US931132A - Measured-service automatic telephone-exchange system. - Google Patents

Description

Wl W. LEAUH.

MEASURED SERVICE AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED 0G'1.15,1906.

931,132. Patented Aug. 17, 1909.

2 SHEETSSHEET 1.

w. LEAGH. MEASURED SEE-VICE AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED 00T.15,1906.

93 1 1 32. Patented Aug. 1?, 190's.

2 SHEETS-SHEET 2.

w 50:65 waaea:

. 7/z1/e 7660 r:

stop 8 may form the member-of a pair 01' I contacts 8, 9 adapted to be closed by the coin,

.Stood,. that 'other forms of coin collectors energized applies current from a generator 20 11 of the coin collector at the station of v suchline, to cause said magnet to tilt its grounded mechanism and the application of a busy example, positive current. to the limb l of the calling line, operating magnet 11 of the tilt'its armature 13 in adire'ction to remove so" 16. leading to the outside of the box. The

controlled from the calling station A. At

lector C, of a well-known type, having a line switching mechanism.

I tors a b was completed, and in addition to central office by conductors a Z and line switching mechanism of any desired type i the calling station is provided a coin colpolarized magiietll in a branch 12 from the limb 1 of the line to earth, said magnet being unresponsive to the battery at the central office. The said magnet is provided with a tilting armature 15 carrying a pair of stops '15, 8, adapted to support a coin tentatively deposited in the collector; the

and which may control. the operation of the The armature 13, when tilted in one direction, is adapted to Withdraw the stop 15 from the path of' the coin and allow the same to fall into a refund chute 16 leading to the outside of the coin collector; and when the armature is tilted in the opposite direction, it removes the stop 8 from the path of ,the coin and ermits said coin to fall into chute 17 eading to a cash box 18. It will be underthan the one shown may be equally as well employed in connection with my invention.

At the central oifice is provided a relay 19 Which receives current when the called subscriber removes his telephone from its hook in response to a call; said relay when of, for example, negative current, 'to the limb l of the calling hue and operates the magnet armature 13 in a direction to remove the stop .8 from the path of the coin, and permit said coin to fall into the chute leading to the cash box. The armature 21. of relay 19 is connected with a conductor 22 leading to the limb l of the calling line, and said armature may carry a spring member adap ted to make a momentary wiping contact with a movable contact connected with a conductor 23 leading'to the free pole of a enerator 20. In case the called line were usy, a test relay 69 would operate before the continuity of the conduccausing the restoration of the switching test to the calling line, would serve to apply current from a grounded generator of, for

coin collector, and causing said magnet to the stop 15 from the path of the coin and permit the coin to fall into iherct'und chute free pole of a grounded generator is connected Wlth a conductor 25 which leads through the armature 26 and normally-open front contacts of said test relay to the back contact of the armature 21 of relay 19. Thus when the test relay 69 is operated due to the busy condition of the called line, the armature 2(5 of said rclayin its attractive movement permits current to flow from the generator 2% over conductor 25,'armature 21 and back contact of relay 19, conductor- 22 to the limb l of the line and to earth through the magnet of the coin collector at the calling station.

The magnet 27 is adapted to be included in the ringing circuit and to respond to the ringing current therein, to eliect the connection of the generator 2% with the limb 1 ot the line to operate the magnet 11 and refund the coin. The magnet 27 is adapted in response to the ringing currcnt passing therethrough, to make and break a circuit- 28 including a source of current and the stepping and retaining magnets-of a gear 29adapted through the agency of intermediate reduction gearing to advance a .disk 30 carrying a cam 31 adapted when the disk has been advanced a predetermined distance, 90 dependent upon the time it is desired to give the called subscriber 'in whichtoanswer the call, to close a pair of contact springs 32, 33, and complete a branch 23 1 around the armature 2(3 and its front contact of relay 69. 5 Current may, now flow from the generator 24- by way of conductors 3 1, 25 and 22 to limb l of the line, to operate-the coin collector magnet and refund the coin. Said cam 31 may also a pair of contacts 35 m adapted to complete the continuity of a con ductor 36 leading from a special signal apparatus 37 to the limb 1 of thecalhng line, this'si'gnal indicating to .the calling sub scriber that the called party has failed to respond. The cam 31 may also when ad vanced the said predetermined distance, effect the restoration of the line switching mechanism; said cam may open a pair'ot' contacts controlling .the circuits of the, re- 11o taining mechanism.

