US787344A - Electrical fire-alarm apparatus. - Google Patents

Description

PATENTED APR. 11, 190,5.

J. P. ROBERTSON.

ELECTRICAL PIRE ALARM APPARATUS.

APPLICATION FILED AUG.13, 1902.

5 SHEETS-SHEET 2.

MM. M

PATENTE!) APR; ll, 1905.

J. P. RBERTSON.

ELECTRICAL PIRE ALARM APPARATUS.

APPLICATION FILED AUG.13, 1902.

5 SHEETS-SHEET 3.

No. 787,344. PATENTED APR. 11, 1905.

J. P. ROBERTSON. ELECTRICAL PIPE `,111111111 APPARATUS.

.1 1-PPL1OATI011 PILPD AUG. 1s, 1902.

5 SHEETS-SHEET 4` VV TNESSEYS l AT ORNE",

PATBNTED APR. u,

No. 787,344. A

J. P. ROBERTSON. ELECTRIGALPIRE ALARM APPARATUS.

APPLICATION FILED AUG. 13, 1902.

5 SHEETS-SHEET 5.

/A/l/E/V? pgleWa-M.,

i ATTORNEYS W/TNESSES.'

a me UA1/@LA UNTTED STATES Patented April 11, 1905.

PATENT OFFICE.

ELECTFHCAL FIRE-'ALARM APPARATUS.

-SPE012]?"ICA'JJIN forming part of Letters Patent No. 787,344, dated April 11, 1905.-

Application filed August 13, 1902. Serial No'. 119,571.

Be it known that I, .Mules PEicoIvAL Rorzu'rsox, electrician, a subject of the King of (xreat lritain and Ireland. residing in the city oi Sydney, in the State of New South virales;-

Australia, have invented new and useful Almprovmnent in Electrical Fire-Alarm Apparatus, of' which the following is a speciiication.

My invention relates generally to automatic alarm systems and apparatus, and more particularly to automatic lire-alarm systems and apparatus; and my invention has particular reference to alarm apparatus adapted to be,

but it will be understood that` any other pri-f" mary actuating device, such as are or may be' commonly used in alarm systems, may be employed in place et' the thermostat herein described.

My inventlon consists in the operation of telephonographic signaltransmitting mechanism by 'an electric motor in a local circuit controlled by a primary actuating device, such as a thermostat; in automatic contact mechanism which normallf,7 holds the' telephonographic or other signaling device isolated from the line-circuit, but is arranged to connect such signal-transmitting means at the proper time with the line-circuit and likewise to operate suitable signaling means at the central station to attract the attention ofanoperator; in-

means adapted to be operated 'from such central station foresto'pping the operation of the signal-transmitting mechanism; in a novel -local alarm-indicator adapted to be placed on the outside otfa buiiding protected byl my system or at any other convenient point forindicating the place from which the alarm originates, and. iii-various other features hereinat'ter described, and particularly pointed out in the claims.

'ln thc system herein described I locate at suitable points signal-transmitting means connected to the wires ot' a central-alarm system or central-exchange telephone system. Such signal-transmitting means comprises means' for sending through the wires of such system a telephone message or other characteristic signal which. may serve to dlerentlate the alarm trom the signals ordinarilysent over words to indicate the character of the alarm f and the place from which it is sent-such, `for example, as Fire at No. 100 King streetand a combined phonographic reproducer and telephone-transmitter having a single diaphragm serving both for the reproduction of the recorded sounds and the telephonographic ytransmission thereoi` to the line-circuit. `This telephonographic signaltransmitting device is normally isolated from the telephone or other distant alarm-line and is connected therewith automatically when an alarm is to be sent in, provision being made for cutting it out ot' the line-circuit after the alarm has been transmitted, so as to reinstate the telephone or other line-circuit in its normal, condition.

Primarily the signaling apparatus is thrown into action by a primary actuating device, such as a thermostat, andwhen in action is connected to the line-circuit in parallel with the subscribers telephone instruments; but the current used while transmitting the alarm cannot injure the telephone instruments. Currents ordinarily used in the oper- 'ationI of the telephone-calls and telephone instruments cannot affect the alarm apparatus, and, in fact, it is not possible to alfect the local alarm apparatus by means of any current sent through the telephone-line except w-hile the alarm is Abeing sent in, at which time a current of suitable strengthsent through the line for the purpose of ,disconnecting the alarm apparatus from the telephone-circuit ICO and stopping its operation will ei'i'cct such result. My invention therefore enables a central-exchange telephone system to be requisitioned tor tire-alarm purposes with per- Vfeet security that the operatin of the .teicphone system can in no way be disturbed or injnriousiy affected and vithout expense, as no modiiication is required either at the exchange or at the subscribes or branch instrumcnts` The explanatory drawings annexed are ior the most part diagrammatic; but where necessary the vapparatus used is shown in detail.

in the drawings, Figure 1 shows diagramot' f1-localA alarm-indicator employed in connection with my system and comprising' a plurality ci indicator-lamps and an alarmbeli,- Fg'. e shows a vertical sectional cle- Vation et' this local aiarm-indicator, showing the main iamp and one of the indicator-lamps and the bell and its n'iotor and also showing' thewveatiier-hood over the 'front ot' the indicator. Fig. slowsaffront View of the vtace of encierro of thermostat which 1 may use and in particular shows the three contact-iin- :ofV the thermostat and the return-circuit.

Figs. YSand '7 are similar vertical sections ot' f two forms ot' such thermostat, the instrument i of Fig'. 16 having a fiat back drum and that of Fie. 7 having adruincorrugatcd on both sides: Fig'. 8 shows a sectionthrough a thermostatflkicad `and the associated clockwork lmechanism used 'forthe automatic time-sig'- mil by which the messagefto fire-station is cut eti after a predetermined interval has 'f ilapsed.v Fig't 9 shows a front elevation otl this instrumenta portion et the case beine; broken away.y Fig'. 10 shows a front elevation of thethermostat only oi the instrument Fig. t5, showing` the arrangement of the levercontact and clockwork interruptor. Figs. '11, .12, and 13 are detail views of the centrifugal switch controlling the circuit oi the microphone 20, Figi'. 11 showing a side view and partial section oi the switch on a scale larger than thatot' Fig'. 1, Fig'. 12 showing a .tace View, and Fig. 13 showing a sec- Ltion, ol'l the shaft ot the switch, illustrating v`the insulation of the two sections thereof 'from eachother. Fig'. 14: shows a detail section of the' combined rcproduccr and telcphone -transrmtteiz Fig. is a diagram I similar to the lett-hand portion of Fig. 1, but

showing` an alternati ve torni of signal transmitting' device which may be emiiioyed.

