US1889107A

US1889107A - Telephone system

Info

Publication number: US1889107A
Application number: US465901A
Authority: US
Inventors: Edward S Peterson
Original assignee: Associated Electric Laboratories Inc
Current assignee: Associated Electric Laboratories Inc
Priority date: 1930-07-07
Filing date: 1930-07-07
Publication date: 1932-11-29
Anticipated expiration: 1949-11-29

Description

Filed July '7, 1930 3 Sheets-Sheet Inuenlor "d 5 Fe ersun Edwa Nov. 29, 1932. E. s. PETERSON TELEPHONE SYSTEM Filed July 7, 1950 3 Sheets-Sheet 2 Tnuen c1r- E dward 5. Fe arson Nov. 29, 1932. E. s. PETERSON TELEPHONE SYSTEM Filed July 7, 1950 3 Sheec's-Sheet 5 1 mm Edward 5P2 arson fi /7 Z l Nov. 29, 1932 UNITED STATES PATENT OFFICE EDWARD S. PETERSON, OF CHICAGO, ILLINOIS, AS SIGNOR, BY MESNE ASSIGNMENTS, TO

ASSOCIATED ELECTRIC LABORATORIES, INC., OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE TELEPHONE SYSTEM Application filed July 7, 1930. Serial No, 465,901.

This invention relates in general to telephone systems and in particular to automatic telephone systems in which connections may be established through the medium of subscriber controlled step-by-step switches. More particularly the invention is concerned with a system of the above character which is combined with or has superimposed on it, so to speak, a special signalling or messenger call service system; and the broad object of the invention may be said to be the provision of new and improved auxiliary apparatus for use in connection with a telephone system.

it is an object to provide a telephone system in which certain subscribers in addition to being able to establish regular telephonic service with other subscribers, may, by dialling a special number signal a telegraph ot- 'fice, thereby dispensing with the usual messenger call boxes which require separate lines to the telegraph oifice.

A special object is the provision of means whereby all subscribers provided with the special services may dial the same particular number and immediately upon hearing a tone, replace the receiver, whereupon the auxiliary equipment operates to permanently record the number of the calling subscriber at the telegraph office, so that a messenger may be dispatched to the subscriber.

A feature of the invention resides in providing a special booster battery connection back over the switch train of the connection,

when a subscriber calls the special number,

in order to initiate the operation of the auxiliary apparatus.

Another feature resides in providing a group of relays individual to each special 40 subscriber, which operate to control the auxiliary apparatus in a manner to make a record of the number of the associated subscriber at the telegraph office.

The above objects and features, together with others which will be apparent hereinafter. Wlll now be described in detail, refer-- ones being had to the accompanying drawings comprising Figs. 1, 2 and 3 which show by means of the usual circuit diagrams sufficient of the apparatus employed in a system embodying'the principles of the invention to enable the same to be easily understood.

Referring to the drawings, which should be placed with Fig. 2 to the right of Fig. l and Fig. 3 below Fig. 2, the subscribers substations A and A Fig. 1 are the ordinary automatic substations having the usual talking, signalling and impulse transmitting instrumentalities. The lineswitches LS and LS are mechanically of the well known rotary type in which the wipers have no normal position and move in a forward direction only. The selector switch S and the connector switch CN, shown in skeleton form, are mechanically of the well known Strowger vertically and rotary type in which the bank contacts are arranged in horizontal rows or levels. The group of relays RG is one of a number which are seizable by the selector S when its wipers are raised to a special level of bank contacts.

Fig. 2 shows two groups of relays, SR1 being individual to substatlon A and SR6 individual to substation A. These relay groups start the operation of the auxiliary apparatus and also determine the three-digit number or code of the associated substation which is to be transmitted to the telegraph olfice. The cut-ofl? switch CO determines the number of times the code is to be sent to the telegraph office and is a rotary step-by-step switch in which the wipers move only in a forward direction each time the armature of its magnet retracts its armature.

Fig. 3 illustrates the code sender switch CS which is of the same construction as the cutoil switch CO. This code sender switch together with the associated group of control relays operates to transmit the three digit code or number of a calling substation, over a trunk line extending to the telegraph ofice where the punch register PR is operated.

The system having been described in general a detailed description will now be given of its operation. For this purpose it will be assumed that the subscriber at the substation A desires to establish an ordinary telephone connection with the subscriber-at substation A. Upon the removal of the receiver at the substation A a circuit is completed for line relay 15 of the lineswitch LS and over the line conductors 5 and 6. Line relay. 15 upon energizing closes acircuit for the switching relay 10 and rotary magnet 25 in series at armature 16, and at armature 17 connects the test wiper 19 to a point midway between the switching rela 10 and stepping magnet 25. A branch of t e ground circuit from armature 16 extends over conductor 14 to the connector bank to maintain the line busy at this time. A branch of conductor 14 extends to relay 100 of Fig. 2, but due to its high resistance it cannot energize at this time. From this point the operation depends upon whether the selector S or other selectors connected to the bank contacts of the lineswitch LS are busy or idle. If the selector with which wiper 19 is engaged is busy, ground will be extended over wiper 19, armature 12 and its back contact, armature 17 and its front contact, back contact of armature 26, through the windin of the stepping magnet 25, to battery. T e switching relay 10 is thereby short-circuited and the stepping magnet 25 is operated in the manner of a buzzer to rotate the

wipers

18, 19 and 20 over their associated bank contacts. As soon as an idle selector, such as S, is encountered, ground potential will no longer be present on the test wiper 19, and therefore the switching relay 10 is no longer short-circuited and it energizes in series with the stepping magnet 25. However, owing to the high resistance of the switching relay 10, the stepping magnet does not operate in series with it. Switching relay 10 upon energizing disconnects the test wiper 19 from its armature 12 and its back contact and connects it directly to the private normal conductor 14.

