US2390222A - Unit transmitter printing and signaling system - Google Patents

Description

Q-ec. 4, 1945.

M. W. MUEHTER TRANSMITTER PRINTING AND SIGNALING SYSTEMS UNIT Original Filed Jan. 12, 1938 '7 Sheets-Sheet 1 INVENTOR M.W.MUEHTER ATTORNEY Dec. 4, 1945. M. w. MUEHTER 2,390,222,

UNIT TRANSMITTER PRINTING AND SIGNALING SYSTEMS Original Filed Jan. 12, 1958 '7 Sheets-Sheet 2' INVENTOR M w. M UE HTER BY 4 a ATTORNEY Dec. 4, 1945.. M. WQMUEHTER' UNIT TRANSMITTER PRINTING AND SIGNALING SYSTEMS Original Filed Jan. 12, 1938 7 Sheets-Sheet 3 v N m m mm mm.

555 :v mm R T o O H H mm M Now 1 mohbu pmo mmm ATTORNEY Dec. 4, 1945. M. w. MUEHTER 2,390,222

UNIT TRANSMITTER PRINTING AND SIGNALING SYSTEMS Original Filed qan. 12, 1938 7 Sheets-Sheet 4 :N.W. DELINQUENCY O l q INDICATOR TO FIG -ro FIG.

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iMINUTE IMPUL E CONTACTS 'f'TO no.2

INVENTOR M.W. MU E HTER FIG. 4

ATTORNEY Dec. 4, 1945. M. w. MUEHTER UNIT TRANSMITTER PRINTING AND SIGNALING SYSTEMS Original Filed Jan. 12, 1938 7 Sheets-Sheet 5 .PDO PDU .Ezufiz 529: E nzrrukmam ozEo h a :n 06 mmw F I l I l I l I l I l I l l I ll w l .L FL muhzEa mu 5% 55 25.?

TO FIG INVENTOR M. W. M UEHTER BY MM ATTORNEY Dec. 4, 1945. w. MUEHTER 2,390,222

UNIT TRANSMITTER PRINTING AND SIGNALING SYSTEMS Original Filed Jan. 12, 1938 7 Sheets-Sheet 6 FIG.- 6

N.W. TRANSMITTER F. A. TRANSMITTER INVENTOR M.W. MUEHTER ATTORNEY Originai Filed Jan. 12, 1958 7 Sheets-Sheet 7 rl.. rlL

unzm ZOTCQKOPMUE wvm 304- muh 3 lNVEN TOR M.W. MUEHTER BY 4 4 M ATTORNEY Patented Dec. 4, 1945 UNIT TRANSNHTTER PRINTING AND SIGNALING SYSTEM.

Manfred W. Muehter, Nutley, N; J., assignor to American District Telegraph Company, Jersey City, N. J a corporation of New Jersey Original application January 12, 1938, Serial No.

184,595, now Patent No. 2,309,660, dated February 2, 1943.

Divided and this application August 3, 1940; Serial No. 350,622

8 Claims.

This invention relates to systems for operating printing recorders and more particularly to an improved signaling and'recordingsystem of the unit transmitter type based on the system disclosed in applicants prior patent application Ser. No. 578,572, filed Dec. 21, 1934, and allowed July 29, 1937. This application is a division. of the applicants application Ser. No. 184,595,- filed Jan.

12, 1938, for Unit transmitter printing. and signaling system and which has become Patent #2,309,660, dated February 2, 1943;

The objects of the invention are to provide, separate alarm and supervisory circuits, both working in conjunction with the same printer and providing for preferential operation of alarm signal transmitters. This increases the reliability of the more important alarm service, as all alarm transmitters are concentrated on their own circuit which will, therefore, be shorter and less exposed to troubles. The preferential feature insures that alarm signals will under all normal or trouble conditions be given first consideration in recording, thereby eliminating possible delay in reception.

Automatic trouble adjusting means are, provided which, in the case of a break of one or all of the three circuit wires, adjust the system for operation under that condition. Independent means are provided for the alarm and the supervisory circuit and the system is capable of maintaining operation of all transmitters even with breaks in all of the three wires ofboth circuits at the same time. Automatic restoration is effected as soon as the particular circuit is repaired.

Another improvement relates to the mode of operation of certain types of transmitters arranged for transmission of repeated alarm signals, as in the case ofwaterflow transmitters. These transmitters are arranged with a code Wheel having an alarm code on one side of the wheel and a restoration code on the other half as in the case of supervisory transmitters. If the transmitter is also arranged for three round alarm signal operation, for instance, the. first round will come in as an alarm signal, the second as a restoration signal and the. third again as an alarm signal, each signal being transmitted by one half of the wheel. An object of the present invention is to provide, at the receiving station, converting means for converting this restoration signal. into an alarm signal and recording; it; as such, and perform same as an alarm signal, viz., tap out. the code on the songs. In case of agenuine restoration signal,

' hereinafter.

only the one restoration signaliis. transmitted;

fective. for a restoration signal and'failsto tap out.its

I code on the gongs, in whichcase the complete restoration signal. will be transmitted. at the higher speed; This arrangement considerablysimplifiesthe designofthese transmitters which would otherwise require a. double set of code Wheels and coding contacts and an additional geared controlling cam.

Various selective and other. novelifeatures will be apparent fr0m the, following. representative description.

This system is-calleda unit'transmitter system because it makes use of an individual transmitter for each alarm or supervisory device from; which indications are required. Each transmitter. is directly attached to the particular device which operates it. The various transmitters of asystem are interconnected by means of one or' more three-wire loop circuits which originate at; and return to the control center.

The transmitters operate. in conjunction with control equipment located, at the control center in a non-interfering and'successivemanner to records. signal on a printer recorder' at the control center and to perform other functions;

The transmitters are driven. by, current impulses from the. control station. The: basictype of transmitter is. the supervisory type: Ith as two codes arranged on the circumferenceofits code wheel. One code is transmitted when.the associated device is operatedto its alarm condi tion and the other when it is restoredto its normal position. The difference in the two codes consists in four additional. teeth. in the. second digit for the. restoration signal. The. impulses transmitted are strong, andweak, weak. impulses representing spaces. The starting of. the trans? mitter is controlled through atransfer cam switch, theposition of which is reversed during the transmission of a signal, in conjunction with the transfer switch. operated by the supervised device. Other transmitters will be referred to Code impulses. from. the transmitters control the impulse operatedtype carriers at the control station,

A- delinquency indicator is providedlconsisting of a stepping mechanism'whichis advancedone step every minute and restored automatically when a night watch signal comes. in. If the night watch signal fails to come in=witliin the proper timeinterval; an associated} transmitter may be operated to record a delinquency signal on the tape. Operation of a night watch box will then reset the delinquency indicator and record a restoration signal.

All supervisory signals, that is, signals from sprinkler supervisory devices and delinquency signals, are arranged to register on a totalizer which is advanced one step when one of the above-mentioned devices runs in an alarm signal and is moved back one step when one of the devices is restored to normal. It thus indicates at all times the number of abnormal supervisory devices.

A ground detector relay is connected to the center of the ungrounded battery. The other terminal of the relay coil is connected to ground. A ground on any external circuit will operate this detector relay and give a lamp and buzzer signal. The buzzer can be silenced by turning the associated lamp switch. When the ground is removed from the system, the light goes out and the buzzer rings again until silenced by turning the switch back to normal.

Since no other ground exists on the system except through the high resistance coil of the ground detector relay, a single ground will not interfere with the operation of the system especially as the ground connection is removed from the detector relay while a signal is being transmitted.

In the drawings, the figures show diagrams of the system, transmitters and signals.

Figs. 1 to together show the control station, printing recorder and two types of transmitters.

Fig. 1 shows the supervisory circuit and transmitters.

Fig. 2,shows the alarm circuit and transmitters.

Fig. 3 shows principally the control station means for supplying the impulses to the transmitter circuit and the type carrier setting means.

Fig. 4 shows principally the routing relays for supplying the impulses to the respective typecarrier setting means.

Fig. 5 shows the printer and totalizer.

Figs. 6 and '7 respectively show the nightwatch and fire-alarm transmitters.

Figs. '8 to 13 are diagrams representing strong and weak impulses of types of signals as titled, the upper solid line portions representing strong impulses, the dotted lines representing weak impulses, the number stated being the transmitted number.

Fig. 14 is a diagram showing relative placement of the several figures of the drawings to form the complete circuit diagram. The transmitters and their operation are similar to those disclosed in the above-mentioned application.

The mechanical elements of the printer are similar to well known types of printing recorders and to those shown in my application Ser. No. 22,680, filed May 22, 1935, and the application of Johnson et a1 Ser. No. 507,898, filed Jan. 10, 1931.