Referring" now to Fig'. 1, in said figure l show a subscribcNs telephone-tine 1. provided with ordinary telephoneI instruments, y.alarmtransmitting;l means comprising an electric :noter 22, driving a telephonographie transmitting; device 2O to 52, and suitable contact mechanism, hereinafter described, such alarmtransmitting' mechanism connected to the telephone-circuit by a conductor 2, a plurality or" thermostats 30" to 30"', inclusive, cach of which when operated will cause the connection et the teleplionographic signaling'device to the telephone-line a local-alarm-indieatingv device comprising' lamps A, I to and abcll l 3ft and other circuits and instruments hereinafter mentioned.

Referring now to the tcicphonographlc-signal-transmitting device, its motor, and the contact mechanism operated thereby, the branch 2 from the telephone-line is connected to the contact 3 oi a centrifugal contactmaker A.

5 is a line between the contact (i and one pole oi the battery 7, the other pole oi' which is earthed at ti.

9 is a line comiecting' the contact 1() to the secondary 11 ot the ind notion-coil '12, the iar end ot such secondaryT being carthcd by means of a line 13.

111 14.-" is a circuit with battery l5 connectingthe two heads 17 and l8 ot' the centrifugal contact-maker 1S) and the two binding'- screws of the microphone reproduccr 20. This circuit/14t .1i-1^ runs through the primary 16 ot thc induction-coil 12.

21 is a line connecting one terminal of the motor 22 with a contact-poin-t` 23 in the coil cut-ont. cut-ont is connected by a line 25 tothe motorbattcry 26. The motor-battery 26 is grouped with a local-alarm-bell battery 27 and a localalarm-light battery 28, the returnsof all ot' which are connected in a line 29, which connects the contact-plates ot'the several thermostats'SO" to 30"' together. These thermostats, as indicated in Figs. 6 and 7, comprise metal drums (51, to which are connected pipes 75, which may contain an expansible liquid or gas which will be expanded by rise of tempe 'ature, arising the flexible drum-heads to buckle outwa rd. Each such drum is provided with a contact-plate te make contact with three contactlingers or points when it is moved by the thermostat. The contact-points may be in the form ot' light spring-plates. One of these contacts at each lthermostat is connected to a line 31, which leads to the second tcrn'iinal of the motor 22. `Whcn, therefore, a thermostat-contact is closed, the contact made at the point connected with the lirie 31 completes a circuit tl'irough the motor 22 and the return-line 29 through the battery 26, and so long" as the contact is maintained at the thermostat the motor 22 will be rotated and operate certain other mechanism in the dist-ent call apparatus, hereinafter described,

until .its circuit is broken by an automaticl The other terminal 24 of the coil,

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IIS-

BEST

y cut-out or ringing off, so that the conlocal alarm-bell34 is worked. Thenceit passes to the battery 27 andobtains its return through the. line 29.' The closing of the thermostat-contacts therefore puts the bell-motor into operation, and this motor is kept operating until the contact at the thermostat is Abroken by restoring the buckling plate-head of same' to its normal position. The third contact 35" to 35F vfrom each thermostat is for the purpose of serving local alarm-lamps A to which aredesigned to indicate on the exv terior of a building that a lire is alight within it and toindicate, further, when necessary the location of such fire in such building. These contacts must therefore each of them be connected to a separate circuit, as many such circuits being required as there are floors or localities in the building or block of buildings required -to beseparately indicated, 1n the indicator| shown'in Fig. l the floors are designated by letters A to F, indicating floors or localities known by the same lettering, or

. governor principle.

" centrifugal. force the plates 42 and 43 figures may be used in place of the letters, asinI Fig. 3. These several circuits are marked v35", 35B, and so on, according to the indicator and -the corresponding' thermostat to which they relate. '[hese indicators A to F are each separately in series, with a masterindicator G, whence a line 36 is carried to the battery28, and a return obtained thence by the line 29 to the thermostat.

The shaft 37 of the distant call-motor 22 is extendedand carried in suitable bearings. It carries two contact- makers 4 and 19, to the detail construction of which, as shown, 1 am not l limited, as there may be substituted therefor other kinds. of known contact-makers which are adapted to closecontaets when certain movements are madeA automatically by the raising of the speed above a predetermined point. The contact-maker 4, which 1 find a convenient appliance, works on the Pickering vIts hub parts 33 and 39 are electrically insulated from the shaft 37, upon which 39 is immovable. The springs 40, which carry weights 4.1, join a pair of 'metal rings 42 and 43. which are mounted on these hubs 38 and 39. The ring 43 works against the contact-plate 44, which is electrically connected onto the line 2, but otherwise' insulated. The plate or ring 42 is adapted to make contact with the contacts 6 and l0 sucjcessively, with the former while rbtating at a lo\v rate of speed and with the latter when rotating at a higher rate of speed, when by are brought more closely together. t p

45 1s a metallic brake-shoe mounted on the contact 10. lf the speed of the motor should spring mounted on 10.

lbecome abnormal, ythe effect would be to increase the centrifugal action in the balls 41, thereby drawing the plate 42 inward beyond lthe predetermined point necessary to make mere contact and would thereby bring it up against thev brake-rubber 45, friction with which would diminish the vmotor speed to the normal. The contacts 6 and mare electrically isolated. They are `supported from a `standardsuch as 46, by an adjustingscrcw and -back nut 47, whereby they may be set up so asto complete the contacts either at a lower or higher speed of the motor, as may be rcquired. Exact adjustment to suit the motor speed, the stid'ness of the springs 40, and the conditions of other parts may thus be obtained. The contact-maker 19 may be of the ordinary centrifugal type, such as is used in connection with certain descriptions of telephones,

.and comprises a spiral spring i8, secured to one section 80 of a shaft forming an extension of the motor-shaft 37 and provided near its extremity with a weight 81, and a disk 1S), secu red to another section, 82, of the motor-shaft extended, secticns 8O and 82being insulated from each other by an insulating-coupling 33, Said disk carrying a contactdinger 17, with which at a predetermined speed of rotation spiing 18 will make contact, whereby spring i8 being in electrical connection with bearing-:bracket n 46 and finger 17 in eleetricalc'onnection with bearing-bracket 46A the speaking-cireu it ( lines 14 and 14") will be closed through the primary 16 of the induction-cod 12. The plate 42 makes contact with 6 onlyfdr'a'small fraction of a minute while it is passing over lightly in contact with it. The piece 6 may be in the form of a light bent spring-plate. T his contact occurs soon after the moto-r has been started and before it has reached its normal speed. Before the motor quite attains its normal speed the plate 42 is moved beyond 6 and breaks the circuit. lVhile 42 and 6 are in electrical contact the calling-battery 7 is put in parallel with the telephone instruments, an' earth or metallic return 8 being used for this calling-circuit in the usual Way. Current from the battery 7 then passes through the telephone-line to the central station, causing an annunciator-shutter to drop or illuminating a signal-lamp or operating whatever other signaling device is provided for attracting' the attention of the operator. When the motor 22 has attained its normalspeed, contact is made between the plates 42 and 1() through the rubi-l bing contact 45 or `through a light brush o1' The contact of these plates 42 and 1.() closes the speaking-circuit from the lines l and 2tl1rough thc'linriland the .secondary 11 of the induction-coil l2 and the earth or metallic return 13 to the telephone instruments at the central station. 'lhef-cirlcuit of microphone-rcprmlucer 21.) bcingcloscd at this time through switch if), and the phonograph-disk 52 being in rotation. telephonie lOO speaking-current only is passing.

