US2052018A

US2052018A - Signaling system

Info

Publication number: US2052018A
Application number: US745687A
Authority: US
Inventors: Harry E Hershey
Original assignee: Associated Electric Laboratories Inc
Current assignee: Associated Electric Laboratories Inc
Priority date: 1934-09-27
Filing date: 1934-09-27
Publication date: 1936-08-25
Anticipated expiration: 1953-08-25

Description

Aug. 25, 1936.

' SENDING STATION H. E. HERSHEY SIGNALING SYSTEM Filed Sept. 27, V1934:

4 Sheets-Sheet 1 HARRY E. HERSHEY BY /Z li l' ATTORNEY.

Aug. 25, 1936.

H.' E. HERSHEY SIGNALING lSYSTEM Filed sept. 27 1954 STATION "A" FIRST STATION B INTERMEDIATE 4 Sheets-Shed'I 2 FIG. 6

INVENTOR.

HARRY E. HERSHEY ATTORNEY.

Aug. 25, 1936. f' H, E YHERSHEY 2,052,018

-SIGNALING SYSTEM Filed Sept. 27, 1934 4 Sheets-Sheet 5 FIRST DIGIT Tm Tm m Reels-VER SENDER mfr (PZ-34) (l-S HARRY E. HERSHEY BY www ATTORNEY.

Aug. 25, 1936. E HERSHEY f 2,052,018

SIGNALING SYSTEM lFiled Sept. 27, 1934 4 Sheets-Sheet 4 LAST DIGIT REGISTER SENDER Il. o N Lf) ll l Tn Q' n f- 7 INVENTOR.

HARRY E. HERSHEY ATTORNEY.

Patented Aug. 25, 1936 PATENT orrics SIGNALING SYSTEM Harry E. Hershey, Chicago, Ill., assignor to Associated Electric Laboratories, Inc., Chicago, Ill., a corporation of Delaware Application September V2'7, 1934, Serial No. 745,687

3 Claims.

This invention relates in general to signaling systems butmoreparticularly to a system in which a sending station transmits information to a plurality of receiving stations, and the prin-l cipal object is to provide a new and improved transmitting and receiving system suitable for use in disseminating information concerning the' arrival of railroad trains and such or any other condition .requiring the transmission of signals to` l0 :a'number of diiierent locations.

A further object is to provide a high speed system for quickly transmitting the digits of a number and displaying the digits almost simultaneously at the receiving stations.

A further object of the invention is to provide only a single key set for setting up the digits of the number to be transmitted.

A particular feature of the invention resides in the circuit arrangement whereby a single key 2o set is provided together with a register for each digit, the digits being automatically transmitted to the registers in sequence as they are set up on the keys. AAnother feature is directed to the means whereby the same indicators for each digit at the receiving stations arel operated inv sequence so that the operation of the indicators at the sending station serve as a check back. A11 additional feature concerns the means for indicating at the sending station that the indica- V tors at all the receiving stations are in Vnormal condition.

The above object and features together With others not speciiically pointed out will be described later in detail in conjunction with the accompanying drawings which show by means of the usual schematic circuit diagrams a preferred embodiment of the invention. In the drawings- Fig. 1 shows the key set, indicators and other equipment at the sending station;

l Fig. 2 shows several receiving stations together with their digit indicators;

Fig. 3 showsthe circuit of the first digit reg ister and sender; Y

Fig. 4 shows the circuit of the last digit regla ister and sender of the system; v Y

Fig. 5 illustrates diagrammatically one of the indicator devices; while" Fig. 6 is a front View of an indicator with one y of the digitsin exposed position.

'00 Referring now more specifically to Fig. 1, la

sending station is provided with a row of keys numbered l to 0. These keys are of the nonlockingtype. In addition a combination error and release key is provided. The sending station is likewise provided with a checking receiver which comprises a number 'of digit indicators one for each digit of a number which may be transmitted. These may be arranged in a suitable panel with the first digit indicator on the top and the last digit indicator on the bottom. 5 Adjacent each indicator is a pilot light which indicates when itsi associated indicator is at normal.

