Patent Publication Number: US-7916016-B2

Title: Smart container monitoring system

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation In Part of U.S. patent application Ser. No. 10/228,842, filed Aug. 27, 2002, now U.S. Pat. No. 6,753,775 entitled “SMART CONTAINER MONITORING SYSTEM”, a National Phase application of PCT Patent Application No. PCT/IL2006/000224, filed Feb. 21, 2006 and a Continuation of U.S. patent application Ser. No. 11/078,240, entitled “SMART CONTAINER MONITORING SYSTEM”, filed Mar. 10, 2005, now U.S. Pat. No. 7,411,495 the disclosures of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to shipping and transportation of goods and more particularly to remotely monitorable shipping containers. 
     BACKGROUND OF THE INVENTION 
     The following U.S. Patents are believed to represent the current state of the art: 
     U.S. Pat. Nos. 4,750,197; 5,056,837; 5,097,253; 5,127,687; 5,169,188; 5,189,396; 5,406,263; 5,421,177; 5,587,702; 5,656,996 and 6,069,563. 
     SUMMARY OF THE INVENTION 
     The present invention seeks to provide an improved remotely monitorable shipping container. 
     There is thus provided in accordance with a preferred embodiment of the present invention, a remotely monitorable shipping container including a shipping container body having associated therewith at least one door and at least one door latch having a latch locking element arranged for locking engagement with a door mounted locking element, at least one wireless communicator mounted in a secure location within the shipping container and being operative to wirelessly transmit information to a remote monitor regarding the status of an electronic seal mounted onto the locking element for confirming locking of the at least one door, and at least one wireless antenna mounted within a protected enclosure on the outside of the shipping container for transmitting the information from the at least one wireless communicator. 
     In accordance with a preferred embodiment, the at least one wireless communicator includes a transceiver. Preferably, the latch locking element includes a tamper-resistant remotely monitorable electronic seal including a shaft portion, a socket arranged to engage the shaft portion in a monitorable manner, whereby disengagement of the socket and the shaft portion results in a monitorable event, and a wireless communicator associated with at least one of the shaft portion and the socket and being operative to provide a remotely monitorable indication of the monitorable event. 
     In accordance with another preferred embodiment, the remotely monitorable shipping container also includes at least one sensor operative to sense at least one condition within the shipping container and wherein the at least one wireless transmitter and the at least one wireless antenna are operative to wirelessly transmit information regarding an output of the at least one sensor to a remote monitor. Preferably, the at least one sensor senses at least one of motion, carbon dioxide, infra-red emissions and temperature. Additionally, the at least one wireless communicator also transmits information regarding the status of the cargo, which is placed in the shipping container body. 
     In accordance with yet another preferred embodiment, the remotely monitorable shipping container also includes at least one GPS antenna for receiving signals relating to location of the shipping container and location reporting circuitry responsive to an output from the at least one GPS antenna for providing information to the at least one wireless communicator indicating location of the shipping container. Preferably, the at least one wireless communicator includes at least one RF transmitter. Additionally, the at least one wireless communicator includes at least one long range transmitter. Preferably, the at least one wireless communicator includes a transmitter communicating via at least one of cellular, radio and satellite communication networks. 
