US556007A - Automatic telephone exchange system - Google Patents

Description

No Model.) 7 Sheets- Sheet 1.

M. PRBUDENBERG.

AUTOMATIC TELEPHONE EXGEANGB SYSTEM. No. 556,007. Patentedl Mm. 10., 1896.

l Illllll (No Model.) 7 Sheets-Sheet 2.

M. FREUDENBERG. AUTOMATIU TELEPHONE EXCHANGE SYSTEM.

Patented Mar. 10, 1896.

ANDREW E GRAHAM PNDTO'LYTNU. WASHINGTQIL D.C

(No Model.) m 7 sheets-#sheen E.

M. FREUDENBERG.

AUTOMATIG TELEPHONE EXCHANGE SYSTEM. No. 556,007. rPatented Mar. 10, 1896.'. FI [5.7-

7 Sheets-Sheet 4.

(No Model.) v

M. PREUDENBERG. AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

Patented Mar. 10, 1896.

Fill@` (No Model.) 7 Sheets-Sheet 5. M. FREUDENBERG.

AUTOMATIC TELEPHGNE EXCHANGE SYSTEM.

No. 556,007. Patented Mar.10, 1896,.'

Willijf (No Model.) 7 Sheets-Sheet 6.

M. FREUDENBERG. AUTOMATIG TELEPHONE EXCHANGE SYSTEM. No. 556,007. Patented Mar. 10, 1896.

FIEIE.

7 Sheets-Sheet 7.

(No'Model.) f

M, PREUDBNBERG. AUTOMATIC lTELEPHONE EXCHANGE SYSTEM.

No. 556,007. PatentegMar. l0, 1896.'

mi Ef" NiTnn T'A'rns .'ATnNT Fries,

Morsn FREUDENBERG, or PARIS, FRANCE, AssIeNOR To ROGER WILLIAM WALLACE, or LONDON, ENGLAND.

AUTOMATIC `TEliEFl-IONra--laxcsHANe|: SYSTEM.

SPECIFICATIONforming part of Letters Patent No. 556,007, dated March 10, 1896. Application iiled J'nuary l0, 1896. Serial No. 574,934. (No model.)

To @ZZ whom, t may concern:`

Be it known that I, Mose FREUDENBERG, of Paris, France, have invented certain new and useful Improvements in Automatic Telephone-Exchange Systems, as fully described in the following specification.

This invention relates to improvements in telephone systems.

As is well known, the telephonie communi- 1 o cations between the subscribers of a telephone system are at present obtained by the medium of special officials or attendants posted at the central or district stations and whose duty it is to establish the communica-tions according to the instructions given to them by the subscribers.

In a prior patent I have described a telephonie self-communicating system which allows any subscriber to place himself automatically in communication With any other subscriber Without necessitating` the intervention of special attendants and irrespective of how large the number of subscribers of the system may be.

The present invention relates to certain iniprovements which I have applied to this automatic telephone system with the object of simplifying the function of the apparatus and of diminishing for one and the same number of subscribers the number of plates arranged at the central station.

According to the invention described in the speciiication of the prior patent, No. 546,725, of 1895, granted to myself and to Salomon Berditschewsky, for each subscriber at the central station one plate is provided upon which as many metallic contacts are arranged as the system has subscribers. It follows therefrom that a system of, say, eight thou sand subscribers is provided with eight thousand plates at the central station. In my new system this number of plates is considerably reduced and is only equal to what we may term the maximum regime of the system, by which I mean a number equal to the maximum number of conversations taking place at the same time. Let us take an example in order to render this definition clearer.

Suppose a system of eight thousand subscribers. Suppose that it has been found that in no case more than six hundred conversations take place sim ultaneouslyin the system. Then the maximum regime of the system will be equal to six hundred. This regime evidently varies according to the countries, towns, and districts in which the system is located. Taking this as granted, and before entering into the thorough study of my new system, I shall rst of all explain the principle upon which the same is based. Each 6o subscriber has at his place an instrument, otherwise called a subscribers post, very nearly similar to that which I have described in my prior automatic-telephone patent, and the wire which passes from each subscribers local instrument ends at the central station in a carriage or wagon which is capable of being displaced above a certain number of beams or levers. Each of these beams or levers is connected byawire to a contact-plate 7o which is identical to that of my automatic telephone system, and which is consequently provided with a number of contacts equal to that of the subscribers. The contacts of subscribers in all the plates are united by a wire to the movable carriage or wagon which corresponds to the said subscriber, so as to be connected to the line which passes from the subscribers instrument to the carriage or wagon.

Any subscriber desirous of entering into conversation with any other subscriber of the system causes the carriage or wagon in which his conducting-wire of the line terminates to be displaced by the passage of a current, until this carriage or wagon is thrown in contact with a beam or lever, the result of which is to allow the subsequent currents sent by the subscriber to arrive at that plate which is connected to the beam or lever. On then oper- 9o ating as described in the aforesaid specification the subscriber can pass the pin of the plate upon that contact which corresponds to the subscriber with whom he wishes to be placed in connection, and thus the communication between the two subscribers is established.

As willbe seen, the economy of my new system consists in having a limited number of plates, each of which corresponds to a beam 1 oo instead of corresponding to a subscriber, as in my prior patent. To sum up what I have vro - maximum regime of the system.

Having thus explained the principle upon which my new telephone apparatus is based, I will proceed to describe in detail all the arrangements which I have contrived for putting this apparatus into practice, without, however, again describing those arrangements which are already employed in the automatic telephone system described in my prior patent.

In order to render these following explanations as clear as possible I have represented my new automatic telephone system, as an example, in thc accompanying drawings, in

which- Figure l is a longitudinal view of a wagon or carriage and the rails or track on which it moves, the same being located at the central office and connected with the subscribers linewire. Fig. 2 is a plan view thereof, and Fig. 3 a transverse section on the line 3 a of Fig. 1, looking in the direction of the arrow. Fig. fr is a detail view of one of the beams or levers with which the carriages can be brought into contact. Fig. 5 represents in detail the front of a carriage or wagon, showing the same in contact with a beam or lever. Fig. 6 is a detail view showing the carriage at rest at the terminus of its track. In this figure certain parts of the carriage are omitted in order to show more clearly the electromagnet and the movable plate which are arranged on the carriage. Fig. 7 isaplan view of a special switching device which is inserted in the circuit of the line-wire of each subscriber, and which is arranged at the place where the line-wire enters the central station. Fig. 7bis is a diagrammatical plan View of the switching device or commutator which is placed at the side of each carriage or wagon and controls the motor or dynamo which produces the displacements of the carriage or wagon, as I shall explain hereinafter. Figs. 8 and 9 are a plan and sectional view, respectively, representing the constructional details of this switching device or commutator. Figs. l0 and ll are a plan and a sectional view, respectively, of the commutator or switching device which is placed upon each plate at the central station. Figs. l2 and 12L are diagrammatic views of a telephonie installation according to my improved system, each figure showing two subscribers apparatus as connected with the central-office apparatus.

