Abstract:
A method for encapsulating a monitoring device for a pneumatic tire, wherein the monitoring device includes a threaded rod and a pressure sensor, includes the steps of positioning the monitoring device in an encapsulation chamber of an encapsulation device with a portion of the threaded rod extending from the encapsulation chamber; engaging the threaded rod against the encapsulation device to suspend the electronic monitoring device within the encapsulation chamber; and filling the encapsulation chamber with encapsulation material to encapsulate the monitoring device to form an encapsulated monitoring device. The encapsulated monitoring device may be mounted to a pneumatic tire with an attachment patch.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation-in-part application of U.S. Pat. No. 6,516,673, which is a division of U.S. Pat. No. 6,386,254, which is a division of U.S. Pat. No. 6,161,430; the disclosures of each are incorporated herein by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Technical Field  
           [0003]    The present invention generally relates to an encapsulation device and, more particularly, to an encapsulation device that is used to encapsulate a monitoring device or tire tag that is typically used on the inner surface of a pneumatic tire to monitor tire conditions while the tire is mounted on a vehicle. Specifically, the present invention is related to a device for encapsulating an electronic monitoring device in a protective housing while allowing the pressure sensor of the monitoring device to remain in fluid communication with the surrounding atmosphere so that it may function.  
           [0004]    2. Background Information  
           [0005]    It is often desired in the art to monitor the conditions of a tire while it is installed and in use on a vehicle. Typical desirable measurements are tire wear, internal temperature, and internal pressure. These measurements are preferably taken while the tire is in use on a vehicle without having to remove the tire from the vehicle or specially position the tire to take the measurement. Numerous types of monitoring devices are known in the art to perform these measurements. One type of known monitoring device uses a passive integrated circuit embedded within the body of the tire that is activated by a radio frequency transmission that energizes the circuit by inductive magnetic coupling. Other prior art devices used for monitoring tire conditions include self-powered circuits that are positioned external of the tire, such as at the valve stem. Other active, self-powered programmable electronic devices are disclosed in U.S. Pat. Nos. 5,573,610, 5,562,787, and 5,573,611 which are assigned to the assignee of the present application.  
           [0006]    One of the problems in the art with these monitoring devices is that they are relatively fragile when compared to the harsh environment of a pneumatic vehicle tire. The forces experienced by a pneumatic tire are sufficient to break the fragile electronic monitoring device and render it unusable. These forces include rotational forces caused by the rotation of the tire and shock forces caused by the tire impacting articles on the ground. It is thus necessary to provide the monitoring device with some protection from these forces. One manner of protecting the sensitive electronic monitoring device is to encapsulate the device in a relatively rigid material such as a hardened epoxy or plastic. The encapsulating material holds the elements of the electronic monitoring device in position with respect to each other and prevents the electronic monitoring device from tearing apart when subjected to the tire forces.  
           [0007]    A problem with encapsulating the monitoring device is that the monitoring device preferably includes a pressure sensor that must remain in fluid communication with the internal cavity of the tire so that the pressure sensor may sense the internal pressure of the tire. The required fluid communication thus dictates that the entire electronic monitoring device cannot be encapsulated and that a breathing hole must be provided either during encapsulation or formed after encapsulation. Forming the breathing hole after encapsulation is generally not desired given the difficulty of precisely locating the hole, cleaning the pressure sensor, and the expense of the additional step in the encapsulation process. It is thus desired in the art to provide an encapsulation device that allows a monitoring device having a pressure sensor to be encapsulated while maintaining fluid communication between the pressure sensor and the surrounding atmosphere.  
           [0008]    Another problem encountered with encapsulating an electronic monitoring device is that the monitoring device must be entirely encapsulated in preferably a single step. The monitoring device thus must float within the encapsulation chamber so that the encapsulation material may completely surround the encapsulation device. It is thus desired in the art to provide an encapsulation device that holds the monitoring device in a manner so that it may be entirely encapsulated in a single step. This problem is complicated when the user of the device wishes to mount the device to the tire with a threaded connection. In such a connection configuration, a threaded post must extend from the device in a manner that allows the threaded post to be threaded into a corresponding cavity in an attachment patch that is connected to the tire.  
         BRIEF SUMMARY OF THE INVENTION  
         [0009]    In view of the foregoing, it is an objective of the present invention to provide a method and a device for encapsulating an electronic monitoring device or tire tag that is used in a pneumatic tire.  
