US355929A - Telephone switch system - Google Patents

Description

(No Model.) 3 Sheets-Sheet 1.

G. G. GOULD & W. SMIT-H. TELEPHONE SWITCH SYSTEM.

No. 355,929. Patented Jan. 11,1887. b @ya ,Q @MISES a sheets-'sheen 2.

(No Model.)

G. C. GfOUL'D4 8v W. SMITH. TELEPHONE SWITCH SYSTENL Eid 3 sheetssheet s.

o. o. GOULD an' W. SMITH. TELEPHONE SWITCH SYSTEM.

No. 355,929. y1/Patented Jan. 11, 1887.

(No Model.)

N PETERS. Phufu-uahngmpner. wnningmn, nc,

UNrre Srarss i ArtNr. trice..

CLAUDE C. GOULD'AND NVALTON SMVITH, OF BATAVIA, ASSIGNORS OF ONE- i FOURTH TO PHlLlP XV. SORIBNER, OF TONAVVANDA, NEV YORK.

TELEPHONE SWITCH SYSTEM;-

SPECIFICATION forming part of Letters Patent No. 355,929, dated January 11, 1887.

Application filed September 2, 1886. Serial No. 212,450. No mudcl.)

To all whom z' may concern..-

Beit known that we, CLAUDE G. GoULD and WALTON SMITH, of Batavia, in the county of Genesee and Sl ate of New York, have invented new and useful Improvements in Telephone Switch Systems, of which the following is a specification.

This invention relates to a switch-board system in whicheach main or subscribers line IO is provided in the central office with a movable terminal, which is automatically moved out of its normal position so as to break the connection with the ground upon sending a current through the line. A switch-board system of this kind is described and claimed in another application for patent inthe United States iiled by us February 23, 1886, Serial No. 192,755. In our former application for patent the automatically-inovable terminal is applied to a system of ground-circuits.

The principal object of our present invention is to render the automatically-movable terminal applicable to a system containing l metallic circuits.

Ourinvention consists oftheimprovements,

which will be hereinafter fully set forth, and pointed out in the claims.

In the accompanying drawings, consisting of three sheets, Figure l is a diagram representing three sectional switch-boards of a central otlice provided with our improved system.

Fig. 2 is a diagram representing the manner of connecting the subscribers on one section each with the other, and also how said subscribers are reached from either of the other sections. Fig. 3 represents a sectional elevation of-one ofthe switch-levers, annunciators, and connecting parts on an enlarged scale. Fig. 4 is a sectional elevation in line .fr w, Fig. 3, 4o looking forward. Fig. 5 is a front elevation of the vibrating lever. Fig. 6 is a side elevation of the front portion of the same on an enlarged scale. Fig. 7 is a horizontal section in line i/ y, Fig. 3. Fig. 8 is a top plan View of one oi' the levers. Fig. 9 is a fragmentary rear elevation of the switch-lever. Fig. l0 is a diagram representing a through connection between a metallic-circuit subscriber and a groundcircuit subscriber. Fig. ll is a dia- 5o gram representing a local connection between nected with the ground by a wire, d6.

a metallic-circuit subscriber and a ground-circuit subscriber.

Like letters of reference refer to like parts in the several figures.

A Al A2 represent three sectional switch- '55 boards, arranged side by side, the upper portions, c, of which are preferably arranged vertically, or at right angles to the lower or table portions, c. Each table portion a of the sections A A A2 is provided with a number of 6o disks or rings, D. These disks are preferably constructed of gutta percha, wood, or other suitable non conductive material, and are iirrnly secured in openings formed in thetable portions a' in any'suitable manner. Each disk 65 is composed of two parallel parts, d d, ar-V ranged one above the other, and are connected by a central hub, di, as clearly shown in Fig. 3. The Iupper part, d, of each disk is provided with a contact-point, d", and the lower part, 7o d, with a contact-point, d, arranged below the point di. The Apoints d d* are connected by a metallic bowspring, (Z5, which is con- The spring d5 engages with its lower portion, dl, 75 against the under side of a nose, d3, formed in the point dt, and with its upper portion, d, against the lower end of the point d3, wherebyv both points d3 and d* are connected with. the ground when the parts are in the p-osition 8o shown in Fig. 3. The bow d5 practicallyforms a movable connecting terminal between the two contactpoints d3 d4 of the'main circuit. The contact-spring d5 is secured to the front end of the lower forwardly-bent portion of a vertically-movable switch-bar, E, arranged in rear of the vertical portion a of the sections. The bar E is guided in its movement by screws e, passing through slots e', which are secured in brackets e2. The latter are secured to the 9o rear side of the Vertical portion a.

