US1363246A - Fire-alarm system - Google Patents

Description

GARL. FIRE ALARM SYSTEM.

APPLICATION FILED MAY 18, I917.

Patented Dec. 28, 1920.

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FIRE ALARM SYSTEM.

APPLICATION FILED MAY 18, 1917.

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FIRE ALARM SYSTEM.

APPLICATION FILED MAY 18, 1911.

Patented Dec. 28, 1920.

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FIRE ALARM SYSTEM.

APPLICATION FILED MAYIB, 1917.

1,863,246. Patented Dec. 28,1920.

4 SHEETS-SHEET 4.

/Z6' w' annex Jot afbozmua UNITED STATES MANIOUS GARL, OF AKRON, OHIO.

' FIRE-ALARM SYSTEM.

Application filed May 18, 1917.

To all whom it may concern:

Be it known that I, MANIoUs GARL, a citizen of the United States, residing at Akron, in the county of Summit and State of Ohio, have invented new and useful Improvements in F ire-Alarm Systems, of which the following is a specification.

The present invention relates to improvements in tire alarm and other systems which employ a number of instruments adapted to transmit signals to a central or otherreceiving station.

One of the primary objects of the invention is to provide improved contact or circuit controlling means for such instruments which will be unaffected by gases or other influences which produce corrosion and' thereby prevent proper engagement of contacts of the ordinary exposed type, in consequence of which good conductivity between the contacts is insured at all times, and certainty and reliability in the operation of the instruments are attained.

Another object of the invention is to provide a system of this character which has a normally closed line circuit which does not depend upon utilizing the earth or ground as a part 'of such circuit; and to provide a telephone having means for connecting it in series with the line circuit and having a local battery which is connected in series with the battery or source of energy for the line circuit, injury to the system or disturbance in the operation thereof by other electric systems which commonly use the earth or ground as a part of their circuit being avoided.

A. further object of the invention is to provide means whereby a break in the line circuit of the system may be quickly and easily located to enable the necessary repair to be made promptly and, pending such repair, the system will be in operative condition, using the ground temporarily as a part of its circuit.

To these and other ends, the invention consists in certain improvements, and combin-ations and arrangements of parts, all as will be hereinafter more fully described, the novel features being pointed out particularly in the claims at the end of the specification.

In the accompanying drawings:

Figure 1 is a front elevation, partly in section, of an instrument embodying the present invention, the instrument being adapted Specification of Letters Patent.

Patented Dec. 28, 1920.

Serial No. 169,567.

for use in connection with a fire alarm system.

Fig. 2 is a rear elevation of the instrument shown in Fig. 1.

Fig. 3 representsa section on the line 33 of Fig. 2, looking in the direction of the arrow.

Fig. 4 represents a sectionon' the line 4-4 or F 1g. 1.

Fig. 5is a bottom plan of the instrument as shown in Fig. 2.

Fig. 6 is a'detail'view, partlyin section, showing the circuit controlling device or breaker embodying the presentinvention.

Fig. 7 represents acentral' axial section through the circuit controller or breaker.

Figs. 8 and 9 represent sections on the line 88 of Fig. 2, the releasing lever for the instrument being shown in two diiierent positions in these views.

Fig. 10 is a diagram showing a fire alarm system having two instruments connected therein, the diagram also showing the telephone adapted to be connected in series in the fire alarm system; and

Figs. 11 and 12 are detail perspective views showing. respectively, the telephone jack and plug for one of the boxes or instruments.'

Similar parts are designated by the same reference characters in the several views.

