Abstract:
A monitoring device and patch assembly includes a patch that removably and re-attachably holds the monitoring device. The patch is adapted to connect the monitoring device to a pneumatic tire when the monitoring device is held by the patch. The patch is configured to hold a monitoring device having a rounded outer surface. The patch holds the rounded monitoring device by having a resilient tube with an outlet having a diameter smaller than the diameter of the monitoring device. The monitoring device of the invention includes a feature that allows it to be removed from the patch.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation-in-part application application claiming priority from U.S. patent application Ser. No. 09/976,076 filed Oct. 12, 2001 which is a divisional of U.S. Pat. No. 6,386,251 issued May 14, 2002, which is a continuation application claiming priority from U.S. Pat. No. 6,030,478 issued Feb. 29, 2000; the disclosures of each are incorporated herein by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Technical Field  
           [0003]    The invention generally relates to mounting arrangements for electronic monitoring devices and, more particularly, to an electronic monitoring device and patch assembly wherein the electronic monitoring device is removably attached to the patch so that the electronic monitoring device may be repeatedly removed from and reattached to the patch. Specifically, the present invention relates to a patch that removably and re-attachably holds an electronic monitoring device having a rounded body.  
           [0004]    2. Background Information  
           [0005]    Monitoring the engineering conditions of tires is becoming more and more desirable in the art. The monitored engineering conditions include internal pressure and internal temperature and other conditions that are useful for improving tire efficiency in the field. Monitoring tire conditions on large off-the-road equipment has become especially desirable given the costs of the tires.  
           [0006]    Prior art methods of monitoring large truck tires have included passive integrated circuits embedded in the body of the tire, or self-powered circuits which are positioned external to the tire. The passive integrated circuits rely on inductive magnetic coupling or capacitative coupling to energize the circuit, thus providing power to the circuit from a source remote from the tire. Self-powered circuits positioned external to the tire are exposed to damage from the environment such as weather, road hazards and even vandalism.  
           [0007]    Recent engineering advances have permitted the installation of monitoring devices having active integrated circuits within tires. One such device is described in U.S. Pat. No. 5,562,787 to Koch et al. entitled Method of Monitoring Conditions of Vehicle Tires, incorporated herein by reference, and assigned to the assignee of the present invention. These devices include an active circuit powered by a dedicated long life, miniature battery and at least one sensor for detecting, optionally storing and transmitting real time engineering conditions within the tire. Such devices are capable of being programmed to remain in an active, but dormant condition, but will switch automatically to an “awakened” condition in response to an external signal or a condition which exceeds preset limits.  
           [0008]    These devices have been mounted to the tires in some prior art situations. Other systems have placed the monitoring device loosely inside the tire so that the monitoring device could roll freely within the tire while performing its monitoring functions. An example of this type of device is explained in U.S. Pat. No. 6,082,192. Although these “loose” devices have been accepted for use in some tires and in some situations, other tires and other situations are believed to perform better when the monitoring device is fixed to the tire. In these situations, a mount is desired that can be used to mount a “loose” monitoring device—such as the monitoring device having the rounded body of U.S. Pat. No. 6,082,192—into a tire.  
         BRIEF SUMMARY OF THE INVENTION  
         [0009]    The invention provides a monitoring device and patch assembly wherein the patch is configured to removably and re-attachably hold a monitoring device having a body that is outwardly curved. In one embodiment of the invention, the patch includes a tube that removably and re-attachably receives the monitoring device.  
           [0010]    The invention also provides a monitoring device that has a feature that allows the monitoring device to be removed from the patch. In one embodiment, the feature is an opening in the body of the monitoring device that allows a hook to be connected to the body to extract the monitoring device from the patch.  
           [0011]    The invention also provides a monitoring device and patch combination that positions the monitoring device in a predictable orientation with respect to the tire so that the antenna of the monitoring device may be tuned for the orientation. The invention provides embodiments wherein the antenna is encapsulated and freely extending.  
           [0012]    The invention also provides an embodiment having a teardrop shaped monitoring device that is attached to a patch. The antenna of the monitoring device may extend into the tail portion of the teardrop. The teardrop shaped monitoring device may also be removably and re-attachably connected to the patch. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is an exploded cross-sectional view of the first embodiment of the patch of the invention showing the housing and cavity for the tag assembly.  
         [0014]    [0014]FIG. 2 is a cross-sectional view of the patch of the present invention attached to the innerliner of a tire.  
         [0015]    [0015]FIG. 3 is a cross-sectional view of the electronic monitoring device embedded in potting material.  