In Fig, 2a number of receiving stations are Shown, connected in serial relationship, station l0 A being theirst one in the chain, station Bthe v second or intermediate one, while station Cis the lasty station in the chain. Each receiving' station is provided with a digit indicator for each digit of the number to be received. All of the indicators 15 at a particular receiving station are arranged `in a panel in suitable manner so as to be easily visible. Although onlythree receiving stations A, B and C are shown, it will be understood that any number of intermediate stations similar to 20 station B may be connected in serial relation with the `other stations, the number of receiving stations being practically unlimited lIt willalso be understood that while an indicator at each off the receiving stations is shown for the iirstl digit, 25 an intermediate digit, and the last digit, any number of additional indicators maybe used depending on the number of digits in the number which is to be received.

At this point it may be-desirable torfirst vde-V 30- scribe the general structure and operation of yone of the indicating devices or indicators as shown in Figs. 5 and 6. It comprises essentially a rotating cylindrical ,disc 43 having printed on its surface the numerals 1 to 0 together with a blank 35, space, all evenly spaced around the circumference of therdisc 43. Disc 43 is pivoted on a shaft 45 together with a ratchet wheel 59. A double acting pawl 58 Vis pivoted at 5l and so arranged on opposite sides of the -ratchet wheel 53 thatv when 40 the magnet l energizes the cylinder 43 is rotated one half a step and when the magnet deenergizes the other half step rotated the cylinder 43 to a position where a numeral, such as indicated at Fig. 6, isl visible through the opening of 4.5 the face plate 44. The energization and deenergization of the magnet each time'engaged the pawl 58 with oneof the teeth of the ratchet wheel 59 to rotate the cylinder 43 half a step. A 'coil spring at the armature end of the double acting 50 pawl 58 restores the pawl to normal position when the magnet 60 deenergizes and rotates the disc 43 one-half a step. At each energization the magnet 6B likewise closes its contacts 6l. Mounted nxediy on the same shaft 45 of the disc or 55 cylinder 43 is a cam 62, which has a projection 56 on its outer periphery, so that in the normal stopped position of the cam 62 this projection 56 engages the contact springs 63 to hold them in closed position, while during the rotation of the cam the contact springs will be opened. In the operation of the indicator, for each two steps of the rotation of the cylinder 43 a numeral or digit is exposed in the face plate 44 and in the normal or starting position a blank space is ex posed in front of the opening. As the cylinder 43 is rotated the numerals 1 to 0 will be positioned in the openings of the face plate 44 in consecutive order.

Referring to Fig. 3, a group of relays |00 to |30, inclusive, are shown which constitute the registers for the first digit of the number to be transmitted, together with the sender switch S comprising a rotary switch of the well known type having a wiper |50 which is rotated in a forward direction over its bank contacts under control of the stepping magnet |35. The bank contacts of the switch S are connected to contact springs controlled by the register relays ||0 to |30, inclusive. The objects of this sender is to register the first digit of a number set up by the key set and mark the bank contacts of the switch S so that during rotation of the wiper |50 impulses are transmitted to set the indicators at the receiving stations. In Fig. 4 the last digit register and sender is shown and this is identical with the equipment of Fig. 3, it being understood also that any number of intermediate digit registers and senders may be connected between these two, depending on the number of the digits in the number to be transmitted to the receiving stations.

