US2080136A - Telephonic alarm system - Google Patents

Description

May 11, 1937.

J. JOHNSON TELEPHONIC ALARM SYSTEM Filed Dec. 21, 1934 9 Sheets-Sheet 1 INVENTOR. John M Johnson J64. F?

ATTORNEY.

May 11, 1937. J. M. JOHNSON 2,080,136

TELEPHONIC ALARM SYSTEM Filed Dec. 21, 1934 9 Sheets-Sheet 2 II II .g\ & fi

I L}- Q e 5% g INVENTOR. John M Johnson vb l ATTOEYS.

Mayll, 1937. J. M. JOHNSON 2,080,136

TELEPHONIC ALARM SYSTEM Filed Dec. 21, 1934. 9 Sheets-Sheet 3 IN V EN TOR. .j0/7/7 MJO/vnsm BY f ATTORNEYS.

May 11, 1 937. J. M. JOHNSON TELEPHONIC ALARM SYSTEM 21, 1934 9 Sheets-Sheet 4 Filed Dec INVENTOR Jo/m A7. Job/7500 BY Jar Z ATT RNEYS.

May 11, 1937. 'J. M. JOHNSON TELEPHONIC ALARM SYSTEM Filed Dec. 21, 1934 9 Sheets-Sheet 5 x/ $9 $7 m Q W L Q7 $7 p 3L Q) h K q C IN V EN TOR. J0/2/7 MJa/wzsan A TTORN E YS.

May 11, 1937;

J. M. JOHNSON TELEPHONI C ALARM SYSTEM Filed Dec, 21, 1934 9 Sheets-Sheet 6 IN V EN TOR. John M Johnson BY WW. K Q zzlzL z ATTORNEYS.

May 11, 1937.

J. M,-JOHNSON TELEPHONIC ALARM SYSTEM Filed Dec. 21, 1934 9 Sheets-Sheet 7 im y 3PM Q kV/K I N V EN TOR.. John M Johnson BY JAMWQW ATTORNEY.

y 1937. J. M. JOHNSON 2,080,136

TELEPHONIC ALARM SYSTEM Filed Dec. 21, 1934. 9 Sheets-Sheet 8 INVENTOR.

John M Johnson ATTORNEY.

May 11, 1937. J. M. JOHNSON TELEPHONIC ALARM SYSTEM 9 Sheets-Shed 9 Filed Dec. 21, 1934 IN VENTOR. John MJo/mson J mw A TTORNEY.

Patented May 11, 1937 UNITED STATES PATENT OFFICE 4 Claims.

My invention relates to a telephonic alarm system.

The telephone has become a commercial and social necessity. It is found in every business house, factory, ofiice, and in a great proportion of the homes throughout; the United States. A net of telephone systems is spread throughout the country.

Despite the ubiquity of telephone systems, we find independent telegraphic fire and burglar alarm systems installed in various cities. This entails a certain amount of waste, inasmuch as there is duplication of wiring and transmission lines which might be saved if the telephone lines could be used for the transmission of fire and burglar alarms. The necessity of laying and installing separate wiring systems for fire and burglar telegraph alarm systems has made the service of such alarm systems a matter of considerable expense so that this service is, not made use of as generally as it should be. That this is a fact is attested by the huge fire loss which occurs in the United States annually. This fire loss has been estimated as in excess of five hundred million dollars each year. Not only is there a loss of property as a result of fires, but it is estimated that fifteen thousand people lose their lives due to fire. The increase in the depredations occasioned by the criminal classes is noticeable within recent years. The loss of property through burglary of business establishments, warehouses and private homes is becoming larger.

It will be seenthat an alarm system for protection against fires and burglars, which could use the telephone systems already existing, would enable fire and burglar alarm service to become available at much less expense than is at present the case. The extension of fire and burglar alarm systems would greatly reduce the loss of life and property through fire and burglary. Most fires start as small ones. If the fire department of a locality were notified within due season, fires could be quickly extinguished before any great damage could be done. Likewise, many homes, warehouses, and business establishments are burglarized during the absence of their owners. Due to the fact that it is now common practice in many localities to employ patrol cars, equipped with radio receivers, it is possible for police oficers to arrive at a given locality within a short interval of time after being notified through a central police radio broadcasting station. i Telephone companies exist primarily for the purpose of telephonic communication. The de vices and instruments used by the telephone companies are designed for this end. Any device which would interfere with the telephone service will necessitate a change in the telephone installation, per se. It cannot be used to transmit fire and burglar alarms as it would impair the primary function of the telephone system. One object of my invention is to provide an alarm system, which may be either a burglar or fire alarm, over an ordinary telephone system.

