Abstract:
A vent cover ( 16 ) for installing on a shipping container. The vent cover includes a housing ( 16   a ) adapted for covering a vent hole ( 24 ) of the shipping container. A direct current (DC) power source is encased or enclosed in the housing. The DC power source includes a battery. The vent cover may also include a circuit board ( 34 ) attached to the DC power source. An antenna ( 36 ) may be located on a surface of the housing and attached to the circuit board. The circuit board may include a satellite antenna interface for a satellite antenna and a global positioning system (GPS) module attached to the satellite antenna interface. The vent cover may include an environmental sensor ( 304 ) for sensing a parameter of the shipping container. The environmental sensor may be adapted to protrude through a hole in a wall ( 12 ) of the shipping container when the vent cover is mounted on the shipping container. The electromagnetic sensor may be configured to transmit an electromagnetic signal ( 324 ) and sense an electromagnetic response signal ( 322 ) responsive to the transmitted wave and sensitive to variations within the container.

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to securing a shipping container and its contents against theft or intrusion and logistics management of containers&#39; locations around the world. 
     2. Description of Related Art 
     Shipping containers are used to transport goods all over the world. Many shipping containers are monitored to maintain a log of their whereabouts, as well as to monitor their estimated time of delivery to a given port or destination. There are millions of shipping containers in use today, and they typically transport billions of dollars worth of goods around the globe. 
     Reference is now made to  FIG. 1  which shows a rectangular shipping container  10 , according to conventional art. Typically containers  10  are made in varying shapes, sizes and specifications in order to best transport goods or items being shipped. Beams  14  connect sides  12  to roof and floor of container  10  and provide for the mounting of access doors  18 . Doors  18  are used to access the space where goods/items are stored prior to transportation. Sides  12  may be corrugated and typically the space between corrugations is used to locate a vent cover  16 . Vent cover  16  is typically located in a space between corrugations to avoid damage to vent cover  16 . Vent cover  16  may also be located on side  12  near to doors  18 . A purpose of vent cover  16  is to cover ventilation holes  24  (not shown) which typically provide ventilation between the interior and exterior of container  10 . 
     Reference is now made to  FIG. 2  which shows a closer isometric view  20  of vent cover  16  mounted on side  12  of container  10 . Vent cover  16  is attached to side  12  between protruding sections of side  12  using mechanical fasteners  22 . Fasteners  22  may typically be rivets or nuts and bolts. Vent cover  16  may additionally be more hermetically attached to side  12  with a silicone sealant or gasket arrangement placed between wall  12  and vent cover  16 . The silicone sealant or gasket serves to stop water (rain or sea water) for example from getting into container  10  via vent holes  24  (shown in dotted lines) in container wall  12  behind vent cover  16 . Vent holes  24  are through-holes in side  12  which provide ventilation and/or pressure equalization between the interior and exterior of container  10 . Holes  24  may be covered with a gauze filter, semi-breathable membrane or restricted to a certain size. Holes  24  allow the escape of any gases built up inside container  10  as well as to regulate temperature or humidity inside container  10  for example. Vent cover  16  typically provides additional protection of contents inside container  10  from the environment outside container  10 . Vent cover  16  may also have ventilation slots  26  at the bottom of vent cover  16  to allow air flow to and from holes  24 . 
     The term “enclosed” as used herein refers to closing with a closure which may be opened or disassembled after use. 
     The term “encased” as used herein refers to permanently encasing such as by casting and curing a resin with an object inside. 
     The terms “vent” and “vent hole(s)” are used herein interchangeably to refer to one or more openings in the shipping container which allows transfer of gas between the interior and exterior of the shipping container. 