The apparatus as shown in the drawings is in its normal position ready to be operated to transmit a number containing a plurality of digits to each one of the receiving stations. Under these conditions relay |45, Fig. 3, of the rst digit sender, relay 245, Fig. 4, of the last digit sender, as well as the corresponding relays in the intermediate digit senders are all normally energized. The energizing circuit for relay |45 extends from battery through the winding of relay |45, conductor 36, through Figs. l and 2, normally closed off normal contact 83 of the rst digit indicator at station A, which is the first station in the series of stations, off normal contact '|3 of intermediate station B, and then through all other intermediate stations which may be in the system, then through olf normal contacts 63 of the station C, which is the last station in the series; over conductor 3| through the off normal contacts |3 of the rst digit indicator at the sending station to ground. The foregoing series chain circuit through all of the rst digit indicators at each of the receiving stations as Well as at the sending station maintains relay |45 normally energized. At its front contact and armature |46 this relay extends groundY over conductor 39 through the pilot lamp 'I to battery. The pilot lamp which is associated with the first digit indicator at the sending station, by its illumination indicates to the operator at the sending station the fact that all of the first digit indicators at the receiving stations are in their normal or home position. At its front contact and armature |41 relay |45 extends ground over conductor 39 in series with all similar normally closed contacts on the intermediate register senders whose relays similar to relay |45 are energized, then through armature 248 and the normally closed front contact of relay 245 of the last register sender, and completing the circuit over conductor 40 through Fig. 3 and Fig. 1 through the winding of relay 25 to battery.

This chain circuit energizes relay 25 and disconnects the ground potential from its armature and back contact 26 for a purpose which will be later on described.

The relay 245 of the last register sender is energized in a similar manner as relay |45 of the rst register sender, over a circuit extending over conductor 35 through Figs. 3, 1 and 2, the off normal contacts 69, 79, 69 and I9 of the last digit indicators at each of the receiving stations to ground at the last digit indicator of the sending station. At its armature 246 relay 245 connects ground to conductor 4| to illuminate the pilot lamp |'l of the last digit indicator.

It Will be understood that the intermediate register senders, not shown, will have relays similar to relay |45 of the rst register sender, energized through a chain of off normal contacts at each of the receiving stations and the sending station, so that the associated digit pilot lamp will be illuminated. The illumination of all the pilot lamps at the sending station indicate that the indicators are all in normal position.

In describing the operation of the system it will be assumed that the apparatus is used in a railroad station for indicating at the gate entrances to the train shed the time of arrival or departure of a train. Under these conditions, it will be assumed that the sending station is located at an interlocking tower at the entrance of a train shed where the operator will control the distribution of the incoming trains to the various tracks. Accordingly, the station A would be located in the waiting room of the railroad station for example, Where the patrons would be Watching for the arrival of incoming trains. Station B and the intermediate stations Would correspond to the baggage room, pay-masters department, and mailing department, While the station C would be located in the train shed. The operator in the tower noting the time of arrival of the train would transmit this information to the various enumerated stations.

Assume now that the operator in the tower at the entrance to the train shed notes the approach of a particular train, say at 4:58 oclock. He therefore rapidly and in succession operates the

keys

4, 5 and 8 of his key set. The depression of key 4 closes a circuit extending from ground on armature 22 and. its back contact, common conductor 50, lower set of contact springs of operated key 4, conductor 55, armature |03 and its back contact, through the winding of relay ||0 to battery. At its front contact and armature relay ||0 upon energizing completes a locking circuit for itself extending through the Winding of relay |05 to the grounded conductor 50. Relay ||0 therefore remains energized although the key 4 is released. As a further result of the depression of key 4 ground from grounded conductor 50 is extended through the upper set of contacts of key 4 to conductor 5|, armature |06 and its back contact, through the Winding of relay |30 to battery. Relay |30, upon energizing, closes a locking circuit for itself at its armature |3| through winding of relay |05 to grounded conductor 50. At its front contact and grounded armature |08 relay |05 completes the circuit of relay |00 to battery. Relay |05 also closes its 75- conductor 58.

