US 2520340 A
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S. ROBINSON EMERGENCY ALARM SYSTEM Filed March 10, '1947 INVENTOR. 'rz .fa/7
Patented ug. 29, 1950 UNITED sTATEs PATENT,FF1CE EMERGENCY ALARM SYSTEM f 'i Sirman Robinson, 'ldfiacoxnm Wash. W Application Marchl', 1947, Serial lllo'l33g4'v1`1f?``1 i (-oiirc- 5) a 'oiaima This invention relates to safety apparatus and has special reference to1means to warn the proper authorities when conditions of danger exist.
The primaryobjectofmy invention relates to the early warning of fire conditions, especially in hotels and residences, factories, mills, warehouses and other structures, wherein a telephone system, or its equivalent, is installed. It also has reference to means of Warning against other abnormal conditions, such as pressureland water level in boilers, temperature in carrying out various `processes, in cold storage plants, and in anylsituation Where the breaking or making of an electric circuit may be utilized to `warn those in control of the apparatus that conditonsare, or are approaching, the abnormal.
I attain these objectsby the devices, mechanisms and electric connectons illustrated in `the accompanying drawings, in which- Fig. 1 is a schematic or diagrammatic illustratration of my invention as applied to a fire alarm controlled by the heat of a room in a hotel; and Fig. 2 is an illustration of a partiof the same system when such an alarm is Controlled by smoke `in the hotel corrldor ventilator.`
Similar numerals of reference refer to similar parts throughout the severalviews. It is a familiar fact that, 'if a fire in a hotel,` or other structure, can be detected and reached promptly, before it has attained an explosive or raging stage, it` may be totally extinguished with comparative ease. This fact makes it of Supreme importance that theproper persons should beimmediately informed not only that a fire danger exists, but also, that they be informed of its exact location and, if the fire occurs in an occupied room, that the occupant be notlfied, Also, to prevent panie, it is important that no general alarm be sounded unless a general confiagration imminent. o o 'I'o accomplish this purpose I interconnect the particular room telephone-` circuit electrically with the apparatus which is Sensitive to the abnormal condition of heat in the room, in such manner that, under normal conditions, there is no possible interferencewith the operationoi` isthus affectedl'and,,Simultaneously causing the special audible bua'rer`` to sound. And, ``if the alarm 'occurs `when the switchboard is `unattended, as at nghtaloudwalarm 'is rungin the night ``clerlr's roomfor,elsewhere4 Thus the room occupantis -notified of his Udariger and possibly may be able to extingush the :blaze himself,'=and theihotel :personnel is notified of `'the particular room Where the'fire is located 'and can: send help to that-room without'disturbing the other guests. If, however,` thefire is not located in a` room but in a closet locatedinrone of` the corridors,` then thermostats may be placed, in multiple, in ,z the severalclosets, and'asmoke detecting electric eye maybe placed in 'the ventilator at its connection with thefipartiolular corridor; alsoin multiple with saidithermostats', and said circuit connected witha special annunciator light in the P. B. X .and/or switch board, for that particular fiOOI'; `1 i These above described `Sensitive apparati are mounted`` in the direct current, low voltage, cirouit of the telephone (P. B. X) 'private branch exchange. i i i i Before dcscribingltheiparticulars of theinterconnections a brief` Outline maybe given of `some ofthe various `'fields which'` may utilize this system/to warn theuproper persons of an abnormal condition irrthe'` field for which they are responsible. The electric time clockmay get out of order, or the current' supplying it may he cut off, then the oifice of the factory would automatically be notified and could takewsteps to remedy the defect. The temperature: ofa''subs'tation` or unl occupied building :might riseitoz aidanger point,
and this factzwoul'd immediately be calledito the attention of :the proper persons; The electric current Operating a refrigerator plant,` cold locker plant, or other structure :might be cut off, in which case the plant'operator would be immediately informl` and:` could take proper precautions. The high or low temperature at which a certain processing mustbefcarried' on can be mzaintained` at that temperature by the' men in charge (being notified when the*` normalrange ieeitceeded` In boiler operation such a signal? may be applied to the pressure gauge to notify the engineer'when such conditions i e'xceed the' prescribe'd `liinits. These applications'of-my alarm system are given only as a brief indication of the very many uses to which it maybe put,reither in connection with a telephone systemoriwithout :the full telephone switch board. i i 'i i i f i The private branch exchange (P.` ZB'. X) is` normally equipp'ed* with a low'voltage direct current circuit over which the talking current passes, and an alternating current circuit utilized for ringing the selected telephone bells. It also has switches, or keys, which connect either of the said electric circuits to the individual branch plug.