     There is also provided in accordance with a preferred embodiment of the present invention, a shipping container communications system which includes a remotely monitorable shipping container including a shipping container body having associated therewith at least one door and at least one door latch having a latch locking element arranged for locking engagement with a door mounted locking element, at least one wireless communicator mounted in a secure location within the shipping container and being operative to wirelessly transmit information to a remote monitor regarding the status of an electronic seal mounted onto the locking element for confirming locking of the at least one door, and at least one wireless antenna mounted within a protected enclosure on the outside of the shipping container for transmitting the information from the at least one wireless communicator. The shipping container communications system also includes at least one remote communicator communicating with the at least one wireless communicator. Preferably, the at least one wireless communicator includes at least one transceiver, communicating with the at least one remote communicator. Additionally, the at least one remote communicator includes at least one of a presence sensor and communicator, a remote monitor, and an electronic seal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: 
         FIG. 1  is a simplified illustration of a shipping container communications system constructed and operative in accordance with a preferred embodiment of the present invention; 
         FIG. 2  is a simplified illustration showing sealing engagement of a door lock handle of a shipping container of the type illustrated in  FIG. 1 ; 
         FIG. 3  is a sectional illustration taken along lines III-III of  FIG. 2 ; 
         FIG. 4  is a simplified illustration showing an alternative embodiment of sealing engagement of a door lock handle of a shipping container of the type illustrated in  FIG. 1 ; 
         FIG. 5  is a simplified illustration of a shipping container communications system constructed and operative in accordance with another preferred embodiment of the present invention; 
         FIGS. 6A and 6B  are simplified pictorial illustrations of two stages in the assembly of a press-fit electronic seal particularly useful as a tamper resistant remotely monitorable electronic seal of the type illustrated in  FIG. 4 ; 
         FIGS. 7A and 7B  are simplified pictorial illustrations of two different types of breaks produced in the press-fit electronic seal of  FIGS. 5A and 5B ; 
         FIGS. 8A and 8B  are simplified pictorial illustrations of two stages in the assembly of a lockable electronic seal particularly useful as a tamper resistant remotely monitorable electronic seal of the type illustrated in  FIG. 4 ; 
         FIGS. 9A and 9B  are simplified pictorial illustrations of two different types of breaks produced in the lockable electronic seal of  FIGS. 7A and 7B ; 
         FIGS. 10A and 10B  are simplified pictorial illustrations of two stages in the assembly of a press-fit electronic seal particularly useful as a tamper resistant remotely monitorable electronic seal of the type illustrated in  FIG. 4 ; 
         FIGS. 11A and 11B  are simplified pictorial illustrations of two different types of breaks produced in the press-fit electronic seal of  FIGS. 9A and 9B ; 
         FIGS. 12A and 12B  are simplified pictorial illustrations of two stages in the assembly of a lockable electronic seal particularly useful as a tamper resistant remotely monitorable electronic seal of the type illustrated in  FIG. 4 ; and 
         FIGS. 13A and 13B  are simplified pictorial illustrations of two different types of breaks produced in the lockable electronic seal of  FIGS. 11A and 11B . 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     Reference is now made to  FIGS. 1-3 , which illustrate a shipping container communications system constructed and operative in accordance with a preferred embodiment of the present invention. As seen in  FIG. 1 , a shipping container  10 , which may be a conventional shipping container useful for land and sea transport, is shown in communication with multiple communicators, including, for example, a presence communicator  12 , located at the gate of a port, and a remote monitoring center  14 , which may communicate with presence communicator  12  via a network in a wired or wireless manner. It is appreciated that any suitable type of shipping container may be employed. The term “shipping container” is used herein in a very broad sense to include any enclosure in which goods may be transported or stored. 
     Conventionally, shipping containers employ one or more hasps  15 , which are fixed to door latches and are rotatably engageable with corresponding lockable members, such as loops  16 , in the manner shown in  FIGS. 1 and 2 . Typically, a padlock  17  engages a portion of loop  16  which extends through a hasp  15 , preventing disengagement of the hasp  15  from the loop  16  and thus preventing unlocking of the door. In order to confirm integrity of the lock, an electronic seal wire  18  is preferably passed through the loop  16  over the hasp  15 . A preferred electronic seal wire is described and claimed in applicant/assignee&#39;s U.S. Pat. No. 6,069,563, the description of which is hereby incorporated by reference. 
     In accordance with a preferred embodiment of the present invention, first and second plugs  19 , electrically communicating with respective first and second ends of the electronic seal wire  18 , are removably received in respective sockets  20 , which are recessed behind a wall  22  of a container door. 
     In accordance with a preferred embodiment of the present invention, as seen in  FIG. 3 , the sockets  20  communicate with electronic circuitry  23 , which in turn communicates via conductors  24  with RF antennas  26  which are located within an enclosure  28  defined by an outer wall  30  of the container, typically formed of steel, and a cover  32 , preferably formed of plastic or other dielectric material, which does not appreciably attenuate the output of the RF antennas  26 . 
