US1729856A

US1729856A - tench

Info

Publication number: US1729856A
Authority: US
Priority date: 1926-05-07
Publication date: 1929-10-01
Anticipated expiration: 1946-10-01
Also published as: GB275343A; GB285279A

Description

0a. 1, 1929. F. mac 1,729,856

TELEPHONE sYsml Filed Feb. 26. 1927' 2 Sheets-Sheet 1.

Ir'rmm Frank Tench Oct. 1, 1929. F, TENCH 1,729,856 TELEPHONE SYSTEH Filed Feb. 26, 1927 2 Sheets-Sheet 2 Patented Get. 1, 192.9

TEITCH, OF 11161113031, EEIGLAND, ASSIGNOR T0 ASSOCIATED TELEPHONE- AND TELEGRAPH. GOM?ANY, OF KANSAS CITY, DEISSOURI, A. COEPGRATION OF DELAWARE TELEPHONE SYSTEI'II Application filed February 26, 1927, Serial No. 171,165, and in Great Britain May '7, 1926.

The present invention relates to telephone or like systems and is more particularly concerned with telephone systems in which connections are set up by the subscribers themselves by the transmission of series of impulses which operate automatic switches or the like. The invention moreover specially relates to systems of the type in which some at least of the impulses transmitted by the calling party are stored on registering apparatus at the exchange, from which further trains of impulses are sent out subsequently to effect the setting up of the connection, which trains of impulses will in general differ from those dialled either in number or value or both.

In systems of this type it has been general practice for the whole of the number transmitted by the calling party to be stored at the exchange and this consequently involves the provision of sufficient apparatus thereat to register the complete number. The numer usually divided into two parts, one corresponding to the exchange name, and the other corresponding to the subscribefis numher in the particular exchange, and with the usual layout of a multi-exchange telephone area considerable advantages may be obtained by translating the exchange name while the translation of the numerical digits is of no particular value and is not usually done. Consequently if only the exchange name need be stored and translated, while the numerical digits are neither stored nor translated, a considerable saving is possible in the amount of exchange apparatus required, and thus the first cost of the installation is reduced.

According to one feature of the invention in an automatic telephone system, series of impulses comprising certain digits of a number dialled by a calling party are adapted to be registered and the corresponding impulses retransmitted by a register controller temporarily associated with the connection, while the series of impulses representing the re mainder of the digits of the nber subsa to be temporarily associated with the c0nnecquently serve to operate switches in the speaking route direct.

According to another feature of the invention, a register controller is provided adapted tion and including a register switch comprising a single-motion switch adapted to have its wipers advanced over their banks in re sponse to each of a plurality of series of impulses, the wipers remaining in the position to 5 which they are set by one series of impulses until advanced by the succeeding series.

A further feature of the invention is the provision of a register controller including a register switch adapted to respond to a plurality of series of impulses in which the register switch wipers are adapted to be advanced a number of steps for each impulse of one series transmitted to it and a different numher of steps for each impulse of a series subsequently transmitted to it.

Still another feature of the invention is the provision of an impulse sender employing a rotating counting switch controlling the number of impulses in a trainin which the switch is always advanced the same number of steps between the transmission of two successive trains of impulses.

According to a still further feature of the invention in an impulse sender employing a rotating counting switch adapted to terminate a series of impulses on finding a special potential the special potential. remains connected to a plurality of contacts in the switch 80 bank throughout the sending operation.

lhese features and others not specifically mentioned at this point will be better understood from the following description, which should be taken in conjunction with the accompanying drawings, of one method of carrying the invention into effect. It will be understood, however, that this description is given by way of example only and that variiuiodifications and other the invention will readily occur to those skilled in the art.

The system now to be described is assumed to be a comparatively small one comprising only 30 exchanges so that with suitable choice of exchange names two digits are suflicient to identify an exchange. Di'lliculty has been experienced hitherto in providing the advantages of a register translator system for a network of this size owing to the heavy outlay necessary to equip all the exchanges with register translators adapted to record the complete number dialled by the subscriber. It is proposed to overcome this difficulty according to the present invention by arranging that since only the exchange name is translated, only the exchange name need be recorded on the register translator apparatus. This means that after the subscriber has dialled the first two letters of the exchange name, he must make a short pause whilethe register translator transmits these, translated as necessary, before he dials the appropriatc numerical digits. In order to give him proper Warning, it is proposed to give him suitable tone signals or alternatively to lock his dial until the switches are ready for him to continue dialling. In order to reduce still further the apparatus required at the exchange, it is provided that the switch which responds to the exchange digits comprises a single level switch so that both digits produce a similar kind of motion. For this arrangement to be satisfactory, some considerable care is necessary in the choiceof the exchange names, and in any event the danger of conflict arising is fairly high. In order to reduce this to some extent, it is proposed that in response to the first digit the recording switch shall take a plurality of steps for each impulse, for instance two, whereas in response to the second digit it shall move only one step for each impulse. By this arrangement, the number of different positions to which the switch can be set is increased by approximately and thus the choice of exchange names is not so limited. In order to reduce the danger of conflict still further, it is also conveniently provided that the recording switch has two separate sets of wipers, since by this means two exchange names may be employed which would bring the switch to rest in the same position, one set of wipers then being employed in one case and the other set in the other case.