Supervision The supervisory circuit for the common and starting lines of the supervisory circuit can be traced as follows: From plus battery through contact 30I (upper left of Fig. 3) over conductor I38, out over the ST loop and back to the control center, through make contact IOI of relay I25, through relay I02 over the C line to minus battery (Fig. 1). Relay I02 is normally held energized through this circuit to thereby supervise the ST and C lines.

The supervisory circuit for the R line can be traced from plus through the right hand winding of main starting relay I03 (upper right of Fig, 1), back contact I04, left hand winding of relay I03, through the R line, and corresponding contacts I05 (Fig. 1) of the line transmitters, back to the control center through make contact 100, through the middle windin of relay I03, through the coil of relay I01 (lower right of Fig. 1), over conductor I08, through contact 302 (upper part of Fig. 3) to minus battery. Relay I0! (Fig. 1) is normally held energized in this circuit to thereby supervise the "R line- Although cur-- rent is flowing through all three windings of relay I03, it is to be noted that the middle winding has a number of turns equivalent in effect to the sum of the other two windings of relay I03 and is connected opposingly so that the efiect on relay I03 is neutralized.

Similar supervisory circuits can be traced for the alarm circuit involving supervisory relays 202 and 201 at the lower right of Fig. 2, as will be evident from the above.

Transmitter start The transmitter of Fig. 1 is similar to that of applicants Patent No. 2,109,273, issued February 22, 1938, and comprises a pair of stepping motor magnets, I0 and I I, adapted to actuate the armature I2. A shaft carrying a master cam I4, a transfer cam I5 and a code wheel I6, which may be toothed on the alarm side as shown in Fig. 8, and on the restoration side as shown in Fig, 9, is rotated, step by step, by a pawl and ratchet, not shown, under the control of armature I2.

Assuming, by way of example, that the operation of the supervisory transmitter of Fig. 1, shown connected to the supervisory line ST at the upper left hand side of Fig. 1, is initiated by actuation to the right of the transfer element of the device switch I09 of the associated device to be supervised, a circuit will be closed from the ST line, where plus polarity of the battery is available at contact 30I (Fig. 3), as has been explained, through the device switch I09, the normally closed contact III] of the transfer cam contact, through the normally closed master cam contact III of switch I26, and the right hand magnet coil of the transmitter to the C line where minus polarity is available as shown. Th transmitter magnet is energized and attracts its armature closing its contact H2 and engaging the next tooth of the ratchet wheel preparatory to advancing it one step when subsequently deenergized. By closing contact II2, the R line is connected through contacts I05, I05, H2 and the armature I2 to the tap of the right hand transmitter coil and the current flow in the out side of the R line is considerably increased. This has the effect of increasin the current through the two outer windings of relay I03 to such a degree that relay I03 will pick up.

Relay I03 locks from plus in through its right hand winding, contact II3, resistor II4, over holding conductor H5 and through contact 303 of relay 3I5 to minus. Relay I03 also energizes relay II6 from minus through contact II! and its middle winding. Relay IIo opens the running line at contact I04 and also looks in from plus through its left hand winding, make contact II8, resistor II9, to holding conductor II5. The break in th R line causes relay ID! to drop out and light a lamp I01 through an obvious circuit.

asoaeaa.

Start of pulsing relays:

.The main pulsing relay is 304 which operates in. conjunction .With relay 305. These relays start their operation as soon as contact. I20. of relay. I I6. closes a circuitv from plus over conductor I2I,.

through contact 306 of'relay 3J5, over conductor 301, through contact 40I of relay 432; over conductor 402, through resistor 3082 and the lefthand winding ofrelay 304 to minus. Relay 304 operates and by opening its back contact 30.9removes the. shunt from the left handwinding of relay 305' permitting itto operate from minus through resistor 310, left handwinding of 305 to. plu obtained from conductor. 402 astraced above. When contact 3 of relay305.closes,- the winding. ofirelay 304 is shunted out and re1ay.304 deenergizesv with a slight. delay. At'. this time a circuit is closed from plus through contact 312 of relay 305, contact 3I3; conductor 3|4', back contact 222, conductor 3M, contact I23, over conductor I 24 and through the coil of the supervisory master relay 3 l 5 and contact 3I0f to minus. Relay 3I5 operates. This relay closes a locking circuit for itself through contact 3'lI.to plus over conductor 402 to keep itself energized when contact.3l2.of relay 305 or contact 3I3 of relay 304 opens. B opening its contact 301, relay 3I5 removes plus battery from the starting line ST causing the transmitter previously operated to release its armature and advance its ratchet Wheel one step. It will be noticed that this. happens after a time delay following theoperation ofrelays I03 and H0, giving sufilcient time to the transmitter magnet to operate properly and for other functions which will be subsequently explained. The opening of the starting line causes the release. of relay I02.

The first step of the transmitter changesv the position of the master cam contacts to the, operated position. The right hand magnet coil of the transmitter'is now connected to the out side of the running line R through contact I252of switch I4 while the left hand magnet coil is connected to the in side of the running line R through contact I23 of switch I4". The running line R being open on the out side at contact I04 of relay H6, a-nd'on the in side atcontact 3020f relay 315 which has been opened, no current is supplied to eitherof the coils of the transmitter at this time.

Impulses transm tted through the; R Zine;

Following the release of'main impulse relay 304 which energized relay 3t5, the coil of relay 305 is shunted by back contact309 causing relay 305 to-release with a slight delay. With contact 3' of relay 305 opening, the shunt is removed from relay 304 permitting it to energize again. At this time an impulse is transmitted to the transmit.- ter, the circuit of which can be traced as follows: from plus through make contact 3l8 of relay 304, the coil of marginal operating relay 3I9, conductor: 3.I'0'=, contact 320, over conductor 321; make contact. I 2.1. of relay I03, lefthand winding of relay I03, the R line, in series with the master ca-m'contactssimilar to I05. of intermediate transmitters, if there are any, through contact I25 of the operated transmitter and its right hand-magnet coil to. the C line and minus. The-transmitter magnet. is thereby energized. As-the-code-wheel contactsof the transmitter are notyet closed, this impulse wilLbe of low intensity, not capable of operating; the marginal relay 310. However, enough current flows through the left hand winding.of.:r.elay. I03;to;keep.it energized; It will now be. shownthatrat this time relay I03. has;sto;de-- pend. on this leftrhand winding; forits; energize. tion. At the time-relay. 3 I5.is;energized thelocke ing circuitfor theright handwinding o rela 5l03r is. transferred from minus battery through con-r tact 303. of relay 3I5' to minus battery through contacts 322 of relay 3I5and= 3.24 of: relay-'4. contact 323 of relay 305*.inmultiple with-contact 324'being; open at that time; It may be-noted. thattcontacts 303 and 322 are'of'themake-before? breaktype thus preventing momentary interrup tion of the-holding circuit of relay.-I.03 when-re;.-- lay 3I5 picks up. A shorttimeafterrelay-304 is reenergized, at the time ofthe transmissionof an impulse over. the-R line, relay 305. is-.also;'reenergized as relay-304 again removes the shunt from. the winding of relay 305. Both contacts-4:323'and' 324 are. thus" opened depriving: theright; hand. winding of relay I03 of current. However, ass-indicated above relay I03 stays energized because of the current'fiowing, through its left hand wind.- ing.

Relay 30.5 energizing againshunts the coil. of main impulse relay 304 which dropsoutwitha slight delay. This successive operationof. relays 304 and 305. now continues for the full time of the 77 signal transmission. Every time 304 releases, the

line impulse is interrupted by the opening of its contact 3I8, and the transmitter releases advancing its ratchet wheel one step. Since back contact 324 of impulserelay 304=ris arranged to close prior to'the-opening. of frontcontact:3I8-,- the locking circuit forrelay I03. is not even-me.- mentarily interrupted.

First codingimpulse In this way the transmitter will beoperated step by step until the -first.tooth of the first .digit of the code Wheel. closesits contacts shuntingthe upper portions of the transmitter. magnet. coils. The next impulse-will, therefore, be of consider.- ably greater intensity and will be asignal impulse sufiicientto operate the marginal relay 319.. By closing its make contact 325; relay. 3I9 energizes the coding relay. 403 fromminu over conductor 326, through its two windings in series andto plus at conductor 301. Relay 403 looks in from.minus through its contact 404. andits. left hand wind ing to plus over conductor, 307; which is vnowv connected to plus as above explained. Fig. 81shows an example of a supervisory alarmsignal.

First impulseto' printer When impulse relay 304subsequently releases, the first digit type carrier stepping magnet RSI, Fig. 5, receives an impulse from plus through back contact 321 of relay 30.4; over. conductor 3Z8Icontact 405 of relay 403, back contact 406 of the. first shifting relay 432 (bottomof Fig. 4),.conductor 401 and the coil of'the first'stepping magnet! PSI to minus. The latter advances itsratchetwheel one step and'brings the stepping wheel retaining pawls into operative position to prevent retrograde movement and also closes latch contact L which stays closed until the printer has been reset to normal.