Turning now to Fig. 1, I will describe in detail a telephone. exchange system equipped with improvements embodying my said invention. In said figure, two telephone lines are shown extending in limbs l, Zfrom substations A, B, respectively, to a central oflice, where each line is provided with line selecting and crn necling mechanism. I will describe in detail the circuits and apparati'ls 12o associated with the line of station A,'it

being understood that the line of station B is equipped in exactly the same manner; and

for convenience ()tdesc1'ipti( i1.I will con;

sider station A as the calling station andstation ll as the called station. r

At the substation is provided the usual .telephone apparatus in a bridge of the limbs 1 2. A. calling device 3 is provided at the substation, which may comprise a springwith a set o th EIOSIALUH opposite the d termini nctntited arm ladapted to be set in a posi tion representin the number of the line wanted, or a d t thereolf, and to be retnrned under the influence ot' a spring to operate a'gear I) to cause the same to intermittently close a pair cl contacts c 7, a number of times dependent upon the adjustment of the arm l. The arm 4 while away from normal position maintains open a pair of contact springs controlling the substation bridge of the line.

The contacts 6, 7 control tlieoperation of the central oliice line selecting mechanism, these contacts being in turn controlled by a pair of normally-open contacts 8, 9, within the coin collector U, which are closed by a coin when tentatively deposited by a subscriber. The contact spring 7 is connected to earth, and the contact spring is con nected with a conductor ll) which leads throu 'h contacts 8, 9, within the collector, to the limb ot'. the line.

it: the central office, the limbs l 2 of the hi0 m y-pass through the arniatures c 0, respectively, of a cubotl relay (1, to the con- .cts 134, 3."), upon the rotatable selector arm iinb 2 extending; through a conno, the l denser, at nature 37 and its norm front contact of relay 38, through. the armature 39 and back contact of relay at), to the. selector contact 5135, while the limb 1 extends through a condenser, armature 41 and back contact of relay 40, to the conact 34-.

The third. terminal 412 upon the selector arm is connected with a conductor 4-3 lead- .i through the winding of relay 38 to ground, Said relay 38 beingpreferably gish in its action, The contact arin so "m red to sweep orcr terminals, which my be connected directly with telephone nes, or with trunk lines leading to other selectingr l'ilt'it'lltll'llhlll. in the present case, for convenience o'l' ties ription and i lustration. l have shown thrltt'illlllftlS as representing: telephone lines. that is, each line is provided three terminals, tern'iinal i -l being; connected with the limb 1 ol the line, while the tc h the ally-open mail to is connected w t limb 2 oi the me The local terminal 4-6 oi h s t connected with the conductor 7,

ich leads through the cut-oil" relay w to the rec pole or grouruled battery ltv. The limbs are, of course, multiplied to contacts upon the different selectors S in the eX- change.

Tl lcctor arm 36 may be mounted upon l rotary shaft 49 provided with l apled to be engaged by a stcp- Til operated by an clcctrotnannet ratchet l t-inn" provided. with a rer by a n'iugi'iet i li n ha; been moved to, esired Pet of line a magnet 55 is arranged to force selector 1 l I l l l l l l l l the shaft ll) downwardly and bringthe con lacls upon the selector arm into engagement \Yllll the desired line terminals.

