Electronic security seal

• US 6,265,973 B1
• Filed: 04/16/1999
• Issued: 07/24/2001
• Est. Priority Date: 04/16/1999
• Status: Expired due to Term

• Current Assignee: E J Brooks Company
• Original Assignee: Trans Guard Industries, Inc. (Tyden Group, Inc.)
• Inventors: Hamilton, Craig, Stevenson, David L., Warner, Jeffrey, Brammall, Terrence N., Gilbert, Stanley
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): LA, ANH V
• Application Number:
  US09/293,135
• Time in Patent Office: 830 Days
• Field of Search: 340/539, 340/568.1, 340/571, 340/540, 340/541, 340/542, 70/38.A, 70/38.B
• US Class Current: 340/568.1
• CPC Class Codes: B60R 2025/1016 Remote signals alerting owner or authorities, e.g. radio signals
• CPC Class Codes: B65D 2203/10 Transponders
• CPC Class Codes: B65D 2211/00 Anti-theft means
• CPC Class Codes: B65D 90/00 Component parts, details or accessories for large containers B65D88/34 - B65D88/78 take precedence
• CPC Class Codes: B65D 90/22 Safety features floating covers B65D88/34; arrangements of indicating or measuring devices B65D90/48; fire-fighting A62C
• CPC Class Codes: G09F 3/0317 having bolt like sealing means means for preventing relative axial movement of a pin, spigot, shaft or the like and a member surrounding it F16B21/00
• CPC Class Codes: G09F 3/0335 using RFID tags
• CPC Class Codes: Y10T 70/459 Both legs engaged
• CPC Class Codes: Y10T 70/461 Short leg engaged

Abstract

A molded transparent thermoplastic housing has a programmable transmitting circuit for transmitting seal identifying serial number, seal location, container identification and other data to a local receiver. A door in the housing permits access to the circuit for programming the seal indicia and related data for transmission. A contact arrangement forms a switch upon insertion of a locking bolt into a locking mechanism in the housing and applies battery power through the bolt to activate the data generating circuit. A conductor along the bolt shank is connected to the circuit provides a tamper evident signal to the circuit when the bolt is severed. The circuit senses the removal of the bolt or severed bolt condition for generating a “tamper” signal which is transmitted to a local receiver/reader. The conductor at the bolt may be a wire in a plastic tube surrounding the shank, a conductive layer over an insulation layer on the shank and over the conductive bolt head in ohmic contact with the head or a wire in a hollow metal tube. Severing the bolt severs the wire or the ohmic contact between the head and coating or between the head and the wire in the tube to indicate tampering. The seal periodically in random periods transmits the seal condition, whether normal or tampered. In an alternative embodiment, an interrogation unit may interrogate the seal which then transmits its locked or tampered states according to the locked or tampered condition of the bolt.

Claims

1. An electronic seal comprising:

a housing having a cavity;

an electrically conductive bolt having an elongated shank and a head;

signal generating means in the cavity;

a first electrically insulating layer over at least a portion of the shank;

an electrically conductive layer over at least a portion of the insulting layer and at least a portion of the electrically conductive layer in ohmic contact with the head forming a continuous electrical conductor with the bolt;

bolt locking means in the cavity for receiving and locking the shank to the housing; and

circuit means in the cavity responsive to the received locked shank in ohmic contact with the shank and with the electrically conductive layer, the conductive layer and shank completing an electrical circuit with the circuit means to cause the signal generating means to generate a first signal manifesting a first code and a locked seal and a second signal manifesting a second code and a tampered condition when the shank is severed.

2. The seal of claim 1 further including a second electrically insulating layer over at a portion of the electrically conductive layer over the shank.

3. The seal of claim 2 wherein the second electrically insulating layer extends over and completely covers the electrically conductive layer on said head.

4. The seal of claim 1 wherein the second insulating layer has an interface with the housing for moisture sealing the interface.

