US2022991A

US2022991A - Alarm transmitting system

Info

Publication number: US2022991A
Application number: US700544A
Authority: US
Inventors: Orville L Walter
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1933-12-01
Filing date: 1933-12-01
Publication date: 1935-12-03
Anticipated expiration: 1952-12-03

Description

Dec. 3, 19351 o. i.. WALTER ALARM` TRANSMITTING SYSTEM Filed Deo. l, 1935 2 Sheets-Sheet J.

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O. L. WALTER l ALARM TRANSMITTING SYSTEM 2 sheets-sheet v2 Filed Deo. l, 1953 ADV sxmwlllm/M IPRII w /lIl /NVENTOR 0 L. WALTER A7' TORNEV This invention relates to an alarmitrans'mittin l. system and more particularly-.to,sucharsystem whereby the alarm is transmittedbyradio. f fr of the larger cities, which maintain at police cars equipped witlrradio;receivers.l Upon.k receipt of an alarm at the central alarmfoflice (usually transmitted thereto,rbyftelephone) in wzf y he: radio `transf the .partlculawaa :assigned to structions arelb mitter directing.,l

oa'dcast over the neighborhood'from-which thealarmhasbeen f received, to proceed :to the` ypremises :in questions):

While this service has provedio be-very emcient have departed. 'I'hisdlay `of progress of the robbery, theyfcould in manylcases have been captured. 4 l y It is accordingly an; ojtfne, 'invention tof inventionis'there'dutioni a switch on the protected transmitted by radio.

According to another feature of 3 practically all the equipment used,

tion and maintenance expenses. ,e ,e In accordance with a preferred embodiment of 4 the invention, a plurality of reproducing*` units,

tral alarm bureau. One unit is assigned to each protected location, the record of each unit having inscribed thereon the address of the associated location as well as any other appropriate alarm message. The units are preferably continuously in'operating condition and apparatus, such as a relay circuit, controlled by switches on the protected premises, are effective when operated to maANsmrrlNo srs'ran j "rauaa in the apprehension pfcr mnalsrit hasfbeen 0by served that in' manylcasesof a-robbery, no ,oppor-3l tunity is aiorded thoseon thevpremisesto put in. a call to the centrallfbureau untiLthe :intruders `i181?.-.l'fsultszin aff failure to apprehend the1criminalswhereas,ify the,` v alarm could have been. broadcasaduring.actual..

protective". apparatus required-1A are provided whereby upon themere actuation of premiseszan alarm message including the address of the. premises, isv

, such as tele'graphones, are provided at the ,cen-

sary atthe premises to 'causev transmissionof the There have recently beenuestablishedfincertain police radidcar ,departmentsKV f various locations inf'thef city#v :complete alarm by" the radio `trans'n'litter at the rcentralf bureaufis the actuationl of a switchand,` v :as ftheseI` switches may be concealed. about the :premises or may'evenbecarried on the person zof 'an''em'pl'oy'ea fasf disclosed for 'example in De Munbrienratenlt 824,663 of september 22, 1931, ithel'eiciency'of the 'i'presenty ype of pol e radio 10 Vcarservi'ce.may b greatly increased. -'A complete understanding `ofl theinventionv and an appreci'ationflf'its"various `feajvtures',may be L: u'gained from a consideration of thefollowin'gi detailed description and're'ferenceto the annexed15 'drawingsliniwhicht VFig.' 1 sli'ows an alarm f' ,ansmitti'ng system,r the :reproducing unintvs'off which T are normally `inoperatingcbnditomand .Y N Fig, 12 show-sa modification ofthe system of Fig.` 20 1 in accordance `withl ywhichthe reprodurclingunits j arevn'ormallyvv inoperative.