Sending coding impulse. from supervisory transmitter.

When impulse relay 304 is energized" for the next line impulse, a circuit is also closedfrom plus through make contact 329 01 relay 304; over wire 330, break contact 403 of relay'422i break contact 409 of relay 432-; right hand winding of the routing relay 4"), over conductor 4H and latch contact L-of the printer-to minus." Relay is thus energized. As relay 3l9 is again energized, due to the fact that all supervisory transmitters have a number of consecutive teeth in the first digit, a circuit is closed from plus through contact 361 of relay 3l5 over conductor 369, contacts 4H of relay 430, 2, of relay 432, 413 of relay 423, 414 of energized relay 0, conductor 4I5, contact 33l of relay 3l9, conductor 332, contact MS of' relay 412 and the left hand winding of the first converting relay M1 to minus. Relay 1 is thus operated and locks in from minus through its contact 8 and right hand winding to plus over conductor 369.

When relay 304 subsequently releases, a circuit is closed from plus through its contact 333, over conductor 334, contact 419 of relay M0, the left hand winding of relay 410, over conductor 420 and through contact 335 of relay 315 to minus, thereby holding relay 410 energized. It is to be noted that contacts 329 and 333 of relay 304 are of the make-before-break type so that the circuit for the left hand winding of relay 0 will be closed before that of the other winding is opened. Another circuit is closed at this time from plus at conductor 334 through break contact 42! of relay 432, make contact 422 of relay M9 and through the right hand winding of relay 423, conducto 420 and contact 335 of relay 3l5 to minus, thus operating relay 423.

At the same time another impulse is transmitted to the first stepping magnet PSI, of the printer over the previously traced circuit through back contact 321 of relay 304.

The third and following code impulses of first digit When the next impulse is transmitted to the line circuit back contact 333 of relay 304 is opened deenergizing the left hand winding of relay 4E0, and relay 4l0 releases since the previously traced operating circuit through make contact 329 oi relay 304 and back contact 408 of the third shifting relay 423 for the right hand winding of relay M0 is no longer closed. However, relay 423 remains energized from plus at conductor 330, through contact 424 and the left hand winding of relay 423 to minus at conductor 4| I. When relay 304 releases again, another impulse is transmitted to the first stepping magnet PSI of the printer. The former operating circuit of relay 423 is now open at contact 422 of deenergized relay 4l0, but another circuit is closed instead through contacts 445 of relay 4| 0 and 446 of relay 423 to plus at conductor 334. The following impulses of the first digit will have no other effect except operating the transmitter and the first stepping magnet of the printer for additional steps. Relay 423 will remain energized through the right hand winding during the time the relay 304 is deenergized and through its left hand winding during the time relay 304 is energized.

First shifting space When the space following the first digit group of teeth is brought into position opposite the coding wheel contacts, these will remain open and the subsequent lin impulse will be of low intensity, as indicated at the sixth impulse of Fig. 8. This low intensity impulse is not capable of operating marginal relay 3l9 and the low intensity impulses correspond to the absences of impulses in most other systems, and are herein referred to as spaces as contrasted with the stronger signal impulses. Both windings of coding relay 423 willnow be connected in multiple as follows: the

right hand end of the winding is connected over conductor 326 through contacts 335 of relay 319 and 336 of relay 304, to plus at conductor 402, the left hand end being connected to plus at conductor 301, while the common in the middle is connected to minus through contact 404. The flux set up by the two equal windings will be of opposing direction neutralizing one anothe and cause relay 403 to release.

When relay 304 subsequently releases, a circuit is closed from plus through contact 333 of relay 304 over conductor 334, through contacts 425 of, relay 403, 426 of relay 0, 421 of relay 423, 428 of relay 432, resistor 429, conducto 504, and through the right hand winding of the second shifting relay 430 to minus, operating relay 430. No impulse is transmitted to the printer at this time as contact 405 of relay 403 is open.

Second digit The next impulse transmitted over the line ,will again be of a greater intensity as the first tooth of the second digit operates the code contacts to the closed position. Relays 3l9 and 403 are operated as before. The above traced circuit of relay 430 is interrupted at this time but another circuit is closed fOr its other Winding from plus at conductor 330 through make contact 43l of relay 430, the left hand winding of relay 430 to minus at conductor 4i maintaining relay 430 in an energized position. At the same time, a circuit is cld'sed for relay 432 from plus at contact 43l of relay 430, through the left hand winding of relay 432 over conductor 433, through contact 331 of relay 355 over conductor 4 and through latch contact L in the printer to minus, operating relay 432. This relay locks in from plus through its other winding and contact 434 to conductor 4i I and contact L. Contact 40! opens but multiple contact 435 of relay 423 being closed, the circuit for the pulsing relays and relay 3l5 remains closed.

When relay 304 subsequently releases, an impulse is transmitted to the second stepping magnet PS2 of the printer from plus through contact 321 of relay 304, over conductor 328, through make contacts 405, 436 of relay 432, 431, 438, over conductor 439 and through the coil of the second stepping magnet PS2 to minus. Relay 430 is maintained energized through its right hand winding but now from plus at conductor 334 through make contacts 440 of relay 403, Ml of relay 430, and 442 of relay 432.

Subsequent code impulses will operate the transmitter and second stepping magnet of the printer for additional steps but no change in the routing relays M0, 423, 430, 432 will occur until the space following the second code digit causes the next shift impulse, relays 403, 423, 430, 432 remaining energized in the meantime. 3

Third digit Relay 403 is deenergized when the low current lmpulse following the second code digit is transmitted over the line. When relay 304 releases following it, relay 430 is deenergized as the circuit of its right hand winding is opened due to the opening of contact 440 of relay 403.

When the next impulse is transmitted to the line circuit, the first tooth of the third digit closes the code wheel springs of the transmitter again, causing relays 3l9 and 403 to operate. At the same time the relay 0 is reenergized from plus at conductor 330 through contacts 443 of relay 430, contact 444 of relay 432, and the right releases.

.hand winding of relay M .to minus at conductor :4,

When relay.304 subsequently releases, relay 4| 0 remains energized through its left hand winding and contact '4! as before. At the 'same time, relay 423 is deenergized since the circuit for its right hand winding is Open at contacts 445 of relay 4|0 as well as 4'2I of relay 432. 435 of relay 423 is opened but this has no effect since it is in multiple with contact 44'! of relay 4| 0 which is now closed, maintaining the operating circuit of the pulsing relays and relay 3l5 closed. Furthermore, an impulse is transmitted to the third stepping magnet PS3 of the printer which can be traced fromplus through contact 321 of relay 304, over conductor 328, through contacts 405, 436, 448, over conductor 449, and the coil of the third magnet PS3 to minus. The following code impulses of the third digit will operate this stepping magnet and the transmitter for additional steps while the routing relays maintain theirposition with relays M0 and 432 energized.

Fourth digit Following the third digit, a space is encountered by the code'springs of the-transmitter code wheel causing a low current impulse :on'the line, not capable of operating relay '3l9. Relay1403 When relay 304 subsequently deenergizes,relay 430 is energized again from plus at conductor 334 -through contacts 425 of relay- 403,

Contact 448 of relay M0, 442 of relay 432, resistor 4'29 and right handwinding 'ofrelay 430 to minus.

When the next impulse is transmittedoverthe line, the first tooth of the'fourth digitwill cause, operation of 'relays 3f9 and--40*3. At the sam'e time relay M0 is deenergized as the circuit for its right hand winding is open atback contact 443 of relay 430. Relay 4'30,however, :remains energized through its make contact 43l as earlier described.

Contact 441 of relay "M0 is now'o'pen butis shunted by contact4'49 of relay'403 thereby maintaining the circuit for the pulsing'relays and relay3l5 closed.

When relay 304 subsequentlyreleases, an impulse is transmitted to the fourth stepping magnet PS4 of the printer from plus through back contact 321 of relay 304, over conductor "328 through contacts 405 of relay 403, 436 of relay 432, 43! of relay 430, 450 of relay'423, conductor '45! and the coil of the fourth tepping magnet PS4 to minus. The following impulses of the fourth digit advance this magnet and the transmitter a corresponding number of steps.