Cit

'I'he operation of the key 5 places ground from the common conductor 58 through the key contacts to conductors 53 and 54 which extend by way of armatures of relays |88 and |85 to conductors 53 and 54 to the second register sender. The operation of the relays in the second register sender which correspond to relays |88 and |83 of the first register sender, transfers the conductors 5|' to 55 direct to the same conductors extending to the intermediatesenders in case additional digits would be transmitted or as shown to the last register sender, Fig. 3. The depression' of key 8 connects ground from common conductor 58 to

conductors

52 and 53 which conductors are now extending through the rst, second, and inu termediate register senders to

conductors

52 and 53 to the last register sender; conductor 52' extending by way of armature 281 and its back contact, through the winding of relay 225 to battery; This relay, upon closing its locking armature 226 completes a locking circuit for itself through the winding of relay 285 to grounded Conductor 53 extends by way of armature 28| and its back contact through the winding of relay 228 to battery. This relay, upon energizing, completes a locking circuit for itselfY at its armature 22| through relay`285 to grounded conductor 58. The operation of relay 205 completes a circuit for relay 288 at its grounded front contact and armature 298. Relay V288 opens armatures 28|, 282 and 283 from their bank contacts, and relay 285, armatures 285 and 281. As this digit sender is the last one in the chain these relays Will not further extend the conductors 5|V to 55', inclusive.

Returning now to the energization of relay ||8, Fig. 3, at its back contacts and armatures ||2, ||3, ||4 and ||1, it removes ground from

bank contacts

1, 2, 3 and 4 or the switch S to which these armatures are connected. Relay |38 removes ground from its armatures |32, |33, Yi34 and |31 to remove this potential from the bank contacts 4, 7, 9 and 0 in the bank of the switch. It will be seen that bank contact 4` has ground removed from both armatures ||1 and |32, while some of the remaining bank contacts while disconnected from ground by one arvmature lare, however, connected to ground at an armatureof an unoperated relay.

The intermediate register sender forthe digit 5 performs the same action but at differentV bank contacts of its sender switch S. Inthe last register sender, relay 228 by operating armatures 222', 223, 224 and 2|9 removes ground from

bank contacts

2, 5, 8 and 9, while relay 225 at'armatures 221, 228, 229 and 232 disconnects ground from

bank contacts

3, 6, 8 and 10. Bank contact 8 therefore has ground remov'edfrom both armatures 224 and 228. n

All of the switches S at each of the register senders are now in position to transmit the impulses for operating the digit indicators'ateach of the receiving stations as well as at theV sending station. Referring again to Fig. 3, as a further result of the energization of relay ,|88 ground is connected to its front contact and armature |04 over conductorV |5|, normal or home position Contact |52 in the bank of the sender S, wiper |58, bank contact and armature |4I, through the winding of thestepping. magnet |35 to battery. The magnet |35 energizesA and retracts its pawl preparatoryto stepping the wiper |58 when the magnet Vdeenergizes. At its front contact and armature |36 Vitrconnects ground to conductor 31 by way of: Figs. 1 and2 through the resistance 82 and the winding ofthe first digit indicator 88 toy battery, .at the station A., The resistance 82 in series with the Winding of the indicator B8 isffor the purpose of reducing the current flow. The energization of the magnet 88 of the rst digit indicator operatesvthe pawl158 shown in Figi 5 and rotatesthe drum 43 one-half a step. At its front'contact and armature 8| ground is extended by the indicator 88 to the next or intermediate station B through resistance 14, the winding of the indicator magnet 18 to battery. This indicator in turn operates its armature and at its front-,contact and armature 1| closes the circuit to the intermediate stations and these in turn complete theL circuit to the indicator 68 at the last station C through resistance |54. The indicators at each one of the receiving stations therefore `energize in sequence from the first to the last station. At the front contact of armature 6 the indicator 68 completes the circuit over conductor 38 through resistance 8, and the winding of the indicator 5 to battery at the sending station. This indicator likewise takes one-half a step. At its front Contact and armature 8 indicator magnet 5 closes a circuit over conductor 38 .through the winding of relay |48, Fig. 3, to battery.