In the system illustrated in the drawings, it is ssumed that "the numerical equivalents of the first two letters of the 30 exchange names are as set out in the first column of the following table, while the total number of steps which the recording switch then has to take is set out in the second column. It will be seen from these figures that in a number of cases conflict occurs and accordingly it is provided that for first digits of

value

2, 3, 4, 6, 8 and 10, a switching-over occurs so that the second set of wipers is made use of. The exchange names to which this applies are indicated by crosses in the third column. The fourth column sets out the number of digits'in the translated exchange code as determined by the wiring of the bank of wiper 72 of the switch CS.

14 6 3 17 9 1 19 11 3 22 e X 3 24 8 X 3 31 7 X 2 35 11 X 3 36 12 X 2 40 18 X 1 42 '10 X 3 46 14 X 2 47. 15 X 3 48 16 X 1 52 12 2 53 13 3 55 15 3 5s 1s 1 22 X 3 61 13 X s 65 17 X 1 69 21 X 2 70 24 I 3 72 16 1 77 21 2 83 19 X 3 87 23 x 3 94 22 3 95 23 3 97 25 3 04 24 X 3 The operation of the system shown may now be briefiy taken up. Vhen the subscriber removes his receiver, busy tone is connected to his line until a free register translator has been associated therewith, though this will normally take place so quickly that the busy tone will be cut 01f before he has placed the receiver to his ear and dial tone is then substituted. The only function of the busy tone is to warn him not to start dialling in case for any reason it should be impossible for him to obtain a free register translator at once. He will then dial the first two digits of the wanted number whereupon the dial tone will be out off and he will hear nothing while the register translator is send 111g out the translated exchange code for ob- 'taining access to the wanted exchange, though may therefore proceed to dial the remainder of the number. When he does this, he oper ates the requisite switches directly and the connection is completed in the usual manner. In some cases for the sake of keeping the procedure uniform with that of existing systems, it may be considered desirable that the subscriber should dial the first three letters of the exchange name instead of the first two only and in this case the third one is ineliective but may be useful in occupying the subscribers time in the short interval while he is waitin for the signal to dial the numerical digits. As an alternative to the arrangement of tones in the s stem shown and described, it might be possible to arrange for the subscribers dial to be locked while the exchange code is being sent out, for instance, owing to the cessation of current flow over the subscribcrs loop, and only unlocked to enable him to continue dialling when the connection has been cut through to the wanted exchange.

A rather more detailed description will now be given of the system illustrated in the drawings, of which Fig. 1 shows a trunk circuit adapted to be seized from a subscribers individual line switch and to control the association of a free register translator with the connection, while Fig. 2 shows the circuit 01"- the register translator. llt will be assumed in the first instance that the calling subscriber requires to speak to a subscriber whose numher is Mossley 2345. He will accordingly remove his receiver and his line switch will then hunt to find a tree trunk relay group. Assume that the trunk relay group taken into use is that shown in Fig. 1, when the line switch switches through, a circuit is completed over contacts 1 and 9., the line conductors and the subscribe1"s loop for line relay A which accordingly operates, thereupon at armature 5 completing a circuit for relay B and at zn'mature e preparing a locking circuit for relay D. Relay B now operates in its turn and at armature 7 connects earth to release trunk conductor l, this earth extending back over contact 3 to maintain the line switch operated. Relay B also at armature 8 prepares the iinpulsing circuit and at armature 11 connects up busy tone from the lead PST to the lower speaking conductor, though. this o )cration would normally be without any pal 'icular ell ect. Moreover at armature 9 a circuit is completed for relay K and magnet SM in series and at armature 10 test wiper W of the switch DS is connected to the unction of: magnet SM and relay K. The switch Dbl thereupon commences to hunt in known manner to find a tree register translator, the tree condition being indicated by the absence of earth on the associated contact engaged by wiper W. When such a contact is found, no further circuit is completed for magnet SM and relay K is no longer short-circuited and accordingly operates, thereupon at armatures 12, 13 and 15 connecting'up wires W ll and Vi, at armature l-i preparing a new circuit for relay K, at armature 16 connec ing earth to wiper W to busy the seized register translator and at armature 1'? disconnecting busy tone and connecting up instead dial tone from lead DT over back con tact and armature 25. it may be mentioned that since the hunting action of the switch BS is very rapid, busy tone will normally be disconnected before the subscriber has had time to place the receiver to his ear and he will therefore hear dial tone to inform him that he may commence to dial. In case, however, for any reason no register translator should be available magnet Sh/l would continue to operate and if the subscriber was listenii'ig at this time he would hear the busy tone to warn him that the apparatus was not in a condition to respond to the impulses produced by his dial.