         [0016]    [0016]FIG. 4 is a cross-sectional view of the mold used to embed the electronic monitoring device in the potting material.  
         [0017]    [0017]FIG. 5 is a cross-sectional view showing a battery attached to the tag; forming a tag assembly.  
         [0018]    [0018]FIG. 6 is a cross-sectional view of the tag assembly assembled inside the cavity of the tire patch, with a locking device holding the tag assembly in place, before crimping of the locking device.  
         [0019]    [0019]FIG. 7 is a second embodiment of the present invention depicting a cross-sectional view of the tag assembly being locked inside the cavity of the tire patch with a threaded insert.  
         [0020]    [0020]FIG. 8 is a third embodiment of the present invention showing a threaded tag assembly threaded into the cavity of the rubber patch housing.  
         [0021]    [0021]FIG. 9 is a fourth embodiment of the present invention, shown in perspective, showing a slot and tab arrangement for locking a tag assembly to a rubber patch housing.  
         [0022]    [0022]FIG. 10 is a top plan view of the fifth embodiment of the invention showing a tag assembly connected to a patch.  
         [0023]    [0023]FIG. 11 is a section view of the patch taken along line  11 - 11  of FIG. 10 showing the patch in section with the tag assembly in elevation.  
         [0024]    [0024]FIG. 12 is a view similar to FIG. 11 showing the tag assembly being removed from the patch.  
         [0025]    [0025]FIG. 13 is a view similar to FIG. 11 showing the tag assembly and patch immediately after the tag assembly has been removed from the patch.  
         [0026]    [0026]FIG. 14 is a top plan view of the sixth embodiment of the invention showing a tag assembly connected to a patch.  
         [0027]    [0027]FIG. 15 is a section view of the patch taken along line  15 - 15  of FIG. 14 showing the patch in section with the tag assembly in elevation.  
         [0028]    [0028]FIG. 16 is a section view of a pneumatic tire with a seventh embodiment of the invention mounted to the crown portion of the tire.  
         [0029]    [0029]FIG. 17 is a section view taken through the patch and monitoring device of FIG. 16.  
         [0030]    [0030]FIG. 18 is a section view similar to FIG. 17 showing an eighth embodiment of the invention wherein the entire length of the antenna is not encapsulated.  
         [0031]    [0031]FIG. 19 is a section view similar to FIG. 17 showing a ninth embodiment of the invention wherein the encapsulated monitoring device is threaded to the patch.  
         [0032]    [0032]FIG. 20 is a section view showing a tenth embodiment of the invention wherein an encapsulated monitoring device is threaded into a housing that is encapsulated around a portion of the patch.  
         [0033]    Similar numbers refer to similar parts throughout the specification. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0034]    Embodiments of the present invention will be described below with reference to the drawings.  
         [0035]    [0035]FIG. 1 shows a rubber patch  10  of the present invention. The patch  10  has a first side  12  which includes a housing  14  with a cavity  16  of a preselected configuration. As shown in FIG. 1, the housing  14  has a cavity  16  which is cylindrical, although the cavity  16  may be of any convenient configuration, as will become apparent from the description which follows. The patch has a second opposite side  18  approximating the contour of an innerliner of a tire (not shown). In a preferred embodiment, the rubber patch is vulcanized and then assembled to the vulcanized tire. Although any method for assembling the vulcanized rubber patch to the vulcanized tire, one acceptable and preferred method is set forth in U.S. Pat. No. 5,971,046; the disclosures of which are incorporated herein by reference. In accordance with the referenced application, the patch may be a rubber selected from the group consisting of Ethylene Propylene Diene Monomer (EPDM) rubber, butyl rubber, natural rubber, neoprene and mixtures thereof. One preferred embodiment is a mixture of chlorobutyl rubber and natural rubber. Another preferred embodiment is a mixture of Styrene-Butadiene rubber (SBR) and natural rubber. Typically, patches made of these rubber compositions may be cured by heating to a temperature of about 150° C. and holding at this temperature for about 30 minutes. The time and temperature may be modified as necessary to achieve sufficient curing of the patch for further assembly. The second side  18  of the patch  10  approximates the contour of an innerliner of a tire. The contour of the second side  18  preferably is radiused to have about the same radius as the tire to which it is assembled, the radius being larger for larger tires. For very large tires, such as for off-the-road tires, the radius may be eliminated altogether, so that there is no contour and the opposite side is flat, having no contour.  