     BRIEF SUMMARY 
     According to embodiments of the present invention, there is provided a vent cover for installing on a shipping container. The vent cover includes a housing adapted for covering a vent hole of the shipping container. A direct current (DC) power source is encased or enclosed in the housing. The DC power source includes a battery. The DC power source e.g. replaceable battery, may be enclosed in the housing. Alternatively, the DC power source may be encased in the housing and the DC power source may be a rechargeable battery. The rechargeable battery may be chargeable by mutual inductance through the housing or any other charging methods, for example: a solar panel. The vent cover may also include a circuit board operatively attached to the DC power source. An antenna may be located on a surface of the housing and operatively attached to the circuit board. The circuit board may include a satellite antenna interface for a satellite antenna and a positioning module such as global positioning system (GPS) module attached to the satellite antenna interface. The circuit board may also include a second antenna interface and a communications transceiver attached to the second antenna interface. The vent cover may include an environmental sensor for sensing a parameter of the shipping container. The environmental sensor connected to the circuit board may be adapted to protrude through a hole in a wall of the shipping container when the vent cover is mounted on the shipping container. The environmental sensor may be an electromagnetic sensor, thermal, humidity, motion sensor, gas sensor, pressure sensor, optical sensor and/or acoustic sensor. The electromagnetic sensor may be configured to transmit an electromagnetic signal and sense an electromagnetic response signal responsive to the transmitted electromagnetic signal. A wavelength of the transmitted electromagnetic signal may be selected to correspond to a full-wave, half-wave or quarter-wave of a dimension of the container so that the container responds to the transmitted wave as an electromagnetic cavity and the electromagnetic response is sensitive to variations within the cavity. 
     According to embodiments of the present invention there is provided a vent cover for installing on a shipping container. The vent cover includes a housing adapted for attaching over a vent hole of the shipping container. An electromagnetic sensor extends from the housing and is adapted to transmit an electromagnetic signal and sense an electromagnetic response signal responsive to the transmitted electromagnetic signal. A wavelength of the transmitted electromagnetic signal is selected to correspond to a full-wave, half-wave or quarter-wave of a dimension of the container so that the container responds to the transmitted wave as an electromagnetic cavity and the response electromagnetic is sensitive to variations within the cavity. 
     According to embodiments of the present invention there is provided a method for securing a shipping container. An electromagnetic signal is transmitted into a space of the shipping container. A response signal is sensed which is responsive to the electromagnetic signal in the space and based on the response signal a potential theft may be alerted. The transmitting and the sensing may be performed periodically as part of a monitoring mode. During the alert, the monitoring mode is changed to an active mode. In the active mode, the alert of potential theft is communicated by a communication system. The communication system may be a satellite link, a wide area network (WAN), a local area network (LAN), a global system for mobile communications (GSM) gateway, a portable cellular cell or any other communication method. The transmission may be sent and the sensing may be performed using power from a direct current power source encased or enclosed in a housing mounted as a vent cover of a shipping container. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein: 
         FIG. 1  shows a rectangular shipping container , according to conventional art. 
         FIG. 2  shows a closer isometric view of vent cover mounted on the side of the shipping container of  FIG. 1 , according to conventional art. 
         FIG. 3   a  shows an isometric view of a housing used to secure a shipping container, according to an embodiment of the present invention. 
         FIG. 3   b  shows a cross-sectional detail of housing of  FIG. 3   a , according to an aspect of the present invention. 
         FIG. 3   c  which shows a block diagram of a circuit board, according to a feature of the present invention. 
         FIG. 3   d  shows a cross sectional plan view of rectangular container and an electromagnetic signal inside container according to an exemplary embodiment of the present invention. 
         FIG. 3   e  shows a method used to secure a shipping container, according to a feature of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. 
     Before explaining embodiments of the invention in detail, it is to be understood that the invention is not limited in its application to the details of design and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
     By way of introduction, embodiments of the present invention are directed to securing against theft a shipping container and its contents. Embodiments of the present invention may alternatively or in addition be useful for logistics management of shipping containers and/or their contents. According to a feature of the present invention a circuit board and power supply for the circuit board is provided in a housing which looks like vent cover  16  mounted on the side of a shipping container. 
     In embodiments of the present invention the circuit board and the power supply preferably are mounted in a housing as part of injection molding or other manufacturing process used to form the housing or the circuit board and/or power supply is mounted in the housing after manufacture of the housing. Vent holes on the exterior wall of the container may be used to allow sensing of the container interior. The vent holes may be situated at a standard place in the wall of the container or at a non-standard place on the container. The “vent holes” may be drilled, bored or punched or otherwise formed when the vent cover according to embodiments of the present invention is installed on the shipping container. 