The earth connected at armature 16 to wiper ll is extended over lead 85 to relay H in the register translator and this relay accordingly operates, thereupon at armature 55 it connects earth to lead 80 to provide locking circuits for various relays as will appear subsequently, at arn'iatures 56 and 5? opens points in the homing circuit of the switch SS, and at

armatures

58 and 59 opens points in the homing circuit of the switch Moreover at armature 59 earth is extended from wiper 81 and the first contact in its bank through back contact and armature 8 and the lower winding of relay S to battery so that this relay accordingly operates. 'llhereupon at armature 66 it opens a point in the switching circuit, at armature (57 prepares a locking circuit for itself, at armature (58 propares a circuit for relay It, at armature ($9 disconnects wiper 82 and at armature 'ZO short-circuits the sending contacts 62, though this is for the present without etl'ect.

The subscriber on hearing the dial tone commences to dial the wanted number, and since as already explained he dials the first two letters of the eircl'iange name MUssley the corresponding digits will be 60. When the digit 6 is dialled, six interruptions are reduced in the circuit of line relay A and this relay Clo-energizes accordingly. Upon the first de-energization of relay ll, a circuit is completed as follows 1 earth, arn'iature 5 and its back contact, back contact and armature 19, armature 8 and its front contact, 'inature 12 and its front contact, wiper l l an d the contact on which it is standing, lead 232, armature 4L0 and its back contact, back contact and armature 5E2, winding of relay C, winding of magnet RM to. battery and parallel thereto, interrupter contact 53, back contact and armature 51, upper winding of relay F, armature 36 and its back contact, back contact and armature l9, resistance it) to battery. Relay l? a tweetsand at this time only operates its light armature 50 but not its armatures 49, 51 and 52. Moreover the magnet RM is energized and attracts its armature preparatory to advancing Wipers 71, 72, 73 and five others not shown into engagement with their respective next con tacts. Magnet RM also operates the contact 53 whereupon earth is removed from the junction of the two windings of relay F and this relay then ope "ates fully, there" pen at arma tures 4L9 and 51 opening its own initial energizing circuit and at armature 52 opening the initial circuit and preparing a further circuit for magnet RM. Magnet RM now de-energizes and effects the advance of the wipers of the switch SS and also closes its interrupter contact Relay F is now held operated in series with the magnet but the latter does not now operate. Relay C, it may be pointed out, is energized in the above-traced circuit and owing to its slow-to-release characteristic remains energized througl'iout the train of impulses. Accordingly at ari'nature 46 it co1npletes another point in the further circuit for magnet RM, at armature l? completes a circuit for relay Z, and at armature l8 opens a point in the circuit of relay L. Relay Z then operates and at armature 4.4- prepares the switching circuit, at armatin'e 45 closes a point in the circuit of relay ll and at armature 4L5 completes a circuit for the upper winding of the two-step relay X so that this relay operates its light armature 37 whereupon its lower winding is short-circuited. When relay A again energizes on the termination of the first impulse, a circuit con'ipleted as follows: earth, armature 5 and its front contact, back contact and armature 22, armature 13 and its front contact, wiper W and the associated bank contact, lead 33, front contact and armature 46, back contact and armature 36, front contact and armature 52, winding of relay C, winding of magnet RM to battery; consequently magnet RM again operates and prepares to advance the associated wipers a further step. The earth on lead 33 also serves to short-circuit relay F and this accordingly releases slowly. Owing however to its armatures being stiifly adjusted, it is arranged to release completely before earth is finally removed from lead 33 so as to secure the proper operation of magnet RM. It will be appreciated therefore that in response to the first impulse of the digit which is dialled by the calling party, the wipers of the switch SS have been advanced two steps. Similar effects are produced in response to each of the other impulses comprising the first series, and since this series consists of six impulses it will readily be seen that the switch SS advances its wipers a total of 12 steps in response thereto.