Another object of my invention is to provide an alarm system in which no change is made in an ordinary telephone system or in any of the instruments used by telephone companies.

Another object of my invention is to provide an alarm system which is self-supervised, that is, one which will signal if the system is deranged. Another object of my invention is to provide an alarm system which will give an alarm even though the system is deranged.

Still another object of my invention is to provide an alarm system which may be used with any of the known telephone systems such as the common battery type, the magneto type, or the automatic telephone type.

Other and further objects of my invention will appear from the following description.

In the accompanying drawings which form part of the instant specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views;

Figure 1 is a'diagrammatic view. showing my alarm system connected as a fire alarm .with a common battery type telephone system.

Figure 2 is a diagrammatic view of a system as shown in Figure 1,v sending a trouble alarm.

Figure 3 is a diagrammatic view or the system shown in Figure 1 sending a fire alarm.

Figure 4 is a diagrammatic view of a fire alarm system in combination with a magneto telephone system.

Figure 5 is a diagrammatic View of the system shown in Figure 4 sending a trouble alarm.

Figure 6 is a diagrammatic view of a fire alarm system in combination with an automatic telephone system.

.Figure 7 is a diagrammatic view of the alarm system shown in Figure 6 sending a fire alarm.

Figure 8 is a diagrammatic view of a burglar alarm system in combination with a battery telephone system.

Figure 9 is a perspective view of a room equipped with one form of a system of thermostats designed to operate the fire alarm systems of my invention.

Figure 10 is an enlarged view partly in section, showing the circuit breaking means which are operated thermostatically.

Figure 11 is a sectional view taken on the line of Figure 10.

Figure 12 is an enlarged perspective view of a detail.

Figure 13 is a perspective 'view of the relay coils used in carrying out my invention.

Figure 14 is a sectional view of the relay coil shown in Figure 13, with the winding removed.

In general, my invention contemplates the provision of a pair of switches such that, when either one of them is closed, a microphone or transmitter is connected to the main line wires of a telephone leading to the district exchange or central exchange of a telephone system. At the same time, provision is made for calling the operator's attention to the fact that a micro phone or transmitter is placed across the line. In the case of a common battery system, merely placing a microphone across the line will call the operator. In the case of a magneto installation, a source of potential is provided for calling the operators attention and, in the case of an automatic telephone system, provision is made for dialing the operator. Simultaneously with the connecting of the transmitter with the central station, a bell or buzzer is made to sound when each switch is closed. The closing of one switch only will sound one bell or buzzer. The closing of both switches will sound two bells or buzzers. The bells or buzzers are made to give different tones or sounds. The bellsor buzzers are placed in proximity to the microphone so that, when the operator answers the call, she will hear either one bell or buzzer, or two bells or buzzers ringing, depending on whether or not one or both switches or relays are operated. In general, one bell or buzzer will indicate a trouble alarm, while the sounding of both bells or buzzers will ind cate a fire alarm. In event it is desired to have both fire and burglar alarm systems, a gong or a different sounding instrumentality may be employed to indicate a burglar alarm. The operator is provided with a directory for the particular exchange to which the telephone equipped with the alarm system of my invention is connected. By reference to the directory, the location of the trouble, fire or burglar alarm is ascertained. The operator then calls the fire or policehepartment, as the case may be, and gives the information.

