US673039A - Telephone system and apparatus therefor. - Google Patents

Description

no. 673,039. Pafntd Apr. 3o, |901.

. A. T. n. manson.

TELEPHUNE SYSTEM AND APPARATUS THEREFOB.

(.ppumionmed occ. s, 1899.)

(No Ilodal.)

6 Shoots-Sheet l.

TH: nonms Evans cc. miam-uma. wumo'row nv c, 1

M. 673.039. ranma Apr. 3o, 19m. A. T. n. manson.

TELEPHUNE SYSTEM AND APPARATUS THEREFOB.

(Application Med Qct. 9, 1899.)

m: Npnms PErzRs co.. PHofaLn'no., wAsHmmou: D. c.

No. 673,639. 4 Patented Apr. 30, I90l.

` A. T. M. THOMSON. l

TELEPHONE SYSTEM AND APPARATUS THEREFOB.

' (Appumiqn med ore. 9, 189s.) (Ilo Modal.) l 6 Sheets-Sheet 3.

No. 673,039. Patented Apr. 30, 190|.

A. T. I. THOMSUN. TELEPHONE SYSTEM AND APPARATUS THEBEFUR.)

l(lpplimtiml led Oct. 9, 1899.)

6 Shoots-Shoot 4.

No.' 673,039. Patented Apr. 30,1901.

A. T. n. Thomson.

TELEPHONE SYSTEU AND APPARATUS THEREFOR.

(Application 'Bled Oct. 9, 1890.) (lo INM.)- 6 Sheets-Sheet B.

No. 673,039. Patent Apr. 3u, mul.

A. T. n. THousou. TELEPHONE SYSTEH AND APPARATUS THEREFUR.

v (Aimnmim and oeck n, 1an.)

(No Iodel.)

El l 15u/mlm:

Tn: Nonnfs PETERS ca. vuoraumo.. WASHINGTON. D. c.

UNITED STATESi PATENT OFFICE.

ARTHUR`THOMASMILNOR rFHOMSON, OF EAST DULWICH, ENGLAND.

TELEPHONESYSTEM ANfo APPARATUS THEREFOR.

SPECIFICATION forming part of Letters Patent No. 673,039, dated April 30, 1901.

Application filed October 9. 1899. Serial No. 733.069. (No model.)

full, clear, and exact description of the in- Vention, such as will enable others skilled in the art to which it appertains to make and use the same. Y

This invention relates to improvements in telephone systems and in apparatus therefor.

The invention is more especially designed With a View to simplify, facilitate, expedite, and lessen the cost of working of complex telephone connections such as are required for an eiticient service in large towns-that is to say, wherever' the number of subscribers or users is very large, and consequently the system as a whole very busy; but of course it is applicable to any lesser demands.

Themain objects of the invention are, first, to do away with the verbal intercommunication between the subscribers or users and the operators at the exchange now necessary in order for one subscriber to be put into comm unication with another or one exchange with another, as the casegmay be, and thus avoid all the attendant inconveniences and substitute therefor what maybe called a secret service, because the operators at the exchange have no means by which to overhear the conversation between two users, and, second, to do away entirely with the present multiple switchboard and so simplify and. cheapen the outfit and expedite the operating at the exchange and cost of operating and maintaining the system and service.

The invention consists, then, in certain apparatus and in the group or combination of these apparatus comprising signaling, printing, and indicating devices and in the coinbination of this group o f apparatus with ordinary or well-known telephonie instruments and connections to form a complete novel telephonie system.

Before describing the new group of apparatus itself it may be well to mention here, in order to render what follows the more intelligible, that part ot' this apparatus is located at the subscribers end ot the line, and is substituted for the present ringing-up or signaltransmitting apparatus of an ordinary telephone set, andypart at the exchange, that the operators at the exchange in this system are not provided with telephone receivers and transmitters, and that the source of the electric or magnetic current employed for automatically signaling, indicating, recording, and clearing the connections is situated preferably at the exchange; but as in some cases it may be more desirable to locate it at the user-s end of the line it is to be understood that I do not bind myself in this respect.

I will now proceed to describe my invention in detail, reference being had to the accompanying drawings, illustrating same, and in which- Figure 1 is a rear elevation of one form of the. indicator-switch, telephone apparatus, and connections at the subscribers or users end of the line. Figs. 2, 3, and-tare respectively a cross-section and side and front elevations ot' the gravity latent switch, Fig. 1. Fig. 5 is a plan of the printer used to print the names of exchanges and shows how it is connected with the special switch. Fig. 6 is an elevation of the special switch at the exchange consisting ot' an oscillatory springjack and plug, the latter being shown insei-ted and in the position for operating a call. lts connections with the exchange-printer, line-wires, and special indicator are also shown. Fig. 7 is the specialoscillatory indicator which distinguishes a call on the local exchange from one for a distant' exchange, its connections with the jack at the switchingboard, the special switch, the exchangeprinter, and the line-wires. Fig. 8 is va section of the exchange-printer, taken on the line 8 S of Fig. 5. Fig. 9 is a diagrammatic plan of the latent switch L S, the engaged or busy signal E S, the exchange-printer- E P,

the special jack-switch J S, the special indicater S I, and their connections. 1l are respectively an end view and front elevation of the special indicatorS I. Fig. l2 is a diagrammatic plan of the numerical printer N P, clearing-relays C R, visualsignals V S, and their connections. Fig. 13 is a diagram of the entire system, showing the apparatus and connections necessary for a complete call Figs. 10 and.

from one subscriber to another, the gravity form of latent switch being employed, L S being the latent switches, E S the engaged signals, C B the call-bells, E P the exchangeprinter, N P the numerical printer, J S the special jack-switches, S I the special compound indicator, C R the clearing-relays, and V S the visual signals.