Upon the termination of this series of impulses, relay C de-energizes after a slight interval and at armature l7 opens the circuit of relay Z which de-energizes in its turn after a further slight interval. While relay Z holds up however, the following circuit is completed: earth, wiper 71, contact 87 on which it is now standing, armature 56 and its front contact, armature 4:8 and its back contact, front contact and armature 45, back contact and armature 38, winding of relay L to battery. Relay L thereupon operates, at armature 7 4 looks itself up to lead and at armatures 75, 76 and 77 connects up the second set of wipers (not shown) of the switch SS. lVhen relay Z falls away, at armature 4C5 earth is removed from the junction of the windings of relay X and it thereupon operates fully. At armature 38 it opens its initial energizing circuit, at armature 37 prepares a circuit for relay Y, and at armature 38 opens the initial energizing circuit for relay L. Moreover, at armature 36 it opens the circuit for relay F and the additional circuit for the magnet RM, so that the succeeding train of impulses shall advance the wipers of the switch SS only one step for each impulse instead of two.

When the subscriber dials the second digit 0, ton interruptions are produced in the circuit of relay A in the trunk relay group and at each interruption this relay de-energizes and transmits an impulse to the magnet RM over armature-5 and its back contact and the circuit previously traced.- The wipers of the switch SS are accordingly advanced a further ten steps making a total-of 22 so that they now stand on the 23rd contacts in their respective banks. Relay C operates as before and at armature 4C7 completes a circuit for effecting the partial operation of the twostep relay Y. When relay C de-energizes at the end of the train of impulses, earth is removed from armature 47 and accordingly relay Y now operatesfully, thereupon at armature 42 opening its initial energizing circuit, at armature 10 preparing the outgoing pulsing circuit over leads 32 and 33, at armature 43 completing a circuit for relay Z, at armature 13 connecting earth to lead 83 to start the sending operation, and at armature 39 completing a circuit which extends as follows: earth, back contact and armature at, front contact and armature 39, lead 34, contact and wiper V front contact and armature 15, armature 21 and its back contact, upper winding of relay D to battery. Relay D being a two-step relay, only operates armature 20 at this time thereby completing a locking circuit for itself to the release trunk conductor 4. Relay Z is slightly slow to pull up and consequently does not operate immediately, but when it does operate the above traced circuit is broken at armature 44 and relay D in the trunk relay group then operates fully, thereupon at armatures 18 and 9A preparing a locking circuit for relay A, at arinatures 1.9 and 22 opening the input pals ing circuit and completing the output pulsing circuit, at armature 21 transferring the switching circuit to relay E, at armature 23 transferring the locking circuit of relay K from. relay B to relay A and at armature 25 disconnecting dial tone from the lower speakin gconductor. The call ingsuhscriher will now pause for a moment while the re ister translater is sending out the translated exchange code and as soon as this is completed and it is in order for him to dial again, dial tone will he re-connected to the lower speaking conductor so as to give him the necessary signal.

Consideration will now be given to the sending operation taking place in the register translator. It will he assumed that the digits corresponding to the initial letters MO of the exchange Moseley are in this case translated into the digits 879. Accordingly the contacts on which the 6th, 'Zth and 8th wipers of the switch SS are now standing will. he cross-connected at the l. D. F. to

contacts

89 and 90 in the bank of wiper S2 and 91 in the bank of wiper 83 respectively. For instance lead 92 extending from the 23rd contact in the bank of the 6th wiper of the switch SS is connected to terminal on the left hand side of the I. D. F. whence a jumper extends to terminal 941 on the right hand side which permanently connected to contact 8?. It will be seen that upon the operation of relay Y, earth is connected to lead 88 at armature L3 and this then extends through the lower winding of relay R, armature 68 and its front contact and winding of magnet DM to battery. Assuming that the contacts of the interrupter I are open at this time, relay R now energizes but the magnet DM does not. Relay R at armature Get prepares a point in the switching circuit, at armature G l removes the shortcircuit from its upper winding, at armature closes a locking circuit for relay S and at armature 65 opens the initial. energizing circuit of this relay. lVhen the interrupter contacts next close the earth on lead 88 is extended over the interrupter I, back contact and armature 61, winding of magnet DM to battery. Relay R is thereupon shorted out and Clo-energizes while magnet DM now operates and attracts its armature preparatory to advancing the

wipers

81, 82 and 83 of the switch CS into engage ment with their respective next contacts. Magnet DM also opens the sending contact 62 but this is without effect at this time owing to the fact that this contact is at present shunted. by armature of the relay S. When the interrupter contacts next open, ntiagnet DM Clo-energizes, thereupon closing contact 62 and advancing