fluctuations produced by he microphone in the line 1st la" induce in passing through the primary coil 16 oi' induction-coil 12 similar iluctuations in the secondary circuit of saidv the telephone-circuit through which the alarm is being transmitted to the telephone-circuit ol the {ire-brigade in the ordinary manner. The induction-coil 12 is set up so as to `form the electromagnet of a cut-out device associated with mechanism like that used in anordinary exchange-shutter. Said mechanism consists ot' a bell-crank lever 48, with armature 49 and catch-tooth 5() coacting with ad rop-shutter 1, provided with a spring 24- or a counterweigh'.. The speaking-current which ru-ns through the coil is insuiiicient to excite it sullicicntly to attract the armature 49, so that the shuttercontact remains closed while a ringing-up or ll", however, while that current is passing' a biglivoltagc curr-entbe sent through the secondary of the induction-coil, the coil will become sufiicieptly magnetically excited, and the armature 49 will bc attracted, with the resultthat the bell-crank lever 118 will be canted, freeing the shutter 51 by releasing' the catch-tooth 50, whereby the contact between 23 and 24 (51) will be broken and the whole distant-call mo- 'tor-circuit thus interrupted, whereupon the motor and all the rest of the parts of it which it actuates will come to rest and be electrically isolated from the telephone-line. The motor 22 is 'also geared to a circular drum or plate 52, mounted on a bracket, such as 53, or if the motor be su lliciently slow running the circular disk or drum 52 can be attached directly to its shaft. On the edge of this plate or on its 'face near the edge is set a gramophoncrecord 54, impressed or'printed in a strip of metal, cbonite, or other suitable substance, which is dropped and fastened into a circular' slot in or near the periphery.

1n order to make a phonograph or graniephone available for the purpose of sending a telephonie message in the way described, a certain modilication in it is necessary. It is not practicable to obtain reasonably clear v enunciation through a telephone-transmitter receiving its impressions from .soundwaves `emitted from a diaphragm of the ordinary phonograph or gramophone type, such diaphragms consisting of very thin iiexible sheets oi' glass or other higlily-elastic substance. On this account in order to make the invention practical l combine a microphone directly with the spcaking-diaphragni and make cer- 'tain modifications in the diaphragm itself,

which if of the Ordinary description above referred to would not satisfactorily coact with the carbon transmitter. 1 have found itmost advantageous to use a diaphragm which would be almost entirely-useless for ordinarypho` nographic purposes, for which the diaphragm is required to emit audible sound-vibrations. 1 have obtained satisfactory results by using a diaphragm o'iron or steel plate of considerable thickness, preferably about one-ftieth of an inch, using behind it a carbon transmitter of the lhlunuingsl type, in which loose particles (it carbon lill a cavity in a carbon block, so as to make microphonic contact between that plate and the diaphragm-plate. Such transmitter is illustrated in Fig. 11i, in which numeral 84 designates the diaphragm, and 85 the tracing point or needle connected therewith. The very delicate vibrations set up in thediaphragm:plate by the tracing point .or needle of the phonograph or gramophone are too feeble to produce audible sound-vibrations with any degree of clearness of articulation; but they are, however, of the proper character to act with a microphoniccontact, so as to al'iect the current passing', as in a telephone,and reproduce the record telephonically with a highly satisfactory degree of clearness.

1t is of course necessary to provide a specially-made record cylinder or plate for each premises in which the apparatus is litted. The manner of and apparatus for making such records are well known to qualilied persons.

20 is a microphone of the general character just indicated. lt is served by the battery 15, and its currents pass through the primary 16 of the induction-coil 12, the circuit being closed by the circuit-closer 19, which is so set as to elect the .closure immediately after the plate a2 has passed over the contact 6, as already 'lescribed.` A single message' is imprinted on the strip5-1,and the peripheral speed of the disk 52 is so regulated as that the record will speak clearly through the microphone. 1 have obtained very successful results when the diameter or' the plate 52 is aboutten inches and its speed about two hundred rotations per minute. It is not possible to send the current olil the calling-battery 7 through the microphone. 'lhe onlybattcry which can be connected with it is 15, which is a two-cell battery` asA ordinarily litted to work a microphone. Once started the gramophone will continue repeat-4 ing its record through its` lilies 14 and 14", through the primaryol the induction-coil 12, thereby sending a secondary current through the lines 13 and 9, the/contactl 10, the plate 42, the'springs 40, the plate a3, and the line 2 into the telephone-line 1.

1t is necessary that the local indicator' ivthin the casing 57 should bev distant from the other part of the apparatus, so as notto interfere with the clearness of enunciation of the gramophone.

IIO

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ing the place of the induction-coil 12 in Fig.

-tain simplification in the apparatus and cir- Y Wherel the gramophone device is used, the exchange attendant merely Aconnects the ring- .on the periphery ol' a disk, such as 52, may

8, Q, and isuscd.

Instead of providing the disk 52 with al gramophone-record it may be provided with a series of contacts and insulatingpieces around its periphery lworking-against a spring plate or brush, the 'contact device thereby formed being placed in the signaling-circuitiv in lieu of the microphone 20. Such arrangement is illustrated in Fig. 15` in which numeral 52' designates the said disk having alternated conductive and insulating spaces on its periphery, and numeral designates the said brush. Obviously the disk 52' and brush 20 might be connected to wires 14,- and 14, Fig. 1, in place of the microphone 20, a bati tery being included in the circuit to supply l current; but since there is no need to employ an induction-coil with 'this arrangement it is preferable to earth the disk 52' and to connect brush 20' by wire 14' to one end ot' the coil of a'magnet 12', to the other end ot' which c conductor 9 is connected, the said magnet tak- 1 and, like said induction-coil, operating the shutter 51. When the disk operates, the intermittent current Aproduced by the passage of the'disk under the brushjvill produce in the receiver of the central operator asound which is readily distinguishable Afrom .any Sound obtained through an ordinary telephone instrument, thus indica-ting an alarm. A cercuifts would thus be obtained, but at the expense ot' some delay in the reading of the signal at th'etire-staton. as it would be. necessary for. the exchange attendant to inform the lirestation per telephone of the telephone-number from which the call was received, so as to enable the firestation attendant to refer to an index. and discover the location of the tire by ascertaining the address corresponding with the telephone number so received.

ing-line to the exchangeas for an ordinary subscribers calla'nd the apparatus does the rest,- forl it conveys a spoken message to the lire-station operator, telling him theexact address at which the calling apparatus isin operation.

