US1714718A - A cobfosation of dela - Google Patents

Description

May 28, 1929. R. MERCER TELEPHONE SYSTEM Filed Oct 31, 1924 6 Sheets-Sheet l Numb f/vl/mm/a/F/mA/F Mman 4%. 1 W

May 28, 1929. MERCER 1,714,718

TELEPHONE SYSTEM Filed Oct. 51, 1924 6 Sheets-Sheet 2 f/VVt'NTUR- Emmi/F0 M59052.

444/2. MATT}! May 28, 1929. R, MERGE R 1,714,718

1 TELEPHONE SY/STEM Filed Oct. 51, 1924 s Sheets- Sheet s I36. I35 hh 312m.

I 56.5. I IN I I.

May 28, 1929. MERQER 1,714,718

TELEPHONE SYSTEM Filed Oct. 31, 1924 e Sheets-Sheet 5 Ill) Patented May 28, 1929.

ear "r I I lanai RICHARD MERGER, or EABROW, ENGLAND, ss reivon, 'BY MESNE assromannrs, To

auronarrcnrncrnrc nc, or CHICAGO, tumors, s CORPORATION or DELA- j WARE,

TELEPHONE SYSTEM.

- Application file l October 31, 1924, Serial No. 746,992, and in Great BritainN'ovemher 6, 1923.

The present invention relates to improvements in or relating to automatic telephone systems and more particularly concerns thegeneral lay-out otthe apparatus used-1n connection with such systems. For some time it has beenzrealized that certain controlling apparatus of an expensive nature-could only be afforded to be linked up to a connection temporarily so that the apparatus would be provided in a small quantity less in quantity,

than the number of apparatus simultaneous lyjin use with which apparatus'they are adapted to be associated; This particularly applies to ,i'egisters or registering translating devices, but it also applies to the case where special facilities require to bep'ro-- vided, such as zone metering and inter-ofice trunking; other arrangements have probably also been contemplated but'have not become I A I"v possible'be'cause .oi the fact that "the cost or tie a'pparatuafinder switches or the like which temporarily associates the apparatus with the switches used in setting up a connection more than compensates for the saving effected. At thesame time it has been usual tion, thereby necessitating the provision of a number or relays, sequence switches, sideswitchesor the like permanently associated with the switch for the purpose'el eliecting the control of the various operating magnets, clutch magnets or the like. Broadly speaking the princ' Sal vention cons such permanently associatedcontrolling ap-' paratus which is only essential for the setting up of the connection By these meansnot only can the cost of the temporarily associated apparatus be compensated, but actually a saving may be effected in the actual cost of apparatus used in an exchange while further additional facilities could be readily added at; comparatively small expense. While the invention is applicable to the various types er switches used in connection with automatic telephony, forinstance power drivenswitchesor step by step switches and in certain casesto relay switches, it will be described in connection with a well known system employing two directional-switches feature of the presentin-- J in the elimination oi all ciated with each two-directional switch,

which relays although connected in permanent association therewith, are only used actually during the transmission of impulses, so that their useful life is very smallindeed. Such-relays naturally have a life far exceeding the life of the switch with which they are associated, and therefore are, comparatively speaking, expensive for their use, and asthe cost of a relay is a small but important percentage of the cost of the switch itself, it will .be appreciated that the cost of each switch is unduly increased by having such relays permanently connected to them.

The invention in addition to the production of a more economical system also effects the simplification of the switches so that the switcii becomes an'iechanical construction almostentirely' and can be used for different purposes or in different relative positions in the setting up of a connection without any alteration in its circuit or constructional details. One advantage of this arrangement is that the maintenance of the switches is almost entirely mechanical and not a combina tion ofa relaymaintenance with mechanism 'n'iaintenance which has hitherto been essens tial. Again, by providing for the controlling relaysto be common to a plurality oi switches, other auxiliary apparatus for special purposes, such as zone metering, interexclrngc routing or satellite working may be provided very economically.

Another object of the invention is the modification of the switching'layout and the use of switches for'two or" more purposes which becomes readily possible when the operation of the switches is controlled from an auxiliary path.

One of the features tion is the provision in addition to the switches used throughout a connection of an auxiliary set of switches orsteering appara tus taken into use only during the setting up of a connection and adapted to control the of the present invenoperation of the switches in the speaking" routeindividually, for instance, when employing switches of the step byjstep type having movementin two directions, the magnets are controlled over circuits leading direct from the steering apparatus which may V the setting route establishes connection to the controlling oroperating magnets of the same switch. The steering apparatus in addition includes switching means by which the operating impulses may be transmitted over different paths to or from the diii'erent con trolling magnets.

1 In the large system it may be desirable to provide additional steerer devices in addition to those adapted to be first taken into use, so that the control of the switchesin establishing a connection may be controlled partly through one steering device and partly through another.

Another feature of the present invention which becomes possible byemploying the foregoing is a switch in which the wipers are connected permanently to the incoming leads. Such a switch may be used for different purposes such as talking, testing, trunk offering or the like, or again it may be used bothv as a connector and as a finder switch, depending upon the route over which it is taken into use, no alteration however being necessary in the switch itself. The operating magnets are controlled over a means of access separate from the talking conductors including the wipers of an auxiliary switch temporarily associated therewith; this applies not only to the impulse controlled magnets in a group selector or connector switch, but applies also to the hunting magnets of a group selector. In order to enable a'wanted subscribefs line to be tested while keeping the switches guard- "ed from outside interference. two separate test leads are provided which are disconnected durin the setting of the switch until it) o p the test has been made.

A further feature of the invention which also arises out of the foregoing is a novel arrangement for connecting the calling subscriber to the first numerical switch. For maximum economy it is desirable that the steering apparatus should serve as large a group ofsubscribers as possible in order that the number of suchapparatus should be small and further that the number to each group should be sufficiently great so as to ensure satisfactory working if one should be out of action for any reason. To attainthis result it is desirable to arrange that the calling subscriber should beconnected up in a similar manner and by similars 'itches as the called subscriber is connected up, from a centrl the talking route, two courses might be adopt- .ed, one to use a finder switchpreferably of small capacity to find the calling line and ar-.

range for the simultaneous operation of a hunting switch linked to the finder switch to find an idle StG1G1,.OI a small relay preselector in conjunction with a secondary line switch may be used; the relative advantages of the two arrangements depend upon the traflic conditions. Ineither case an impulse sender is controlled in such a manner as to send impulses corresponding to the number of the calling party to control the switches which establish connection to the calling line in the same manner as the switcheswhich establish connection to the called line. The steer-er is arranged to preselect an idle trunk relay group, while the connection to the call-- ing line, as well as to the called, line is over switches in serial relationship switches having a capacity of 100 lines the steerers are therefore provided. common to a group of 1000 lines. It may however be necessary to provide twoor three groups of With steerers per 1000 lines if the traffic conditions 1 appear to warrant this; in which case all the.

switches in the exchange would be divided into slmilar groups. Means for arranging that the steerers or impulse senders have access to gradually increasing groups of lines can be provided, as will be readily under- While stood by those versedinthe art.