As a further result of its energization switching relay 10 disconnects the circuit of the line relay 15 from its armatures 11 and 13 and then connects the line conductors 5 and 6 directly through to the wipers 18 and 20, and over conductors 21 and 23, armatures 51 and 54 and their back contacts to battery and ground through the upper and lower winding of line relay 30 of the selector S. Line relay 30 upon energizing closes a circuit for slow-release relay 35 from its armature 31 to ground at armature 53. At armature '36 relay 35 upon energizing extends ground over the release trunk conductor 22 to render the selector busy, and at armature 37 the circuit for series relay 40 and vertical stepping magnet 55 is prepared.

The calling subscriber A now operates his calling device S in accordance with the first digit of the desired number, thereby producing a series of interruptions in the circuit of the line relay 30 of the selector S. As soon as the line relay deenergizes in response to the first of these interruptions it completes a circuit from ground on armature 53, armature 31 and its back contact, armature 37 and its front contact, through the winding of the series slow-release relay 40 and the winding of the stepping ma net 55, to battery. Slow-releaserelay 40 and the stepping magnet 55 energize in series over this circuit and the vertical magnet upon operating raises the wipers 61, 62 and 63 of the selector one step opposite its first level of bank contacts, whereupon the oil-normal springs 58 and 60 immediately operate. As a result of the closure of the off-normal spring 58 a circuit is completed from ground at release conductor 22, armature 41 and its front cont act, through the ofi-normal springs 58, contacts 57. through the winding of the stepping relay 45, to battery. At armature 46 relay 45 completes a locking circuit for itself and at armature 47 prepares a circuit for the rotary magnet 56. Relay 40 remains energized as also does relay 35 between impulses of a series.

The remaining impulses of the series operate the vertical magnet 55 to raise the wipers opposite the desired level of bank contacts, and shortly after the last impulse slowrelease relay 40 will deenergize and close a circuit for the rotary magnet 56 and its armature 41. Rotary magnet 56 upon energizing rotates the wipers 61, 62 and 63 into engagement with the first set of bank contacts of the level, and at its armature 57 o ens thecircuit for the stepping relay 45. tepping relay 45 upon deenergizing opens another point in its circuit at armature 46, and at armature 47 opens the circuit of the rotary magnet 56, and this magnet upon deenergiz ing again closes its armature 57 to prepare a new circuit for stepping relay 45.

From this point the operation depends upon whether the first trunk line terminating in the first set of contacts in the bank is busy or idle. If it is busy stepping relay 45 energizes again over a circuit extending from ground by way of the test contact with which wiper 62 is in engagement, armature 52 and its back contact, closed off-normal springs 58, armature 57 and through the Winding of relay 45, to battery. This relay upon again energizing closes a locking circuit for itself at armature 46' and at armature 47 again completes a circuit for rotary magnet 56. This alternate operation of the stepping magnet and the rotary magnet continues so long as test wiper 62 engages grounded contacts.

I will now assume that the trunk line extending to the connector switch ON is idle, and that being the case the wipers 61, 62 and 63 of the selector will arrive on

bank contacts

67, 68 and 69 as there is no longer ground potential upon contact 68 the stepping relay 45 no longer energizes. The switching relay 50 is no longer shunted and it energizes from ground on the release trunk conductor 22, through the winding of switching relay 50, off-normal contacts 58, armature 57 and in series through thewinding of the relay 45.

Ill

to battery. The stepping relay 45, however, does not energize in this circuit due to the high resistance of switching relay 50. Relay upon energizing removes ground from armature 53 so that slow-release relay 35 will deencrgize, and at armature 52 disconnects the-test wiper 62 from the point between the switch'ng relay 50 and stepping magnet 45 and connects it instead to ground by way of the release trunk conductor 22 at armature 36, thus making the trunk line busy immediately, and at armatures51 and 54 disconnects the trunk conductors 21 and 23 from the windings of line relay 30 and extends them by way of the front contacts of these armatures, wipers 6'1 and 63, bank contacts 67 and 69, over the trunk conductors to the line relay of the connector CN. The connectorCN thereupon operates and places ground upon the release trunk conductor 22 to establish the usual holding circuit for the selector S and the lineswitch LS before slow-release relay .35 of the selector S has time to deenergize.

The calling subscriber now operates the calling device S in accordance with the second digit of the called number. The connector CN is thereby operated'to raise its wipers to the desired level of bank contacts. The subscriber then dials the third or final digit of the called number and as a result the connector rotates its wipers into connection with the line extending to substation A, and in the usual manner upon the completion of the connection the called line is signalled to notifythesubscriberthathe is wanted. When the called party answers the conversation will proceed and when'it is completed the sub scribers will replace their receivers, bringing about the release of the connection in the usual manner. As the foregoing operation of the connector switch UN is well understood it is not thought necessary to further describe its operation in detail, except to state that upon the release of the connection the connector switch CN removes the holding ground from release trunk conductor 22, which likewise opens the circuit of the switching relay 50, so that this relay upon deenergizing will close a circuit from armature 53 through armatures 31 and 37 off-normal springs 60 and then through the winding of the release magnet 59, to battery. The release magnet upon energizing restores the wipers of the selecting switch S to normal. The lineswitch LS is also restored to normal by removing the ground from the release trunk conductor 22 which held the switching relay 10 energized and as ground is no longer encountered on the busy guarding circuit 14 the subscriber at substation A is available for any incoming calls.

The foregoing describes an ordinary telephone connection which may be established between any two subscribers in the system,

system having the messenger service available or who subscribes for this service.