.The arrangement of the gramophone-record he modified in various ways without departing from the principieel' the invention.

Where it is required thatl thc 'transmitted message, whether in the form'of an intermittent current ora spoken messagcfshall b ceut off automaticall y aftcra predetermined period, the additional mechanism shown in Figs. 2,

This mechanism consists qta buckling-plate head 58cont'olled by the d rum-head at the end of the thermostatpipe. To the roar of the head is a lever 59, with a catch-point 60. This lover is mounted upon a pin 6l, set n'ear its lower end, which i latter takes its bearing'against the bucklingi plate 58, and by virtue of the greater proportionate length. of its upper part the'catchpoint 60 has considerable amplitude of motion. In front 'of it is set a clockwork mech-' tate a contact-finger 62 around a dial.' The catch-point 60 normally'engages an air-fan or other portion of the clockwork mechanism, so as to Y prevent the same fromlmoving.

i lVhen, however, the normal. pressure within the drum 6 1 is raised by the warming of the air or liquid in the thermostat-pipe, the catchpoint 6() is withdrawn and the clockwork mechanism rotates, carrying the contact-piece 62 around the dial. more segment-plates 63 63, each connected to the line 31, and two or more interruptingsegments 64. 64A of vulcanite or other nonconductor. In one of these segments isa stoppin 65. YVhen the contact-piece 62 is rotated, 35

it passes over the several'contact-segments 63 and insulator-plates 64, successively making contact and cutting off same, finally coming to rest on one of the insulator-pieces 64. The

movement of the contacthand-62 may be reg- 90 ulated for a predetermined pace, so that it will occupy, say, three or four or live minutes in making the circle. During the rotation xthe whole apparatus'-tliat is, both the local alarm and the.distant signaling portion of it--is 954 worked repeatedly, asit so many separate calls were being received; The contacthand 62 being connected to the return-line 29 completes the circuit with the line 31, alternately sending current tothe motor 22 to operate it #100 and then cutting that off as the hand 62 passes over an insulated segment, allowing the whole ot the distant alarm mechanism to come to rest. In coming to rest and in speeding up again the exchange is twice rung up, the ring- IOS ing being succeeded by the speaking of the message gramophonically. The only re etting required by this apparatus is to replace' thekhand 62 on the-other side of the pin 65,

against which it has come to re'st,"and to re- 1w' wind the clockwork which has been' in action. The ringing-off circuit through the secondary of the induction-@i112 and theV shutter-cutout may therefore in this ca's'e omitted.

The lever 59, carrying the catchpoint. 60, ,H5

must, however, madcto 'close thecircui'ts through the lines y32 .and.35. 1t is readily- Amade` to `do this "by being made tofslide over two contact-points at the terminals of thesev lines-.at each thermostat, respectively.

to separate lioors` or apartmeptser sections of a building or block. are marked,-respcctively,

1,42, 3, and so on. 'They aresct in closed cases 70 to protect them from the weather,and the 125 at the top, so that cach of these ,circuits lserves 130 The dial consists of two-or two lamps placed in series with one another. The motor33, operating the local alarm-bell 34, obtains its current from the battery th rough the circuits 29 and 32, which are closed by any one of the thermostats becoming affected by arising temperatureinits tube.v As the lampcircuitA 3629 and this motor-circuit 29 32 are positively closedv by the buckling of the thermostat.- lighted and the bell 34 will continue'ringing until the affected .thermostat-plate has been reinstated in its normal condition. This bell and lamp 'alarmbox 57 is'seton the outside of a building or in some place adjacent thereto within public view, and if properly cased need not be protected froriifth'e weather. lts purpose bell and exhibiting the lamp-signal as soon as i); fire has broken out 'within the area served y it A 1 t The lamps, or the portions of the coverglass immediately adjacent to the several lamps, may be provided with suitable words or letters; visible when the lamps are lighted, indicating. the existence ot' a fire and the location to which cach lamp corresponds.

The thermostat illustrated in the drawings is especially adapted to voperate with my sys-A tem herein"described and forms the subject- `matter of a divisional. application for Letters Patent. filed .October 7 v1903, Serial No. 176,052. Asalready stated, it comprises a drum 61, havingaliexible corrugated head arran'ged by. its movement to actuate acontaetplate-and contact-fingers (see Figs. l6 and 7) or'atripping-lever 59 (see Fig, 8) anda'tiibe 75, connected with said drum and containing an expansibleliquid' or gas. Q, 'I i The tube 75 is` a tube ot' small diameter'of lthe necessary length and'ot. any material not acted on by the expansive fluid used. When the thermostat operates'coiitact-fitigers of circuits 31, 32, and35, as shownin Figs. 6 and 7, thehead'of the 'dr um 61- is'I not allowed to come directly into contact'with'thcse contactvmaking' pointsot' the lines Z111, 32., and 35; but there is .a false head 58 for that purpose, which false head is acted upon by the drum-head pressing behind it. 'This false head is .buckled slightlyfso as to. remain eitherydelinitely in contact with the contact-points when buckled outward from the drum or definitely o ut of contact with them when buckled inward towardv the d rum. rugatcd .plate 58, such as is used in an ane'roid baroiiietei', mounted Ona' body Dortion 73.

through screws 72,- l'i'y which the wires 29 are secured to it. vThe contactpoints 31,32, and

35 are fixed in the casing 73 by 'screws which connect to them, respectively, their wires. f 'lhese con tact-piecesBl, 32, "and, 35 are of f i'exif ble metahand their neighboriiig'ends are set in such a position that when the false head 58 is buckled outward 'it comes into contact'with all ot' them and byvirtue ofits ow n elasticity keeps plate, thelamps will continuey is to sound a local alarm by ringing the' lt consists ofa circular corin contact with them until pushed back by hand, and so reinstated in its normal position. T he con tact-pieces may be set by bending them or to obtain greater nicety of adjustment may be provided with setting-screws. The drum may have a flat back, asshown in Fig. 6, or a corrugated back, as shown* in Fig. 7, and when in the latter form will' befoupd to be more sensitive. 74 is a knob on the head ot' thisdrum 6l for making contact with therear side of the false head 58. Thei drum 61 is air- .tight and operates after thelma'nner ofthe drum in an aneroid barometer# The thermostat-pipe 75, being the end of the thermostatpipe which is carried through the apartment to be protected, is carried into this drum 61.