I will divide the explanation of my apparatus in the following manner: iirst, the description of the apparatus arranged at the subscribers station, of the carriage and of its track, of the beams and of the auxiliary mechanisms; second, the description of the switching device at the central station; third, the operation of the apparatus when taking as an example the system of four subscribers,

as diagrammatically represented in Figs. 12 and l2a of the drawings.

In the apparatus arranged at each subscribers place the same mechanisms are provided as in my prior patented apparatus, and we find therein also the four buttons or knobs Vl V2 V3 V4, the effects of which I will repeat herein. Pressure upon the button or knob V1 causes a series of positive currents to be sent over the line. Pressure upon thc button or knob V2 causes a series of negative currents to be sent over the line.

currents produced the displacement of the carriage from the plate following the line of the abscissae and that of the ordinates. They have the same effect in the present apparatus, as I am going to explain hereinafter when describing the function of the apparatus. The buttons or knobs V3 and V4, which, in my previous apparatus were employed to produce a series of positive and negative currents, cause simply two positive currents to be passed, one of them produced by the button or knob V3 and the other by the button or knob V4.

As indicated in Fig. l2, the buttons or knobs V3 and V4 are arranged in the following manner: The button or knob V3 actuates a rod nl, which can turn on a pivot. At the extremity of the rod nl three fingers or projections n, n2, and as are arranged, which, when the knob or button is acted upon, can be respectively placed into contact with the three metallic plates n4, a7, and 019. The platen* is connected by the wire 60 to the positive pole of the battery and the finger or projection n2 is connected to the line-wire l through the wire GI. Consequentlya positive current passes from the subscribers apparatus, arrives at the central station, where it produces the effects which I am going to explain hereinafter, and passes back through the earth, the wire G2, the iinger n3, the plate a7, and returns through the wire G3 to the negative pole of the battery. The contact of the finger a8 and of the plate an is utilized, as in my previous apparatus, for completing the circuit of the electromagnet FG, which is actuated by the controlling-current automatically sent through the plate of the central station to the subscribers apparatus.

rlhe arrangements for the button V"L are absolutely identical and apart from the modifications which I have just mentioned. The apparatus or post of the subscriber is the same as that fully described in the aforesaid specification, and in this description I shall not again describe all the constructional details of this instrument.

The wire of the line l which starts from the subscribers instrument arrives at the central station at the terminals b1 and b2 of the switch A, Fig. 7. This switch is composed of a rod a, terminating at each of its extremities in two spring-blades a a, a1 a2. The rod a is movable around the pivot B and the length In the previous apparatus these positive and negative TOO IIO

of this rod is so calculated that the same is enabled to occupy the two following positions:

First. The position represented in Fig. 7, in which the blades a' and @zare respectively in contact with the plates b and b2. This is the position which the switch occupies when the instrument of the subscriber in question dees not operate or when this subscriber enters into communication with another subscriber.

Second. The position in which the blades a and d1 are respectively in contact with the plates b and b1, this being the position which the switch takes up when any subscriber enters into communication with that subscriber to whom the switch belongs.

The rod a of the switch is vconnected by a connecting-rod C to a plate D, which latter is pivoted at one of its extremities, dl, while its other extremity is adapted to move between two electromagnets d and d.

lVhen a current traverses the electromagnet d, the plate D will be attracted and the rod a of the switch will take the position which it occupies in Fig. 7. If, on the contrary, a current traverses the electremagnet d', the plate D will be attracted by this latter electromagnet and the rod d of the switch `will take the second position which I have defined hereinbefore.

In no case, as I shall explain hereinafter when describing the communications, can the two eleetromagnets be traversed by a current at the saine time.

As I have said hereinbefore the plates b1 and b2 of the switch are connected by the conducting-wire l to the instrument of the subscriber. The plates b'and Zrare connected by the wire 2 to the metal band or strip which is placed beneath the plates X Y and which in each of these plates has a contact at the point in which each subscribers abscissa and ordinate meet.

The blade a', Fig. 7, of the switch A is insulated from the rod a and is connected by the wire 3 to the electromagnet Cl. The blade a, Fig. 7, of the switch A is insulated from the rod a and is connected by the wire 7 to the blade al of the same switch. The blade al is likewise insulated from the rod a and is, moreover, connected by the wire 4 to the electromagnet CZ. The blade a2 of the switch A is insulated from the rod a and is connected by the wire 5 to the band F parallel with the track for the carriage or wagon upon which the electromagnet E, Figs. l, 2, and 3, is mounted.

The carriage or wagon, Figs. l, 2, 3, 5, and (i, is composed of a platform e, which is mounted upon frictioni'ollers c and which supports the electromagnet E. The frictionrollers roll upon two parallel rails el, Figs. l, 2, and 3, placed at the required distance apart and maintained by supports c2.

The carriage or wagon carries at its lower part and between the rails an internallyscrew-threaded socket G, Figs. l and 3, in which the screw f, Fig. 2, engages. This screw can be actuated bya rotary movement upon itself by the motor or dynamo g1 placed at the extremity of the track el.

As will be easily understood, the effect of the rotary movement of the screw is to produce the displacement of the carriage or wagon upon the track el, and the direction of the displacement of the carriage evidently depends upon the direction in which the screw is rotated.`

The electromagnet E is of course insulated upon the carriage, and the wire which is wound upon this electromagnet is connected at one end to earth and on the other hand to the spring-blade f, Figs. 2 and 3, which rubs upon the widened part f1 of the band or strip F. The widened part f1, as is seen in Fig. 2, only exists upon a very slight length of the band or strip F at one extremity thereof. As soon as the carriage is set in motion, the blade f leaves the part fl of the band or strip F and does not come again into contact until the carriage has returned to its startingpoint. Then the electromagnet E is traversed by a current, it attracts the plate h pivot-ed at h1, Figs. l and 6, upon the platform. Normally--that is to say, when the carriage or wagon is not moving-the plate h rests against the support H under the action of the spring h2, Figs. l and G.

Above the electromagnet E a frame is arranged, composed of two parallel rods 71.', Fig. 6, a hinge or pivot h and a red h3, the section of which has the form of a hook, Figs. 3 and 6.

The axis of rotation 7z'of the frame is supported by the two standards h4 h4, Fig. 3, which rest upon the platform e. The rod h3 carries at each side a prolongation t', and when the carriage is at rest at the extremity of its path the two prolongations t' Il rest upon the two fixed inclined planes I I, Figs. 3 and 6, and in this position the frame is kept horizontal, as indicated in Fig. 6.