'the inventionv can be readily applied to any size systeimfor the sake of simplicity a description will only'be given of a 10000 liueexchange of the simplest type, from which the above and other features of the invention will be understood.

The invention willbe better understood by referring to the accompanying drawings which illustrate one manner of carrying the invention into effec applied to a 10,000 line exchange, wlthout providlng facilities for' P. B. X. line selection. J

Figure 1 gives a general layout of the novel system while Figures 28 givev detailed circuit diagrams of the line circuit, connector finder circuit,trunk relays with finder and group selector switches, main steer-er, subsidiary steerer, connector finder selector and a second connector finder cireuitrespectively, which whenplaced in positions corresponding to the arrangement of Figure 1,

enable the operation of setting up acall from one subscriber to another to be followed.

Referring to Figure 1 a brief description describing the general' outline of the system will be given. The trunk relaysTR are provided in groups to dealwith the traffic of 1000 subscribers lines and comprise battery feed, holding, switching, busy back and ringingrelays and are the only relays which are ten groups of combination connector finders such as C1 1 wlnch are also two'directienal step by step switches and are adapted to be operated to establish connectionwith both a calling and a called line. lhe first selectors have access to second selectors such as SF S sw tches is controlled infsynchronism; but 1 which in turn have access'to connect-or finders such as C1 1 or SE2. All the switches CPS;

C1 1 and C1 2 are two directional switches having no interruption in ,the'connection' of their incoming andoutgoing wiper connections. In addition here is a group of main steerers t'oreaeh group of trunk relays and a group of subsidiary steerers for each group of second selectors. The main steerers are selected by main stecrer selectors MSS individual to two outlets selected by relays ltl, B2 individual to a subscribefis line; main steerers MS comprise a group of relays; three steer-er switches SS1, SS2, SS3 all which are of the two directional type and atrunk finder TF. SS1 controls the rotary movement of FS and connects up the magnets of CF13 SS2 controls the rotary movement of GS and connects up the magnets of CFS. SS3 connects up asubsidiary steerer SS which includes a group'ot', relays and a steer switch The steer switch SS controls the rotary 1n vement of CF S and connects up the magnets of CF2 In brief theoperation is as follows: V I

'rrssunnng subscrioer do; 9854: w "hes to subscriber Not 7623-, he lifts his l3'@l '1' and relay R1 operatesand it. the first outlet is busyR2-also operates and selects themain,

steerer selector which rotates to find an idle main steercr MS wlnch arranged to be in engagement with an idle TR, over the finder roup of trunk rel y switch TF- 7 Impulsetransmissionthen begins. Relay s,

and control the operation of an impulse sender to send outthe last three digits of the'calling sunscribers number, namely 65 i, wliile,tpossioly atthe same time; the subseriber'operans his llllptllSQ sender to send out the number 7 621%.- r'l a'lringthe first mentioned operation thefirst- SlX mrp ulses are" arranged to control tical magnets 0*; ES and SS1 so that ho connection.

are operation of the ver- SS1 and cause the wipers of CF 1 tostep up to the fourth contact of the fifth level to which the calling partys line is connected.

Meanwhile the impulses generated by the calling party cause the switches GS, SS2 and SS3 to step up to the seventh level. The rotary magnets of SS and SS2 are operated in synchronisin until SS2 finds an idle second selector switch CFS so that GS establishes connection to the wipers at the same time as connects up themagnets of CFS. SS3 hunts in the usual way to find an idle subsidiary steerer SS. The next series of impulses (6) causes CBS and SS4 to step to the sixth level when both rotate in synchronism until SSl finds an idle connector CF2 so that CF S connects up the wipers of CF52 while SS4 connects up its magnets. The next two series of impulses (23) step the connector GF2 up to the third contact of the second level to which .as the subsidiary steerer and the associated switchesSSl, SS2, SS3 and SS4. 'TF operates to preselect an idle trunk and the relays B1, B2 are released to connect up the callingline to the contacts of CF 1 so completing the s it should be noted. that as the main steerer is only in use during the period of setting up a connection the switches MSS need only be provided at a rate of about two for25 to lines. Approximately 9-11 main "steerers MS would be required per 1000 lines while the subsidiary steerers would be in the same proportion. In View of the large group'ot subscrlbers (1000) accessible to TB, the number of first selectors would be of the order of from 550 to 650. The cost compared with the use of line switches is reduced, whilea considerable saving is the elimination of a large numher. of relays performing a very limited function. Again the switches become mecha nisms purelyand simply, and no longer a complicated circuit arrangement in addition,

thus facilitatingmaintenance. v

The mam steerer and subsidiary steerer although comprising a number of relays need not beconsidered'very complicated as they canconyeniently he -divided into clearl 1 dc fined groups of counting relays and replacement of any particular group would be a-very simple matter. Having described the general arrangement, a description Wlll new be given of the .circults used for setting up a call.

r conductor 16 of the switch MSS whichwould be the case if the first switch was busy, as relay 13 will be short circuited. If the first switch is busy relay B1 on energizing prepares acircuit for relay R2 as follows: earth, contacts 11, 17 and 18, relay R2 to battery. Relay R2 energizes and assuming the second switch MSS to be idle and no earth on test conductor 19, relay 13 will be no longer short circuited but will energize in series with re sistance 20 and battery. If both switches MSS are busy, contacts 49 and will be both open so that the line relay cannot energize until one is free. This would only be rare occurrence as the group of subscribers lines is small, and if it happened would last for only a very short interval of time. Assuming however that the first switch is free, relay 13 will energize immediately and open the circuit of .relay 10 at 51 and 52, so that this relay falls away shortly after, opens contacts 21 and 18,.and closes contacts 22 and 23, thereby completing the following circuit for relay 24: earth, contacts 25, 26, 27, 22, subscribers loop,.- contacts 23, 28, 29, 30, relay 24, battery. Relay 24 energizes and connects earth to test conductor 16 at contact Relay R1 is V locked up to the test conductor 16 as follows'z earth on conductor'16, 15, 32, relay R1, to battery. J Relay n1 maintains relay 13 energized over contact 34. All these holding circuits are completed before relay 10 falls away.