More particularly referring now to Figure 1, a pair of lines I and 2 are connected to a source of potential which may be the ordinary house current or, if desired, to a battery. In the figure, lines I and 2 are connected to ordinary alternating current, 110 volt potential, such as found in most cities. The primary coil 3 of transformer 4, and the primary coil 5 of transformer 6 are connected across lines I and 2. Extending through an area to be protected against fire, for example, I provide a plurality of thermostats I, each of which carries a pair of fusible links 3 and 3. All of the links 3 are connected in series with a conductor Hi, the ends of which are connected respectively to the winding of relay II ,and secondary coil |2 of transformer 4. The

fusible links 3 are connected in series with a conductor' l3, the ends of which are connected respectively to the winding of relay l4 and the secondary coil I! of transformer 3. The other ends of secondary coil 5 and the windings of relay 4 are connected by a conductor l6. Similarly, the other ends of the winding of relay H and secondary coil I 2 are connected by conductor H. The construction of relays II and H can be readily seen by reference to Figures 13 and 14 in which the winding is dlsposedin the space l3 around a core l3, whiElT is screw threaded at its upper portion 23 as can readily be seen by reference to Figure 14. A nut 2| is adapted to be screwed upon threads 23 such that it will adjust the position of core l3. An armature 38 is adapted to be held in the position shown in Figure 14, when the winding is energized. The lower portion of armature 33 is provided with a groove 22 in which is adapted to be seated a rubber washer 23. The magnetic pull of the core |3 seats the washer 23 against the lower end plate 24 of the relay. It will be'noted that, in the assembled position, an air gap 23 is provided to prevent humming or chattering between the-core l3 and The terminal block of the telephone system is 25 indicated by the reference numeral 26. To bus bar 21 is connected one of the main line wires 23 which leads to the central station. To bus bar 23 is connected the other main line wire 33 leading to the central station. When it is desired to make a telephone call, it being remembered that Figure 1 illustrates the common battery type of telephone system, the receiver 3| is lifted from its hook, thus placing the transmitter or microphone 32 across the line in series with coil 33 of the transformer and also connecting the receiver and coil 34 in proper relationship to the primary coil 33 of the transformer. The lifting of the receiver 3| allows the hook 35 to contact terminals 35 and 31 and thus completes the circuit to the common battery through main line wires 28 and 30, which gives a signal at the central station notifying the operator. It will also be noted in Figure 1 that, while current is flowing through the winding of relay l4, armature 33 will be held in the position shown in Figure 1. Similarly, while current is flowing through the winding of relay armature 39 will be held in the position shown in Figure 1. Disposed beneath armature 33 and adapted to be actuated by the weight thereof is a double contact switch 40. One of the members of the switch carries a contact point 4|. The other member of the switch carries a contact point 42. These switch members may be made of light, resilient material or may, if desired, be pivoted. Contact point 4| is adapted to contact contactpoint 43, while contact point 42 is adapted to contact contact-point 44. Similarly disposed under armature 33 is a double contact switch 45 having a pair of resilient members 46 and '41 carrying contact points 43 and 43 respectively. These contact points are adapted to make contact with contact points 53 and 5|. Contact point 43 is connected by conductor 52 to one terminal of a battery 53, the other terminal of which is connected to a bell 54 by conductor 55.

The contact point 4| is connected to bell 54 byare electrically connected to conductor 62 by conductors 63 and 64, respectively. Conductor 62 is connected to one terminal of a microphone or transmitter 65. The other terminal of the microphone is connected by conductor 66 to bus bar 29. Both contact points 44 and i are electrically connected to conductor 61 by conductors 68 and 69 respectively. Conductor 61 is connected to bus bar 21.

It will be seen by reference to Figure 1 that current always flows through both primary coils 3 and 5. It will be understood, of course, that if a battery is employed instead of transformers, that the terminals of the windings of relays II and [4 will be connected to the source of potential. It will be observed further that the circuit through relay winding I I contains the fusible links 9, the conductor l8, and the secondary coil l2 in series and that normally current is flowing through this circuit. Similarly, it will be noted that there is a circuit comprising secondary coil l5 of transformer 6, conductor l3, the fusible links 8, the winding of relay l4 and conductor IS in series. Current normally flows through this circuit. While current flows through the two circuits just mentioned as shown in heavy lines in Figure 1, armatures 38 and 39 are held in the position shown in the figure.