     Preferably, multiple transceivers forming part of circuitry  23  are employed for receiving and transmitting information relating to the integrity of the seal. Each transceiver preferably operates at an RF frequency characteristic of a given part of the world and communicates via corresponding multiple RF antennas  26 . Typical transmission frequencies are 315 MHz for the Far East, 433 MHz for Europe and 916 MHz for the U.S.A. Spread spectrum frequencies may also be employed. It is appreciated that alternatively, unidirectional transmitters may be employed instead of transceivers. The transceivers preferably communicate with electronic seals mounted on the container as well as with external communicators, such as presence communicator  12 , located at the gate of a port and remote monitoring center  14 . Presence sensor and communicator  12  also may communicate with remote monitoring center  14 . 
     Additionally in accordance with a preferred embodiment of the present invention, GPS and GSM antennas  34  and  36  and/or any other suitable type of communications antennas may also be located within enclosure  28  and may communicate with circuitry  23  for transmitting data recorded by circuitry  23  to the remote monitoring center  14  via antennas  26  and  36 . An internal environmental sensor  38 , such as one or more sensor which senses carbon dioxide presence, infra-red emissions, temperature and motion may also communicate with circuitry  23 . Outputs of sensor  38 , which may indicate the presence of contraband within the container may also be transmitted via antennas  26  and  36  for remote monitoring thereof. 
     Reference is now made to  FIG. 4 , which illustrates an alternative embodiment of locking a shipping container in a shipping container communications system constructed and operative in accordance with a preferred embodiment of the present invention. As seen in  FIG. 4 , a shipping container  110 , which may be a conventional shipping container useful for land and sea transport and which may communicate with multiple communicators, employs one or more hasps  115  which are fixed to door latches and are rotatably engageable with corresponding lockable members, such as loops  116 , in the manner shown in  FIGS. 1 and 2 . Here a tamper resistant remotely monitorable electronic seal  117  is employed instead of the padlock  17  described hereinabove with reference to  FIGS. 1 &amp; 2 . The tamper resistant remotely monitorable electronic seal  117 , preferred embodiments of which are described hereinbelow with reference to  FIGS. 6A-13B , engages a portion of loop  116  which extends through a hasp  115 , preventing disengagement of the hasp from the loop and thus preventing unlocking of the door. In order to additionally confirm integrity of the lock, an electronic seal wire  118  is preferably passed through the loop  116  over the hasp  115 . A preferred electronic seal wire is described and claimed in applicant/assignee&#39;s U.S. Pat. No. 6,069,563, the description of which is hereby incorporated by reference. In the illustrated embodiment of  FIG. 4 , the electronic seal wire  118  is encased in a reinforced steel sleeve  119 . 
     In accordance with a preferred embodiment of the present invention, first and second plugs  120  electrically communicating with respective first and second ends of the electronic seal wire  118  are removably received in respective sockets  121  which are recessed behind a wall  122  of a container door. 
     In accordance with a preferred embodiment of the present invention, the sockets  121  communicate with electronic circuitry (not shown) such as circuitry  23  ( FIG. 3 ), which in turn communicates with RF antennas which are located within an enclosure  28  ( FIG. 3 ) defined by an outer wall  124  of the container, typically formed of steel, and a cover  125 , preferably formed of plastic or other dielectric material, which does not appreciably attenuate the output of the RF transmitting antennas. It is appreciated that the tamper resistant remotely monitorable seal  117  may also communicate directly with presence sensor and communicator  12 . 
     Reference is now made to  FIG. 5 , which illustrates a shipping container communications system constructed and operative in accordance with another preferred embodiment of the present invention. As seen in  FIG. 5 , a shipping container  150 , which may be a conventional shipping container useful for land and sea transport, is shown in communication with multiple communicators, including, for example, a presence communicator  152 , located at the gate of a port, and a remote monitoring center  154 , which may communicate with presence communicator  152  via a network in a wired or wireless manner. It is appreciated that any suitable type of shipping container may be employed. The term “shipping container” is used herein in a very broad sense to include any enclosure in which goods may be transported or stored. 