Relay 24 at contact 36 completes a circuit for relay 37 in series with. stepping magnet 38 while at 39 the test wiper 40 is connected,

to thejunction point so that the stepping magnet is operated until an idle main steerer MS is found. When this occurs relay 37, which is no longer short-circuited operates and disconnects relay 24, connects up the line wipers 41, 42 at contact-s43, 44, closes contacts 45, 46 so as to maintain earth on test'conductor 16 and connects up the test wiper 40 from which earth is received back before relay 24 falls away. Relay 37 also closes contact 47 to complete a circuit for an auxiliary relay 53. The'ilnpulse sender IS consistsof a forwardly hunting switch having a semi-cylindrical contact bank with four sets of-25 contacts, the sets being ar- I ranged in pairs and adapted to be wiped over by two pairs of wipers diametrically opposite to each other so as to be equivalent to a- 2 wiper 50'step switch.

The marking contacts of the impulse lease relay 63 which on energizing connects earth to test wiper 46 at 64 tohold up the relays 37, 13, and R1 and at the same time closes contact 65.. a

Relay 62 to which a dial'tone may conveniently be connected in known manner is now ready to respond to the impulses generated by the calling subscriber. At the same time impulses are generated by the impulse sender IS in accordance with the number of the calling party. The latter operation will be dealt withfirst although as the two operations in the present example can take place at the same time, this is merely a matter of convenience. In other embodiments of the invention this latter operation may be deferred until one or more series of impulses have been generated by the calling party.

WVhen relay 53 operated as previously described acircuit was closed as follows: earth, interrupter 66, contact 67 contact 68, relay 69 to battery Relay 69 is thereupon intermittently energized. At contact 70 a circuit is closed for magnet 71 0f the impulse sender IS to step the wipers round. On the first interruption of the circuitof magnet 71a circuit is closed on the next contact to normal for relay 72 as follows: earth, second contact engaged by wiper 73, relay 72 to battery. Re-

lay 72 energizes and at contact'73 removes earth from impulsing lead 74 connected over contact 76 to wiper 75 of switch MSS; It

should be mentioned that relay 5 3 at contact 76 had previously completed a circuit from earth on contact 73 over the impulse lead and wiper 75 for relay 77. Relay 77 being slow to release remains energized as long as which due to its continued de-energization permits the release of relay 77. Relay 77 at contact completed a circuit for the lower winding of relay 86 which partially energized sufiicient to close contact 87fand connect the release trunk conductor to its fupper 'wind- V of finder selector FS.

ing, so that on the de-energization of relay 77 and the: consequent opening of contact 85,

thetwo windings of relay 86 were energized in series and relay 86 fully energized to connect atcontact 89 the impulselead over back contact 88 to. vertical magnet ,80 of steer switch SS1 and over wiper 81 to magnet 82 At contact 90 a circuit is prepared for the .partialinitial encrgization of relay 79 which is a similar relay to relay 86., At the impulse sender 1S thevrelay 8 1 on energizing locked itself energized over contacts 91 and 92 and at contact'93 completed a circuit for magnet 71 from wiper 7 3 over contact 93, interrupter contact 99, magnet 71,

to battery. Consequently the magnet rotates .Irapidly unti-l wiper '73 reaches contact 100 from which earth has been removed at contact 101 of relay 53. When this contact is reached relay 72 becomes de-energized and releases shortly after being followed after another short interval by relay 8 1 when the original circuit for relay 69'isagain completed at contact 68. The transmission of impulses then proceeds as before after the relay 7 2 has been energized on the'completion of the first impulse, but this timethe impulses besides controlling relay 77 also cause the magnets80 and V 82 to advance the wipers of the switches SS1 and F S to the s xth level. This is because the wiper 83 completes a circuit for relay 8 1 when ,six impulses have been generated and the same cycle'of operations proceeds as before 7 to advance the wipers to a normal position,

the wipers 73 being now connected to Contact 100. In the meantime relay 77 which was energized throughout the series of impulses had completed a circuit for the lower winding of relay 79' through-contacts 85 and which partially energized to close contact 10 1, to connect the upper winding to the release trunk conductor and fully energized from earth on contact 64, when relay 77 de-ener-.

gized, through both windings in series. Re-

, lay 7 9 at contact completes a circuit for: interrupter 107, conrelay 106' from earth, tacts 108, 105, relay-106 to battery. Relay 106 energizes intermittently and on its first energization at contact 109 completes a pan- 7 tial energizing circuit for relay 110 which closes contact .111; connected to the release trunk conductor 112 which is earthed at-contact 6 1. Relay 110 therefore energizes immediately after the first impulsePis completed and prepares a circuit'for rotary magnet 113 of switch SS1 and over wiper 11 1 for rotary magnet 1150f switch FS so that on the'next impulse the wipers of both switches arestepped on to the first contact of the sixth level. At the same tiinea partial energizing circuit-is prepared for relay 116 over contacts 117 and 118 which relay then closes con-- tact 119 so, that on the cessation of the next impulse, both its windingsare-energized in from earth on lead 112. ,Relay 116 same switch.

a relay 137, which energizes mmediately calling subscribers number.

prepares the. following test circuit, battery, resistance 120,.contact 121, relay 122, earth, contact 121 being also connected over contact 123 to test wiper 124: of switch SS1. If the test wiper is connected to an earthed contact indicating that the first finder selector is busy then relay 122 is shortcircuited and the rotary magnets are energized again to step the wipers to the second contacts, and so on until an idle finder selector is found; when this occurs relay, 122 energizes, closes contact 125 and disconnects contact 123. It also opens contact 108 and contact 126 so that neither the relay 106 nor the magnets 113 and 115 can be again energized. The wipers 127, 128, 129 of the switch FS are connected to contacts directly connected to tlieiwipers 130, 131, 132 of a connector finder switch CFl while the wipers 133, 1341 of the switchSSl are connected to contacts directly connected to the vertical'and rotary magnets 135 and 136 of the The contact 124- is connected to earth is placed on wiper 12 1, through off normal springs 138 and completes a locking circuit for itselfat contact 139 independently thereof; Relay'137 also opens contacts 140 and 141 so to disconnect the release magnet 1 12 and the test wiper 131.

' As it isthe, multiples of the contact engaged by wiper 124 in the banks of the switches SS1 and SS l which guard the connector finderswitch CFl froinintriision and fur ther as when the switch SP1 is used as a connector the wiper 131 must be ,used to test .if the wanted subsci'ibers line is free, whether the contact en a ed thereb t is connected to earth potent al. or not it will be clear tnat relay 137 by disconnecting the twomultiple leadsenables the different function served b y the third conductor to be performed in proper manner.