Referring now to Figure 2, it will be noted that the circuit comprising the fusible links 9, con-- ductor i8, secondary coil l2, conductor I1, the winding of relay l I, and conductor I8, is broken at 18 in conductor It], thus deenergizing the winding of relay II. It will also be observed that the circuit through the winding of relay I4 is un broken. The winding of relay ll, being deenergized in Figure 2, the armature 39 is shown in its dropped position, spreading members 46 and 41 and causing the contact points 49 and 5|, as well as contact points 48 and 58 to touch. It will ae seen that current is now permitted to flow from the common battery at the central station ;hrough conductor 28, through bus bar 21, zhrough conductor 61, through conductor 69, ;hrough contact points 5| and 49, through coniuctor 64, through conductor 62, through the nicrophone 65, through conductor 66, through )US bar 29, through conductor 30, back to the :ommon battery. It will be observed that this low of current will operate a signal at the cen- ;ral station. The microphone 65, .too, will be alaced across the line wires 28 and 30. Likewise, :urrent will flow from the battery 51 through :onductor 58, through contacts 58 and 48, hr'ough conductor 6|, through the windings of iell 59, through conductor 60, back to the bat- ;ery causing the bell 59 to ring. Bell 59, as has een observed hereinabove, is of a different tone zhan bell 54. The operator, on answering the Main exchange Telephone number Owner v Address 1427 Walnut Street. 2416 Grand Avenue. 1014 Baltimore Ave. 1322 McGee St.

1528 Wyandoite St.

Sterling Produce Co..

Dr. 0. L. Stevens..-"

Robinson's Clothin B. H. Hill (residence A. J Johnson (residence.

The operator then calls the repair department and informs them that the alarm system at the name and address which he learns from the directory needs attention.

If, in the interim, a fire should break out at a place which has already sent in a trouble alarm, or in event a fire break out, the heat of the fire will fuse one or more pairs of links 8 and 9 as shown at 1| and 12 in Figure 3. When this occurs, both relays II and I4 will be deenergized, allowing both armatures 39 and 38 to drop and take the position shown in Figure 3 in which it will be observed contact 49 is closed with contact 5|, contact 48 is closed with contact 58, contact 4| is closed with contact 43, and contact 42 is closed with contact 44. The placing of the microphone 65 across the line and the signaling of the operator is performed in the manner just described by either the closing of contacts 49 and 5| or the closing of contacts 42 and 44. It will be observed that, when contacts 42 and 44 touch, current flows from the common battery at the central station, through line 28, through bus bar 21, through line 61, through conductor 68, to contact point 44, through contact point 42, through line 63,. to conductor 62, which leads to one terminal of the microphone 65. Current continues through the microphone 65, through conductor 66, to bus bar 29, through line 38, to the other terminal of the common battery. Likewise, current will fiow from battery 53 through conductor 52, through contact point 43, through contact point 4|, through conductor 56, through the winding of bell 54, through conductor 55 to the other side of battery 53, thus completing the circuit through hell 54. When the operator plugs in, in answer to the signal, she will instantly hear the ringing of two bells of different tone in unison. This she knows is the fire alarm signal. Consulting the directory, the operator asoertains the location of the fire and then calls the fire department and gives them the location of the fire.

Referring now to Figure 4, it will be noted that the magneto type of telephone switch is shown. In this system when it is desired to call, the operator must be signaled by energizing the line wires 28 and 38 by actuating a magneto 14. While the hook 35 is down, the magneto 14 is placed across the line by means of conductors 1'5 and 16 so that, when it is actuated with the hook down, the operator will receive the signal. When the receiver 3| is lifted from the hook 35, the transmitter 32 is placed across the line and the magneto is disconnected due to the fact that the hook 35 is lifted from contacts 11. In order to call the operator, therefore, with a magneto type system, some means must be provided for energizing the main line wires 28 and 38, which lead to the central exchange. For this purpose, I provide battery 80 having one terminal thereof connected to contact point 8| and the other'terminal thereof connected to conductor 66 which leads to bus bar 29, to which line wire 38 is connected. Conductor 28 is connected to bus bar 21 to which is also connected conductor 61 which is in turn connected by conductor 82 to the contact point 83 which is carried by a non-conducting arm 84, which is pivoted to base 85 at 86. Arm 84 is provided with a foot 81, adapted to seat in a notch 88 of a cam 89 which is mounted on a shaft 99 to which is keyed a pinion 9| which meshes with a gear wheel 92driven by a spring 93. Arm 84 is also provided with a projection 94 which carries a follower 95 which bears against a cam 99 formed upon an armature 91 of solenoid 98. A spring 99 urges the arm 84 so that contact point 83 is separated from contact point 8|. A small battery I80 has one terminal thereof connected to the winding of electromagnet 98 by conductor NH. The other terminal of the battery Hill is connected by conductor I82 to conductors 64 and 83, which are connected to contact points 49 and 42, respectively. One terminal of the microphone B is connected to conductor 62, which is connected to the other end of the winding of electromagnet 98.