As soon as the carriage is displaced, the prolongations t' 1l slide along the inclined planes I I and the hook h3 is lowered and will keep the plate 72. against the electromagnet E, which plate, as we will see hereinafter, had been attracted by the electromagnet at the moment when the carriage or wagon was set in movement.

Upon one of the lateral surfaces of the plate 7L is iixed a horizontal rod j, from which a spring-blade j', Figs. l and 3, is suspended. The lower extremity of this spring-blade rubs against a contact jl when the plate h is attracted by the electromagnet E. The rodj and the spring-blade j are insulated from the plate h and are connected by the wire 9 with a blade K, which is secured to but insulated from a frame M, Figs. l and 3, placed at the front part of and below the carriage or wagon. I will describe hereinafter the arrangements of this frame.

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The blade K serves, as I am going to explain in detail, to enter at certain moments during the displacement of the carriage into contact with the metal plates L, supported by the posts l. The wire 9 which connects the blade K to the rod j and to the springjl, Fig. 3, is likewise attached to a blade m, fixed to but insulated from the platform e. During the displacements of the carriage the blade m rubs upon the band or strip N supported by the standards, parallel to the rails el and el.

The frame M,of which we have spoken hereinbefore and upon which the blade K is iixed, is arranged in the following manner: The same is composed of two parallel rods m2 m2, Fig. 3, united in front by a metallic cross-rail m3. The frame M can turn around the axis m', around which is wound a spring fm" which constantly tends to lift the frame M and to bring the same against the abutment Oiixed to the front of the carriage. In this position the frame is inclined with regard to the carriage, as indicated in Fig. l. The cross-rail m3 is electrically connected by the bars m2 to the platform@ of the carriage or wagon, upon which is fixed, without interposition of insulating material, the spring-blade l), Fig. 2, which during the displacements of the carriage remains constantly in contact with the band or strip F, connected by the wire 5 to the blade d2 of the switch A, Fig. 7.

Below the rails and at distances apart beams R R are arranged. In the example of the drawings I have only supposed that there are two, but this number depends, as I have shown in the beginning of this description, upon the maximum regime of the system. These beams are arranged horizontally and perpendicular to the direction of the rails c1. The beams extend below all the tracks which comprise the system or rather the group of a system under consideration, for in order not to give these beams too great a length all the carriages or wagons may be connected with one and the same system in several groups, which may be placed either' at the central station or in stations which would correspond to what are at present usually called district stations. Each of these beams can be composed, as indicated in Figs. l, 4 and 5, of an upper bar hollowed upon that side of the bar which is turned toward the starting-point of the carriage. The said beam is provided with supports r at distances apart, Fig. 4:, which supports are connected with guides r1 supported by a Vlixed beam r2 serving as a frame. Springs r3 constantly tend to press the beam proper away from the frame r2, and this upper beam remains constantly parallel with the frame r2 owing to the rods 'r which, while engaging with the guides r1, prevent anyinclination of the beam.

part of each beam is made of or coated with metal and is provided at one of the extremities of the beam with a terminal r', Fig. 2, to which a wire 10 is connected, which ends in that plate of the central station which corre- The upper hollowed-out sponds to the beam. If we consider Figs. 12 and l2, it will be seen that the beam R is'connected to the plate X by the wire 10, and the beam R is connected by the wire 1l to the plate Y; If we compare this new arrangement with the apparatus which forms the obj ect of my said prior pat-ent, one may say that the wires lO and 1l play here the part of the former line-wires of the subscribers and terminate in the plates X Y at the same point.

If we suppose for a moment that any one of the parallel carriages which can be displaced above the beams (one carriage corresponds to one subscriber) is set in motion, it will arrive near the beam R, and the frame, or, speaking more exactly, the cross-rail m3 of the frame, will rest in the hollow of the beam R. As the carriage cannot rise above its rails, (owing to the use of any appropriate system of upper or guard rails, which for the sake of clearness are not shown in the drawings,) the beam will descend inv proportion as the carriage continues to advance. When the beam has thus been lowered, the carriage, as I shall explain hereinafter, stops byitself, and if another subscriber causes the displacement of his carriage by sending a current he will not be able to place the same in contact with the already-occupied beam, since this latter is lowered. IVe will see hereinafter the usefulness of this arrangement; but I may here remark that the arrangements of the beam for the purpose of causing the same to be lowered by the contact of the carriage may greatly vary and that the one which I have described herein is merely given as an example.

rIhe displacements of each carriage are obtained, as I have explained, by a motor or dynamo, (each carriage having a separate motor,) and I will now describe the arrangement which I have adopted for producing the movements of the motor in either direction.

For facilitating the understanding of the description I have supposed that the electric motor, which in the example is a small dynamo, would act with one single wire-that is to say, that the return iow of the current to the battery would take place through the earth. In practice this arrangement cannot be realized, because there are no such electromotors yet in existence which act satisfactorily under these conditions; but this defeet may be remedied by modifying the commutator which actuates each dynamo, and which I am going to describe, in such a manner as to insert the motor in a closed circuit.

The source of electricity is at S. The same is put into communication with the earth and its two poles are connected by the wires 13 and 14, Figs. l2 and 7b, witha special switching device which is arranged in the following manner: The same is composed of a vertical shaft U, Figs. 8 and 9, capable of turning in a socket u. The vertical position of this shaft will be secured by anysuitable upper support which I have not indicated. The shaft U passes loosely through an orifice made in the IOC IIC