The present invention is applicable generally to fire alarm telegraph systems or other electric systems which comprise a, number of signal-transmitting instruments and a central or other station for receiving the signals from the different instruments. Insystems of this character, and especially in fire alarm telegraph systems, it is of great importance that certainty and reliability in the transmission ofthe signals be insured at all times. It has been found, however, from experience, that the ordinary open or exposed contacts, such as those employed in the usual fire alarm systems, are corroded or otherwise attacked by gases, this being particularly the casewith instruments installed in rubber factories and other places where the contacts are subject to the corroding influence of sulfur gases. Corrosion of the electrical contacts of the instruments prevents proper engagement or electrical conductivity between the contacts, and when that occurs, the instrument and, in some cases, the'entire system, is rendered inoperative. It has also beenrfound that where the fire alarm system utilizes the earth or ground as a part of its operativecircuit, the system is liable to damage and to interference with its operation should the line wire of the system come in contact with the overhead or line wire of another electrical system, it being common in some localities to employ the earth or ground as the return part of the circuit of various electrical systems, and contact between the line wire of the fire alarm system and the line wire of one of the other systems would result in the flow of electric current from the other system I ings and will be hereinafter described as applied to a fire alarm system. It is to be understood, however, that the invention is not restricted to the precise construction and arrangement shown, as equivalent constructions are contemplated and will be included within the scope of the claims.

In the present instance, wherein the invention is shown applied to a fire alarm system, each instrument is preferably fitted into a suitable box 1 which may be of metal mounted on or attached to a post or pipe 2, the box being preferably groundedwith the post or pipe 2. A door 3 serves to close the front of the box and it may have a glass or other breakable panel 4 through which the releasing member of the instrument may be reached for manipulation without the necessity of opening the door, although the door may be opened by an attendant for inspection, repair or other purposes. The instrument which is preferably mounted in the upper part of the box 1, has its parts supported on a base 5 which is preferably grounded. with the box, and a front plate 6 is mounted on the base plate/5. The circuit controller of the instrument comprises a disk 7 of hard rubber or other insulating material which is mounted to turn with an operating shaft 8, and the disk 7 has pins or teeth 9 projecting from its periphery, the number and arrangement of the pins corresponding to the number of the particular instrument. For example, the pins are grouped to represent the number 151, it being understood that the number and arrangement of the pins on the different instruments in the system will be grouped in different ways so that each instrument will have its individual number. A casing 10 of suitable insulating material is secured to the front of the'plate 6, the casing having a rear wall 11 which closes it, and a glass 12 is adapted to close the front of the casing, this glass being removably held in place by a screw cap 13. The casing is preferably round, or substantially so, and it is provided at the bottom with partitions 14 and15 ofinsulatingmaterial, these partitions subdividing the bottom of the casing to form wells 16 and 17, and these wells contain bodies of mercury. Metallic conducting strips 18 and 19 are-arranged in the bottoms of the wells 16 and 17, these strips being preferably co-extensive with the bottoms of the wells and presenting relatively large areas of contact with the bodies of mercury, thus insuring the flow of current between the strips and the bodies of mercury with a minimum resistance. A binding post or terminal 20 extends through the wall of the casing above the level of the mercury baths and is connected to the conducting strip 18. A hollow terminal 21 also extends through the wall of the casing above the level of the mercury baths and is connected to the conducting strip 19. A circuit controller 22 is provided to establish and to break the circuit between the conducting strips 18 and 19. Preferably, and as shown, the circuit controller is yokeshaped, it having a pair of arms 23 and 24. which are arranged to operate in the wells 16 and 17 respectively. The circuit controller is pivoted to rock freely on a pivot pin 25, gravity serving to move the arms 23 and 24: downwardly so that their lower ends normally rest on the conducting strips 18 and 19, and the intermediate portion 26 of the circuit controller is in the path of the pins or projections 9 whereby rotation of the wheel or disk 7 in the direction of the arrow in Fig. 6 causes the pins to successively cooperate with the circuit controller to lift the latter into the dotted line position and clear of the bodies of mercury in the baths 16 and 17, and as each. pin passes the intermediate portion 26 of the circuit controller, the latter drops by gravity to the full line position where the lower ends of its arms 23 and 2 1 engage the conducting strips 18 and 19. Obviously, when the circuit controller is elevated by each pin, the circuit between the conducting strips 18 and 19 is broken, whereas when the circuit controller is in its lower position, the circuit controller establishes electrical connection between the conducting strips 18 and 19. The pivot pin 25 on which the circuit controller rocks is carried by a suitable bracket 27, the latter being secured within the casing 10 by a binding screw 28. In the ordinary operation of the instrument, the circuit controlleris actuated by the pins 9 of the breaker wheel, but on some occasions it is desirable to manipulate the controller manually to send special signals over the system. In order to provide for such manual manipulation of the circuit controller, a plunger 29 may be employed, this plunger consisting preferably of a metallic rod which extends through the hollow binding post 21 and having a button 30 on its outer end for manipulation by the finger, and the inner end of the plunger having a head 31 arrangedto cooperate with the under side incense of the circuit controller 22 whereby inward pressure of the plunger will manually raise the breaker sufficiently high to break the circuit between the conducting strips 18 and 19. A spring 32 serves to normally hold the plunger in inoperative position where it will not interfere with the automatic operation of the circuit controller, and an insulating bushing 33 serves to limit the outward movement of the plunger under the action of the spring 32.