.Upon the removal of the receiver at the substation A the lineswitch' LS operates, as has been explained, to seize an idle selector switch S and when one has been found the subscriber dials a particular number so that the wipers of the selector are elevated opposite a particular level of bank contacts, over one of which a number of relay groups, such as RG, may be reached. When an idle relay group, such as RG, has been seized by the selector S the wipers 61, 62 and 63 will be positioned upon

bank contacts

64, 65 and 66, and the relay 7 5 will become ener ized from battery through its upper winding, line conductor 21, line conductors 5 and 6, of the substation A, line conductor 23, through the lower winding of relay 75, to ground, through the primary winding of the tone machine T. The subscriber at substation A will hear a tone in his receiver, which is generated by the tone machine T, and thereby become aware of the fact that his line has been connected with the auxiliary signalling equipment and that the telegraph office will be signalled for a messenger who will be promptly dispatched to the subscribers premises. If the subscriber after hearing the tone, desires, he may immediately replace his receiver upon the switchhook, thereby automatically releasing the selector switch S and the lineswitch LS to normal, so that this equipment will be available for other calls or for another call by the same subscriber to another subscriber.

Relay 75. of the relay group RG upon energizing, at its armature 7 6 and its front contact closes a locking circuit for itself from ground at alternate front contacts of armature 81 so that this relay will remain energized in case the subscriber A should immediately replace his receiver and release the connection upon hearing the tone from the tone machine T. As a further result of the energization of the relay 7 5 it attracts its armature 77. This armature, it may be explained, is of a type which has a weight attached to one end of it so-that it will vibrate r'or a certain length of time before coming completely 'to rest onto its front contact, whereupon a circuit is completed from ground through this armature, through the winding of slow-to-pull-up relay 80, to battery. At armature 78 and its front contact, relay 75 momentarily connects the booster battery B to the conductor 90. This booster battery B, it may be explained, is of slightly higher voltage than the ordinary batteries indicated on the relays in the drawings and has the effect of boosting or assisting these batteries. This booster battery is thereby extended momentarily throu h the resistance, the alternate contacts of armature 78, conductor 90, bank contact 65 and wiper 62 which is resting upon it, armature 52 and its front Contact, release trunk conductor 22 extending through the selector S, wi er 19 of the line switch LS, armature 12 an its front contact, conductor 14, (which is grounded when the switches are in use to prevent other calls from coming in on them over conducfor 14) Fig. 2, through the winding of high resistance relay 100, to battery. The high resistance relay 100 ordinarily will not energize from round over the release trunk conductor 14, but as in this instance the booster battery B is connected to this conductor this relay will energize. 7

Referring back to the operation of slowto-energize relay 80, the armature 82, after armature 78 has been completely attracted and disconnected the booster battery B from its alternate contacts, will extend ground to release trunk conductor to maintain the relay group RG in a busy condition. At armature 81', relay 80 disconnects the locking ground from relay 75, so that if the subscriber has released the connection it will become deenergized and at armature 77 upon falling away open the circuit of slow-toenergize relay 80 and when this relay retracts its armatures the relay group R will now be in its original normal position.

Referring now to Fi 2 it may be stated that the relay group R1 is individual to the subscriber at substation A while the relay group SR6 is individual to the substation A and a relay group, such as SR, is therefore individual to each station in the telephone system which has available the messenger call service. The

multiple conductors

128, 129, 130, 131 and 132 extending to the top of this figure connect to similar relay groups in the same manner as the relay groups SR1 and SR6, and the purpose of these relay groups it may be stated is to set up a number which is individual to its associated substation on the banks of the code sender OS, Fig. 3. Another purpose is to prevent the operation of the code sender CS by any other relay group, such as SR6, while the code number of one substation is being transmitted to the telegraph oflice. In other words the equipment temporarily stores up the code number of its associated substation until the code sender and its auxiliary equipment is available.

Returning now to the operation of the high resistance relay of the station relay group SR1, it will be recalled that this relay was energized momentarily froin the booster battery B extending over a circuit from the relay group RG, through the selectorS and the lineswitch LS and over the conductor 14.

At grounded'front contact of armature 101,

relay 100 completes a circuit through the winding of relay to battery, and this re- Iayupon energizing closes a locking circuit for itself extending from ground on back contact and armature 113, front contact and armature 108, through the winding of the relay to battery, so that this relay remains locked up even though the high resistance relay 100 is deenergized, due to the hanging up of the receiver at the subscribers station A. At front contact and armature 107, relay 105 prepares a circuit for relay and at armature 106 and its back contact it opens a chain circuit extendin in series through all of the station relay R groups, so as to prevent any other station from operatin the code sender equipment while the code 0 the instant station is being transmitted. At front contact and armature 106 a circuit is prepared for relay 115, extending from battery through the resistance at armature 141 and its back contact, conductor 130, upper winding of relay 115, armature 111 and its back contact, front contact and armature 106, conductor 132, to ground at back contact and armature 157. Relay 115 accordingly energizes over this circuit and completes a locking circuit for itself through its lower winding, extending from ground on back contact and armature 113, armature 117 and its front contact, lower winding of relay 115, conductor 131, through the winding of relay 140, to battery. At its armature 116 relay 115 prepares a circuit for relay 110, while at its

armatures

118, 119 and 120 and their associated front contacts the particular or special code number 384 assigned to substation A is set up on the bank contacts of the code sender OS, by way of the conductor 128.

At the time relay energized it completed an obvious circuit at front contact and armature 141 for relay 145, and this relay upon energizing closes ground from its front contact and armature 146 over conductor 142.

through the winding of relay 225, to battery,

Fig. 3.

