US2375238A

US2375238A - Transmitter

Info

Publication number: US2375238A
Application number: US439985A
Authority: US
Inventors: Manfred W Muehter
Original assignee: American District Telegraph Co
Current assignee: American District Telegraph Co
Priority date: 1938-01-12
Filing date: 1942-04-22
Publication date: 1945-05-08
Anticipated expiration: 1962-05-08

Description

May 8, 1945. M. w. MUEHTER TRANSMITTER Original Filed Jan. l2

IIIIIT! 4mm-IS mDOU mm, mm

lNVENTOR M. W MUE BY a Q HTER if,

ATTORNEY Patented May 8, 1945 TRANSMITTER M'nehtelr, Nutley; N. J.,V assignor to @American District, Telegraph Company, Jersey GityN.J-.a corporation of New Jersey applfcatmnjancsry 12, 193s, serial No. l8,595. .Dividedf and this' application April 22.

wie, No. 43o-,985

15 Claims.

This inventionreiates tou-ansmlttersior alarin systeme-'anc :here to rs of the code-4 wheer type current The 'furthrrelats lio-:a iodiilcationor immovement for the: transml 'apparatus' dlsclsedfi'n applicant's prior No. 2,109,273, Februar-22,- l15938; application being a givlslm :mi apuessgsf'moreeent No, zonared; 2;' msg' ppncsnon scrl-Registres;@mee'ms'izfressg' 'I'liejobjeot o! theflnventinis t6 improve the Conslirnotfoiid V'tion of abode than desem 86V f' y ST5-u fi.

Another oliictofthe is to provide transmitting'l ofthe wli'ecltype which wm eccessive esfgseneme dansent signals at difierenvtmres-or uni-ler 'conditions.- object 'of' invention is to provide a unitary will' transmit onefslgnal'ioreeies oi' 1current*impulses'when the assoclatediiapparatus such' as a 'water tlow detect'or is rendered operative, and transmit a different "signal Ion' series o! current impulses from thesame code' generutingfelementsim casethe associated device or water' now?- detector is tampered Another object of the invention is to provide, in connection w'lth 'a for su the operation `ot a valve' tar-'otherl device, improved means for indicating or signalingthnfact that theslmervisory been deranged or' tampered with, preferably at a. remote super vison' station.

Another objectsofthe invention is to provide improved means for transmitting supervisory or alarm :md4 restoration signalsV when the device supervised operates (or is operated) and when it is4 restored to normal, respectively.

A. still further obt of the invention is to provide an improved arrangement for delaying the operaon of signaling means where, as in the case of water ow supervisory appltus, the operation is. likely to. be impz'pell7 initiated by a momentary unpulse such as a Water surge in the pipe line.

Gther objects and advantages of' the invention will appear from the following description of the preferredemhodiment thereof shown in the accompanying drawingl wherein:

Fig. 1 is a1 diagrammatic view of a transmitter and supervisory system embodying the invention, the controlling and recording apparatus being only shown in suiilcient detail to render the operation of the transmitter clear; and

lll)

Figs. 2 to 4, inclusive, are graphs representing the signals sent by the transmitter under assumed conditions. Y

Referring to Fig. l of the drawingja. water-now transmitter 'is illustrated which4 is' arristngelzl for thetransmission of repeated alarm signals to *a printer or other receiver at the 'central ofllce'upoi the operation' of a water-now switch in asprlhkler system. The transmitter' show-n is one otisevril at different points along the loop circult'frrn the central oillce, said circuit comprising the starting, running' and common conductors "j, 'as indicated. The system features, 'including opration of several transmitters on a. com'nin loop circuit, the supervision of the circuit wires 4and the 4central station control-' and recording equipment, are 'covered in the 'above-mentioned Patent No. 2,309,660; 'of which the present applicationis a division, and also in my copending' application Serial No. 350,622, filed August 3', '1940; which is also a 1cllvislonof said patent.