           [0010]    In one embodiment of the invention, the invention provides a method for encapsulating a monitoring device for a pneumatic tire wherein the monitoring device includes a threaded rod and a pressure sensor. The method includes the steps of: positioning the monitoring device in an encapsulation chamber of an encapsulation device with a portion of the threaded rod extending from the encapsulation chamber; positioning a damming element over the pressure sensor to prevent the pressure sensor from clogging; and filling the encapsulation chamber with encapsulation material to encapsulate the monitoring device to form an encapsulated monitoring device.  
           [0011]    Another embodiment of the invention provides a method for encapsulating a monitoring device for a pneumatic tire wherein the monitoring device includes a threaded rod and a pressure sensor. In this embodiment, the method includes the steps of: positioning the monitoring device in an encapsulation chamber of an encapsulation device with a portion of the threaded rod extending from the encapsulation chamber; engaging the threaded rod against the encapsulation device to suspend the electronic monitoring device within the encapsulation chamber; and filling the encapsulation chamber with encapsulation material to encapsulate the monitoring device to form an encapsulated monitoring device.  
           [0012]    In a further embodiment, the invention provides the combination of an encapsulation device for encapsulating a monitoring device and a monitoring device. In this embodiment, the combination includes: an encapsulation device defining an encapsulation chamber; a monitoring device having a threaded rod and a pressure sensor; and the monitoring device being suspended in the encapsulation chamber through the engagement of the threaded rod with the encapsulation device. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a perspective view of an encapsulated monitoring device that was encapsulated in the device of the present invention.  
         [0014]    [0014]FIG. 2 is a perspective view of the device to encapsulate a substrate containing sensitive electronic components and a pressure sensor pack.  
         [0015]    [0015]FIG. 3 is an exploded perspective view of the encapsulating device of the present invention shown in FIG. 2.  
         [0016]    [0016]FIG. 4 is a sectional view taken along line  4 - 4  of FIG. 2.  
         [0017]    [0017]FIG. 5 is a sectional view taken along line  5 - 5  of FIG. 4.  
         [0018]    [0018]FIG. 6 is an enlarged view of the portion encircled by the circle labeled with FIG. 6 in FIG. 5.  
         [0019]    [0019]FIG. 7 is a view similar to FIG. 5 with the encapsulation chamber filled with an encapsulation material.  
         [0020]    [0020]FIG. 8 is an enlarged view of the portion encircled by the circle labeled with FIG. 8 in FIG. 7.  
         [0021]    [0021]FIG. 9 is a section view taken along line  9 - 9  of FIG. 7.  
         [0022]    [0022]FIG. 10 is a section view similar to FIG. 5 showing a first alternative embodiment of the encapsulation device of the invention.  
         [0023]    [0023]FIG. 11 is a top plan view of the device of FIG. 10.  
         [0024]    [0024]FIG. 12 is a view similar to FIG. 10 with the chamber of the device filled with encapsulation material.  
         [0025]    [0025]FIG. 13 is a side elevation view of the encapsulated monitoring device made in the first alternative embodiment of the invention.  
         [0026]    [0026]FIG. 14 is a section view similar to FIG. 5 showing a second alternative embodiment of the encapsulation device of the invention.  
         [0027]    [0027]FIG. 15 is a top plan view of the device of FIG. 14.  
         [0028]    [0028]FIG. 16 is a view similar to FIG. 14 with the chamber of the device filled with encapsulation material.  
         [0029]    [0029]FIG. 17 is a side elevation view of the encapsulated monitoring device made in the second alternative embodiment of the invention.  
         [0030]    [0030]FIG. 18 is a section view similar to FIG. 5 showing a third alternative embodiment of the encapsulation device of the invention.  
         [0031]    [0031]FIG. 19 is a view similar to FIG. 18 with the chamber of the device filled with encapsulation material.  
         [0032]    [0032]FIG. 20 is a side elevation view of the encapsulated monitoring device made in the third alternative embodiment of the invention.  
         [0033]    [0033]FIG. 21 is a section view of a pneumatic tire with an attachment patch and monitoring device connected to the inner surface of the tire sidewall.  
         [0034]    [0034]FIG. 22 is an enlarged exploded view of the encircled portion of FIG. 21.  
         [0035]    [0035]FIG. 23 is an enlarged view of the encircled portion of FIG. 21.  
         [0036]    [0036]FIG. 24 is a section view similar to FIG. 5 showing a fourth alternative embodiment of the encapsulation device of the invention.  
         [0037]    [0037]FIG. 25 is a view similar to FIG. 24 showing the encapsulation material being added to the encapsulation device.  