The breaker wheel 7 which is rotated by the shaft 8 may be actuated by any suitable means such, for example, as the ordinary clock motor. As shown, the clock motor comprises a drum 34, preferably of insulating material and mounted to turn with a shaft 35, the latter being journaled in the front plate 6 and in the rear plate 36. A

wire or cord 37 is wound upon the drum 34 and has an actuating weight 38 attached thereto. The shaft 35 which carries the drum 34 has a gear wheel 39 mounted loosely thereon, and this gear wheel is adapted to be connected to the shaft 35 by a ratchet and pawl device 40 whereby rotation of the shaft 35 under the action of the weight 38 will cause rotation of the gear wheel 39, but rotation of the shaft 35 in a reverse direction which will lift the weight will be permitted by the ratchet and pawl device while the gear wheel 39 re mains motionless. A cord or wire 41 which is also wound on the drum 34 serves to rotate the drum 34 in. a reverse direction for the purpose of raising or resetting the weight 38. The gear wheel 39 cooperates with a pinion 42, this pinion being fixed to the shaft 8 which carries the breaker wheel, and by this arrangement, rotation of the gear wheel 39 under the influence of the weight 38 will cause rotation of the breaker wheel. The ratio of the gear wheel 39 and the pinion 42 may be varied, but it is generally preferable to employ a ratio whereby the breaker wheel shaft 8 will revolve four times to one revolution of the shaft 35. In order to control-the speed of rotation of the breaker wheel, an escapement 43 is provided, this escapement being mounted on a rock shaft 44 and cor'iperating with an escapement wheel 45, the latter being mount ed on a shaft 46 and carrying a pinion 47 which coijperates with a gear wheel 48 on the breaker wheel shaft 8. The multiplying gearing between the shaft 8 and the shaft 46 enables the vibratory escapement to retard to the proper degree the speed of rotation of the breaker wheel. A weight 49 is fixed to the escapement shaft 44 and serves to retard the vibration of the escapement.

The shaft 35, which is grounded, is connected to a disk50 of brass or other suitable conducting ;1 na-teria 1 This disk 50 is secured to the rear face of the drum 34 and a portion 51 of its periphery is raised so as to project beyond the circumference of the drum 34, while the remaining portion 52 of its periphery is of less diameter than the drum 34 and is below the periphery thereof. A spring or brush 53 is arranged to ride upon the raised portion 51 of the disk 50 or upon the periphery of the insulating drum 34 during a revolution of the shaft 35. This spring or brush is insulated from the base plate 5 by an insulating support 54, and the spring or brush is connected by a binding post 55 and a conductor 56 to a binding post 57, the latter extending through the front plate 6 to the front thereof and being connected by a conductor 58 to the binding post 28, the binding post 57 being insulated from the grounded plate 6. Under normal conditions, the weight 38 is in elevated position, as shown in Figs. 2 and 3. In order to retain the weight in such position but to permit its release and cause operation of the instrument, .a circumferentially grooved plug 59 is attached to the weight or to the cord 8'7, and the base plate 5 is formed with a keyhole aperture 60. A lever 61 is also pivoted at 62 to the under side of the base plate, and this lever has an aperture 63 therein which is sufficiently large to permit the passage of the plug therethrough. When the weight is in its normal elevated position and the plug 59 is fully raised, the lever 61 occupies the full line position shown in Fig. 5 and thus serves to retain the grooved portion of the plug 59 in the narrower portion of the keyhole slot 60 in the base plate 5, the weight 38 being thereby supported in its elevated position, but when the lever 61 is swung into the dotted line position shown in Fig. the plug 59 is moved into the larger end of the keyhole slot 60 and the plug may then pass downwardly through the plate 5 and the lever 61, and the weight 38 is then free to rotate, the drum 34 thereby actuating thebreaker wheel. The weight rewinding cord 41 may extend downwardly through a bushing 64 in the base plate 5 and it may be provided at its lower end with a button or handle 65 bymeans of which it may be pulled downwardly to re wind or reset the weight after the instrument has been operated. The lever 61 is preferably provided with a handle 66 at its forward end, and this handle may be arranged immediately within the glass or other panel'4 so that when the panel 4 has been broken or removed, the handle 66 may be easily reached for manipulation.