Jr relay 5b, which controls the 1 ing mechanism, in prox'ided in a bridge of the limbs l 2 of the line, said bridge also including" a battery 56, having its negative pale grounded, and a relay 50, said battery being interposed between the relays it; ill), with its; positive or tree pole connected with the limb 2 of the line. lrhcn the telephone is'rcmovcd from its hook t the calling station A, a circuit is completed by way ol the bridge 57 and limbs 12 for the relays Mi iii), and current also tlows from the tree pole of battery 58 through bridge 57, limb 2 ol the line, through the snbstation bridge closed by the telephone switch so, to limb l of the line, and thence to earth through branch 12.

inc selcetwhich includes the elcctromagnet oi the coin ,ture of the storming magnet n its up collector. The airrent from the said central otlice battery does not all cct the magnet ll of the coin collector,

The relay 5:6 provided with a si a mature (31, which is adapted when it ed to close a shunt (32 about the cut-oil relay (l of the calling line, ,to pit-rent. its improper actuation if such line should be n' lected and tested by another line during; the conversation.

Linc selecting operation.-"he armature (53 of relay 56 controls the circuits of the line selecting mechanism, the armature being connected with the coi'iductor (i l, which extends to the :lrce pole oi? battery 5R, while the front contact of said armature is connected with a conductor or, which leads thronrh the retaining magnet 54 and stepping magnet F2 in series, hrou 'h normally closed contacts so ()7 controlled by relay 5: through the aianature as and back contact of busy test relay (if), to earll A branch con doctor TO leada from conductor throu h the winding oi eonncrting magnet air, through a pair of contacts [1, which are intermittcntly made and ln'oken by the arma oration, back to the conductor of). F uid coularls T1 are arranged to prevent, while being rapidly made and broken. the cnergizalion of the connecting nnigrnct 55, but when allowed to come to rest to permit vqullicient current to flow to operate the magnet 55. Tl-hc ma 55h provided with an armature T52 connected by a conductor 73 with the said conductor 7J0. :t w'aid armature, when attracted, forces; the shalt 4-9 downwardly, and engages spring (37 to separate the same tron: its an il 66, to thereby complete a circuit for magnet 55'independent of the contacts 71. inn subscriber at station A, call, deposits a coinin the collector which falls illpon the stops l5 ,8, closing the contacts 8 9. He thereupon operates the calling tlevice to make and break the contacts 6 7 a lhe call-, 7 1n mutating 'a l. l. O

predetermined number of times, dependent upon the number of the line desired, and a circuit, is intermittently made and broken for the relay 56 at the central office, said circuit extending from the free pole of battery 58, through relay 56, bridgt 7, limb 2 of the line, contacts 8 9 clos'. by the coin, through the contacts 6 7 of the calling device. Relay 56, in vibratinggi't s armature 63', iinierinittently makes and breaks a circuit extending from the free pole of battery 58, conductors 64 and 65, through retaining magnet 5st, and stepping magnet 52, through the springs 66 67, armature 6S and back contact of busy test relay 69 to earth. The re- 1 taining magnet 54 is operated to throw the' pawl into engagement with the ratchet 50, and also the stepping magnet 52 operates to rotate the shaft 49 and bring the select-or arm into position opposite or over the' set of terminals representing the line desired.

lVhen the'contact arm 4 of the calling device returnsto normal position, after operating contacts 6 7, it closes" again the metallic circuit ofthe limbs l 2, maintaining the relays 56 59 energized, and current flows from the tree pole of grounded battery 58through conductors 64- 65 70, through connecting magnet 55, contacts 71, which are now at rest, back to .conductor 65 and thence to earth through the armature 68 and back contact of relay 69. Sufficient current now flows in this circuit to operate the connecting magnet which attracts its armature 172, forcing the sl'ia't't L9 downwardly, and bringing the terminals 3% 35 4.2 into engagemcnt with the terminals 45 44' 46 representing the called line. The armature 72 also engages contact spring 67, to separate the same from its anvil 66, and completes'a circuit :trom conductor 65 through the connecting magnet 55, conductor 70, conductor 73,

armature 72 of relay 55, and contact spring 67, back to conductor 65, and to earth independent of the contacts 71.