ye3 e4 represent two out or dead contact-points arranged one above the other in the disks d d', respectively. The points e3 e4 are connected by means of cords e5 e6 with metallic contact- 95 surfaces e7 es, formed on the opposite sides of a non-conductive plug, c, which latter is seated in an opening, el, formed in the Vertical portion c of the section.V

F represents the annunciator; F, the base loo thereof, which is secured at its rear end to the above the disk D, and G represents a similar vertical portion a of the section, as clearly finger arranged underneath the disk D. rIhe shown in Fig. 3. Each annunciator is profingers G G bear in their normal position 7o vided with two aprons o r drops, j' f', which with their outer free ends against the ground are pivoted side by side at their lower ends to contact-points d3 (Z4, as shown in Fig. 1. The the front bifurcated portion, f, ofthe base F, inner ends of the iingersG G are respectively and which engage, respectively, with their provided with hubs g g, which are secured to upper recessed portions over hooks or noses a vertical non-conductive tube, G2, seated ccn- 75 f f3 f4, formed on the front end of a vibrating trallyin an opening in thehub d ot' the disk D. 1o armature, f. The armature'f is pivoted in Ga represents a cup secured to the upper the usual manner to a bifurcated standard, f, end of the tube G2 and provided with a screwformed in the base-plate F, and is arranged cap, G1. above two coils, Fz F. The lower portion of g2 represents an arm formed on one side of 8O the apron j' is provided with a downwardly- -the cup G3, and provided with a handle, g,

i5 projecting lip, 7'7, which engages, when released, w-hereby the tube G2 and fingers G G may be against the front vertical portion, f8, of a. horimoved. The tube G2 is held against vertical zontal sliding bolt, f, arranged underneath movement by the fingers G G.

' the base F of the annunciator F. rIhe bolt H represents a step-shaped disk of non-con- 85 f9 is suspended on hangers f1 by screws f, ductive material secured to the lower end of 2o passing through slots fm. the tube G2, so as to turn therewith, and pro- F1 represents a hook formed on one side of vided with a series of annular metal plates or the bolt f, at the rear end thereof, and engagrings, It It h2 h h h5 h6, secured to the lower i ing in a notch or recess, F5, formed in the rear sides of the steps in any suitable manner. 90

