subscriber on the line can close his receiver-circuit at G, G, and G until after the/parts are againr'estored to normal position, as will be explained hereinafter. A metallic circuit at the calling s'ub station has, however, been establishedas follows: From l ne X X to wire G to Wire G through receiver G to contact G, and, assuming the receiver has been removed froinits hook. hrough the hook to wire G, brush G cent: o G, brush G wire G wire G, wire F to wire X, and the calling subscriber can thus talk with central and all the other subscribers, being unable to close their receivercircuits, cannot hear any. conversation that may be carried on. As shown, the receiver circuits are each provided with the usual secondary of an induction-coil I in close proximity to the usual primary of an inductioncoil J. When central answers the calling subscriber, a jack or plug is inserted at H, which will break the circuit from battery H at H and H", thereby denergiging the magnet H which will release its armature, and the-latter will be restored to normal position by the spring H. The drop H may also be too restored to its normal position, and then the operator at central may withdraw the jack from H and permit the spring-contact Hto engage H and then the circuit from the generator'A at the calling substation will be again completed toenable the person at such substation to ring off, after which the operatorat n central will restore the parts at the several 5 substations to normal position, as will be explained hereinafter. Assuming now-that the parts-are in normal'position and central desires to call up a substationsay a-the opera tor at central will, first send a. comparatively I weak current over the lines X X and X to en ergize the magnet E at each substation to re-v lease thearms B and bring them to the position shown in Fig. 2. 1

As before stated, the magnets Cat the substations are polarized, and we will assume. that the magnets at substations wand b will respend to a current and those at e a 11d d to. a also a bell D of the same Vpolarity as the mag; net at its substation. hen, therefore, the

current, At each substation, there is this result.

operator at central desires to callsubstation a, he will send out a current over the line X to wire E, magnet E, wire E", contact E brush C, wire C through magnet O to wire,

C, brush C, contact C, brush Cl, wire C through hell i) to wire 0, wire E to the ground and back to central. This will ring bell l) at substation ct, energize magnet C at the same substation, and attract its armature C, and thereby close its receiver-circuit at G G", and G", and when the person at this substation lifts the receiver from the hook the receiver-circuit will be completed, as before described. The magnet E at substation a is also connected to the wire X; but the magnet G and bell l) at this substation will not respond to a current, They would, however, respond to a current sent over the wire X, and the magnet C and bell D at substation I) will respond to a current sent over wire X X, while those at substation (1 will respond. to a current sent over wire X X. As the arms B at the respective substations have been operated, no other substation on the line can call central or hear the conversation except in the case where the call is from one substation to another on the same line.

It is desirable to provide s01i1e n1eans for informing a person desiring to can central when the line is busy that such'is the 'fact, and 1 preferably employ an audible Signal for this purpose,- which is operated by'a current from the generator A. As before statled, when a call is sent from central or to central all the amps B are moved from the position in dicated in Fig. 1 to the position indicated in Fig. 2, and then the contact F on said arm has been disengaged from brush C and become engaged with brush K, and a circuit is then established from generator A to wire F contact F, brush F wire F", contact F, brush K, wire K, bell K, wire K to wire F back to the generator A. It then. subscriber operates his generating he will ring the bell K at his substation, and so be notified that the line is busy.

As before stated, the magnet (.7 at each substation is polarized and will attract its armature only when a positive or negatiye cur rent, as the case may be, is sent throiigh it. If after a magnet Chas been energized to attract its armature and close its receiver-cm cuit the operator at central should aecidentally or otherwise send a current of opposite polarity over the line, the armature of the magnet C would be repulsed and its receivercircuit broken, and it is therefore desirable to provide means to prevent this action.