Test of called lim -'llheiimb 2 of the line is normally open at the armature 37 and front contact 0 t sluggish relay 38, which is included in the circuit above traced, and a testing conductor extendst'rom the ter-- minal 35 upon the selector arm, through the limb 2 of the line, to the armature 37 of relay 33. whose had: contact 1s connected with a conductor 74 leading through a winding 75 of the busy test relay to earth. In case the called line is busy there will be potential upon the terminal 44 from the central otfice battery 58uby way of the substation of the line, and current will flow through the testing conductor and winding of the test relay 69 to earth and energiie said'relaybefore the sluggish relay 38 has had time to respond to the current in the local cir uit 47 43, The relay 68 when thus energize attracts its armature 68, opening the circuit 64 65-5 70-73-65 of the connecting magnet 55, and allowing'the selector mechanism to be restored to normal condition by means of a suitable spring. ",Said relay 69 is also providedwith an"a"rmature 76, which is connected with a conductor 77 leading to the front contact of an armature 78 of relay 56,

said armature 78 being connected with the their initial attractive movement, current flows from the free pole of grounded battery 82 through the winding of said relay, armature 78 and front contact of said relay 56 to limb l of the line, and thenceby way of bridge 57 to earth, locking up the relay 69, whereupon busy test current is applied to'the line, said current flowing from the secondary winding in conductor 7 9, throu h conductor 77, limb 1 of the line, through tie substation apparatus, limb 2 of the line, bridge 57, to earth. The subscriber, upon hearing the busy tone in his telephone, hangs up his receiver 56, which retracts its armatures, the armature 7 8. opening the locking circuit of the busy tone relay 69 and restoring the same to normal position.

, Refund of 002% where called partys line is bus3 .-The relay 69, which operates when the called line is busy, .is provided with an armature 26, adapted when attracted to complete the connection of positive genera,- tor 24: with the limb 1 of the line, by way of conductors 25, 22. Current from the positive generator 24 now flows to'ear'th through the winding of the electromagnet 11 of the coin collector, operating the stud magnet and causing the same to tilt its armature 13 in a direction to throw the coin into the refund chute 16.

(J'alla'ag a free Zinc w/zere subscriber (mswcra-lrtthe present condition, when the contacts upon the selector rest in engagement with the terminals of the called line, there is and cuts off the conductor 7 4, which includes the winding 75 of the test relay, from the limb 2 ot'the line, at the same time complet ing the continuity of said limb. The relay 38 is provided with an arnmture 83 which is connected to ground, the front contact of said armature being connected with a conductor 8% which leads through the relay 4:0 to the free pole of-a grounded battery 85, and said relay 38, when attracted, in case the duct called line in free, ceinpletes r circuit to p crate relay 20, which thcreu 'mn attracts i'ls arn ur 1 31 -fl-l., wh. t' l c -utaci's turn the terminals cl conductor :3 including u. ringing generator 87 and the w ling 88 0f a relay an. 'lfh w, when the y l-t is en ,cd. ringing ci rent flex iron] the upper pole, for example. of the generator T through the armature ll and front cci ol re ll line conductor l cnnia 1 upcn tnc selector; liinb 2 cl? ihe callc thencc throng h the hell at t 1 substation of the L'Zlllill line, back over limb l at the called line, thrcugh the cunt ts H cf the hector. liinb 1 cl thc calling line arniatn 39 and front cnntzwt of relay ell), through the windin $8 cl? the i i Sf), in the lower pole of lhc cnc'alor The relay is arranged to la unr nneivc to the current llowing in the circuit just traced, owiir the high 1' Itancc in the line at the sub tiun, l 1 l ilic called sulb ,riber respon c. by renamin his telephone trein its heck, a shunt is established about the ln'i containing the bell and condenser at the sub-- ergize ihc in" its arriaturi arniaturc fltl nil net 89 sutlicie in attract y le iii-(int contact 0i. relay 89 in included in; a con- .ll which leads from ihc free pole of {,{ltlililnttl miter lhruugh a lbw rc cn e '.\'i-' ling 9; cl rel FM, while the urinalure fi l! l. L =nncctcd 1th a cmuluclor h which lcudu threw ac armature ill and ..i tn the bridge 57- lrnnl. contact c-l' clay and earth. The conductors ill, 93 and 57 act as a shunt abcut relay L0, to czluere the same to retract its arniiiturcs 39, 4- and break the rii ing circuit above t 'acedl the rilay 55f being; ed up by me f winding J9,