In operation when the temperature is raised i so as to affect the liquid or air in the pipe 75 such liquid or air presses upon the liquid or air in the drum 61, distending the heads and causing the pin 7 4 to press against the false head 58.

completing the cireuitthrougli theirwires'and thev line 29. It will be seen that the contact between 58 and 31, 32 and 35 is a rubbing. contact, and the pointslotl gether with elastic force. By keeping the head 58 pressed inward, so as to be almost at vits buckling-point under n ormaLconditions, a

very slight elevation-of temperature will cause- When this head is pressed upon 4sufiiciently, it buckles outward, making contact with the contact- points 31, 32, and 35 and contact are kept tosut'n'cient expansion to push it over'its center I and `make it buckle outward and quickly pass through a considerable distance andcomplete the alarm-contacts; A'maximiim'of-reliability is secured class. 1t involves a minimum number of contacts, and, as will be. shown later, the arrange? ment. is Suchthat the failure ofany one coiitactcannot alfect the others in the system'.` Moreover, a very large area can be' servedby a single contact, and a response to very slight variations in temperatureI 'may be secured, All the contacts are self-cleaning. Very ready and the -best way of increasingthe sensitiveness ofv the apparatus is also'at hand, for the` fluid or air contained' in the thermostat'- pipes and the thermostat-d rum can be put under slightly-i ndi-eased -pressureat normal-tem# pcratures by pinching any portion of thether` mostat-pipe, preferably vits dead and, so as to IOO in a thermostat 'system ofthisreduce,.its volume.' The original 'setting of'v the apparatus may be most neatly regulated or varied by pinching the closed end of the thermostat-tube with nippers uiitil'the exact required condition of balance of .the contactiiiaking hcad'58 is obtained.Y

.Referring lo Figs.' 8, .9,a'nd..f10 76'isa clockwork mechanism operated." by a. spring- 4which requires to vbe wound to provide the motive power. At the end of thewhcel-train 7' is al1,aii'vanef77, while Aon the7 slowest-moving spindle ol the train isa contact'hai r`d'62-, which tliemovement ot' the train causesto ros' segments and broken when the contact-hand apparatus isthrown into activity,

' draw out-the lever59 from the contact-plates tor-segments 64 andv 64A, which separate the pleted .through the contact-hand 62, and these sciatori-segments.

Aanismhereinafter to be described followingr ving the whole of theV distant cail apparatus Ainto activityand repeating the call to thc ex- 'change' and tire station, de umu/,las if a second alarm had been given.

-on to the lower insulating-spaceand comes 4to more .(two onlyv shown)v"contactsegments 63 and 63A; connected by a wire and two insulacontact-'segments The circuit 29 31 is cornconducting-segments 63 and 63^ being closed when the contact-hand is passing over these is passing Lover orat vrest upon one .ot' the in- Norrnally--that is, in the positionA of lrest-thc contact-hand isk as shown in Fig. 9v. A-peg 65 is inserted behind it. Whenfth'e air-.vane is released by the mech-v upon th'e expansion of a thermostat-head, the clockwork mechanism comes into action and very slowlytrotates the contact-hand 62 around the dial; W'hen itpasses from the lower insulating-segmentonfo' the first conductingsegment63, the circuit to the motor in the distant .call .apparatus is completed and that When the contact-hand passes thence on to the upper insulating-segment of the dial, the motor-circuit inthe distant call'apparatus is opened and the `rmotor and connected apparatus come to resta. When, however, the hand passing beyond this insulating-segment passes on to the second conducting-segment 63", the rnotor-circuitl is `closed again, oncev more throw- Finally, the contact-hand passes from the second conductor rest against the peg 65, which prevents any further rotation. The air-vane is controlled". by a catch-linger on the end of a' long end leven 59, which is fulcrumcd at 61x on a casing 73, inclosing the thermostat-head 61'. The buckling o1 the false head -of the thermostat presses out against the lower end of this lever, causing its longupper end,carrying the catchlingeig to be retired out oflcontact with the ai r vane and over spring contact-plates 32 and' 35, completing a circuitthrough thc same and the line 29. The circuits connected to thedistant call apparatus are governed by the con tact-hand 62 'and 'segmentfplates 63 and63^ on the dial; but the circuits connected with the local 'alarm are those which are closed through the lever 59.; To reset this apparatus, it is necessary to restore the false head ofthe thermostat to its normal position to 32 and 35 land so that its catch-finger 60 will prevent the rotation ot' th'airfvane 77, and it is also lnecessary t0 rewind the spring-mo'- tor and to reset the peg 65 on therear sideo'f the contact-hand 62, as shown in Fig. 9,v

The mode of operation of th'e apparatus is as follows: The action is precisely thcsame in the apparatus, irrespectively of which of 'tate/ over a dial. -This dial consistsA of two or the thermostats 30 is affected. Assuming that the pressure in the t'ube connected with ther- .mostat 30A is increased beyondlthe critical point, so as that the pressure of the front of the drum 61 causes-the false head 58 of the thermostat to buckle outward, a circuit is closedthrough the lines 29, 32, 31, and 35". The circuit through 32` passes through the line 32.and the motor 33, causing themotor to be rotated and to ring the bell 34, thence by the line- 32 to the battery 27, returning to Y i tor 22, thence through line 21, the contact 23, l

and the spring-shutter 24 51 tothe Aline 25, thence tothe batt-ery 26 and returning to cornplete through the common return 29. 'The circuits through the lines -35 and 32 once completed, cannot be interrupted except by reinstating the false head 58 of the thermostat 130", so as to break the circuits at the contacts operating in connection with that false head.