Referring now to Figure 5, if the alarm system should become deranged, as for example by the breaking of conductor ID at I05, so that the circuit through the winding of relay II is broken,

tion, through the central station, through line wire 28, through bus bar 21, through conductor 61, through conductor 69, through contact point 5|, through contact point 49, through conductor 84, through conductor I02, to the other side of battery Hill. This current flow is no greater than that occasioned by the usual cells I08 of the magnetophone system, and is not suilicient to operate the signal at the central station. The current flow, however, is suiiicient to energize the electromagnet 98 such that the armature 91 thereof is raised. The upward motion of the armature 91 moves cam projection 98 past follower 95, thus pivoting the arm 84 around its pivot 86 against the action of spring 99. This motion lifts the foot 81 out of notch 88 and permits the spring 93 to actuate gear wheel 92 to rotate pinion 9|, to turn shaft 99 and cam 89 in the direction of the arrow. At the same time, it will be observed that contact point 83 will touch contact point 8|, completing the circuit from battery 80 through conductor I01, through contact 8|, contact 83, conductor 82, conductor 61, bus bar 21, line wire 28, to the signal at the central station which is operated by the current flow, through line wire 30, through bus bar 29, through conductor 88, through conductor I08, to the other side of battery 89. As soon as the notch 88 again comes in contact with foot 81, the spring 99 will urge the foot into the notch, thus stopping the rotation of cam 89 and, at the same time, permitting the contacts 8| and 83 to separate, thus breaking the circuit of battery 80. It will be observed that battery 88 is directly across the microphone as well as the line, while battery I09 is in series with the microphone. The operator, on answering the signal, will hear the tone of bell 59 which is being transmitted through microphone 85. Hearing only one tone, the operator will know that there is a derangement in the alarm system at the particular location which is found from the directory hereinabove described. It will be understood, of course, that each district exchange has its own directory.

If a fire should break out, such that fusible links 8 and 9 are melted to interrupt the circuits through both relays, the operator will hear they ringing of bells of different tones and will know .that a fire alarm is being sent, the operation of relay l4 being the same as hereinbefore described. The action of either relay l4 or II is such that the operation just described will take place. If relay 88 operates instead of relay 88 to send a trouble alarm, the current flow will be through conductors 88 and 88 instead of conductors 84 and 89.

Referring now to Figure 6, in which a diagrammatic representation of the alarm system of my invention in combination with an automatic telephone system is shown, it will be observed that, in an automatic telephone, when the receiver 8| is lifted from its hook 85, the transmitter 82 is placed across the line. This compleies the circuit through line wires 28 and 88 to the district exchange and energizes a line relay which closes circuits in the central exchange as is well known to the art. Upon dialing, the first movement of the dial moves a cam permitting contacts 8 and 4 to close, thus shunting the transmitter 82 and the receiver from the line. Upon dialing a number, the cam ||2 makes and breaks the circuit by opening and closing contact points 8M and 882. The making and breaking of the circuit actuates the selector switches or other selecting devices at the central exchange, thus connecting the subscriber with the desired station.

It will be seen, therefore, that, in order to accomplish one of the objects of my invention, namely to provide an alarm system which may be installed without in any way changing the existing telephone system, the dialing action just described must be automatically duplicated by my alarm system.