` When. the rst digit indicator 88 at the rst receiving station vA was energized over conductor 31, in addition tooperating its armature contacts `8| and rotating the drum 43 one-half a step, itV also moved the cam 84 out of engagement with the cam contacts 83, thereby permitting them to open. Atrstation B and other intermediate stations cam 12opens contacts 13, at station C which is vthe last station cam 52 opens contacts 63, while at the sending station the cam 8 opens the cam contacts I3. These cam contacts which it willbe recalled complete a `series chain circuit extendingyfrom ground at the cam contacts I3 of thejsending station to maintain relay |45, Fig. 3, of the rst register sender energized normally. The. opening of these cam contacts therefore deenergizes this relay and at its armature |46 it removes ground from conductor 38, extending to the pilot lamp 1 and thereby extinguishes this lamp. This serves as an indication to the operator atthe sending station that the setting up of the first digit on the indicators has begun. At armature |41 relay |45 removes ground from conductor 38 extending in series through all similar relays |45 of the intermediate register senders, finally extending through armature 248 of the lastregister sender, and back over conductor 48 to relay 25 of Fig. l. This relay consequently is deenergized and at its armature 26 prepares a locking circuit for relay 28 for a purpose which will be later on pointed out.

Returning now where relay |48 of the rst register sender is energized by the energization of the rst digit indicator 8 at the sending station, this relay at its armature |4| and its back contact opens thecircuit of stepping magnet |35 which extended through wiper |58 to armature |04 of relay |00. Stepping magnet |35 consequently retracts its armature and rotates wiper |50 in a forward direction onto its first bank contact and olf of its last bank contact |52 which is the home position contact. As a further result of the energization of the stepping magnet |35 it disconnects ground at its armature |36 from conductor |31 extending to the first digit indicator at the first station A. This indicator 80 thereupon deenergizes and at its armature 8| opens the circuit for rst digit indicator 10 of station B. This indicator in turn at its armature 1| opens the circuit for the adjacent intermediate indicators of the intermediate stations and the last of these in turn open the circuit for the first digit indicator 60 at the last station C. The indicator 60, upon deenergizing opens its armature 6| and disconnects ground from conductor 30 to open the circuit of the first digit indicator 5 at the sending station. This indicator 5, upon deenergizing, at its armature 6 disconnects ground from conductor 38 to open the circuit of relay |40. At relay |40 at its armature I4| again prepares a circuit for stepping magnet |35. All of the first digit indicators at each of the receiving stations as well as at the sending station have taken two steps, that is, have been each energized and deenergized once so as to rotate indicator discs 43 two one-half steps or one complete step to replace the numeral or digit l before the opening 44 and render it visible. From the foregoing operations it will be seen that each time the stepping magnet |35 energizes the indicators energize to rotate the drum one-half step and when the indicators at the sending station energizes it closes the circuit to relay |40 which in turn opens the circuit of the stepping magnet |35 to energize it, so that at its armature |36 it opens the circuit of the iirst digit indicator at station A, and this in turn through the chain to the last sending station and its digit indicator, which again opens the circuit of relay |40. This alternate energization and deenergization between relay |40 and stepping magnet |35 and relay |40 continues as long as ground potential is picked up by wiper |50 as it rotates across its bank contacts. For each operation of the stepping magnet |35 and relay |40 or for each step of the wiper |50 each of the rst digit indicators at the stations operate to successively place digit numerals Visible in the opening of the plate 44.