         [0038]    [0038]FIG. 26 is a section view similar to FIG. 5 showing a fifth alternative embodiment of the encapsulation device of the invention.  
         [0039]    [0039]FIG. 27 is an exploded view showing the encapsulated monitoring device made from the encapsulation device of FIG. 26 aligned with a patch having an extended threaded rod for securing the encapsulated monitoring device to the patch. 
     
    
       [0040]    Similar numbers refer to similar element throughout the specification.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0041]    An encapsulated monitoring device used to monitor pneumatic tires is depicted in FIG. 1 and is indicated generally by the numeral  2 . Encapsulated monitoring device  2  includes a monitoring device  4  that has been encapsulated in an encapsulation material  6 . Encapsulation material  6  creates a protective housing for monitoring device  4  that prevents monitoring device  4  from breaking when subjected to the forces experienced by a pneumatic tire. Encapsulation material  6  may be an epoxy that is substantially rigid when it cures or a suitable plastic. It is desired in the art for encapsulation material  6  to completely surround monitoring device  4  so that monitoring device  4  is completely protected while in use. A problem occurs with encapsulating the entire monitoring device  4  when monitoring device  4  includes a pressure sensor  8  that must remain in fluid communication with the interior chamber of a pneumatic tire for the pressure sensor to function.  
         [0042]    In accordance with one of the objectives of the present invention, a device for encapsulating monitoring device  4  with encapsulation material  6  is depicted in the drawings and is indicated generally by the numeral  10 . Encapsulating device  10  is adapted to entirely encapsulate monitoring device  4  while allowing pressure sensor  8  of monitoring device  4  to remain in fluid communication with the atmosphere surrounding encapsulated monitoring device  2 . Encapsulating device  10  generally includes an encapsulation body  12  that has an encapsulation chamber  14  disposed in body  12 . Encapsulation chamber  14  is configured to receive monitoring device  4  in a floating arrangement such that device  4  is substantially centered in encapsulation chamber  14  when it is received therein. The embodiment of the invention described here and depicted in the drawings is shown for encapsulating a specific embodiment of monitoring device  4  that has an overall rectangular shape with a cylindrical bulge protruding from one side of the rectangle. It is understood that the concepts of the present invention may be adapted to function with monitoring devices having different configurations and shapes than monitoring device  4  depicted in these drawings. Encapsulating device  10  also includes a damming element  16  that is carried by encapsulation body  12  where it contacts monitoring device  4  at pressure sensor  8  to support monitoring device  4  within encapsulation chamber  14  and to prevent pressure sensor  8  from becoming clogged when encapsulation chamber  14  is filled with encapsulation material  6 . Encapsulating device  10  is used by placing monitoring device  4  in encapsulation chamber  14  in a floating arrangement that allows encapsulation material  6  to surround most of monitoring device  4 . Encapsulation material  6  is then poured into or otherwise introduced into encapsulation chamber  14  to surround monitoring device  4 . Encapsulation material  6  is then permitted to cure or dry to form encapsulated monitoring device  2  depicted in FIG. 1.  
         [0043]    Encapsulation body  12  includes a first body half  20  and a second body half  22  that cooperate to form encapsulation chamber  14  when halves  20  and  22  are connected. Body halves  20  and  22  may be connected by a plurality of connectors  24  such as the bolts depicted in the drawings. Each connector  24  is received in a hole  26  in first body half  20  and a threaded hole  28  in second body half  22 . In the embodiment of the invention depicted in the drawings, three connectors  24  are used to hold body halves  20  and  22  together. In other embodiments of the invention, different numbers of connectors  24  may be used and different types of connectors may hold body halves  20  and  22  together. Each hole  26  includes a shoulder  27  that engages the head  30  of connector  24  to create the clamping force between connector  24  and body halves  20  and  22 .  
         [0044]    In accordance with one of the objectives of the present invention, second body half  22  includes a textured surface  32  that forms a portion of encapsulation chamber  14  when body halves  20  and  22  are connected. In the embodiment of the invention depicted in the drawings, textured surface  32  includes a plurality of dimples  34  that are concave with respect to encapsulation chamber  14 . Each dimple  34  is filled with encapsulation material  6  to form a textured surface on encapsulated monitoring device  2  that improves the ability of encapsulated monitoring device  2  to adhere to surfaces such as the innerliner of a pneumatic tire. Other textured surfaces  32  may also be used instead of dimples  34  that simply provide an exemplary embodiment of the present invention.  