included in said shurn 1g circuit. A bridge 535 of the limbs l" 2 (If the line is provided between the condensers and the contacts upon the selector. said bridge containing a 3 impedan e coils to fur-- Jill-ll the talhing "l'l'tlliT required by the called v talicn for iranz-zuiis ri n purpnsen. 'lhc al'nnilul'c ill of relay S9 is connected by cnnductcr .22 with linib l of the calling; line, and l'w' adapted in attracting tn ccinplelc n10- ccn between a pair of wiping CUllLdC lS tn cuni'icct the coxuliurtcr 23 including grounded n ative generator 20 with conductor :22 and limb L A momentary inipulse 0i current from mid generator new flows tn earth through il e magnet ll of the cuin' collector, uperatin said ma mauve the same in till i fully f0 HH "l'/ 'in; circuit in ii cpcratcs lhc in anian and ung inc d usually are, one and the e I a: answer e ici its )i' 1 these i an Sznnc.

t will be lllitltfin'iOUtl, that while *lcr c0nicnce of illustratinn and description, I have shown an clnbcdinient cl my invention applied to :1 small system, the inrcntien may be cqu applicable to many cihcr wctezns, hnili lar and Hun-ill; and l do not deche to y be 11 i need an limiting the application of my inrcntinn to any particular antoniai-ic i'clcphunc exchange i 'liein.

che coinhinatien with a, calling and 21 called tclej'ihcnc line extending from sub nil (0113 to a central ntl'ice, of a coin ccllectur is at the n. station of the calling line ha ing a coin cnnlmllcd magnet cnnneclcd with and line, automatic line switching niccluinisi'n in said cullcclnr, 'l ur unilin mid linen, gcncralnr at the central nil" For operating said mail-Such a stance of riu 'ing current, incurs auton itically operated upon the conncctmn of 51 lines for applying said ring ing current to the called linc a relay in said ringing circuit unresponsive to said current while lhc normal high rcsi'tance is included in the called line at {he etatinn thereof. said Mela-3' rcspnnrjling when 5 id resistance is shuntml by ihc rcium'al (it the ralled subscribcrs tclcphnnc. and means controlled by 1 said relay lnr cnnnccling' anid gcucratnr with 'llu called line.

2. The cnnibiuaiimi with a calling and a mulled telephone line extending lrnui nub stations te a ccnt ml zil'licm at a will collcc'tor at tlu; -:ub-:t the culling line having a min cmilrol c l n 'ccenncctcd with said line automatic line switching; mechanism upon lh'c tentative deposit cl a coin in said ccitector, l m uniting said lines, a generator at the central nllicc for up; 'atii'ig said nuvmct a lOillCt. cl ringing current, inc-ans antmnal r l; nperaled upon the mnncctiun nl rid lllliln *lur a; plying said ringing currcni in the called lino a relay in said ringing; rircnil unresponsive tn Silltl current while the nurnial high resistance is included in thc called line at, lhc rslatinn til cruel, vaaid rclar r spending when uaid ,uhuntcd out by the l'LHH/Vill cl llic called l we rabl npcu the tentative deposit 01' a cuin subscribers telephone, means controlled by ,said relay for connecting said generator with The combination with a callingand a.

