Abstract:
A support includes a base having an outwardly extending projection with a passageway therethrough, and having a tag receiving portion configured to removably support a tag on the base adjacent one end of the passageway. A different arrangement involves a tag that includes a housing having an opening therethrough and having an annular surface around the opening, an annular gasket engaging the annular surface, and circuitry within the housing having a sensor located in the region of the opening and having a transmitter that can transmit wireless signals. A method includes defining a passageway that provides fluid communication between an interior and exterior of a container, supporting a tag on the exterior of the container, and causing the tag to sense, at a location in the region of an end of the passageway, a condition within the container.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates in general to monitoring of containers during shipment and, more particularly, to monitoring of environmental conditions within a container.  
       BACKGROUND  
       [0002]     It is desirable to be able to monitor items or containers during shipment. One known technique for tracking items or containers is to mount a radio frequency identification (RFID) tag on each item or container to be tracked. These RFID tags can transmit wireless signals, and some tags can also receive wireless signals. Where the object being tracked is a container, there are situations in which it is desirable to be able to monitor one or more environmental conditions within the container, such as the temperature and/or humidity.  
       SUMMARY OF THE INVENTION  
       [0003]     One of the broader forms of the invention relates to an apparatus with a support that includes: a base; a projection extending outwardly from the base in a selected direction and having a passageway therethrough, the passageway having first and second ends respectively adjacent and remote from the base; and a tag receiving portion provided on the base and configured to removably support a tag on the base adjacent the first end of the passageway.  
         [0004]     Another of the broader forms of the invention involves an apparatus with a tag that includes: a housing having a wall portion with an opening therethrough and having thereon an annular surface portion extending around the opening; an annular gasket engaging the annular surface portion; and circuitry disposed within the housing, the circuitry including a sensor located in the region of the opening, and a transmitter that can transmit wireless signals.  
         [0005]     Still another of the broader forms of the invention involves a method that includes: defining a passageway providing fluid communication between an interior and exterior of a container; supporting a tag on the exterior of the container in the region of an outer end of the passageway; and causing the tag to sense, at a location in the region of the outer end of the passageway, an environmental condition within the container.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     A better understanding of the present invention will be realized from the detailed description that follows, taken in conjunction with the accompanying drawings, in which:  
         [0007]      FIG. 1  is a diagrammatic perspective view showing an apparatus that embodies aspects of the present invention, and also showing a wall of a container.  
         [0008]      FIG. 2  is a different diagrammatic perspective view of the apparatus of  FIG. 1 , taken from an opposite side of the container wall.  
         [0009]      FIG. 3  is a diagrammatic exploded perspective view of the apparatus and container wall of  FIG. 1 .  
         [0010]      FIG. 4  is a diagrammatic exploded perspective view: of a tag that is a component of the apparatus of  FIG. 1 .  
         [0011]      FIG. 5  is a diagrammatic perspective bottom view of an upper housing part of the tag of  FIG. 4 , showing some structural components within the upper housing part that are not visible in  FIG. 4 .  
         [0012]      FIG. 6  is a diagrammatic perspective view showing a circuit board that is a component of the tag of  FIG. 4 .  
         [0013]      FIG. 7  is a diagrammatic exploded perspective bottom view of the tag of  FIG. 4 .  
         [0014]      FIG. 8  is a diagrammatic fragmentary bottom view of a portion of the tag of  FIG. 4 .  
         [0015]      FIG. 9  is a diagrammatic perspective view of an alternative embodiment that includes aspects of the present invention, showing the tag of  FIG. 1  with a bracket that can removably support the tag.  
     
    
     DETAILED DESCRIPTION  
       [0016]      FIG. 1  is a diagrammatic perspective view showing an apparatus  10  that embodies aspects of the present invention, and also showing a portion of a wall  12  of a container.  FIG. 2  is a different diagrammatic perspective view of the apparatus  10 , taken from an opposite side of the container wall  12 .  FIG. 3  is a diagrammatic exploded perspective view of the apparatus  10  and the container wall  12 .  
         [0017]     Referring to  FIGS. 1-3 , the container wall  12  is made of metal, and has a circular opening  14  therethrough. The container wall  12  is part of a container or tank used to ship a product. As one example, the U.S. Navy uses metal containers to ship engines, and there is a need to monitor environmental conditions within the container such as temperature and/or humidity. Alternatively, the container  12  could be any of variety of other types of metal containers that are used to ship various different products.  