center of an ebonite or vulcanite bed-plate al, the periphery of which carries a series of metallic contacts 15, connected to one another andalso connected to the positive pole ofthe battery S by the wire l-lr, .and a series of metallic contacts 10 connected to each other and also to the negative pole of the battery S by the wire 13, Fig. 7b.V These metallic contacts are arranged alternately and are separated by ebonite or vulcanite parts of the same width-that is to say, that on following the periphery of the bed-plate we find contacts in the following order: a portion or section of ebonite or vulcanite, a contact 1G; a section of ebonite or vulcanite, a contact 15, the. The number of contacts 15 is consequently equal to the number of contacts 1G and to one-half of the number of the insulating portions. The shaft U then passes into openings of a larger diameter than its own, these openings being provided in the centers of `the ratchet-wheels u2 a3. The ratchet-wheel u2 is provided with teeth twice as many in number as the ratchet-wheel a3 possesses. Each ratchet-wheel is at its center provided with a hole for the passage of the shaft U, and upon the interior periphery of each of these openings three pawls t are fixed, placed at one hundred and twenty degrecs apart from one another. These pawls are by means of appropriate springs kept constantly in contact with the teeth or grooves o', formed upon that part of the surface of the axis U opposite to the two ratchet-wheels u2 and a3. It follows therefrom that if the ratchet-wheel u2 is caused to turn around one tooth the axis U will, under the action of the pawls n, turn upon itself to the extent of an arc equal to the thickness of one of the teeth or grooves thereon, since there are as many teeth or grooves arranged upon the axis U as there are teeth upon the ratchet-wheel u2. This rotary movement will be without effect upon the ratchet-wheel a3. On the other hand, if the ratchet-wheel as is caused to turn one tooth the axis Uwill be turned to the extent of an arc equal to the thickness of two teeth or grooves t', since the ratchet-wheel a3 carries half as many teeth as there are teeth or grooves upon the axis U. In this rotary movement the ratchet-wheel u2 remains unmoved. It is thus evident that according to this arrangement it is possible to cause the axis U to be turned either by the ratchetwheel u2 or by the ratchet-wheel a3, while the wheel which does not cause the movement remains unmoved during the rotation of the shaft U. Upon the exterior periphery of the ratchet-wheels its u2 the pawls n3 u2 are placed, which are kept constantly in contact with the teeth of the ratchet-wheels by means of appropriate springs. The pawl u2' is fixed to the extremity of a rod 1S connected to the plate 1.8/ pivoted at 18". One of the extremities of this plate lies in front of an electromagnet 19, Fig. 7m. The pawl a3' is likewise fixed to the extremity of a rod 17 connected to -the plate 17, which turns on a pivot 17 One of the extremities of this plate lies in front of an electromagnet 20. lVhcn a current is sent into the electromagnet 19., the plate 1S', being attracted, will turn on its axis of oscillation 18, Fig. 7b, and consequently exert a pull upon the rod 1S, and the pawl u2l iixed to the extremity of the rod 18 will cause the ratchetwheel u2 to turn to the extent of one tooth. The axis U, as I have explained hereinbefore, will itself turn under the action of the pawls t through an arc equal to the thickness of one of the teeth or grooves o',

and during this movement the wheel ug will remain unmoved. If, on the contrary, the electromagnet 20 is traversedby a current, then the plate 17 will be attracted and 'will turn about its axis of oscillation 17, thus exerting a pulling action upon the rod 17. The pawl a3 fixed to the extremity of this rod 17 will cause the wheel u3 to turn to the extent of an arc equal to the thickness of one tooth, and, as I have explained hereinbefore, the axis Uwill itself turn under the action of the pawls o through an arc equal to the thickness of two teeth, the wheel it remaining stationary during this movement. It is thus evident that it is possible to impart to the axisU displacements which are equal either to the thickness of one tooth or groove 'U' or to the thickness of two teeth or grooves o.

Upon the axis U a spring-arm V is fixed, Figs. 9 and 7 bis, which is adapted to rub upon the metallic contacts 15 and 16 and upon the insulating parts which separate these metallic contacts. The number of metallic contacts 15 and 16 and of insulating parts which separate these contacts is exactly equal to the number of teeth or grooves i1 of the axis U and likewise to the numberof teeth arranged upon the outer periphery of the ratchet-wheel u2. It is thus evident that-if we suppose for a moment the arm V to be placed upon one of, the contacts l5, as indicatedin Fig. 7b, and if we send a current into the electromagnet QO-the axis U will, under the action of the ratchet wheel a3, turn through an arc which is equal to the thickness of two teeth or grooves u and the arm V, which was pressing upon the contact 15, will now press upon the following contact 16 after springing over the insulating part which separates these two consecutive contacts. If, on the contrary, Vwe send a current into the electromagnet 19 while the arm V is upon the contact 15, as indicated in Fig. 7b, the axis U will, under the action of the ratchet-wheel fil/2, turn through an are equal to the thickness of a tooth or groove i2', and consequently thel arm V will become placed upon the insulating part which separates the contact 15 upon which itwas resting from the contact 16 which immediately follows it. The arm V, which is insulated from the whole switching device, is connected by the wire 21 to the electromotor g. If thus the arm V rests upon one of the insulating parts which separate theme- IOO IIO

tallic contacts and 16, no current will arrive at the electromotor. If, on the contrary, this metallic arm V rests upon a contact 15, a positive current coming from the battery S will pass through the wire 14: to the contact 15 upon which the arm rests. The current will then pass through the arm V and the wire 21 into the electromotor, which latter will revolve, for instance, from the leftto the right. If instead of lying upon one of the contacts 15 the arm V rests upon the contact 16, a negative currentwill pass from the battery through the wire 13 into the contact 1G, upon which the arm rests, and thence through the arm V and the wire 21 to the electromotor g. This latter will thus revolve in the opposite direction-that is to say, from the right toward the left. The operation of the motor-switch is thus simply obtained by sending currents either into the electromagnet 19 or into the electromagnet 20. This sending of currents is effected automatically at the desired moment, as hereinafter described, by the movement of the carriage.

The electromagnet 19 is connected on the one hand to the local battery 22 and on the other hand to the contacts L andjl, Fig. 2, through the wire 30.

The electromagnet 2O is connected on the one hand to the local battery 22 and on the other hand to the contact L, Figs. 2 and This, by the wire 23. The battery 22 is itself connected by the wire 27, Fig. 2, to the band or strip N parallel with the rails el.

Such is the complete description of the mechanisms which constitute each carriage corresponding to the apparatus of a subscriber, all carriages being arranged either at a district station or at the central station.

As hereinbefore stated,there passes from the switch A the wire 2, which terminates at the central station in the metallic band or strip which passes beneath the plates X and Y and which has, in each of these plates, a metallic Contact having the abscissa and the ordinate corresponding to those connected to the subscribers apparatus in question. On theother hand, as has been likewise stated, the beam R is connected to the plate X by the wire 10 and the beam R is connected to the plate Y by the wire 11.

Before describing the complete function of the apparatus there remains to bel mentioned the new arrangement which I have applied to the plates X and Y, and which were already provided in the apparatus described in the aforesaid specification. There is nothing altered in these plates X and Y except the arrangement of the special switching device 2S--that is to say, that the plates are always provided with a double carriage E1 E2 capable of being displaced in two perpendicular directions, and which are caused to follow the line of the abscisszrJ by the passage of the positive currents and to follow the line of the ordinates by the passage of the negative currents. The diierent contacts on the plate X for producing these displacements in the two directions and for stopping at the desired moment the electromagnets of the'carriage remain the same, and these different mechanisms are always connected in the same manner to the line-wires 10 and 11,which, instead of terminating, as in my former apparatus, at the subscribers instruments, terminate actually at the beams R R. As regards the switching device 2S, the same is arranged in the following manner: It is composed of an electromagnet E3, Fig. 12,whicl1, when traversed by a current, causes a plate 31, Figs. 10 and 11, to be attracted, which plate carries an arm 32, at the extremity of which a pawl 33 is fixed, which can act upon the vratchetwheel 34, keyed upon the axle 35.