Printing and clearing operations When a low current impulseis transmitted over the line due to the space following the last tooth of the fourth digit of the code wheel, relay 3!!! again fails to operate causing the release of relay 403. Contact 449 of relay 403 now .opens but this has no immediate effect as it-is shunted by contact 338 of relay 304. 304 subsequently releases, this shunt isremoved. With the subsequent release of relay 305, there is an alternative path from plus through its contacts 3I2 and 339 (of relay 315) for energizing the pulsing relays and the energizing circuit for relay 315 is opened at contact 3l2 causing the pulsing relays to cease operation and relay 31.5 to release. Contact 361 of re1ay'3l-5 opens and removesplus from the holding conductor.359 of However, when the relay tact 452 of relay 430 which is still energized from plus at conductor '334 through contacts 453 of relay 423, 44! of relay '430, 442 of relay 432, resistor 429 and the right hand winding of relay 430'to minus. At the instant relay 305 releases, a circuit is closed from plus through contact 333, conductor 334, contacts 425 of relay 403, 426 of relay 4l0, 454 of relay'423, over conductor 455, through contact 340 of relay 305, over conductor -34l, through contact 456 of relay 430, over conductor 451, through the printer cut-out contact PC and'the printer magnet PR to minus. The printer magnetis energized causing the signal already 'set up on the four typewheels of "the printer to be printed on the'tape.

The totalizer At this time it may beexplained'that the-sec- 0nd typewheel of the printer operates a cam 50! together with contacts 50! and 502. For the chosen designations of the printer wheels the cam 50! is so arranged that normally, and if magnet PS2 is operated for l, 2, 3 or 4 steps, contact 50| is closed and 502 is open and if operated for more than 4 steps, contact 502 is closed'and .50I is open. Assuming that magnet PS2 was operated 3 times (corresponding to an alarm signal with 3 as the first numeral of the device number) the following circuit can be traced at the time the imprint magnet is operated: from conductor 3'4I to which plus polarity'was traced above, through contact 458 of relay 430 over conductor 459, through contact 50! and the addingmagnet 5I0 ofa so-called totalizer over conductor 505, through contact 463 of relay 4H, conductor 464 andcontact 342' of relay M5 to minus, operating the totalizer. The totalizer is a step-by-step device operating a common indicator shaft in either direction, depending on Whether actuated by one or the other of its magnets. =It is used to indicate the total number of supervisory devices in an abnormal condition at anygiven time. The second typewheel prints simple numbers in its firstprinting positions and duplicates these numbers with the indication Rest. meaning restored at the other positions. Therefore, when the same transmitter which sent the signal of Fig. .8.sends.a restoration signal (Fig-.9), thesecond digit would have 7 impulses. Thesecond typewheel would .then bring Rest. 3 into ,printing position. The subtracting magnet of .the totalizer would'then .be energized instead of'the addingmagnet, setting the indicator back .one step.

A multiple circuit, may also be traced from plus at conductor 459 through conductor 459' the resetting magnet 465 of the night watch delinquency indicator, which will be mentioned again later, over conductor 466and throughthe lower windingof specialattention relay 343 to minus. Magnet .465 .doesnot operate in this circuit because of the high resistance of the winding of relay343, .but this relay does, locking in from ,plusthroughits upper winding, its contact 344 andcontact 345 of relay 305 to minus. Through obvious circuits relay $343 operates a light .348 and anbuzzer 348 by closing contacts 346 and .341.

Thisrelaywill stay energized and maintain its visual and audible signal until the attendant op- ..erates a keyswitch operating a transmitter which may besimilar to that of Fig. 6 and which "records an acknowledgment signal .on the tape. Contact 345 of relay 305 is opened by hand or relay 4H, but plus is still being supplied byconmay be .opened'by this'transmitter'momentarily by means of a cam 345 (Fig. 6) on the transmitter shaft which operates near the end of the transmitter cycle, causing relay 343 to release. This switch and cam would not be present on the night watch transmitter mentioned hereinafter.

When the imprint magnet'operates, it closes its contact 503 and connects minus battery over conductor 504 to the left end of the right hand winding of relay 430 causing a shunt across this winding and making it release with a slight delay. Contacts 456 and 458 open and deenergize the imprint and totalizer magnets, and the armature of the imprint magnet releases and operates means which move the paper tape forward one step.

Opening of contact 452 removes plus from locking conductor 369 of relay 4I'I, causing it to release.

A circuit is now closed from plus at conductor 34I through contacts 460 of'relay 430, 46I of relay 432. conductor 462. coil RL of the release magnet in the printer. through contact 506 to minus, operating the release magnet. This magnet releases and restores the printer typewheels to normal and opens latch contact L. The latter causes relay 432 to deener ize by opening the circuit of its right hand winding.

When contact 40I of relay 432 closes the circuit of the pulsing relays. these will start their operation with the energization of relay 304. It will be noted that the operation of the pulsing relays has been stopped until the completion of the printing and clearing operations of the recorder. This feature makes these operations reliable and independent of the speed and impulse duration of the pulser and, in conjunction with the printer cut-out contact PC. which is arranged. to open automatically when the printer head is lifted. for changing paper for instance. prevents further signals from going in without the possibility of mutilation of line impulses, which could occur. were the cut-out switch connected directly into the pulsing circuit. When relay 304 operates for the first time after restoration of the printer. no impulse is transmitted to the line as contact 320 of relay 355 is open. However. the starting relay I03 has been maintained energized as it locking circuit through its right hand winding. its contact II3. resistor H4 and conductor II5. has been transferred by contact 303 of relay 3I5 directly to minus. Subsequently. relay 305 is ener ized and 304 deenergized a ain. At this time the original operating circuit for relay 3I5 is closed from plus through contacts 3I2 of re ay 305. N3 of relay 304. conductor 3'4, contact 222 of relay 2I6. Fig. 2. conductor 314. contact I23 of relay H6. conductor I24. coil of relay 3I5 and back contact 3I6' of relay 3 5 to m nus. unless a signal is waiting to be recorded on the alarm circuit. in which case contact 222 is opened and 223 closed. as wi l be ex ained with more detail later in connection with the referential arrangement for alarm signa sv Assuming that t is is not the case. relay 3I5 is ener ized and a ain locks in through its contact 3|! to plus again available over conductor 402. Impulses are a ain transmitted through contact I21 of relay I 03 to the R line circuit as contact 320 of relay 3I5 is now closed. Except in cases where there is only one space between the last tooth of the fourth digit of the transmitter code wheel and its following home position, the transmitter is at this time still in the running condition, i. e.. with the master cam contacts in the operated position. The transmitter will again be operated by the line impulses which, however, will all be of low intensity since no more teeth are provided on the code wheel. Eventually the transmitter reaches its home position where the master cam I4 and its contacts are restored to the position as shown in the drawings and the R line circuit will be open except in a case where another transmitter is already connected to the R line waiting to transmit its signal, as will be explained later. The transmitter just operated is now again in its home position except that its transfer cam in the meantime has operated the transfer cam contact to the other side to be ready for a new start when the device switch is thrown back. In transmitting its signal, the transmitter code wheel has completed approximately one half revolution.

These above mentioned resetting impulses have no effect on the control center relays and printer. When the transmitter has disconnected itself from the running line and providing no other transmitter is already waiting on the R line to send its signal, the impulse circuit will be open when the next line impuse is transmitted. Relay I03 will release as its left hand winding will carry no current, the right hand winding likewise being deenergized since it in the meantime has been switched by'contacts 303 and 322 of relay 3I5 from minus to minus through the contacts 323 and 324, of relays 305 and 304, respectively, by the reenergization of relay 3I5, and as both these contacts are then open. The circuit of the middle winding of relay I03 is also open, as contact 302 of relay 3I5 is open. Relay I03 deenergizes and causes relay II6 to release by opening contact Ill and breaking the circuit of the center windin of H6. The common circuit of the pulsing relays and relay 3| 5 is at this time mainta ned energized from plus through contacts 3I2 of relay 305 and 339 of relay 3I5 in series but is opened at the time relay 305 releases the next time. When this happens, relay 3I5 restores to its normal deenergized position. The line circuit is now normal again and relays I02 and I0! pick up.

All relays are now in their normal position except relay 343 (right of Fig. 3); as explained above, it is deenergized by the operation of the acknowledgment transmitter.

The system is now ready for a new operation. If, for example, the device switch of the abovementioned supervisory transmitter of Fig. 1 is thrown back to the position shown, a new starting circuit is closed through the other side of the transfer cam contact starting a new cycle in the manner described above. The only d fference will be that a different code is transmitted, the restoration code having four more impulses in the second digit, as shown by Fig. 9. bringing the designation Rest. in position to be printed.

Night watch transmitter The operation of night watch transmitters (Fig. 6) which are also connected to the supervisory circuit, is the same as that of the superv sory transmitter as explained above except for the following points:

As shown by Fig. 6, the starting circuit is closed by a latch contact II. This contact is closed when the associated latch I2 is tripped as the watchman operates the box with his key 13. The latch contact is restored to its normally open position by a restoring cam I4 near the end of the signal. As before mentioned, the switch 345 and cam 345 is not used when this transmitter is used as a night watch transmitter.

' The "first digit of the code of this" transmitter consists of a singlertooth;followed'byran extra space in addition to the ordinary'digitzspace. As with the type wheeldesignations as chosen, the second wheel will ordinarily not be used for night watch signals, there will then be a'third space (see Fig. 10) causing no impulses to be directed to the second printer wheel anda blank space on the tape in that particular column. This will be apparent from the followingdescription.