T1116 rotary movement of the switches SS1 and FS takes place in the prearranged time interval which elapses before relays 72 and 8 1 de-energize to initiate the generatir n of the series of impulses determined by relay R1 and termination of the series of impulses and at contact-146 transfers the impulsing circuit to wiper 13a and rotary magnet 136 so that the next seriescf impulses cause the wipers of the switch CFl to be stepped on to the contacts connected to the calling subscribers line. lVhen the impulse sender IS advances so that wiper 102 engages contact 251 and wiper 103 engages contact 252, relay 72 deenergizes, but relay 84 is maintained energi'zed from contact 253 sothat the further operation of IS is prevented. It will thus be appreciated that irrespective of whether the subscriber dials or not as soon as he lifts his receiver, his line is automatically associated with a trunk relay group overtwo serially related finder switches which differ from the ordinary finder in that they are operated in a similar manner to selector and connector switches and the arrangement of connection over contacts 5459 renders it impossible for one calling line to intercept a finder operated slightly previously by another calling line.

All the usual problems of finder switches are eliminated and the operation is just as positive and certain as the operation of Strowger I group selector and connector switches in use at the present day. The contact 101 is provided to connect earth to all intermediate contacts and leave only the first contact disconnected so as to ensure that if the subscriber hangs up before the finder switches have been operated, the impulse sender IS will restore to normal. The operation of the switches which connect up the wanted subscribers line will now be described. The line relay 62' being energized over the calling subscribers loop as previously described deenergizes in response to the operation of his dial switch. As the first digit to be dialled is seven, the line relay 62 will de-energize seven times, completing a circuit for relay 147 in parallel with verticalmagnets 1 18, 1419, 150 of the switches SS8, SS2 and GS respectively as follows: earth, contacts 243, 251, contact 65, relay 14:7 to battery, and contact 15h, magnets 14:8, 149 to battery, and wiper 158 and vertical magnet 150 to battery.

Relay 147 prepares a circuit to cause the partial energixation of first digit relay 1541 while the switches SS3. SS2 and GS are steppedto the seventh level. On the termination of the seventh impulse, relay 154 fully energizes and at contact 155 closes the following circuits: battery, relay 156, contact 155, contacts 157 and 158 in parallel, interrupter 107 (although three interrupters are shown only one 15 necessary so only one reference is used for the three), earth. Relay 156 therefore energizes intermittently; on its first energization it closes a partial energizing circuit for relay 159, which fully energizes on the completion of the impulse. Relay 159 energizes so that on the next energization of relay 156, a circuit is completed as follows: earth, contacts 160,161, 162, rotary magnet 163 of switch SS3 to battery, also .over contact 164, rotary magnet 165 of switch SS2 to battery, also over wiper 166 to rotary magnet 160 of switch GS to battery. The

v 186 of switch contact 172 and test wiper 173 and earth,

battery, resistance 17 1, contact 175, relay 176 in parallel with contact 177 and test wiper 178. As long as the test wipers are in conneetion withearthed contact-s corresponding to busy lines, the relays 1.7 6 and 171will be short circuited. ,As soon aswipcr 178 reaches an idle line,'relay 176 will energize, opening at contact 164 the impulsing circuit for re tary magnets 165 and 160 so that the switches GS and SS2 come to rest on corresponding sets of contacts on the seventh level. When wiper173 reaches an idle line, relay 171 will energize opening at contact 162 the impulsing circuit for rotary magnet 163 so that the switch SS8 will be arrested. The extent'of the rotary movement ofswitch SS3 is determined independently of the movement of switches GS and SS2. 7

Relay 17 6 by closingcontact 179 connects guarding potential to wiper 178 and at the sametime opens contact 177' to prevent it I On the calling subscriber operating his dial switch for the second digit to send out six impulses, the line relay 62 responds and the impulses'may then be traced over the follow? ing circuits, relay 154: being now fully enorgized earth, contacts 21-3, 151, 65 to relay 147 which energizes and closesv a partial energizing circuit for relay 181, also the impula ing circuit extends over contacts 182, 183,

wiper 184: of switch SS2, vertical magnet 185 of switch CFS to battery, so that thewipers of this switch are stepped to the sixth level. The impulsing circuit also extends over wiper S3, relay 187 to battery, while a branch extends over contact 188, vertical magnet 189 of switch SS4 to battery, so that the wipers of switch SS4 are also stepped to the sixth level. Now the connectors connected to the sixth level of SS4; are arranged to be the same connectors arranged in the same order as are connected to switch CFS, so that the number of steps taken by the wipers of to the number offsteps to be taken by the wipers of CFS to reach the same connector. I

Relay, '187c1oses a partial energizing circuit for relay 190, which fully energizing when relay 187 falls away and closes the following circuit: earth, interrupter 194, contacts 191, 192, relay 193 to battery, Relay "193 ener 'izes intermittentl and on its first energization closes a partial energizing circuit for relay 195 which fully energizes on the subsequent deenergization and closes contact 196 so that on the nextenergization'of relay 193 a circuit is completed as follows: earth, contacts 197,196, 198, rotarymagnet 199 to battery, While a branch of this circuit extends over wiper 200, wiper 201, rotary magnet 202 of switch CF S to battery. The two magnets step together until SS4 finds an idle connector finder such as CF2. The test circuit is prepared byrelay 203 which energizes after the second impulse when the wipers of switches SS4 and CFS are resting on the first contactsin the level. This test cir cuit is similar to those previously described and'consists of earth, battery, resistance 294, contact 205, relay 206. to earth, with a branch circuitextending over contact 207 to wiper .208. Relay 206 is therefore short circuited until an idle line is reached when it energizes, opens contacts 198 and 191 to disconnectthe magnets and interrupter so that the wipers are brought to rest on corresponding nation of the second series of impulses, con- I level,

tact 183 is opened and the next two series of Dealing with the be ti'aced'as follows: earth, contacts 243, 151,

65, 182, iwiper 186, contacts 210, 211, wipe 212, vertical magnet 213, to, battery; the

switch CF2 is thereupon stepped to the second On the terminationof this series of impulses relay 210 fully energizes and transfers the previously described impulsing cir-- cuit to wiper 214 and rotary magnet 215 to battery, so that the units digit then steps the wipers of the switch C1 2 on to .thecontacts the wanted subscribeflsline' At, this time the switch CF 1 will also have been set on, to the calling subscribers line.

Now referring to F 5, it will have been noted that the relay 154 fully energized after theiirst series of impulses andrelay 181 after fourth. ,Relay 217 closes contact 218 to test 1 the wanted subscribers line. If the wanted line is busy the following circuit is completed battery, resistance 219, con'tact218, wiper 220, contact 232, relay E, contacts 221, 222, wiper 223, wiper 224, wiper 225, which is earthed under these conditions, It should bementioned here 51121111116 connection of guarding potential to wiper 178 causes the energization of relay 226, over 011 normal contact 227 which relay at contacts 228 and 229 disconnected wiper 224 and release magnet 230 and prepared a locking circuit for itself at 231 independent of of? normal contact 227. Similarly the connect-ion of guarding potential to wiper 208 caused the energiza t-ion of relay 232 over 011 normal contact 233, which relay at contacts 234 and 235 disconnected wiper 225 and release magnet 236.