When the attraction of the plate 31 takes place, the arm 32 while descending causes the pawl to turn the wheel 34E in the direction in which the hands of a clock: travel upon the dial, Fig. 11. A stop pawl forming a brake, regulates the rotary motion of the wheel 34E in such a manner that the same will turn through a distance equal to one tooth at each attraction of the plate 3l.

Upon the axis 35, set in movement by the ratchet-wheel 34, are fixed:

First. A metal wheel 3G, Fig. 10, insulated from the axis 35 and provided with four projections Zl Z2 Z8 Z4, arranged at the extremities of two diameters at right angles to one another.

Second. An ebonite or vulcanite wheel 37, which carries four metallic rods S1 s2 S3 s4 forming two groups of two parallel rods, each group being perpendicular to the other. The extremities of these rods, which are bent down, can be displaced upon a series of contacts which are hereinafter described. The same is the case, on the other hand,with the projections Z1 Z2 Z3 Z4, firmly secured to the wheel 3G, it being well understood that the extremities of the metal rods of the wheel 37 cannot touch the contacts upon which the projections Z1 Z2 Z3 Z4 are displaced, and that,vice versa, the projections Z1 Z2 Z3 ZAl cannot touch the contacts upon which the extremities of the said metal rods are displaced.

Third. The ratchet-wheel 3i, of which I have spoken hereinbefore. This wheel is iixed directly upon the axis 35 without the interposition of insulating material. The same is provided with eight teeth.

Finally, right above the ratchet-wheel 3l, but not in contact therewith, a disk 38 is arranged, the periphery of which is divided into sixteen parts, of which eight are metallic and eight of insulating material, the metallic parts alternating with the parts of insulating material. Upon the periphery of this wheel, at the extremities of one and the same diameter, two iixed brushes 39 and 40 make contact, one of which-namely, the brush 39-is connected to the line-wire which sets the relay electromagnet 29, Fig. 12, into communication with the corresponding beam7 and the other of which,

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40, is connected by the wire 4l to the negative pole of the local battery, as in my patented apparatus.

When the ratchet-wheel 34: is at rest, the two brushes 39 and 40 press upon insulating parts of the disk 3S, but when the ratchetwheel turns the distance of one tooth, thereby carrying with it the disk 3S, the brushes then press during this rotary motion upon metal parts of the disk in order to arrive subsequently again upon insulating parts.

Having thus described the different mechanisms which constitute my new telephone system, I will nonT proceed to describe the operation, while giving likewise the details of all connections established between the different mechanisms of which my system is composed. In order to facilitate this description I will refer to Figs.v l2 and I2, in which I have represented the posts or apparatus of four subscribers w my z. Each of these subscribers has his separate carriage or wagon, and these four carriages or wagons can be displaced above the two beams R R', one of which acts upon the plate X and the other upon the plate Y.

In describing` the operation of the apparatus, in order to distinguish the mechanisms which belong to the subscriber from those belonging to other subscribers, I shall add to each reference-letter the letter X whenever I speak of a part or mechanism belonging to the apparatus of the subscriber 5o, and analogous I shall add the letter y to each refer-` ence-letter, designating a piece or a mechanism appertainin g to the apparatus of the subscriber y, and so on; but, as for the sake of facilitating the explanation, I shall be likewise compelled, when describing the operation of the apparatus, to refer to the detail figures which I have previously used for eX- plaining the arrangements adopted in my apparatus, which iigures are not marked by the additional indications X, y,7 or z, or w. It is necessary to make it understood once and for all that the signs X, y, or 2, or w will exclusively serve for the description, the drawings having of course the same letters, but without the signs X, (37,77 Ol1 CZ?) (C 7.77

Let us suppose that the subscriber wishes to enter into conversation with the subscriber The subscriber will press upon the knob V in his plate, which knob was already provided in the apparatus described in the aforesaid speci'ication, and while pressing upon this knob the subscriber a; sends, as we have seen, a series of positive currents, which pass through the line-wire and thus to the plates b and 62X of the switch AX, which latter is in the resting position-that is to say, in the position shown in Fig. 7. The positive current arriving in ZJ will have no action at all, because this plate is insulated; but the current also arrives in the plate 222x, passes into the blade a, and through the wire 5x, and arrives in the metal band or strip FX, parallel to the rails for the carriage upon which the electromagnet EX is mounted. From this band or strip the current can take two directions. It can either pass through the platform ex, through the blade P4", or it can traverse the electromagnet EX, through the blade fx, since the two blades fx and PX are in contact with the earth, the current entering this electromagnet through the blade fX will be enabled to pass through the earth to the subscrbers apparatus. Thus the circuit of the electromagnet Ex is completed, and this electromagnet attracts the plate hx. Vhile turning aronndits axis of oscillation h, the plate hx, from which the blade j'x is suspended, will force this blade to rub against the contact j, Fig. 3.

Let us now see what is the effect of the contact established between the metal piece j and the blade j'x. This blade is, as is hereinbefore described, and as is indicated in Fig. 3, connected through the wire 9x to the blade "m", which rubs upon the metallic band or strip NX, Fig. 2, which latter is connected by the wire 27 to the battery 22, Fig. 12. .On the other hand, the metal piece j is connected by the wire 30X to the electromagnet l9,which latter is on its part connected to the battery 22K by the wire 31X. At the moment that the blade jx and the metal piece j make contact with one another the circuit of the electromagnet 19X is closed. This electromagnet is thus traversed by a current, and the ratchetwheel MX is turned to the extent of one tooth under the action of the pawl ugx. The arm Vx, which was previously resting upon an insulating portion of the Wheel u, is placed in contact with the metallic part 15x, which follows immediately after the insulating part upon which the arm was previously resting before,and, as we have seen hereinbefore, this arm then completes the circuit of the motor g, which is traversed by a positive current, which arrives from the battery Sx and passes through the arm VX, the wire 21X, and the motor. This latter consequently revolves from the left to the right and causes the screw gX to turn, the effect of which, as I have hereinbefore explained, is to produce the displacement of the carriage in a forward direction, as indicated by the arrow in Fig. l2.