The operation for the first high current impulse is the same as above described, "the first printer stepping magnet receiving oneimpulse bringing the designation night watch station into printing position. When the space is encountered during the transmissionof 'thejnext line impulse, however, relay 4!! is not energized, as contact 33! of relay 319 is open, and will not subsequently be energized during-thissignal as its circuit will be open at one or the other of the series contacts, M4, M3, 412 and 4H, all of which ar only closed simultaneously during the transmission of the second line impulse. However, routing relay 4| is operated at this time over the same circuit 'as previously explained for supervisory transmitters. -When relay 304 subsequently releases, relay 423 is energized likewise as before. No impulse is, however, transmitted to the first stepping magnet as 'relay 403 is deenergized and contact 405 open..

Due to the above mentioned additional space after the first tooth on the code wheel, the next line impulse is likewise of low intensity. However, relay M0 is deenergized at this timein the same way as explained for supervisory signals. When relay 304 subsequently deenergizes, relay 430 is energized likewise as before. As the following line impulse is again of low intensity, relays SW and 403 will not operate but relay 432 will, through the same circuit as above traced for supervisory signals. Contact 405 of relay 403 being open, no impulse will, however, be directed to the second printer wheel when relay 304 subsequently releases. At that time relay 430 is deenergized as described above after the second code digit of supervisory signals. The following third and fourth impulse groups also operate in the same way. At the time the imprint magnet is energized, however, the circuit to the totalizer is not closed as make contact 463 of relay 4" is open. A shunt is also applied to the lower winding of relay 343 from minus through contact 342 of relay 3l5, conductor 464, contact 461 of relay M1 to conductor 466. Thus, when plus is applied over contact 458 of relay 430 'tothe lower end of the coil of the night watch delinquency indicator reset magnet, as previously described, relay 343 fails to operate. The resistance of its winding being eliminated from the circuit of the reset magnet 465, current of sufiicient intensity will flow to operate it and reset the night watch delinquency indicator back 'to zero. The Hopkins Patents No. 1,942,814 and No. 1,942,815 show delinquency indicators. As-the delinquency indicator itself does not form part of this invention, it need only be mentioned that the minute impulses magnet 468 operatesa pawl mechanism which advances the main movable element of the delinquency alarm toward "an alarm position which will be reached if the night watch transmitter does not operate and energize reset magnet 465 (as explained above) in time to prevent it. If the alarm position is reached, said movable element will operate a special trans- .contact 12.

- mitterrconstructedfiandconnected as-in Fig. 1.

--Fz're alarm transmitter 'The'fire alarm :transmitter'shown in Fig. 7'is very'similar to the night watch transmitter. Being one of .the alarm transmitters, it is connected to the alarm circuit. It is actuated by a latch Latch contact 12 is tripped when the operator pulls on the lever 12a provided on the front of the station housing 121). This breaks the glass rod 120, and then withdraws the plunger 12d against the cam 12c of the latch 12, thus releasing the'latch 12. The spring '12 restores the lever, and the switch ii 'is restored to the normal position by the master cam l4 after transmission, even'though theglass rod has not been replaced. Subsequent operation can be obtained by pulling on the lever, even though the glass rod has not yet been restored. This transmitter is equipped with gears'to provide for a multiple round signal, i. e. the restoring and master cams and contacts are operated by a geared shaft which is geared to the main or motor shaft in such a way that said contacts willbe maintained in the operated position for six consecutive signals or three revolutions of the main or code wheel shaft, both sides of the code wheel having exactly the same code.

When the transmitter is started, due to the closing ofthe latch contact, it will operate the system in a similar way as explained above for the supervisory transmitters except that the operation will involve starting relays 203 and 2l6 and relays 202 and 20! (Fig.2) instead-M103, H6, l'02and l0l'(Fig.'1).

Startof pulsing relays for alarm signals ductor 3l4', contact 223 of relay 216, conductor 22.4,.and through coil of relay 3|5 and contact 3!.6 to minus, operating master alarm relay 3l5' whi h locksi t plu through contact 3H, conductor 301, contact 306, conductor Hi and contact 220 of relay 2P6. 'Impulses are now transmitted to the running line R, of the alarm cir- -cuit*throughcontact 320' of 'relay3l5, the conditions exactly corresponding to those of the su- -pervisory circuit as explained above.

The first digit-of the fire alarm code consists ;of-,tw0;teeth followed bya single space (Fig. 13) -It .will be:.remembered that the fact whether or mot-there is'a tooth after thefirst tooth of the firstdigit is decisive for operating the relay 4H or not. As -.there is-a tooth in this case'after the.first:0ne, the All relay will be operated, this ltimeithroughcontact36'! of relay M5, and con- -.Tl1uCt0l 369, instead of contact 36'! as previously. .Otherwiseethe operation is the same as explained above for supervisory transmitters with contact ..335'.taking theplace c1335.

Automatic speed change for gong operation When relay 430 is operated through resistor 429 and its right hand winding at the termination of the low current impulses following the first digit, relay 350 is operated in multiple therewith through contact 483 of relay 411 over conductor 351, its upper winding over conductor 355 and through contact 501 (Fig. 5) to minus. This contact is operated by a cam coupled to the first type Wheel. Normally and in the first and second position, sometimes also in the third position, contact 501 is closed and open in the other positions. Relay 350 locks in from plus through its contact 352, its lower winding, conductor 411 and through the printer latch contact L to minus until the printer has been restored after recording the signals. By closing contacts 353 and 354, relay 350 connects another winding of relay 304 and 305 in multiple with their normal operating windings. The pulsing speed of the relays is thereby reduced to a degree as consistent for gong operation. This for the following reason: The timing of the impulses depends mainly on the release time of the relays. As the release is caused by reciprocal shunting of the windings, it is slow on account of the induction effect whereas the pick-up is fast, representing a small percentage of the pulsing time. Now the decay of the flux in a shunted magnet follows the law =oe- (where o is the flux before shunting, t the time in seconds, R the resistance and L the inductance of the winding) or (where n is the number of turns and c is a constant for a given relay). This formula shows that the release time of a shunted relay can be changed greatly by changing the resistance or number of turns of its winding or both.

With relay 350 operated, the impulses to the second, third and fourth stepping magnets of the printer will also operate gongs. The circuit for these stepping magnets was traced above through contact 436 of relay 432. From there a branch circuit extends over conductor 469, contact 355 of relay 350 and through the gong or gong conductor 351 to minus.

Otherwise the operation is as explained for supervisory transmitters except that relay 432 is operated during the first high current line impulse of the second digit through contact 349 of relay 319 instead of 331 of relay 315.

At the time the imprint magnet is operated, the circuit to the tact 342' of relay keeps the shunt across lay 343 open, so it will attention signal.

Alarm transmitter maintained in operation after printin It will be recalled that relay 315 is deenergized at the time of the printing operation. This is not the case with 315' as its locking circuit through contact 311 is connected directly to conductor 301 which is now connected to plus at contact 220 of relay 216 as explained. However, the operation of the pulsing relays is stopped in the same way at this time as only relay 432 is energized and the contacts 401 of relay 432, 449 of relay 403, 441 of relay 410 and 435 of relay 423 are all open. The pulsing relays will, therefore, immediately start to transmit impulses over nat log g nat log 315' is open. This contact also the lower winding of reoperate and give a special the line circuit when contact 401 of relay 432 75 totalizer is not closed, as concloses following the printer resetting operation at which time the latch contact L opens and causes relay 432 to release. The locking circuit of relay 350 through conductor 411 and contact L, as explained above, is likewise deenergizcd. The higher speed of pulsing will then be resumed. At the same time, a circuit is closed from plus through contact 361 of relay 315, conductor 369, contacts 411 of relay 430, 412 of relay 432, 413 of relay 423, 410 of relay 410 and 411 of relay 411 and through the left hand winding of relay 412 to minus, operating relay 412 which looks in from minus through its contact 413 and right hand winding to conductor 369.

When the first high current impulse of the second round is transmitted, the operation starts again with relays 319 and 403 energizing aspreviously, etc. However, during the transmission of the second high current impulse, with relay 412 energized, a circuit is closed from plu at conductor 369, through contacts 41 1 of relay 430, 412, 413, 414, conductor 415, contact 331 of relay 3l9, conductor 332, contact 419 of relay 412, the middle winding of relay 411 to minus. This winding sets up an equal and opposing flux with respect to the right hand holding winding neutralizing the flux of the relay 411 and causing it to release.

The operating circuit for relay 350 during this round extends through contact 484 of relay 412 instead of 483 of relay 411. The rest of the operation is the same as for the first round.