     Conventionally, shipping containers employ one or more hasps  155 , which are fixed to door latches and are rotatably engageable with corresponding lockable members, such as loops  156 , in the manner shown in  FIGS. 5 and 6 . Tamper resistant remotely monitorable electronic seal  157  is employed, and engages a portion of loop  156  which extends through hasp  155 , preventing disengagement of the hasp  155  from the loop  156  and thus preventing unlocking of the door. In order to additionally confirm integrity of the lock, an electronic seal wire  158  is preferably passed through the loop  156  over the hasp  155 . In the illustrated embodiment, the electronic seal wire  158  is encased in a reinforced steel sleeve  159 . A preferred electronic seal wire is described and claimed in applicant/assignee&#39;s U.S. Pat. No. 6,069,563, the description of which is hereby incorporated by reference. 
     In accordance with a preferred embodiment of the present invention, first and second plugs  160 , electrically communicating with respective first and second ends of the electronic seal wire  158 , are removably received in respective sockets  161 , which are recessed behind a wall  162  of a container door. 
     Electronic circuitry (not shown) such as circuitry  23  ( FIG. 3 ), which in turn communicates with RF antennas which are located within an enclosure  28  ( FIG. 3 ) defined by an outer wall  164  of the container, typically formed of steel, and a cover  165 , preferably formed of plastic or other dielectric material, which does not appreciably attenuate the output of the RF transmitting antennas. 
     Additionally in accordance with a preferred embodiment of the present invention, GPS and GSM antennas (not shown) and/or any other suitable type of communications antennas may also be located within the enclosure and may communicate with the electronic circuitry for transmitting data recorded by the electronic circuitry to the remote monitoring center  154  via the RF antennas. 
     In accordance with a preferred embodiment of the present invention, at least one sensor unit  180  is mounted within the shipping container  150 . Sensor unit  180  preferably communicates directly with electronic seal  157 . The electronic seal  157  communicates with remote monitoring center  154 . The electronic seal  157  may communicate with remote monitoring center via presence communicator  152 , via the RF antennas located behind cover  165  or in any other suitable manner. Additionally or alternatively, sensor unit  180 , located within the shipping container  150 , may communicate with a remote communication unit  182  at short range and may also communicate with presence communicator  152 . 
     It is appreciated that sensor unit  180  may be an internal sensor, which may include one or more sensors which sense carbon dioxide presence, infra-red emissions, temperature, motion, seismic waves, acoustic waves and radiation. Sensor unit  180  may additionally or alternatively include any other suitable type of sensor and may also communicate with the electronic circuitry of the shipping container  150 . 
     Reference is now made to  FIGS. 6A and 6B , which are simplified pictorial illustrations of two stages in the assembly of a press-fit electronic seal particularly useful as tamper resistant remotely monitorable electronic seals  117  and  157  in the embodiments of  FIGS. 4 and 5 . 
     As seen in  FIGS. 6A and 6B , there is provided a tamper-resistant electronic seal which preferably comprises a shaft portion  210 , which is integrally formed with or fixed to a sensing circuitry and transceiver portion  212 . Shaft portion  210  preferably has a generally cylindrical configuration and terminates in a press-fit tip  214 , preferably formed with a series of circumferential teeth  216  which are adapted for press-fit engagement with corresponding tooth-like recesses formed in a socket  218 . The press-fit engagement between tip  214  of shaft portion  210  and socket  218  is preferably such that it is impossible to remove the tip  214  from the socket  218  without breaking the shaft portion  210 . 
     Shaft portion  210  preferably includes a weakened frangible portion  220 , located intermediate the sensing circuitry and transceiver portion  212  and the tip  214 . Frangible portion  220  is preferably located closer to sensing circuitry and transceiver portion  212  than to tip  214  and typically has a lesser thickness than the remainder of the shaft portion  210 . 
     A conductive loop  222  preferably extends through shaft portion  210  through to the tip  214  thereof and is configured and mounted in shaft portion  210 , such that breakage of the shaft portion  210  produces a disconnection or significant change in the electrical properties of the conductive loop  222 . 
     In accordance with a preferred embodiment of the present invention, sensing circuitry  224  and an RF transceiver  226  are housed within sensing circuitry and transceiver portion  212 . Sensing circuitry  224  is electrically coupled to conductive loop  222  and senses the integrity thereof. Receiving an output from sensing circuitry  224  is transceiver  226 , which is operative to provide transmitted information indicating whether the conductive loop  222  is intact. Conventional wireless monitoring circuitry (not shown) may be employed to receive information which is transmitted by RF transceiver  226  and indicates tampering with the seal which results in breakage of the shaft portion  210 . 