         [0045]    First body half  20  includes a chamber wall  36  that defines another portion of encapsulation chamber  14  when halves  20  and  22  are connected. Chamber wall  36  includes a battery portion  38  that extends into first body half  20  to accommodate the battery  40  of monitoring device  4 .  
         [0046]    Although first and second body halves  20  and  22  may be configured to completely form encapsulation chamber  14  when they are connected, the preferred embodiment of the present invention uses a top plate  42  and a bottom plate  44  to complete encapsulation chamber  14  and to hold body halves  20  and  22  together. Body halves  20  and  22  are sandwiched between top plate  42  and bottom plate  44 . A plurality of connectors  46  connect elements  42 ,  20 ,  22 , and  44  in a manner that is known in the art. For instance, each connector  46  may include a bolt  48  that is configured to extend entirely through top plate  42 , a body half  20  or  22 , and bottom plate  44  where a nut  50  threadably engages the threaded end of bolt  48 . A washer  52  may further be used between nut  50  and bottom plate  44 . In other embodiments of the present invention, the bore  54  and bottom plate  44  may be threaded to threadably receive bolt  48 .  
         [0047]    In accordance with another objective of the present invention, top plate  42  has an opening  60  that substantially matches the contours of encapsulation chamber  14 . Opening  60  forms an edge  62  in top plate  42 . As best seen in FIG. 9, edge  62  is substantially flush with encapsulation wall  36  and battery portion  38  while extending over a portion of encapsulation chamber  14  to form a lip  64 . Lip  64  serves an indicator that tells a person filling encapsulation chamber  14  with encapsulation material  6  that encapsulation chamber  14  is completely filled. The person filling encapsulation chamber  14  thus stops adding encapsulation material  6  to encapsulation chamber  14  when material  6  reaches lip  64 . In automated applications, a sensor may be disposed at lip  64  to indicate when encapsulation chamber  14  has been filled. In the exemplary embodiment of the present invention, lip  64  extends only along one side of encapsulation chamber  14 . It is also contemplated that lip  64  may extend entirely about encapsulation chamber  14  or merely over another small portion of encapsulation chamber  14  different from the bottom edge depicted in the drawings.  
         [0048]    In accordance with another objective of the present invention, body halves  20  and  22  cooperate to hold monitoring device  4  in a floating disposition within encapsulation chamber  14 . The floating disposition allows monitoring device  4  to be entirely surrounded by encapsulation material  6 . One of the manners of supporting monitoring device  4  in this floating disposition is to support the antenna  70  of monitoring device  4  in a channel  72  disposed in body  12 . In the preferred embodiment of the present invention, channel  72  is formed in one or both of mating surfaces  74  of body halves  20  and  22  so that monitoring device  4  may be placed in encapsulation chamber  14  as body halves  20  and  22  are being put together to clamp antenna  70  between body halves  20  and  22 . In the preferred embodiment, channel  72  is partially formed in each body half  20  and  22 . Channel  72  includes a wide area  76  adjacent encapsulation chamber  14  that allows encapsulation material  6  to surround a portion of antenna  70  to provide strength to antenna  70  to help prevent it from breaking off.  
         [0049]    Surfaces  32  and  36  are configured to be spaced from each element of monitoring device  4  when antenna  70  is received in channel  72  formed when halves  20  and  22  are connected. As may be seen in FIGS. 4 and 5, a generous space between each surface of body  12  and monitoring device  4  is provided when monitoring device  4  is held in the floating disposition by the clamping of antenna  70 . In accordance with another objective of the present invention, damming element  16  also helps hold the floating disposition of monitoring device  4  by supporting the end of monitoring device  4  opposite antenna  70 .  
         [0050]    Damming element  16  is adjustably carried by body  12  so that the position of damming element  16  may be quickly and easily adjusted with respect to monitoring device  4  and specifically pressure sensor  8 . In the preferred embodiment of the present invention, damming element  16  is threaded and is threadably received in a threaded bore formed in body half  20 . The threaded connection between damming element  16  by body half  20  allows the position of damming element  16  to be adjusted with respect to pressure sensor  8  by rotating damming element  16  with respect to body element  20 .  
         [0051]    Damming element  16  preferably is in the form of a cylinder having an outer surface  80  that snugly fits within bore  78  of first body half  20 . First body half  20  includes an outer O-ring seat  82  that seats an outer O-ring  84  in a manner that forces outer O-ring  84  between outer surface  80  and first body half  20 . Outer O-ring  84  thus seals encapsulation chamber  14  from bore  78 .  