Latent swt'tch- Gravity type- The instrument or apparatus substituted for the usual telephone-call set or outiit at the subscribers office or end of the line is an indicator latent switch, and is hereinafter for brevity referred to as the latent switch. This switch is shown in detail in Figs. 1, 2, 3, and 4 and is composed substantially as follows: On a base or foundation plate 1 is mounted in a bracket 2 an electromagnet 3, one terminal of which is electrically connected by means of the wire 3', insulated make-andbreak contact 32'33, and line-wire L', or, on the other hand, by the wire 3, insulated makeand-break contact 34 35, and line-wire L2 with aspecial switch situated at the exchange, preferably near the originating operator-that is, the operator who first receives the call. This special switch will be described in its turn later on; but I may here brieliy remark that it is preferably of the spring-jack and plug type and is shown in detail at J S in Fig. 6 and in diagrammatic form in combination in other figures, the line-wires L L2 terminating at the exchange in the plug J P of the said switch. The other terminal of the magnet 3 is connected, as indicated, by the plate E to earth. Mounted also upon the base-plate 1 at the back thereof are iive plates 4, 5, 6, 7, and 8, bearing a number of raised contacts, respectively 4', 5, 6', 7', and 8, in or upon their exposed or rear surface, the said contacts being advantageously formed as ridges or ribs produced by merely iiutiug, grooving, or corrugating the plates, but may be produced in any other suitable way. These plates are mounted upon the foundation-plate in such a manner as to be slidable thereon transversely in a substantially horizontal direction, the mechanism by which they are moved being advantageously formed, as shown ,consisting of a spindle 9, rotatably mounted in the base-plate 1, a toothed pinion 10, fast on the rear end of said spindle, a rack 11, formed in or secured fast to the front face of the movable contactplates and always in engagement with said pinion, and a milled thumb-nut 12, screwed fast on the outeror frontend of the spindle 9, so that turning this nut in either direction causes a corresljronding sliding movement of the contact-plates by reason of the pinion 10 engaging in the teeth of the rack 11, which it moves, the contact-plates sliding between the foundation-plate 1 and guides 13.

The contacts on the plate 4 represent the various exchanges inthe town or city area and also, where necessary, special services, such as trun k or long-distance calls-1.l1atis, to exchanges in towns or cities outside the area of the others-telegraph-oice, postofiice, special-messenger service, and also certain special officials in such offices, such as clerk in charge, &c. The contacts on plates 5, 6, 7, and Srepresent, respectively, the thousand, hundreds, tens, and units of the subscribers or users numbers. The movable plates are all in electrical connection with the metallic foundation-plate 1, wires 43 serving to emphasize this connection.

It will be observed in Fig. 1 that the plates in question are cut olf obliquely at their outer ends, terminating at their upper edges in a point, while the edge of the foundationplate is cut squarely or at right angles to the top and bottom edges of the movable plates. The object of this is to enable the exposure beyond the edge of the foundationplate of a single one or any number of the contacts at will by simply turning the thumbnut in the outward direction, so as to advance the con tact-plate to the desired extent. In order to inform the user from the outside of the apparatus as to how much to advance the plates so as to expose the right number of contacts to give a call correctly, disk wheels or dials 14, having notches 15 in their peripheries, and figures, letters, or other signs or combinations of figures, letters, or signs on their outer faces, preferably near to the periphery, may be iixed on the spindles 9 ontside in front of the foundation-plate 1 between it and the thumb-nuts or knobs 12. The said numerals or other characters or signs correspond to the number ot' contacts exposed, and as these contacts, as above stated, represent. the different exchanges,spe cial services, and orders of numerals constituting the subscribers numbers the user by simply turning the knobs or thumb-nuts 12 can set these dials to any exchange and number on that exchange desired.

In the construction shown in the drawings the spring 16 acts in conjunction with the notches 15 in the periphery of thedials, each of the notches being exactly in alinement with the numeral, character, or sign on the dial, and thus serves as a guide or pointer by which the adjustment may be effected with facility and accuracy. The adjustment may, however, be elfected in several other ways, and I do not, therefore, confine myself to any particular device in this respect. For example, the disks 14 may not be fast on the spindle 9, but supported around it, and the spindle may carry an index or radial pointer which can be turned to any of the positions by the thumb-nut 12. Or, again, the dial may be fast on the spindle, but entirely inclosed or covered up with the exception of one little window in a cover-plate, through which one of the numerals, characters, or words may be exposed at a time.

The contact-linger which works in conjunction with the contact-plates 4, 5, 6, 7, and 8 is of course electrically insulated from them and is carried by a movable earth-connected ITO block 17. This block is mounted upon a supportin such a manner as to be capable of moving transversely over or past all the contacts on the contact-plates should all these contacts be exposed in its path, its contact-finger 30 brushing across the contacts as it travels. As a means of support for the block in question I prefer to mount, it upon a screw-spindle 18, having, preferably,a helical thread, the block having a correspondingly-screwthreaded hole through it. The block is threaded on the spindle and the latter supported in end bearings, so as to be free to turn. This spindle 18, then, is supported at each end in bearings in sucha manner as to be capable of being freely rotated about its axis,

i but incapable of any longitudinal movement.

