United States Patent 3713125

An automatic digital-encoding burglary-robbery apprehension system is described which utilizes existing telephone lines and direct radio transmission links from an area control center to a patrol car or helicopter. The transmitted alarm signal is digitally coded to provide location identification.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
348/E7.049, 455/18
International Classes:
G08B25/08; G08B27/00; H04N7/10; (IPC1-7): G08B19/00
Field of Search:
340/224P 343
View Patent Images:
US Patent References:
3467889ELECTRICAL MEASURING SYSTEMS1969-09-16Brough-Cunningham et al.
3417332Frequency shift keying apparatus1968-12-17Webb
3305635Multitone data transmission system with data bits comprised of combinations of data tones and rest tones1967-02-21Kadis
3290597Emergency assistance radio signaling system1966-12-06Denny et al.
3289152Acoustic signaling system1966-11-29McIlwraith et al.
3271588Digital keyer for converting d. c. binary signals into two different output audio frequencies1966-09-06Minc
3233243Decoder and printer1966-02-01Cooper et al.
3230454Radio alarm system having preselected code sequences1966-01-18VanBurkleo
3149317Radio alarm1964-09-15Brugliera et al.
2979706Radio warning system1961-04-11Simon et al.

Primary Examiner:
Pitts, Harold I.
Parent Case Data:


This application is streamlined continuation of Ser. No. 794,873, filed Jan. 29, 1969, now abandoned.
What is claimed as new in support of Letters Patent is

1. An alarm system comprising:

2. An alarm system as defined in claim 1 including:

3. An alarm system as defined in claim 1 wherein said means for displaying said digital code includes:

4. An alarm system as defined in claim 1, including:

5. An alarm system as defined in claim 1, including:

6. An alarm system as defined in claim 4, including:

7. An alarm system as defined in claim 1 wherein said telephone transmission line comprises a community antenna television coaxial line.


Many remote-indicating alarm devices have been employed heretofore in law-enforcement communications systems. In general, these devices provide an alarm signal at a central office in response to the activation of an alarm switch or intrusion detector at the premises under surveillance. In response to the alarm signal an operator contacts the police station by telephone, at which time radio communication with law-enforcement offices in a patrol vehicle in the vicinity of the surveyed premises is established in order to affect apprehension of the robber or intruder. The apprehension process cannot start until the police communications control center has processed the alarm call and has located and dispatched an available vehicle to the scene of the crime. It has been found that this process consumes an average of 7 to 12 minutes, during which time 80 percent of the criminals make their escape.


The present invention relates to an automatic system which significantly reduces the response time between the detection of a crime or an incipient crime and the deployment of the police to the scene of the crime. In accordance with a first embodiment of the invention, a coded signal which identifies the location under surveillance may be automatically transmitted by radio, or by a combination of a wire-radio link, directly to patrol vehicles or helicopters in the general area of the surveyed location. The radio signal received at the patrol vehicle or helicopter is decoded to present numerical and printed data identifying the location of the tripped alarm, thereby permitting the patrol vehicle to proceed directly to the scene of the crime. Thus, the delays now experienced in existing law-enforcement communications systems are obviated.

As will be described in a subsequent part of this specification, the invention may be constructed in a number of embodiments, certain of which include burglary, robbery, fire and other types of emergency sensors which operate in conjunction with address encoding and data transmission equipment to automatically relay an alarm to specified locations where the data are decoded, displayed and printed out, and if desired, presented as a recorded voice message. Other modifications of the invention will also be described hereinafter.

It is therefore an object of the invention to provide a novel and improved alarm system utilizing a coded source identification which is transmitted via a radio link.

Another object of the invention is to provide a novel and improved radio communications system including a mobile radio receiver having demodulating and decoding means therein for displaying and printing the address of an activated remote alarm.

These and other objects of the invention will be more readily understood by making reference to the description which follows and to the related drawings.


FIG. 1 is a block diagram of a first embodiment of the invention.

FIG. 2 is a detailed schematic diagram of the location encoder portion of the system of FIG. 1, utilizing a digital coding technique.

FIG. 3 is a schematic diagram of the decoder and display portion of the system of FIG. 1.

FIG. 4 is a block diagram of a second embodiment of the invention wherein an intermediate telephone link is employed.