il 'Referring now toiFigl. 1, the apparatusshown to -`.the s right Vof line X"-'X "-is' preferably located at the centralala'rm ofiice, and thelalarm switches 25 t0 the left of line X-X are locatedat three aseparatedareasf tolbfprotected. 1 jIt should beunderstood fof course that although in orderto illusthe: 111ivemion` .asV Simplv and clearly `as possible, :only `one switch at each `v area has' `been shown and only three `areas have beenfinclu'ded in Athe' system, a *pluralityv of trate the principles of y y l switches may be -providedon the protected premthe invention, ,y in. 4tleysiern except of course, the actuating switchesyisl located at the central bureau thus reducing installaisesI in-'ar'zcordanoe with `theusual practice 'and a large numberf of lareas'may be served by the one 35 fAsshown, r'the switch at each` protected area is connected by'a line to thecentralalarmoiiice. Here a plurality of telegraphone reproducing units are provided, one'unitbeing associated with each 40 line. The units are maintained in operating condition by motor 1. A relay isassociated `with each line and, when operated, connects the output of an associated telegraphone unit to the input of radio transmitter I2. This transmitter is preferably tuned constantly to a particular frequency, the radio receivers of the police cars being tuned to this same frequency. Any message sent out by transmitter I 2 is therefore picked up by the radio receivers ofv the police cars. A microphone 40 is provided through which the announcer at the central` oil'ice may transmit information and orders to the drivers ofv thecars. The .microphone is connected to the' radio transmitter-,throughcontactsof relay 63 which. upon connection of a telegraphone unit to the radio transmitter, operates and disconnects the microphone from the radio transmitter thereby assuring priority to the alarm message of .the vconnected telegraphone unit. It is not considered necessary to describe in detail the manner in which the microphone output is associated with the input circuits of the radio transmitter as arrangements of the kind are well known and disclosed in the art. Helsing Patent 1,442,146, for example, discloses a radio transmitter circuit in accordance with which a microphone (I1) is associated with the modulator circuit through a transformer (I8). A monitoring loudspeaker I3 is associated with the transmitter and reproduces, for the information of those at the central office, the information being broadcast. A lamp is associated with each reproducer unit for Indicating that a particular unit has been connected tothe transmitter. A priority control switching arrangement indicated at 62, is preferably included whereby, should a second alarm be received while the alarm message of a prior unit is being-broadcast, interference with the message by the connection of the second unit to the radio transmitter is prevented. Upon interruption of the first alarm, however, the message of the second unitis immediately broadcast. Priority or lockout arrangements are well known in the telephone, radio and public addressv system art and it is not believed necessary, therefore, to describe the operation of priority control 62 in detail. By way oi example, however, reference is made to I-Iulsh Patent 1,118,490 as a disclosure of a priority control arrangement designed for' telephone system use which might well be applied to the present system. It will be understood, of course, that

units

4I, 42, and 43 would replace subscribers stations I, 2, 3, and 4 of the Hulsh patent, the outputs of the units being completed through relay contacts as shown by Huliish and the operation of relays 8-28 of the Hulflsh patent being controlled by the completion of the respective alarm circuits over lines L1, La and La.

` Let us assume now, for purposes of description, that a robbery is taking place at protected area No. 1 and that some person at that location operates switch I in order to transmit an alarm. Operation of switch I completes a circuit from battery 20, winding of relay 8, line L1, make contact of key I to ground 4, relay 8 operating over this circuit. Relay 8 by operating (1) completes a holding circuit for itself traced from battery 20, winding of relay 8, switch I1, inner right make contact of relay 8 to ground 35, the relay being held in operated condition over this circuit even though switch I is restored to normal position, (2) completes a circuit through its second right make contact by which the output of reproducer 4I is connected to radio transmitter I2, (3) completes a circuit traced from battery 30, left make contact of relay 8, lamp 26 to ground 33, lamp 26 being energized over this circuit and indicating that the associated reproducing unit 4I has been connected to the radio transmitter and (4) completes a circuit traced from battery 61 winding of relay 63, outer right make contact of relay 8 to ground 64, relay 63 operating over this circuit to disconnect microphone 40 from radio transmitter I2, thus affording priority to the alarm message of unit 4I. As reproducer 4I is continuously operated by motor 1 and as its output has now been 'connected through conductor 46 and

conductors

41 and 45 to the linput of radio transmitter I2,

the message recorded 'on record 23 is broadcast by the transmitter. 'Ihis message includes the address of protected area No. 1 and any other appropriate alarm message. The broadcast alarm is picked up by the radio receivers of the police cars and the car assigned to the district including protected area No. 1. proceeds to that address. The attendants at the central alarm oflice are enabled to hear the alarm being transmitted through monitoring loudspeaker I3. 10

By virtue of the holding circuit traced above, relay 8 is held in operated condition thus causing the alarm to be repeated. After the alarm has been repeated several times, an attendant at the central olce may momentarily move switch l5 I1 to break position thus interrupting the holding circuit of relay 8 which thereupon restores to normal land interrupts the path over which the output of reproducer 4I was connected to the input of the radio transmitter. The energizing circuits of lamp 26 and relay 63 are also interrupted as relay,8 restores to normal. Switch I1 after being momentarily moved to break position is allowed to restore to its normal make position in order that the holding circuit of relay 8 may 25 be reestabllshed should the relay be again operated.