h'lai'iy devices might be en'iployed for this purpose, and. in Figs. 3 and 4 l. have illustrated a preferred means for accomplishii'ig ing one pole of the magnet C. l proyide an In Fig. 4- the parts are shown in normal position with the armature (1" cngagarm 30 of non-magnetic material and. to which I attach the various contacts, such-as F and G, in any'convenient manner and at trate in these figures. This arm is provided with an opening 31 of sufficient size to receive the armature C loosely, as clearly shown in Fig. 3. The armature is provided with trunnions 32, rigidly connected to it, and these pass loosely through holes 33 in opposite walls of the opening 31 and will form the pivotal support oi" the armature and also of the arm 30. Near one end of the opening 31 I secure a bridge 3% to the arm, wh ch extends across the opening in position to be engaged by one end of the armature. When the parts are in normal position, as in Fig. 4;, if current of the proper polarity be sent through the magnet the armature will be attracted to the other pole of the magnet and by its engagement with the bridge 34 will carry the arm 30 with it. If the operator at central should now send a current of opposite polan ity over the line, the armaturec will be restored to normal position, but it will move away from the brldge 34, and consequently will not move the arm 30, as there is not suflicient friction between the trunnions and the openings 33 to. move the arm. The arm 30,

therefore, after once being moved by the ar- 9 mature (3 will not be again affected by it un' til after it has been restored to its normal position, as will be hereinafter explained.

I will now describe the means preferably employed for resetting the arm B and the armature C" and the arm 30. The magnet E is utilized for this purpose, and all the resetting is ellected by the movement of the armature E". the armature E its full stroke toward. the magnet E and overcome the resistance of the spring E and therefore a stronger current must be used to effect this result; The means for sending this current over the wires will be described hereinafter. This current passes from the wires X X and X to wires E and through the magnets E. As the path ,is the same in each case, we will describe it in one. The arms B are in the position indicated in F 2. From the magnet E the current passes to wire 15 ,410 Contact E", brush 1, wire (1 magnet C, wire C brush C contact C brush C, wire hell D, wire C, wire E any convenient points, not necessary to illus To effect this, it is necessary to move to the ground, and thence back to central.

This eilergizes the magnet 'E, and its armature begins to move toward it and by the time it begins to overcome the resistance of. spring E" contact E on the armature will be engaged with brush E and a direct circuit from magnet E is established to the round,

as follows: from E to wire E wire L, contact E brush E wire E", and, wire F When this circuit-has beeniestablislied, the arm B will have begun to move toward its normal position, and brush C will be disen- We will now refer to Figs. 4 and 5, which illustrate a preferred means for transmitting movement from E to the arm B and to the arm and armature 0 In Fig. 4 the parts as illustrated in full lines are in normal posi-* tion. If the armature (3 is operated, the end w of the arm 30 will move up into close proximity, but not into contact with the end of the set-screw 36 in the armature E". There must be sufiicient space between them to permit the movement of the armature E to release the finger efrom finger b, as indicated in dotted lines, and when these fingers are disengaged arm B will move into the po sition indicated by dotted lines, when itwill.

engage the stop 21, (shown in this case as a pivoted bar resting on a stud 37.) A bolt 38 is connected at one end to the stop andextends loosely through an opening in the armature fi'near'one end thereof. This bolt is provided with two adjustable' stops, (shown in' this case as nuts 39 and 40,) one above and the other below the armature E". These stops are so arranged that when the armature is in its normal position neither will engage the armature. When the magnet E attracts its armature to release the fingers e and b, the armature will be free to move until it is arrested bythe spring E without lifting the bolt 38, and this movement will be sufficient for this purpose. When, however, the magnet E operates to reset arm B and armature C", the are re E will make a complete stroke and carry the bolt 38 up to the position shown in Fig. 5, which will move the pivoted stop 21 to a position at right angles to the arm B, and thereby force the latter back to its normal posi-' tion. When the armature E is released, the springs will force it back and bring its finger e in position to intercept finger b, and then it will engage stop 40 and'force the bolt 38 downward, and thereby disengage the stop 21' from arm-B, and the stop 21 and bolt 38 will then complete" their returnto normal position by gravity. -The complete movement of the armature E under the influence of magnet E will also cause the set-screw 36 to.

engage the end as of the arm 30, and thereby restore it and the armature C to normal position.