'The circuit through 21 and 25 can, however` be interrupted independently ot' the local alarm-bell 34 and .local `light-circuits by the dropping of the'shutter 51, whereby contact between the point 23 and the spring-back 24 of the shutter 51 is broken.v The spindle of the motor 22 rotates the centrifugal mechanisms 4 and 19. The rotation 'of 4 causes the balls 41 fon the light spring-plates 40 to Hy outward as in an ordinary engine-governor,

whereby the end plate 42 is drawn in gradf tact with 6.

pies but a few seconds,va circuit is completed from earth through the battery 7 and the line 5, the contacts Gand 42,'the spring-plates 40, the end plate 43, and the rubbing-spring 44 to ually as the speed of the motor runs up. The plate 42 is so adjusted with reference to the contact 6 that there'shall be a definite gap while the motor is at rest, cutting outthe cirroo4 cuit 5 from the battery 7 from .the circuits connected'lthrough the centrifugal contactmaker 4; As the centrifugal governor is a sensitive piece yof mechanism, however, the comparati vely slow rotation of its motoigspinf die 37 suices to draw the plate 42 into con- 'l'n passing over 6, which occu- -the vline 2, and thence into the telephone-line, returning bythe exchange and distant tele'- phone instrument through earth. rl `his circuit from -the battery 7 is for calling the operator at the exchange, the battery 7 being of acharacf IIO its

tcr adapted for that purpose, and a single current-pulse from battery 7 -suiiices'todrop-the switchboard -shutter orA to opegjate v the relay control ling the switchboard signal-lamp correles spending to the line through which -the call is sent. W hen thcspcedof the motor has become sullcientlyhigh to draw the plate 42 past the :53 if if 'u' Email AV faltar-:Lani: ULM

' contact 6, the calling-current from the battery 7 is cut oli'. Shortly'afterw'ard-that is,when the motor is approximating to its normal speed the plate42 is brough t into contact with the knob 45 pn the-stem 10. The friction between the plate 42 and, the knob 45 makes a good electricalcontact, while it su fiiees to act as.

` a brake uponthe'motor. Upon'con tact between 42 andtakjn'g place a circuit is completed from the telephone-'line 1 through the line 2, the contactspring 44,l plate 13, springs 40, and plate -42 and contact 45 10 to theline 9, thence thrpu h th'esecondary winding 11of the induetion-coil 1,2, and thence to earth by the line 13,

returning throughearth and the distant telephone instrument and exchange. to th'e telephonjejline 1. xThe other centrifugal con'tactmaker` 1 9 is .adapted togclose the electrical con- .tact between its; twoends 17 and 18 when the speedgof the 'motor approximates its normal.

-When this takes place, 'the circuit is com- 4platedirornthc ,speaking-battery 15 by the supporting-' standards 46 and 46A tothe line 14, thence throughfth'e' microphone 20, and 'l theneebytheline 14A. through the primary 16 of thehinduetioncoil12to the battery 15. e vThe currentsfromthe batteries 7 and15 are` of too low'atension yto alfectthe energizing of i armature 49. IiiI however, while the motor` -22 is running atjitsl` normal speed and the circuit is completed through 17 and 18 and42 and 45.1Lringotfeurrent is received from an. ordinary telephone instrument through vthe line 2that" current passing through the' secondary 11 ofthe coil 12 will suiiice to energize that eoilsufiiciently to attract the armature 49. Upon that armature being attracted 1 thetbellcrank leverv48, on which it hangs,.is

eanted sothat its catch-point will be lifted up from the til-p of-the shutter 51,- whereupon the spring 24, reacting against the contact 23 will throw open lthe shut-ter. thereby. interrupting the-circuit between the lines 21,. and The, interruption of this circuit-cuts out the m'oter-batteryA 26, and,;th e motor and l the Who-leof-theapparatus thenfcomesto rest.,

The motor-22, rotates the; plate 52,'fon the edge of which is set upthc gramophone-rec.- ord51.l7he-vilrrationof thodiaphragmfplate of the .ni-,icrophenellh due toits. needle running tliroughthe-,reeord on 54;, .varies the resistance, innthewcll-known manner in the microphonegand so governs-the current 4from the battery;1.54mThis;undulating;battery-current passingrth rough the, primary16 of the. ind uction-coil12 setsulp tlieisecondary l 1 ot' the samecoiha line-current.'which passes. to the telephone-,line and is of the character required for telephonespeaking` purposes. .'.lhe rota# tion of the,motoxl22gthereforc lirst sends intethe lineacallingicurient-from the battery'. I This current passesonly fora sullicient time to operate the annunciatorshutter-,signallight, orfotherv Signaling device employed at' induction-coil 12 of'a'ringing-oii' current per the telephone-line. The eurrentvfor driving the motor 22 is 'supplied by the battery 26, whose return is through the common line 29.

` A In the alternative arrangement,- in which a spring-motor mechanism is associated with the thermostats, the motor-circuit 21 25 is broken automatically. lfVhen the rotating' contact 62 passes from the lower insulated space 64 onto the contact-segment 63, the circuit is completed between the lines 29 and 31 andthe wholeof theelectrical and mechanical mechanism connected with the motor 22 and associated Y parts is put into action'. When the rotating 'contact-hand 62 passes onto the upper' insulat. l .ing-spacetf, the motor-circuit is interrupted-and the wholeo the electrical and mee' chanical apparatus referred to in connection' A with the distant-,call apparatus comes tolrest. r When the rotating- 'contact62 again passes 1onto the second contact-segment 63", the whole; ot'- the said distant-call apparatus is 'restoredto working eondition.- the exchange being rung up and the speaking-circuits cut in afresh f just as if a new call -were being sent.' Finally when the rotating contact 62 comes tovrest onthe lower insulatingfspacc .64 against the stop- IOC peg 65 the motor-circuit is again interrupted "and the wholeof the said distant-call elec.4 trical and mechanical apparatus finally comes'.

to restand eannotbe restarted until the peg 65 is' removed and reinstated on the other side 'of the rotating Contact. The clockwork mechfanism 76 is permitted to rotate when the catchiinger 6l)on`the lever 59Ais withdrawn by the buckling of the false head 58 ofvthe thermostat 30. The backward movement of the upper end of the level' 59 throws its top end into contact with. the terminals ofthe-lines 32 35, completing circuits therefrom to the line 29, which connected to the pin 61 of said ln any :ase where the riiotorlcircuit 21 25 is broken automatically by mcansof the clockwork device or broken hyrmgmg ofi' trom the ve.\'changeor distant stationthe local alarmhell 34. and local signal-lights are maintained untilthe thermostat contact is reinstated in its' normal position. n l

When themotor 22 is slowing up and coming to restdiy reason of the breaking of its battery-circuit 21 25, the centrifugal contactmakers "It and, 19 gradually reassume their normal positions, sueeessh vely cutting. out the speaking-circuit and cutting in the battery- IlO circuit 'i' just before coming to rest, said battery 7 sending a ring-off current through the line 2 tothe 'telephone-line-' So that it will be seen'that, the distant-call apparatus is entirely autmatic, fi rst ringing up thc exchange,

then connecting up the speaking apparatus, l

and', haring delivered its message, ringing ofi' the exchange again,denoting thatit has'come and its clockwork mechanism.

, graphophone, and

to rest. VVhc-n the automatic clockwork cutout is used, the shutter cut-'out 'mechanism for breaking the circuit between 21 and 25 is not needed, and it is not necessary to reinstate any part of the distant-call'apparatus in order to put it into condition for'work again. The

only reinstatement ofpartstliat' is needed in.

that case is in connection with the thermostat Wvhen, however.' the drop-shutter cut-out is used, the

whole of the distant-call apparatus is reset mitter of the 'telephone part of the instru- 'ment are combined in one, as' above described.