A pair of line terminal posts 67 and 68 is provided, these terminal posts being insulated from the base plate 5 by insulating bushings 69 and'TO, and the post 67 is connected to a binding post Tl which is also insulated from the base plate 5 by an insulating strip 72, the binding post 71 being connected by a conductor 73 to a binding post 7 1, the latter being fitted into but insulated from the front plate 6. The binding post 74: extends to the front of the plate 6 and it is connected by a conductor 75 to the terminal or binding post 21. A strip 7 6 of insulating material is provided on the upperside of the base plate 5, and a conductor strip 77 overlies the insulating strip 7 6 and is connected to the terminal post 68. The conductor strip 77 is connected to a binding post 78 which is fitted in but insulated from the front plate 6, this binding post 78 being connected by a conductor 7 9 to the termi nal 20. Each box or instrument is provided with a telephone jack which is bridged across the line terminals 67 and 68 whereby a telephone may be introduced into the line circuit of the system, the shunt or bridge circuit of the telephone aclr being open under normal conditions when the telephone is not in use. The telephone jack may be made in different ways. As shown, the conductor strip 77 provides one terminal or contact 80, and a plate 81 connected to the terminal 67 provides the cooperating terminal or contact 82, the front plate 6 being provided with a socket 83 through which the telephone plug may be inserted, and the telephone jack is in position to cooperate with the respective terminals of the telephone plug when the latter is inserted into the socket. made in different ways, although it is preferable to use a telephone plug of a type similar to that commonly used in connection with telephone systems. The plug shown in the present instance in Fig. 12 comprises a handle 84 having a conducting sleeve 85 projecting forwardly therefrom to a point near its end, an insulating bushing 86 which is.

fitted within the conducting sleeve, and a central or inner terminal or electrode 87, the wires 88 and 89 of the telephone being connected, respectively, to the conducting sleeve 85 and the inner terminal 87, and when the plug is inserted into its socket, the conducting sleeve 85 will contact with the terminal 82 of the jack, while the inner terminal 87 of the plug will contact with the terminal 80 of the jack. lVhen the plug is introduced into the jack,.the telephone at the box or instrument is introduced into the fire alarm system in shunt therewith. According to the present invention, a telephone is also provided for the central or receiving station, this telephone embodying the usual transmitter 90 and receiver 91. and, in addition, a local battery 92, the transmitter and battery of the telephone being connected in series with one another, and when the telephone plug is inserted in the telephone jack at central The telephone plug may be station, the local battery of the telephone will be connected in series with the battery or source of energy for the fire alarm system, thus overcoming the increased resistance offered by the telephone system and the relay 105 at the central station.

The battery B of the main circuit may at times get low or weak so that the current of the closed circuit is not much more than sufficient to keep the relay 105 energized to such an extent as to maintain the armature thereof in an elevated position. Should an attempt be made to use the telephone under such conditions, without the local battery 92, the current from the battery B would not be sufficient to overcome the extra resistance introduced into the circuit and at the same time keep the relay 105 sufficiently energized. The battery 92 supplies a sufiicient amount of current to overcome the extra resistance introduced into the circuit, so that there is no danger of the relay 105 being closed because the current from the battery B is not suificient to overcome the increased resistance of the telephone circuit and keep the relay properly energized. Furthermore, the local battery 92 is necessary for enabling the telephone to be used when the main line is broken, as at the point X in Fig. 10, and a grounded circuit is utilized for the fire alarm. The switch S is then in the dotted line position indicated by Fig. 10, with the two arms thereof moved into engagement with the contact points 110 and 101. A telephone circuit is then established through the wires 111 and 100, without interfering with the grounded main line circuit. The current for the telephone circuit is then supplied by the local batteries 92, and the telephone would be entirely inoperative if it were not for the battery 92. This enables a lineman to communicate with the central station and instruct the operator to move the switches S and S back to their normal positions after the line has been prepared.