Before proceeding further with a detailed description of the apparatus and code sender of Fig. 3 it may be stated that this switch is mechanically of the same construction as the cut-off switch CO, in that the stepping magnet 240 rotates the

wipers

250, 251, 252 and 253 in a forward direction step-by-step over their associated bank contacts. The arrangement of the bank contacts and the wipers is such that a pair of wipers, such as wipers 252 and 253, simulate a 50 point switch and in order to reduce the cost a standard 25 point bank has been provided in each case, and the operation is such that imfirst half of the bank contacts overwhic'lr wiper 253 rotates is arranged to pick-up the first digit of the codenumber, while the last half of this bank will pick-up the seconddigit of the code number. Similarly wiper 252 will engage a particular bank contact in the first half of its bank to pick-up the third and final digit of the code number. In actual practice the code digit conductors extending from the bank contacts over which wipers 252 and 253 rotate would be connected to an intermediate distributing frame, so that the code conductors extending from the station relay group, such as SR, could be cross connected for any desired number. In this manner additional stations may be added or existing ones changed as desired. In accordance with the above for the purpose of illustration the station relay group SR1 is arranged to set up the code digit number 384 on the bank contacts of the code sender. Conductor 121 therefore extending to digit number 3 on the first half of the bank over which wiper 253 rotates, conductor 122 ex tending to code digit conductor 8 in the last half of the bank, while conductor 123 extends to number 4 code-digit conductor in the first of the banks over which wiper'252 rotates. In a similar manner the station relay group SR6, which is individual to substation A is arranged to set up the code number 965 on the banks of the code sender.

Returning now to the operation of relay 225 of Fig. 3 at the time it was operated from ground on armature 146 of relay 145, this relay upon operating prepares a circuit for slow-release relay 230 at armature 228, at

armature 229 it prepares a shunting circuit for relay 220, while at armature 219 it pre pares a circuit for starting the code sender switch CS extending over

armatures

226 and 227 as will now be pointed out; ground on armature 219 and its front contact, armature 226 and its front contact, wiper 253 and bank contact 259 upon which it is normally resting, armature 227 and its front contact, through the winding of relay 220 and the non-inductive resistance, to battery. Relay 220 upon energizing closes a locking circuit for itself over its front contact and armature 221 to ground at armature 219, while at armature 222 it prepares a circuit for operating the printing recorder PR at the telegraph office over

conductors

223 and 224. A branch of the circuit extending from ground at armature 219 and its front contact, likewise, extends to armature 216 and its back contact, through the winding of slow-to-energize relay 210, to battery. The battery through the resistance extending to the other side of the windingofthis relay is for the purpose of making this relay a. slight amount slower to pull-up, because part of the currentis shunted through the resistance and also for preventing excessive sparking at armature 216.

After an interval the relay 210 closes its armature 211 onto its front contact and completes the circuit for slow-to-energize rela 205.

elay 205 upon operating closes its armture 206 onto its front contact and completes a circuit extending from ground at armature 219 and its front contact, armature 206 and its front contact, armature 231 and its back contact, back contact and armature 232,

through the winding of relay 215, to battery.

Relay 215 upon energizing opens the circuit of slow-to-pull-up relay 210 at back contact and armature 216. Relay 210, after an interval deenergizes and opens the circuit for slow-to-pull-up relay 205 at armature 211, and after a slight interval relay 205 retracts its armature 206, so that the circuit for relay 215 is interrupted. Relay 215 upon falling away again completes a circuit for slow-topull-up relay 210 and the cycle of operation is again repeated, as long as armatures 231 and 232 remain at normal. Each time that relay 215 energizes it completes a circuit over the

trunk conductors

223 and 224 to the printing recorder PR at the telegraph ofiice,

from ground on armature 219 and its front I ing recording relay PT, back over trunk con-' ductor 224, to battery at the exchange. Each time the printing recording magnet PR energizes it operates'its armature to print a dot or make a perforation in the moving tape. Each perforation corresponds to an impulse and a series of these perforations will correspond to a particular number or digit of the code. The operation of this printing recorder is. well known in the art and it is not thought necessary to further describe its operation.

- A branch of the original energizing circuit of relay 215 extends by way of the back contacts of armatures .231 and 232, through the winding of the stepping magnet 240, to battery, so that each time 'the relay 215 is energized the stepping magnet 240 likewise receives an impulse of current. Accordingly,

step onto their second bank contact. The

' secondbank contactupon which wiper 251 is now resting is grounded but this has no 'effeet at this time because relay 225 is energized and maintains armature 228 away from its back contact. As the wiper 253 is now resting on its second bank contact the conductor #1 connected to this bank contact has no potential connected to it at this time and no action takes place. Accordingly, the ste ping magnet 240 continues to --rotate t e wipers step-b'y-step under control of the repeated slow operations of the relays 205, 210 and 215, until wiper 253 reaches the fourth bank contact connected to #3 conductor or conductor 121 which represents the first'digit of the code number of the operated substation A. During this interval as the wipers are rotated one step at a time across the bank contacts, relay 215 operates in 'synchronism and sends an impulse of current over the trunk line to the telegraph office to operate the printing recorder three times.

When wiper 253 reaches the bank contact to which the #3 conductor or conductor 121 is connected, a circuit is completed extending from ground at armature 219 and its front contact, armature 226 and its front contact wiper 253, fourth'bank contact to which conductor #3 is connected over first digit code conductor 121, front contact and armature 120, back over conductor 128, front contact and armature 228,thr0ugh the winding of slow-to-release relay 230, to battery. Relay 230 after an interval energizes and at armatures 231 and 232 disconnects the stepping magnet 240 from under control of the slowoperating relays 205, 210 and 215, and over front contacts and

armatures

233 and 234 com letes a locking circuit for itself indepen ent of its original energizing circuit, from ground at the bank contact upon which wi er 251 is now resting. A branch of the loc ing circuit for relay 230 extends from the ground at bank contacts of wiper 251, through

armatures

233 and 234 to the back contact of armature 241 and the winding of stepping magnet 240, to battery. Each time the stepping magnet 240 is energized it interru t-s its own circuit at its armature 241, there y operating'in the manner of a buzzer to rotate the wipers of the code sender. As a further result of the energization of slowrelease relay 230 it completes a shunting circuit extendlng around one side of relay 220, from grounded front contact and armature 235, armature 229 and its front contact, through one sideof the winding of relay 220, thereby shunting out this relay, which upon. falling away opens the circuit at its armature 222 extending to the printing recorder PR at the telegraph oflice and at armature 221 it opens its locking circuit.