It will be remembered that the rst digit 4 of the number transmitted by the operator by the operation of key 4, locked relays |0 and |30 in energized condition and consequently operated their associated armatures to remove ground potential from the bank contacts of the switch S. The remaining relays of the register set not being energized at this time the bank contacts to which their armatures are connected will have ground potential connected to them. Due to the energization of register relays IIO and |30, however, armatures I|1 and |32 of these relays will disconnect ground from bank contact No. 4, and it is therefore seen that as wiper |50 is stepped from the normal position contact |52 to its first bank contact it will pick up ground from the armature of relay I5 to energize the stepping magnet |35. Likewise bank contact 2 is connected to ground from the armature of relay |20, and contact 3 being connected to the armature which is grounded on relay |25 will each energize the stepping magnet |35. When wiper |50 reaches bank contact No. 4 no ground will be present, and the stepping magnet I35 therefore does not operate so the wiper |50 of switch S cornes to rest. The wiper |50 has accordingly made four steps and the stepping magnet |35 energized and deenergized fourv times. As a result of this circuit arrangement described, all of the first digit indicators at the receiving stations have stepped the drum 43 around to a position where the digit 4 is visible in the opening of the face plate 44 at which position the indicators remain at rest. All of the apparatus of the iirst digit sender in Fig. 3 reinains in the position in which it is set.

The second register sender or other intermediate register senders are operated in a similar manner as described in connection with the rst register sender to step the indicators I0, 60, 10 and 80', shown in part, at the receiving stations to set these indicators in accordance with the second digit of the number transmitted, which is 5. In the last register sender Fig. 4, register

relays

220 and 225 being locked energized, the operation of this last register sender is similar to that described in connection with the first register sender, and the operation will therefore be described only briefly. Ground potential connected to armature 204 by relay 200 extends over conductor 25| to back contact 252, wiper 250, armature 24|, to the stepping magnet 235. Magnet 235, upon energizing, connects ground at armature 235 to conductor 34 through Figs. l and 2, resistance 81, to the magnet of the last digit indicator at the station A. This indicator at its armature 88 closes the circuit to the intermediate station indicator 15 over resistance 11. At armature 16 indicator 15 closes a circuit through the intermediate indicators of the other stations through resistance 61 to indicator 65 of the last station C. Indicator 65 which in turn at its armature 66 completes a circuit over conductor 32 through resistance I0 to indicator I5 at the sending station. The digit indicator |5 at its armature I8 closes a circuit over conductor 42 to energize control relay 240 which in turn at its armature 24| opens the circuit of stepping magnet 235. This magnet then upon deenergizing steps the wiper 250 onto the first bank contact. At armature 236 the stepping magnet 235 interrupts the circuit chain extending through all the last digit indicator magnets so that eventually at armature I6 of the sending station indicator I5 the circuit of relay 240 is again interrupted so that upon the retraction of its armature 24| stepping magnet 235 has its circuit completed over the rst bank contact from ground on the armatures of relays 2I0 and 2I5.

As a further result of the operation of each of the last digit indicator magnets I5, 65, 15 and 85 the associated cams I8, 68, 18 and 88 are rotated and consequently the corresponding cam contacts I9, 69, 19 and 89 are opened. 'I'he opening of these cam contacts opens the circuit extending over the conductor 35 to relay 245 and thereby deenergizes this relay which it will be remembered is normally maintained energized. At its armature 246 relay 245 removes ground from conductor 4| which extended to pilot lamp I1 and thereby extinguishes this lamp to inform the operator at the sending station that the last digit indicators are being operated. At its armature 248 it opens a circuit extending from ground on the first register sender at armature |41 of relay |45 through all the intermediate senders over conductor 40 to relay 25 of Fig. 1. This relay ac- `cordingly restores and closes its armature 26 to ground without effect, however, at this time.

The stepping magnet 235 of the switch S in the last register sender continues to operate the wiper 250 ,across its bank contacts as long as it picks up ground from the contacts. When wiper 250 reaches the eighth bank contact connected to armatures 224 and 229 of operated

relays

220 and 235, ground is no longer present and the switch S comes to rest. Due to the interaction between the stepping magnet 235 and relay 240,

as has been heretofore explained, the indicators of the last digit at each of the receiving stations A, B and C and at the sending station have been operated to rotate the drum 43 to render visible the `numeral or gure 8. Accordingly, the number 4:58 is now presented and rendered visible to each one of the receiving stations and at the sending station, indicating at these positions the time of arrival of a train as noted and set up by the operator in the tower at the entrance of the train shed. The numbers set up on all of the indicators remain in this condition until released by the operator at the sending station.