         [0018]     The apparatus  10  has a support  16  that includes a base plate  18  and a retainer  19 . In the disclosed embodiment, the base plate  18  and the retainer  19  are each made from stainless steel. However, either part could alternatively be made from any other suitable material. The base plate  18  has a circular opening  21  therethrough, with approximately the same diameter as the circular opening  14  through the container wall  12 . The base plate  18  also has two smaller openings  22  and  23  provided near diagonally opposite corners thereof, and the openings  22  and  23  are each internally threaded. The base plate  18  has two flanges  26  and  27  along opposite sides thereof. The flanges  26  and  27  each extend outwardly in a direction away from the container wall  12 , and are each angled slightly inwardly toward the other thereof. As viewed in  FIG. 3 , the upper portion of each flange  26  and  27  is slightly wider than the lower portion thereof.  
         [0019]     The retainer  19  is a stainless steel sheet bent to approximately a U-shape. The upper portions of the angled flanges  26  and  27  engage opposite edges of the retainer  19 , in order to help maintain the retainer  19  on the base plate  18 . The retainer  19  has on one side an outwardly projecting tab  31 , with an opening  32  therethrough. When the retainer  19  is installed on the base plate  18 , the opening  32  in the tab  31  is coaxially aligned with the opening  23  in the base plate  18 . The retainer  19  has a U-shaped slit that defines a resilient leaf spring  34 , for a purpose discussed in more detail later.  
         [0020]     With reference to  FIG. 3 , two strips  37  and  38  of double-sided tape are adhesively secured to the side of the base plate  18  that faces the container wall  12 . The tape strips  37  and  38  serve to adhesively secure the base plate  18  to the container wall  12 , with the openings  14  and  21  in coaxial alignment. The double-sided tape strips  37  and  38  are a type of tape known as VHB (very high bond) tape. In the disclosed embodiment, the tape strips  37  and  38  are obtained commercially as part number  4926  from 3M Corporation of St. Paul, Minn. However, they could alternatively be some other type of tape. Also, instead of using the tape strips  37  and  38 , the base plate  18  could be supported on the container wall  12  in any other suitable manner.  
         [0021]     The support  16  further includes a tubular fitting  46  with a cylindrical passageway  47  extending axially through it. In the disclosed embodiment, the fitting  46  is made of anodized aluminum, but it could alternatively be made of any other suitable material. The fitting  46  has external threads  51  thereon, and an outwardly-projecting annular flange  48  at one end. The end of the fitting  46  remote from the flange  48  has two flat surfaces  53  on diametrically opposite sides thereof, one of which is visible in  FIGS. 2 and 3 . The threaded portion of the fitting  46  extends through the aligned openings  21  and  14  in the base plate  18  and container wall  12 . A nut  57  is provided within the container, and engages the threads  51  of the fitting  46 . The nut  57  has an annular recess  58  on the side thereof facing the container wall  12 . The nut  57  is made of anodized aluminum, but could alternatively be made of any other suitable material.  
         [0022]     The apparatus  10  further includes three annular gaskets  61 ,  62  and  63 , each of which encircles the threaded portion  51  of the fitting  46 . The gasket  61  is disposed between the base plate  18  and the flange  48  on the fitting  46 . The gasket  61  is a nylon washer in the disclosed embodiment, but could alternatively be made from any other suitable material. Since the base plate  18  is made from stainless steel and the fitting  46  is made from anodized aluminum, the gasket  61  serves to maintain a small spacing between the base plate  18  and the flange  48 , in order to avoid corrosion that might otherwise occur as a result of physical contact between dissimilar metals.  
         [0023]     The gasket  62  is disposed between the base plate  18  and the container wall  12 . In the disclosed embodiment, the gasket  62  is made of Neoprene, but it could alternatively be made of any other suitable material. The gasket  63  is disposed between the nut  57  and the container wall  12 , and is partially received within the annular recess  58  in the nut  57 . The gasket  63  maintains a small spacing between the nut  57  and the container wall  12 , in order to avoid corrosion that might otherwise occur as a result of physical contact between dissimilar metals. The gasket  63  is made of Neoprene in the disclosed embodiment, but could alternatively be made of any other suitable material. The gaskets  62  and  63  facilitate a fluid seal between the fitting  46  and the container wall  12 , thereby leaving the passageway  47  as the only path of fluid communication through the opening  14  in the container wall.  