side of the movable switch-bar E, near its upi t" t t i* t5 't6 represent stationary metal per end, to retain the bar in an elevated posisprings or contact-points secured to a steption. The bolt ff is held in engagement with shaped cross-piece, il, underneath the table a', the bar E by a spring, f1, and bearing with their free ends against the Upon vibrating or slightly tipping the arunder sides ot' the rings h ZL 7a2 h3 It h5 h6, re- 95 mature f5 by alight current-such as abatspectively. By this construction a unilorm 3o tery-current-the small apron f alone is alcontact is maintained. between the parts when lowed to fall by being released from the hook the fingers G G are moved on the disk. f4, thus notifying the operator upon whose I represents a push-button arranged above table the apron j" has fallen that an operator the cap G, and provided with a downwardlyroc. on some other section or tableis about to conprojecting metallic stem, j, moving in an opennect with said subscriber. Then this occurs, ing in the cap Gi The button I is provided the operator on whosetablethe apron has fallen near its lower end with two metallic contactdoes not loop'inhis telephone, and thus interpoints, j jg, which are separated by a noni fere with making a connection with the subconductor, j. 'Ihelower contact-poindji, pro- 105 scribers desired to be reached. By giving jects outwardly, and is secured to the inner 4o the armature f5 a greater vibration, as by a side of the cup G3, and forms a spring to retain generator, the apronfis disengaged from the theipush-button I in an elevatedposition, as hook fis and .is permitted to fall. The lip fT shown in Fig. 3. The free end'ot' the spring ofthe apron fstrikes the front portion of the or contact-pointj2 bears against the under side tro sliding boltfu and nlovesthelatter backwardly of a projecting nose, ji, formed on the upper and out of engagement with the switch-bar E, end of a metallic stem, j, which latter' is sewhereby the latter is released and enabled to cured in an opening in the tube G'l by a screw, be moved downwardly by its spring F. This js. The latter also serves to form a communidownward movement ot' the bar E breaks the cation between the finger G and stern The 115 connection between the contact-points rZ3 d point j ofthe button I is connected with the 5o Thus, if a subscriber rings, causing the armaline K of the main circuit by means of a wire,

ture f5 to vibrate sufficiently to release the jl, ring h", and contact-spring t". -f apron'f to produce the above-described down- Krepresentsageneratorpush-button, which ward movement of the bar E, the circuit is is provided with a metallic stem, Z, moving in 12o broken between the points eZ;i dt, and he is an opening in the cap G, and provided at its thereby immediately notified that the call has lower end with two metallic contact-points, Z been received at the central otlice from the- Z2, which are separated by a non-conductor, Z3. z fact that he can no longer ring his bell. The The lower contact-point is secured at one end swinging movement of the apron f is limited to the inner side ot' the cup G, to retain the 125 by a nose, f, formed on the upper front end push-button K in an elevated position. The 6o ot' the bolt f". 1 free end of the contact-point Z2 bears against It is obvious that when both aprons are enthe under side of a nose, Z4, formed on the upper gaged with the armature f and the latter is end of a metallic stem, Z5, which' latter is sevibrated by a generator both aprons ff will cured in an opening in the tube G2 by a screw, 13o fall simultaneously. The armature f is held l, whereby a connection is made between the in engagement with the aprons ff by the stem Z5 and the lower finger, G. The lower usual spring, f1, point, Z2, of the button K is connected with G represents a metal Spring-finger arranged the line L of the main circuit by means of a l wire, Il, ring h5, and contact-spring i5. Thus it will be seen that the lines K and L of the main circuit are connected through the fingers G G, contact-points Z3 cZ, and spring (Z5, completing the circuit and enabling the subscriber to call the central oftice.

m represents a stationary metallic contactpoint secured inthe cup G3 underneath the contact-point j! and in line with the same. The contact-poiut mis connected with the operators listening-telephone M by a Wire, on', ring h4, spring 114, and a cord or wire, m2. Thereturn-wire m3 of the listening-telephone is connected with the contact-pointy" of the stem j by means of a wire, m4, ring h3, and spring i3. It willthus be seen that upon depressing the push-button I, so as to form a contact between the pointj and nosej4 and the springpointy'2 and stationary contact-point m, the operators listening-telephone M is looped in on the main circuit.

n represents a metallic contact-point arranged in the cup G3 diainetrically opposite the point m and underneath and in line with the lower contact-spring, Z2, of the push-but ton K. The contact-pointnis connected with the generator N by a wire, n', ring l1?, spring t2, and wire n2. The return-wire n3 of the generator is connected with the contact-point Z of the puslrbutton K by means of a Wire, n, ring h', and spring i. Upon pressing down the button K so as to make a connection between the point Z and nose Z* and the point Z2 and stationary contact n, the generator N is looped in on the main circuit.

