FREIGHT SECURITY SYSTEM

• US 3,772,668 A
• Filed: 12/29/1971
• Issued: 11/13/1973
• Est. Priority Date: 12/29/1971
• Status: Expired due to Term

• Current Assignee: William Van Smith
• Original Assignee: William Van Smith
• Inventors: Smith, William Van
• Primary Examiner(s): Trafton, David L.
• Application Number:
  US05/213,703
• Time in Patent Office: 685 Days
• Field of Search: 340/152T,38R,38L,224,309.1,152T,171PF 343/6.5SS 325/8
• US Class Current: 340/8.1
• CPC Class Codes: G01S 13/78 discriminating between different kinds of targets, e.g. IFF-radar, i.e. identification of friend or foe G01S13/75, G01S13/79 take precedence
• CPC Class Codes: G08B 13/2417 having a radio frequency identification chip
• CPC Class Codes: G08B 13/2431 Tag circuit details
• CPC Class Codes: G08B 13/2462 Asset location systems combined with EAS inventory, tracking, logistic G06Q10/00; entrance control systems G07C9/00

Abstract

An electronic security system for safe-guarding freight against theft while in transit and/or while sitting at a dock site. The concept of the system is to plant a unique transceiver in the freight package which responds with a coded signal when properly interrogated, i. e., with a coded radio frequency. The system includes a second transceiver, which is monitored by security personnel, and which is positioned at a strategic location. The monitored transceiver may be automatically triggered each time a conveyance means, e. g., a truck or the like, passes a particular point or it may be triggered manually. Triggering the monitored transceiver causes the transmitted carrier frequency to be modulated with a first coded audio signal. The planted transceiver responds with a second coded signal, if the first signal was of the proper frequency. The monitored transceiver includes a plurality of decoding networks and a plurality of neon lights which respectively respond to signals accepted by the decoding networks. Each light and associated decoding network monitors a separate freight package for purposes of alerting the security personnel when unauthorized movement of the freight package is occurring. The system has the capability of simultaneously safe-guarding numerous packages, e. g., 50 or more, positioned at one location. Additionally, the system is capable of discriminating or pinpointing the particular conveyance means that is carrying the freight package.

Claims

1. An electronic freight security system comprising means positioned at a first location for receiving radio frequency signals, means positioned at said first location for transmitting radio frequency signals, encoder means positioned at said first location for modulating said transmitting means with a first narrow band width predetermined fixed signal, means positioned at said first location for simultaneously triggering said transmitting and said encoder means, means positioned at a location remote from said first location for receiving radio frequency signals, means positioned at said remote location for transmitting radio signals, decoder means positioned at said remote location for responding to said first signal and for passing a narrow width of predetermined frequencies, means positioned at said remote location for amplifying said passed frequencies, encoder means positioned at said remote location for modulating said transmitting means at said remote location with a second narrow band width predetermined fixed signal having a frequency different from said first signal, means positioned at said remote location for discriminatively triggering simultaneously said transmitting means and said encoder means thus causing said remote transmitting means to operate only when said decoder means responds to a signal transmitted from said first location, decoder means positioned at said first location for passing a signal having a narrow width of predetermined frequencies, means positioned at said first location for amplifying the signal passed by said adjacent decoder means, indicator means positioned at said first location, and means positioned at said first location for causing said indicator means to be energized when said decoder means adjacent thereto responds to a signal transmitted from said remote location;

said triggering means positioned at said first location includes activating means, a first relay responsive to said activating means, a resistor, a capacitor, said capacitor being charged when said first relay responds to said activating means and discharges through said resistor, a second relay for simultaneously energizing said encoding means and said transmitting means, and means for coupling said capacitor to said second relay to enable said second relay to be energized by the charge on said capacitor for a predetermined period of time as the charge on said capacitor discharges through said resistor.

2. The system of claim 1 in which said activating means includes a bellows actuated switching means, and an elongated resilient tubular member containing a captured quantity of fluid which is communicated with said switching means for displacing said bellows thereof when said resilient member is squeezably compressed so as to close said switching means.

3. An electronic freight security system for remotely monitoring the physical location of a plurality of freight packages while in transit or while at a dock site comprising means positioned at a first location for receiving radiO frequency signals, means positioned at said first location for transmitting radio frequency signals, encoding means positioned at said frist location for modulating said transmitting means with a first narrow band width predetermined fixed audio signal, means positioned at said first location for simultaneously triggering said transmitting means and said encoder means, means positioned in a plurality of packages at a plurality of locations which are remote from said first location for receiving radio frequency signals, means positioned in each of said packages for transmitting radio signals, decoder means positioned in each of said packages for respectively responding to said first signal and for passing a narrow width of predetermined frequencies, means positioned in each of said packages for respectively amplifying said passed frequencies, encoder means positioned in each of said packages for respectively modulating said transmitting means with a plurality of audio signals of predetermined unique frequencies, means positioned in said packages for respectively triggering said transmitting means and said encoder means thus causing said corresponding transmitting means of said packages to operate only when said decoder means thereof individually responds to a signal transmitted from said first location, a plurality of decoder means positioned at said first location for respectively accepting a plurality of audio signals of predetermined unique frequencies, means positioned at said first location for respectively amplifying the signals passed by said adjacent corresponding decoder means, a plurality of indicator means positioned at said first location, and a plurality of means positioned at said first location for respectively causing said indicator means to be energized when said corresponding decoding means responds to a signal transmitted from said plurality of transmitting means in said packages;

said triggering means positioned at said first location includes activating means, a first relay responsive to said activating means, a resistor, a capacitor, said capacitor being charged when said first relay responds to said activating means and discharges through said resistor, a second relay for simultaneously energizing said encoding means and said transmitting means, and means for coupling said capacitor to said second relay to enable said second relay to be energized by the charge on said capacitor for a predetermined period of time as the charge on said capacitor discharges through said resistor.