As shown in Fig. 10, a telephone jack J is provided at the central station which is adapted to receive a telephone plug P of the central station telephone, the jack J having its terminals connected in series with the line wire 103, and a circuit closer K arranged in shunt with the jack serves to complete the line circuit when the telephone is not in use. Preferably, and as shown, a spherical head 93 is provided which is adapted to enter between and to connect the terminals of the circuit closer K while the telephone plug is not in position, this head being carried on an arm 94: which latter is pivoted at 95 to a suitable support 96. lVith this arrangement, the head 93 will normally connect the terminals of the circuit closer K, but when the telephone is used, this head 93 is disengaged from the circuit closer Kafter the telephone plug has been inserted, the telephone being connected in series with the fire alarm system and thereby completing the circuit or such system.

Perferably, and as shown, a grounding key 97 is provided for a purpose that will hereinafter appear, this key comprising a spring which is secured at one end and electrically connected to the line terminal 08, and its opposite end is normally adjacent to but separated from the under side of the base plate 5, upward pressure on the free end 01 the key, however, serving to engage it with the base plate, thereby grounding the side of the system to which the terminal 08 is connected.

A fire alarm system embodying the present invention and having a plurality of instruments connected therein is shown diagrammatically in Fig. 10. In this diagram, A and B designate, generally, two of the instruments of the system, 0 represents diagrammatically the central or receiving station, and T and T represent diagrammatically telephones adapted to be introduced into the system at a box or instrument and at the central. station, respectively. The circuit of the system, including the various in struments, is normally closed and receives energy from a main battery B, one terminal of this battery being connected by a conductor 98 to one blade 99 of a double switch S. A conductor 100 leads from the contact 101 of the switch S to the box A through which the circuit of the system is normally closed, and a conductor 102 leads from the box A to the box or instrument B, this conductor 102 leading'to the line terminal 68,,the conductor 77 leading from the terminal 68 to the binding post 78, this binding post being connected by the V conductor 79 to the terminal 20 of the circuit controller. The terminal 2033 connected to the conducting plate 18 submerged in the body of mercuryin the well 16, and the other conducting plate 19 submerged in the body of mercury in the well His connected to the binding post 21. The binding post 21 is connected by. the conductor to the binding post 74:, and the latteriis connected by the conductor 73 to the line terminal 67,

The line wire l03leads 'fr mtlie line terminal 67 to. such other instruments as may be included in thesystem, throughthecircuit closer K, and it terminates at the line terminal 104 of the relay 105, the'latter being locatedat the central or'receiving station. The other. line terminal 106 of the relay is connected by theconductor 107 to the opposite terminal of the main battery B. The instrument B is adapted to be connectedto the ground G through the frame or metallic parts of the instrument which is designated diagrammatically in Fig. 10 as a conductor- 1O8'which-leads -to the shaft 35,

the ground connection when "completed being made through the disk 50, the brush or spring contact 53, the conductor 56, binding post 57, conductor 58, and the terminal 28, the latter being electrically connected to the circuit breaker 22. The instrument A is provided with a ground Gr which corresponds to the ground G of the instrument B. A main ground G isprovided for the system, but this ground normally is not used. To enable the system to be grounded when such is desirable, the ground conductor 109 leads to a contact 110 which is adapted to be engaged by the blade 99 of the switch S, when this switch is shifted into the dotted line position shown in Fig. 10, one terminal of the battery B being then grounded through the conductor 98. An additional conductor 111 may also be extended from. the line terminal 104 of the relay to the other blade 112 of the switch S, this blade of the switch being connected by the member 113 to the blade 99 whereby these blades will move in unison, andwhen the switch Sis in its normal position, the conductor 111 will not be included in the system, but when the switch S is shifted to the dotted lineposition in Fig. 10, the conductor 111 will be connected through the terminal 101 to the line'wire 100. The local terminal 114 of the relay is connected to one terminal of a local battery B while the other local terminal 115 of the relay may be connected to the conductors 116 and 117 which are connected respectively to a bell 118 and a suitable register or" indicator 119, the other terminals 120 and 121 of the bell and register respectively being connected by a conductor 122 to the other side ofthe local battery B The local circuit of the relay is "of a type whereby the bell, register, or other indicators or instruments connected therein will becaused to act when the normally closed line circuit of the relay is, broken, it being understood that the line circuit of thesystem is normally closed. The telephone at the central station, accord ing to the present invention, is introduced in series in the use circuit of the system,