-N represents the battery push-button, the metallic stem n of which is provided with a contact-point, n, which is connected with a battery, N2, by means of a wire, nl, ring Zz, spring i, and wire u8. The opposite wire, n, ofthe battery N2 is grounded, as clearly shown in Fig. 3, andestablishes a contact through the ground with the groundwire of the bow (Z5.

`o o represent two-metallic contact-points secured to the rear side of the vertical portion a ot' the section, and arranged one above the other, as clearly shown in Figs. 3 and-9.

o2 represents a bow-spring secured to one side of the upper conductive portion, E', of the switch-bar E, and which is arrangedv between the contact-points o o and bears against the under side of the contact-point o when the parts are in their normal position, as shown in Fig. 3. The upper portion, E', of the bar Eis separated from the lower portion, E2, by a non-conductor, E, which connects the two portions of the bar. Vhen the parts are in their normal position, as shown in Fig. 3, the subscribers line o3 enters the central ofiice from one side of his instrument through the contact-point o, to and through the annunciator F, to the contact-point o', line K, spring t6, metal ring 7L, wirejl, contact-pointy?, metallic stemj-uger G, and coutactpoint d3, and returns through the contact-bow Z5 to the coutact-point d, finger G', metallic stem Z5, to the 'contact-point Z2, wire Z7, ring h5, contact-spring i5, and line L, to the opposite side of the su-bscribers instrument.

p p represent a series of local contact-points secured to the disks dd', the points p p' being arranged in pairs one above the other vin the two parts d d of each disk, so that when the fingers G G are turned to engage with a pair of said points the finger G will engage with the upper point, p, and the finger G with the lower point, p', as shown in Figs. 2 and 3.

Each disk D is provided with as many pairs oflocal contact-pointsp p as there are subscribers on the table, less one, and each of these contact-points of one section is numbered to correspond with the number of the subscribers with which it is connected. Forinstance, the subscriber-s disk D No.1 isprovided with two pairs ot' local co1itact-points,pp, which are numbered 2 and 3. The subscribers disk No. 2 has a similar number of contactpoints.

which are numbered 1 and 3, and the subscribl i ers disk No. Shas its contact-points p 19 numbered 1 and 2. It No. 1 subscriber calls and thereby releases the apronf and switch-bar E, as above described, the operator raises the bar E by a handle, E4, so as to again complete the circuit by connecting the points d3 and d* by the bow-spring The bar E, whenlifted by the operator, does notengage with the hook ofthe sliding boltf", as thelatter is held back out of engagement with the bar by the lip f7 lof the fallen apron f. He then loops in his listening-telephone by pressing on the button I and ascertains that the subscriber Wants, for instance, No. 2. The operator againv allows the bar E t0 descend and break the connection between the fingers G- G'. The operator -now turns the fingers G G on the subseribers disk No. 1 to the contact-pointsp p marked No. 2. Theuppercoutact-point,p, (No. 2,)on disk D No. 1 is connected with the upper IOO contact-point, o, of No. 2 subscribers annunf ciator F by means of a wire,p2, and the lower point, p', (No. 2,) disk No. 1, is connected with the return-wire L of No. 2 subscribers instrument by a leg or wire, p3, as clearly shown in Fig. 3. The operator now presses the generator-button K on No. 1 subscribers disk, which causes the armature f5 of No. 2sub- IIO scribers annunciator to vibrate and release its apronsff and the switch-bar E in the same manner as in the case of No. 1 subscribers first call, thereby automatically breaking the circuit between the points d3 d* and fingers G G on No. 2 subscribers disk D. This movement rings both subscribers bells simultaneously, notifying them that the connection between them is completed. No. 1 is now con nected with No. 2 by wire o3, annunciator F, contactpoint o, line K, to and through finger G, as above described, to contact-point p, disk D,`No. 1, to upper contact-point, o, of No. 2 subscribers annu nciator by wirep, and to No.- 2 instrument by wire o3, returning through instrument No. 2 to wire L, to leg p3, to contact p', No. 2, on No. 1 disk, to and through uger G', as above described, to No. 1 subscribers instrument by line L. The operator now replaces the fallen aprons f j" ot both subscribcertainty than heretofore.