This spindle is rotated in one direction by hand by means of the toothed sector-lever 25, (best seen in Fig. 2,) which is pivoted to the frame at O and engages with apinion 19, fast on a toothed wheel 20, which engages with teeth 18t on the spindle 18, the movement being preferably regulated'by means of a fan 28, through the intervention of a train of wheels consisting of the pinion 29, fast on the fan-spindle, the toothed wheel 20, in engagement with a pinion 21, fast on a toothed wheel 22, which engages with a pinion 23, fast on a toothed wheel 24, which is in engagement with the pinion 29 on the fan.

The armature 26 of the magnet 3 is pivoted at 27, and the extremity remote from the magnet is provided with a pin 27', which normally-that is, when the magnet is denergized,and therefore not holding its armatureis in engagement with or resting against a notch or stop-tooth formed in or upon the periphery of a plain wheel or disk 90, mounted fast on one of the spindles of the winding-up train of wheels, preferably the one bearing the toothed wheel 20. The coperation of this pin and tooth or notch serves to hold the train of wheels when wound up to prevent it running down until purposely released by a current from the exchange, as is. fully explained in turn hereinafter.

R C is a revolution-counting device, which may b e combined with the latent switch when calls are paid for by meter. It may be of any well-known construction as far as the actual counting mechanism is concerned, but in order to adapt it to the switch I provide it with an external-toothed wheel 76 and the block- 17 with a crank-pin 77, so that should a call be eective the said pin, just when the said block reaches the end of its stroke, will strike in the teeth of the wheel 76, and thus revolve the set of numbered disks ot the counter, and so register the number of calls made and act as a meter, which will always be in sight, so that the calls may be checked as made. ,v

Instead of the contact-'plates being movable to expose the nu mber of contacts desired these plates may be xed and a movable insulator adapted to move over them, so as to cover up a greater or less number of the contacts employed, and thus leave exposed only as many as may be required for the call.

The main or winding-up-lever serves to rotate the spindle 18 in one direction, which winds up the block 17 or causes it to ascend or move in one direction, carrying with it the contact 30, which brushes across all the contacts on the contact-plates which lie in its path at the moment.

The indicator-switch may be used in any position. When used vertically,thenutblock 17 on the helical spindle 18, bearing the flexible contact spring or strip 30, will be raised by the hand-lever sector-rack 25 engaging in the pinion 19, fast on the toothed wheel 20, which rotates the helical spindle and so raises the said nut, while in its downward motion it will fall by gravity. Should, however, it be desirable to use the instrument in any other position-say horizontal-the movements of this nut-block in the unwindingdirection, it is obvious, might be effected by means of a spring or other source of power, which is either wound up orextended when the nut is moved in the other direction by the windingup lever 25, and consequently the potential energy thereby stored in it will constitute the latent force necessary to automatically return the block to its initial position when released.

31 is a spring-catch made to engage in a hole 32 in the back of the dial 1/l,bearing the numerals or characters corresponding to the various exchanges, dac., whenever the said hole in this dial is presented to the tooth on the end of the saidspring-catch 31. The object of this is fully described under the heading Calling and operating.

The electromagnet 3 is normally deenergized-in fact, cut out ot' circuit altogetherby the make-and-break contacts 32 33 and 34 35.

33 represents guide-arms on the blocks 17, which arms, cooperating with the guide-bar 34, along which they travel when the said block is in motion, serve to keep the block free from any lateral play.

The block 17 is preferably connected to earth, this connection being indicated in the drawings by the earth-plate E. The contactplates 4, 5, 6, 7, and 8 are connected with the line-wire L and the contacts l2, 52, 62, 72, and 82 with the line-wire L2.

In Fig. 9 the connection of this switch with the printing apparatus, jack-switch, and special indicator at the exchange is shown.

Exchange printen- The exchange printer-that is, the printing apparatus which prints the name or its equivalent of the exchange or other special office desired in a call and operated electrically by means of the latent switch just above described-is shown in detail in Figs. 5and 8; also, its connections with the special jack-switch J S and the special indicator S I, Figs. 6 and 7. This printer is a modification of an ordinary printing or recording telegraph. It consists of an electromagnet C M, hereinafter referred to as YOO IIO

the contact-magnet, electrically connected with the line-wire L and earthed at E2 through a battery P B, a type-wheel 35, bearing in type letters, figures, words, or other characters or signs representing the various exchanges and other offices, if desirable, the types being arranged around the periphery of the wheel and the number of them corresponding with the number of contacts 4' on the exchange contact-plate 4 of the latent switch. This typewheel is operated automatically by the coperatiou of the magnet 3, traveling contact 30, and the contacts 4 of the latent switch,in conjunction with electric currents emanating, preferably, from the battery P B, but not necessarily from the exchange, the working being effected through the medium of the armature 36, pivoted at C', of the magnet C M, the ratchet escape-wheel 37, the pawl or detent 38, and the double tripping-lever 43, the detailed actions of which will be described later on under Calling and operating. Another electromagnet P M, hereinafter referred to as the printing-magnet, is electrically connected with the line-wire L2 and governs an armature 40, pivoted at'O2, the tripping-lever 39, above mentioned, type-hammer 41, a pair of feed-rollers 42, and a detent 43, which latter, in conjunction with the ratchet 45 on one of these rollers, turns the roller and advances the tape for spacing purposes by friction with its surface. A lever 46, pivoted at O3 and bearing a tooth 47, adapted to be brought into and out of engagement with the teeth of the escape-ratchet 37,will be described,as regards its functions, later on. The supply of paper tape maybe carried, as usual, in the form of a roll upon a skeleton bobbin 48, mounted in a bracket, so as to be free torevolve. I R are the inking-rollers. This printingr apparatus maybe at will electrically connected with the line-wires, as above stated, through the mediuln of the special switch next described.