Briefly summarizing the above operations, it is seen that setting up the digits on the key set causes the digits in the register senders to be stored or registered in rotation, one digit for each register sender. 'I'he sender switch operates immediately to transmit impulses to its associated indicator at all the receiving stations.

The indicators at the sending station serve as a check to the operator that the indicators at all the receiving stations have been operated in a similar manner. The pilot light at the sending station for each digit likewise indicates the normal or operated condition of the equipment, and

`informs the operator when the apparatus is in condition and ready to be operated. The failure of the operation of any of the digitV indicators will prevent the operation of the associated indicator at the sending station and the operator will be aware of the inoperative condition. Incorrect operation of any indicator is likewise reected by the sending station indicator. Each register sender operates independent of the remaining register senders and the transmission of the impulses to their associated indicators occurs practically simultaneously or as fast as the keys of the sending station can be operated. The display of the number including any number of digits will occur practically simultaneously at each of the stations instead of one digit at a time. There is no limit to the number of indicators which may be used at a receiving station or the number of digits which may be received or transmitted. Likewise the number of stations connected in series is not particularly limited. Other stations or indicators can be added as desired.

In order for the operator to restore the indicators and other equipment to normal position, the combination release and error key R is operated. This action connects ground to the contacts of the key R through winding of relay to battery. Relay 20, upon energizing, at its front contact and armature 2| closes a locking circuit for itself independent of key R extending from ground on armature 26 of relay 25, which relay it will be recalled, is now in deenergized position, or whenever any of the indicators are operated. At armature 22 relay 20 removes the common locking ground from conductor 50. In the first register sender, Fig. 3, the conductor 50, no longer having ground potential upon it, perlstepping magnet |35.

mits the relay |05 to deenergize and this relay in turn at its armature |08 restores relay |00. The locking circuit for relays ||0 and relay |30 is likewise opened and these relays restore to normal, and retract their armatures to connect `the ground to the bank contacts of switch S.

The intermediate register sender relays are released 'in a similar manner. Referring now to Fig. 4 of the last register sender, the removal of' ground from common conductor 50 restores relay 205 and this in turn relay 200.

Relays

220 and 225 which were locked energized to conductor 50 now restore and open their locking circuits. 'I'hese two relays restore their armatures and again connect ground which they disconnected i to the bank contacts of the switch S.

At the time relay |00 was deenergized due to the removal of ground from conductor 50, it also restored its armature |04, thereby disconnecting ground from conductor |5| and the bank contact |52 of the switch S. This same action takes place in the corresponding relays in the intermediate register senders, and relay 200 of the last register sender which disconnects ground from bank contact 252 at its armature 204. It will be recalled that wiper |50 of the switch S came to rest on the fourth bank contact to which it was stepped. vConsequently when relays 0 and |30 deenergize ground is again connected to this bank contact from armatures 1 and |32,

thereby completing a circuit for the stepping magnet by way of wiper |50 and contact |4| of relay which had been deenergized after the indicators were set. The stepping magnet |35 closes ground on its armature |36 and extends it over conductor 31 through resistance 84 to the rst digit indicator 80 at the rst station A. This indicato-r at armature 8| closes a circuit for indicator 10 at station B, which in turn at armature closes a circuit for the intermediate or the last indicator 60 at the last station "C, Indicator 60, upon operating, closes armature 6| and connects ground to conductor 30 through resistance 8 to the first digit indicator `5 at the sending station. Indicator 5 at arma- 2? ture 6 in turn connects ground to conductor 38 to complete the circuit of control relay |40; at armature |4| this relay opens the circuit of relay The continuous interaction between stepping magnet |35 and relay |40 continues intermittently as the wiper steps over the grounded bank contacts. This action also steps the first digit indicators 5, B0, 10 and 80 to operate in synchronism to operate their armatures 58 and step by step restore the drum 43 to a position where the blank space is visible in the opening 44 of the face plate. When wiper |50 reaches its home position contact |52 ground will no longer be present on this bank contact, the rotation of the switch S ceases, and magnet |35 and relay |40 iinally come to rest.