ers7 annunciator F, leaving them ready to be rung off. By thus replacing the apronsf I fall, the operator again replacesthe same, and

lifts the switch-bar E by the handle E of both annunciators until they are again in engagement with the sliding looltj'i. The operator also turns the fingers G G on disk No. 1 back to the points d d4, whereby both subscribers lines are again ready for another call. By connectingv the various subscribers on one section in this manner we dispense entirely with the use of the usual plugs, cords, 85e., for eff'ecting a local connection, whereby the connection is made more rapidly and with greater It will thus be seen that the connection between the two subscribers is entirely metallic, whereby the trans'- mitted speech is rendered more audible and transmitted to a greater distance than when the usual ground or semi-metallic circuit is used.

P represents aseries ofdnpleXcontact-points 'arranged in rows in the vertical portions a of each of the sections A A A2. The number of contact-points P on each section corresponds with the number of subscribers on every other section or table. For example, section A has numbers 4, 5, 6, 7, 8, and 9, as this section can reach Nos. 1, 2, and 3 locally. Section A has numbers 1, 2, 3, 7, 8,9, and section A2 has numbers 1, 2, 3, 4, 5, 6, their own local numbers not l beingrepresentedinthecontact-pointsP. The

when the latter 1s inserted in the contactcontact-points P are provided at their upper and lower ends with separate metallic con-l tact surfaces or springs P' P". The springs P' P2 are adapted to form contacts with the metallic contact-points c7 e", respectively, of the plug c", also to securely hold the plug e point P. Each annunciator is connected with all ofthe contact-points P of the several sections bearing the same number as of the annunciator by a wire, Q, or other metallic connection, which is secured with one end to the upper conductive portion of' the switch-bar E and connected with the upper contact-surfaces, P', of the several contactpoints P.

Q represents a similar wire or metallic connection,which connects the lower contactsurfaces, P", of the contact-points P in the same manner, and which is connected to the main or` return wire L of the subscribers instrument corresponding with the annunciator with which the wire Q is connected. For instance, thewire Q is connected with the upper contactsurfaces, P,ofthe coni act-points No. 7 and with the switch-lever E of annunciator No. 7, and

the wire Q' is connected with the lower contactsurfaces,P2, of the contact-points No. 7 and with the wire or line L of subscrbers instrument No7. Thus ith'will'be seenu'l'that the -various subscribers in a central office are practicallygroupedwithin reach of each operator on each of' the sections A A' A2, whereby We dispense with the use of checks, speaking-circuits, &c., between the various operators at the central office, and whereby all unnecessary delays are obviated.

The operation of our improved system for connecting thesubscribers on one table or section with a subscriber located on any other section or table is as follows: For instance, subscriber No. 1 calls the central ofce'throngh the line o, annunciator F, line K, fingers G G', and line L, as above described. The operator raises the switch-bar E, presses the button I, loops in the listening-telephone M, and ascertains that subscriber No. 1 wants, say, No. 9. The operator again allows the switchbar E to ldrop and break the connection between the two iingers G G'. He thenturns the fingers G G' by means of the handle g3 to thedead contact-points e3 etof the disk D, and inserts the plug c? of disk No. 1 in contactpoint P No. 9 of the section A. The connection is now made with the contact-surfaces P' P2 by the metallic contact-surfaces eT e8 of the plug e, and with the fingers G G' by the wires or cords c5 e6 and contact-points e364. By thus inserting the plug e the wires Q and Q' are connected with the ngers G G', respectively. The operator now presses the battery-button N' on disk D, No. 1, which causes just sufficient vibration of the armature to release the apron f' of annunciator No. 9, thereby notifying the operator on whose table annunciator No. 9 is located that an operator on some other section desires to connect with No. 9. He therefore does not interfere, and permits subscriber No. l1 to complete his call. The operator of section A now releases the battery-button N' and presses the generator-button K on disk D No. 1, thus ringing through wire Q, finger G,to the upper contact, P', plug-contact c7, to switch-bar E of' subscribers annunciator No. 9, to the upper contact-point, o, of the same, to and through annunciator No. 9, to contact o', to fingers G G', disk No. 9, returning by wire Q' to finger G on disk D No. 1. This movement causes the apronf of subscribers annunciator No. 9 to fall also and disengage the switch-bar E, thereby disconnecting the fingers G G' on disk D No. 9, as in the *case of No. 1 subscribers first call. This movement also rings the bells on theinstruments of both subscribers, notifying them that the connection between them is completed. Subscriber No. 1 is now connected with subscriber No. 9 to and through the ICO IIO