         [0036]    Affixed to the second side  18  of the vulcanized tire patch is a dual cure bonding layer  20 , which has a first side (not shown) and a second side  22 . This dual cure bonding layer may be assembled to the patch at any time following vulcanization of the patch and prior to assembly of the patch assembly to the tire innerliner. The dual cure bonding layer is permanently assembled to the patch to form patch assembly  60 . A non-curing cement (not shown) is applied to side  18  of the patch in order to hold the dual cure bonding layer  20  onto the patch. Exemplary non-curing cement and an exemplary dual cure bonding layer are products of Patch Rubber Company. The important feature of the dual cure bonding layer is that it can be chemically activated and cured, without the need for heating to an elevated temperature. The process is diffusion controlled, however, and some minimal heating will speed the curing process. The dual cure bonding layer may be any material which can be activated and cured to the vulcanized rubber of the tire innerliner and the vulcanized patch. Preferably, however, the dual cure bonding rubber is natural rubber. The dual cure bonding rubber, after application of the activating cement, may cure at room temperature over a period of seventy-two (72) hours. However, if more rapid curing is desired, this may be accomplished by heating to 45° C. for at least twenty-four hours.  
         [0037]    Referring now to FIG. 2, patch assembly  60  is then assembled to the innerliner  75  of tire  71 . Activating cement is first applied to second side  22  of dual cure bonding layer  20 . The patch assembly is then stitched to the innerliner of the vulcanized tire and the patch assembly/tire assembly is allowed to cure for a sufficient time and temperature to form a strong bond between the tire and the patch assembly. The times and temperatures utilized for this curing may be basically the same times and temperatures as previously discussed. To ensure a strong bond, the patch assembly optionally may be clamped to the tire innerliner  75 , until the curing cycle is completed.  
         [0038]    The electronic monitoring device is a circuit board which includes sensors and may include an antenna. The electronic monitoring device may include a power source or battery, although the battery may be attached to the electronic monitoring device at a later time. In the preferred embodiment, the battery is not included as part of the electronic monitoring device. The electronic monitoring device  34  is encapsulated in a potting material  40  which solidifies into a rigid material as shown in FIG. 3. Referring to FIGS. 3 and 4, the electronic monitoring device  34  is placed within a mold  42  having a first half  52  and a second half  54 . The mold is then filled with the potting material  40  in fluid form, which fills the mold and flows around the electronic monitoring device and allowed to cure, resulting in a rigid tag. Any potting material having a Young&#39;s Modulus of at least 30,000 psi and which is capable of being molded around the electronic monitoring device without damaging any of the components of the device. Preferably, the potting material has a Young&#39;s Modulus of at least about 100,000 psi. Two preferred potting materials include epoxy and urethane. If desired, the curing of the potting material around the electronic device may be accelerated by preheating the mold to an elevated temperature which is above ambient, but below the temperature at which damage to the electronic monitoring device will occur. A preferred temperature is about 80° C. After the epoxy has been cured, the mold halves  52 ,  54  are separated, yielding a rigid, encapsulated tag  30 . In a preferred embodiment, FIG. 5, a battery  68  which provides power to the tag  30  is attached to the tag to form a tag assembly  70 . Although the battery is shown as held in position contacting the electronic monitoring device  34  by threading, any suitable means of attaching the battery to the circuit board so that the battery may be removed is acceptable. Alternate means of attaching the battery to the circuit board may include spring clips, lock pins or other hold down devices.  
         [0039]    The tag assembly  70  may be of any configuration which allows it to fit within the contour of the cavity  16 , both of which are cylindrical in the embodiment shown in FIG. 1. In the preferred embodiment, tag assembly  70  is assembled into the cavity  16  as shown in FIG. 6. Since the rubber patch assembly can be attached to the tire using an air cure or low temperature cure, it is understood that the sequence of assembling the tag assembly into the rubber patch housing may be accomplished either before or after the rubber patch is attached to the tire innerliner. Tag assembly includes an optional antenna  72 . Housing  14  includes slots  74  to receive the antenna. After the tag assembly  70  is in place within the cavity, at least one lock pin  76  is inserted through a first aperture  78  in housing  80 . As shown in FIG. 6, lock pin  76  is positioned across at least a portion of the top of tag assembly  70 , preferably through a second aperture  82  on the opposite side of the housing. Alternatively, lock pin  76  could extend into the potting of tag assembly  70 .  