After disconnection of the reproducer unit from the radio transmitter and reconnection of microphone thereto (upon restoration of relay 63 to 30 normal position), the microphone may be utilized by the attendants in broadcasting further instructions to the police cars.

It has been assumed above that no prior unit was connected to the input of the radio trans- 35.-

mitter at the time reproducer unit 4I was connected thereto. Had the alarm of a prior unit been broadcasting, however, priority control switching arrangement 82 referred to above would have prevented interference therewith by the con- 4o nection of unit 4I. Lamp 26 would have been lighted in the usual manner, however, thus indicating to the attendants at the alarm oilice that an alarm had come in from area No. 1 and was being held for transmission. As soon as Ieasible they would then interrupt the operation of the prior unit whereupon the message of unit No.

4I would be transmitted.

Operation of switch 2 at protected area No. 2 or of switch 3 at protected area No. 3 results in 50 the connection of the associated

reproducer unit

42 and 43 respectively, to the radio transmitter and -in the lighting of the associated indicator lamp, 21 and 28 respectively, in a manner similar to that described in detail above in connection with the operation of switch I.

Referring now to the modification of the invention shown in Fig. 2, the system illustrated is in general similar to that shown in Fig. 1 and decontrol switching apparatus 62. 70.--

Assuming now, as before, that switch I is actuated, a circuit is completed from battery 28, winding of relay 8, line L1, make contact of switch I to ground 4, relay 8 operating over this circuit. As previously described, relay 8 by its operation com- 75- pletes: (l) a holding circuit which holds the relay in operated condition, (2) a circuit to energize lamp 26 and (3) a circuit to operate relay 63 and, in addition to these circuits previously described, completes a circuit through the left outer make contact of relay 8, to supply current to motor H which is thereby set into operation. Motor llu operates reproducer Il and as the output of the reproducer is connected to the radio transmitter, the message recorded on record 23 is now broadcast by the transmitter.

As previously described, operation of switch 'l1 to break position causes interruption of the broadcast and restoration of the apparatus to normal.

Priority control switching apparatus 62 func-r tions as previously described to prevent interference with a message being broadcast should a second reproducing unit be set into operation.

Although specific embodiments of the invention have been selected for detailed description it is not intended to indicate that the invention is so limited. For example, the recorded message need not be an alarm message but may be any predetermined announcement. It is, as a matterof fact, intended to indicate the scope ofthe invention only by the annexed claims.

What is claimed is:

l. In anA alarm system, a central olce, a plurality of protected locations remote from the central ofllce, lines connecting the central oflice and the protected locations, a radio transmitter at the central oiiice, a microphone normally connected to the transmitter for transmission of l'ocal announcements, a plurality of reproducers at the central office, said reproducers being normally in operating condition, a record associated with each of the reproducers having recorded thereon the address of one of the protected locations, means at each protected location which, when operated, causes the output of the particular reproducer with which is associated the record bearing the address of that location at which said means is operated to be connected to the radio transmitter and additional means for disconnecting the microphone from the radio transmitter when one of the reproducers is connected thereto.

2. In an alarm system, a central oiiice, a plurality of protected locations remote from the cen- 5 tral cnice, lines connecting the central oiiice and the protected locations, a radio transmitter at the central office, a microphone normally connected to the transmitter for transmission of vlocal announcements, a plurality of reproducers at the central office, said reproducers being normally inoperative, a record associated with each of the reproducersV having recorded thereon the address of one of the protected locations, means at each protected location which, when operated,

causes the particular reproducer with which is associated the record bearing the address of that location at'vvhich said means is operated to be set into operation and its output to be connected to the radid transmitter and additional means for ldisconnecting the microphone from the radio transmitter when one of the reproducers is set into operation. and connected thereto.

3. In an announcing system, a central announcing cnice, a plurality of control locations remote from the central office, lines connecting the central office and the control locations, a radio transmitter at the central office, a microphone nor- ;mally connected'to the transmitter for transmission of local announcements, a plurality of reproducers at the central office, a record associated with each of the reproducers, each record having recorded thereon a message more pertinent with respect to one of the control locations than to any of the other control locations, means at each control location which, when operated, causes the output of the particular reproducer with which is associated the record bearing the message pertinent with respect to that location at which said means is operated to be connected to the radio transmitter and additional means for disconnecting the microphone from the radio transmitter when one of the reproducers is connected thereto.

ORVILLE L. WALTER.