nger G, as above described, wire e5, contact A `to the lower contact-surface, P2, of point No.

9 on section A, to the lower plug-contact, es, to wire e, to lower finger, G, to line L of the instrument of subscriber No. 1, thus completing the metallic circuit. The operators now replace the fallen aprons f f on annunciators l and 9, ready to be rung off. Any electrical disturbances-such as electric -light wires crossing the lines, lightning, or other electrical disturbances or currents which may influence the main linesufiicient to vibrate the armaturef-will be instantly turned off by the bar E moving downward and breaking the connection between the iingers G G', thus breaking the circuit, thereby insuring the system against fire.

Fig. l is a diagram showing a subscribers line No. 3 having a metallic circuit connected with subscriber7 s line No. 9 having a ground circuit. Such a connection may become necessary when the same central office has subscribers with these different circuits, or when a subscriber in one yplace having one of these circuits is connected with a subscriber in another place having a different circuit.'- As shown in Fig. 10, the lower linger, G', of the ground-circuit subscriber No. 9 is grounded. The metallic circuit of subscriber No.8 is also grounded by a ground-connection made by the lower wire, Q', as shown.

Fig. 11 is a diagram showing local connection between a subscribers line No. 8 having a metallic circuit and a subscribers line No. 9 having a ground circuit. In this case the lower contact-point, p', No. 9 is grounded on "disk D No. 8 and on any other disk on the same table on which it may appear.

The bow di constitutes the automaticallymovable contact-piece which is interposed in the central oiIice between the twc terminal points of the metallic circuit, and which completes the circuit through which the subscriber reaches the central office. This movable contact-piece, upon being automatically moved out ofits normal position, leaves the line open and ready to be connectedwith the terminal points of another metallic circuit. The operator, by calling the line which is to be connected with the calling line, opens the called line automatically, whereby the called line is made ready for, connection with the calling line. When the contact-piece d5 is in its normal position,it connects the movable terminal fingers GG of the line by means of the contact-points d3 dt, and when the line has been opened by moving the connecting-bow d5 out ot'its normal position the line is ready to be connected by the fingers G G with the terminals of another metallic circuit.

IVe claim as our inventionl. Ina switch-board system, the combinalion, with a metallic-circuit line having two contact-points connected with different portions of the line, of a movable contact-piece which connects both contact-points when in its normal position, thereby completing the circuit, and shifting mechanism, substantially as described, connected withl said contact-piece, whereby the latter is automatically separated from said contact-points by a current passing '7 3. In a switch-board system, the combination, with a metallic-circuitline, ot' a movable contact-piece which completes the circuit when in its normal position, an annunciator, and mechanism,substantially as described, where-v, by the annunciator'and the movable contact- Apiece are operated simultaneously, substantially as set forth.

4. In a switch-board system, the .combination, with a metallic-circuit line, of terminal fingers G G, contact-points d3 d, contact-piece d5, a bar, E, to which said contact-piece is attached, and mechanism, substantiallyv as described, .whereby the bar E is operated automatically, substantially as set forth. f

5. The combination, with the main line and its terminals, of a bar, E, carrying a contactpiece, d5, a movable bolt,f9, an apron, f, an armature, f5, and coils F2 F3, substantially as set forth.