This arrangement therefore ensures that the testing is direct and is not affected by any connections to the test leads of the intermediate switches, while'at the same time the protection is guarded as all means of access are connected to earth potential. Re-

lay E on energizing disconnects contact 220 at 232 and at 233 connects up battery through resistance 234 direct, atv the same time it opens contact 221 and establishes a locking circuit for itself over contact 235, wiper 236, contact 237, earth (relay 238 being energized at the time the m'ainsteerer MS is selected as will I be described later). At contact 239 busy tone is connected to wiper 129and at contacts 240, 241, 242', the wipers 127, 128 and 129 are connected up. These operations are not effective in bringing about any definite result until another operation has taken place which will now be described. Vihen relay 217 energized at the end of the last series of impulses contacts 243 and 244 were opened. The opening-of contact 24.4 is without effect at this time as relay 238 is maintained energized independently thereof from earth on contact 64.

The opening of contact 243 opens the circuit of release relay :63 so that contact 64 opens shortly after, while a circuit is prepared for the release magnets 245, 246, 247 at contact 248. The opening of contact 64 releases the relays 37, 250 and R1 (Fig. 2). Relay 37 opensthe circuit of relay 53, which deenergizes and opens contact 253' and closes contact101 and'contact 400-; inagnet'71 is there upon energized and the wipers of IS arcadv'anccd one step tonormal. Relays 72' and 84 thereupon de-energize as they are now longer held up over contacts 251 and 252 respectively. Relay 250 de-energiz'es and connects earth to contact 49 so as to complete a point in the circuit of the line relays of the subscribers group to which 1S belongs. Re-

lay 111 (lo-energizes but not relay 13 which is maintained energized over the following circuit: earth, contact 237, wiper 236, contact 241, wipers 128, 131, relay 13, resistance 20 to battery. Relay R1 at contacts 254, 255,

relay A to earth. Relay A energizes and completes a circuit for relay B at contact 256,

which relay energizesand at contact 257 connects earth to wiper 236 in place of the earth connection at contact 237 which is removed when relay 238 falls away a short while after contact 61 is opened. The opening of contact 61 causes the relays 151, 181, 216, 159, 168, 86, 79, 115, 116, 110 to de-energize. Relay 168 opens the circuits of relays 176 and 171 which also de-energize while relay 116 opens the circuitof relay 122 which de-energizes. The opening of contact 61 removes earth connection from wipers 124, 178, 173, thereby causing relays 137, 226 and 190, 210, 195, 203 and 232 to de-energize so that wiper 131 is connected to wiper 121 over contact 111, wiper 221 is connected to contact 178 over contact 228, and wiper 225 is connected to wiper 208 over contact 231. An extra relay 258 which is maintained energized by the closure of contact 61 is provided for opening the circuit of release magnet 259 of the switch SS1 so that it is also released at this time and completes a circuit as follows earth, contact 260, 011 normal springs 261, release magnet 259 to battery. The release magnet ener izes and restores switch SS1 to normal.

7 mal. Relay 217 also closes contact 241 so that a circuit is prepared for relay 238. The magnet 265 stepsjthe wipers 11a, 81, 236, 163, 166 of switch TF until wiper 236 finds an unearthed contact, then relay 238 energizes in series with the rotary magnet 265 to connect earth to wiper 236 at contact 237 to prevent the idle trunk line found being seized by any other trunk iindeim The main steerer and its associated switches are now restored to normal and as an idle trunk line has been preselected. everything is in readiness for the next call. T he release of the main steerer and the removal of earth connection from the wipers 12-1, 178, 208 causes the relays 137, 226, 232 to release thereby completing the following circuits: battery, resistance 276, contact 140, off normal springs 277, release magnet 142 to earth, battery, resistance 278, contact 228, off normal springs 279, release magnet 230 to earth, and battery, resistance 280, contact 235, off normal springs 281, re lease magnet 236 to earth. Release magnet 141-2 cannot energize in this circuit as t is short circuitedduc to the connections over.

1 11 with test wiper 223, which is earthed at contact 257. Release magnets 2'30 and 236 do however energize as the only earth connections to the contacts 228 and 231 are either over resistance 282 to wiper 225 or over the upper winding of relay Rand there is consequently no direct, short circuit and thecirenergize, so that switch CF 1 restores to normal, also relay 13 (lo-energizes and the subscribers line circuit is restored to normal. The closing of contact 283 when relay B deenergizes, completes an energizing circuit for release magnets 281 and 285 as follows: battery, resistance 2'86, contact 283, 011 normal springs 287, release magnet 28 1, and off nor-. mal springs 288, release magnet 285 to earth.

It will be noted that this circuit was coin 'pleted before relay B energized after the switches FS and GS had stepped 011, normal but was ineffective owing to theeartli connection over wiper 236. Relay D also releases so that everything is now restored to norn'ial. So far consideration has only been given to the case of the wanted subscriber being busy, if however when his line was tested he was idle, no circuit would be completed for relay E. been energized as follows in series with the cut 011 relay (corresponding to relay 13) of the wanted line, (for the sake of convenience the parts of the wanted subscribers line will" be given the same reference letters as the -cor-. responding parts of the calling subscribers line) earth on wiper 236, upper winding of relay F, contact 222, wipers 223, 224;, resistance 282, wiper 2'25, relay 13, resistance 20 to battery. Relay 13 and relay F energize in series; relay 13 opens contacts 51 and 52 to cut off relay 10 and also opens contacts 21 and 18 and connects up wipers 289, 290, over contacts 22 and 251 and 23 and 255 respectively.

Relay E would however have Relay F closes contact 291 connecting direct contacts 293, 300, upper winding of relay D to battery. As the operation of the release of the steerer switches is dependent upon the lapse of a short time'interval after the trans-' mission of the last digit and is not dependent 7 scribers line tests busy or not, therelease subscribers over relays A and'C.

of the steerer switches will proceed exactly in the same way as previously described. The only dill erences concern the switches used for the established connection. It will be noted .that relay E closes contacts 301, 802,303 in parallel with contacts 2&0, 241, 242, so that the same function is performed as regards connecting up relay A and the test conductor whichever relay is operated. Consequently the operation by which connection is established to the calling" line is identical with that previously described. The switches CFS and CFQ do not-restore to normal as the release magnets 230, 23.6 are short circuited by, direct earth on'contaets 228,- 234,. which may be traced from contact 257 or wiper 236. lVhen the wanted subscriber answers, the ringin trip relay D energizes, locks itself energized at 30% and at 305 and 306 completes a cireuitfor the back bridge relay C over the previously traced circuit, including the wanted subscrlbers loop. Gonversation can now' proceed, battery bemg ted to the. two

conversation is finished, the release takes place as previously described in the case when the calling subscriber was busy, except in this case the opening of contact 257 removes the, short circuit ot' the release magnets of switches GFS, CFQ, which release and restore to normal. It will be noted that whatever should happen. the release of the connections becomes ultimately dependent on relay A or relay 62,- so that it the calling subscriber should hang up prematurely, everything will be restored to normal.