and, furthermore, thefpolarityof thetel'etive sideof the battery'92 will'be' connected to the negative side of the'm'ain battery B,

i that "is to say, the telephone}batteryjllfzjis connected series with the' main battery B whereby the telephone battery'j92 will supplement the energy supplied to the lsystem by the main battery.

In order to provide for operation of the system using the ground as'a return, a second relay 123'is preferably used at the central station, the main circuit terminal 124 of which is connected by a conductor 125 to I the'local circuit terminal 1150f the' relay 105 and the other main circuit terminal 126 of which is connected to a contact 127 of a switch S, the blade 128 of this switch being connected to the conductor 122 leading from the positive side of the local battery B of the relay 105, and the blade 129 of the switch S is connected by a conductor 130 to the local terminal 131 of the relay 123, the other local terminal 132 of the relay 123 being connected by a conductor to the positive side of a local battery B and the other side of this local battery being connected to the local terminal 115 of the relay 105.

By using a second relay connected as described, the bell and register will act in the same way when the ground is used for the return of the main line system as they act when the all-metallic line is used, in view of the following mode of operation 2-VVhen the line circuit of the system is broken, the local circuit of relay 105 will be closed. By shifting the switch S from the full line to the dotted line position (Fig. 10) the main circuit of relay 123 is introduced into the local circuit of relay 105 and the local circuit of relay 123 will then be open. Any signal or alarm coming over the system from an in-- strument connected therein will then cause the bell and register to operate in response to the signal just as the relay 105 would.

cause operation of the bell and signal in the normal condition of the system.

When the main line is broken and a grounded circuit is used for the alarm, this grounded circuit is normally an open circuit instead of a closed circuit, as in the previous instance. The grounded circuit is normally broken by reason of the fact that the contact spring; 53 engages an insulated portion of the disk 50. Through these conditions the relay 105 is normally closed instead'of open. This would result in a continuous indication on the register 119 and a continuous sounding; of the gong 118, were it not for the fact that the second relay 123 is rende ed operative by the shifting of the swi ch S into the dotted line positionshown by Fig. 10. It will thus be seen that when the system operates upon a grounded circuit .the relay 1.05 is normally closed and the relay 123 normally open. l Vhen an alarm is sounded at any one of the stations, the rotation of the disk 50 at "the particular station brings a metallic portion thereof into engagement with the contact spring 53 and closes the grounded circuit so that the alarm can be turned in over the grounded circuit.-