wipers

81, 82 and 83 one step. Relay S which had previously been held operated over the interrupter I is now tie-energized and at armature 70 renders the sending contact 62 operative in response to succeeding energizations of the magnet DM. This preliminary step of the sending switch CS is employed in order to make certain that a complete first impulse is sent over the outgoing trunk line, as it might happen that relay Y would be operated when the contacts of the interrupter l were ust about to open and accordingly/n mutilated impulse would then he sent out and this would pro] ably not operate the distant switches satisfactorily. An alternative method of obtaining the same result is to make use of a twostep relay which is operated by the first impulse and only in operated position connects the interrupter through to the magnet. It should he mentioned that relay It is slightly slow to pull up owing to its short-circuited upper winding, and thus cannot again energize before its circuit is opened at armature 68. It will. he seen that when armautre 68 engages its back contact, relays Q and it are connected in series but neither is able to operate in these circumstances.

W hen the interrupter contacts next close, the magnet BM again operated and at its contact 62 opens the circuit extending over the wipers l/V and ll of the switch DS and the outgoing trunk line to the distant switch and this is accordingly set in known manner. This operation then continues under the control of the interrupter until the switch GS has taken nine steps at which time eight impulses will have been sent outover the trunk line. When the wipers take their ninth step from normal, wiper 82 will engage contact 89 in its bank and a circuit will then he completed from earth; hack contact and armature 79, armature and its front contact over a lead eX tending to the sixth wiper of the switch SS, (which is not shown), lead 92, terminal 93 on the left hand side of the l. l). E, jumper to terminal 9% on the right hand side, contact 89, wiper 82, back contact and armature 86, back contact and armature 69, armature 68 and its back contact, winding of relay Q to battery. Relay Q, accordingly operates, at armature 61 disconnects the interrupter from the magnet DM and at armature 6O completes a circuit for the upper winding of relay S.

Relay S thereupon operates and at are ature 66 opens a point in the switching circuit, at

armature 67 prepares a locking circuit for itself, at armature 68 opens the circuit for relay Q, at armature 69 disconnects wiper 82 and at armatin'e YO short-circgits the sending contact 62, though this is without effect at the present time. Moreover at the front contact of armature 68 a circuit is again completed from battery through tile winding of magnet PM for relay R, and it energizes with the results previously described. Relay Q commences to de-energize when its circuit is opened at armature 68 but owing to the slug on its core does not fall away at once. hen it does so, however, the initial circuit of relay S is opened and it is then maintained from earth supplied by armature 65. When the contacts of the interrupter I next close after armature 61 re-engages its back contact, relay R is shorted out and de-energizes and at the same time a circuit is again completed for the magnet DM which accordingly operates.

,When relay R Clo-energizes and falls away,

relay S is maintained as before ever the interrupter, back contact and armature 61, normally closed springs controlled by armature 65, and front contact and armature (S7. Accordingly relay S remains energizedv until the interrupter contacts again open whereupon it de-encrgizes and at armature removes the short from the sending contacts 62 so that they are again operative to control the distant switches in the speaking circuit. Moreover, owing to the de-energization of the magnet DM, the wipers of. the switch OS are advanced a further step. The pause represented by the time which relay Q takes to fall away together with the time for the switch CS to take one step is sufficient to permit the switch which has just been operated in the speaking circuit to complete its hunting operation and take into use a succeedii 7 switch which then responds to the n ext series of impulses. After relay S falls away, the magnet DM is operated intermittently under the control of the interrupter I and serves to send impulses as previously described by means of its interrupter contact 62. The second digit in this case is 7 so that after the switch has taken a total of eight steps from the position in which. the previous series of impulses was terminated, wiper 82 will engage contact 90 which is suitably cross-connected so as to obtain earth over back contact and armature 78, armature 76 and its front contact and the seventh wiper of the switch SS. Accordingly a circuit is completed for relay Q as before and this operates to terminate the impulse sending and to complete a circuit for relay S. Relay S operates in its turn and disconnects wiper 82 and completes a circuit for relay R, at the same time opening the circuit of relay Q. Consequently after its slow period relay Q de-energizes and again connects up interrupter I and the switch CS then takes its preliminary step with relay S energized.