Oscillatory jack-switch.-This switch is a modication of the well-known jack-and-plug type. The line-wi res L and L2 terminate in a plug J P, the wire L in the metallic sleeve of the plug, andthe wire L2 in the metallic tip of the plug,the tip and sleeve being of course electrically insulated one from the other. This plug J P shown is a modification of the ordinary one, having its lines leading in through a stem orarm 58, which projects out from about the center of the underneath side of the plug,

and at right angles thereto, the object being to prevent the wires getting broken by frequent bending, as they do when they are led in at the rear end of the plug, because in the latter case the pushing into and pulling the plug out of the jack or socket bends the wires in reverse directions, and this frequently repeated, as it necessarily is in busy exchanges, necessitates frequent renewal. It will be noticed that with the design of plug shown in Fig. 6 the wires are always quite clear of the rear end of the plug, so that this can be thrust in thejack, as usual, without fear of crushing the cord containing the wires between the hand and the rear end of the plug. Moreover, the rigid stem provides a firm grip with which to pull the plug out of the socket with greater facility. The jack consists of the casing 59; but instead of the bush 60, of insulating material, at the entrance of the jack for the reception of the plug being stationary, as usual, it is piVoted at O4, so as to permit the plug when inserted to be tilted, so that its tip points downward, as shown in dotted lines. Normally the plug J P rests in the jack in an oblique position, with its tip pointing downward. A spring 6l, engaging in notches 62 in the oscillatory bush, is provided to hold the block in the position in which it is put. The free end of said spring rests normallyin one or other of said notches and rides out of theml when the block is moved with slight force, but not by the mere weight of the plug. A set of spring-contacts 52 53 54 55 56 57 are fixed in an insulating-block 63, secured in the rear end of the casing 59. The springs 52 and 53 are shown electrically connected through the plug J P with the line Wires L and L2, respectively, and through connection wires with the exchange printer, and When the plug 49 is inserted in the jack horizontally, as shown in Fig. 6, these two springs make contact one with the tip and the other with the sleeve of the plug, so that the said printer at the exchange is thereby thrown into circuit with the subscribers latent switch when desired. The springs 54 and 56 are connected through a generatoror battery E B to earth, (indicated by the plate E4.) These lare for the purpose of giving the engaged or busy signal to the calling -snbscriber when the called-subscrihers line is already engaged,the indicator in question consisting of eithera special magnetic bell or an electric bell 76 and electromagnetic device 77, such as shown in combination at E S, Fig. 9, and which is further described u nder Calling and operating. Normally the plug J P being in the inclined position makes contact by its tip with the spring-contact 55 and by the sleeve with the contact 57, slightly depressing these two contact-springs, so that they break contact with the two springs 54 and 56. Consequently when the said plug is either drawn out or lowered into the horizontal position, the two springs 55 and 57 being thereby released spring up and make contact with the two springs 54 and 56, as shown in Fig. 6, and th us automatically actu ate the indicator when the line is engaged, as desired. The cont-actsprings 55 and 57 are in electrical connection with the special indicator S I at the originating board and jack S B at the switching-board, these connections being obvious from a glance at Figs. 6 and 7 or Fig. 9.

In Fig. 9 the two contact- springs 55 and 57 are shown in contact with two stud-contacts, these latter being merely substitutes for the contact-springs 54 and 56 in Fig. 6.

Any one or more of the contactsprings IOO IIO

shown in the jack .l S, Fig. 6, 'may be replaced by contact-studs or other suitable forni of contact.

electrotnagnets 64 and 65, the one coil, 64,'

having one of its terminals normally in electrical connection with the line-wire L' and the one, 65,*one'of its terminals in connec-l tion with the line-wire TP through the medium of the springs 55 and'57 of thejackswitch J S, the plug 49 of which normally rests in the said jack in an oblique position, so that the tip 50 of the said plug is in contact with the spring 55 and sleeve 51 in contact with the spring 57, as shown'iu dotted lines. The other two terininals'of the coils in question are connected through a battery to earth, (indicated by the plate E5.) The poles of this electromagnetic device have their inner sides, which face each other, preferably finished obliquely, as shown at 66, and be-v tween these poles is hung or pivoted the armature 67 in such manner that it can oscillate from the one side to the other. At the opposite end of this armature is a rigid cross-v bar, on each extremity` of which is fixed, at an angle thereto, a disk or plate 68 69, which disks advantageously diierin color or are otherwise rendered visibly distinguishable: In front of the armature and supported centrally between the two magnets is a window 70, the whole being so arranged, as will be seen, that attraction of the armature to one pole or the other brings [one of the disks or plates 66 or 69 on the ends ot' its cross-bar to appear at the window 70. This indicator and its functions are further dealt with underv the heading Calling and operating, but it may be here briefly mentioned that it serves to indicate at aglance'to an operator at the eX- change whether a call is for a subscriber on that exchange or some other or distant one, and this is understood according to which disk 68 or 69 -is presented at the window 70 or other predetermined arrangement, as the case may be. Fig. 7 shows the armature of this indicator in one of the positions it assumes the instant a call is made by means of the latent switch first-above described.