         [0052]    In accordance with another objective of the present invention, damming element  16  is used to prevent pressure sensor  8  from becoming clogged with encapsulation material  6  when encapsulation chamber  14  is filled with encapsulation material  6 . As such, damming element  16  is configured to engage pressure sensor  8  and surround the inlet  86  of pressure sensor  8  that must remain in fluid communication with the surrounding atmosphere to provide a measurement of the pressure of the surrounding atmosphere. Damming element  16  includes an inner O-ring seat  88  disposed radially inward of outer surface  80  to form a blocking wall  90  between inner O-ring seat and outer wall  80  of damming element  16 . An inner O-ring  92  is disposed in inner O-ring seat  88  to form a seal between damming element  16  and pressure sensor  8 . Inner O-ring  92  thus seals inlet  86  from encapsulation chamber  14 .  
         [0053]    Another objective of the present invention involves further sealing inlet  86  from encapsulation chamber  14  by providing a breathing tube  94  that is disposed in a longitudinal passageway  96  in the center of damming element  16 . Breathing tube  94  snugly fits over inlet  86  to further seal inlet  86  from encapsulation chamber  14 . Inner O-ring  92  is sandwiched between breathing tube  94 , pressure sensor  8 , and damming element  16  to form a tight seal between breathing tube  94  and encapsulation chamber  14  that prevents encapsulation material  6  from coming into contact with inlet  86 . Breathing tube  94  may extend entirely out of longitudinal passageway  96  or may stop short of the end of damming element  16 . In other embodiments of the present invention, breathing tube  94  may only have a hollow portion at its tip where it fits over inlet  86  of pressure sensor  8 . The remaining portion of breathing tube  94  may be solid.  
         [0054]    Encapsulating device  10  is used by first clamping monitoring device  4  between body halves  20  and  22  by clamping antenna  70  in channel  72 . Connectors  24  are inserted to hold body halves  20  and  22  together. Breathing tube  94  and damming element  16  may then be inserted into body half  20  and adjusted to contact pressure sensor  8  such that inlet  86  of pressure sensor  8  is sealed from encapsulation chamber  14 . Once damming element  16  is properly adjusted and connected to pressure sensor  8 , monitoring device  4  is held in a floating disposition within encapsulation chamber  14 . Top plate  42  and bottom plate  44  may then be connected to the remaining elements to close the bottom of encapsulation chamber  14  and provide lip  64 . After body  12  has been assembled, encapsulation material  6  may be poured into encapsulation chamber  14  through opening  60  in top plate  42 . The insertion of encapsulation material  6  is stopped when it reaches the level of lip  64 . Encapsulation material  6  is allowed to set up or cure before disassembling body  12  and removing encapsulated monitoring device  2  from encapsulating device  10 . Damming element  16  ensures that pressure sensor  8  remains in fluid communication with the surrounding atmosphere once monitoring device  4  has been encapsulated as depicted in FIG. 1.  
         [0055]    A first alternative embodiment of a device for encapsulating a monitoring device  104  with an encapsulation material  106  is indicated generally by the numeral  100  in FIGS.  10 - 13 . Encapsulating device  100  is adapted to entirely encapsulate monitoring device  104  while allowing pressure sensor  108  of monitoring device  104  to remain in fluid communication with the atmosphere surrounding encapsulated monitoring device  102 . Encapsulating device  100  generally includes an encapsulation body  112  that has an encapsulation chamber  114  disposed in body  112 . Encapsulation chamber  114  is configured to receive monitoring device  104  in a floating arrangement such that device  104  is substantially centered in encapsulation chamber  114  when it is received therein. The embodiment of the invention described here and depicted in the drawings is shown for encapsulating a specific embodiment of monitoring device  104  that has an overall rectangular shape. It is understood that the concepts of the present invention may be adapted to function with monitoring devices having different configurations and shapes than monitoring device  104  depicted in these drawings. Encapsulating device  100  also includes a damming element  116  that is carried by encapsulation body  112  where it contacts monitoring device  104  at pressure sensor  108  to support monitoring device  104  within encapsulation chamber  1   14  and to prevent pressure sensor  108  from becoming clogged when encapsulation chamber  114  is filled with encapsulation material  106 . One example of a damming element is described above. Encapsulating device  100  is used by placing monitoring device  104  in encapsulation chamber  114  in a floating or suspended arrangement that allows encapsulation material  106  to surround most of monitoring device  104 . Encapsulation material  106  is then poured into or otherwise introduced into encapsulation chamber  114  to surround monitoring device  104 . Encapsulation material  106  is then permitted to cure or dry to form encapsulated monitoring device  102  depicted in FIG. 13.  