With relay 230 energized the stepping magnet 240 continues to operate in the manner same time wiper 251 has reached bank con- I tact 255 which is connected to the conductor extending to back contact of armature 219 of relay 225 which is still energized'at this time. Consequently, slow-release relay 230 and the stepping magnet 240 are no longer energized as they were over the grounded bank contacts over. which wiper 251 has been rotated. After a short interval when relay 230 is completely deenergized it again closes the slow stepping circu1t for the stepping magnet 240, at armatures 231 and 232, to place it under control-of the slow-operating relays 205, 210 and 215. At grounded front contact and armature 235 the shunting circuit for relay 220 is opened and this relay is again energized from battery through its winding, front contact and armature 227, bank contact 260 upon which wiper 253 is now resting, front contact and armature 226, to ground at armature 219 and its front contact. At armature 221 the locking circuit for relay 220 is completed when it energizes, and at armature 222 the circuit for the printing recording magnet PR is again closed each time relay 215 energizes. Accordingly, the second digit of the code number is now transmitted to the telegraph office.

The stepping magnet 240 continues to rotate the wipers 250 to 252, inclusive, over their associated bank contacts under control of the inter-action of relays 205, 210 and 215 until wiper 253 encounters the bank contact to which conductor #8 is connected. When this occurs the circuit for slow-release relay 230 is again completed over a circuit extendin from battery through the winding of thls relay, armature 228 and its front contact, conductor 128, armature 119 and its front contact, conductor 122, conductor #8 upon which wiper 253 is now resting, front contact and armature226, to ground on armature 219 and its front contact. Relay 230 after an interval energizes and at armatures 231 and 232 and their back contacts removes the control of the stepping magnet 240from the inter-action of relays 205, 210 and 215. At front contact and

armatures

233 and 234 relay 230 completes the locking circuit for itself by way of wiper 251 and the grounded bank contact upon which it is now resting. At grounded front contact and armature 235 relay 220 is again shunted so as to discon nect the trunk line extending to the telegraph office and prevent the transmission of further impulses. A branch of the locking circuit of relay 230 again extends through the winding of the stepping magnet 240, to battery, and the stepping magnet thereby is energized and deenergized each time wiper .It may be stated at thistime that relay 230 has been made slow-to-release for the purpose of preventing it from deenergizingv as the wiper 251 steps between the grounded bank contacts.

The wipers 250 to 253, inclusive, of the code sender OS are therebyrapidly rotated over their bank contacts until wiper 251 reaches its last bank contact 256, and as there is no ground potential upon thisbank contact the slow-release relay 230 is no longer maintained energized and, likewise, the stepping magnet 240 has its circuit interrupted. At

armaturcs 231 and 232 relay 230 upon falling away places the step ing magnet 240 again under control of the inter-acting slow relay s 205, 210 and 215, and at armatures' 233 and 234 a further point in the circuit ofthisrelay and the stepping magnet is opened, at armature 235 the shunt circuit around relay 220 is disconnected and the relay 220 becomes energized immediately upon'the wiper 252 being stepped onto its bank contact 258. The circuit for relay 220 now extends from battery through the resistance, the winding of the relay, front contact and armature 227, back contact258, wiper 252 which is now resting on this bank contact, front contact and armature 226, to ground on front. contact and armature 219. At armature 221 the locking circuit for relay 220 is again completed, while at armature 222 the circuit extending to the telegraph office printer is coin- .pleted when relay 215 energizes. The'stepping magnet 240 continues to advance the wipers of the code sender CS under control of inter-acting relays 250, 210 and 215.

At this time it will be noted that whereas the wipers 250 and 252 will be rotating over the bank contacts, the

other wipers

251 and 253 will be rotating in an arc'away from vthe bank contacts, so that they will not be effective. The printing recorder PR at the telegraph office is operated once each time the stepping magnet 240 advances its wipers one step, and this action continues until wiper 252 encounters the fifth bank contact to which conductor #4 is connected, whereupon, the circuit for slow-release relay 230 is again completed over conductor 128, ar-

mature 118 and its front contact, conductor 123, and the wiper 252 and the bank contact upon which it is now resting. Relay 230 again places the stepping magnet 240 under control of the series of grounded bank contacts over which wiper 250 is now rotating and it also completes its own locking circuit at armature 233, while at armature 235 it again shunts relay 220 so that further im pulses will not be sent to the telegraph oflice. At armatures 231 and 232 the inter-action relays are disconnected from control of the stepping magnet 240 which operates in a buzzer-like action and continues to advance the wipers of the code sender until wiper 250 encounters bank contact 254,. and as this bank contact is no longer grounded the relay 230 and the stepping magnet 240 will no longer be energized. Relay 230 upon falling away slowly, replaces the control of the stepping magnet back again to relays 205, 210 and 215 and their inter-action operation.

The shunt circuit forrelay 220 is removed at armature 235 and it again becomes energized and locks up in order to prepare the trans-- mission of further impulses to the telegraph vided so that the code may be sent any numu ber of times.