As soon as the carriage has been displaced to an amount equal to the length of the inclined planes IX, upon which the prolongations t" of the hook h3 were resting, the said hook falls and holds the plate hx applied against the electromagnet EX, this taking place before the blade fx has left the wielening of the plate FX, through which the electromagnet receives the current. The car- IOO IIO

riage therefore continues its displacing movement under the action of the motor-screw gx, and a moment will be arrived at when the cross-rail mx of the frame h x comes in contact with the beam R. As the carriage cannot become lifted upon its rails, and as the same is compelled to advance under the action of the motor-screw gx, it is the beam R which becomes lowered, while the frame Mx turns around its axis of oscillation m'x. In this rotary movement of the frame around its hinge m'x the blade Kx fixed upon this frame rubs upon the metallic part Lx. Let us now examine the effect caused by the contact of the blade Kx with the metallic piece Lx, which is connected to the wire 30x of the circuit of the electromagnet 19x, and on the other hand the blade Kx is connected by the wire 9x to the blade mx, which rubs upon the band Nx.

At the moment of the contact of the blade Kx with the piece Lx the circuit of the electromagnet 19x is closed, and, as previously, the arm Vx of the switch will be actuated and will place itself upon that insulating part which follows after the contact 15x upon which it previously rested. By this movement of the arm Vx the circuit of the dynamo glx is opened, it stops, and consequently the carriage or wagon Ex likewise stops while maintaining' the beam R depressed by the metallic frame Mx. The positive current sent by the subscriber when pressing the knob V1 is thus enabled to pass now through the band or strip Fx, the blade Px, the platform ex, the frame Mx into the metallic part of the beam R and thence through the wire 10 into the plate X, and this positive current will not be able to follow any other course. If at the moment of the passage of the carriage over the beam R, this latter were occupied-that is to say, lowered by the carriage of the subscriber w, for instance-the carriage Ex would have continued its course, since the blade Kx would not have been enabled to rub upon the contact Lx. In continuing its course the carriage would have arrived above the beam R', with which it would have been thrown in con tact if this beam R' were free, and what we have said hereinbefore from the point of View of the communications as regards the beam R evidently also applies to the beam R', only the subscriberfc, instead of utilizing` the plate X for obtaining the communication with the subscriber e' would have utilized the plate Y, since this latter is connected to the beam R'. If at the moment of the passage of the carriage Ex over the beam R', this latter is in the depressed position-that is to say, occupied by another subscriber-the carriage Excontinues its course until the blade Kx rubs upon the metallic contact L'x placed at the extrem ity of the rails or path of the carriage Ex.

Let us examine the effect produced by the contact of the blade Kx with the plate L'x. This plate is connected by the wire 23x to the electromagnet 20x, which latter is itself connected by the wire 31x to the battery 22x,

which terminates through the wire 27x in the band or strip Nx upon which the blade mx rubs, which latter is itself connected to the blade Kx, as we have already seen. The circuit of the electromagnet 29x is thus completed by the contact of the blade Kx with the plate L'x. This lelectromagnet attracts the pawl tt'x, and the arm Vx, which was resting upon a metallic contact 15x, will place itself upon the following metallic contact 16x after having passed, without stoppage, the insulating part which separates the two.contacts l5x and 16x. The rotary direction of the motor is thus abruptly changed, and the screw gx, revolving` in the contrary sense, forces the carriage to return. Vhen arriving near the starting-point of the carriage the prolongations tx, Fig. 3, of the hook hx, which latter maintained the plate h4 against the electromagnet Ex, rise upon the inclined planes Ix, and the hook tgx rises, thus leav ing the plate hx to itself. This plate, under the action of the spring Wx, Figs. 3 and 6, is brought back against the support Hx while turning around its pivot hlx. During this movement of the plate the bladej'x, which is iiXed to the plate by the rod jx, rubs against the metallic contact jlx, the effect of which, as before described, is to complete the circuit of the electromagnet 19x, which latter is thus traversed by a current and actuates the ratchet-wheel u2". The arm Vx of the commutator or switch which was previously in contact with a metallic contact 16x will place itself upon the insulating part which follows this contact. The motor will thus be stopped, as well as the carriage or wagon, which will thus have arrived at its startingpoint.

As is evident from the preceding, there are three effects possible when the subscriber x sends a positive current through the line-wire for displacing the carriage Ex. First, the carriage Ex is hooked onto the beam R and stopped; second, the carriage Ex is hooked onto the beam R' and is stopped; third, the carriage Ex is not hooked onto any beam and returns rearwardly to its startin g-point,where it stops.

Let us suppose in the continuation of the description of the operation of our apparatus that this is the first effect that has taken place-namely, that the carriage or wagon Ex has become hooked onto the beam R.

In the plate X the positive currents will have the effect, as I have explained with regard to the apparatus described in the aforesaid specification, to displace the double carriage according to the line of the abscissa by sending to the subscribers apparatus negative controlling-currents, which will cause iigures to appear in the opening provided above the knob Vx. Vhen the figure which will appear to the eyes of the subscriber is equal to that which corresponds to the abscissa of the subscriber with whom he wishes to be set in communication, and which, in

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the example shown, has the abscissa 3, he will stop pressing the button V, and by acting upon the button V2X he will send a series of negative currents, the effect of which will be to displace the carriage E2X along the line of the ordinates, and the effect of this displacement will be to send to the subscribers apparatus positive controlling-currents, which will cause figures to appear in the opening provided above the knob VQX. lVhen the figure appearing to the eyes of the subscriber is that which corresponds to the ordinate of that subscriber with whom he wishes to enter into communication he will stop pressing` the button Vx and will then press upon the button V3X. The effect of pressure on this knob V3X in the present apparatus is entirely different from that which took place in the ap paratus described in the aforesaid specification, and I will now proceed to describe it in detail.

