ELECTRONIC FENCE VEHICLE LOCATER TRANSMITTER AND SYSTEM USING SAME

• US 3,735,335 A
• Filed: 12/20/1971
• Issued: 05/22/1973
• Est. Priority Date: 12/20/1971
• Status: Expired due to Term

• Current Assignee: Gerald Stanley Kaplan, Joshua Shefer
• Original Assignee: Gerald Stanley Kaplan, Joshua Shefer
• Inventors: Shefer, Joshua, Kaplan, Gerald Stanley
• Primary Examiner(s): Tubbesing, T. H.
• Application Number:
  US05/209,961
• Time in Patent Office: 519 Days
• Field of Search: 343/6R,6.5R,6.5LC,112TC 340/23
• US Class Current: 340/991
• CPC Class Codes: G08G 1/127 to a central station ; Indicators in a central station
• CPC Class Codes: G08G 1/20 Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles

Abstract

A vehicle location system in which two different messages are sent in opposite directions from a common vehicle locator transmitter. Vehicle location and direction is determined by the vehicle storing the different messages and, when interrogated, replying with a message that indicates on which side of the vehicle locator transmitter the vehicle is located.

Claims

1. In a vehicle location system of the type wherein a plurality of vehicle locator transmitters are distributed about a given area so that a central station having a transceiver can determine the location of vehicles which contain mobile transceivers and vehicle location receivers, said vehicle location transmitter transmitting coded messages, said vehicle receiver responsive to said coded messages for storing said message, said mobile transceiver coupled to said vehicle receiver and being responsive to an interrogation message from said central station for transmitting said coded message in said vehicle receiver to said central station indicating vehicle location, an improvement in the vehicle location transmitter of the system comprising:

means for generating a plurality of messages with each message identifying different subareas or zones in said given area, means responsive to said generating means for transmitting from a common location each of said plurality of messages with a different messages sent to each zone.

2. The combination claimed in claim 1 including means coupled between said generating means and said transmitting means for transmitting said messages sequentially.

3. The combination claimed in claim 1 wherein said plurality of messages is two and said messages are transmitted in opposite directions.

4. The combination claimed in claim 3 wherein said transmitting means further includes a pair of horn antennas with their output ends facing in opposite directions.

5. The combination claimed in claim 1 wherein said transmitting means includes a single microwave generator.