When relay S falls away after this step, the sending of the third series of impulses commences this series comprising; 9 impulses. This operation takes place in the manner previously described but it will be seen that after six impulses have been sent out, wiper 81 will engage the last contact in its bank and that a circuit is then completed from earth, wiper 81 and the last contact in its bank, armature 59 and its front contact, armature and its back contact, lower winding of relay '1 to battery. Relay T is a two-step relay and at this time operates its light armature 84 thereby short-circuiting its upper winding by earth on lead 88. When wiper 81 steps off this contact, the initial circuit for relay T is opened and it then operates fully, thereupon at armature 84: opening the initial circuit of relay S, at armature 85 opening its own initial energizing circuit and at armature 86 disconnecting wiper 82 and connecting up wiper 83 instead. When the wipers of the switch CS have taken two further steps, nine impulseswill have been sent to the switch in the speaking route and wiper 83 will then engage contact 91 whereupon a circuit is completed as follows: battery, armature 7'7 and its front contact, eighth wiper of the switch SS, lead 95, terminal 96, jumper to terminal 97, contact 91, wiper 83, front contact and armature 86, back contact and armature 69, winding of relay R to earth on lead 88. Relay R accordingly operates and at arn'iature 64- completes a switching circuit which extends as follows: earth, back contact and armature 66, armature 64: and its front contact, front contact and armature 44, front contact and armature 39, lead 3d, contact and wiper W front contact and armature l5, armature 21 and its front contact, normally closed springs controlled by armature 28, winding of relay E to battery. Relay E therefore operates, at armature 27 switches the release trunk conductor through, at armature 28 completes a locking circuit for itself and removes one of the earths for maintaining relay D operated, at armature 29 opens the circuit of relay K so that this de-energizes and frees the register translator, at armature 30 again connects up dial tone to indicate to the calling subscriber that he may now dial the numerical digits 2345 in the wanted numher and at armatures 26 and 31 connects the speaking leads through at the same time opening the original energizing circuit of the re lay A. Relay A, however, is now held up over arn'iatures l8 and 24- of relay D and it will be noted that relay D is held up over arniature 6 of relay A. WVhen relay K deenergizes, earth is removed from lead 35 at armature l6 and accordingly relay H in the register translator de-energizes also, thereupon at armature 55 removing the holding earth from relays X, Y, L. Upon the release of relay Y, relay Z is released and earth is removed from lead 88, this serving to bring down relays T and R. Moreover owing to the release of relay H, a circuit is now completed from earth on wiper 71 over armatu cs 56 and 57 and interrupter contact 54 for m agnet RM and this then operates under the control of contact 54L- to restore the wipers of the switch SS to normal position. Furthermore when

armatures

58 and 59 engage their back contacts a similar restoring circuit is completed over wiper 81 and interrupter coir tact 63 for the magnet DM and accordingly the wipers of the switch CS also are restored to normal. All the apparatus in the register ill controller has now been returned to its normal position and the register translator may be taken into use for completing another call.

The subscriber will. now dial the first digit 2 in the numerical designation of the wanted party and two impulses will thereupon be produced inv the circuit of the line relay of the last switch seized. Moreover the circuit of relay A in the trunk relay group will be interrupted and accordingly it will release its armature 6 thereupon opening the circuit of relay D. Relay D then (lo-energizes and at armatures 18 and 24 disconnects relay 1%.

hat neither relay D nor relay A can again be energized. l/Vhen relay A finally falls away, the circuit for relay B is opened and this de-energizes thereupon at armature '5 removing one earth connection from the release trunk conductor and at armature ll finally removing dial tone from the calling partys line so that he shall not be annoyed while conversation is in progress. Relay E in the trunk relay group is now held up over eartl'i fed back over the release trunk conductor an d thus only Clo-energizes when the connection is terminated, whereupon al the apparatus of the trunk relay group is restored to normal.

It may be pointed out at this time that in case the calling party should commence to dial a numerical digit befor the exchange code has been sent out from the register translater, and hence before the operation 01 relay E, when relay A (lo-energizes the holding circuit for relay K is opened at armature 5 and accordingly relay K falls away and releases the register translator in the manner just described. Moreover at arn'iature 17 busy tone from the lead ET is again connected up since relay E is not operated and thus the subscriber will be informed that he has operated the apparatus improperly and will therefore be unable to obtain his connection.