The water-flow transmitter shown comprises a code wheel i5 having peripheral teeth correspondlng to an alarm code on one half of? the wheel and a restoration code on the other half; The code wheel I5 is mounted upon 'a main shaft adapted to be actuated by the armature I6 of electromagnets I l and Ill, the main shaft-also carrying cams I9 and 2U. The transmitter further comprises a second shaft gearedk to said main shaft and carrying the cams 2| and' 22g-said geared shaft being arranged, for instance,

make one revolution for every two revolutlons'of the main shaft. Since water-now signalsA are sent during one and one-half revolutions of the code wheel and a restoration signal during oxiei half revolution of the code wheel, the cam 2'# operates the master switch at 270 and 366 from normal, as shown.

The transmitter shown for the purpose of illustrating the invention is dn'ven by current impulses irom the central station. The impulses transmitted are converted by the code wheel into strong and weak impulses, respectively, weak impulses representing spaces in the code, The code impulses are arranged to operate a. printer 25 at the central oiice` or any suitable code responsive mechanism connected to the marginal coding relay 26 which is operated by the strongcode impulses. f

The operation of the transmitter to send .an alarm signal is'initiated by the operation of the water-now switch to the position in which the contacts 2l are closed. In the present instance, it is assumed that the closure of these contacts is effected by means which is responsive to the flow of water in a sprinkler system. Obviously, the contacts arranged to initiate the operation of the transmitter may be closed manually or automatically in response to any condition which it is desired to indicate or record at a remote station. Likewise;v the transmitter shown may'also be initiated in operation by the closure of the contacts 2B of the tamper switch, these contacts being biased, for example, by a spring 29 to close when the cover of the water-flow switch is removed, or in response to tampering of the switch in any other desired manner. The operation of the tamper switch contacts 28 initiates the operation of the code transmitter, but in this instance a different code is transmitted, `the code wheel I5 being employed for both the alarm and tampered codes. When both of the switches 21 and 28 have been restored from their operated position to normal, the code transmitter is again operated to send restoration codes in a manner that will be hereinafter described.

In the event that the flow detector operates the water-now switch, the water-flow alarm code is transmitted as follows: Upon the closure of the contacts 21, a circuit is closed from'positive battery ythrough the contact lof relay 3|, the ST conductor, the alarm contact32 of the transfer cam 20, lthe contacts 21, the heating coil 35 of thethermostat 35, and the common conductor C to negative battery at the central station. The thermostat 35 starts to heat up but is not oper.- ated unless the water-dow contacts remain closed. In this manner the operation of the transmitter is prevented in case of a momentary closure of the contacts 21 owing to water hammer in the piping system. thus eliminating false alarms that would be caused by surges in the water pipes. In case the water ilow maintains the contacts 21 closed, the. thermostat bar 36 finally closes a circuit through contact 40 and connects the positive batterr on the starting line through said conta/ct and contact 4I of the master switch to the right hand magnet coil I8, which-is also connected to nega.- tive battery on the common line C. The thermostat bar 35 is also arranged to latch the contacts controlled by the cam 22 in the normal position, as shown. The magnet I8 becomes energized and attracts its armature I6, thereby retracting the operating pawl into engagement with the next tooth on the main shaft and closing a. circuit from the tap on the magnet coil IB through the arma ture I5 and contact 42, contacts 43 of the master switch, the running conductor R and the outer windings of relay to positive battery. The relayv 45 is provided with two windings in series with the outgoing line R and a third winding in series with the in running line R as shown. This relay is provided for the purpose of supervising the running line conductors, being normally deenergized by the opposed windings connected in series with the ends of the running line loop, as explained more fully in my above-mentioned Patent No. 2,309,660. However, when the contacts 42 of the motor magnet of the transmitter connect negative battery to the left hand and right hand windings of the relay `45 in series with the low-resistance portion of the winding of the magnet IB, as described above, relay 45 becomes effectively energized and attracts its armatures. The closure of the armatures of relay 45.connects battery to the impulse starting conductor 41 to initiate the operation of the pulsing relays 48.