The numerical printer and its circuits.- 'lhe instrument or apparatus called the numerical printer and shown at N P, Fig. 12, is the device for automatically printing the subscribers numbers. It consists, accordingly, of a type-wheel 91, bearing, preferably arranged in a circle around its periphery, the numbers 1 to 9, a 0, and a dot or dash or other sign representing zero. .There are thus eleven signs in all, corresponding with the eleven contact-ridges 5', 6', 7, and S on each of the plates 5, 6, 7, and 8 of the latent switch shown in Fig. 1. This type-wheel is connected with a ratchet-and-pawl mechanism substantially similar to that described abovev in connection with the exchange printer. VIt is also similarly connect-ed with electromagnetic devices and provided with paper-tape roll and inking and spacingdevices and may he also fitted with-means for.l bringingy the wheel back to zero-each time 4after itV has printed a ligure, this latte'nhcontrivancev being to save the type-wheel having tomake a complete revolution after printing each figure of the called-su bscribers number. kvV' S V S are two visual or lightsignals'operated by current-s sent through relays C R C R. R3 and Rfare resistances bridged across the line-Wires preferably at the points and in the manner shown in the iigure and 4serve to prevent the electrical balance of the line being upset by the'earth connected at E7. Thesesignals V S light up at each operating-board simultaneously on the operators plug being inserted in the jack L S B, and they remain alight until cutout of circuit when cutting in the numerical printer. They are also subsequently lighted by earthing the current ou the lines automaticallybythe weight of the receiver when placed on the switch-hooks at vthe end of a conversation, and thus also serve as clearing signals to the operators.

The functioning of the above signals is also further described under. Calling and operating'farther on. Y

Calling and operatingl will now procee-dl to describe in detail a call and the operating thereof, For the purposes of this descriptionit will be assumed that a subscriber,.whotn for convenience I will call A, wishes to speak with a subscriber B, vBs number being, say, 4105 on the local eX- change and this exchange indicated by the numeral 2 on the exchange-dial 4. A is therefore the calling-subscriber and B the called subscriber, and the call and operating thereof will be effected by the combination of apparatus hereinbefore described, the subscribers latent switch employed being of the gravity type, as in Fig. 11. To start the call, A first sets the dials of thel latent switch to the exchange and number on that exchange assigned to B. This is done by merelyturning the knobs 12 in the outward direction, these actions advancing the respective contact-plates till they expose just the right numberVofcont-acts corresponding to the eX- change and number desired,and asthe exchange assumed in the present call is the lo'- cal one and the numeral on the corresponding dial 14 denotes this exchange A simply turns the said dial until the springpointer 16 drops into the notch of the said dial immediately over the figure 2 on the face of the dial, thus advancing, as desired, the plate 4 through the medium of the rackand-pinion device at the back and exposing two of its contacts 4 in the path of the contact-brush 30 on the traveling block 17. A