         [0040]    The positioning of the lock pin is not critical, so long as lock pin  78  positively secures tag assembly  70  into position within cavity  16  and prevents tag assembly  70  from moving. After insertion through the housing  14 , the lock pin  76  is deformed so that it will not back out of the apertures. Tag assembly  70  may then be removed from the housing by simply drilling lock pin  76  out of aperture  78 .  
         [0041]    Many different methods of positively locking the tag assembly can be accomplished. By way of illustration of equivalent locking techniques, instead of a locking pin, a self-tapping screw may be inserted through aperture  78  and screwed into position within the potting.  
         [0042]    In a second embodiment of the present invention, illustrated in FIG. 7, tag assembly  70  has a profile corresponding to that of cavity  16 . Tag assembly is assembled into the bottom of cavity  16 . Housing  14  extends above tag assembly  70  after it has been assembled into cavity  16 . Insert  90 , also having a profile corresponding to cavity  16  is the inserted into the housing until the bottom  96  of insert  90  contacts the top of tag assembly  70 , thus securing it in place. Insert  90  is then locked in place. This may be accomplished by any convenient method, such as by extending a locking pin through insert  90  and deforming it, or by utilizing locking tabs to secure insert  90  to patch assembly  10 . However, in the preferred embodiment shown in FIG. 7, insert  90  includes external threads  94  which correspond to internal threads  92  formed in housing  14 . Insert  90  is screwed into housing  14  until the insert bottom  96  contacts the top of tag assembly  70 . Of course, regardless of the method used to secure tag assembly  70  in place in cavity  16 , tag assembly is readily removable for battery replacement or replacement of the entire assembly  70  by removing insert  90  from housing  14 . It is obvious that tag assembly  70  may be reinserted after accomplishing repair or replacement, or after retreading of the tire by simply replacing insert  90  over the reassembled tag assembly and locking insert  90  in place as discussed above.  
         [0043]    In a third embodiment of the present invention, FIG. 8, a tag assembly of  110  including the components previously discussed, is formed with external threads  112  in the potting. Rubber patch assembly  120 , also similar to rubber patches previously discussed, includes internal threads  122  formed in housing  124  which mate with the external: threads  112  of tag assembly. Tag assembly  110  is assembled into rubber patch assembly  120  by simply screwing tag assembly  110  into housing  124 . While this arrangement normally should be sufficient to lock tag assembly to rubber patch assembly, an optional locking pin or set screw may be added to the assembly to lock the internal and external threads in place and prevent tag assembly from backing out of the housing of rubber patch assembly  120 .  
         [0044]    From the foregoing, other embodiments should be obvious. For example, a slot and spline arrangement not shown may be used to lock the tag assembly into the housing. Mating slots and splines are formed in the potting of the tag assembly and in the housing. After placing the tag assembly into the housing, an optional locking device as previously discussed may be used to prevent the tag assembly from backing out of the housing.  
         [0045]    In yet another embodiment, depicted in FIG. 9, tag assembly  130  is formed with at least one tab  132 , while housing  142  of rubber patch  140  is formed with slots  144  corresponding to tabs on tag assembly  130 . At the bottom of the slots is a ring  146  having an internal diameter corresponding to the slot depth on the housing and extending from each slot at least partially around the housing bottom. Once tabs  132  of tag assembly  130  are mated with slots  144  of rubber patch and tag assembly  130  is inserted into housing  142 , tag assembly  130  is rotated sufficiently so that tabs  132  are rotated into ring  146  and no longer are aligned with slots  144 , locking the tag assembly to rubber patch  140 . An optional locking mechanism, such as discussed previously, may be added to lock tag assembly  130  to rubber patch  140  if there is a concern about rotation of tag assembly  130  with respect to rubber patch assembly. Another method of locking tag assembly  130  to rubber patch  140  is to insert a piece of material (not shown) into at least one slot  144 , for example by an interference fit between the slot and the material, so that in the event of rotation of the parts with respect to one another, even if the tabs  132  and slots become aligned, tabs  132  are prevented from moving axially in the slot. It is obvious that an equivalent structure can be achieved by reversing the arrangement of slots  144 , ring  146  and tabs  132  between tab assembly  130  and housing  142 . In this arrangement, at least one tab is formed in the housing and at least one slot corresponding to tabs is formed in tab assembly.  
         [0046]    The fifth embodiment of the monitoring device (tag) and patch assembly of the invention is indicated generally by the numeral  200  in FIGS.  10 - 13 . Assembly  200  generally includes a patch  202  and a monitoring device  204  that includes a protective body and a monitoring assembly. Patch  202  is generally configured to hold monitoring device  204  in a manner that allows monitoring device  204  to be repeatedly removed from patch  202  and reattached to patch  202  so that monitoring device  202  may be selectively mounted to tire  71  by selectively mounting monitoring device  204  to patch  202 .  