     Reference is now made to  FIGS. 7A and 7B , which are simplified pictorial illustrations of two different types of breaks produced in the press-fit electronic seal of  FIGS. 6A and 6B . As noted above, application of force to the seal of  FIGS. 7A and 7B  in an attempt to separate shaft portion  210  from socket  218  will not cause tip  214  to be disengaged from socket  218 , without first breaking the shaft portion  210 .  FIG. 7A  shows such a break at a location along the shaft portion  210  which lies just above the tip  214 . It is seen that this break produces a disconnection or significant change in the electrical properties of the conductive loop  222 . 
       FIG. 7B  shows such a break at the frangible portion  220  along the shaft portion  210 . It is seen that this break also produces a disconnection or significant change in the electrical properties of the conductive loop  222 . 
     Reference is now made to  FIGS. 8A and 8B , which are simplified pictorial illustrations of two stages in the assembly of a lockable electronic seal particularly useful as tamper resistant remotely monitorable electronic seals  117  and  157  in the embodiments of  FIGS. 4 and 5 . 
     As seen in  FIGS. 8A and 8B , there is provided a tamper-resistant reusable lockable electronic seal which preferably comprises a shaft portion  310 , which is integrally formed with or fixed to a sensing circuitry and transceiver portion  312 . Shaft portion  310  preferably has a generally cylindrical configuration and terminates in a lockable tip  314 , preferably formed with an undercut groove  315  which is adapted for lockable engagement with a corresponding locking element  316  forming part of a lock  318 , defining a socket, which includes a magnet  319 . Lock  318  is here shown to be a key-operated lock, it being appreciated that any other suitable type of lock may be employed. The locking engagement between tip  314  of shaft portion  310  and locking element  316  is preferably such that without first unlocking the lock, it is impossible to remove the tip  314  from engagement with the locking element  316  without breaking the shaft portion  310 . 
     Shaft portion  310  preferably includes a weakened frangible portion  320 , located intermediate the sensing circuitry and transceiver portion  312  and the tip  314 . Frangible portion  320  is preferably located closer to sensing circuitry and transceiver portion  312  than to tip  314  and typically has a lesser thickness than the remainder of the shaft portion  310 . 
     A conductive loop  322 , including a series connected reed switch  323  which is closed by magnet  319  when shaft portion  310  is in lockable engagement with lock  318 , preferably extends through shaft portion  310  through to the tip  314  thereof and is configured and mounted in shaft portion  310 , such that breakage of the shaft portion  310  produces a disconnection or significant change in the electrical properties of the conductive loop  322 . 
     In accordance with a preferred embodiment of the present invention, sensing circuitry  324  and an RF transceiver  326  are housed within sensing circuitry and transceiver portion  312 . Sensing circuitry  324  is electrically coupled to conductive loop  322  and senses the integrity thereof. Receiving an output from sensing circuitry  324  is transceiver  326 , which is operative to provide transmitted information indicating whether the conductive loop  322  is intact. Conventional wireless monitoring circuitry (not shown) may be employed to receive information which is transmitted by RF transceiver  326  and indicates when the shaft portion  310  is located in lockable engagement with lock  318  and when the shaft portion  310  is separated from lock  318  due to either tampering with the seal, which results in breakage of the shaft portion  310 , or disengagement of shaft portion  310  and lock  318  by using a key to unlock lock  318 . It is appreciated that the provision of reed switch  323  and magnet  319  enables sensing circuitry  324  to sense when the shaft portion  310  is located in lockable engagement with lock  318  and also enables sensing circuitry  324  to sense when the shaft portion  310  is separated from lock  318  for any reason, and allows for recording of engagements and disengagements of shaft portion  310  and lock  318 . 
     Reference is now made to  FIGS. 9A and 9B , which are simplified pictorial illustrations of two different types of breaks produced in the lockable electronic seal of  FIGS. 8A and 8B . As noted above, application of force to the seal of  FIGS. 9A and 9B  in an attempt to separate shaft portion  310  from locking element  316  will not cause tip  314  to be disengaged from locking element  316 , without first breaking the shaft portion  310 .  FIG. 9A  shows such a break at a location along the shaft portion  310  which lies just above the tip  314 . It is seen that this break produces a disconnection or significant change in the electrical properties of the conductive loop  322 . 