         [0024]     The apparatus  10  further includes a radio frequency identification (RFID) tag  110 . The tag  110  can be slidably inserted into and removed from the support  16 , in directions indicated by the double-headed arrow  111  in  FIG. 3 . The tag  110  has openings in diagonally opposite corners, one of which is visible at  112  in  FIG. 3 . When the tag  110  is removably received within the support  16 , the opening  112  in the tag is aligned with the threaded opening  22  in the base plate  18 , and the other opening in the tag is aligned with the threaded opening  23  in the base plate, and also with the opening  32  through the tab  31 . Two not-illustrated screws each extend through a respective one of the openings in the tag  110 , and one of the screws also extends through the opening  32  in the tab  31 . These two screws respectively engage the threaded openings  22  and  23  in the base plate  18 , so as to removably secure the tag  110  within the support  16 , and also removably secure the retainer  19  against movement relative to the base plate  18 . When the tag  110  is removably secured in this manner within the support  16 , the leaf spring  34  on the retainer  19  engages the tag  110 , and resiliently urges the tag in a direction toward the base plate  18 .  
         [0025]     Turning in more detail to the tag  110 , and with reference to  FIG. 3 , the tag  110  has a housing  116 . A knurled cap  117  can be unscrewed and removed in order to provide access to an internal battery compartment of the tag  110 , so that a battery within the compartment can be replaced. A flexible retaining element  123  has one end fixedly secured to the housing of the tag, and has a stopper  122  at its other end. In  FIG. 3 , the stopper  122  is removably inserted in an opening that provides access to an electrical connector for a serial port. Two information labels  126  and  127  are adhesively secured to the exterior of the housing.  
         [0026]      FIG. 4  is a diagrammatic exploded perspective view of the tag  110 . Two further information labels  128  and  129  are visible in  FIG. 4 . The housing of the tag includes an upper housing part  131  and a lower housing part  132 , which are each made of a sturdy plastic material. During assembly of the tag  110 , the lower housing part  132  is ultrasonically bonded along the entire length of its peripheral edge to the upper housing. part  131 .  
         [0027]      FIG. 5  is a diagrammatic perspective bottom view of the upper housing part  131 , showing some structural components within the upper housing part that are not visible in  FIG. 4 . In this regard,  FIG. 5  shows a battery compartment  136  within the upper housing part  131 . As discussed above, a battery within this compartment can be replaced by removing the knurled cap  117  ( FIG. 4 ).  FIG. 5  also shows a main circuit board  137  and beeper circuit board  138  that are each mounted within the upper housing part  131 . An opening  141  in the upper housing part  131  has therein the previously-mentioned electrical connector for a serial interface. The opening  141  of  FIG. 5  removably receives part of the rubber stopper  122  of  FIG. 3 , in order to protect the electrical connector from environmental conditions. The battery in the battery compartment  136  is electrically coupled by not-illustrated wires to the main circuit board  137 , which in turn is electrically coupled by not-illustrated wires to the electrical connector within the opening  141 . The main circuit board  137  is also coupled by not-illustrated wires to the beeper circuit board  138 .  
         [0028]      FIG. 6  is a diagrammatic perspective view showing the main circuit board  137 , and in particular showing a side thereof opposite from the side that is visible in  FIG. 5 .  FIG. 6  shows that one end of the main circuit board  137  has a conductive loop  146 , which serves as an antenna. The circuitry on the main circuit board  137  includes a transmitter circuit of a known type, which uses the loop antenna  146  to send and receive wireless signals.  
         [0029]      FIG. 7  is a diagrammatic exploded perspective bottom view of the tag  110 . Three additional information labels  161 - 163  are visible on the bottom part  132  of the housing.  FIG. 7  shows an opening  166  that extends through the bottom part  132  of the tag housing  116 . With reference to  FIGS. 4 and 7 , the inner side of the bottom housing part  132  has a shallow circular recess  171  that is approximately concentric to the opening  166 . An annular gasket  172  is provided in the recess  171 , and engages an annular surface portion that extends around the opening  166 . The gasket  172  has a thickness greater than the depth of the recess  171 . In the disclosed embodiment, the gasket  172  is made from the same type of double-sided tape as the tape strips  37  and  38  (FIG.  3 ), and the adhesive on one side of the gasket  172  secures it to the annular surface portion on the housing part  132 .  
