VEHICLE ALERTING SYSTEM

• US 3,673,560 A
• Filed: 05/21/1970
• Issued: 06/27/1972
• Est. Priority Date: 05/21/1970
• Status: Expired due to Term

• Current Assignee: James N. Edwards, Max K. Barsh
• Original Assignee: James N. Edwards, Max K. Barsh
• Inventors: Barsh, Max K., Edwards, James N.
• Primary Examiner(s): Cooper, William C.
• Application Number:
  US05/039,493
• Time in Patent Office: 768 Days
• Field of Search: 340/32-34
• US Class Current: 340/901
• CPC Class Codes: G08G 1/0965 responding to signals from another vehicle, e.g. emergency vehicle

Abstract

Disclosed is a system for alerting persons in vehicles of the presence in their vicinity of vehicles devoted to responding to emergency situations; the former may be passenger automobiles, buses or other means of public transportation, etc. and the latter may be police cars, fire trucks, ambulances or the like. The system comprises a complete radio station installation in each emergency vehicle and a receiver installation in each passenger vehicle, and both installations may utilize much of the radio equipment already found in such vehicles for other purposes. Thus, in the passenger vehicle, the equipment may comprise an adapter operative to override any normal reception of the car radio to provide an audible and/or visible indication, or a separate indicating receiver of minimum complexity, whereas, in the emergency vehicle, the equipment may comprise a separate modem or one multiplexed to equipment ordinarily serving another function. In the preferred form, the emergency vehicle modem includes a coder-transmitter and a receiver-decoder-indicator both multiplexed to the same antenna, and the passenger vehicle receiver is similar to the receiving equipment of the emergency vehicle.

Claims

1. In an alarm system for emergency vehicles, a plurality of transmitter sections, each said transmitter section comprising:

an antenna;

a transmitter connected to excite said antenna;

signal generating encoder means for modulating said transmitter, said encoder means having a different duty cycle than, and being adapted to operate in non-synchronism with respect to the signal generating encoder means of any other transmitter section in said system.

2. The system of claim 1 wherein said encoders operate at different duty cycles.

3. The system of claim 1 and an indicator responsive to said encoder to indicate excitation of said transmitter and antenna.

4. The system of claim 1 and a receiver section responsive to the signals from the transmitter seCtions of other vehicles.

5. The system of claim 4 and an indicator responsive to excitation of said receiver section.

6. The system of claim 4 and means to cut off response to said receiver section during operation of said encoder.

7. The system of claim 4 and a multiplexer operative to provide selective operation of said antenna by said transmitter and said receiver section.

8. The system of claim 5 wherein said indicator operates both visual and aural outputs.

9. The system of claim 5 and second means also responsive to excitation of said receiver section to indicate outside of the vehicle.

10. An alarm system for a substantially enclosed area such as a vehicle, capable of indicating the presence of an emergency, adapted for use in a fleet comprising both emergency and receiving vehicles, said system comprising:

in the receiving vehicle, an antenna, a receiver, a decoder and an indicator; and

in each emergency vehicle, an antenna, a transmitter, a signal generating encoder means for modulating said transmitter, said encoder means having a different duty cycle than, and being adapted to operate in non-synchronism with respect to, the signal generating encoder means of any other transmitter section in any other emergency vehicle, a receiver, a decoder, means to inhibit operation of said emergency vehicle receiver when said emergency vehicle encoder is operated and means to multiplex said emergency vehicle antenna between said emergency vehicle transmitter and receiver.