         [0047]    The fifth embodiment of monitoring device  204  has an outer surface that is rounded or curved in a manner that allows the body to roll as described in U.S. Pat. No. 6,082,192. The exemplary embodiments of the invention depict monitoring devices that are,free of flat surfaces. The exemplary embodiments in these drawings depict a sphere and an oblong sphere although other shapes are contemplated by the inventors. Other embodiments of monitoring device  204  may have outer surfaces that have substantially outer curved or rounded surfaces when the outer surfaces include a plurality of small flat surfaces that cooperate to define an, outer rounded surface. These types of monitoring devices are designed to be placed loosely within a tire such that they may roll around being bounded by only the tire and the rim. Monitoring device  204  may have the same structure as the monitoring device disclosed in U.S. Pat. No. 6,082,192; the disclosures of this patent are incorporated herein by reference. As such, monitoring device  204  and those having the same type of configuration (a rounded outer surface) do not have any features that may be used to secure them to a patch. Patch  202  of the present invention is designed to hold monitoring device  204  in a fixed position with respect to tire  71  without requiring any special modification to monitoring device  204  that would prevent monitoring device  204  from being used in a tire in a loose, free rolling configuration.  
         [0048]    Patch  202  includes a base  206  and a tube section  208  that projects up from base  206 . Patch  202  may include a bonding layer  20  as described above. Tube section  208  is annular and continuous and defines a cavity  210 . Tube section  208  includes a continuous lip  211  that defines an opening  212  that provides access to cavity  210 . Lip  211  and tube section  208  are free of interruptions, such as slits, that would allow lip  211  and tube section  208  to unintentionally open when used with the rounded monitoring devices of the invention. The continuity of lip  211  increases the retaining ability of patch  202  which is important when holding a spherical, oblong sphere, or teardrop shaped monitoring device. The continuity of lip  211  also reduces the risk that lip  211  will tear during extended use. Tube section  208  tapers closed toward lip  211 .  
         [0049]    The resting position of lip  211  and opening  212  is smaller than the maximum width of monitoring device  204  such that opening  212  must be stretched wider to allow monitoring device  204  to be inserted into and removed from cavity  210 . Lip  211  thus has a closed resting position and an open stretched position. Cavity  210  has a depth that is greater than half of the height of monitoring device  204  such that tube section  208  will close around monitoring device  204  to hold it in place. The walls of tube section  208  have sufficient elasticity and extensibility such that opening  212  may be stretched open to accommodate monitoring device  204  to seat monitoring device  204  within patch  202  as depicted in FIG. 11. The elasticity of the walls allows them to return to their resting position to trap monitoring device  204  with an interference fit within patch  202 . The material of patch  202  is configured to retain these properties overtime in both hot and cold operating conditions. In exemplary embodiments, patch  202  may be fabricated from any of a variety of thermosets or thermoplastics that have desirable resiliency and aged properties.  
         [0050]    Opening  212  may be centered about the longitudinal axis of patch  202  such that opening  212  is directed toward the center of tire  71  when patch  202  is mounted to tire  71 . Centrifugal forces will thus force monitoring device  204  against patch  202 .  
         [0051]    The inner surface  214  that defines cavity  210  may be curved to substantially match the outer curvature of monitoring device  204  as shown in FIG. 11. In other embodiments of the invention, the inner surface  214  may be configured such that an air pocket is disposed between base  206  and monitoring device  204 .  
         [0052]    In the embodiment of the invention depicted in FIG. 11, monitoring device  204  is oblong and is positioned with its largest diameter substantially perpendicular to the longitudinal axis of patch  202 . Device  204  may be 3 to 5 percent out of round to achieve the benefits of an oblong device. The inventors also contemplate that patch  202  may be configured to receive monitoring device  204  with the smallest diameter of monitoring device  204  substantially perpendicular to the longitudinal axis of patch  202 . An oblong configuration helps properly align monitoring device  204  within patch  202  when vibration forces move monitoring device  204  with respect to patch  202 .  
         [0053]    A predictable proper alignment is important when monitoring device  204  has an antenna  218  that is tuned to function better when positioned in a specific direction. For example, antenna  218  may be aligned with the longest dimension of monitoring device  204  so that the user will known the orientation and can orient antenna  218  with respect to tire  71 .  