When the printer has been reset after the second round, a similar circuit is closed for relay 412, which can be traced from conductor 369 through contacts 41 1-413, 410, 480, and the middle winding of relay 412 to minus. Middle and right hand winding neutralize one another causing relay 412 to release,

Relay 315 again remains energized. The third round operates exactly the same way as the first, operating relay 411 during the second code impulse and relay 412 after resetting the printer. The fourth round operates the same wa as the second, deenergizing relay 411 during the second code impulse and relay 412 at the end of the signal. The fifth and sixth round operate exactly as the first and second respectively so that relays 411 and 412 will be restored to the normal deenergized position ,at the end of the alarm signals transmitted by the transmitter,

After the printer has been operated for the last recording, the transmitter is kept operating until it reaches its home position where the master cam contacts of the transmitter are restored to the position shown on the drawings. Unless another transmitter is already connected to the running line, the following line impulse will find the line open causing relays 203 and 218 to release in the same way as described above for relays 103 and 1 16 for the supervisory circuit. Contact 223 opens, and when relay 305 releases the next time, opening contact 312, the circuit of the pulsing relays will be open as well as that of relay 315 which releases.

Waterflow signals to give one rotation of two rotations of the main or motor shaft. As will be later explained, the code wheel gives waterflow signals during one and one-half rotations of the code wheel and a restoration signal during one-half rotation of the code wheel. This allows the transfer cam, which is preferably on the motor shaft, to operate to effect transfer within a movement of 180 and 360 degrees from normal and requires that the master cam l4 operate the master switch at 2'10 and 360 degrees from normal. Hence the master cam is not symmetrical.

The waterflow switch (Fig. 2) may be operated by a flow detector, as is well-known, and when operated a circuit is closed from plus available on the starting line ST through alarm contact 2|0 of the transfer cam 14' contact assembly, through the normally open contact 209 of the W. F. switch and through thermostat heater winding 250 to negative available on the C line. The thermostat 25l starts to heat up. In case the W. F. switch is operated on account of water hammer in the piping system, it does not stay closed long enough to permit the thermostat to operate, which will then again cool off when the fiow detector restores its switch to normal, and nothing further happens. This arrangement thus prevents false alarms that would otherwise be caused by surges in the water pipes.

In case of actual operation, the thermostat finally closes its contact 25l thereby energizing the transmitter from plus at the starting line through contacts 2! 0, 25!, 2H and the right hand magnet coil to negative available at the C line. Further operation for water flow is the same as described above of Fig. 1.

In operating, the thermostat also moves a latch under the ti of pen spring 253 preventing it from later closing the associated contacts when the tooth of cam 254 has been rotated out of the way. This feature will be more specificall referred to when discussing tamper signals. At the end of the water fiow signals, the master cam restores the master switch to normal.

Water fiow signals are arranged for repeated operation and in the disclosed form of the system three signals are transmitted. Like supervisory transmitters, the waterflow transmitters have to transmit a waterflow alarm signal and in addition a restoration signal when the waterflow switch restores to normal, The code Wheel is cut for the alarm code on one side and the restoration code on the other side. This restoration code is, however, identical with the code on the alarm side except that the second tooth or the first digit is cut off. The first digit on the alarm side consists of three teeth followed by two spaces (Fig. 11). Arrangement is made for distinctive tamper signals. If the transmitter is operated on account of tamper, an additional high current impulse, later to be explained, is transmitted, by means of a cam and associated contacts, instead of the first spacing or low current impulse after the first digit of waterflow signals.

Waterflow alarm signals The first round of alarm signals is transmitted by the alarm side of the code wheel. As just mentioned, the first digit of the alarm code consists of three teeth followed by two spaces. The second tooth, as previously explained will operate relay M1, in the same way as above explained. The first stepping magnet operates three steps bringing the type of the words waterflow alarm into printing position. When relay 334 releases following the transmission of the first low current or space impulse after the firstdigit, relay 430 is energized as usual, also relay 350 as for fire alarm signals, if contact 501 is arranged to be closed in position 3 of the first type wheel, i. e if waterflow signals are to operate the gongs. The following impulse is again a low current impulse but relay 432 is not energized at this time as both contacts 331 of relay 3| 5 and 349 of marginal relay 3l9 are open. It is, however, operated through contact 349 of rela 3l9 during the first high current impulse of the second digit, starting the operation of the second stepping magnet. The second, third and fourth digits operate in the same way as for fire alarmsignals. If relay 353 is energized, these digits will also op erate gong 351. Relay 412 is likewise operated at the end of the printer operation. f

The water fiow transmitter is provided with gears which are arranged for a three-round alarm signal, i. e. one and one-half revolutions of the code wheel shaft. After the first alarm round has been recorded, the transmitter remains in operation and the second round is transmitted by the other side of the code wheel which is identical to the first except the second tooth'of the first digit is missing as in Fig. 12. This means that the second line impulse will be of low current intensity and the circuit which causes relay 4" to release on the second round of a fire alarm signal is ineffective due to contact 33! of relay 3l9 being open. However. when relay 304 subsequently releases, an impulse is transmitted to the first stepping magnet although contact 405 is open. This circuit can be traced from plus through contacts 321 of relay 304, 358 of relay 3l5, conductor 359,. contacts 4 8l of relay. 432, 482 of relay 4l0, conductor 401 and through the coil of the first stepping magnet PSI to minus so that the first stepping magnet willobtain three impulses as on the previous round. At the end of this signal, which otherwise operates the same as the first round, relay 412 is already energized and no change takes place as far as it is concerned. The transmitter continues to operate for its third round which again is transmitted by th'e same side of the code wheel asthe first as in Fig. 11. The second code impulse is of high current intensity and causes relay 4" to release as explained above for the second round of firealarm signals. Relay 350 is operated during this round through contact 484 of relay 412 instead of contact 483. At the end of. the third round, relay 412 is deenergized in the same way as for the second round of fire alarm'signals. After completing its cycle, the transmitter will restore its master cam contacts to the normal condition and cause the control center relays to restore as pre' viously explained.

It will be noticed that at the end of the third round of alarm, both relays 4H and 412 are deenergized and ready for a new countingcycle.

Waterflow restoration signal When the waterflow stops. the waterflow switch returns to the normal position as illustrated. A starting circuit can then be traced from line ST through restoration contact 252 of the restoration cam which is now closed (as the transfer cam has been shifted 540 degrees, 3 rounds of signals having been transmitted) through the normally closed contacts 209 of the W. F. switch and the tamper switch through contact 2 of the master switch and the right hand magnet to the- C line.

-tion is the same as explained before.

.The code will now be transmitted by the restoration s de of the code wheel as in Fig. 12. As will be recalled, the restoration code has a space following the first tooth. This means that relay 4 I! will not be operated during the transmission of that particular impulse. However, as explained above, in connection with the second round of waterflow alarm signals. the first stepping magnet will nevertheless obtain three impulses.

In. addition a circuit for the second stepping magnet is simultaneously closed. This can be traced from plus through contacts 321 of relay 304, 358 of relay 3| 5', conductor 359. contacts 48l, 485, 481, 488 over conductor 439 and the coil of the second stepping magnet PS2 to minus. When the first printing magnet receives its third impulse, the second stepping magnet receives its second additional impulse but through contact 486 of relay 423 instead of'485 of relay 4|0. It will furthermore receive two additional impulses when magnet 304 releases following the two low .current space impulses after the first code digit. It will then be operated in the regular way controlled by the second codev digit. It will be seen that the second steppngmagnet thus receives a total of four additionalsoecial impulses which with the addition of the three regular impulses later received. serve to advance the tv ewheel to the restoration position.- The rest of the opera- As both contacts 483 and 484 of relays 4|! and 412 respectively are open, relay 350. is not operated. the puls ng speed is not changed nor are the gongs operated. When the p inter is r set. the transmitter continues to operate until it com letes one ha f revolution. The master cam of the transmitter is cut in such a wav t at ts contacts will resume their normal cond tion after the transmission of the restoration s gnal so that only one recording is obtained.

Waterflow tamper signals If someone opens the transmitter housing 2 ID, the tamper switch is moved to contact 214' by any suitable means for instance a sprin 2| I when the housing releases the vertical rod 2 l2 pivoted to an extension of the switch transfer element. This causes a distinctive tamper signal. In that case the starting circuit can be traced from the ST line through contact 2I0,-the normally open contact 2i4' of the tamper switch, contact 2| l, and the right hand motor winding to line 0.

As the transmitter starts w th the thermostat in its normal condition, the 1atch operated by the thermostat in case of waterfiow is not in position to engage pen spring 253. After cam 254 has been rotated slightly,-pen spring 253 drops off the tooth and closes the associated contacts. It will be noticed that the contacts of cam 255 are thereby connected in multiple w th the coding contacts. The tooth of cam 255 is so arranged that the associated contacts are closed for one step at the time the main coding contacts are closed for one step at the time the main coding contacts are opened at the end of the first digit of the code. An additional high current impulse is thus transmitted. r

This causes the first typewheel of the printer to be advanced to the fourth position bringing WF tamper into printing position. The rest of the operation is the same as for waterfiow alarm signals. Relay 350 and the go ngs are not operated as cam operated contact 501 (Fig. 5) is open in position 4 of the first typewheel.