The pressure exerted by the finger of the subscriber upon the knob V3X has for its object to send, as hereinbefore stated, one single positive current into the plate X. This positive current cannot, for the saine reason which I have indicated in my prior patent, act upon the electromagnets of the carriages E1 E2, but it can act upon the electromagnet ES, which controls the commutator 28. Under the action of this positive current,which traverses the electromagnet E3, the ratchetwheel 34 turns through the distance of one tooth, thereby causing to turn with it the axis 85, Figs. lO and ll, and consequently the wheel 36, as well as the wheel 37, which carries the switches S1 S2 s3 s4, arranged in perpendicular pairs, will likewise turn at the same time as the shaft Let us now consider the effect of this rotation corresponding to one eighth of a revolution, since the ratchet-wheel has only eight teeth. The projecting parts Zl and Zs of the wheel 36, which were at first in contact with the terminals 30 and 4l, respectively, come into contact with the terminals 42 and 43, the eect of which, as in the apparatus described in my prior patent, is to disconnect the electromagnet of the carriage E2. On the other hand, the terminal 42 is connected to the style S1, which is displaceable upon the contacts of the plate, and the terminal 43 is connected to the line 11. Moreover, the rods of the wheel 37, during this former displacement, will press, on the one hand, upon the contacts 7l and 70, and, on the other hand, upon the metallic contacts 74 and 75. The contacts 7l and 70 are connected to the so lenoid which surrounds the style Sl, whereas the contacts 74 and 7 5 are connected, onenamely, the metal contact 74, Figs. 10 and ll-to the positive pole of the battery, and the other-namely, the contact 75-to the negative pole of the battery. A current thus traverses the solenoid which surrounds the style S1, and the action of this current causes uthe style S1 to be applied against the contact above which the said style lies, and which, in the example shown in the drawings, is the contact of the subscriber It follows therefrom that the first rotation of the coinlnutator 2S has this effect: to disconnect the electromagnet of 'the carriage E2, to put the style in communication with the beam, which com munication had been lost by the latter since the first displacement of the double carriage along the line of the abscissae, and to strongly apply the style against the contact of the instrument of the subscriber e. This rotation has, moreover, the effect of sendinganegative controlling-current to the instrument of the subscriber o through the wheel 38 and the brushes 40 and This controlling-current arrives at the subscribers instrument and traverses the electromagnet EGX, the circuit of which is completed by the contact of the finger yasx and of the platen. Thereby the disk or wheel J X which is actuated by the electro* magnet turns one-fourth of a revolution. The said disk or wheel, as shown and described in my patent aforesaid, carries near its peri pliery the words Repos, (rest,) Sonnez, (ring,) which repeat twice in the same succession. At the beginning, before a pressure upon the button V3X is exerted, it is the word Repos (rest) which became visible to the eyes of the subscriber through the opening in his apparatus opposite the disk or wheel JX; but as soon as this disk or wheel has turned one-fourth of a revolution under the action of the electromagnet ESX, owing to the negative controlling-current produced by the rotation of the disk 38, the word Sonnez (ring) appears to the eyes of the subscriber, who is thus automatically informed about the position of the mechanisms of the plate X. He follows the indication and presses upon the ringing-knob, which sends a series of negative currents. These negative currents, following the way which we have indicated, arrive at the beam R and pass through the wire l0, the terminal 48, the projection Zi, the projection Z3, the terminal 42, and arrive at the style S1. These currents thence pass into the contact of the subscriber z, upon which the style rests, and through the wire 2 arrive at the terminals b and UY of the switch A. This negative current cannot pass through If, which is insulated, but passes through Z2 into the electromagnet CZ, which is connected to the earth. The current thus returns through the earth tothe subscribers instrument and the circuit of the electromagnet CZ is completed. This electromagnet is thus traversed by a current and attracts the plate D while turning the rod a of the switch, so as to bring the blades d'7 and al respectively into contact with the terminals Zf'z b1. The negative currents constantly sent by the subscriber a' now pass to the switch AZ, no longer through the terminal ZJ, which has been insulated by the rotation of the rod o", but through the terminal 11', upon which the blade af actually rests. The negative our IIO rents passing through the blade @"1 pass through the wire 7Z into the blade a1 and through the terminal Z911 upon which the blade blade a1" rests. The negative currents arrive at the instrument of subscriber e', Where they cause the bell to ring. The subscriber e, thus informed by the bell that he is called to the instrument, applies the telephone to his ears and can instantly enter into communication with. the subscriber Qc who has called him.

Vhen the conversation is finished, the two subscribers and a, who were engaged in conversation, both press the knob V'1 of their respective apparatus.

It is evident that the subscribers instrument might be so combined that the action upon the knob V1 would take place automatically when the telephone is rehooked onto the instrument.

Let us now consider the eifect produced upon the mechanisms of the apparatus by the action of the knob V4" of the apparatus of the subscriber .2'. The positive current, which, as we have seen, is produced by pressing this knob, since the mechanisms of the knob V1 are identical to those of the knob V3, passes through the wire 1V' and arrives at the terminal 017* and through the blade a1" in contact with the terminal b1. The current then arrives in the electromagnet CZ, the circuit of which is completed through the earth. This electromagnet attracts the plate D1', the effect of which is to return the rod a into its initial position, thus returning all the mechanisms of the instrument of the subscriber .e into the position which they have to occupy at the commencement of each communication-that is to say, returning all these mechanisms to what we might term their Zero7 or normal positions.

We are now going to examine the effect produced by the positive current sent by the subscriber x when ressinor the knob V4 of his instrument. This current arrives in the plate X, as previously, through the band or strip FX, t-he blade P", the frame or support e, the beam R and the wire 10. This current traverses the electromagnet-relay 29 which then completes the circuit of the electromagnet E3. This latter is traversed by a positive current, which causes the attraction of the plate 3l, and the pawl 33 causes the ratchet-wheel to turn through the distance of one tooth, Figs. l0 and 1]. The wheels 36 and 37 follow this movement and, consequently, effect a second rotary motion to the extent of oneeighth of a revolution, the effect of which we will now consider:

Second. The rotary movement of one-eighth of a revolution of the wheel 37 forces the two metallic rods s1 s2 to first rub upon the two blocks or contacts 72 73 by one of their extremities, and upon the contacts 75 and 76 by the other extremity. Now the blocks 7 2 and 7 3 are connected to the solenoid which surrounds the style S1, and the metallic contact 75 is connected to the negative pole of the battery, Fig. ll, whereas the contact 76 is connected to the positive pole. It follows, therefore, that at the moment of the passage of the rods s1 s2 over the blocks or contacts 72 73, and over the contacts 75 and 76, the solenoid which surrounds the style S1 is traversed by a current in contrary direction with regard to that which had traversed it for applying the style against the contact of the subscriber z. The style is thus lifted and takes up its place at that height which it normally occupies when it is to be displaced above the contacts of the plate X.

Vhen continuing their rotary motion the rods s1 32 rub on the one hand upon the blocks or contacts 77 and 7 S and on the other hand upon the contact 76. The blocks or contacts 77 and 7 S are connected to the electromagnets 79 and 80, Fig. l2, serving for the return of the carriages E1 E2, and the contact 76 is connected to the positive pole, and as the electromagnets 79 and SO are connected to the negative pole of the battery a current is established which traverses the electromagnets 79 and SO, and the carriages E1 and E2 are returned to their starting-point. On continuing their rotary movement the rods .s1 s2 pass over the contacts 7 7 and 7 S', which follow the contacts 77 and 7 8, but which are insulated therefrom, Figs. ll and l2, and over the contact 76. Now the contact 77 is connected by the wire Sl to the electromagnet XV, placed at the one extremity of the beam R, and the contact 7 S is connected by the wire S2 to the electromagnet XV', placed at the other extremity of the beam R. At the moment when the rods s1 and S2 pass over the contacts 7 7 7 8 and 76 a current traverses the electromagnets XV and VV, the circuits of which are completed. This current, which traverses the electromagnets W and V, produces the upward attraction of the beam R, and this latter while being raised forces back the carriage Ex very slightly, but to a sufficient extent so that the blade Kx will touch the contact LX, which, as we before described, completes the circuit of the electromagnet 19x of the commutator of the motor gh'. The arm VX, which was resting upon an insulting part, is placed upon the following metal contact, which is of necessity one of the metal contacts 16x, producing the rearward motion of the carriage, since before its stationary period on the beam R the carriage Ex was moving forward, the arm VX touching a metal contact 15x causing the forward movement, and we have seen that upon the plate u of the switch or commutator the metal parts are arranged in the following succes- IOO IIO