next in like manner sets the numeral-dials 5, 6, 7, and 8, respectively, to 4, 1, 0, and 5, thus setting Bs number and TOO exposing in the path of the contact-brush 30 corresponding numbers of contacts. Having done this, A next winds up this switch by simply bringing around the hand-lever 25 by means of its handle as far as it will go toward the opposite side, this action, through themediutn of the toothed sector on the said lever, the wheel 20, pinion 19, and teeth 18t'o11 the spindle 18, rotating the latter, which thereupon carries up the nut-block 17, bearing the contact-brush 30.l The height to which this block will be thereby raised depends always upon whether the call is for a subscriber on the local exchange or some other exchange. For calls on the local exchange itis arranged so that they block will be arrested when it has arrived about half-Way up in ordet that the contact 30 shall not actuate the exchange printer at the exchange, because that is of course unnecessary for a call 0n the local exchange, as the special indicator (see that heading) has in the meantime indicated it. It is only required when Bs number is on some other exchange to inform the operator at the local exchange what other exchange is required. This arresting of the contact-block 17 is automatically brought about by the tooth on the upper end of the spring-catch 31 springing into the hole 32 in the exchange-dial as soon as the said hole is presented to it, which, as before explained, is arranged to ltake place whenever the dial is set for local exchange. On the lower-or tail end of this spring-catch 31 is a projection 73, which is brought into the path of the traveling block 17, or rather into the path of an insulated stud 74 on the said block, when the upper end of the springcatch 3l is in engagement with the hole 32 in the exchange-dial'by reason of the said spring turning on its pivot 75, thereby tilting its tail end backward. Just as the block arrives at the point at which it is arrested, as above explained, it drops slightly and presses the contact 35 against the contact-stud 34, which is in electrical connection with the line-wire L, which in turn is in connect-ion with the special indicator S I (see Fig. 7) at the exchange through the plug J P and springs 55 and 57 in the special jack-switch J S. The current waiting on the line is thereby earthed; but the current is only a feeble one from the battery I B and not sufficient to energize the electromagnet 3, (see Fig. 1,) although this current will traverse this coil to earth; but the said current is sufficient for actuating the special indicator S I at. the exchange, which itdoes immediately the traveling block makes the said contact. The normal position of the armature of the indicator S I is central, as shown in Fig. 9. The two line-wires L and L2 terminate in the jack-plug J P, the one L" in the sleeve 51 of the plug and the one L2 in the tip 50. This plug, as already explained, normally rests in the jack-switch J S in the inclined position, as indicated in dotted lines in Fig. 6, consequently making contact with the springs 55 and 57, which close the circuit in which the indicator, Fig. 7, is included. rThis indicator S I having been actuated, one of its disks (the one indicating local exchange) is thereby presented at the little window 70, as in Fig. 7, thus indicating to the operator who iirst receives the call, and hereinafter referred to as the originatingr operator, that the call is fora number on that exchange. The call 'having been thus announced, the operating is commenced by the originating operatoratthecalling-board pulling the plug J P out of tht-jack J S, thereby locking the subscribers switch by cutting ont all connection with the indicator S I. The contact- springs 55 and 57 thereupon spring up and tnake contact with the two contactsprings 54 and 56, respectively, which are connected through the batteryEB to earth, (indicated by the eatt h-plate E4.) This is for the purpose of giving the engaged or busy signal to any other calling subscriber, automalical ly indicating to hitn that the line is engaged. This busy or engaged indicator preferably takes the form of a bell-indicator, such as shown at E S, Fig. 9, "wherein itconsists of an ordinary electric single-stroke bell 76 andan electromagnetic device 77, the armature 82 of the latter being pivoted at 78 and bears at one end a plate 79 bearing the wordEn gaged or similar information, this plate heing exposed at an aperture 80 in a board 81 in front whenever the armature is attracted by the magnet. The bell 76 in it-s entirety might obviously be dispensed with and in lieu thereof a simple gong might be mounted within reach of tite armature S2 to strike. The plug is then inserted in a jack of a local junction connection leading from the callingboard to the switching-board, this action putting the visual signals V S in circuit, and consequently lighting them. The operator there then plugs the jack leading to the numerical printer to ascertain the num ber wanted. The numerical printer being now in circuit, the current on the lineL,emanating from the battery P B, is strong enough to energize the coil3, Figs. l, 9, and 13, attracting its armature, and thus releasing the catch 27 at the end of the lever out of the notch in the wheel 20, and thus releasing the Winding-up mechanism. The block 17, carrying the contact 30, then commences its descent, breaking the contact at 34 35, and consequently taking the earth Eoff the line, said contact brushing in succession those contact-ridges ot' the plates 5, 6, 7, and Swhich lie in its path, and thereby giving a corresponding number of pulsationsto the armature 36 of what [will call the contact-magnetC M of the printerin question, thus rotating the type-wheel to the figure to be printed, and on the contact 30 arriving in its descent at the contact- studs 52, 62, 72, and 82 it earths at E', the current now coming fromv the battery N P B, which causes a pulsation of the armature 10 of what I willcall the printing-magnet PM', thereby pressing the printing-hammer and paper TIO against the type, and thus producing theimprint. This action in detail is as follows: To the armature 36 is pivoted at 83 (see Fig. 5 for the details) a bent lever 39 and at 84 a pawl 38, so that the said armature carries with it when attracted this bent lever, the tip of which on coming in contact with the lfixed stop 85 becomes depressed, thereby throwingr out its other leg, on which there is a pin 86, which latter pushes back the detent 43 oft the tips of the pawl 38, and a lever 46, having a tooth 47, thereby releasing the said paw] and lever 46, both of-which being springpressed immediately engage in the teeth of the `ratchet escape-wheel 37. Each time the armature drops it causes, by means of the pawl 38, av tooth -by-tooth rotation of the ratchet, which in turn rotates vthe respective type-wheel 35, thesepulsations occurring for every contact on the plates 5, 6, 7, and 8 brushed by the contact-spring 30, thus causing the proper type to be presented to the typehammer, and on the said contact-spring arriving at each of the contact-studs 52 62 72 82 a pulsation is given lo the armature 41 of the printing-magnet PM'. On this armaturebeing attracted by its magnet the printing-hammer 41 strikes the paper against the type-wheel, thereby printing on the paper the number, character, or sign which is presented at that kpoint of the type-wheel immediately above the paper at the moment. Simultaneously the detent 43 is raised, and during the descent of the armature the detent 43 again catches on the ends of the pawl 38 and toothed lever 46, bringing the former out of the teeth of the ratchet-escape 37 and the tooth on the lever 46 also out of engagement with the said escape-wheel, thus leaving the latter free to be turned back to its zero or initial position under the influence of a coiled spring 105 within the barrel of the said wheel, which spring has ofcourse been wound up by the pawl 38 during the pulsations of the armature 36. When the armature drops, it also brings down with it the detent 43/, which,catching'in its descent in one ot' the teeth of the ratchet 45, fast on the friction-roller 42, rotates this roller, thus by friction rotating the other roller 42 and advan cing the paper tape between them for spacing purposes after each imprint. The nurnber being thus ascertained and printed for future reference, the call is completed by connecting this number by taking the plug out ot' the jack 49 and putting it into the called-subscribers` jack S B'. The operator then depressesa key K, connected in thelines, which action causes a signal (bell'C B to ring to be given to both subscribers, indicating that the connection required is Icompleted.

The above is a description of the series of events or operations which take place to put one subscriber in connection with another on the local exchange. I will now proceed to describe what would take place had Bs number been on some other or distant exchange.