Various means may be devised for sending the necessary currents over the wires X and X X by the operator at central, andin Fig. 6

' I have 'shown apparatus which may be used for this purpose. Thus for sending the strongest current over the wires X and X X for energizing the magnets E to efiectthe resetting operation I provide a battery or other source of electrical supply S of the necessary capacity and provide a switch-lever S, having contacts S and T insulated from each other. Brushes S and S", adapted to be engaged by the contact S, are respectively connected to'wires X X and X. One pole of the battery S is electrically connected by a wire S to the contact S and the other "pole to the grornd. When the switch-lever S is moved to engage contact S with brushes S and 8*, current from the battery will be sent over both line-wires X X and X through magnets E to the ground, as already described, and back to battery A portion of the same'battery S may be utilized for energizing magnets E for the purpose of releasing the arms B, which does not require so strong a current. Thus the contact T is electrically connected by a wire T Witha portion only of the battery, as shown 'in Fig. 6. Two brushes T and T, adapted to be engaged by contact T, are respectively connected to wires X X and X, and when switch-lever S is moved to engage contact T with brushes T and T current from a por- *tion of battery S will flow over wires X X and X through magnetsA to the ground and back to the battery S.

The current for energizing magnets C and bells D is preferably a continuous vibratory current, and in Fig. 6 I have shown one means for sending a current of this character over the lines X and X X. Thus the line X is connected to a pivoted switch 0 by a wire 0, and the line X X is connected to a similar switch 0 by a wire 0". A battery or other suitable generator 0 is provided, and the positive polether'eof is connected to a contact adapted to be engaged by either of the switches O or O and its negative pole is connected to a contact 0, adapted to be en. gaged by either of the switches 0-01 0 A commutator is provided in each connection betweensaid contacts and the battery, and the latter is connected to the earth. If the switch 0 be rocked to engage O, a negative current will be sent over line X, through magnets C, and-return by the ground to battery 0 If switch Oengages O, a positive current will be sent over line X and return through the grouml to'battery 0. By opcrating switch O ithe same effects take placeover wire XX.

' Referring now to Fig. 7, wherein I have illustrated diagrammatically an apparatus at central and an apparatus at one substation on a paty-line in a central-energy system, it will be observed that the magnets E and C are empldyed insubstantiallythe same relations as-in the system heretofore described.

The generator F and its circuits are, however, omitted. celver G from its support1ng-hook will serve In this case the removal of the re."

amaze to send a signal to central and automatically 1 ated, however, the circuit will be closed at K send a current from central through the magnet (l to closeits receiver-oircuit.

Assuming the receiver G to be lifted from its hook l)", a circuit will be established as follows: from book ll to wire 1), line-wire- X X, through battery M at central, contacts M and M wire M,- magnet M, wire iv to line-wire to wire U brush C contact C, brush i l, wire (1, magnet 0, wire C brush (3 contact (1, brush C wire C contact 6"", to hoolr 17*. Current will then flow through magnet C from battery M and energize said magnet, thereby attracting its armature C and closing its receiver-circuit at G, G and (3. At the same time the mag net lil wili be energized and attract its armature M", which will release the drop and at the same time engage contact M with brushes M and M and contact M with brushes N and M Current from the battery M will now flow over both line-Wires X and X X to energize all the magnets E on the party-line, as before described, that for line X X flowing direct from the battery to the liIlGrWIlIG X X and returning through the magnets E, connected to that wire, the gr0und,,and contact- M. and brushes M and M to the battery and that for line X flowing from the battery.

over wire M to brush M contact M brush M and wire M to wire X and returning through the magnets E, connected to that wire, the ground, and contact M and brushes M and M to the battery. Part'of the cur- .rent over M will also pass through magnet M back to the battery, and thereby keep the magnet energized and insure the operation of all the magnets E.

It will be observed that the magnets C are connected across the line-wires X and X X, and each will respond to the action of current from battery M irrespective of its polarity, when its circuit is closed by its hook D engaging the contact C To effect this action, however, it will be necessary to make slight changes in the comiections. between magnet C and the brushes C and C Thus, assuming that magnet C-in Fig.7 will respondto a negative current a magnet!) on the same line polarized. to respond to a positive current would have 1ts wire C connected to brush =3 and1ts WlIB C connected to brush C, thus sending the current through it in a reverse direction.