called telephone line extending from substations to a central office, of a coin collector atthe substation of the calling line having a coin controlled magnet connected with said line, automatic line switching mechanism operable upon the tentative deposit of a coin in said collector, for uniting said lines, a generator at the central oflice for operating paid magnet, a source of ringing current, means automatically operated upon the connection of said lines for applying said ringing current to the called line, a relay in said ringing circuit unresponsive to said ringing current while the normal high resistance is included in the called line at the station thereof, said relay responding when said resistance is shunted out by the removal of the called subscribers telephone, and a pair of wiping contacts operated by said relay in responding to connect said generator momentarily with the calling line.

Jr. The combination with a calling and a called telephone line, of a coin collector associated with the calling line at the station thereof, automatic line switching mechanism, operable upon the tentative deposit of a coin in said collector, for completing the connection of said lines, and means automatically operated in case said line is busy, for operating said coin collector to refund said coin.

5. The combination with a calling and it called telephone line, of a coin collector associated with the calling line at the station thereof, automatic line switching mechanism, operable from the calling station, upon the tentative deposit of a coin in said collector, for connecting said lines, a test relay operated in case the called line is busy, and means controlled by said relay for operating said coin collector to refund said coin.

G. The combination with a calling and a called telephone line, of a'coin collector at thecalling station having a coin-distributing magnet connected with the line, automatic line switching mechanism, operable from the calling station upon the tentative deposit of a, coin in said collector, for connecting said lines, a test relay, a circuit therefor completed in case the called line is busy, a source of current adapted to operate said magnet to refund said coin, and means controlled by said test relay for connecting said source of current with said calling line.

7. The combination with a calling and a called telephone line extending from substations to a central office, of a coin collector at. the calling station, automatic line switching mechanism at the central oflice, operable from the calling station upon the tentative deposit of a coin in said collector, for uniting said lines, a busy signal apparatus auto matically applied to the calling line in case the called line is busy, and means controlled by said busy signal apparatus in operating, adapted to actuate said coin collector and refund said coin.

S. The combination with a calling and it called telephone line extending from sub stations to a central OlllCB, of a coin collector,

at the calling station, automatic line switching mechan sm at the central otlice, operable from the calling station upon the tentative deposit of a coin in said collector, for unit ing said lines, a busy signal apparatus automatically applied to the calling line in case.

the called line is busy, and means controlled by said busy signal apparatus in operating, adapted to actuate said coin collector nd refund said coin, and means controlled by said busy signal apparatus, for resfiorin said line switching mechanism to norma condition.

t). The combination with a calling and a called telephone line extending from substations to a central otlice, of a coin .collector at the calling station having a polarized coindistributing magnet.- connected with the line, autoi'natic line switching mechanism,- oper; able from the calling station upon the tentative deposit of a coin in said collector, for connecting said lines, sources of current of opposite polarity at the central ofiice, means, automatically operated in case the called subscriber answers, for connectingone of said sources with the calling line to operate said magnet and finally deposit said coin, and means, automatically operated in case the called subscribers line is busy, for connecting said other source of current with the calling line to operate said magnet and refund said coin.

10. The combination with a calling and :1 called telephone line extending from substations to a central office, of a coin collector at the calling station having a polarized coin-distributing magnet connected with the line, automatic line switching mechanism,

operable from the calling station upon the tentative deposit of a coin in said collector, for connecting said lines, sources of current of opposite polarity at the central'oifice, a

called telephone line, of a toll device associated with the calling line at the substation there-of, automatic line switching mechanism, operable upon the tentative actuation of said toll device, for completing the connec tion of said lines, and means, automatically operated, in case the called subscriber fails to respond to the call,.l'or restoring said toll device to norm condition Without placing said calling party to expense.