' Having now particularly described and ascertained the nature of my invention and in what manner the same is to be performed, I declare that what Iclaim is:

1-. In a telephone system, a switchhaving wipers adapted to be moved. a variable distance to make contact with one set of 'a plurality of sets or contacts, a similar switch to a set of contacts of which the first switch is connected, an auxiliary switch and means for operating it in synchronism with said second switch, and controlling magnets for said first switch connected directly to contacts of said auxiliary switch independently of the wipers of said first switch.

2. In a telephone system, a directively controlled switch, a second directively controlled switch in serial J relation therewith, and a third switch similar in capacity to and vassociated with said first switch to obtain di rect access to the motor magnets of said second switch independently'ot the wipers of said first switch.

- In a: telephone system a switch having wipers adapted to be moved a variable dis tance to make contact with one set of a plurality of sets of contacts, a secondswitch lVhen the e to a set of contacts of which the first switch is connected,an auxiliary switch similar'in capacity to and operated in parallel with said second switch to obtain direct access to themotor magnetsot said first switch independently of the wipers of said first switch. 4. In a telephone system, a group selector, :1 second group selector in serial relation therewith, a switch, means for temporarily associating said switch with said first group selector, means 'for setting said switch and said first group selector simultaneously, and a circuit extending over the wipers of said switch tor controlling the operation of said second roup selector independent of the wipers OI said first group selector.

' 5. In a telephone system, a finder switch, a second finder switch accessible to the wipers of said first finder, a third switch, means for temporarily associating said third switcli with said first finder switch, and circuits extending over the wipers of said third switch 111g over the wipers of said switch for controlling the operation of said final selector independent of the wipers of said group selector.

7. In a telephone system, a group selector, a second group selector accessible to the wipers of said first group selector, a directively controlled switch, means for temporarily associating said switch with said first group selector, and a circuit extending over the wipers or said switch for controlling the operation'ot said second group select-or independent ot the wipers'ot said first group selector. 7 8; In a telephone system a finder switch, a second finder switch in serial relation therewith, a thirdswitch directively controlled, means for temporarily associating said third switch with said first finder-switch, and circuits extending over the wipers of said third switch for controlling the operation of said second finder.

9. In a telephone system, a group selector, a final selector in serial relation therewith, adirectively controlled switch similar in capacity to said group selector, means for temporarily associating said switch with said group selector, and a circuit extending over the wipers of said switch for controlling the operation of said final selector independent of the wipers of said group selector.

10. In a telephone systenna switch, an operating magnet for switch, an auxiliary I switching device,.directively controlled means 11. In a telephone system, a selector switch,

an auxiliary switch, means for effecting the operation or the two switches in unison, a talking circuit adapted to be extended over the wipers of said sel ctor switch to a third switch and an operating circuit to be extended over the wipers of said auxiliary switch to the control magnets of said third switch.

12. A telephone system comprising a set of switches in use throughout a connection, a second set of switches inuse only during the setting up of a connection, means for tem porarily associating said second set of switcheswith said first set o1 switches and means for controlling corresponding switches in each set to operate together to establish connection with the same switch in the first set.

13. A telephone system comprising a set of switches including a number of ranks of switches in serial relationship, a second set of switches also including a number of ranks of switches in'serial relationship but one less than the preceding number of ranks, means for temporarily associating said second set of switches with said first set of switches only during the setting up or" a connection, and means for operating switches in corresponding ranks of each set simultaneously.

14. In a telephone system, a train of switches in serial relationship, a train of auxiliary switches in serial relationship one less in number than the number of said first switches, means for temporarily associating each of said auxiliary switches with a corresponding one of said first mentioned switches, and a circuit extending over all said auxiliary switches in serial relationship to control the operation of the magnets of tholast switch ins-aid first mentioned train of switches.

15. In a telephone system, a switch over I the wipers of which a talking circuit is adapted to be set up, an auxiliary switch, means for temporarily associating said auxiliary switch with said first mentioned switch and means for controlling said auxiliary switch to cause its wipers to take up a position corresponding to the position taken up by the wipers of the main switch.

16. In a telephone system, two switches in serial relationship, a plurality of operating magnets for each of said switches, means including a directively controlled switch for completing operating circuits for the magnets ofsaid first switch successively, means including a second directively controlled switch for completing operating circuits for the magnets of said second switch successively and an auxiliary switching apparatus embodied in a single unit adapted to associate both said meanswith said magnets only 7 during the setting up of a connection.

17. In a telephone system a plurality of switches in serial relationship, operating magnets for each of said switches, a steering device for completing operating circuits for all said magnets successively, and means for associating said steering device with the magnets of said switches independently of any of the wipers of said switches.

18. In a telephone system, a first group selector, a second group selector and a final selector all in serial relationship, switch controlling means for said selectors. associated with said first group selector, said means being normally arranged to effect both directive and hunting movementcontrol as to any selector being controlled, progressively operated means also associated with the first group selector to respond on the operation of the first and second group selector succes-- magnets for said switches, a main steering device for completing operating circuits for some of SttlCl magnets, successively, a'subsidiary steerlng devlce accessible to said main steerer independent of said switches for sub- 7 sequently completing operating circuits for other oi said magnets successively and means for associating said steering devices with.

each other and with said switches temporarily during the setting up of a connection.

20. In a telephone system, a plurality of switches in serial relationship, primary and secondary operating magnets for each of said switches, a steering device for completing operating circuits for the operating magnets of each of said switchessuccessively, and

means for associating said steering device with the magnets of said switches temporz rily during the setting up of a connection. 7

21. In a telephone system, a plurality of switches in serial relationship, operating magnets for said switches, a main steering device, a subsidiary steering device, a control magnets for said switches, a main steeing' device for completing operating circuits for some of said magnets successively, a subsidi ary steering device for completing operating circuits for other of said magnets successively I dependent of said switches.

23. A- telephone system comprising a switch, a second switch, a third switch, controlling means for causing said first switch and said second switch to operate simultaneously to establish connection with said third switch, an intermediate switch for connecting the controlling means to said first switch and asecond intermediate switch for connecting the controlling means tosaid second switch.