'l do not limit myself to the' use of an electric motor for operating the signaler alarm transmitting mechanism. Any 'suitable motor may be used, although an electric motor Vis ordinarily the most convenient. 1

-l do not limit myself to theus-e'of telephonographicsignal-transmittingmechanism, as any device which when operating on the line-circuit will produce a characteristic sound' or signal at the receiving-station may be used. It is not necessary that the signal transmitted shall indicate by a'telephonic or telegraphic message the source from which the alarm originates', jas this is shown 'by the number of the switchboard or signal-lamp which is ope'rated by the incoming signal.

Then the systemlierein described is used as a central fire-alarm system not connected with a telephone system, there will beat the central station a switchboard substantially like a tele;)hone-switchboard, without speaki ing-circuits or telephone apparatus, the shutters or signal-lamps'of the switchboard showing the source from which the alarm comes.

lVhat l claim as my invention, and desire to 1. In an alarm system, the combination with local signal-transmitting mechanism comprising telephonographic signal-transmitting devices and an electric motor. for operating the same, and a line-circuit for connecting said signal-transmitting mechanism with a distant station, of Va local circuit supplying current to drive said motor, and a primary actuating de- Vice controllingsaid local circuit. 7o

2. ln a tire-alarm system', the combination with local signal transmitting mechanism comprising telephonogra'phic signal transmitting devices and an electric motor for operating the same,jand` a line-circuit for connecting said signal-transmitting mechanism with a distant station, of a local circuit supplying current to drive said motor, and a ther- -mostat controlling said local circuit.

3. l-n'an alarm system, the combination wit 80' local,signal-transmitting mechanism and aline- 'circuit for connecting said signal-transmitting mechanism with a distant station, said signaltransmitting mechanism comprising a motor,

a main signal-transmittingdeviccd riven thereby, and means for transmitting a calling-signal comprising centrifugal contact mechanism operated by said mot'oig'of a local circuit controlling said rnotor, and a primary actuating device controlling. said local circuit. 90

e. ln a tire-alarm system,Y the combination with local signal-transmitting mechanism and aline-circuit for connecting said signal-transmitting mechanism with a distant station, said signal-transmitting mechanism comprising a motor, a main signal transmitting device -driven thereby,l and .means for transmitting a calling-signal comprising centrifugal contact mechanism operated by said motor, of a local circuitcontrolling said motor.' and a therxo mostat controlling said local circuit.

5. In an alarm system, the'com'bination with local signal-transmitting mechanism and alinecircuit for connecting said signal-transmitting mechanism with a distant station, said signal- 1o\5 transmitting mechanism comprising a motor, 'main signal transmitting circuit varying means driven thereby, and centrifugal circuit-closing mechanism likewise driven by said motolgcomprising a ringing-contact and rio another contact in circuit with said main sig-4 nal-transmitting circuit-varying means, of a primary actuatingdevice and means operated thereby controlling said motor.

6.4 lna lire-alarm'system, the combination 115 with local signal-transmitting mechanism and a line-circuitfor connecting said signal-transmitting mechanism with a distant station, said signal-transmitting mechanism comprising a motor, main signal-transmitting circuit-vary- 1 zo ing mcan's driven thereby, and centrifugalcircuit-'closing mechanism likewise driven by said motor, ,comprising a ringing-contact and another contact in circuit with said main signal-transmitting circuit-varying means, of a thermostat and means operated thereby controlling said motor.

7.` In an alarm system, the combination with local signal-transmitting mechanism and a line-circuit for connecting said signal-transmitting mechanism with a distant station, said signal-transmitting mechanism comprising a motor, main signal-transmitting circuit-varying means driven thereby, a local circuit controlled by said signal-transmitting device, an induction-'coil arranged to connect said local circuit inductively with the line-circuit` and centrifugal circuit-closing mechanism like-f Wise driven by said motor, comprisinga ringing-contact and a main-line contact, arranged respectively to transmit a calling signal through the line and to complete the line-cir- -cuit through the induction-coil, and a localcircuit contact arranged to complete the said local circuit, of a primary actuating device and means operated thereby controlling said motor.

8. In a fire-alarm system, the combination with local signal-transmitting mechanism and a line-circuit forconnecting said signal-transmitting mechanism with a distant station, said las signal-transmitting mechanism comprising a motor, mam signal-transmltting circuit-varying means driven thereby, a local circuit controlled by said signal-transmitting device, an induction-coil arranged to connect said local circuit inductively with. the line-circuit, and centrifugal circuit-closing mechanism likewise drivenby said motor, comprising a ringing-contact and a main-line contact, arranged respectively' to transmit a calling signal through the line and to complete the line-circuit through the induction-coil, and alocalcircuit contact arranged to complete the said local circuit, of a'thermostat' and means opv erated thereby controlling said motor.

' controlling said motor.

10. 1n a lire-alarm system, the combination with local signal-transmitting mechanism and a line-circuit for connecting said signal-trans- 'mitting mechanism with a distantl station,

said signal-transmitting mechanism comprising a motor, a telephonographic signaling device driven thereby, and centrifugal circuitclosing' mechanism likewise driven' by. said motor, comprising' a ringing-contact and an-' other contact controlling the transmission of signals from said main signal-transmitting circuit-varying means through the line, of thermostat and means operated thereby controlling said motor.

1l. ln an alarm system, the combination A4circuit contact arranged' to complete the said local circuit, ,of a primary actuating devices and means operated thereby controlling said motor. 12. In a ire-alarrrrsystem, the combination with local signal-transmitting mechanism and a line-.circuit for connecting said signal-trans- Initting mechanism with a distant station, said signal-transmitting mechanism comprising a motor, a telephonographie signaling device, 9o an induction-coil arranged to connect said local circuit inductively with the line-circuit, and centrifugal circuit-closing mechanismV likewise driven byv said motor,'comprising a ringing-contact and a main-line contact, ar. 95 rangedl respectively to transmit a calling-signallthrongh the line and to-complete the linecircuit through the induction-coil, and a local circuit Contact arranged to complete the said local circuit,of a thermostat and means operioo ated thereby controlling said motor.

13. ln an alarm system, the combination with local signal-transmitting mechanism and a line-circuit for connecting said signal-transmitting mechanism with a distant station, said 1o 5 signal-transmitting mechanism comprising a motor having an 'electric controlling-circuit, main signal-transmitting circuit-varying means driven thereby, and centrifugal circuit-closing vmechanism likewise driven by 11o said motor, comprising a contact arrangedto operativelyconnect saidY main signal transmitting circuit-varying device with the linecircuit, of an automatic cut-out relay in the line-circuit, having contactsA in the controlling-circuit of said motor, said relay arranged to respond only toincomingsignals, and a primary actuating derice controlling said motor.