scribed, briefly, as follows :Normally, the switches S and S occupy the positions shown by the full lines in Fig. 10, and hence the main battery of the system will not be grounded, and the actuating weights of the various instruments in the system will be in elevated position and retained in such position by the releasing; ever 61 of each instrument. Also, the toothed wheel 7 of each instrument will occupy such a position relatively to its respective circuit breaker 22 that, upon the commencement of the rotation of the toothed wheel, the circuit breaker will begin its operation. of sending an alarm or signal corresponding to the number of the particular instrument. 'While the instruments are inactive, as is normally the case, the circuit is normally closed throughout the system as follows :Starting with. the main battery B, the current passes over the conductor 98, the switch blade 99, conductor 100, through the instrument A, over the line conductor 102, terminal 68, conductor 77 to binding post 78, over the conductor 79 to terminal 20 to the conducting plate 18 submerged in the mercury in the well 16. thence up the arm 23 of the circuit breaker 22, thence down the arm 2 1 of the circuit breaker to the conducting plate 19 submerged in the mercury con ained in the well 17, thence to the terminal 21. over the conductor 75 to the bindin post 74:. thence over the conductor 73 to the binding post 67, thence over the line conduc or 103 and the circuit closer K therein to the line terminal 1041 of the relay th ough the line circuit of the relay to the line terminal 106 of the relay. and thence by the conductor 07 to the return side o the main battery B. In order to send a signal or alarm from any instrument, it is only necessary to b ak or remove the panel 4 of the pa ticula box or instrument and then push he han e 06 of the leve 61 toward the left n Fin". 1. This ope ation releases he blue 59 at a hed to the wei ht co d 37 nd the we ght 38 then acts u on the drum 34 to otate the shaft 35. Motion from the shaft 35 is transmi ted to the shaft 8. and the toothed whe l 7 is thereby caused to revolve. During the reyolying motion o the too hed wheel 7.. the

tee h or nins 9 thereon successively en age and lift. he circuit bre ker 22 to the dot ed line osition shown in Fiq. 6. each ninafter passingthe ci cuit breaker nermittino; the latter to drop b avity to ts norma ower position. as shown by he u l lin s in F151. 6. 1

one of the pins or teeth, and this breaking by the circuit breaker of this instrument and the re-closing of the circuit between the breaks actuates the relay 105, causing the signals or indicators contained in the local circuit thereof to respond to the signal transmitted from the instrument, After the sending of the signal from the instrument has been completed, the normally closed line circuit of the system is restored and any other instrument in the system maybe'similarly set into operation. In the normal con dition of each instrument, there is no ground connection with any of the instruments, as the brush or spring contact of each instrument normally rests on the insulating drum 3 1. However, upon the releasing of the instrument, the grounding disk 50 of the instrument comes into engagement with the brush or spring contact 53, and a ground connection is then established for the instrument in operation, the groundbeing completed from the terminal 20 through the circuit breaker '22, the terminal 28, conductor 58, binding post 57, conductor 56, the spring contact- 53, the disk 50, and the frame of the instrument which is indicated diagrammatically in Fig. 10 as the conductor 108; By moving the switches S and S, which are located at the central or receiving station, to the dotted line positions, the main battery B will be grounded at one side, and a signal could be obtained from the instrument using the ground as one side or a part of the cir cuit, thus enabling the instrument to transmit a signal in the event that the line circuit of the system is broken or is undergoing repairs. In such case, the current would pass from the main battery B over conductor 98, switch blade 99, contact 110 and conductor 109 to the ground G, thence from the ground P of the instrument B over the conductor 108, shaft 35, disk 50, brush or contact conductor 56, binding post- 57, conductor 58, terminal 28, the circuit breaker 22, the conducting strip or plate 19, terminal 21, conductor 75, binding post 74, conductor 7 3, through the terminals 67 and 80 and over the line wire 103 to the terminal 104 of the rela through the line circuit of the relay 105 to the line terminal 106 thereof, thence over the conductor 107 to the return side of the battery. Such would be the operation if the line circuit were broken at the point X between the instruments A and B and a signal were sent from the instrument B. It the break occurred at the same point as before, but instrument A were set into operation, the current from the main battery 13 would pass, as before, to ground G, thence from ground G to instrument A, thence through the grounding and circuit breaking devices of that instrument to the line wire 100, returning through the wire 111 and the relay 105 to the return side of the battery.

It will be understood that a break in the all-metallic line of the system will be indicated at the central station by a continuous indication of the register 119 and by a continuous sounding of the gong 118, and the attendant will then shift the switches S and S to their dotted line positions (Fig. 10)

pending repair oi the line.

lVhile the main line system is grounded, and the switch S occupies the dotted line position (Fig. 10), the bell and register which are then connected in the local circuit of the relay 123 will respond to the signals or alarms coming over the line in the same manner that these devices respond to such signals when the all-metallic line of the system is unbroken and the bell and register are controlled by the relay 105.