12. The combination with a calling and a called telephone line extending from substations to a central ollice, of a toll device associated with the ailing line at the substation thereof, tltltOlIltllfiC line switching mechanism, operable upon the tentative actuation of said toll device, for completing the connection of said lines, means, automatically operated, in case the called subscriber fails to respond to the call, for restoring said toll device to nor mal condition Without placing said calling partly to expense, and means automatically operated upon the response of the called subscriber for operating said toll device to place the calling subscriber at expense.

The combination With a calling and a called telephone line extendingfrom substations to a central ol lice, of a toll device associated with the calling line at the substation thcreoit', automatic line switching mechanism, operable upon the tentative actuation of said toll device, for completing the connection of said lines, means, automatically operated, in case the called subscriber fails to respond to the all, for restoring said toll device to normal condition Without placing the said calling party to expense, and means, automatically-operated upon the response of the called subscriber, for operating said toll device to place the calling subscriber at expense, and means, autoinatically-actuated in case the called line is busy, for' operating said toll device without placing said calling subscriber to expense.

1%. The combination with a calling and. a called telephone line extending from substations to a central oltice, of a coin collector at the substation of the calling line, automatic line switching mechanism, operable upon the tentative deposit of a coin in said collector,

tor cim'ipleting the connection of said lines,

and means, automatically operated in case the called subscriber fails to respond alter a predetermined period, for operating said coin collector to refund said coin.

15. T he combination with a calling and a called telephone line extending from substations to a central otiicc, ot' a coin collector at the substation ot' the calling line, automatic lino switching mechanism, operable upon the tentative deposit of a coin in said collector, for completing the connection of said lines, means tor automatically applying ringing current to the called line upon the complel l i l l l l l i l l l i l i i l l l l l lion ot'conncction therewith, and means, antomatically operated, in case the called subscriber tails to respond after said ringing current is applied apredeicrinined period, for operating said coin collector to refund said coin.

16. The (fOi'lilJilllit'lOll with a calling and a called telephone line extending from sul'istations to a central ollicc, of a coin collector at the substation oil the called line, automatic line switching mechanism, operable upon the tentative deposit of a coin in said collector, for completing the connection of said lines, means for applying ringing current to the called line, stepping mechanism operated by said ringing current, and means ope 'ated by said stopping mechanism after a product'- mined period, for operating said coin collector to refund said coin.

l7. The combinationwith a calling and a called telephone line extending from substz tions to a central oilice, of a coin collector at the calling station having a coin-distributing magnet connected with the line, automatic line switching mechanism, operable from the calling station, upon the tentative deposit ofa coin in said collector, for connecting said lines, a source of current at the central otlice adapted to operate said magnetto refund said coin. and means, automatically operated in case the called subscriber fails to respond, for connecting said the calling line.

l8. The combination with a calling and a called telephone line extending from substations to a central otllce, of a coin collector at the calling station having a coin-distributing magnet connected with the line, automatic line switching mechanism, operable from the calling station, upon the tentative deposit of a coin in said collector for connecting said lines, a source of current at the central oilice adapted to operate said magnet to refund said coin, means for applying ringing current to the called line, a relay in said ringing circuit, and means operated by said relay alter the called subscriber has been rung a predetermined peli iod and fails to answer, adapted to connect said source of current u'ith the calling line.

19. The combination with a calling and a called telephone line extending from su ations to a central olllcc, of a coin collector at the calling station having a coin-distributing magnet connected with the line, automatic line switching mechanism, operable from the calling station, upon the tentative deposit of a coin in said collector, for connecting said lines, a source ot. current at the central ofiicc adapted to operate said magnet to refund said coin, means for applying ri-nging curv rent to the called line, a relay in said ringing circuit responsive to said ringing current, and electromagnetic stepping mechanism on source of current with erated by said relay, said mechanism being adapted when ringing current has been applied to the called line a predetermined period, to connect s aid source of current with the calling line.