Referring now to Figure 6, the circuits through relays II and H are the same as those used in connection with the common battery telephone system and the magneto telephone system. The relays operate double contact switches as in the modifications described hereinbefore. One pair of contacts of the switches close the bell circuits. It is universal in automatic telephone systems that, when the number 0 is dialed, the operator is connected with the instrument. The dialing of number 0 involves ten impulses occasioned by the making and breaking of the circuit. In the automatic telephone modification of my invention, I employ solenoid 98, having an armature 91, a cam projection 98, a pivoted arm 84, carrying a contact point 83, which is normally held in contact with contact point 8| by spring 99. The arm 84 carries a foot 81 and the arm 94 carries a follower 95, as in the construction used with the magneto telephone system described above. Likewise, a gear wheel 92 is adapted to be actuated by spring motor 93 to drive a pinion 9|, which is keyed to shaft 98. A cam H8 is keyed to shaft to be driven therefrom. which cam is adapted to make and break the circuit ten times which it will be obvious is equivalent to dialing the operator. Provision is made for short circuiting the transmitter of my alarm system so that the dialing circuit will not have included therein the resistance thereof. For this purpose, I provide a bell crank lever I I6, pivoted at III to framework 85. In the position shown in Figure 6, in which both armatures 88 and 89 are in raised position, the bell crank lever I I8 is in position so that contact point 8 is separated from contact point 5. One arm of the bell crank lever H6 carries a toe 9 adapted to be suppoil'ted by lug I28, which is carried by the cam Referring now to Figure '7, if a fire breaks out in the vicinity of one of the thermostats so as to melt one pair of fusible links 8 and 9, as for example at I2I, the circuit through relays II and I4 will be broken. This permits the annatures 38 and 39 to drop as hereinbefore described. Four contacts will be made, namely, contact point 4| with contact point 43, contact point 44 with contact point 42, contact point 48 with contact point 50, and contact point 49 with contact point 5|. The contacting of points 4| and 43, and of points 48 and 50 will complete the circuits through the bells 54 and 59, as heretofore described, the batteries 53 and 51 furnishing the current for the ringing of the bells. when contact point 49 touches contact point 5| or when contact point 42 touches contact point 44, it being remembered that at this instant the position of the parts is that shown in Figure 6, with contact point 8| in contact with contact point 83, current will flow from the battery I through line I 0|. through the winding of electromagnet 98, through conductor 62 through microphone 65, through conductor 66, through bus bar 29, through line wire 30, through the district exchange, through the line wire 28, through bus bar 21, through conductor 61, through contact point 83, through contact point 8|, through line 82, through conductor 68, through contact point 44, through contact point 42, through conductor 63, through conductor 303, to the other side of battery I00. It will be seen that the current flow just described is that which takes place when contact point 42 contacts contact point 44. If contact point 49 contacts contact point the return circuit is as described except that the current will flow from conductor 82, through conductor 69, through contact point 5|, through contact point 49, through conductor 54, and then through conductor 303 to the other side of battery I00.

The current flow just described is suflicient to actuate electromagnet 98 to lift armature 91, enabling the cam 96, acting through follower 95 and arm 94, to pivot arm 84 around its pivot 86 to lift the toe 81 out of the notch 88, thus allowing the spring motor to rotate cam IIO. As soon as the cam turns through a small angle, the lug I20 will move from under toe II9, allowing the bell crank lever II6 to pivot around its pivot II1 through the force of gravity to make contact between contact points II 5 and 8. When this occurs, the line will be shunted when contacts 83 and 8| again touch, at which time current will flow from the battery at the central exchange through line 30, through bus bar 29, through conductor 66, through conductor I25, through contact point II5, through contact point II8, through conductor I02, through conductor 68, through conductor 82, through contact point 8|, through contact point 83, through line 304, through conductor 61, through bus bar 21, through line wire 28, to the central exchange, allowing the selecting devices to be operated by the breaking of the current as contact points 8| and 83 separate. It will be observed that the circuit is broken by the cam notches I28 the requisite number of times to dial the operator. When the notch 88 is again in alignment with toe 81, the spring 99 will cause it to drop into notch 88, thus stopping the cam IIO. Just before this occurs, however. cam surface I21, formed on toe II 9 of bell crank lever II6, will ride upon lug I20 so that it will again assume the position shown in Figure 6. The movement to this position, it will be observed, will separate contact points H5 and H8, thus breaking the short circuit of microphone 65, freeing the line for the transmission of the alarm signal to the operator, who plugs in in response to the call. On answering the call, the operator instantly will hear the ringing of the alarm bells being transmitted by microphone 65, and will proceed as before.