In order that the operation of the improved register controller may be fully appreciated, another typical connection will now be traced through briefly. It will be assumed in this instance that the subscriber requires the number Landale 23%5 and accordingly dials the digits 52 corresponding to the letters LA oi the exchange name. From what has already been. said it will be understood that in this case the wipers of the switch SS will be advanced 10 steps in response to the first digit 5 and then two steps in response to the second digit 2, that is to say a total of 12 stops. it will also be assumed that in this case the digits 52 are translated to the digits 26.

ll hen the subscriber removes his receiver, his line switch seizes a tree trunk relay group, for instance that shown, whereupon relay ii. operates in the usual manner and energizes relay B which initiates the hunting movement of the switch DS to associate a tree register translator with the trunk relay group taken into use. lllhen relay 1*: operates on the seizure of the register translator, the busy tone previously connected to the line is remover and dial tone is substituted so tliat the sub scriber then lrnows that he may commence t dial the wanted number. ll hcn the 5 is dialled, relay 0 is opcr owing to the interactimi or relay ll and magnet Ell /l, the latter is operated twice as many times as there are impulses in the series. At the end oil the first series or in'ipulses a momen tary test is made while relay Z holds up to ascertain whether relay L shall be operated or not. In this e: se it is desirable that this relay shall not be operated and inspection of? Fig. 2 will show that since wiper T1. is new StitlKlifflf? on its thirteenth contact no circuit is completed for relay L which means that the first set of wipers in the switch 53S are to be employed for marking suitable contacts in the bani: ot the switch S. fi hen the succeeding series of two impulses is dialled, the wipers of the switch are advanced a further tw steps, that to say in this case a number of steps corresponding to the number of impulses dialled since the auxiliary circuit of the magnet RM is now open at armature 36. W hen relay C de-energizes at the end of this series of in'ipulses, relay operates and by )1. connecting earth to leac 88 starts the sending operation. l l hen earth is connected to lead 88, a circuit is also completed over wiper '22 and contact 98 on. which. it is new standing for relay M and this relay at armature '58 then connects battery to armature 76 in place of the normal earth connection; the purpose of this connection will be apparent shortly. litelay S is again operated as soon as the register controller is taken into use since relay ll then operates and completes its circuit armatin'e 59. When earth is applied to lead 88, the switch CS is started stopping and after it takes the first step, the circuit tor relay 3 opened and impulses are subsequently transn'iitted over the outgoing trunk line by the interrupter contact 62. Since the first series oil outgoing impulses is to comprise two impulses, it will be seen that the switch CS will. take three steps, the first one not being eli cctive since the contacts 62 are shunted at thitiine. When wiper 62 engages contact 100, i finds earth which connected up by way or arinatures 79 and 75, wiper 72 and contact 99 so that a circuit is completed for relay This relay upon energizing, before cuts oft the interrupter l and. energizes relay S which in its turn pulls up relay ll. After a pause due to the slow period o't relay and the time taken for the switch US to make one idle step, the sending of the next series impulses commences, and since this series is to comprise s12; impulses it will terminate when wiper engages contact 101. @wing, however, to the operation of relay M, wiper 82 now finds battery instead of earth, this indicating that the last series of impulses has been transmitted and that the switchin impulse is now to be transmitted from the register translator to the trunk relay group. In response to this battery connection, relay It operates but in this case neither relay Q nor relay S, hence earth is connected to lead as to bring about the release of the register translator as previously described.

It may be pointed out that thou ghtwo banks are provided on the switch CS so as to give 50 points for sending control, i. e. facilities for sending out as many as 5 exchange code digits, itmight well. be that in a system of the size contemplated such an arrangement would be unnecessary and one bank only would snliice. Clearly it more than three exchange code digits are required special arrangements must be provided for connecting up the required number of wipers of the switch SS. In case the exchange code should not comprise as many as 3 digits, either relay M or relay N would be operated when the switch SS was fully set, and by connecting up battery earlier would terminate impuls sending at the proper time. It will be understood that in case an exchange code of only one or two digits was most often required this could be arranged to be sent normally without the ope "ation of either relay M or relay N.

What I claim as new and desire to secure by Letters Patent is 1. In a multi-otlice telephone system wherein register translators are provided for regis- 2. In a telephone system wherein calls are set up from calling lines over trunk lines and wherein a register controller is temporarily connected to a trunk line through a plurality of leads to enable the register controller to be set from the calling line and to enable automatic switching mechanism to be operated by the register controller to further extend a connection, means for transmitting impulses from the calling line to the register controller over a given conductor in the connection between the register controller I and the trunk line, and switching means for inchiding said given conductor in the circuit over which the impulses are transmitted out quent series.

of the register controller to the automatic switches. I

3. In a register controller for use in telephone systems to receive a plurality of digits in a called number and to retransmit impulses corresponding thereto to control automatic switches, a single motion switch, and means for advancing the wipers of said single motion switch to a given position to register a digit in a number, and for advancng said wipers from said given position in response to a subsequent digit and to an extent depending upon the value of the last named digit.

l. In a register controller for use in telephone systems, a registering device arranged to respond. to two series of impulses, and means whereby the registering device advances a plurality of steps for each impulse of the first series and advances a different number of steps for each impulse of a subse- 5. In a register controller for use in telephone systems including a stepby-step registering device responsive to a plurality of series of impulses, means whereby the registering device is advanced a' given number of steps responsive to a given train of impulses and is advanced a ditlerent number of steps responsive to a subsequent train of impulses of the same value.