         [0030]     A sheet  173  of filter material is adhesively secured to the inner surface of the housing part  132 , within the central opening through the gasket  172 . The filter sheet  173  is positioned so as to extend across the opening  166  ( FIG. 7 ), on the inner side of the opening. The filter sheet  173  has an adhesive on one side that secures it to the inner surface of the housing part  132 . Thus, any air or other fluid passing through the opening  166  must pass through the filter sheet  173 . In the enclosed embodiment, the filter sheet  173  with adhesive on one side is obtained commercially as part number VE60814 from W. L. Gore and Associates, Inc. of Newark, Del. and Elkton, Md.  
         [0031]     The inner side of the housing bottom part  132  has two posts  177  and  178  that project upwardly from locations along. the peripheral edge of the shallow recess  171 . The housing part  132  also has four bosses provided at angularly spaced locations around the recess  171 , each boss having a threaded opening  181  therein. A sensor circuit board  183  has two openings  186  and  187  therein, which each receive the upper end of a respect one of the posts  177  and  178 . As discussed above, the annular gasket  182  has an adhesive surface on the upper side thereof, and this surface engages and is adhesively secured to an annular surface on the underside of the sensor circuit board  183 . The circuit board  183  has four holes  188  that are each aligned with a respect one of the threaded holes  181  in the bottom housing part  132 . Four not-illustrated screws each extend through a respective one of the holes  188 , and each threadedly engage a respective one of the holes  181 , in order to removably hold the sensor circuit board  183  on the bottom housing part  132 .  
         [0032]     The circuitry on the sensor circuit board  183  includes a backup battery  192 . The backup battery  192  keeps a small section of circuitry supplied with power when the main battery becomes discharged, and also during replacement of the main battery. The circuitry operated by the battery  192  includes a portion that maintains time and date information. An electrical connector  193  is mounted on the sensor circuit board  183 . A ribbon cable  194  extends from the connector  193  to an electrical connector on the main circuit board  137  ( FIG. 5 ).  
         [0033]      FIG. 8  is a diagrammatic fragmentary bottom view of part of the tag  110 . In  FIG. 8 , the above-mentioned the sheet  173  of filter material is visible through the opening  166  in the bottom housing part  132 . Behind the sheet  173  are two sensors  197  and  198 , which are mounted on the bottom side of the sensor circuit board  183  ( FIG. 4 ). The sensors  197  and  198  are not visible in  FIG. 4 , and are shown in broken lines in  FIG. 8  because they are located behind the sheet  173  of filter material. The sensors  197  and  198  are commercially available parts of a known type. In the disclosed embodiment, the sensor  197  measures temperature, and the sensor  198  measures humidity. However, either of these sensors could alternatively measure some other condition.  
         [0034]     With reference to  FIGS. 7 and 8 , the outer side of the bottom housing part  132  has a shallow circular recess  201 , which is approximately concentric to the opening  166 . Near the center of the recess  201  is a shallow sensing recess  203  of samller size. In the disclosed embodiment, the sensing recess  203  has a shape that is approximately an oval. The opening  166  communicates at one end with the sensing recess  203 .  
         [0035]     An annular gasket  206  is provided within the recess  201 , and extends around the sensing recess  203 . The gasket  206  has a thickness greater than the depth of the recess  201 . In the disclosed embodiment, the gasket  206  is made of PORON® foam, and is secured by a suitable adhesive, such as an epoxy adhesive, to an annular surface that extends around the sensing recess  203  within the recess  201 . As discussed above in association with  FIGS. 1 and 3 , when the tag  110  is removably disposed in the support  16 , the leaf spring  34  engages the tag and resiliently urges it toward the base plate  18 . With reference to  FIGS. 7 and 8 , this causes the outer side of the gasket  206  to be resiliently urged against the base plate  18 , thereby effecting a fluid seal around the opening  166 , between the base plate  18  and the bottom housing part  132 .  