The pulsing relays 48 include separate contacts 49, 5I) which are closed in properly timed relation to control the energzation of relay 3l which operates before the pulsing by contact 5I) starts, and

to transmit impulses through the winding of the coding relay 26, contact 5I of relay 3|. contact 52 i of relay 45, the left hand winding of relay 45 to the running conductor R of the loop circuit. When the motor magnet I8 becomes deenergized due to operation of relay 3 I the main shaft of the transmitter is stepped one step and the cam 2| operates the master switch so that the running circuit is transferred through the contact 54 of the master switch to the winding of the motor` magnet IB. It will be understood that the motor magnet I1 is connected in a similar way to the opposite running conductor of the loop to provide McCullough operation. At the end of three alarm codes transmitted by one and one-half revolutions of the main shaft, the transfer cam 42l of the motor magnets l1 and I8 so that the current owing in the running circuit is increased. The strong current impulses traversing the coil of the marginal coding'relay 2B close the contacts thereof and operate the ,associated printer or code-responsive mechanism 25.

The code wheel i5 1s provided with teeth on one half of its periphery corresponding to the alarm code, as stated above, and on the other half with the restoration code. It may be assumed, for example, that the rst digit of the alarm code consists of three teeth followed by two spaces, as shown in Fig. 2, and the restoration code consists of the similar grouping of teeth except that the second tooth of the rst digit is missing, as shown in Fig. 3. Since the code wheel l5 rotates one and one-half revolutions to send three water-flow alarm signals, the second line impulse of the second code is normally of low current intensity, as in the restoration code. Since this code immediately follows one alarm code group, it will be recognized by its time of occurrence as a waterflow alarm signal. If desired, means such as that described in my parent application may be provided at the central station for converting the code into an alarm code so that the printer 25 will print three water-:low alarm signals before the transmitter stops.

After one and one-half revolutions of the main shaft for sending the three alarm codes as described, the transfer cam 20 is in a position displaced from that shown in Fig. l. ingly. a circuit will be closed through the restoration contact 51 associated with the transfer cam Accord- 2B for restarting the transmitter when the waterl flow switch is restored and connects the starting conductor through contact 51, the normally closed contacts' of the water-flow switch and tamper switch and the contact 4I of the master switch to magnet I3. The transmitter operates as described above for one-half a revolution of the main shaft. In this manner the restoration code is transmitted when the water-flow switch returns to normal. the transmitter being stopped by the opening of the contact 54 o f the master switch after one restoration code has been transmitted.

The cent-acts 28 of the tamper switch are arranged to be closed, for example. by the spring 29. when the cover of the water-flow switch is removed as described above, or in response to-any other predetermined tampering with the switch. When the contacts 28 are closed in: this manner, the smztlng circuit of the marmitte: isl connected through contact.L 32 assoeated' "with the transfer com 2c, the; contracts 28 of the tamperA switch and: the contact il ot the master' switch to start the' transmitter in the same manner as'4 desmibed above' inconnection With'- the operation o! the. Water-flow switch. In this ease, however, the contacts 59 associated' with the carri 22 arev not locked. open by the thermostatlbaror'latchf 36: andthusare closed as soon as the ttor* is started. The closure of the' contacts 5s connects theeontacts so associated rwibhitl'ie lcanrilin circuit with the highl 'resistalnce windn'gsll'ol' the` motor mag-nets l1 and iii;- AAccordingly;f when the contacts 3U are. clod by the 'com fs', anadditlonal strong current impulse is added to the code represented by' the' offthecode wheels F5. Thus, as shown in Fig. 4,? thetamper-eode 'alarm signal may be similar iid-the water-iibwalarm signal' of Flg.f2`fexcept thatftliflirst digit consists of four impulses instead of three, by proper location oi of thev cas'm' W. likewise, when the tamper switch is restored'to normal*,opening the contacts, the tamper restoration code is transmitte'd, 4which maybe aco'cle" similar-',mthe w'il'tefflow restoration code shown inA Fig'. 3 except'that the fourth impulse s a strongcurrent of a weak' current impulse. In ti'iisnalner 'dl'ereit codes aref transmitted by the 'transmitter for water-now alarm and for tamper signals by employing the earn |59 under thev controlfofthe contacts 59 to addome orv more Supplemental 'lihptiises Iiorrnally trans mitted by theteeth in tire'v code wheel l5.