5. The seal of claim 1 wherein said housing includes an opening for receiving means for programming said circuit means with seal identifying data, said housing including a door for selectively closing the opening, said door including a bolt receiving recess for locking the door closed in response to said received locked shank engaged with said recess.

6. The seal of claim 1 wherein said circuit means includes contact means for engaging said received locked shank for electrically coupling an electrical power source to the shank and electrically conductive layer.

7. The seal of claim 1 wherein the circuit means includes transmitting means for transmitting the first and second signals.

8. The seal of claim 1 wherein the bolt locking means comprises a body secured in the cavity, a recess in the body and a ring segment in the recess, the shank including a groove for engaging the ring segment for locking the shank to the body.

9. The seal of claim 1 wherein the circuit means includes sense means for causing said second signal to be generated upon sensing interruption of said continuous electrical conductor.

10. The seal of claim 6 wherein said contact means comprises a support, a first contact on the support and a resilient second contact secured to the support releaseably engaged with the received shank and ohmically connected to the first contact.

11. The seal of claim 10 wherein the second contact is serpentine.

12. The seal of claim 10 wherein the second contact is S-shaped.

13. The seal of claim 1 wherein the circuit means includes an electrical circuit comprising a first contact for ohmically engaging the shank and a second contact for ohmically engaging said conductive layer, means for applying electrical power from a source to said circuit means through the bolt and electrically conductive layer for activating the circuit means, the interruption of the electrical circuit for causing the circuit means to generate said second code.

14. The seal of claim 1 further including transmission means and receiver means, said receiver means including means response to an interrogation signal for causing said transmission means to transmit said first or second codes.

15. The seal of claim 1 including transmission means for transmitting said first or second signals.

16. The seal of claim 15 including means responsive to an applied input signal for causing the transmission of said first and second signals.

17. An electronic seal comprising:

a housing having a cavity;

an electrically conductive bolt having a shank and a head;

a locking mechanism fixed in the cavity for receiving and locking the received shank in the cavity;

an electrically conductive layer extending over and along the received shank electrically insulated from the shank and located within and externally the housing;

a circuit in the cavity ohmically coupled to the conductive layer and to the shank for generating a first code signal manifesting a locked state of the bolt and for generating a second code signal manifesting a tampered state of the bolt upon severance of at least one of the conductive layer and shank; and

a transmitter in the cavity responsive to the code signals for transmitting a signal manifesting the codes.

18. The seal of claim 17 including a door secured to said housing for enclosing an opening to the cavity, said circuit including means responsive to programming means inserted through said opening for causing said circuit to generate a seal identifying code included in said first and second codes, and a locking arrangement for locking the door shut upon the locking of said received shank.

19. The seal of claim 17 including a contact responsive to the received shank for applying an energizing signal to said circuit and activating the transmitter.

20. The seal of claim 17 including a battery in said cavity for supplying electrical power to said circuit and transmitter.

21. In a seal comprising a housing, a locking body and a circuit for transmitting the normal or tampered state of the seal when a locking bolt electrically coupled to the circuit used with the seal is tampered with, the locking bolt comprising:

an elongated metal electrically conductive member having a shank for locking engagement with the locking body and an enlarged head at one end of the shank, the shank for engaging a first circuit contact;

an electrical insulating coating over the shank; and

a metal electrically conductive coating over the insulating coating for ohmic connection to a second circuit contact, the conductive coating in ohmic contact with the head such that the shank and coating form a continuous electrical conductor.

22. An electronic seal comprising:

a housing having a cavity;

a bolt having an elongated shank and a head;

signal generating means in the cavity;

bolt locking means in the cavity for receiving and locking the shank to the housing; and

circuit means in the cavity responsive to the received locked shank for causing the signal generating means to generate a first signal manifesting a first code and a locked seal and a second signal manifesting a second code and a tampered condition when the shank is severed;

said housing having an opening for receiving means for programming said circuit means with seal identifying data, said housing including a door for selectively closing the opening, said door including a bolt receiving recess for locking the door closed in response to said received locked shank engaged with said recess.