Referring to FIG. 1 there is shown a block diagram of a first embodiment of the invention, and which comprises a plurality of input signal devices. These may include a hidden switch 1 of the type which may be secretly closed by the intended victim of a robbery. Such a switch may be any of the suitable and well-known types employed in tellers or cashiers cages, under the counter in stores, or similar installations well-known to those versed in the art. For the protection of unattended premises, a burglary intrusion sensor 2 may be used to generate the input alarm signal to the system. These detection devices may comprise proximity switches, trip wires, photoelectric surveillance devices, foil continuity-sensing circuits and the like commonly employed in burglar alarm systems. Additionally, an individual who is to be protected against robbery, such as a cashier, may carry a remote control device 3 on their person which is capable of initiating an electrical or ultrasonic signal upon command. Alternatively, a fire sensor 4 and/or other type of emergency detection device such as manual emergency switch 5 may serve as the input to the system. Such devices are well-known in the art. The particular construction of the alarm sensor or alarm initiating switch is merely incidental to the invention, as will appear.

The initiation of an alarm signal from switch 1, detection device 2, remote control device 3, fire sensor 4, or switch 5 will supply a signal on line 6 to the location encoding device 7. The address or location of the protected person or place is encoded, typically as a six digit number (as will be described in detail later) and transmitted on line 8 to radio transmitter 9. That is, the location or address of the premises is stored in the encoding device 7 and is transmitted by transmitter 9 whenever the system is activated by a signal on line 6. Details of the encoding device 7 will be given in a subsequent portion of this specification.

Radio transmitter 9 automatically broadcasts the location code appearing on line 8 for an interval sufficient to permit reception and recording at a mobile receiving unit. In a preferred construction, transmitter 9 employs frequency shift modulation for the transmission of the address code. The transmitted code is picked up by radio receiver 11 which is preferably located in a mobile vehicle, such as a patrol car or helicopter patrolling the general area in which the protected premises are located. The radio link between transmitter 9 and receiver 11 is indicated at 12. The receiver output on line 13 is demodulated and decoded by a suitable demodulatory decoding device 14, the construction of which will be described hereinafter. The decoded output on line 15 is displayed in arabic numerals on display device 16 and/or printed out on printer 17.

Any suitable line code may be employed in the data channel (15) between decoding device 14 and output device 16 or 17. Also, an audible signalling device, such as buzzer 18, may be energized via line 19 whenever a signal is being picked up by receiver 11. This will alert the personnel in the patrol vehicle to an incoming address signal which should be investigated.

If desired, the system may be extended to include an additional radio receiver 21, located at the police station 22. This receiver 21 is responsive to the digital code transmitted by radio link 23 from transmitter 9 in addition to radio transmitting equipment (11) in the patrol vehicle. The received digital location code is demodulated, decoded and displayed by means of display device 24 and/or printed by printer 25. This will permit simultaneous reception at the patrol vehicle and the station 22 for over-ride monitoring control.

A tape recorded verbal message may be contained in device 26 and transmitted in lieu of the digital location code from device 7. That is, in response to one or more of the sensor devices 1-5, the location of the actuated sensor may be verbally played back from a recorded tape in the tape playback device 26. This message is transmitted via radio transmitter 9 to receiver 11 where it is reproduced via speaker 27.

Receiver 21 is also provided with a speaker 28 to reproduce the received recorded location message from device 26 and transmitter 9.

When activated by an intruder, intrusion noises may be picked up at the site of the protected premises by microphone pick up 29 and broadcast in the same manner as the above-described recorded message, for ultimate reproduction through speaker 27 and/or 28.

Fires are immediately detected by fire sensor 4 and an alarm signal is via the location encoding device 7 and transmitted directly to the nearest fire station 31 by radio link 32. Digital receiver 33 decodes and reads out the site location of the fire by means of display device 34 and/or printer 35.

The site or location code may be generated by an automatic telephone dialer 36, a telephone card dialer 37, or a touch-tone telephone 38, in addition to (or in lieu of) the previously described location encoding device 7. As in the first-described case, the code is generated in response to one of the emergency sensors 1-5. The received telephone-type code is decoded to indicate the origin of the activated emergency sensor 1-5.

The emergency sensors, in addition to those specifically enumerated above, may comprise suitable and well-known manually operated switches for use in medical or other types of emergencies. In this regard, an ultrasonic or radio remote control transmitter may be used to initiate the emergency signal.

