Personal emergency locator system

• US 5,021,794 A
• Filed: 08/15/1989
• Issued: 06/04/1991
• Est. Priority Date: 08/15/1989
• Status: Expired due to Fees

• Current Assignee: Robert A. Lawrence
• Original Assignee: Robert A. Lawrence
• Inventors: Lawrence, Robert A.
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US07/394,011
• Time in Patent Office: 658 Days
• Field of Search: 342/457, 342/56, 342/44
• US Class Current: 342/457
• CPC Class Codes: G01S 13/74 Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
• CPC Class Codes: G01S 5/04 Position of source determined by a plurality of spaced direction-finders
• CPC Class Codes: G08B 21/0222 Message structure or message content, e.g. message protocol
• CPC Class Codes: G08B 21/0247 System arrangements wherein the alarm criteria uses signal strength
• CPC Class Codes: G08B 21/0263 System arrangements wherein the object is to detect the direction in which child or item is located
• CPC Class Codes: G08B 21/028 Communication between parent and child units via remote transmission means, e.g. satellite network
• CPC Class Codes: G08B 3/1083 Pager locating systems

Abstract

The radio transmitter in a miniaturized transceiver concealed on a person to be located, such as a lost child, is activated and transmits a coded UHF radio homing signal upon receipt of an initiating signal containing the child'"'"'s address code. The initiating signal is automatically transmitted by a repeater station in response to an audible "panic signal" containing the address code and contains the identical address code. The panic signal is a pulse tone produced by a hand held tone generator activated by the child'"'"'s parent and is transmitted to the repeater station by telephone. Tracking vehicles are provided with automatic UHF radio direction finding and distance measuring equipment for locating the source of the homing signal. Stored information concerning the child can be transmitted to the tracking vehicles.

Claims

1. A telephone-activated personal emergency locator system, comprising:

portable signal generating means adapted to be actuated by an individual interested in locating a lost or abducted person, said signal generating means generating an audible digital pulse-tone signal containing a discrete encoded address for transmission by means of a telephone system;

repeated means effectively connected to said telephone system for receiving audible digital pulus-tone signals transmitted by said telephone system, said repeater means including radio transmitter means for generating and transmitting a radio-frequency initiating signal containing said encoded address upon receipt of a digital pulsetone signal from said signal generating means.

radio transceiver means carried by a person to be located for receiving an initiating signal transmitted by said repeater and transmitting a radio homing signal containing said encoded address in response to said initiating signal; and

radio receiver means for receiving and identifying said homing signal and determining there from the bearing and distance from said receiver to said transceiver.

2. The personal emergency locator system of claim 1, wherein said homing signal is in the radio ultrahigh frequency range.

3. The personal emergency locator system of claim 2, wherein said radio receiver includes an automatic direction finder and distance measuring equipment.

4. The personal emergency locator system of claim 3, wherein said radio receiver is mobile.

5. The personal emergency locator system of claim 4, comprising a plurality of such radio receivers.