       FIG. 9B  shows such a break at the frangible portion  320  along the shaft portion  310 . It is seen that this break also produces a disconnection or significant change in the electrical properties of the conductive loop  322 . 
     It is appreciated that the reed switch and magnet shown in the illustrated embodiments of  FIGS. 8A-9B  can also be used in the embodiments of  FIGS. 6A-7B . 
     Reference is now made to  FIGS. 10A and 10B , which are simplified pictorial illustrations of two stages in the assembly of a press-fit electronic seal particularly useful as tamper resistant remotely monitorable electronic seals  117  and  157  in the embodiments of  FIGS. 4 and 5 . 
     As seen in  FIGS. 10A and 10B , there is provided a tamper-resistant electronic seal which preferably comprises a shaft portion  410 , which is integrally formed with or fixed to a sensing circuitry and transceiver portion  412 . Shaft portion  410  preferably has a generally cylindrical configuration and terminates in a press-fit tip  414 , preferably formed with a series of circumferential teeth  416  which are adapted for press-fit engagement with corresponding tooth-like recesses formed in a socket  418 . The press-fit engagement between tip  414  of shaft portion  410  and socket  418  is preferably such that it is impossible to remove the tip  414  from the socket  418  without breaking the shaft portion  410 . 
     Shaft portion  410  preferably includes a weakened frangible portion  420 , located intermediate the sensing circuitry and transceiver portion  412  and the tip  414 . Frangible portion  420  is preferably located closer to sensing circuitry and transceiver portion  412  than to tip  414  and typically has a lesser thickness than the remainder of the shaft portion  410 . 
     A pair of elongate conductors  422  and  424  preferably extends through shaft portion  410  through to the tip  414  thereof and is configured and mounted in shaft portion  410 , such that breakage of the shaft portion  410  produces a disconnection or significant change in the electrical properties of at least one and preferably both of conductors  422  and  424 . Preferably, conductors  422  and  424  communicate with respective contacts  426  and  428  which are exposed at the end of tip  414  and are arranged to electrically engage an electrical shorting contact  430  at the corresponding interior surface of socket  418  when shaft portion  410  is fully press-fit mounted into socket  418 , thereby defining a conductive loop. 
     In accordance with a preferred embodiment of the present invention, sensing circuitry  432  and an RF transceiver  434  are housed within sensing circuitry and transceiver portion  412 . Sensing circuitry  432  is electrically coupled to conductors  422  and  424  and senses the integrity of a conductive loop which is defined by conductors  422  and  424  when the shaft portion  410  is fully seated in socket  418 . Receiving an output from sensing circuitry  432  is transceiver  434 , which is operative to provide transmitted information indicating whether the conductive loop is intact. Conventional wireless monitoring circuitry (not shown) may be employed to receive information which is transmitted by RF transceiver  434  and indicates tampering with the seal which results in breakage of the shaft portion  410 . 
     Reference is now made to  FIGS. 11A and 11B , which are simplified pictorial illustrations of two different types of breaks produced in the press-fit electronic seal of  FIGS. 10A and 10B . As noted above, application of force to the seal of  FIGS. 11A and 11B  in an attempt to separate shaft portion  410  from socket  418  will not cause tip  414  to be disengaged from socket  418 , without first breaking the shaft portion  410 .  FIG. 11A  shows such a break at a location along the shaft portion  410  which lies just above the tip  414 . It is seen that this break produces a disconnection or significant change in the electrical properties of the conductive loop defined by conductors  422  and  424 . 
       FIG. 11B  shows such a break at the frangible portion  420  along the shaft portion  410 . It is seen that this break also produces a disconnection or significant change in the electrical properties of the conductive loop. 
     Reference is now made to  FIGS. 12A and 12B , which are simplified pictorial illustrations of two stages in the assembly of a lockable electronic seal particularly useful as tamper resistant remotely monitorable electronic seals  117  and  157  in the embodiments of  FIGS. 4 and 5 . 