The operation of'the code" cut-off switch CO will now be pointed out in detail. As soon as the wiper 252 of the code switch CS,

engages bank contact 257 it completes a circuit extending from grounded armature 219 and its front contact, armature 226 and its front contact, wiper 252 and bank contact 257 upon which it is now restin conductor 143, through the winding of t e stepping magnet 160 to battery,,of the cut-off switch CO. As soon as wiper 252 steps off of bank contact'257 the circuit for stepping magnet 160 is opened and consequently, it retracts its armature and advances the wipers 162 and 163 forward one step onto their first set of bank contacts. -As soon as wipers 250 and 252 step off of their last

bank contact wipers

251 and 253 will engage their first ban-k contacts, the wiper 253 coming to rest upon bank 11% contact 259. The code sender switch CS is now again in the same position it was at the time that its operation was initiated.

In the same manner as has been heretofore pointed out the code number 384 is again transmitted over the trunk line extending to the telegraph ofiice to operate the printing recorder PR and again print the number of the code of the substation A. In a similar manner all of the relays for controlling the code switch CS are operated, as has been pointed out. After the code number has been transmitted the second time the wiper 252 again engages its bank contact 257, so that the stepping magnet 160 of the cut-off switch CO is energized the second time to rotate the wipers 162 and 163 onto their second bank contacts.

Referring again to the cut-off switch CO it will be noted that the wiper 162 requires three or four times. Each time the wipers of the code sender CS make one complete revolution over their bank contacts in transmitting a complete code number, the .cut-ofl switch G0 has its stepping magnet 160 energized once so that for each operation of the code sender the cut-off switch CO will operate one step. 7

With the wiper 162 of the cut-off switch CO resting on its bank contact 164 a circult is completed from ground over the wiper and the bank contact, through the winding of relay-155, to battery. At armature 156 it prepares a locking circuit for itself and at armature 157 and its front contact it extends ground from this armature through the re sistance 153, winding of slow-release relay 150, multiply connected bank contacts upon the fourth. one of which wiper 163 is now resting, back contact and armature 161, and

through the winding of the stepping magnet 160, to battery. Due to the inclusion of the resistance 153 in this circuit the stepping magnet 160 does not energize. However, the slow-release relay 150 energizes and at its armature and front contact 152 it short-circuits the resistance 153. At its grounded front contact and armature 151 relay 150 completes the locking circuit for relay 155 so that it will remain held up after wiper 162 is stepped off of bank contact 164. Stepping magnet 160 is now operated in a circuit including only the relay 150 and not the resistance 153 and it operates in the manner of a buzzer by interrupting its own circuit at its armature 161. It continues to rotate the wipers 161 and 163 in a forward direction over the multiply. connected bank contacts until bank contact 165 is reached, whereupon the circuit for the stepping magnet 160 and slow-release relay 150 is permanently opened and the switch is now in its normal position.

As a further result of the energization of relay 155 it connects ground from its front contact and armature 158, over conductor 129,-

armature 116 and its front contact, through the winding of relay 110, to battery. Relay 110 upon energizing closes a locking circuit for itself from armature 107 over its armature 112, and at armature 111 and its back contact opens a point in the chain circuit 132 extending between the station relay groups SR. At armature 113 and its back contact relay 110 opens the locki circuit .1501 relay 105 extending over armat e 108 and this

redigit conductors

121, 122 and 123 is disconnected. Relay 105 which was released due to the opening of its locking circuit at armature 113 restores the chain circuit over con-' du'ctor 132 and its armature 106 so that any other station relay group, such as SR6, which may have a code stored in the group of relays may seize the code sender OS to operate it and tignsmit the associated code to the telegraph o co.

As a further result of the release of relay 110 and the opening of its armature 113 from its back contact, relay 140 is restored to normal and at its armature 141 and back contact again restores the battery to the multiple conductor 130 so that-any other relays, such as 115, or other station relay groups may seize the code sender equipment. Relay 140 upon releasing opens the circuit of relay 145 at its armature 141, and relay 145 upon releasing in turn opens its armature 146 from grounded front contact, thereby interrupting the circuit for relay 225 which extended over conductor 142. Relay 225 upon restoring opens the armature 219 from its front contact thereby disconnecting the ground circuit from the slow inter-acting relays 205, 210 and controlling relay 215. At armature 227 the initial energizing circuit of relay 220 is opened, while at armature 228 the energizing circuit for relay 230 is likewise interrupted. The code sender switch wipers are now in their normal position as are also the group of relays which control them. The cut-ofi switch G0 has likewise been restored to normal as well as all of the relays which control it and also the station relay roup SR1.

The code sender C is now in position to transmit another code which may be sent in by any other subscriber. The code number 384 which is individual to the substation A has been printed four times upon the tape at the telegraph oflice by the printing recording relay PR and an attendant at the telegraph oflice upon noting the code number will dispatch a messenger to the premises of the subscriber, who may receive a telegram message which is to be transmitted from the telegraph office or perform some other messenger duty.