Waterfloio tamper restoration When the tamper contacts are restored to the normally closed position, the transmitter is started as for waterfiow restoration signals. However, the additional impulse will also be added at the end of the first digit again causing the designation WF tamper to be recorded on the printer, otherwise the recording is as explained above for waterflow restoration signal.

ALARM SIGNAL PRECEDENCE AND NON-INTERFERENCE AND SUCCESSION BETWEEN ALARM AND Sunn- VISORY CIRCUIT If an alarm transmitter is actuated at or about the same time as a. transmitter connected to the supervisory circuit, it will take precedence over it. In this case both relays H6 and H6, which may here be called precedence relays, will be energized. The operation of the pulsing relays will be started with relay 304 pulling up, then relay 305 and then relay 304 releasing. A circuit is now closed from plus through contacts 3 I2, 3l3. of relays 305 and 304, respectively, conductor 3 I4, contact 223 of relay 2H3, conductor 224 and through the coil of alarm master relay H5 and back contact MS of relay (M5 to minus. Supervisory master relay 3|5 cannot operate as contact 222 of relay 216, which supplies plus to contact I23 of relay H6 over conductor 3I4, is open.

If a transmitter on the supervisory circuit is actuated first, it has to complete its signal in order to prevent interference but will let the alarm signal get in immediately after operating the printer. Assuming that while a transmitter is operating on the supervisory circuit, an alarm transmitter is actuated. relays 203 and 2; will be operated but relay 3l5 cannot be energized immediately as back contact 3l6 of relay 3l5 is open. When, however, relay 3I5 releases at the time of the printing operation, this contact closes again and relay 3I5 will operate as soon as the pulsing relays have started up and contact 3l2 of relay 305 closes. In this case the transmitter operated first on the supervisory circuit will not complete its cycle until after all alarm signals have been cleared. It will then complete its remaining steps bringing the master cam back to the home position. This latter operation has been explained above in connection with the description of the supervisory transmitter.

Non-interference and succession of transmitters on the same circuit In case several transmitters are actuated on the same circuit at or about the same time they will be energized for the initial starting impulse for which current is derived from the ST line. When 315 or 3l5' operate, the starting line will be simultaneously deenergized by the opening of back contact 30I or 30! respectively; and the transmitters operate their master cam contacts to the running position. It will be seen that the transmtter located nearest to the out" side of the R line will be the only one to receive line impulses over the running line. After transmitting its signal and returning to the home position, this transmitter restores the running line to its normal condition and impulses will now be directed to the second transmitter which again prevents impulses from reaching transmitters waiting further back on the line.

In case of this happening on the alarm circuit, the transmitters waiting will come in successively one after another without relay 315 releasing between. It has, however, been pointed out that the converting relays 4| I and 412 are arranged to always complete a full cycle for each type of transmitter signal so as to be ready for a new counting cycle when a new transmitter starts to transmit.

Automatic trouble adjusting means and operation under trouble conditions In case of a break on the ST or C line, the corresponding relay I 02 or 202 is deenergized and closes a circuit for the trouble lamp I01. Assuming that the break occurs on the supervisory circuit, for instance, the release of relay I02 or IN or both, causes the deenergization of the normally energized upper Winding of adjusting relay I25. Relay I25 releases and cannot be reoperated through this winding as contact I26 opens. This relav closes a circuit to the alarm buzzer 348 (right of Fig. 3) over conductor 360 by closing its back contact I36 (lower part of Fig. 1). The buzzer can be silenced by the operationof the corresponding silencing switch I36.

In this connection it may be pointed out that in case of operation with the circuit at normal, relays I02 and I! are also deenergized when the circuit of the starting and running line is interrupted by relays H6 and 3I5. However, relay I25 is held energized as a multiple circuit is closed by contacts I28 of relay I03 and I29 of relay H6, also by contact 36I of relay 3I5 over conductor I30, keeping relay I25 energized during the transmission of the signal. After the release of relays I03, H6 and 3I5, relays I02 and I0! pick up again, closing the normal circuit for relay I 25. As there is a slight interval of time between the restoration of the line circuits and the closing of the make contacts of relays I02 and I01, relay I25 is equipped with a copper slug in order to keep it energized during this interval. The arrangement for the alarm circuit is identical.

Relay I25 releasing in case of a break of a line conductor connects the two ends of the ST lines together and the two ends of the C lines together, respectively by contacts I3I and I32 so that plus and minus polarity respectively is fed to both ends of the respective circuits at the same time. Assuming now that a break in all three wires is the case of the trouble, which is the most severe condition, all transmitters connected to the circuit will still be able to obtain plus and minus polarity over the ST and C lines respectively for the initial starting step when actuated. A transmitter located between the break in the R line and its out side will operate in the usual way starting the operation of the system by operating relays I03 and H6. If, however, the transmitter is located between the break and the "in side of the R line, the closing of the armature contact will not operate starting relay I 03 but operates relay IIB directly through the in side of the R line, contact I33, the right hand winding of H6, contact I34 and the left hand winding of H6 to plus. Relay H6 operates and closes the holding circuit for its left hand winding through contact H8, resistor II9, over holding conductor H and through contact 303 to minus. As contacts I34 and H8 are of the make-before? break type. the circuit of relay H6 is never interrupted. Relay II6 starts the operation of the pulsing relays in the usual way. It will be seen, however, that impulses are now transmitted through back contact I35, the right hand winding of relay II 6 and back contact I 33 over the in side of the R line, through the master cam contact I28 of the transmittenits left hand magnet coll and through the C line to minus. This magnet is capable of operating the transmitter in the same way as the right hand one. Otherwise, however, the operation is the same as under normal conditions. The right hand winding of relay I I6 is similarly arranged as the left hand winding of I03 to hold relay II6 energized during the transmission of impulses. The left hand winding of H6, similarly as to the right hand winding of I03 is deprived of current during the time of impulse transmission due to contacts 303 of relay 3I5, 323 of relay 305 and 324 of relay 304 being open. This arrangement again serves the purpose of clearing the control center equipment when the transmitter gets ofi the line.

Non-interference and succession on a circuit with line troubles The non-interference and successive operation is not affected by breaks in the ST and C lines. In case of a break in the R line, transmitters operated simultaneously between the break and the "out" side of the R line will operate in the standard way. In case of transmitters operated simultaneously between the break and the in side of the R line, the one nearest to the "in side will transmit its signal, first operating the relay H6 or relay 2I'6 directly as explained above. Otherwise the operation is the same as for normal conditions.

Simultaneous operation of transmitters on opposite sides of a break in the R line If two or more transmitters are simultaneously actuated, for starting, on opposite sides of a break in the R line, the transmitters located between the break and the out" side of the R line will operate the I03 relay and I I6 relay in succession. Transmitters located between the break and the "in side of the R line will directly operate the II6 relay as explained before. As the H6 relay breaks the operating circuit of the I03 relay by its contacts I04, the I03 relay may not have a chance to pick up if the transmitters are operated at exactly the same time. In that case, impulses will first be transmitted over the in side of the R line through back contact I35 of relay I 03. After all the transmitters connected to that side of the circuit have transmitted their signal and the relay I I6 is deenergized, relay I 03 will be energized in series with the right hand coil of the transmitter nearest to the out side of the circuit. Relay I03 operates relay I I6 which starts the operation. The transmitters located between the break and the out side of the circuit will then transmit their signals in succession. The same applies, of course, to re'lays 203 and H6 of the alarm circuit.

Restoration of circuit to normal after remedying trouble condition When the line breaks have been repaired, relays I02 and I0! or 202 and 201, respectively, will, nevertheless, not pick up since relay I25 or 225 first has to restore the line circuit to its normal condition. These relays are provided with another windlng (th lower ones). These windings are connected to the minute impulse contact over conductor 36I and are energized once every minute. The next minute impulse following the repair of the line circuit will cause the corresponding relay I25 or 225 to pick up. It will then lock in through its contact I26 or 226, respectively, as

5 soon as the relays I02 and I0! or 202 and 201 pick up. At the end oftheuaminute impulse,;relay I25 or 225 will then stay. energized leaving the circuit at normal.

When relay I25 or225' operates, a circuit is closed for the buzzer through make contact I21 or 221 and the normally open side of the associated silencing switch which previously has been operated. By throwing the switch back to normal, the buzzer can be silenced. Relays I02 and I01 or 202 and 201 when operated, extinguish the lamp which was lighted when theyreleased.

As a time impulse may come in during the transmission of a signal on an abnormal circuit, it must be prevented from causing interference by energizing the corresponding relay- I25 or 225. This is obtained by connecting the restoring winding of these relays in series with a normally closed contact I31 or 231 respectively of the relay H6 or 2; respectively which contact will then be open.