Referring, now, to the drawings it will be seen that a thermostat is suitably located in the room 6 of the hotel. This thermostat 5 is normally open and is' adapted to close upon the heat of the room becoming abnormally high. The Wire 'I leads from the negative side of the direct current source, the battery 8, to the thermostat 5. The other side of the thermostat 5 is connected by the Wire 9 to the jack IO of that particular room on the private branch exchange board and/ or switch board of the hotel telephone oflice.
This jack IO comprises the usual two prongs Il and l2 adapted to be contacted by the plug |3 in the usual manner. The prongs and |2 are connected directly to the telephone |4 in the room 6 by the wires T and R respectively. A third prong l5 is mounted between the said prongs and |2 and is normally in electrical contact, either directly or through an intermediate prong |6, with the prong |2. The above mentioned Wire 9 is connected to the said prong |5. The contact between the prongs |5 and 16 (or |2) is broken When the 'plug |3 is inserted in the jack IO, thus dissociating the telephone circuits from my alarm system when the telephone is in use.
A test key IT is also located in the room 6 and is adapted to short circuit the thermostat 5 When the key is operated, thus closing the thermostat circuit. The purpose of this test key is, when a new tenant is shown his room, the bell-boy Will call his attention to the fire alarm and Will operate the test key, thus setting off thev alarm by ringing the bell of the telephone M and also energizing the special light and buzzer in the oflice P. B. X to show that the alarm circuit is in good order. When the key |1 is turned off the circuit returns tofnormal. 'Such a demonstration to the tenant at once gives him confidence in the fact that every precaution is being taken to assure him of Safety from fire and educates the public to be fire conscious and in that Way reduce the fire hazard to human life in hotels, apartments and other structures.
The prong E5 of the jack ill'is connected by a wire IB to the special relay |9, and the Wire 23 leads therefrom back to the positive side of the battery 8. Thus when the thermostat 5 closes the circuit the current flows by the wires 7, 9, I 5, |6, IB, the relay magnet I 9, and the Wire 29. This energizes the magnet |9. The armature 2| of the magnet |9 carries two contact points 22 and 23 which are respectively connected by the wires 24 and 25 to the wires of the alternating circuit 26. These points 22 `and 23 are respectively adapted to contact with the points 21 and 28 When the relay magnet is energized. II`he point 21 is connected to the wire T by the Wire 29, and the point '28 is connected to the Wire R by the Wire 30. Thus as long as the thermostat 5 holds the room circuit closed, the alternating current will ring the bell of the telephone |4 in the room 6.
- A night alarm bell 3| is located in any desired place, as the night clerk's desk, and is connected by the wires 32 and 33 to the respective points 22 and 28, and a cut-off switch 34 is located in this branch circuit, said switch beingnormally open when the P. B. X is manned but is closed when the P. B. X is not attended, therefore said alarm bell 3| will sound when the thermostat 5 closes the relay switch |9 if the switch 34 is closed. A special light (red) 35 is mounted in the P. B. X board adjacent the white calling light of the board for the particular room 6. This light 35 and the special buzzer 36 are connected in the direct current circuit between the wires |8 and 23 by the wires 37 and 38; thus When the thermostat 5 closes the circuit the said signals will indicate the particular room in which the fire is located.
As shown in Fig. 2, which illustrates the alarm as applied to the corridors of the hotel, the alternating current in the circuit 26 energizes the generating lamp 39 whose rays shine across the ventilator 40 on the grid 4| which is connected to the relay 42, holding the switch connection 43 open. When smoke of suiiicient density interferes with the screen 4| receiving its full light, the switch 43 closes the above described circuit '1, 9 and energizes a special alarm circuit, as above described, on the P. B. X board and/or switch board, for that particular fioor. Thermostats 5 may be inserted inparallel at various points, as closets and stairways, in the said corridor circuit.
In this case, there being no telephone in the corridor, the wires T and R and their connections 29 and 30 are eliminated. Also in this case the armature 2| only makes and breaks the connection between the contact Epoints 23 and 28,
. and the special signal light 35 and buzzer 36 will indicate the particular floor at which the trouble exists.
So, to summarize, it will be seen that as soon as the room temperature reaches the danger point selected for the thermostat, the thermostat closes the direct current circuit 1, 8, 9, |5, |6, |8, 19, 20 and energizes the relay |9, thus causing the contacts 22, 21; 23, 28 to close the alternating circuit 24, 23, 28, 30, R. T. 21, 22, 25 and to ring the telephone bell in the room 6. Waking the tenant, who immediately lifts the phone iii thus breaking the ringng circuit of the telephone and indicating on the P. B. X that the phone is lifted. If he hears no voice on the phone he replaces it and the bell again rings. Meantime the light 35 and the buzzer 36 continue to notify the operator of the danger and she inserts the plug |3 in the jack IO, thus breaking the alarm circuit and she may talk to the room tenant notifying him of the emergency (if he has not already discovered it). Meantirne the alarm circuit may also notify the proper fire ofiicials so that the fire may be quickly extinguished before it has reached dangerous proper--l tions, and Without unnecessary alarm to the other tenants of the hotel.