         [0036]     The beeper circuit board  138  can be used to generate sound that allows the tag  110  to be located when it is mounted on a container. For example, a person with a handheld device can cause the handheld device to transmit a wireless signal that uniquely identifies the tag  110 , and that instructs the tag to use the beeper circuit board  138  to emit a beeping sound. The person can then walk toward the beeping sound and easily locate the tag  110 .  
         [0037]     As discussed above, the support  16  is designed for use with metallic containers. In particular, in the case of a metallic container, the tag  110  must be disposed outside the metal container in order to be able to reliably transmit and receive wireless signals, but must also be able to monitor conditions within the container. The passageway  47  in the fitting  46  gives the tag  110  access to the interior of a container, so that the tag can monitor interior conditions such as temperature and humidity. In contrast, in the case of non-metallic containers, a different approach can be used.  
         [0038]     More specifically,  FIG. 9  is a diagrammatic perspective view showing the tag  110 , and also showing a bracket  221  that can be used instead of the support  16 . The bracket  221  can be used in association with non-metallic containers, where the tag  110  can reliably transmit and receive wireless signals, even if it is inside the container. In the disclosed embodiment, the bracket  221  is made from the same material as the housing  116  of the tag  110 . However, the bracket  221  could alternatively be made from any other suitable material. The bracket  221  includes a base part  223 . The tag  110  can be inserted into and removed from the base part  223  in directions parallel to the double-headed arrow  224  in  FIG. 9 . The base part  223  has holding portions  226 - 229 , which slidably receive a peripheral flange on the tag  110 , in order to help retain the tag on the bracket  221 . The base part  223  has a resilient tongue  236  with a rib  237  at the outer end. The base part  223  also has an opening  241  therethrough.  
         [0039]     As the tag  110  is slid into the bracket  221 , the tag engages the tongue  236  and moves it away from the position shown in  FIG. 9 , against the inherent resilience of the tongue. Then, when the tag  110  has reached a fully inserted position, the tongue&#39;s inherent resilience moves it partway back toward its original position, so that the rib  237  moves to a position engaging a peripheral edge of the tag. The engagement of the rib  237  with the tag edge prevents the tag from moving out of the bracket  221 . In order to remove the tag  110  from the bracket  221 , the outer end of the tongue  236  is manually pressed, so as to move the rib  237  out of engagement with the edge of the tag. The tag  110  can then be slid out of the bracket  221 .  
         [0040]     Although the bracket  221  of  FIG. 9  is suitable for situations where the tag  110  is to be used inside a non-metallic container, it is also possible to put the tag  110  inside a non-metallic container without the bracket  221 . For example, if Styrofoam or some other material is used within the container as packing material for an item being shipped, the packing material can be configured to have a recess that is shaped to receive the tag and that provides the sensors  197 - 198  with access to the ambient environment in the container.  
         [0041]     The operation of the disclosed embodiments will now be briefly described. With reference to  FIGS. 1-8 , when the apparatus  10  is assembled and mounted on a container wall  12 , the passageway  47  and the opening  166  provide fluid communication from the interior of the container to the temperature and humidity sensors  197  and  198  ( FIG. 8 ), through the sheet  173  of filter material. Consequently, the tag  110  can use the sensors  197  and  198  to monitor the temperature and humidity within the container. The tag  110  can use its transmitter circuit and its loop antenna  146  to transmit wireless signals that include either the measured temperature and humidity, or information relating to these measurements. For example, if the humidity within the container is supposed to remain within a specified range, but the tag  110  measures a humidity level outside this range, the tag can transmit a wireless signal indicating that the humidity is outside the specified range.  
         [0042]     In the embodiment of  FIG. 9 , the opening  241  and the opening  166  provide fluid communication from the temperature and humidity sensors  197  and  198  ( FIG. 8 ) through the filter sheet  173  to the ambient environment externally of the tag and bracket. Consequently, the tag  110  can monitor the ambient temperature and humidity, and can transmit wireless signals that contain the measurements or information relating to the measurements.  
         [0043]     The foregoing discussion uses terms relating to direction and orientation, such as upper, lower, inner, outer, and so forth. These terms are used for convenience and in relation to the particular views in the accompanying drawings, and are not intended to be considered limiting with respect to the scope of protection.  
         [0044]     Although selected embodiments have been illustrated and described in detail, it should be understood that a variety of substitutions and alterations are possible without departing from the spirit and scope of the present invention, as defined by the following claims.