The key or plunger 29 may be used by the fire department official or other attendant as a means for manually sending a special signal or alarm over the system, in which case the circuit controller 22 would be caused to rise and fall manually to break and reestablish the line circuit, the signal being sent over the line in a manner similar to that where the signal is transmitted automatically by operation of the signal wheel 7. The key 29 is also used to send a pre-arranged signal over the line from any instrument or box to the central station to notify the central station operator that it is desired to use a telephone on the line. In using a telephone on the line, the attendant at the box or instriunent inserts his telephone plug into the jack 83, thus bridging the terminals of his telephone over the line terminals 67 and 68, and the central station operator inserts the plug of his telephone into the jack J and opens the circuit closerK. The key 29 is then pressed up to render operative the line circuit through the telephone at the instrument by opening the short circuit between the jack terminals and the key is held up while the telephone is in usea When the telephones are to be removed from the system, the pressure upon the key 29 is released, allowing the circuit controller 22 to complete the line circuit, and the telephone plug at the instrument is removed from its jack and the central station operator closes the circuit closer K and then removes the plug of the telephone at the central station from its jack J. The grounding key 97 may also be used to send a special signal over the system from the respective instrument or box, while the switch S is in the dotted line position (Fig. 10), and this key may also be used in testing the system.

By providing a circuit controller having its contacts submerged in baths of mercury, the engaging surfaces of such contacts are, under ordinary conditions, covered and protected from the corroding influences of gases and other elements which, it has been found, attack the ordinary exposed contacts as heretofore used and thereby render the operation of a system of this character uncertain and hence unreliable. Therefore, certainty and reliability in the operation of the system is insured by providing, at all times, good conductivity between the working or signaling contacts. This result is at tained by the presentinvention and yet operating movement of the working contact is not impeded, as the mercury offers negligible resistance to the movement of the working contact.

By providing a normally closed circuitsystem which, under ordinary conditions, operateswithout a ground return to its main battery or source of energy, there is practically no opportunity for damage to or in terference with the operation of the system by crossing of its wires with those of other circuits. Furthermore, by connecting the telephone in series in the line circuit of the system, satisfactory use may be made of the telephone, as compared with such systems which employ a ground return, for, in such latter systems, interference by other circuits using ground returns impairs or prevents the use of a vtelephone.

I claim as my invention 1. In an alarm mechanism, circuit breaking means comprising a closed casing, a movable circuit breaking element housed within the closed casing, contacts cotiperat ing with the circuit breaking element, a motor driven actuator housed within the casing for mechanically operating the circuit breaking element, and means operable from the exterior of the casing for manually moving the circuit breaking element independently of the before-mentioned actuator.

2. In an alarm system, circuit breaklng means comprising a closed casing, a freely gravitating circuit breaking element in the casing, contacts cooperating w1th the circuit breaking element, a motor driven actuator for mechanically operatlng the circuit 3 breaklng element, and normally lnoperative manually controlled means for lifting the circuit breaking element independently of the before-mentioned actuator.

3. In an alarm mechanism, circuit breaking means comprising a substantially air tight casing of insulating substance, a freely gravitating circuit breaking element in said casing, a mercury bath within the casing to contact with said breaking element, an axis wholly within the casing and on which the breaker element is lightly pivoted, and a motor driven actuator wholly within the casing and operatively associated with the breaking element.

a. In an alarm mechanism, circuit breaking means comprising a yoke shaped conducting member, an axis on which said memher is freely pivoted for gravitation, contact means arranged for cooperation With the sides of said member, and a motor driven rotary actuator constructed to engage the portion of the conducting member intermediate its sides to lift and drop the said memher, a predetermined number of times.

5. In fire alarm mechanism, circuit breaking means comprising a substantially air tight casing of insulating substance, an actuator, a freely gravitating circuit breaker in said casing, a mercury bath in the casing to contact with said breaker, an axis wholly within the casing and on which the breaker is lightly pivoted, said actuator being wholly in the casing, means to mechanically operate said actuator, and means operable from a point exterior to the casing for manually operating the breaker.

In testimony whereof I have hereunto set my hand in presence of two subscribing wit- HBSSBS.

MANIOUS GARL.

Witnesses:

J. I. BACHTEL, WM. H. BIGLER.

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