     As seen in  FIGS. 12A and 12B , there is provided a tamper-resistant lockable electronic seal which preferably comprises a shaft portion  510 , which is integrally formed with or fixed to a sensing circuitry and transceiver portion  512 . Shaft portion  510  preferably has a generally cylindrical configuration and terminates in a lockable tip  514 , preferably formed with an undercut groove  515  which is adapted for lockable engagement with a corresponding locking element  516  forming part of a lock  518 , defining a socket, which includes a magnet  519 . Lock  518  is here shown to be a key-operated lock, it being appreciated that any other suitable type of lock may be employed. The locking engagement between tip  514  of shaft portion  510  and locking element  516  is preferably such that without first unlocking the lock, it is impossible to remove the tip  514  from engagement with the locking element  516  without breaking the shaft portion  510 . 
     Shaft portion  510  preferably includes a weakened frangible portion  520 , located intermediate the sensing circuitry and transceiver portion  512  and the tip  514 . Frangible portion  520  is preferably located closer to sensing circuitry and transceiver portion  512  than to tip  514  and typically has a lesser thickness than the remainder of the shaft portion  510 . 
     A pair of elongate conductors  522  and  524 , at least one of which includes a series connected reed switch  525  which is closed by magnet  519  when shaft portion  510  is in lockable engagement with lock  518 , extends through shaft portion  510  through to the tip  514  thereof and is configured and mounted in shaft portion  510 , such that breakage of the shaft portion  510  produces a disconnection or significant change in the electrical properties of at least one and preferably both of conductors  522  and  524 . Preferably, conductors  522  and  524  communicate with respective contacts  526  and  528  which are exposed at the end of tip  514 . Contacts  526  and  528  are arranged to electrically engage an electrical shorting contact  530  at the corresponding interior surface of lock  518  when shaft portion  510  is in lockable engagement with lock  518 . This electrical engagement, together with the closing of series connected reed switch  525  by magnet  519 , thereby defines a conductive loop. 
     In accordance with a preferred embodiment of the present invention, sensing circuitry  532  and an RF transceiver  534  are housed within sensing circuitry and transceiver portion  512 . Sensing circuitry  532  is electrically coupled to conductors  522  and  524  and senses the integrity of a conductive loop which is defined by conductors  522  and  524  when the shaft portion  510  is in lockable engagement with lock  518 . Receiving an output from sensing circuitry  532  is transceiver  534 , which is operative to provide transmitted information indicating whether the conductive loop is intact. Conventional wireless monitoring circuitry (not shown) may be employed to receive information which is transmitted by RF transceiver  534  and indicates when the shaft portion  510  is located in lockable engagement with lock  518  and when the shaft portion  510  is separated from lock  518  due to either tampering with the seal, which results in breakage of the shaft portion  510 , or disengagement of shaft portion  510  and lock  518  by using a key to unlock lock  518 . It is appreciated that the provision of reed switch  525  and magnet  519  enables sensing circuitry  532  to sense when the shaft portion  510  is located in lockable engagement with lock  518  and also enables sensing circuitry  532  to sense when the shaft portion  510  is separated from lock  518  for any reason, and allows for recording of engagements and disengagements of shaft portion  510  and lock  518 . 
     Reference is now made to  FIGS. 13A and 13B , which are simplified pictorial illustrations of two different types of breaks produced in the lockable electronic seal of  FIGS. 12A and 12B . As noted above, application of force to the seal of  FIGS. 13A and 13B  in an attempt to separate shaft portion  510  from locking element  516  will not cause tip  514  to be disengaged from locking element  516 , without first breaking the shaft portion  510 .  FIG. 13A  shows such a break at a location along the shaft portion  510  which lies just above the tip  514 . It is seen that this break produces a disconnection or significant change in the electrical properties of the conductive loop defined by conductors  522  and  524 . 
       FIG. 13B  shows such a break at the frangible portion  520  along the shaft portion  510 . It is seen that this break also produces a disconnection or significant change in the electrical properties of the conductive loop defined by conductors  522  and  524 . 
     It is appreciated that the reed switch and magnet shown in the illustrated embodiments of  FIGS. 12A-13B  can also be used in the embodiments of  FIGS. 10A-11B . 
     It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove as well as variations and modifications which would occur to persons skilled in the art upon reading the specification and which are not in the prior art.