From the foregoing detailed description of the operation it will be appreciated that only one code at a time may be transmitted by the code sender CS to the telegraph ofiice, but should more than one subscriber in the system dial the number to seize its associated relay group, such as RG, the equipment will operate to engage with the associated station relay group SR and store the code in the group of relays, and immediately upon the transmission of this code the next preceding fice'the code would be mutilated or an incor-- rect code would be transmitted. In order to take care of this the code sender switch CS is arrange-d to automatically restore its wipers to their normal positions whenever they are accidently stepped off of the first step of the bank contact which is their normal position. When this occurs and wiper 251 is moved onto its second bank contact, ground is extended from this bank contact over the wiper, back contact and armature 228, through the winding of slow-release. relay 230, to battery. Relay 230 upon energizing completes a locking circuit for itself at armature 233 in series with armature 234. A branch of the holding circuit'of relay 230 extends by way of armature 241, through the winding of the stepping-magnet 240, to battery. The stepping magnet 240, therefore, operates, in the manner of a buzzer by interrupting its own circuit at its armature 241 and rapidly rotates the wipers 250 to 253, 1nclusive, of the code sender CS in a forward direction over their associated bank contacts. When wiper 251 reaches bank contact 225-instead of picking up direct ground from the associated bank contact it completes a circuit through the conductor extending to the back contact and armature 219 and ground, and the rotary action continues.- Upon wiper 251 stepping oil of bank contact 256 wiper 250 will engage the first bank contact which is grounded and the stepping magnet 240 continues to be alternately energized and deenergized, stepping the wiper 250 and the other wipers across their bank contacts until wiper 250 steps ofl of the last bank contact in the arc, in which position the code sending switch GS is at normal, whereupon the circuit for the stepping magnet 240 and likewise the slow-release relay 230 is interrupted and relay 230 upon restoring its armature opens a further point in the circuit of the stepping mag net 240. The switch has now reached its normal position ready to receive a code numcode slgnalling equipment to transmlt a code her and transmit it to the telegraph oifice.

As the example illustrated and described comprises only a three digit system it will be appreciated that this may be changed to a large one by merely including additional selectors such as S, or it may be reduced if desired. Similarly the code signalling equipvment may be arranged to transmit more or less than the number of digits indicated. For these reasons it is not desired to limit the invention to the exact embodiment as has been described, but only to the extent of the appended claims,

What is claimed is:

1. In a combined telephone and signalling system, a central exchange, subscribers lines connected to said exchange, means atsaid exchan e controlled by a calling subscriberfor esta lishing a telephone connection with any other subscribers line, code signalling equipment at said exchange, code relays at the exchange individual to each subscribers line, means controlled by a calling subscriber for operating the associated code relays to start the operation of said signalling equipment, a recording ofiice connected to said exchange, and means controlled by said signalling equipment to transmit a code characteristic of said callin subscriber over the connection to said recor ing ofiice.

2. In a combined telephone and signalling system, a central exchange having automatic switches over which telephone connections are established between subscribers lines under control of acalling subscriber, code signalling equipment at said exchange, means controlled by a calling subscriber for establishing a connection over said automatic switches with said signalling equipment, means individual to each of said subscribers lines for controlling said signalling equipment to generate a code characteristic of said calling subscriber, a telegraph ofiice connected to said signalling equipment, and means controlled by said signalling equipment for transmitting said code a plurality of times to said telegraph oflice.

3. In a combined telephone and signalling system, subscribers lines extending to an exchange having automatic switches over which the subscribers control the establishment of telephone connections, code signalling equipment at said exchange, codegenerating means individual to each subscribers line, booster battery means accessible to said automatic switches, means controlled over any subscribers line for establishing a signalling connection over said switches with said booster battery means, means responsive to said connection for extending said booster battery means back over said automatic switches to operate said code generating means individual to the calling line, and means responsive to the operation of said code generating means for controlling said characteristic of said calling line.

4. In a combined telephone and signalling system, an exchange having automatic switches controlled by calling subscribers for establishing telephonic connections with called subscribers, code signalling equipment in said exchange, code generating means individual to each subscribers line, booster .battery means accessible to said subscribers lines, means controlled by a calling subscriber for controlling said automatic switches to establish a connection with said in line a plurality of times to said telegraph o ce.

5. In a combined telephone and signalling system, an exchange having automatic switches over which subscribers control the establishment of telephone connections, a holding relay accessible'to said automatlc switches, a relay group "individual to each subscriber for initiating a code characteristic of said subscriber, code signalling equipment controlled by said individual relay groups, means responsive to the same control of said switches by any of saidsubscrlbers for operating said holding relay, and means responsive to theoperation of said holding relay to control said relay group and. operate said code signalling equipment only in accordance with the code of the calling subscriber. A

6. In a signalling system, a'plurality of lines each identified by a certain code des gnation, a plurality of control means, a series of selecting switches controlled by a hne to select an idle one of said control means, code registering equipment, means responsive to the selection of one of said control means by a line for operating said registering equip ment over said selecting switches to register the code designation of the line, and means for preventing the registration of the code of any other line while the code of the first line is being registered by said registering equipment.

7. In a combined telephone and signalling system, a central oifice, a plurality of telephone stations each connected to said central oflice, automatic switches at said ofiiee, means controlled from any telephone station for operating said automatic switches to establish a telephonic connection with any other telephone station, relay means accessible to said switches, a relay group individual to each of said telephone stations for generating a code designation characteristic of the station, a signal transmitter at said central ofiice controlled by said relay groups, means controlled from any telephone station for operating said automatic switches to select said relay means and operate the same, means responsive to the operation of said relay means for operating the relay group individual to the telephone station over a circuit connection extending back over said automatic switches, and means responsive to the operation of said individual relay group for operating said signal transmitter to transmit a code designation characteristic of the telephone station.

8. In'a combined telephone and signalling system, a central oflice, a plurality of telephone stations each connected to said ofiice,

automatic switches in said office, relay means at said oflice, means controlled from any of said telephone stations for operating said automatic switches toestablish a telephonic connectionwith any other telephone'station or a signal connection with said relay means, a relay group individual to each of said telephone stations 'for generating a code characteristic of the associated station, signal transmitting means at said central oflice, means responsive to the connection of said telephone station with said relay means for operating the same to give an indication to said telephone station of such connection and forat the same time operating the relay group individual to the telephone station, and means responsive to the operation of said relay group for operating said signal transmitting means to transmit a signal characteristic of said telephone station.