Q0. The combination with a calling and a *alled telephone line extending from substations to a central office, of a coin collector at the calling station having a coin-distributing magnet connected with the line, automatic line switching mechanism, operable from the calling station, upon the tentative deposit of a coin in said collector, for connecting said lines, a source of current at the central office adapted to operate said magnet to refund said coin, means for automatically applying ringing current to the called line upon the completion of connection therewith, a relay in said ringing circuit, a circuit closing device, stepping mechanism therefor, operating magnets for said mechanism, a circuit for said magnets intermittently made and broken by said relay, and a connection of the said source with the calling line completed by said circuit closing device when advanced a predetermined distance.

21. The combination with a calling and a called telephone line, of a toll device associ- .ated with the calling line at the substation thereof, automatic line switching mechanism, operable upon the tentative actuation of said toll device, for completing the connection of said lines, and means, automatically operated, in case the called subscriber fails to respond to the call, for restoring said toll device to normal condition without placing said calling party to expense, and a characteristic signal applied to the calling line in case said called party fails to respond.

22. The combination with a calling and a called telephone line, oi? a toll device associated with the calling line at the substation thereof, automatic line switching mechanism, operable upon the tentative actuation of said tolldevice, for completing the connection of said lines, and means automatically operated, in case the called subscriber fails to respond to the call for restoring said toll device to normal condition without placing said calling party to expense, and means actuated upon, the failure of said called party to respond, for restoring said switching mechanism to normal condition.

23. The combination with a calling and a called telephone line extending from substations to a central office, of a coin collector at the substation of the calling line, a coindistrilouting magnet for said coin collector connected with the calling line, automatic line switching mechanism at the central oilicc for completing connection between said lines, means at the central oflice for actuating said "coin collector magnet to deposit a coin tentatively. deposited therein, and means at said central oilice for actuating said magnet to refund said coin.

it. The combination with a calling and a called telephone line extcndii'ig from substations to a central ollice, ot a. coin collector at the substation of the calling line. a polarized coin-distributing elcctromagnct for said coin-collector connected with the 'alling line. automatic line switching mechanism at the central ol'lice for completing the connection of said lines, sources of current at the central ollice of opposite polarity, means at the central ()l'lltit' 'i'or applying current from one of said sources to the calling line to actuate said magnet and deposit a coin tentatively deposited in said collector, and means at said central oitice for applying current from said other source to the calling line to actuate said magnet and refund said coin.

25. The combination with a calling and a called telephone line extending from substations to a central otlicc, ot a coin collector at the substation of the calling line, a coindistributing electromagnet for said collector connected with the calling line, automatic line switching l'nechanism at the central ollice, operable upon the tentative deposit of ,a coin in said collector, for completing connection between said lines, means at the central oliice for actuating said magnet, in case the called party responds, to deposit said coin, and means at said central ol'lice for actuating said magnet, in case connection cannot be had with the called party, to refund said coin.

iii. The combination with a calling and a called telephone line extending from substations to a central ollicc, oi a coin collector at the substation ot the calling line, a coindistributing electromagnet for said collector connected with the calling line, automatic line switching mechanism at the central ofiice, operable upon the tentative deposit of a coin in said collector, for completing connection between said lines, means at the central otlice tor actuating said magnet, in case the called party responds, to deposit said coin, and mechanism at said central oliice, autonuitically operated in case the called party fails to answer, or his line is busy, for actuating said magnet to refund said coin.

27. The combination with a calling and a called telephone line extending from substations to a central ollice, of a coin collector at the substation o the calling line, a polarized coin distributing clectromagnet for said coin collector connected .wilh the calling line, automatic line switching mechanism at the central oliicc for completing connections between said line utter the tentative deposit of a coin in said collector, sources of current of opposite polarity at the cent 'al ollice, au-

tomatic mechanism at the central otlice, operscrlber,

for applying curent from one of means for applying current from said other source to the calling line to actua'iia magnet and refund said coin.

In witness whe eo'f, EI hal e-unto subscribe my name this 13th (lay of October 1 D,

Images