         [0054]    The proper alignment of monitoring device  204  is also important so that the breathing tube  219  for the pressure sensor remains positioned within opening  212 .  
         [0055]    The proper alignment is also important when monitoring device  204  has a retraction opening  220  that allows a tool or retraction device  222  to engage monitoring device  204  and pull it from patch  202  as shown in FIGS. 12 and 13. Opening  220  allows at least a portion of device  222  to be inserted into the body of device  204  such that device  204  may be pulled from patch  202 . FIGS. 14 and 15 depict a sixth embodiment wherein monitoring device  204  is spherical. Another method of removing monitoring device  204  from patch  202  is to squeeze tube section  208  adjacent base  206  to force monitoring device  204  out of patch  202 . The squeezing force may be used in conjunction with tool  222 .  
         [0056]    Patch  202  has rounded and curved walls and surfaces that lack points where stresses are concentrated. The lack of stress concentration increases the durability of patch  202 . Tube section  208  may also be configured to absorb vibrational forces. Assembly  200  also has the advantage that monitoring device  204  will not harm tire  71  if monitoring device  204  falls out of patch  202  because monitoring device is designed to be used loosely within tire  71  and includes no sharp edges that could damage tire  71 .  
         [0057]    The seventh embodiment of the monitoring device (tag) and patch assembly of the invention is indicated generally by the numeral  300  in FIGS.  16 - 17 . Assembly  300  generally includes patch  202  and an encapsulated monitoring device  304  having a protective body  305  and a monitoring assembly  306 . Monitoring assembly  306  includes an antenna  307  and the components  308  that are necessary to monitor and transmit the conditions of the tire.  
         [0058]    As described above,,patch  202  is generally configured to hold monitoring device  304  in a manner that allows monitoring device  304  to be repeatedly removed from patch  202  and reattached to patch  202  so that monitoring device  202  may be selectively mounted to tire  71  by selectively mounting monitoring device  304  to patch  202 . In the seventh embodiment of invention, monitoring device  304  is teardrop shaped with the rounded head  310  of the teardrop being held by patch  202  in the manner described above. The tapered tail portion  311  of monitoring device  304  extends out of patch  202  into the interior of tire  71 .  
         [0059]    Antenna  307  of the monitoring system may be positioned in tail portion  311  with components  308  being disposed in head  310 . Antenna  307  is parallel to the longitudinal axis of patch  202 . Antenna  307  is thus disposed substantially perpendicular to the surface of patch  202  that engages tire  71 . This configuration allows antenna  307  to be disposed radially with respect to tire  71  when patch  202  is attached to the crown portion of tire  71  as depicted in FIG. 16.  
         [0060]    [0060]FIG. 18 depicts an eighth embodiment of the invention wherein the monitoring device  320  has a freely extending antenna  307 . Antenna  307  extends straight from patch  202  as described above.  
         [0061]    The ninth embodiment of the assembly is indicated generally by the numeral  350  in FIG. 19. Assembly  350  includes a patch  352  and a monitoring device  354  that includes a protective body  356  and a monitoring assembly  358 . Ninth embodiment  350  is also teardrop shaped but the head  360  of the teardrop is threaded to cooperate with threads defined by patch  352  to hold device  354  in place.  
         [0062]    The tenth embodiment of the assembly is indicated generally by the numeral  400  in FIG. 20. Assembly  400  includes a patch  402  and a monitoring device  404  that includes a protective body  406  and a monitoring assembly  408 . Monitoring device  404  is the same as monitoring device  354  described above. In the tenth embodiment, monitoring device  404  is not directly connected to patch  402 . In this embodiment, assembly  400  includes an intermediate housing  410  that is attached to patch  402 . Monitoring device  404  is connected to housing  410  when it is mounted.  
         [0063]    Housing  410  may be fabricated from the same material as protective body  406  or another material more rigid than the material of patch  402 . In one embodiment of the invention, housing  410  is encapsulated around the upper portion of patch  402 . In other embodiments, housing  410  may be adhesively connected or mechanically connected to patch  402 .  
         [0064]    Housing  410  defines a cavity  412  adapted to receive all of, or a portion of, monitoring device  404 . Housing  410  and monitoring device  404  define cooperating threads  414  that allow monitoring device  404  to be selectively attached to and removed from housing  410 . In addition to threads  414 , any of the other attachment arrangements described above may be used without departing from the concepts of the invention.  
         [0065]    While in accordance with the patent statutes, the best mode and preferred embodiment has been set forth above, the scope of the invention is not limited thereto, but rather by the scope of the attached claims.