sion: first, a metallic part 15x, connected to the positive pole of the battery, (forward movement;) second, an insulating part, (stoppingg) third, a metal part 16x, connected to the negative pole of the battery, (rearward movement 5) fourth, an insulating part, (stopping,) tc. The carriage Ex thus returns rearwardly until it has arrived at the extremity of its course, where, as we know, it stops, owing to the contact of the rod jx and of the terminal j, which contact, again completes the circuit of the electromagnet 19x. It follows therefrom that all the mechanisms of the plate X, also those of the carriage of the subscriber c and those of the carriage of the subscriber s,

have now returned to their starting-point.V

All the parts of the apparatus are therefore now at their zero or initial position.

There remains to be examined the effect produced by the negative controlling-current in the commutator 2S at the moment of the contact of the brushes 39 and 4:0 upon metallic parts of the wheel 38. This negative controlling-current arrives at the instrument of the subscriber and traverses the electromagnet EGX. The wheel Ix thus turns one-quarter of a revolution and the word Repos (rest) appears opposite the openin g provided above the wheel IX. It is thus evident that after the pressure has been exerted by the two subscribers a: e' upon the knobs V4, the whole is brought back to the zero position and the mechanisms are ready for a newconversation. The same phenomena would take place in the same succession if instead of entering into communication with the subscriber .e the subscriber m had entered into communication with another subscriber, and if instead of the carriage hX having become hooked onto the beam R it had been hooked onto the beam R.

In order to prevent any subscriber from unduly monopolizing a beam, I provide a counting apparatus of any suitable kind at the e, tremity of each of these organs. This counting apparatus is actuated by the lowering of the beam, and at the expiration of a given lapse of time automatically completes the circuit of the electromagnets W W for the return.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is- 1. In a switchboard system for automatic intercommunication, the combination with a number of subscribers lines, of carriages one for connection with each of said lines, switchboards or contact-plates at the central station of less numberthan the number of subscribers, each switchboard having contacts for all of the subscribers lines, devices-such as beamsin electrical connection with the switchboards and with which the carriages are adapted to make contact to complete the circuit to the switchboard, substantially as described.

2. In a switchboard system for automatic intercommunication, the combination with a number of subscribers lines, of carriages to which the terminals of said lines are respectively connected, switchboards or contactplates at the central station of less number than the number of subscribers, beams corresponding to and electrically connected with the switchboards respectively, said beams lying normally in the path of the carriages and adapted upon contact of one carriage therewith to be moved out of the path of the others, and means controlled from each subscribers station for actuating his correspon ding carriage, substantially as described..

3. In a switchboard system for automatic intercommunication, the combination with a number of subscribers lines, of carriages to which the terminals of said lines are respectively connected, switchboards or contactplates at the central station of less number than the number of subscribers, beams corresponding to and electrically connected with the switchboards respectively, said beams lying normally in the path of the carriages and each adapted upon contact of one carriage therewith to be moved out of the path of the others, means controlled from each subscribers station for actuating his corresponding carriage, and means for automatically returning the carriages to their startingpoint when all of the beams have been moved out of the path thereof, substantially as described.

4. In a switchboard` system for automatic intercommunication, the combination with a number of subscribers lines, of carriages to which the terminals of said lines are respectively connected, switchboards or contactplates at the central station, one corresponding to a number of the subscribers, beams corresponding in number to and electrically connected with the switchboard s respectively, said beams lying normally in the path of the carriages and being adapted upon contact with one carriage to be moved out of the path of the others, a motor for driving each carriage connected in a local circuit, a switching device or commutator for closing said circuit, an electromagnet in another circuit for actuating said switching device, an electromagnet on the carriage adapted when energized to close said latter circuit, and means at the subscribers station for closing a circuit through the electromagnet on the carriage, substantially as and for the purpose set forth.

5. In a switchboard system for automatic intercommunication, the combination with a number of subscribers lines, of carriages to which the terminals of said lines are respectively connected, switchboards or contactplates at the central station, one corresponding to a number of subscribers,beams corresponding in number to and electrically connected with the switchboards respectively, said beams lying normally in the path of the carriages and being adapted upon contact IOO IIO

with one carriage to be moved out of the path of the others, a motor for driving each carriage connected in a local circuit, a switching device or commutator for closing said circuit, an electromagnet in another circuit for actuating said switching device, an electromagnet on the carriage adapted when energized to close said latter circuit, means at the subscribers station for closing a circuit through the electromagnet on the carriage, and contacts, connected with the circuit for actuating the switching device, in proximity with the beams and with which the carriages are adapted to make contact, when engaged by the beam, to close the circuit to actuate the switching device and open the m otor-circuit to stop the carriage, substantially as described.

6. In a system. of the kind described, the combination with a subscribers line-wire, a carriage therefor, and beams connected rcspectively with the switchboards and with which the carriage is adapted to engage, of a motor for moving said carriage in opposite directions accordingr to the direction of the current energizing the same, a battery for supplying the current, a switching device interposed between said battery and motor for connecting the circuit through the latter in opposite directions, and for breaking the same, said device consisting of a contact-arm connected with the motor, and a series of alternatelyarranged conducting and non conducting plates with which the arm is adapted to make contact, the conducting-plates being alternately connected respectively with the positive and negative poles of the battery, and electromagnetic devices controlled from suitable mechanisms on the carriage for moving the arm over the contact-plates, substantially as described.

7. In a system of the kind described, the combination with a subscribers apparatus and carriage corresponding thereto, of a switch comprising a bar carrying two contactblades at each end, the blades at one side being respectively connected with electromagnets for operating the switch, and one of said blades being also connected with the diagonally-opposite blade at the other side of the bar, and the remaining `blade on said latter side being suitably connected with the carriage, and two fixed contacts with which the blades are to respectively engage in proximity to each end of the bar, those contacts at one end being connected with the subscribers line and those at the other end to the subscribers7 contacts on the switchboard at the central station, substantially as and for the purpose set forth.

ln testimony whereof I have signed this speciiication in the presence of two subscribing witnesses. u

MOISE FREUDENBERG.

XVitncsses:

CLYDE Snnorsninn, EDWARD BARBURY.

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