14. ln an alarm system, the combination with local signal-transmitting mechanism and x20 a line-circuit for connecting said signal-transmitting' mechanismwith a distant station, said, signal-transmitting mechanism Icompris-ang motor having an electric controlling-circuit,

a telephonographic signalingdevice driven 1,25 thereby, a local circuit connected to said telephonographic signaling device, an inductioncoil arranged to connect said local circuit inductively with the line-circuit, and centrifugal circuit-closing mechanism likewise driven by |3 I' 'A .motor, main signal-transmitting means driven thereby, and circuit-closing mechanism like- .wise driven by the motor comprising` means for com pleti ng a ringing-contact while the motor is atl low speed and for breaking. the ringing-contact and completing acontact controlling transmission of signals from said main signal-transmitting Ameans through the line,

when the motor'reache'shigher speed, of a primary actuating device and means operated thereby controlling said motor.

16. Ina lire-alarm system, the combination with local signal-transmitting mechanism and aline for connecting saidsignal-transmitting mechanism with a distant statiori, said signaltransmitting mechanism comprising a motor, main signal-transmitting means driven thereby, and circuit-closing mechanism likewise driven by the motor comprising means for completing a ringing-contact while the motor is at low speedand for breaking the ringingcontact and completing a contact controlling transmission of signals from said main signaltransmitting' 'means through the line, when the motor reaches higher speed, o f a thermo- Stat and means operated thereby controlling. said motor.

17. In an alarm system, 'the combination with local signal-transmittingmechanism and a line-circuit for connecting said signal-transmitti ng mechanism with a distant station, said signal-transml-ttmg mechanlsm comprising a 'motor, a telephonographic A.signaling device driven thereby comprisinga movable actuating member and a combined reproduccr and telephone=transmittr having a single diaphragm .performing the` functions both of a rcproducer-diaphragm and of a transmitterdiaphragm, and contacts controlling the transmission o f signalsthrough the line, of a primary actuating deviceand means operated thereby controlling said motor.

18. ln a 'fire-alarm system, the combination with local signal-transmitting mechanismand a line-circuit for connectingsaid signal-trans- 'mitting mechanism with a distant station, said signal-transmitting mechanism comprising av motor, a telephonographic signaling device. driven thereby comprising a movable actuatf ing member and a combined rcproducer-and telephone-transmitter having a single diaphragm performing the functions both of a reprodneer-diaphragm and of a. transmitterdiaphragm, and contacts controlling the transmissionof signals thronghthc line, oi a thermostatand means operated thereby controlling said motor.

19. ln an alarm system, the combinationI with local signal-transmitti ng mechanism comprising a telcphonograi'ihic signaling device and a 'motor for operating the same, end a line-circuit for connecting said signal-transmitting mechanism with a distant station, of a local circuit for supplying current to drive said motor, a plurality of primary actuating devices each controllingsaid local circuit, and a plurality of local signaling devices,A one for each' of said primary actuating devices and controlled thereby.

20. 4In a fire-alarm system, the combination withlocal signal-transmitting mechanismcomprising al telephonographicfsignaling device and a motor for operating the same, and a 21. ln an alarm system, the combination l -with local signal-transmittingmechanism comprising a motor for operating' the'same, and a line-'circuit for connecting sald signal-trans- `mitting mechanism W'itha distant station, of

a local circuit controlling said motor, a plurality of primary actuating devices each con- `trolling said local circuit, local signaling means coml'irising local signaling devices connected one in circuit with each of said primary actuating devices, and another signaling device connectcd in multiple circuit with all ofA said .primary actuating devices, said primary actuating devices arranged to setin operation both the local signaling devices and the locall signal-transmitting mechanism.-

22. In a lire-alarm system, the'combination with local signal-transmitting mechanism comprising a motor for operating the same, and a line-circuit for connecting said signal-trans- -mitting mechanism with a distant station, of a local circuit controlling saidl motor` a plurality of thcrmostatsV each controlling said local circuit, local signaling means comprising local signaling devices connected one in circuit with each of said thermostats, and another signaling device connected in multiple circuit with all of said thermostats, said thermostats arranged to set in operation both the local signaling devices and the local signal-V transmitting mechanism.

23. Inan alarm system, the combination .with local signal-transmitting mechanism and aline-circuit for connecting said signal-trans- .mitting mechanism with a distant station, said signal-transmitting mechanism comprising a motor and means for; transmitting calling aniI driven thereby, and means for transmitting a' calling-signal comprising centrifugal contact I mechanism operatedby said motor, of a primary actuating device, means operated thereby controlling said' motor,` and automatic re'- peating mechanism likewise controlling said motor and-arranged to cause; repetition both of the callingand of the' main signals.

( 25. In an alarm system,`.thecombination :with local-signal-transmitting mechanism and .a line conductorv for connecting said signaltion, of automatic stopping means therefor connected with the'same line conductor'and arranged -to respond only to incoming signals. 26. In an alarm system, the combination with local signal-transmitting mechanism, a

line conductor for connecting said'signaltransmitting mechanism with a distant station, and a local. circuit -controlling the operation of said signal-transmitting mechanism, of a stopping device controlling said local cir- '35 cuit and connected the same line conductor .said induction coil,'/of a line conductor'for and arranged to respond only to incoming signals in the circuitincluding saidline condoctor.

27. In an alarm system. the combination with local signaltransmitting .mechanism 40 comprising an electric' motor, a local circuit for supplying current to drive said motor, and a line conductor for connecting said signaltransmitting mechanism with al distant vstation, of an automatic switch connected to the 4S same line conductor,l arranged when operated to break said :local circuit,'and arranged to' y respond only to incoming signals in -the crcuit including said line conductor. i

28. In an alarm system, the combination 5C with an induction-coil, local signal-transmitting mechanism, and a'local circuitoperated thereby and passing through the primary of connecting said signal-transmitting mechanism with a distant station, connected to the secondary of said coil, a 4localeireuit control-l y ling the operation oflsaid signal-'transmitting transmitting mechanism with a distant stamechanism,`and contact mechanism operated by said induction-coil as a' magnet connected 60 tosaid local circuit, said contacta mechanism arranged to be voperated -bnlyby incoming signals in the circuit 'of said secondary coil.A In testimony whereof I-have hereunto set my hand in presence of two subscribing witnesses.

jJAMEs P. ROBERTSON.: Witnesses, y

W. J. SPRUsA, W. J. DAVIS. 4

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