6. In a register controller for use in telephone systems wherein a plurality of digits are reg stered on a single motion step-by-step registering device of the adding type wherein the second movement of the registering device is added to the first movement to constitute single sum-total movement from normal position, means for lessening the likelihood oi the receiptof ditlerent digit combinations resulting in the same sum total movement, said means constituting an arrangement for causing the device to advance two steps for each impulse in the first series.

7. In. a register controller for use in telephone systems and including a register switch having a plurality of wiper sets, means for advancing all of the wiper sets responsive to and in accordance with the value of each of a plurality of digits tobe registered, and means for selecting a set of said wipers in accordance with the extent of the movement 01 the several wiper sets responsive to the first digit.

8. In an impulse sending device for use in telephone systems and employing a rotating counting switch for counting and controlling the number of impulses in the various trains of impulses transmitted, means for always advancing the counting switch the same number of steps between the transmission of two successive trains of impulses.

9. In an impulse sender for use in telephone systems wherein a rotating counting switch is provided to count and terminate series of impulses, means for advancing said counting Switch step by step during the counting operation, means for terminating a series of impulses responsive to said switch reaching a predetermined position, and means whereby said switch is maintained in said predetermined position for a specified length of time following the termination of a series of impulses and is again advanced from said predetermined position at the end of such interval pursuant to the counting of the next series of impulses.

10. In a. multi-oflice telephone system in which a register sender is temporarily connected to a connection to be established from a calling automatic line and in which registering apparatus is provided in such register sender for registering only the oflice designating portion of the number and for retransmitting the necessary digits to trunk the call to the desired ofice, arrangements being provided for disconnecting the register sender from the partly established connection and for placing the further extension of the connection under the control of the calling line after the register sender has completely functioned, means for informing the calling subscriber over the calling line when the further extension of the connection has been placed under his control.

11. In a telephone system as set forth in claim 10, means effective in case the calling subscriber attempts to exercise a further control over the established connection before the register sender completes its operation for releasing the partly established connection zltnd for placing a special tone on the calling 12. In a telephone system as claimed in claim 10, means for placing a dial tone on the calling line before the register sender has been set informing the calling subscriber that he may now set the register sender, and means for removing the dial tone after the calling subscriber commences to set the register sender and for subsequently reconnecting the dial tone to the calling line to serve as the said signal for indicating that the calling subscriber may control the further extension of the connection.

18. In a multi-oflice telephone system wherein register translators are provided for registering the ofiice designations of calls and for retransmitting impulses to direct calls to the respective desired oflices, registering apparatus in each register translator for receiving the oiiice designating portion of a called number, and means for preventing in all cases the retransmission of directive impulses other than those retransmitted in ac cordance with the ofiice registering apparat-us.

14. In a multi-oflice telephone system wherein register translators are provided for registering the office designation of calls and for retransmitting impulses to direct the call to the respective desired offices, means effective after all the resulting impulses have been transmitted by the register translator for freeing the register translator and for placing the extension of the connection in the called office under the control of the calling line, and means responsive toan attempt of the calling party to exercise further control after he has caused the office designation to be registered and before the said freeing has been accomplished for immediately freeing the register sender.

15. In a multi-office telephone system in which a register senderis temporarily connected to a connection to be established from a calling line and in which registering apparatus is provided in such register sender for registering a portion of the number and for ret-ransmitting the necessary digits to trunk the call to the desired office, arrangements being provided for disconnecting the register sender from the partly established connection and for placing the further extension of the connection under the control of the calling line after the register sender has completely functioned, means for applying a source of tone current to the partly established connection in the originating ofiice, regardless of to what oflice the connection has been extended, to inform the calling subscriber that the further extension of the connection has been placed under his control.

16. In a multi-office telephone system in which a register sender is temporarily connected to a connection to be established from a calling automatic line and in which registering apparatus is provided in such register sender for registering a portion of the number and for retransmitting the necessary A digits to trunk the call to the desired office, arrangements being provided for disconnecting the register sender from the partly established connection and for placing the further extension of the connection under the control of the calling line after the register sender has completely functioned, and means for applying a tone source to the calling line over a circuit path independent of the portion of the conection extended under the control of the register sender for informing the calling subscriber that the further extension of the connection has been placed under his control.

In testimony whereof I have signed my name at London, England, this 11th day of January, 1927.

FRANK TEN CH.