v'I 'he r4alarm signal transmitted and also the lesV :ill

restoration signal transmitted 'depends for its character' on which of the switches `2i or 2'8 is first operated. Flor example, if switch 21' moved tov alarm position andlmaintalned'ln that position long enough for' tHe-thermostat bar 3s to. complete its latch action closing qcontact do. a. water-now alarm signal wlll be transmitted and even 'though the switch ,28 be subsequently moved to alarm position, such movement will not result in the transmission of a. tamper alarm signal due to the fact that the alarm initiating circuit closed by the contacts 32 is open once the transmitter operation has begon (by action of. relay 3l in breaking contact-30). Should both switches 21 and 28 operate in almost simultaneons fashion, the signal transmittedjwill depenr: entirely on Whether the contact All. has been closed and the mechanical latch afforded by bar 36 has been completed. Il such latching of the contacts to maintain contact 40 closed has not been accomplished, then the signal transmitted will be a tamper alarm signal. Likewise, once an alarm signal of either character has been transmitted, the restoration signal which will be transmitted in the second part of the divided cycle of transmission will be the restoration signal` corresponding to the alarm signal. For example, should the alarm signal be initiated by the switch 21. and should the switch 28 be subsequently operated to alarm-position as before stated the alarm Signal will be a. waterA ow alarm. But should the switch 21 be moved to restoration position followed by restoration of switch 28. still the restoration signal will be for the water-dow indication' since contact 4D has been maintained in locked position until the lobe of cam 22 is restored to its starting position relieving the pressure on bar 3G suiciently to permit unlatching of contacts 40. Likewise should. the alarm have been initiated. byl switch 28 and the alarm signal for that condition transmitted. even though switch 2l is subsequently operated and then returned to normal prior to restoration of switch 28, the restoration signal will be that associated with switch 28 since under these conditions it'. would' have been impossible t-o close switch 48 and maintain the latch in closed position. It is evident,- of course, that both switches' 2'! and. 28 must be in normal positionA before the' proper restoration signal can be transmitted. From: the' foregoing it will be seen that transmission occurs in two parts of a divided cycle and the system' is so constructed that conditions established at the initiation of transmission are maintained for both parts of the cycle or; in other words'. for a f uli cycle of transmission; with the result that the character of signals cannot be varied to indicate different conditions during a. full cycle of transmission.

Various modications. in the transmitter shown and desrrbed for the purpose of explaining the invention will occur to thoseV skilled in the. art and? may be made without departing from the scope of the invention: as defined in the appended claims.

I claim-z l2. In` combination, a code wheel current-impulse transmitting means for transmitting different signals during each division of a divided cycle of operation, the signals transmitted in the divisions of said cycle of operation' being irlclicative of dilerent conditions of the control means of said transmitting means, control means for initiating operation of said transmitting wenns, second control means l'or initiating operation oi said! transmitting means and for modifying said signals to cause the operation of :heV transmitting means to transmit different signals and means for preventing modification of the character of signals being transmitted during a complete cycle ol operation of said transmitting means.

2. ln combination, transmitting means iucludinp` a code wheel having a. series of teeth to transmit a predetermined different code during each division of a divided cycle of operation, the signals transmitted in the divisions of said cycle of operation being indicative of dilerent conditions of the control means for said transmitting means,A control means lor initiating operation of said transmitting means, second control means for initiating operation of said transmitting means and for modifying the code transmitted thereby, and means for rendering either cf said control means inoperative to initiate operation of said transmitting means prior to the completion of a full cycle of operation thereof initiated by the other control means.

3. A transmitter comprising a main code transmitting means adapted to transmit predetenninecl different signals during each division of aA divided cycle of transmission, said divisions of a divided cycle being indicative of different conditions of the transmitting means control means, a supplementary code transmitting means operatively associated with the first-mentionen transmitting means, control means fol' rendering said first-mentioned transmitting means operative independently of the supplementnry code transmitting means to transmit signals, control means for rendering both of said rode transmitting means operative at the same time to create modified different signals during each of said divisions of said divided cycle of transmitting-means operation, and means positively maintaining a selected transmitting condition during a complete cycle of transmitting means operation.