So far as sending out currents from central by an operator thereat for f operating magnets E and C for thepur oses already described in connection with ig. 1 is concerned, the operations will be the same. In this case the circuit for the signal-bell,Kis

somewhat differently arrangedfrom that in Fig. 1 and is as follows: All bell-circuits are normally open at K and C and at the hook D and contact C. When the arm B is operand C and then it a subscriber lifts his receiver from the hook at a substation other than one that may be using the line a circuit will be closed through the bell at such substation as follows: from hook D to contact C Wire C wire C contact C brush K,

wire K through bell K to wire K brush K,

contact K brush K", wire K local battery K, to hook D At any substation, however, where magnet C has operated to close its receiver-circuit the local bell-circuit will be broken at K K and K, and the removal of the receiver from the hook will not result in the ringing of hell K.

Without limiting myself to the precise details j of construction illustrated and described, I claim- 1. In a telephone system" for party-lines, the combination with the main-line wires leading from a central station, of a series of telephone-receivers each independentl connected to the line-wires by an open e ectric circuit, a polarized magnet and an armature at each substation for closing the circuit. of its receiver, and a generator at each substation under the control to the person thereat for sending an alternating currentthrough said magnet to energize it, substantially as set forth.

'2. In a telephone system for party-lines, the combination With the main-line wires leadingfrom a central station, of a series of telephone-receivers each independently con nected to the line-wires by an open electric circuit, a polarized magnet and an armature its receiver, and means at each substation under the control of a personthcreat for sending a current through said magnet to energize it," to first close its own receiver-circuit, and then close a circuit at the central station for sending a current over the main.- line wires to operate devices for preventing the closure of the receiver-circuit at any other substation on the line by a person thereat, substantially as setiorth.

3. In a telephone system fOrparty-lines, the combination with the main-line wires leading from a-central station, ofa series of telephone receiVers each independently connected to the line wires by anopen electric circuit, a receiver-circuit closer at each substation including a polarized magnet and an armature, a signal at the central station, and a generator at each'substation under the 'control of a person thercat for sending an alternating current through said magnet to energize it and cause it to close its own receiver circuit, and also close a circuit to the central" station to operate the signal thercat, sub stantially as set forth.

4. In a telephone system for party-lines, the combination with the main-line wires leading from a central station, of a series of the non-polarized magnet for electrically con- 'telepl1onereceivers each indepeinlently con nected to the line-wires by an open electric circuit, a receiver-circu t closer at each substation including a polarized magnet and an armature a signal at the central station, and a generator at each substation under the control of a person thercat for sending an alternating current through said magnet to energize it and cause it to close its oWn receiver-circuit, and also close a circuit to the central station to operate the signal thereat, and also close a circuit at the central station for sending a current over the main-line Wires to operate devices for preventing the closure of the receiver-circuit at any other substation on the line by a person thereat, substantially as set forth.

In a telephone system, the combination With the main line Wires leading from a eentral station, of a telephone-receiver connected to said line-Wires by an open electric car- ,cuit, a polarized magnet .md an armature adjacent to said receiver, means For sending a current of the desired polarity'through the magnet to operate its armature to close the receiver-circuit, and means for preventing said magnet from breaking said receiver-circuit when a current of opposite polarity is sent, through it, substantially as set forth.

6. In a telephone system, the combination with the main-line WlIOS leading from a central station, of a telephone-receiver connected to said line-wires by anopen electric circuit, a polariz'edmagnet and an armature adjacent said receiver, an arm pivotally supported adjacent said armature and carrying devices for closing said receiver-circuit and means for transmitting movement from the armature to said arm to close the receiver-circuit when the magnet is energized by a current of one polarity but inoperative to move said arm when the magnet is energized by a current of opposite polarity, substantially as set forth.

7. The combination with main line Wires, of a telephone-receiver connected thereto by an open electric circuit, a polarized magnet and a pivoted armature, an arm carrying devices for closing the reccivercircilit, said arm having an opening into which the arm-ature loosely tits and being pivotally supported on the pivots ol' the armature, and a bar secured to the arm and extending across said opening to be engaged by one end of the mature, substantially as set forth.