24;. In a telephone'system, a switch, means of access to saidjswitch from the bank contacts of a preceding switch including talking leads permanently connected to the wipers of said first'switch, a second means of access to said first switch including switch controlling leads, and operating magnets for said first switch connected directly ,to the switch controlling leads. I I I Y 25. In a telephone system a group selector having movement in two stages, a magnet directively operated to control the selector for one stage of its movement, a magnet operated until an idle linewis reached by the wipers of the selector to controlfthe selector for the other stage of its movement,"a means of access to said switch including thetalking leads permanently connected tothe wipers of said switch, and asecond means of access to which both magnets are directly connected.

26. In a telephone system, a switch, an operating magnet for said switch, an auxiliary switching device, directively controlled means foroperating said device to connect up a control circuit. to the operating magnet of said switch and means associated with said control circuit for causing said operating magnet to move the wipers of said switch to line of agroup. I

27, In a telephone system, a switch, an operating magnet for said switch, a second op-' eratingniagnet for said switch, an auxiliary switching device, directively controlled means for operating said deviceto connect up'control circuits to the operating magnets of said vice.

switch, directively controlled means for operating said first magnet over one of said control circuits, means associated with one of said control circuits for causing said second operating magnet to move the wipers of the switch on to an idle line of a group.

28. In a telephone system, three switches in serial relationship, two auxiliary switching devices similar in capacity tothe; first and second switches, respectively, control circuits extending from said auxiliary switches to the operating magnets of said second and third switches, respectively, and means operated due to the operation of the first switch for selecting the second auxiliary switching dean idle 29. In a telephone system, a step by step 7 switch, a second step by step 'switchto a set of contacts of which the first switch is connected,

an auxiliary selecting device operated step by step in unison with said second switch and controlling motor magnets for said first wipers of said third switch for controllingthe operation of said second finder.

31. In a telephone system, a group selector, a final selector, a lead extending to said group selector over which the directive control of the group selector is effected, a second lead eX- tending to said group selector over which the automatic control of the group selector to find an idle line'is effected, two leads extending to said final selector overwhich dilferent directive controls of said final selector are effected, controlling means-through the -in-. t'ermediary of which both the group selector and final selector are operated, and steering means separate from said final selector by which all said leads are successively connected up to said controlling means.

32. In a telephone system, a group selector, a final selector, a lead extending to said group selectorover which the directive control of the group selector is effected, a second lead extending to said group selector over which the automatic control of the group selector to find an idle line is efiiected, two leads extending to said final selector over which diilerent directive controls'of saidfinal selector are matically controlled impulses are transmitted, two leads extending to said final selector over which different series of directively controlled impulses'are transmitted and a steering means separate from said final selector by which all said leads are successively connected to impulsing devices. r

34. In a telephone system, a group selector, a final selector, a lead extending to said group selector over which directively controlled impulses are transmitted, a second lead extending to said group selector over which automatically controlled impulses are transmitted, a lead extending to said final selector over which one series of directively controlled impulses is transi'nitted, a second lead extending to said final selector over which a different series directivcly controlled impulses is transmitted, impulsing devices through the intermediary, of which both the group selector and final selector are operated, and a steering means to which all said leads are connected and by which all said leads are successively connected to said impulsing devices.

35. In a telephone system, a group selector, a final selector, a vertical magnet and a 1'0 .tary magnet for each of said selectors, impuls ing devices, separate leads extending from said impulsing devices to said magnets, steering means by which saidleads are successively connected to the impulsing devices, and means for associating said steering means with said selectors only during the setting up of a connection.

36. Ina telephone system, a group selector, a final selector, a lead extending to said group selector over which the directive control ot the group selector is e'l'l'ected, a second lead extending to said group selector over which the automatic control 'ofthe group selector to find an idle line is effected, two leads extending to said final selector over which different directive controls of said final selector are effected, controlling means through the intermediary of which both the group selector and final selector are operated, and steering means associated with said group selector by which all said leads are successively connected up to said controlling means. I

37. In a telephone system, a plurality of switches in serial relationshil operating magnets for said switches, a main steering device I for completing operating circuits for some of said magnets, successively, a subsidiary steering device for completing operating circuits :lor other or" said magnets, successively,means for selecting an idle line in a group associated with said main steerer, means for selecting an idle subsidiary steerer from said main steerer. and controlling means whereby the group selections and subsidiary steerer selection take place simultaneously.

38. in a telephone system, a plurality of switches in serial relationship, operating magnetslor said switches, a main steering device for completing operating circuits for some of said magnets successively, a subsidiary steering device for completing circuits for other of said magnets, successively, said steerer comprising means for responding to and roiiiting the various series of impulses received by said steerer, means for selecting an idle subsidiary steerer associated with said main stcorcrfand means operated on the re ception the first series for initiating the operation of said selecting means.

39. In a telephone system, a switch, a second switch having a movement in a plurality of stages connected to the bank contacts of the preceding switch, a switching device constituting the sole device permanently associated with the second switch which is oper ated after the switch has made an initial movement and a steering device associated with said first switch for preparing for the ditl'erent stages of operation of said second switch. i i

40.- In a telephone system, a relay respon-.

sive to individual impulses, a step by step switch having nonnpulse respondin relay permanently associated therewith, a second switch having wipers over which said relay s connected with said first switch only during the setting up ot a connection, and means for directively controlling said second switch to seize said first switch.

41. In a telephone system, a relay of the slow to release type, a step by step switch having no relays of the slow to release type associated therewith, and a hunting switch adapted to connect up said relay to "control the release of said first switch only during the s tting up 01 a connection: i

42. In a telephone system, a relay adapted to prepare a treshoperating circuit after e eh series of impulses, afirst and a second .1

step by step switch each having two operating magnets, but no such relay associated thercwith, and means tor temporarily associating said relay with said switches to enable said magnets to be successively rendered operable.

413. In a telephone system, a relay responsive to individual impulses, a relay oi the slow to release type, a relay responsive to individual trains of impulses, a step by step switch having no such relays associat 1d therewith, two operating magnets for said switch, and a hunting switch by which said relays may be associated with said switch to etl'ect the operation of the swi I lines, a switch for directly connecting with any one of said subscribers lines, a test lead for said switch, guard lead'ior said switch,

means for normally connecting said test lead and guard lead together and means operated due to the switch being taken into use to separate said leads so that they can each beused for their separate functions.