4. A transmitter comprising a main code transmitting means adapted for transmitting predetermined different signals during each division of a. divided cycle of transmitting means operation, said divisions of a divided cycle being indicative of diierent conditions of the transmitter initiating means, a supplementarycode transmitting means for altering said signals tocreate diierent signals during each division of said divided cycle, an initiating means for operating the main code means, a second initiating means to render the main code and supplementary means operative to transmit altered diierent signals during each division oi said divided cycle. and means for rendering either of said initiating means inoperative to initiate operation of the transmitting means prior to the completion of a full cycle of transmitting means operation initiated by the other of said initiating means.

5. A transmitter comprising code transmitting means for transmitting predetermined main signals during each part of a. divided cycle of transmitter operation, means for modifying the signals transmitted during each part of a divided cycle of transmitter operation, .the signals transmitted in the parts of a divided cycle of transmitter operation being indicative of diierent ccnditions of the control means for said transmitting means and mainand second control means movable selectively to initiate operation of the transmitting means to transmit main and modied signals respectively during therstpart of said divided cycle, each of said control means being operable when restored to normal position to cause operation of said transmitting means to complete the signalling cycle thereof, said control means being so related that transmission of signals initiated by one thereof prevents initiation of signal transmission by the other thereof prior to the completion of the initiated full cycle of signal transmission.

6. A transmitter comprising code transmitting means for transmitting predetermined main signals during each part of a divided cycle of transmitter operation, means for modifying the signals transmitted during each part of a divided cycle of transmitter operation, the signals transmitted in the parts of a divided cycle of transmitter operation being indicative of different conditions of the control means for said transmitting means and main and second control means movable selectively to initiate operation of the transmitting means to transmit main and modified signals respectively during the first part of said divided cycle, each of said control means being operable when restored to normal position to cause operation of said transmitting means to complete the signalling cycle thereof, said control means being so related that transmission of signais initiated by one thereof prevents initiation of signal transmission by the other thereof prior to the completion of the initiated full cycle of signal transmission, said control means being so related that the second part of a cycle of signalling can be initiated only when both of said control means are in their normal positions.

7. A transmitter comprising a main code means for transmitting signals, a second code means adapted to add to said signals, main signal initiating means, a second signal initiating means for starting the main code means, a device set in operation by the main signalinitiatng means for operating the main code means, and means to render said second code means operative when the device means is not operated.

8. A transmitter comprising a pair of lines, a motor, main and second code transmitting means operated by the motor, the main code means adapted for predetermined signals, the second code means adapted to add to said signals to form second predetermined signals, a heater connected to one line, a normally open starting switch connected between the other line and the heater, a thermostat switch element adapted when flexed by the heater to connect said motor between the lines and means controlled by the thermostat to render said second code means capable of operation.

9. A transmitter for transmitting signals differing from one another in their characteristics comprising a motor, a Code transmitting switch driven thereby and including a wheel having a1- ternate sets of teeth, and contacts operated thereby for transmitting first signals followed by second signals, an operating circuit for energizing the motor including a line, a Vmain control switch having .a normally closed contact and a normally open contact, a secondary control switch having a normally closed contact and a normally open contact, means associated with said secondary control switch for modifying said first and second signals, a cam operated transfer switch driven by the motor connected to the line for successively establishing connections from the line to the normally open contacts and the normally closed contacts, a thermostatic auxiliary switchconnected to the normally open contact of the main control switch adapted to close its contacts after a certian period of current ow, a cam operated master switch driven by the motor and having certain normally closed contacts connected to themain control switch and the secondary control switch for completing a starting connection to the motor when the normally open contact of one of the control switches is closed while the other thereof is in normal position, and other contacts operated by the cam for connecting the code contacts to a transmission line for code transmission until the code wheel has completed'an odd number of half revolutions to thereby transmit a rst signal and for subsequently connecting the code contacts to the transmission line until the code wheel has completed another half revolution to transmit a second signal in response to the restoration of the abnormal control switch to normal position.