         [0056]    Encapsulation body  112  includes a first body half  120  and a second body half  122  that cooperate to form encapsulation chamber  114  when halves  120  and  122  are connected. Body halves  120  and  122  may be connected by a plurality of connectors such as the bolts depicted with the above-described embodiment of the invention. First  120  or second  122  body half may include a textured surface that forms a portion of encapsulation chamber  114  when body halves  120  and  122  are connected.  
         [0057]    Body halves  120  and  122  cooperate to hold monitoring device  104  in a floating disposition within encapsulation chamber  114 . The floating disposition allows monitoring device  104  to be entirely surrounded by encapsulation material  106 . One of the manners of supporting monitoring device  104  in this floating disposition is to support the antenna  170  of monitoring device  104  in a channel  172  defined by body  112 . In the preferred embodiment of the present invention, channel  172  is formed in one or both of the mating surfaces of body halves  120  and  122  so that monitoring device  104  may be placed in encapsulation chamber  114  as body halves  120  and  122  are being put together to clamp antenna  170  between body halves  120  and  122 . In the preferred embodiment, channel  172  is partially formed in each body half  120  and  122 . Channel  172  includes a wide area  176  adjacent encapsulation chamber  114  that allows encapsulation material  106  to surround a portion of antenna  170  to provide strength to antenna  170  to help prevent it from breaking off.  
         [0058]    The inner surfaces of the body halves are configured to be spaced from each element of monitoring device  104  when antenna  170  is received in channel  172  formed when halves  120  and  122  are connected. As may be seen in FIGS. 10 and 12, a generous space between each surface of body  112  and monitoring device  104  is provided when monitoring device  104  is held in the floating disposition by the clamping of antenna  170 . Damming element  116  also helps hold the floating disposition of monitoring device  104  by supporting the end of monitoring device  104  opposite antenna  170 .  
         [0059]    In the first alternative embodiment of the invention, monitoring device  104  includes a threaded rod  180  that is used to mount encapsulated monitoring device  102  to an attachment patch  182  such as the one shown in FIGS.  21 - 23 . Encapsulation device  100  is designed with an opening  184  that allows a portion of threaded rod  180  to extend from encapsulation chamber  114 . Body  112  of encapsulation device  100  defines a recess  186  disposed adjacent threaded rod  180 . Recess  186  may extend entirely about rod  180  when monitoring device  104  is suspended within encapsulation chamber  114 . Recess  186  is configured to form a raised boss  188  at the area where threaded rod  180  extends from the main body of encapsulated monitoring device  102 . Boss  188  is used to engage a gasket  190  (FIGS. 22 and 23) that is disposed adjacent a threaded cavity  192  defined by attachment patch  182 . As shown in FIGS. 22 and 23, threaded cavity  192  may be defined by an insert that is securely held by the body of patch  182 . Gasket  190  is raised with respect to the outer surface of patch  182  so that boss  188 , or the outer surface  194  of encapsulated monitoring device  102  engages and compresses gasket  190  as shown in FIG. 23. This compression creates a locking force between the threads of rod  180  and cavity  192 . The locking force helps prevent encapsulated monitoring device  102  from vibrating loose when used in a pneumatic tire  196 .  
         [0060]    A second alternative embodiment of a device for encapsulating a monitoring device  204  with an encapsulation material  206  is indicated generally by the numeral  200  in FIGS.  14 - 17 . Encapsulating device  200  is adapted to entirely encapsulate monitoring device  204  while allowing pressure sensor  208  of monitoring device  204  to remain in fluid communication with the atmosphere surrounding encapsulated monitoring device  202 . Encapsulating device  200  generally includes an encapsulation body  212  that has an encapsulation chamber  214  disposed in body  212 . Encapsulation chamber  214  is configured to receive monitoring device  204  in a floating or suspended arrangement such that device  204  is substantially centered in encapsulation chamber  214  when it is received therein. The embodiment of the invention described here and depicted in the drawings is shown for encapsulating a specific embodiment of monitoring device  204  that has an overall rectangular shape. It is understood that the concepts of the present invention may be adapted to function with monitoring devices having different configurations and shapes than monitoring device  204  depicted in these drawings. Encapsulating device  200  also includes a damming element  216  that is carried by encapsulation body  212  where it contacts monitoring device  204  at pressure sensor  208  to support monitoring device  204  within encapsulation chamber  214  and to prevent pressure sensor  208  from becoming clogged when encapsulation chamber  214  is filled with encapsulation material  206 . Encapsulating device  200  is used by placing monitoring device  204  in encapsulation chamber  214  in a floating arrangement that allows encapsulation material  206  to surround most of monitoring device  204 . Encapsulation material  206  is then poured into or otherwise introduced into encapsulation chamber  214  to surround monitoring device  204 . Encapsulation material  206  is then permitted to cure or dry to form encapsulated monitoring device  202  depicted in FIG. 17.  