From the above it will be clear that, if a transmitter starts after the line has been repaired but before the minute impulse has restored relays I25 or 225 respectively, the'signal will nevertheless be received without fail. 1

Ground supervision and operation with grounded lines The system is operated froman ungrounded battery. However, the center of the battery is connected through contacts 363, 363 and the coil of relay 362 to ground. If a ground occurs on any of the line wires, this relay will be operated and closinr. its contact 364 light a lamp. By closing its make contact 365, the buzzer 348 is operated. It can be silenced by operation of the associated silencing switch. Operation of the system with a single ground on the line wires does not interfere with the normal operation as the only other ground is through the very high resistance of relay 362. In addition this ground is removed as soon as relay 3I5 or 3I5 operates which then only leaves the accidental ground as the only one on the system. It will then have no effect at all.

If a ground occurs on two line wires simultaneously, it amounts to a short circuit between line Wires and in most cases the line fuses will be blown except a ground on both the C line of t e alarm and that of the supervisory circuit which will not interfere with the operation.

Automatic clearing aft r disarrangement of equipment If in working on the relays etc. the service-man should accidentally operate any of the relays, they will not lock in, as all locking circuits are arranged to function duringv operation only. Such accidental operation will, therefore, not affect a succeeding signal. Only the special alarm relay 343 can lock itself, but this is made noticeable immediately by the audible and visual signals and furthermore has no effect on succeeding signals. It can. of course, be restored in the usual way by operation of the acknowledgment key.

If the printer stepping magnets are manually operated, while the equipment is idle, relay 432 will be immediately energized from minus through the printer latch contact L, which will then be closed, over conductor 4I I, through contact 368 and 368 over conductor 310 and through the right hand winding of relay 432 to plus. This causes the operation of the printer release magnet RL through the same circuit as traced before. The release magnet restores all of the printer opens the latch contact. The latter causes relay 432 to release again. It is therefore impossible to leave any part of the equipment in a condition that it will interfere with the proper reception of a subsequent signal.

Various modifications of the embodiment of the invention specifically described above will occur to those skilled in the art and may be made without departing from the scope of the invention as set forth in the appended claims.

I claim:

1. In combination, primary and secondary groups of transmitters, a single receiver, means for initiating the starting operation of each transmitter, lines connecting the respective groups with the receiver, means associated with the lines, groups, and receiver whereby a transmitter from either group may operate the receiver, and means for establishing precedence of connection to the receiver for all of the transmitters of the primary group over the transmitters of the secondary group regardless of the order in which starting operation of the transmitters is initiated whereby a transmitter of the secondary group can be connected to the receiver only when no transmitter of the primary group has its starting operation initiated.

2. In combination, primary and secondary groups of transmitters; means for initiating the starting operation of each transmitter; means for preventing the signaling of a transmitter of the secondary group when the starting operation of any transmitter of the primary group has been initiated, and means for interrupting signaling by a transmitter of the secondary group at a predetermined point in its signaling cycle following the initiation of the starting operation of any transmitter of the primary group.

3. In combination, primary and secondary groups of transmitters, means for starting each wheels to normal and transmitter; means for preventing the signaling of a transmitter in one group when a transmitter in the other group is signaling; means for preventing the commencement of signaling of a transmitter in the secondary group when the starting means of any transmitter in the primary group has already been operated, and means for interrupting signaling by a transmitter of the secondary group at a predetermined point in its signaling cycle following the initiation of the starting operation of any transmitter of the primary group.

4. In combination. at least two transmitters for sending signals of different classes, precedence relays set in operation by operation of the respective transmitters, master relays for the respective transmitters, switching means for energizing one master relay only when its precedence relay is energized and the other master relay is deenergized, and means for energizing the other master relay only when its precedence relay is energized and the first master and precedence relays are deenergized, means set in operation by either master relay when energized for rendering the associated transmitter operative, and means for interrupting signaling by a transmitter of signals of lower class at a predetermined point in its signaling cycle following the initiation of the starting operation of a transmitter of signals of higher class.

5. In a signaling system, a supervisory circuit including a plurality of motor driven supervisory transmitters, an alarm circuit including a plurality of motor driven alarm transmitters, each of the above circuits including a means for starting each transmitter, a precedence relay associated with each circuit and energized in response to the transmitter starting means, a source of impulses common to the alarm and supervisory circuits, means responsive to the precedence relay of each circuit for starting the source, a master supervisory relay, a master alarm relay, mutual control circuits operated by the master relays whereby only one can be energized at a time, a circuit controlled by the alarm precedence relay for actuating the master supervisory relay whereby the master supervisory relay is disabled if the alarm circuit is active, means for disabling the master supervisory relay at a predetermined point in the signaling cycle of a supervisory transmitter following the initiation of starting operation of an alarm transmitter a driving circuit connected to the supervisory circuit established by the master supervisory relay, a driving circuit connected to the alarm circuit established by the master alarm relay, switching means operated by the source for sending an operating pulse through the driving circuit to the motor of the operating transmitter in either the alarm circuit or the supervisory circuit.

6. In a signaling system, a supervisor circuit including a plurality of supervisory transmitters, an alarm circuit including a plurality of alarm transmitters, each of the above circuits including a means for starting each transmitter for increasing the current in circuit, a starting relay in each circuit actuated by the current increase, a precedence relay associated with each circuit and energized by the starting relay, a source of impulses common to the alarm and supervisory circuits, a circuit to the source closed by the precedence relay of each circuit for starting the source, a master supervisory relay, a master alarm relay, mutual control circuits operated by the master relays whereby only one can be energized at a time, a circuit controlled by the source and the alarm precedence relay for actuating the master supervisory relay whereby the master supervisory relay is disabled if the alarm circuit is active, means for disabling the master supervisory relay at a predetermined point in the signaling cycle of a supervisory transmitter following the initiation of starting operation of an alarm transmitter a driving circuit connected to the supervisory circuit established by the master supervisory relay, a driving circuit connected to the alarm circuit established by the master alarm relay and switching means operated by the source for sending an operating pulse through the driving circuit to the operating transmitter in either the alarm circuit or the supervisory circuit.

7. In a signaling system, a supervisory circuit including a plurality of supervisory transmitters, an alarm circuit including a plurality of alarm transmitters, each transmitter including a motor coil, each of the above circuits including a common line and a running loop connected to each transmitter, a switch operated by the motor coil of each transmitter for connecting the running line to the common line to increase the current in the running line, a starting relay in each circuit actuated by the current increase, a precedence relay associated with eachcircuit and energized by the starting relay, a source of impulses common to the alarm and supervisory circuits, a circuit to the source of impulses closed by the precedence relay of each circuit for starting the source, a master supervisory relay, a master alarm relay, mutual control circuits operated by the master relays whereby only one can be energized at a time, a circuit controlled by a source of impulses and the alarm precedence relay for actuating the master supervisory relay whereby the master supervisory relay is disabled if the alarm circuit is active, means for disabling the master supervisory relay at a predetermined point in the signaling cycle of a supervisory transmitter following the initiation of starting operation of an alarm transmitter a driving circuit connected to the running line of the supervisory circuit established by the master supervisory relay, a driving circuit connected to the running line of thealarm circuit established by the master alarm relay and switching means operated by the source of impulses for sending an operating pulse through the driving circuit to the motor of the operating transmitter in either the alarm circuit or the supervisory circuit.

8. In a signaling system, a supervisory circuit including a plurality of supervisory transmitters, an alarm circuit including a plurality of alarm transmitters, each transmitter including a motor coil, each of the above circuits including a common line and a running loop connected to each transmitter, a switch operated by the motor coil of each transmitter for connecting the running line to the common line to increase the current in the running line, a starting relay in the running line of each circuit actuated by the current increase, a precedence relay associated with each circuit and energized by a contact of the starting relay, a pair of mutually controlled pulsing relays common to the alarm and supervisory circuits, a circuit to one of said pulsing relays closed by the precedence relay of each circuit for starting alternate operation of the pulsing relays, a master supervisory relay, a master alarm relay, mutual control circuits operated by the master relays whereby only one can be energized at a time, a circuit controlled by a contact of the second pulsing relay and the alarm precedence relay for actuating the master supervisor relay whereby the master supervisory relay is disabled if the alarm circuit is active, means for disabling the master supervisory relay at a predetermined point in the signaling cycle of a supervisory transmitter following the initiation of starting operation of an alarm transmitter a driving circuit connected to therunning line of the supervisory circuit established by the master supervisory relay, a driving circuit connected to the running line of the alarm circuit established by the master alarm relay and switching means operated by the first pulsing relay for sending an operating pulse through the driving circuits to the motor of the operating transmitter in either the alarm circuit or the supervisory circuit.

MANFRED W. MUEH'I'ER.

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