Referring to FIG. 2 there is shown a schematic diagram of a device suitable for encoding the address location. The multiplexer shown in FIG. 2 corresponds to the block identified as "location encoding device 7" in FIG. 1. The apparatus shown will generate a six-digit number in response to closure of the sensor switch 1. This will close a path to ground 41 and trip flip-flop 45. This action will send a pulse on line 43 to the binary to octal converter 44. Counting or timing pulses from oscillator 49 will be registered in the serially connected flip-flops 48, 47, 46 and 45. As each flip-flop is tripped, it will send a pulse to the converter 44, which in turn supplies an output to appropriate ones of gates 51-56. These gates in turn provide outputs to multiplexing gates, a typical set of which are identified as 57-60. The sequential outputs from these gates is supplied to multiple-frequency oscillator 62, the tone-coded output of which appears on line 63 for transmission to the radio transmitter or transmission channel.

Typically, the first digit of the six-digit number identifies the geographic sector; the second digit describes the type of service required, and the remaining four digits describe the specific location of the activated sensor.

In addition to the digital encoding technique described in connection with FIG. 2, other well-known tone-encoding techniques may be utilized.

The tone modulated signal from radio transmitter 9 is received by radio receiver 11 located in the patrol vehicle. The received signal is detected, demodulated and supplied as a decoder which converts it to a parallel line code. The output of the decoder 14, appearing on line 13 directly drives a display device such as a numerical readout tube where it may be seen by the operator. As will be apparent to those versed in the art, a plurality of readout tubes will be employed in cascade, depending upon the required number of decimal places needed to display the transmitter site or address identification which directs the patrol officer to the site of the activated intrusion detection device.

If desired, the radio receiver 11 may be equipped to provide a printed output of the transmitted site address in addition to the visual numerical display. Other modifications within the scope of the claimed invention will appear to those skilled in the art.

Referring to FIG. 4, there is shown a second embodiment of the invention, whereby burglary, robbery, emergency and fire sensors, microphone pick up of intrusion noises, pre-recorded emergency tape messages, telephone automatic dialing, touch-tone and card dialer devices are automatically coupled to a conventional telephone line 64. A user's control device 65 relays the signal to an automatic area control device 66, which in turn automatically transmits by radio to a patrol car, helicopter (67) or fire station 68, where the encoded information is displayed and printed and the voice information is monitored. This arrangement permits a major cost reduction to the user in that hundreds of user's units 65 share a single transmitter in the area control unit.

The user's control unit 65 comprises a message center 69 which accepts input signals from the various sensors (e.g., 2-5) and directs them to a digital encoder 71 for transmission over telephone line 64.

The message center 69 determines which sensor is activating the control unit 65 and determines the digital code to be sent.

The dial tone detector 72 detects the occurrence of a telephone dial tone.

The automatic dialer 73 automatically dials a preselected number.

The busy signal detector 74 automatically resets the circuit back to the detector 72 when the line is busy.

The recorder tone detector 75 determines if the recorder 76 in the area control device 66 is recording and sets back until the recorder 76 is ready.

The digital encoder 71 transmits and resets the circuit back to the message center 69 after the digital code is sent, so that the control unit is again ready for the sender message.

The system test unit 77 periodically tests the operation of the system.

The timer unit 78 in the area control device provides an indication of the time of day when the messages are received.

The teletype printer 79 provides time, station number and message information.

The display unit 81 provides a visual display of the location address.

The speaker 82 is utilized to monitor intrusion noises.

A single receiver 83 and a single transmitter 84 may service a large number of user's control units (e.g., 65) since they are connected to the area control device 66 via standard telephone lines 64. The radio link 85-87 to the police station 22, vehicle 67, and/or fire station 68 is the same as described in the first embodiment.

Still another modification of the system employs the use of a community antenna television office 88 which is directly linked to the output of the user's control unit 65 via CATV, coaxial line 89. The CATV office 88 receives the coded date on line 89 at receiver 91, monitors it by means of display printer 92 and then broadcasts it by means of radio transmitter 93. The broadcast signal is received at the mobile unit (67) in the same manner as the previously described radio link (viz., 85-87).

Thus, the burglary, robbery, emergency and fire sensors, microphone pick up of intrusion noises, prerecorded emergency tape messages, telephone automatic dialing, touch-tone and card dialer devices are automatically coupled to a conventional telephone line by a novel user's control device 65 and relayed directly to police stations 22, fire stations 68, community antenna television headquarters 88 and private patrols where the encoded information is displayed and printed, and the voice information is monitored on speakers. Voice communication may be established with mobile units in the manner previously described.