         [0061]    Encapsulation body  212  includes a first body half  220  and a second body half  222  that cooperate to form encapsulation chamber  214  when halves  220  and  222  are connected. Body halves  220  and  222  may be connected by a plurality of connectors such as the bolts depicted with the above-described embodiment of the invention. First  220  or second  222  body half may include a textured surface that forms a portion of encapsulation chamber  214  when body halves  220  and  222  are connected.  
         [0062]    In the second alternative embodiment of the invention, the antenna of monitoring device  204  is not used to suspend monitoring device  204  within chamber  214 . In this embodiment, the threaded rod  280  that extends from chamber  214  is used to position and suspend monitoring device  204 . Device  200  cooperates with threaded rod  280  by providing an opening  282  that has a width slightly larger than the outer diameter of threaded rod  280 . This configuration allows rod  280  to rest against body  212  to suspend monitoring device  204 . The length of opening  282  is somewhat larger than the diameter of rod  280  so that the encapsulation material  206  may be introduced into cavity  214 . In this embodiment of the invention, recess  186  is also provided to form boss  188  as described above.  
         [0063]    A third alternative embodiment of a device for encapsulating a monitoring device  304  with an encapsulation material  306  is indicated generally by the numeral  300  in FIGS.  18 - 20 . Encapsulating device  300  is adapted to entirely encapsulate monitoring device  304  while allowing pressure sensor  308  of monitoring device  304  to remain in fluid communication with the atmosphere surrounding encapsulated monitoring device  302 . Encapsulating device  300  generally includes an encapsulation body  312  that has an encapsulation chamber  314  disposed in body  312 . Encapsulation chamber  314  is configured to receive monitoring device  304  in a floating arrangement such that device  304  is substantially centered in encapsulation chamber  314  when it is received therein. The embodiment of the invention described here and depicted in the drawings is shown for encapsulating a specific embodiment of monitoring device  304  that has an overall rectangular shape. It is understood that the concepts of the present invention may be adapted to function with monitoring devices having different configurations and shapes than monitoring device  304  depicted in these drawings. Encapsulating device  300  also includes a damming element  316  that is carried by encapsulation body  312  where it contacts monitoring device  304  at pressure sensor  308  to support monitoring device  304  within encapsulation chamber  314  and to prevent pressure sensor  308  from becoming clogged when encapsulation chamber  314  is filled with encapsulation material  306 . Encapsulating device  300  is used by placing monitoring device  304  in encapsulation chamber  314  in a floating arrangement that allows encapsulation material  306  to surround most of monitoring device  304 . Encapsulation material  306  is then poured into or otherwise introduced into encapsulation chamber  314  to surround monitoring device  304 . Encapsulation material  306  is then permitted to cure or dry to form encapsulated monitoring device  302  depicted in FIG. 20.  
         [0064]    Encapsulation body  312  includes a first body half  320  and a second body half  322  that cooperate to form encapsulation chamber  314  when halves  320  and  322  are connected. Body halves  320  and  322  may be connected by a plurality of connectors such as the bolts depicted with the above-described embodiment of the invention. First  320  or second  322  body half may include a textured surface that forms a portion of encapsulation chamber  314  when body halves  320  and  322  are connected.  
         [0065]    The antenna of monitoring device  304  is disposed internal to encapsulated monitoring device  302 . A threaded rod  380  extends from encapsulation chamber  314  in a manner similar to those described above. In this embodiment of the invention, rod  380  supports monitoring device  304  in the suspended condition within chamber  314 . The third alternative embodiment of the invention may also use boss  188  as described above.  