9. In a telephone and signalling system, a central oflice, telephone substations each connected to said oflice, automatic switches in said office, means controlled from any of said substations for operating said automatic switches to connect with any other of said substations, signal initiating means common to said substations, code generating means individual to each of said substations for generating a code designation characteristic of the associated substation, signal transmission means connected to said code generating means, means controlled in the same manner from any of said stations for operating said automatic switches to connect with said common signal initiating means to operate the same, means responsive to the operation of said signal initiating means for operating said code generating means over a connection extending back over said automatic switches, and means responsive to the operation of said code generating means for controlling ,said signal transmission means to transmit the code designation of the calling telephone substation.

10. In a telephone and signalling system. a central oflice, telephone substations each connected to said office, automatic switches in said ofiice, means controlled from any of said substations for operating said automatic switches to connect with any other of said substations, signal initiating means common to said substations, code generating means individual to each of said substations for generating a code designation characteristic of the associated substation, signal transmission means connected to said code generating means, means controlled from any of said stations for operating said automatic switches to connect with said common signal initiating to the operation of said signal initiating ment in said exchange, means control means for operating said code generating means, and means responsive to the operatlon of said code generating means for controlling said signal transmisslonmeans to transmit the code designation ofthe calling telephone substation. v

11. In a telephone and signalling system, a central oflice, a pluralityof telephone substations connected to said ofiice, automatic switches in said oifice, means controlled-from any-of said-substations for operating said automatic switches to establish a telephone connection with any other of said substatlons,

signal initiating means common tosaid substations, signallin equipment in said ofiice for transmitting signals of a calling substation, means controlled in a similar manner by any of said substations for operating said automatic switches to establish a connection with said signal initiating means to operate the same, means responsive to the operation of said signal initiating means for operating said signallin equipment over a connection extending bac over said automatic switches, and means responsive to the operation of said signalling equipment for transmitting a code designation characteristic of the calling substation.

,12. In acombined telephone and signalling system, a central exchange having substaion lines extending thereto and terminating in automatic switches, code signalling e uiped rom any substation for operating the automatic switches to establish a telephone connection with any other substation or for'connecting with said code equipment, means in said code equipment responsive to the connection of a substation line therewith for generating a code indicative of the substation, and means 1 for transmitting said code 'over a different connection from said exchange.

13. In a combined signalling and telephone system, a central exchange having substation lines extending thereto and terminating in automatic switches, code signalling equipment in said exchange, means controlled from any substation in accordance with the number of any other desired substation for operating the automatic switches to establish a telephone connection therewith, means controlled from any substation in accordance with a number common to all of said substations for establishing a connection over said automatic switches with said signalling equipment, means in said equipment respon sive to the connection of any substation therewith for generating a code individual to only said substation, and means for transmitting said individual code from said exchange.

14. In a combined telephone and signalling system, a central exchange having substation lines extending thereto and terminating ;ment in said central exchange, means controlled at a calling substation for operating the automatic switches in accordance with the number of a called substation to establish a telephonic connection therewith, said means operative to control the automatic switches in accordance withanumber common to all of said substations to establish a connection with said signalling equipment, means in said signallin equi' ment responsive to the connection 0 a su station therewith for generating a code number individual only to that substation, and means operative to transmit said code number from said exchange regardless of whether the calling substation has been released from its connection with the signalling equipment, v 15. In a combined telephone and signalling system, acentral exchange having substations connected thereto, code signalling equipment in said exchange, means in said exchange controlled by a calling substation for establishing a telephonic connection with any desired called substation, said means controlled in the same manner by any calling substation for establishing a connection with said signalling' equipment, means for indicating to the substation when such signalling connection is established whereby the connection may be rel-eased immediately, means in said signalling equipment for generating a code corresponding to the calling substation upon the connection therewith, and means for then transmitting said code independently of the continued connection of the calling substation with said equipment.

16. In a telephone system in which a signalling'systein is incorporated, a central exchange, substations connected to said exchangeand each having an impulse sender thereat, code signalling equipment at said exchange, means responsive to the operation of the impulse sender at a calling substation in accordance with the designation of a called substation for establishing a telephone connection therewith, means responsive to the operation of the impulse sender at a calling station in accordance with a designation common to all of said substations for establishing a connection with said signalling equipment, means in said signalling equipment responsive to the connection of a substation therewith for generating a code individual only to that substation, means for indicating to the connected-substation that the connection with the signalling equipment is established so that the connection may be released if desired, and means in said signalling equipment for transmitting the code of the calling substation from said central exchange.

17 In the combination of a telephone system and a signalling system, a central exchange, substation lines extending to said in automatic switches, code signalling equip-- exchange, a series of automatic switches in said exchange controllable by said substation to establish telephone connections between them, code signalling equipment in said exchange, means for controlling the automatic switches in the same manner by all of the substations for establishing a connection with said signalling equipment, a circuit connection extendin from the connected substation line to said 0 ment exclusive of said automatic switches, and means in said signalling equipment controlled over said circuit connection for initiating the generation ofa code individual only to the connected substation.

18. In the combination of a telephone system and a signalling system, a central exchange, substation lines terminating in said exchan e, automatic switches controlled by any cal ing substation for establishing a telephone connection with any called substation, code signalling equipment in said exchange, a circuit connection extendin from the terminating end of each substatlon line to said signalling equipment, means for controlling the automatic switches in the same manner by any calling substationto extend a connection to said signalling equipment, means responsive to said connection for energizing said circuit connect-ion from the terminating end of the substation to initiate the eneration of a code by said signalling equipment which is individual only to the connected substation, and means in said signalling equipment for transmitting said code.

In witness whereof, I hereunto subscribe my name this 2d day of July, A. D. 1930.

EDWARD S. PETERSON.

ode signalling equip-