46. In a telephone system, a switch, two impulsing circuits extending-over the wipers'ot I said Switch, directively controlled means for transmitting impulses over one of said circuits in accordance with a digit in thenumber allotted to a subscriber and an automatically controlled lmpulsegenerator ior trans mittmg lmpulses to said switch over the other of said circuits in accordance with the idle condition of a line in a roup of lines.v

47. In a telephone system, a switch, two impulsing circuitsextending over the wipers of said switch, directively' controlled means for transmitting impulses over one of said circuits in accordance with a plurality of digits inthe directory number allotted to a called subscriber, and automatically, controll d means "for transmittingimpulses over the other of. said circuitsin accordance with the idle condition of a line in a group .oflinesr preparing for the operation'oi" the control magnets of the second numerical switch,

means operated when the first 'n'u-merical switch is taken. into use for connecting said first preparing means to said first numerical switch by said first auxiliary switch, and means operated when the second numerical switch is taken into use for connecting said second preparing means to said second numerical switch by said directively controlled switch. V

49. In a 'tele hone s stem a switch an i operating magnet for said switch, a second operating magnet for said switch, a lead incomlng to said switch for testing purposes,

' a second lead ,in comingto-said switch for guardlng purposes, a third "lncolnllig lead over which impulses are transmitted to operate said first operating magnet, and a fourth incoming lead over which impulses are trans :llllttetl too'perate' said second operating magnet .to operate said switch to line in a group of lines. e V H 5(). In a telephone system,-a two stage nuselect an idle meric'alswitch, a second two stage numerical 7 switch in serial relation therewith, means for preparing for the operation of the magnets controlling the two stages of movement of the first switch, means for preparing for the operation of the magnets controlling the'two stages ofmovement of the second switch, means for associating said first preparing meanswith said first switch as thefirst switch vis taken into use and directly controlled means for associating said second preparing -means withsaidpsecond switch as the second switch 51-. In a'telephone system, atwo stage nuniericalswitch, a secondtwo stage numerical switch inser al I'GltLlZlOll therew1th,fmeans for preparing for theoperation of the magnets controlling the two stages of movement of the firstswitch, means for preparing for the operation of the magnets controlling the two stages of movement of the second switch, a directlvely controlled switch for associating said first preparing means with said first switch as the first switch is taken into use only during the setting up of a connection, and-means for associating said second prepar ing means with said second switch as the second switchis taken into use only during the setting up of a connection.

52., In a telephone system, a two directional step by step'switch, a second two directional step by step switch in serial relation therewith, two impulsing circuits for the magnets of the first step by step switch, two impulsing circuits forthe magnets of the second step by step switch, a switch, for associating said first two impulsing circuits with the magnets of the first step by step switch when the first step by step switch is taken into use and only during the setting up of a connection, and

a directively controlled switch for associating said second-two impulsing circuits with the magnetsvof the second step by step switch when the second step by step switch is taken into useand only during the setting up ofa connection. 7 v

53. In a telephonesystem, a switch, two sets of incoming-leads forsaidswit'ch each set comprising onlythree leads, a test lead included in one of said sets of leads, and a guard lead included in the other set oileads.

54:. In a telephonesystem, a switch, three leads incoming to said switch, controlling means for said switch controlled over all said leads to cause it to set its wipers on a calling line, controlling means for said switch controlled over exactly the sameleads to cause it to set its wipers on a called line, means for associating the first controlling means with said switch whena line to which it has access is calling and means for associating the second controlling means with said switchwhen a line to which the switch has access is called.

55. Ina telephonesystem, a switch, three incoming leadsfor said switch, controlling means for said switch controlled over allsaid cordance with the. controlling means associated with it.

' 56. Inatele'phone system, a switch, controlling means for said switch to cause it to set'its'wiperson a calling line, controlling means for said switch to causeit to set its wipers on a called line, said last mentioned means comprising an impulse sender for transmitting directive impulses to the magnets of said switch, and means for temporarily associating only during the setting up of a connection the first controlling means with said switch when a line to which it has access is calling'and means for temporarily associating only during the setting up of a connection the second controlling means with said switch when a line to which the switch has access is called.

57. In a telephone system, a selector switch for connectingwith idle trunk lines, a connector switch accessible to said selector over one of said trunk lines, controllingapparatus for said selector switch separate therefrom and ci'introlling apparatus for said connector switch separate therefrom, said controlling apparatus being so designed that the operation of both the selector and connector switches is identical.

58. In a telephone system, a connector switch'of the step by step type, afinder switch of the step by step type, apparatus for transmitting impulses to the magnet 0r magnets of said connector switch, but separate therefrom, apparatus for transmitting impulses to the magnet or magnets of said 'finder switch but separate therefrom, and means for releasing said apparatusfrom said switches as soon as the setting up of a connection is completed so that during the ensuing conversation said apparatus can be used to set up other con- 'nections.

I 59. In a telephone system, a switch, one means of access to said switch, a second means of access to said switch, controlling arrangements for said switch comprising a subscribers dial associated with one means of access, other controlling arrangements comprising a register sender at the exchange, associated with the othermeans of access, the whole of the apparatus permanently associated with the switch being operated in an identical manner whichever means of accessis used.

switch for establishing connection with a calling line, a step by step switch for establishing connection with a called line, a distribut ing apparatus by which impulses are transmitted to saidswitches simultaneously and separate and independent circuits extending from said distributing apparatus to said switches.

-62. In a telephone system, a twodirectional switch for establishing connection with 'acalling line, a two d rectional switch for establishing connection with a called line, a.

distributing apparatus by which impulses ar transmitted to said switches and four separate and independent circuits extending from said distributing apparatus, two to the magnets of the first switch and two to the magnets of the second switch.

63. In a telephone system, a two directional switch 'l'or establishing connection with a calling line, a plurality oftwo directional V switches inserial relationship for establish- I ing connection with a called line, a distributing apparatus by which impulses are transmitted to said switches and separate and in dependent pairs of impulsmg c rcuits extend ing from said distributing apparatus to each line, a plurality of two directionalswitches in serial relationship for establishing connection with a called line, a distributing apparatus by which impulsesare transmitted to said switches and separate and independent pairs of impulsing circuits extending from said distributing apparatus to each pair of n'iagnets controlling said switches. I

(55. In a telephone system, an impulse sender adapted to generate se 'ies of impulses corresponding to a calling subscribers numher, an impulse responder for responding to series of impulses corresponding to the number of the called line which are generated by the calling subscriber, a switching device for associating said impulse responder with the calling subscribcrs line and means for; automatically associating the impulse sender with said impulse responder responsive to the oper-F ation of said switching device.

66. In a telephone system, an impulse sender adapted. to transmit series of impulses corresponding to a calling subscribers number, an impulse responder for responding to impulses generated by the calling subscriber, and means tor automatical lyassociating said impulse sender and said impulse responder 7 simultaneously with a calling subscribers line. v V

67 In a telephone system, a plurality of direc'tively operated switches in serial relationship for establishing connection with a calling subscribers line, an impulse sender,

a hunting switch adapted to associatesaid' impulse sender with the last switches of the,

series, and a lead or leads connected direct to the control magnet or magnets ofthe last switch of the series from the hunting switch whereby the impulse sender can transmit.

series of impulses directly to said magnet or magnets to set the wipers on contacts to:

which the calling subscribers "line is connected. r

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