Beacon tracking system
Patent 4021807 Issued on May 3, 1977. Estimated Expiration Date: 
May 3, 1994. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
May 3, 1994. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2951248 2995751 3005200 3366958 3618059 InventorsAssigneeApplicationNo. 05/564510 filed on 04/02/1975US Classes:342/458, Distance340/539.1, Radio340/539.13, Tracking location (e.g., GPS, etc.)340/568.7, Currency, credit card, or container therefor (e.g., wallet or handbag)342/442, Having a phase detector342/445, Having more than two antennas342/465, Plural receivers only455/95Mobile or portableExaminersPrimary: Wilbur, Maynard R.Assistant: Berger, Richard E. Attorney, Agent or FirmAbstractA radio frequency transmitter is hidden within a packet of currency which may be mingled with other currency packets in the cash drawer of a bank, convenience store or other such commercial institution. The transmitter is automatically activated by unauthorized removal from the cash drawer or other place of safekeeping. The signals from the transmitter activate alarms in one or more receivers located in police vehicles in the area. The receivers employ phase comparison techniques to indicate relative direction and distance to the transmitter thereby facilitating apprehension of the possessor of the packet.Other References
| |