When the first digit indicator magnets have restored their associated numeral drums to a position where the blank space is visible, the

cams

8, 62, 12, and 82 again close their associated cam contacts I3, 63, 13 and 83, thereby completing a circuit from the ground at cam I3 of the sending station in series through all remaining first digit cam contacts through conductor 36 to relay |45 and battery, thereby energizing this relay and closing its armatures |46 and |41 on ground. At armature |46 ground is extended over conductor 39 to pilot lamp 'I of the first digit indicator at the sending station, the illumination of which now indicates to the operator that all of the indicators of the rst digit at each one of the sending stations are in their normal position. Ground at armature 41 is extended over conductor 39 in series through all the intermediate register senders which operate in a similar manner as the rst register sender to restore the associated indcators to normal position. Finally the last register sender switch S is operated to step the wiper 250 across the bank contact and restore it to normal and consequently its associated last digit indicators at each one of the receiving stations, resulting eventually in the energization of relay 245. The energization of relay 245 closes its armature 248 and extends ground over conductor 40 to relay 25 thereby energizing this relay to open its armature from its grounded back contact 26 and open the locking circuit of relay 20. Y Relay 20, upon falling back, opens its locking armature 2l and at armature 22 again connects ground to the common conductor 50. At armature 246 relay 245 grounds conductor 4I to light the pilot lamp I1 indicating that all of the indicators of the last digit at each of the receiving stations are in normal position, and notifying the attendant by the illumination of all the pilot lamps that the apparatus and the indicators are in condition to again receive the transmission of a number.

Should the operator at the sending station during the setting up of a number accidentally press the wrong key or transmit the wrong number, he can operate the key R and thereby cause the restoration of all the apparatus including the indicators back to normal position the same as if he was releasing the connection after having transmitted a number. In this event he would have to begin over again and send the digits of the number in their regular order as originally intended. It will also be understood that the transmission of the digits and the setting up of them on the key set takes place as fast as the operator can depress the keys or if he may desire he may do this as slow as he Wishes. The register senders operate as fast or as slow as the indicators at the receiving stations and the reception of the number on all the indicators is practically simultaneous.

Having described the invention, what is considered to be new and is desired to be protected by Letters Patent will be set forth in the following claims.

What is claimed is:

l. In a signaling system, a signal transmitter and a signal receiver, means for storing signals for transmission by the transmitter to the signal receiver, the signal transmitter and the signal receiver each having a predetermined normal position, means for moving the transmitter from normal to other positions, means for erasing stored signals, means responsive thereto for bringing the signal transmitter and the signal receiver each into its normal position, and means for preventing the storing of further signals until the said restoration to normal position has been completed at both devices.

2. In combination, a plural digit storage device, a transmitter for transmitting the stored digits under control of the storage device, and receivers each receiving one of the transmitted digits and operated in accordance therewith, means effective when the stored digits are erased for bringing each receiver to a predetermined normal position, and means for preventing the storing of further digits in said storage device until each of said receivers has been returned to its normal position.

3. In a signaling system, a transmitter comprising a plurality of register senders, means in said transmitter common to said register senders for registering successive digits in successive register senders, a receiving device for each register sender, means in each register sender for immediately transmitting only the initial pulse of each registered digit to its corresponding receiving device as soon as each digit is registered, and a revertive impulse control arrangement between each receiving device and its corresponding register sender for thereafter permitting the transmission of the remaining pulses of each registered digit to independently operate said receiving devices in accordance with the registered digits.

HARRY E. HERSHEY.