         [0066]    A fourth alternative embodiment of a device for encapsulating a monitoring device  404  with an encapsulation material  406  is indicated generally by the numeral  400  in FIGS. 24 and 25. Encapsulating device  400  is adapted to entirely encapsulate monitoring device  404  while allowing pressure sensor  408  of monitoring device  404  to remain in fluid communication with the atmosphere surrounding the encapsulated monitoring device. Encapsulating device  400  generally includes an encapsulating body  412  that has an encapsulation chamber  414  defined by body  412 . Encapsulation chamber  414  is configured to receive monitoring device  404  in a floating or suspended arrangement such that device  404  is substantially centered within encapsulation chamber  414  when it is received therein. Encapsulation device  400  further includes a damming element  416  that is carried by encapsulation body  412  where it contacts monitoring device  404  at pressure sensor  408  to support monitoring device  404  within encapsulation chamber  414  to prevent pressure sensor  408  from becoming clogged when encapsulation chamber  414  is filled with encapsulation material  406 .  
         [0067]    Encapsulation body  412  includes a first body half  420  and a second body half  422  that cooperate to define encapsulation chamber  414  when halves  420  and  422  are connected. Body halves  420  and  422  may be connected by a plurality of connectors such as the bolts depicted with the above-described embodiment of the invention or other suitable mechanisms for applying pressure as shown in FIG. 25 and indicated by the numeral  423 . Mechanisms  423  hold halves  420  and  422  together while chamber  414  is being filled with encapsulation material  406 .  
         [0068]    In the embodiment of monitoring device  404  depicted in FIGS. 24 and 25, the antenna is disposed internal to monitoring device  404 . As described above, a threaded rod  480  extends from encapsulation chamber  414  through body  412 . A gasket  481  is used to seal chamber  414  around rod  480 . Body  412  may also define a recess that is used to form boss  188  as described above. Threaded rod  480  may be used to suspend monitoring device  404  within chamber  414 .  
         [0069]    Body  412  defines a fill inlet  430  and a vent  432  that are used to introduce encapsulation material  406  into chamber  414  and to vent air from chamber  414  as encapsulation material  406  is introduced into chamber  414 . This process is depicted in FIG. 25 wherein a supply of encapsulation material  434  is connected to fill opening  430  and pressurized encapsulation material  406  is introduced into chamber  414 . A venting device  436  may optionally be used to draw air from chamber  414  and to pull encapsulation material  406  through the entire volume of chamber  414 . Devices  434  and  436  are removed and leave straws of encapsulation material  406  in openings  430  and  432  after encapsulation material  406  is cured. These straws may be removed from the encapsulated monitoring device by known methods.  
         [0070]    A fifth alternative embodiment of a device for encapsulating a monitoring device  504  with an encapsulation material  506  is indicated generally by the numeral  500  in FIG. 26. Encapsulating device  500  is adapted to entirely encapsulate monitoring device  504  while allowing the pressure sensor  508  of monitoring device  504  to remain in fluid communication with the atmosphere surrounding the encapsulated monitoring device  502 . Encapsulating device  500  generally includes an encapsulation body  512  that defines an encapsulation chamber  514 . Encapsulation chamber  514  is configured to receive monitoring device  504  in a suspended or floating arrangement. Encapsulating device  500  also includes a damming element  516  that prevents pressure sensor  508  from becoming clogged.  
         [0071]    Encapsulation body  512  includes a first body half  520  and a second body half  522  that cooperate to form encapsulation chamber  514  when halves  520  and  522  are connected. As described above, body  512  may also define a fill opening  530  and a vent opening  532  that are used to fill chamber  514  with encapsulation material  506 .  
         [0072]    In the fifth alternative embodiment of the invention, encapsulated monitoring device  502  includes a threaded sleeve  540  that is adapted to engage a threaded post  542  that extends from an attachment patch  544 . Threaded sleeve  540  is shown in FIG. 26 as being attached to body half  520  with a gasket  546 . An appropriate connector  548  may secure sleeve  540  to monitoring device  504 . In this situation, threaded sleeve  540  helps suspend monitoring device  504  within chamber  514 . In another embodiment, threaded sleeve  540  is spaced from monitoring device  504  and encapsulation material  506  holds sleeve  540  to monitoring device  504  after encapsulation material  506  cures. Body half  520  may be configured to define a recess  550  disposed about the opening to threaded sleeve  540 . Recess  550  is adapted to cooperate with a boss  552  that projects from patch  544  about threaded post  542 . Boss  542  and recess  550  are adapted to form a locking arrangement when encapsulated monitoring device  502  is threaded onto patch  544  as described above.  
         [0073]    In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed.  
         [0074]    Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described.