Referring now to Figure 8, I have shown the alarm system of my invention connected as a burglar alarm. It will be understood, of course, that the bell or gong I30 of the burglar alarm system will have a distinctive tone entirely different from either of the fire alarm signals. It will be understood, of course, that the relay I 3| is of the same type and similarly connected as relays II and I4, heretofore described. The relay I3I is provided with a transformer I 33 having a primary I 34 connected to the lines I and 2 of a source of potential which, as hereinbefore pointed out, may be the alternating house current. The

secondary I35 of the transformer I33 is connected in series with the winding of relay I3I by an external circuit in which is interposed one or a number of various burglar alarm wirings known to the art. For example, the window I36 may have a wire screen work shown diagrammatically at I31. Likewise, window I38 will have the tape wiring shown diagrammatically at I39, such that, if the window was broken, the circuit would be interrupted. The door I40 is provided with the known, hinged switch I4I such that, if the door be opened, the circuit is broken by the separation of contact points I42 and I43. The window I44 may have a window switch I45 such that, if the window be opened, the circuit is broken. These devices are well known to the art. Across the protective circuit I provide a shunt circuit comprising a pair of wires I50 and I5I, terminating in contacts I52 and I53. The circuit is adapted to be completed by a switch I54 which is operated by a cam I 55. The arrangement is such that cam I55 is adapted to be turned by a key. If it is desired to have the burglar alarm in operation, the position of the parts is such as shown in Figure 8. If the key be turned so that cam I55 raises switch I54 to complete the circuit through contact points I52 and I53, it will be obvious that the door or the windows may be opened without setting off the burglar alarms, inasmuch as the current now flows through the ,shunt circuit just described. As an additional feature, I provide a jack I60 such that contact points I8I and I62 are touching when the plug I63 is removed. When the plug is inserted, it will be seen that the switch I64 is placed in the circuit through conductors I65 and I66. The switch I64 is mounted on an extension cord in which conductors I65 and I66 are housed. The arrangement is such that, when the alarm is used in a residence, the plug I63 may be inserted in a wall socket at night, the extension cord allowing the switch I 64 to be placed under ones pillow. If one should hear an intruder who was successful in gaining entrance without setting off the burglar alarm, operation of the switch I64 would break the circuit through the switch member I61, thus turning in the burglar alarm. The alarm operates in the manner hereinbefore described in connection with the fire alarm systems. The armature I32 drops when the circuit through the winding of relay I3I is broken, connecting t e battery I68 across bell or gong I30 and connecting the transmitter across the lines 28 and 30, which go to the central exchange. The result is, as before, that the operator instantly hears the ringing of the burglar alarm gong' and informs the police department. If the police department is equipped with a police broadcasting station, a police scout car will obviously arrive at the scene of the entry within a short time.

Referring now to Figure 9, there is shown a perspective sectional view of a room equipped with a novel thermostat system. Along one wall of the room 204, near the top thereof, I secure switch members 200, the switches normally being in closed position. The switches are shown in greater detail in Figures 10 and 11. Spring actuated plungers, housed in cylinders 20i, tend to open the circuit. They are restrained from this action by wires 202 which have interposed at a plurality of places in their length fusible connections 203, which are shown in greater detail in Figures 10, 11, and 12. The other ends of the wires 202 are secured to the wall 204 of the room by springs 205 which serve to hold the wires taut. It will be observed that the wires may be of small diameter and that the fusible connections may be small so that the assembly is unobtrusive.