A would set his dials as before, except that the exchange-dial would of cou rse beset to an i block 17 and obstruct its upward passage, asV

before, so that when the switch is wound up by the toothed sector-lever 25 the block 17 will be thereby carried right to the top and press the spring 32 against the contact-stud 38, thereby earthing the latent current onto the line L', the said current originating at the battery I B, thus actuating the special indicator, Fig. 7, at the exchange, as before. The operator at the calling-board new knowing .that the call is for some distant exchange must ascertain which one, so instead of pulling the subscribers plug J P out of the jack .I S simply brings it down into the horizontal position (shown in full linesin Fig. 6,) thus cutting out of circuit the indicator S I and cutting in circuit the exchange-printer E P, Figs. 5 and 8, which thereupon prints the name of the exchange wanted. The contactsprings 55 and 57 being released ily up and make contact with two other springs 54 and `56, which are connected through a generator or battery to earth, (indicated by the earth-VA plate E4.). This is for the purpose of. giving the engaged or busy signal, as previously explained. The mechanism and operation of the exchange-printer are almost identical with those oi" the numerical printer and so needy not be here repeated, the difference consisting in the type-wheel containing on its periphery words, numerals, characters, or other signs denoting exchanges, 85e., instead of the numerals for the numbers, as in the other printer. Either or both of these printers may be made simpler, it' desired, by eliminating the mechanism for returning the type-wheel back to zero aft-er each print. The name of the distant exchange being thus ascertained, the originating operator plugs As line direct into a jack corresponding to L S B, leading to the switching-board of that exchange instead of, as in the former case, to the switching-board at the same exchange, and the call is then completed b v the operator at this switching-board, as in the former case. Thus without any intercourse with the operators at the exchange the most coinplex telephonie service can be supplied by means ofthe combination of apparatus above described.

Most of the apparat-us is of novel construction and specially adapted one instrument to the other as well as to the whole system, to carry out the invention in the best way, although in a fundamental form some of the instruments, I ain aware, are not novel for other' uses than telephony.

The apparatus and system described in this specification have been devised with the London system in view, so that certain modiications, which, however, are obvious, must IIO be made in some of the apparatus and also in the way they are grouped to adapt them to the service to be supplied. For instance, the exchange-printer herein described is constructed to print the names or equivalents therefor of exchanges and other offices numbering fifty in all; but it is obvious that this number is entirely dependent upon the number of exchanges, &c., and where there are no junction exchanges the exchange-dial and contact-plates can be dispensed with entirely. As regards grouping, the combinations may be also altered to suit the requirements and some of the instruments may be omitted entirely. For instance, the compound indicator might be dispensed with where there is only one exchange-that is, where there are no junction or distant exchanges as Well as the local one-and, again, other equivalent instruments maybe substituted for those eliminated. For example, instead of the subscriber-s latent switch being made to operate a printing device the latter may be eliminated and a revolution-counter or a counter-indicator substituted therefor, the said counterindicator being operated by impulses imparted to a lever-armature in exactly the same way as the printer is worked.

The end of a conversation is made known to the operators in the exchange by the following means: 92 (see Fig. l) is an electromagnet normally denergized, but supplied by a current when required from the exchange, so that the clearing-signal can be received there, said current being derived from the batteries R O, indicating ring off.7 (Shown in Figs. 12 and 17.) The armature 93 of this magnet is held normally out of or beyond the magnetic field by means of the spring 94, but is automatically brought into the ield when the hand telephone set 95 is placed on the switch-hook arm by reason ofthe weight bearing down the said hook, which by its central stem 96 depresses the pivoted link f 97, causing the detent 98 on the latter to catch on the tip of the armature 93 and pull it down. Immediately the armature is in the iield the spring 94 makes contact with contact 100, which is earth-connected at E6, thereby earthing the current on the lines, which energizes the coil 92, and the armature 93 is drawn on to the magnet, in which position it makes contact with the two contact-springs 99 and 100, thereby closing the circuit, putting an earth on the line by reason of the spring 101 and 102 being always in contact with the link 97, so that the clearing-signal can be received in the exchange, the spring 101 being in connection with the line-Wire L' and the spring 102 in connection with the linewire L2. This earthing of the current on the line causes the lamps V S in the exchange to light up, which serves as the clearing-ont signal to the operators, and these lamps remain alight until the clearing is done.

Thus this invention consists of a group of apparatus for automatically electrically signaling connections required from subscribers to the telephone-exchange operators and from one exchange to another without either subscriber or operator speaking, thus securing secrecy of messages, as telephone instru ments form no part, necessarily, of the operators apparatus, and they are therefore unable to tap or tamper with the wires. The circuits are very materially simplified, and Amultiple switchboards even for the largest exchanges are dispensed with, thereby saving enormous expense in construction and maintenance and doing away withnumberless sources of faults and wrong connections. With this system it would be possible to carry on the operating with from twenty to fifty per cent. of the stai required by the systems now in use. It is considered to be an improvement on the purely automatic systems, it is available for the largest as well as the smallest exchanges or groups, whereas the automatic systems will only work satisfactorilyup to a limited number, and the mechanism is necessarily too elaborate and costly. In the case of multiple switchboards the cost per subscribers line increases as an exchange grows; but with this system the cost per line would always remain the same and the prime cost per line would be very much less.

The novelty of the invention consists in part of the general arrangement or combination of the parts which in diierent forms have been used for other purposes, but not for telephony, and also some of the parts are novel-such, for instance, as the apparatus or latent switch at the .subscribers endwhereby he can set his dials to the number required, and the switch is worked preferably by currents from the exchange when the operator is ready to operate the call.

