Proximity indicating system

• US 3,293,600 A
• Filed: 03/23/1964
• Issued: 12/20/1966
• Est. Priority Date: 03/23/1964
• Status: Expired due to Term

• Current Assignee: Gifft, Thomas H.
• Original Assignee: Gifft, Thomas H.
• Inventors: Gifft, Thomas H.
• Application Number:
  US04/354,072
• Time in Patent Office: 1,002 Days
• US Class Current: 340/903
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Claims

1. IN A PROXIMITY INDICATING SYSTEM FOR PRODUCING A WARNING SIGNAL ON EACH ONE OF A PLURALITY OF VEHICLES WHEN SAID VEHICLES COME WITHIN RADIO SIGNAL RANGE OF EACH OTHER, A PLURALITY OF VEHICLES AND A PROXIMITY UNIT ON EACH ONE OF SAID VEHICLES, EACH OF SAID UNITS COMPRISING MEANS FOR GENERATING UNIFORM LONG DURATION PULSES OF RADIO FREQUENCY ENERGY AT A PREDETERMINED FREQUENCY AND AT A RANDOM PULSE RATE, ANTENNA MEANS FOR RADIATING SAID RADIO FREQUENCY ENERGY, RECEIVING MEANS FOR PRODUCING OUTPUT SIGNAL PULSES IN RESPONSE TO THE PULSES TRANSMITTED BY THE UNITS OF OTHERS OF SAID VEHICLES, SAID RECEIVING MEANS BEING CONNECTED TO SAID ANTENNA MEANS, CONTROL MEANS COUPLED TO SAID RADIO FREQUENCY GENERATING MEANS, SAID CONTROL MEANS DISABLING SAID RECEIVING MEANS DURING THE OCCURRENCE OF A PULSE FROM SAID RADIO FREQUENCY GENERATING MEANS, AND MEANS RESPONSIVE TO THE OUTPUT OF SAID RECEIVING MEANS FOR GENERATING A WARNING SIGNAL WHEN SIGNALS ARE RECEIVED BY SAID RECEIVING MEANS FROM UNITS ON OTHER VEHICLES, SAID WARNING SIGNAL GENERATING MEANS INCLUDING DETECTOR MEANS RESPONSIVE TO THE OUTPUT OF SAID CEIVING MEANS, SAID DETECTOR MEANS HAVING AN OUTPUT FOR SIGNALS ABOVE A PREDETERMINED AMPLITUDE AND PULSE LENGTH DISCRIMINATING MEANS CONNECTED TO THE OUTPUT OF SAID DETECTOR MEANS, SAID PULSE LENGTH DISCRIMINATING MEANS RESPONDING ONLY TO PULSES HAVING A PREDETERMINED (LONG) DURATION.