6. The combination, with the main line and jfA its terminals, of a bar, E, provided with a portion, E2, carrying a contact-piece, d5, a'portion, E', carrying a contact-bow, 02, and a non-conductive portion, E3, between the portions E. and

E2, contact-pieces o o', arranged in the main line, and a locking-bolt,f, whereby thebow o'l is heldin contact with the contact -point o,

`substantially as set forth.

7. The combination, with the bar E, carrying a contact-piece, d5, of the locking-bolt f9 and an annunciator-apron, f, provided with'a lip,f7, whereby the locking-bolt is operated to release the bar E when the apron drops, substantially as set forth.

8. The combination, with the bar E, carryinga contact-piece, d 5,ofan anuunciator-apron, f. provided with a lip, f7, and a locking-bolt, f, provided with a nose,f1, whereby the drop of the apron is limited, substantially as set forth.

9. The combination, with the bar E, carrying a contact-piece, d5, and provided with a notch, F5, of a locking-bolt, f, provided with a hook, F, and a retracting-spring, fm, substantially as set forth.

l0. The combination, with theannunciatorcoil, of two aprons and an armature-lever pro, vided with locking-hooks of different lengths, whereby'one apron is released byashort movement of the lever and the other apron by a longer movement of the lever, substantially as set forth. v

11. The combination, with the annuncatorcoil, of two aprons, pivotedside by side, and an armature-lever provided with two lockinghooks of different lengths, arranged side by side, whereby one apron is released by ashort movement ot the lever and both aprons are released by a long movement of the lever, substantially as set forth.

12. The combination, with the annuneiatorcoil, of two aprons, an armature-lever provid ed with locking-hooks ol' different Length, and a battery producing a light current and a generator producing a strong current, both, ca-

pable of being connected with the annunciator coil, substantially as set forth.

13. rlhe combination, with the disk D, ofthe terminal ngers G G', secured to a noncon ductive carrier, G2, and connected, respectively, to different portions, K L, of the main line, substantially as set forth.

14.-. The combination, with the disk D, provided with a pair of through contact-points, 19 p', of separate terminal fingers, G G', connectedto different portions of the main line and adapted to be placed in contact with the points 1o p', substantially as set forth.

15. The combination, with the terminal finger G, of the stem ja, connected with the iinger G, the button I, provided with contactpoints j'jz, a stationary contact-point, m, and a listeningtelephone connected with the contact-points m and j', substantially as set forth.

16. The combination, with the terminal finger G', of the stem l, connected with said finger, the button K', provided with contactpoints Z' Z2, a stationary contact-point, mand l,

a generatorconnected with the contact-points a and Z', substantially as set forth.

17. The combination, with the separateterminal fingers G G', the battery N2, and the battery push-button 1 ofthe automatically-mov able contact-piece d5, provided with a groundconnection, d, substantially as set forth.

vided with dead contact-points e e4, of the terminal lingers G G', adapted to be placed in contact with the points c3 6*, a plug, e9, provided with two separate contact-surfaces, e7 e8, wires e5 e6, connecting said surfaces, respectively, with the points c3 e, and a contact-point, P, adapted to receive the plug c, and provided With two separate contactfsurfaces, P' P2, and conductingwires Q Q', substantially as set forth.

20. ln a switch-board system, the combination, with two or more sections, each provided with a series of duplex local contact-points and a series of duplex through contact-points, P, numbered on each section to correspondwith the local points on the other sections, and each having two contact-surfaces, P' P2, ot' wiresQ, connecting the contact-surfaces P' of the contact-points P having the same number on the several sections with the movable bar E ofthe corresponding annunciator, and wires Q', connecting the contact-surfaces P`l of` the contact-points P having` the same number on the several sections with the corresponding subscribers line, substantially as set forth.

Vitness our hands this 25th day of August, 1886.

CLAUDE C. GOULD. VALTON SMITH.

Vitnesses:

JNO. J. BoNNnn, Oscar: SGHAUB.

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