What I claim, and desire to secure by Letters Patent, is y l. Asemi-automaticlatentsignaling-switch for actuating and controlling a distant indicator or signal, consisting of a frame in electrical connection with one terminal of the circuit, lnovable contact-plates, a contact-piece on the, frame, an externally-screw-threaded spindle rotatably mounted in, but insulated from, the frame, means for rotating the spindle in one direction, a traveling nut-block mounted on said spindle, and a contact carried by the nut-block in electrical connection with the other terminal of the circuit, and adapted to brush the contacts on the plates and frame, substantially as described and shown.

2. The combination with an electric circuit and a distant indicator or signal included in the circuit, of the semi-automatic latent signaling-switch for actuating and controlling the said indicator or signal, consisting of a frame in electrical connection with one terminal of the circuit, movable contact-plates, a contact-piece on the frame, an externallyscrew-threaded spindle rotatably mounted in, but insulated from said frame, means for ro- IOO IIO

tating the spindle in one direction, a traveling nut-block mounted on the spindle, and a contact carried by the nut-block in electrical connection with the other terminal of the circuit, and adapted to brush the contacts on the plates and frame, substantially as described and shown.

3. The combination with an electric circuit and a distant indicator or signal included in the circuit, and the semi-automatic latent signaling-switch for actuating and controlling the said indicator or signal, consisting of a frame in electrical connection with one terminal of circuit, movable contactplates, contacton frame, screw-spindle rotatably mounted in the frame, traveling contact-block on said spindle in electrical connection with other terminal of saidI circuit, of a revolutioncounter actuated by a projection on the said traveling contact-block engaging on its downward travel in the driving-wheel of the counter substantially as described and shown.

4. The combination with an electric circuit a distant indicator or'signal included in the circuit, and the semiautomatic latent signaling-switch consisting of a frame in electrical connection with one terminal of the circuit,

' contact on the frame, screw-threaded spindle rotatably mounted in, but insulated from the frame, means for rotating the spindle, traveling nut-block, contact on said block in electrical connection with other terminal of the circuit and adapted to brush the contact on the frame, of an electromagnetic printing device, a simple switch for cutting said printer in circuit and means for actuating said printer from the semi-automatic latent switch, consisting of the adjustable contact-plate, an electromagnet, the armature of which is adapted to release the traveling contact which then falls by gravity lits contact brushing the contacts on the adjustable plate thereby causing the pulsations of the printer, substantially as described and shown.

5. ln apparatus for use in connection with telephonic intercomin unication, the combination with an electric circuit, of the latent switch, the special compound indicator, the special jack-switch, the line-wires, the eX- change-printer having mechanism arranged and adapted to return the type-wheel to zero or initial position after each print, and means for actuating, locking, and releasing the latent switch, substantially as described and set forth.

6. In apparatus for use in connection with telephonic intercommunication,the combination with an electric circuit, of the latent switch, the special compound indicator, the special jack-switch, the line-wires, the eX- change -printer, and means for actuating, locking and releasing the latent switch,- substantially as described and set forth.

7. In apparatus for use in connection with telephonic intercommunication the combination with an electric circuit of the latent switch, the compound indicator, the jackswitcli, the line-wires, the exchange-printer, having mechanism adapted to return the type-wheel to initial position after each print, and means for actuating, locking and releasing the latent switch, of the numerical printer, an oscillatory jack-switch adapted to cnt said printer in and out of circuit with the compound indicator and visual signals, all constructed, combined and operating, substant-iallyas described and set forth.

The combination of apparatus constituting a complete semi-automatic system of telephonic intel-communication, comprising in combination with electric circuits, telephone transmitter and receiver, indicator-bell engaged or busy device,the means for bringing the armature of the clearing-electromagnet into the magnetic field automatically by the weight of the transmitter and receiver when on the switch-hook, the latent switch, the automatic revolution-counter, the linewires,the oscillatory jack-switch and plug, the compoundindicator,the eXchange-printer,the visual signal devices, the exchange-printer, the numerical printer and intermediate jackswitch for connecting either with the line, all; constrncted,combined and operating substantially as described and set forth.

9. In a latent switch for use in connection with signaling telephonic connections desired, the combination with the exchange-dial and traveling contac'tblock, of a hole and spring-pressed catch adapted to engage in said hole when same is presented to it, a projection on the tail end of said catch adapted to project in the path of the traveling contactblock automatically on the dial being set to a predetermined point, substantially as described.

10. The apparatus whereby a signal is transmitted to a distance by the weight of the telephone hand set when placed on the switchhoolgconsisting of the combination with the stem of the switch-hook, of electromagnet the armature of same pivoted normally out of the magnetic field, a pivoted lever carrying a detent adapted to engage when lowered on the tip of the free end of the said armature and bring it into the magnetic field, two contacts constituting terminals of the electric j circuit in which is included an electrical signaling device, substantially as described and set forth.

11. An electric or magnetic printing apparatus the combination of the typewhee1,. means for rotating same step by step, means for inking the type, the magnetic or electromagnetic device,the armature,the ratchet and pawl for rotating the type-wheel the magnetic or electromagnetic device and the printinghammer, the combination therewith of the spring located in the type-Wheel and tending always to hold the wheel at normal position,

IOO

IIO

TLO

the bent lever pivoted on the rotation-arm, the double detent pivoted on the printing-zu'- mature adapted to en gage with the actuating- Iu testimony that I claim the foregoing as myiuvention I have signed my name in pres- I ence of two subscribing Witnesses.

ARTHUR THOMAS MILNOR THOMSON. Witnesses:

ROBT. A. BLAKE, FRED C. HARRIS.

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