Referring now to Figure 10, mounted upon a suitable insulating base 2l0, housed within casing 200, I provide a conducting post 2 which carries a contact point 2|2. An inherently resilient post 2l3 carries a contact point 2. Another stationary post 2| 5 and another resilient post 2l6 are also mounted upon the base M0. The two switches thus formed are the equivalent of fusible links 8 and 9, heretofore described. Connected to the housing 200 are a pair of cylinders 20i in which are housed movable rods or plungers 2| 1. The rods 2" carry collars 2i! against which a spring 2|! is adapted to act, tending to move the rods to the left as viewed in the drawings. The stationary posts 2 and US are provided with openings 220, through which the end 22| of the rod 2ILis adapted to pass. Normally, the end of the rod 22l is held in retracted position with collar 222 against the bushing 223 by which the cylinder 20l is attached to the housing 200. In this position the contact points carried by the stationary and resilient posts respectively, are in contact so that the circuit is completed therethrough. The rods 2H are thus held in retracted position against the action of springs 2i9 by wires 202. Wires 202 are built up of a series of sections, each of which is suitably secured to a metallic strip 225 which can be best seen by reference to Figure 12. The terminal ends of the wire are connected respectively to rod 2|! and spring 202 as can be readily seen by reference to Figure 9. The metallic strips 225 are joined by soldering with a fusible alloy indicated at 226. If a fire should break out within the room, the fusible alloy will melt, allowing the pair of metallic strips 25 to separate. When this occurs, the spring 2l9 will move the rod 2l'l to the left as shown by the dotted lines in Figure 11. The end of the rod will pass through the opening 220 and contactthe fusible member, causing the contact points to separate, thus breaking the circuit. In use in my system, one loop of the circuit is completed through connecting a plurality of posts 2|5 and 2i i in series, while the other loop of thecircuit is completed by connecting a plurality of posts 2|6 and iii in series. It will be seen that, if any one of the wires breaks, that a trouble alarm will be turned in, while it requires the breaking or melting of one pair of wires to turn in a fire alarm. The elongated metallic conductor or wire 202 thus formed, makes a very sensitive thermostatic rod, inasmuch as the wires act as an antenna with respect to radiant heat and conduct the heat therealong, raising the temperature of the entire assembly so that any additional heat by convection directly over a point in flames will quickly cause a fusible alloy to melt, thus breaking the circuits through relays of my system, thus turning in a fire alarm.

It will be observed that I have accomplished the objects of my invention. I have provided an alarm system in combination with a telephone system such that a trouble alarm, a fire alarm, or a burglar alarm may be automatically transmitted over any of the existing known telephone systems without the necessity of disturbing the system with respect to telephonic communication. The assembly may be quickly and cheaply installed and makes fire and burglar alarm protection available to any subscriber to telephone service.

It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of my claims. It is further obvious that various changes may be made in details within the scope of my claims without departing from the spirit of my invention. It is, therefore, to be understood that my invention is not to be limited to the specific details shown and described.

Having thus described my invention, what I claim is:

1. In a telephone system having a central exchange, a pair of protective circuits extending through an area to be protected, a telephone transmitter, means actuated by the interruption of one of said protective circuits for giving an audible indication and for electrically connecting said transmitter with said central exchange and means actuated by the interruption of the other 'of said protective circuits for connecting said transmitter with said central exchange independently of said first connecting means and for giving a different audible indication.

2. In an automatic telephone system having a central station and subscribers stations, each of said subscribers stations having a dial which may be operated to call another subscriber's station or the central station, a protective circuit extending through an area to be protected, means independently of the subscribers station dial for dialing the central station, a microphone, an audible alarm signal in proximity to said microphone, and means actuated by the interruption of said protective circuit for operating said independent dialing means, for connecting said microphone with said central station and for operating said audible signal.

3. In an automatic telephone system having a central station and subscribers stations, each of said subscribers stations having a dial which may be operated to call another subscriber's station or the central station, a pair of protective circuits extending through an area to be protected, a microphone, an audible alarm signal in proximity to said microphone, a second audible alarm signal for giving a diflerent audible alarm in proximity to said microphone, dialing means independent of the subscriber's dial, and means actuated by the interruption of one of said protective circuits for actuating said independent dialing means, connecting said microphone with said central station and for operating one of said audible signals and means actuated by the interruption of the other of said protective circuits for operating said independent dialing means, for connecting said microphone with said central station, and for operating the other of said audible signals.

4. In a telephone system having a central station, a microphone, a protective circuit extending through an area to be protected, thermostatic means in said circuit adapted to open the same when a predetermined temperature is reached, window and door switches in said circuit for opening the same when a window or door is opened, said protective circuit containing a jack normally adapted to complete the circuit, an extension loop containing a switch normally completing an electric circuit therethrough, means for placing said extension loop in said jack whereby said protective circuit is broken through said jack and completed through said switch in said extension loop, means actuated by the interruption of said circuit for electrically connecting said microphone with said central exchange for giving an audible alarm signal adapted to be transmitted over said microphone, the arrangement being such that said protective circuit may be interrupted thermostatically due to fire, or manually in response to the opening of a window or door leading into the area protected, or manually by opening the switch in said extention loop.

JOHN M. JOHNSON.

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