RADIO ALARM SYSTEM

• US 3,665,312 A
• Filed: 10/06/1969
• Issued: 05/23/1972
• Est. Priority Date: 10/06/1969
• Status: Expired due to Term

• Current Assignee: Michael Jarvis
• Original Assignee: Michael Jarvis
• Inventors: Jarvis, Michael
• Primary Examiner(s): Safourek, Benedict V.
• Assistant Examiner(s): Mayer, Albert J.
• Application Number:
  US04/864,077
• Time in Patent Office: 960 Days
• Field of Search: 325/51,53,54,55,111,113,117,154,166 340/52,63,64,224,258D 343/5PD,6A
• US Class Current: 455/521
• CPC Class Codes: B60R 25/1025 preventing jamming or interference of said signal
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence
• CPC Class Codes: H04K 2203/22 for communication related to vehicles
• CPC Class Codes: H04K 3/25 based on characteristics of target signal or of transmission as countermeasure against surveillance H04K3/827, e.g. using direct sequence spread spectrum or fast frequency hopping spread spectrum techniques H04B1/69
• CPC Class Codes: H04K 3/827 using characteristics of target signal or of transmission as countermeasure against jamming H04K3/25, e.g. using direct sequence spread spectrum or fast frequency hopping spread spectrum techniques H04B1/69
• CPC Class Codes: H04K 3/88 related to allowing or preventing alarm transmission

Abstract

An alarm and monitoring system for a vehicle in which a transmitter is actuated upon illegal entry into or theft of the vehicle. The transmitter sends out a coded signal, which identifies the vehicle, sequentially on different frequencies with a predetermined and different time interval between each transmission. The received coded signals are used to located the vehicle by triangulation.

Claims

1. An alarm and surveillance system for vehicles for broadcasting signals upon occurrence of a predetermined condition, comprising a normally deenergized means for transmitting radio frequency energy, an antenna electrically coupled to the output of said transmitting means, at least one normally deenergized code generator means electrically coupled to the input of said transmitting means for supplying a coded signal to said transmitting means on a repetitive basis, and means coupled to said transmitting means and said code generator means for actuating the same upon the occurrence of a said predetermined condition, said actuating means comprising an impedance means, means for normally producing a current of a substantially constant value through said impedance means, means responsive to said predetermined occurrence for producing a current change through said impedance means, and means electrically coupled to said impedance means and responsive to said change of current to actuate said transmitting means and said code generator means.

2. The system of claim 1 wherein said code generator means for producing said coded signal operates to produce the coded signal with different time spacings between successive productions of the coded signal.

3. The system of claim 1 wherein said transmitting means includes means for producing a plurality of different carrier frequency signals, and means for successively transmitting the coded signal on different carrier frequencies.

4. The system of claim 3 wherein said code generator means for producing said coded signal operates to produce the coded signal with different time spacings between successive productions of the coded signal.

5. The system of claim 1 further comprising a plurality of receiver stations each having means for receiving signals from a vehicle and for determining the direction from which said signals were transmitted, each receiver including means for decoding the received signals to verify their source, a central station having computer means, and means for supplying data corresponding to the direction from which signals are received from the individual receiver stations to the computer means at said central station.

6. The system of claim 4 further comprising a plurality of receiver stations each having means for receiving signals from a vehicle and for determining the direction from which said signals were transmitted and means for decoding the received signals in response to frequency and spacing, a central station having computer means, and means for supplying data corresponding to the direction from which signals are received from the individual receiver stations to the computer means at said central station.

7. The system of claim 1 wherein said means for producing the current change comprises a circuit tripping means connected to said impedance means which opens at least a portion of the constant current circuit in response to said predetermined occurrence.

8. An alarm and surveillance system for vehicles for broadcasting signals upon occurrence of a predetermined condition, comprising a normally deenergized means for transmitting radio frequency energy, an antenna electrically coupled to the output of said transmitting means, at least one normally deenergized code generator means electrically coupled to the input of said transmitting means for supplying a coded signal to said transmitting means on a repetitive basis, said coded signal having different time spacings between successive productions thereof and said transmitting means including means for producing a plurality of different carrier frequency signals, and means for successively transmitting the coded signal on different carrier frequencies, and means coupled to said transmitting means and said code generator means for actuating the same upon the occurrence of a said predetermined condition, said actuating means comprising an impedance means, means for normally producing a current of a substantially constant value through said impedance means, means responsive to said predetermined occurrence for producing a current change through said impedance means, and means electrically coupled to said impedance means and responsive to said Change of current to actuate said transmitting means and said code generator means.

9. The system of claim 8 wherein said means for producing the current change comprises a circuit tripping means connected to said impedance means which opens at least a portion of the constant current in response to said predetermined occurrence.