VEHICLE INTRUSION ALARM SYSTEM

• US 3,688,256 A
• Filed: 04/28/1971
• Issued: 08/29/1972
• Est. Priority Date: 04/28/1971
• Status: Expired due to Term

• Current Assignee: Robert E. Updegraff, Robert F D'Ausilio
• Original Assignee: Robert E. Updegraff, Robert F D'Ausilio
• Inventors: D'Ausilio, Robert F., Updegraff, Robert E.
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/138,221
• Time in Patent Office: 489 Days
• Field of Search: 340/51,63,64,65,224,258,276,280,282,416 325/29,31,37,64,111,113,117,128
• US Class Current: 340/430
• CPC Class Codes: B60R 25/1012 Zone surveillance means, e.g. parking lots, truck depots

Abstract

A vehicle intrusion alarm system protects against the pilferage of vehicles, such as trucks, that remain overnight or longer on parking lot. The system is based on the cooperation between a receiver in the parking lot and a transmitter in the vehicle, said transmitter adapted to be activated by the mere act of opening a vehicle door. As soon as an intruder opens such a door, this action causes the transmitter to produce a changing magnetic field; and a pickup wire of the receiver produces a signal voltage that is used to produce an alarm.

Claims

1. The combination comprising:

a pickup wire, said pickup wire being adapted to produce a signal voltage when exposed to a changing magnetic field;

a vehicle having at least one door, said vehicle being parked adjacent said pickup wire;

transmitter means, associated with said door, for producing a changing magnetic field in the vicinity of said pickup wire when said door is opened, whereby said pickup wire transmits said signal voltage;

receiver means, associated with said pickup wire, for producing an alarm on the occurrence of said signal voltage.

2. The combination of claim 1 wherein said receiver means comprises control means for amplifying said signal voltage.

3. The combination of claim 2 including utilization means for producing an alarm when actuated by said amplified signal voltage from said control means.

4. The combination of claim 3 wherein said pickup wire comprises a pickup loop positioned peripherally around a parking lot.

5. The combination of claim 4 wherein said utilization means comprises a horn.

6. The combination of claim 4 wherein said utilization means comprises a flashing light.

7. The combination of claim 4 wherein said utilization means comprises a rotating-lightbeam, air-patrol light.

8. The combination of clAim 4 wherein said utilization means comprises a self-dialer.

9. The combination of claim 4 wherein said transmitter means comprises a permanent magnet affixed to said door, said permanent magnet having an associated magnetic field that changes the ambient magnetic field at said pickup wire when said door is being opened.

10. The combination of claim 9 wherein said pickup loop comprises a plurality of secondary loops disposed within a given area in parking spaces of said parking lot.

11. The combination of claim 4 wherein said transmitter means comprises a sending loop positioned in said vehicle, pulsing means for causing said sending loop to conduct at least one pulse of electric current that produces a changing magnetic field, and switch means for activating said pulsing means when said door is open.

12. The combination of claim 4 wherein said receiver means includes a circuit protection means, whereby said receiver means protects itself against disablement of said loop.

13. The combination of claim 12 wherein said circuit protection means comprises a capacitor to perform as a low pass filter to reject 60Hz power line interference, a second capacitor, a resistor in conjunction with said second capacitor forming a high pass filter, whereby the combination of said low pass filter and said high pass filter form an effective band pass characteristic.

14. The combination of claim 11 wherein said switch means comprises a magnetic-reed switch mounted on said vehicle in proximity to said door;

and means, comprising a magnet mounted on said door, for holding said magnetic-reed switch in a quiescent condition.

15. The combination of claim 11 wherein said pulsing means comprises timing means for disabling said pulsing means after a predetermined time interval.

16. The combination of claim 11 wherein said pulsing means comprises an oscillator circuit, a flip-flop circuit, means for applying the output of said oscillator circuit to said flip-flop circuit for causing said flip-flop circuit to produce a train of reversing waveforms;

and means for applying said reversing waveforms to said sending loop, whereby said sending loop produces said changing magnetic field.

17. The combination of claim 11 wherein said pulsing means comprises a pulsing circuit having a motor therein and a cam means for controlling said movement of said motor.

18. The combination of claim 11 wherein said switch means includes a plurality of mercury switches centrally positioned at each end of said vehicle.

19. The combination of claim 14 wherein said receiving means includes counting means, and disabling means for causing said counting means to disable said control means for a given time interval, whereby the disabled time interval prevents the production of false alarms.