Similarly it is evident that other means for making or breaking the circuit 'l--9 than the thermostat 5 or the electric eye 43, may be used for energizing the alarm circuit, such means depending on the type of control desired, such as pressure, temperature, density, weight, time, or fiow of electricity. In each case the particular instrumentality, being Sensitive to the abnormal conditions present, immediately and automatically sends a Warning to the control station and to the operator in control of theA apparatus.
It is, of course, understood that changes in the details of my invention may be made withoutdeparting from the spirit thereof as outlined in the appended claims.
Having described my invention, What I claim and desire to secure by Letters Patent, is:
l. An automatic emergency alarm comprising, in combination, an open electrified direct current metallic circuit; an apparatus, Sensitive to abnormal conditions and mounted in said direct current circuit and adapted to close said direct current circuit upon conditions becorning abnormal; an open alternating current metallic circuit; an electric operated alarm; and a relay switch in said direct current circuit and adapted to close the connection between said electric operated alarm and said alternating current circuit when said direct current circuit is thus energized, and to close said alternating current cirn cuit through said alarm, Whereby said alarm is operated when such abnormal condition exists.
2. An automatic emergency alarm comprising, in combination, an open electrified direct current metallic circuit; an apparatus, sensitive to abnormal conditions and mounted in said direct current circuit and adapted to close said direct current circuit upon conditions becoming abnormal; an open alternating current metallic circuit: an electric operated alarm in said open alternating current circuit: and a relay switch in said direct current circuit and adapted to close said alternating current circuit upon the closing of direct current circuit. Wherebv said alarm is operated when such abnormal condition exists.
3. An emergency alarm comprising, in combination, an apparatus Sensitive to abnormal conditions; an open metallic electric circuit adapted to be closed by said Sensitive apparatus upon the conditions becoming abnormal; an electric telephone metallic circuit including a normal plug and jack, said jack having two resilient prongs connected resuectively to the ringing and talking sides of said telephone circuit; a third prong mounted in said jack and normally in electrical contact with said ringing prong, said third prong being connected in said first electric circuit, whereby when said first circuit is closed, said ringing side is energized and whereby, when said plug is inserted in the jack said first circuit is opened.
4. An emergency alarm comprising, in combination, an apparatus sensitive to abnormal conditions; an open metallic electric circuit adapted to be closed by said Sensitive apparatus upon the conditions becoming abnormal; a relay,
with circuitbreaker magnet therein, connected in said first circuit; a second open metallic electric circuit, adapted to be closed by said relay magnet upon the closing of said first circuit; an electric alarm apparatus in constant connection, on one side, with one side of said second circuit between its source and said relay and, on the other side, in connection with the open side of said relay, whereby When said relay magnet is energized by the closing of said first circuit said` alarm apparatus is energized.
5. An automatic emergency alarm comprising, in combination an open electrified direct current metallic circuit; an apparatus Sensitive to abnormal conditions, mounted in said direct current circuit, and adapted to close said direct current circuit upon conditions becorning abnormal; an open alternating current metallic circuit; an electric operated alarm, including a normal telephone circuit; and a relay switch in said direct current circuit and adapted to close the connection between said telephone circuit and said alternating current circuit, whereby said alarm is operated when such abnormal condition exists.
6. An automatic emergency alarm as set forth in claim 5, together with a manually operated switch in said direct current circuit and adapted to short-circuit said Sensitive apparatus, whereby said alarm circuit may be tested.
7. In an automatic emergency alarm, 'the combination of a normal telephone system, having telephones in its customers stations and a P. B. X board controlling said telephone stati'ons; apparati Sensitive to abnormal conditions at each telephone station; an open metallic electric direct current circuit to each said station and adapted to be closed by said appara-tus therein upon the conditions becoming abnormal, and normally in electrical contact with the ringing side of said telephone circuit in said station; means adapted to disconnect the connection between said ringing side of said telephone circuit and said open direct current circuit when said telephone circuit is in normal use; a relay magnet mounted in said open direct current circuit; and an open alternating current circuit adapted to be closed upon the energizing of said relay magnet, and having its open side connected to the telephone circuit to the station, whereby said telephone at said station is rung When such abnormal condition exists.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 302,935 Philips et al Aug. 5, 1884 647,588 Thompson Apr.. 17, 1900 986,355 Bruhn Mar. '7, 1911 2,080,136 Johnson May 11, 1937 2,121,282 Bradford June 21, 1938