l0. A transmitter for transmitting signals diftering from one another in their characteristics comprising a motor, a code transmitting switch driven thereby and including a wheel having alternate sets of teeth and contacts operated thereby for transmitting first signals followed by second signals, an operating circuit including a line, a main control switch having normal and abnormal positions, a secondary control switch having normal and abnormal positions, means associated with said secondary control switch for modifying said first and second signals, a cam operated transfer switch driven by the motor and connected to the line for successively preparing circuits which can be completed by the control switches for initiating transmission of iirst or second signals, a thermostatic auxiliary switch connected to the abnormal position of the main switch and adapted to delay the effect of operation of this switch whereby false signals are prevented, and a motor driven master switch for completing a starting connection to the motor when one of the control switches is moved to abnormal position while the other is in normal position and for connecting the code contactsto a transmission line to' thereby transmit a rst signal of character determined by the abnormal control switch and for subsequently connecting the code contacts to the transmission line to transmit a second signal in response to actuation of the abnormal switch to normal position.

11. A transmitter for transmitting signals differing from one another in their characteristics comprising a motor, a code transmitting switch driven thereby and including a wheel having a1'- ternate sets of teeth and contacts operated thereby for transmitting first signals followed by second signals, an operating circuit including a line, a iirst switch having a normally closed contact and a normally open contact, a second control switch having a normally closed contact and a normally open contact, means associated with said second control switch for modifying said first and second signals, a cam operated transfer switch driven by the motor and connected to the line for successively establishing connections from the line to the normally open contacts and the normally closed contacts, and a cam operated master switch driven by the motor and having certain normally closed contacts connected to the first control switch and the second control switch for completing a starting connection to the motor when the normally open contact of one of the control switches is closed while the other thereof is in normal position. and other contacts operated by the cam for connecting the code contacts to a transmission line for code transmission nutil the code wheel has completed an odd number of half revolutions to thereby transmit a first signal of character determined by the abnormal control switch and for subsequently connecting the code contacts to the transmission line until the code wheel has completed another half revolui-.ion to transmit a restoration signal in response to actuation of the abnormal control switch to normal position with the other control switch also in normal position.

12. A transmitter for transmitting signals differing from one another in their characteristics comprising a motor, a code transmitting switch driven by the motor for transmitting first signals iollowed by second signals, an operating circuit including a line, a main control switch having an abnormal position and a normal position, a secondary control switch having an abnormal position and a normal position, means associated with said secondary control switch for modifying said first and second signals a motor-operated transfer switch connected to the line forsuccessively establishing connections from the line to the abnormal positions and normal positions of the main control and secondary control switches. and a master switch for completing a starting connection to the motor and for connecting the code switch to a transmission line for code transmission when one of said control switches is moved to abnormal position while the other con trol switch is in normal position.

13. A transmitter of the character described comprising a motor, code transmitting means driven thereby and including a unidirectional code wheel and contacts operated thereby for transmitting signals, a plurality of sets of signal initiating contacts, means associated with one set of contacts for modifying the signals transmitted by said transmitting means a transfer switch means for successively establishing connections to the contacts of saidsets and means for completing a starting connection to the motor upon the operation of any of said sets of initiating contactswhile the other of said sets of initiating contacts are in normal position.

14. A transmitter for transmitting different code groups comprising a motor, a code transmitting means including a unidirectional code wheel driven by the motor, an operating circuit including a line, a plurality of control switches having abnormal and normal positions, means associated with one of said control switches for modifying the signals transmitted by said transmitting means, a motor operated transfer switch connected to the line for successively establishing connections from the line to the abnormal and normal positions of said switches and a master switch for completing a starting connection to the motor and connecting the code transmitting switch to the line for code transmission.

15.A transmitter for transmitting different signal code groups comprising a motor, control means therefor, a code transmitting switch including a. code Wheel driven by the motor for transmitting rst signals followed by second signals during the parts o! a divided cycle of transmission, the signals transmitted in the parts of said divided cycle being indicative of different conditions of the control means for said transmitter a master switch operated by said motor for completing a starting connection to the motor and connecting the code switch to a transmission line for code transmission, contacts operated by the motor for interpolating code impulses in the signal code transmitted, and means for maintaining said contacts in operation during a complete cycle of signal transmission.

MANFRED W, MUEHTER.