     Referring now to the drawings, reference is now made to  FIG. 3   a  which shows an isometric view  30  of a housing  16   a  used to secure a shipping container  10  according to an embodiment of the present invention. Housing  16   a  like vent cover  16  is attached to a container  10  via fasteners  22  and typically also performs the function of allowing air to flow between the interior and exterior through ventilation slots  26 . To an observer, housing  16   a  attached to container  10  looks no different than housing  16  attached to container  10 . Circuit board  34 , battery holder  32  and/or one or more antennas  36  are mounted inside or on surface of housing  16   a  in such a way that housing  16   a  is visually indistinguishable from vent cover  16  when mounted on shipping container  10 . Battery holder  32  typically may hold for instance one or more standard AA or AAA size replaceable batteries or rechargeable batteries such as nickel cadmium (NiCad) types. The batteries, when mounted in battery holder  32 , supply direct current power to circuit board  34  during operation. 
     Reference is now made to  FIG. 3   b  which shows a cross-sectional detail of housing  16   a  according to an embodiment of the present invention. Housing  16   a  is shown attached to flat surface of wall  12  between corrugated sections of wall  12  and mounted on the outside of a shipping container  10 . A transducer  304 , e.g. electromagnetic transducer, is located on the inside of container  10  and is attached to circuit board  34  with cable  306 . Cable  306  connects board  34  to transducer  304  through ventilation hole  24 . Multiple ventilation holes  24  may allow for multiple sensors, transducers or antennas to be located inside container  10  which may be connected to circuit board  34 . Multiple sensors, transducers or antennas located inside container  10  typically may allow for sensing of temperature, humidity, pressure, air quality, motion, along with the removal and placement of objects inside container  10 . 
     Antenna  36  is connected to circuit board  34  and may be disposed on the inside of housing  16   a  (along with board  34  and battery holder  32 ) if housing  16   a  is made from an electrically non-conductive material. If housing  16   a  is made from electrically conductive material such as metal, antenna  36  may be mounted outside the exterior surface of housing  16   a . Antenna  36  is typically located and orientated to allow for either vertical and/or horizontal polarization. Antenna  36  is shown externally on a vertical face of housing  36  by way of example only. One or more antennas  36  may be placed on other external faces of housing  16 , disposed internally within housing  36  and/or as part of circuit board  34 . 
     Circuit board  34 , battery holder  32  and/or batteries (not shown) may be cast inside of housing  16   a  as part of the manufacturing process, e.g. injection molding, of housing  16   a . The manufacturing process, may include use of either thermoplastic or thermoset, e.g. epoxy, urethane materials. Alternatively battery holder  32  and/or circuit board  34  may be mounted inside of housing  16   a  using conventional attachment means known in the art subsequent to injection molding. 
     A mutual inductive coupling  302 , on the inside of housing  16   a , may be used for charging re-chargeable batteries. Coupling  302  may have an aperture  310  which provides a mutual inductive coupling to a secondary magnetic core. Mutual inductive coupling  302  has a secondary winding which is wound around the secondary magnetic core. The secondary winding provides a low voltage alternating current (AC) output when a primary magnetic core (with a primary winding connected to mains electricity) is inserted into the aperture  310  of coupling  302 . The low voltage AC output of the secondary winding is rectified to provide a direct current (DC) used for charging batteries in battery holder  32  when batteries are re-chargeable. Batteries in battery holder  32  may need to be re-charged or replaced prior to the shipping and delivery of a container  10 . When the batteries in battery holder  32  are replaced, typically when container  10  is being reloaded, housing  16   a  is removed from the side of container  10  by unfastening fasteners  22 , the batteries in battery holder  32  are replaced and housing  16   a  is re-attached to container  10  using fasteners  22 . Alternatively, batteries may be recharged using solar and/or wind power from an external power generation device, e.g. solar panel, wind turbine. 
     Reference is now also made to  FIG. 3   c  which shows further details of circuit board  34  according to an aspect of the present invention. Circuit board  34  is powered by batteries placed in battery holder  32 . Circuit board  34  includes an antenna interface  342  which allows one or multiple antennas  36  to be connected to one or more transmitters, receivers and/or transceivers. A single transceiver  341  and a single antenna interface  342  is shown, by way of example only. Transceiver  341  may be for a global system for mobile communications (e.g. GSM transceiver, and/or for a wireless local area network or wireless wide area network. Optionally, a satellite receiver  343  for global positioning system (GPS) may be attached to a port  346  for a satellite antenna externally mounted in or outside housing  16   a . Both satellite receiver  343  and transceiver  341  are operatively connected to a processor  344  (with memory  346  built in and/or attached thereto) along with a sensor interface  345 . Sensor interface  345  allows data to be sent and received from one or multiple sensors  304  located inside container  10 . The data are typically processed by processor  344 . Interface  345  typically may provide the function of sample and hold and appropriate analogue to digital (A/D) and digital to analogue (D/A) conversion of data sent and received between processor  344  and multiple sensors located inside container  10 . 