8. In a telephone system for party-lines,

the combination ot main-line wires leading from acentral station, of as'eries ot' telephonereceivers each connected to the line\\'ires by an open electric circuit, a polarized magnet and arm atnrc at each substation for closing its (),\\'H receiver-eircuit, a polarized bell at each substation, a non-polarrzed magnet at each substation, and means operated by necting the polarized magnet, the polarized bell and itself in series to receive a polarized current over the mam-line wires from the central station, substantially as set forth. 7o

9. In a telephone system for party-lines, the combination of 1nain-line Wires leading from a central station, of a series of telephone-receivers each independently connected to the line-Wires by an open electric central station, over the line-wires to energize the non-polarized magnets, means operated by the non-polarized magnets to prevent the closure of their respective receiver-circuits by persons at the respective substations, and

means for sending a polarized current from the central station for operating the polarized magnets selectively to close their respective receiver-circuits, substantially as set forth.

'10. In a telephone system for party-lines,

the combination of main-line Wires leading 0 from a central station, of a series of telephonereceivers each independently connected to the main-line Wires by an open electric circuit, a,polarized magnet and armature at each substation for closing-its own receiver 5 circuit, a polarized bell at each substation, a non-polarized magnet and armature at each substation connected to one of the line-Wires, the said magnets and bell being normally deenergized, and circuit-closing devices con- 10o trolled by said non-polarized magnet for electrically connecting the bell and magnets at each station in series, substantially as set forth.

11. In a telephone system for party-lines, to

the combination of main-line wires leading from a central station, of a series of telephonereceivers each independently connected to" the main-line Wires by an open electric circuit, a polarized magnet and armature at each substation for closing its own receivercircuit, a polarized bell at each substation, a nonpolarized magnet and armature at each substation connected to one of the line-Wires, the said magnets and bell deenergized, a'pivoted arm carrying circuitclosing devices normally biased to move in onedirection and restrained from such movement by the armature of the non-polarized magnet, and means for sending a current through said non-polarized magnets for releasing said arm to close circuits for connecting the bell and nn'ignets at each station in. series, substantially set forth.

12. In a telephone system for party-lines,

the combination of main-line wires leading from a central station, of a series of telephone receivers each independently connected to the main-line Wires by an open electric cir cuit, a polarized magnet and armature at being normally 115 each substation for closing its own receivercircuit,ia polarized bell at each substation, a non-polarized magnet and armature at each substation connected to one of the line-Wires, the said magnetsand bell being normally deenergized, a pivoted arm carrying circuitclosing devices normally biased to move in one direction and restrained from such movement by the armature of. the non-polarized magnet, means for sending a current through i said non-polarized magnets for releasing said arm to close circuits for connecting the bell and magnets at each station in series, and means operated by the non-polarized magnet for restoring the arm to normal position, substantially as set forth.

13. The combination with the main-line wires, of a telephone receiver connected thereto by an open electric circuit, a magnet C and armature for closing said circuit, a bell, a second magnet E connected to one of the line-Wires, an armature for said magnet, said magnets and bell being normally out of circuit with each other, a pivoted arm carrying circuit-closing devices, said arm being normally biased to move in one direction and restrained from such movement by the armature of the magnet E, means for sending a current through the magnet E to attract its armature and release said arm to close circuits for connecting the said magnets and bell in series, substantially as set forth.

' 14. The combination with the main-line Wires, of a telephone receiver connected thereto by an open electric circuit, a magnet C and armature for closing said circuit, a bell,

a second magnet E connectedto one of the line-Wires, an armature for said second magnet, said magnets and bell being normally out of circuit with each other, a pivoted'arm carrying circuit-closing devices, said arm being normally biased to'move in one direction and restrained. from suchmovement by the armature of the magnet E, means for sending a current throng 1 the magnet E to attract its armature and release said arm to close circuits for connecting the said magnets and bell in series, a pivoted bar forming a stop to limit the movement of the said arm, and connections between said bar and the armature of the magnet E for restoring said arm to its normal set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

' KOBY KOHN.

position, substantially as Witnesses C. A. Ar uNsoN, F. L. B. JENNEY

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