     Reference is now also made to  FIG. 3   d  which shows a cross sectional plan view  399  of rectangular container  10  and an electromagnetic signal  324  inside container  10  according to an exemplary embodiment of the present invention. Housing  16   a  is mounted between corrugated sections of wall  12 . Walls  12  have a length l which is typically around 12.2 meters and a width w which is typically around 2.4 meters and height h (not shown) typically around 2.5 meters. Items inside container  10  which are to be shipped are shown as items  380   a  and  380   b . Electromagnetic transducer  304  is typically located near a corner of container  10  and is connected to housing  16   a  using cable  306  through one of vent holes  24  (not shown). Transducer  306  connected to processor  344  is used to detect the proximity and movement of objects  380   a ,  380   b . Transducer  306  typically emits an electromagnetic signal or pulse  324  and also senses a change in return signal  322 . Emitted signal  324  typically may be an acoustic signal, an electromagnetic signal or infra red signal. 
     Reference is now made to  FIG. 3   e  which shows a method  301  used to secure a shipping container  10  against theft according to an embodiment of the present invention. Electromagnetic transducer  306  transmits an electromagnetic signal  324  inside container  10  (step  303 ). Step  303  may be performed periodically (once an hour for example) as part of a monitoring mode which is used to save battery power of batteries in holder  32 . An electromagnetic signal may be selected within a frequency band which has a full wave, half-wave or quarter-wave corresponding or similar to one of the dimensions of container  10 , preferably at low power or within a citizen&#39;s band. 
     For example, the frequency of signal  324  which typically corresponds to half a wavelength or a quarter wavelength is determined by either the height (h), length (l) or width (w) of container  10 . If length l of container  10  is 12.2 meters (40 feet) for a wavelength of l4 would give a frequency f determined by Equation Eq. 1.
 
 f =300 /l /4 MHz=1200/12.2 MHz≈10 MHz  Eq. 1
 
     Equation 1 gives approximately, a frequency of approximately 10 MHz for signal  324  for a wavelength l/4 or 6 MHz a for a wavelength of l/2. The choice of 12 MHz or 6 MHz for signal  324  is intended so that the inside of container  10  acts as an electromagnetic wave cavity with respect to signal  324 . A similar estimation may be performed for a container of length 6.1 meters (20 feet). 
     Referring back to  FIG. 3   e , a response signal  322  is sensed (step  305 ) by transducer  306 . Response signal  322  may be sensed in terms of the amplitude and phase or frequency content of response signal  322 . According to an aspect of the present invention steps  303  and  305  may be first performed prior to shipping a container  10 , with the amplitude, phase and/or frequency content of response signal  322  and signal  324  stored in memory  346  in a look-up table as calibration values. Decision  307  may include an evaluation of sensed signal  322 . The evaluation may involve calculating a difference between phase/amplitude/frequency content of transmitted signal  324  and sensed response signal  322 . and comparing with values for response signal  322  and signal  324  previously stored in memory  346  look up table. The evaluation may also further involve consideration from other sensors connected to sensor interface  345  which sense for example humidity, motion, temperature, and shipping container  10  door positioning for example. If the difference is below a certain pre-defined threshold, periodic transmission in monitoring or sleep (power saving) mode (step  303 ) continues. If the difference is above a certain pre-defined threshold, an alert of theft is transmitted (step  309 ) optionally over transceiver  341 , e.g. GSM cellular, and an active mode of operation for circuit board  34  is initiated (step  311 ). The active mode typically may further involve the activation of transceivers  341  and GPS  343  to actively attempt communication with other communication systems such as satellite links, wide area networks (WAN), a local area networks (LAN), global system for mobile communications (GSM) gateway or portable cells or any other communication method. 
     The definite articles “a” or “an” as used herein, such as “a housing”, “a sensor” have the meaning of “one or more” that is “one or more housings” or “one or more sensors”. 
     Although selected embodiments of the present invention have been shown and described, it is to be understood the present invention is not limited to the described embodiments. Instead, it is to be appreciated that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and the equivalents thereof.