Abstract:
A method is provided for protecting an electronics device, attached to a tire, during tire inspection, comprising placing a barrier in proximity to the electronics device wherein the barrier surrounds the electronics device, and removedly affixing the barrier to the tire with magnets.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a protective device, and more specifically for a method and device for providing protection to tire electronics during inspection. 
     2. Background 
     The incorporation of electronic devices with pneumatic tire and wheel structures provides many practical advantages. Tire electronics may include sensors and other components for relaying tire identification parameters and also for obtaining information regarding various physical parameters of a tire, such as temperature, pressure, tread wear, number of tire revolutions, vehicle speed, etc. Such performance information may become useful in tire monitoring and warning systems, and may even potentially be employed with feedback systems to regulate proper tire and/or vehicle parameters. 
     While the use of tire electronics has many practical advantages, the presence of such tire electronics may create difficulties during periods of a tire&#39;s useful life. One particular period occurs when a tire equipped with such tire electronics is brought to a facility for recapping. 
     One commonly used method for inspecting a tire for anomalies prior to recapping such tire involves the use of a high voltage probe in the form of a wire. During tire inspection, high voltage energized wire loops are brushed against the interior of the tire causing sparks to jump from the wire to the site of any anomalies. Such high voltage discharges may damage the tire electronics, and moreover, the wire itself may snag the electronics package causing mechanical damage to the tire electronics package. 
     SUMMARY OF THE INVENTION 
     A method is provided for protecting an electronics device, attached to a tire, during tire inspection, comprising placing a barrier in proximity to the electronics device wherein the barrier surrounds the electronics device, and removedly affixing the barrier to the tire. Further, a method is provided for protecting an electronics device, attached to a tire, during tire inspection, comprising placing a barrier in proximity to the electronics device wherein the barrier surrounds the electronics device, and removedly affixing the barrier to the tire with rare earth magnets. A barrier is provided for protecting an electronics device during tire inspection, the electronics device attached to a tire, the barrier comprising magnets embedded in a flexible material, wherein the flexible material comprises a rubber layer no greater than 1 millimeter thick, the barrier further comprises a first set of rubber reinforcements on said barrier, and a second set of one rubber reinforcement located proximal to the center of the barrier, each of reinforcements having a thickness greater than 1 millimeter, and the magnets are embedded in the first set of rubber reinforcements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a tire and alternative locations for tire electronic devices. 
         FIGS. 2 and 2   a  are top and side cross sectional views of a first embodiment of the present invention showing physical protection of a tire electronics device. 
         FIG. 3  is a top view of a tire protection patch. 
         FIG. 4  is a bottom view of a tire protection patch. 
         FIG. 5  illustrates further embodiments of the present technology where different materials having different electrical properties may be employed to provide protection of a tire electronics device. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Advantageously, particular embodiments of the present invention provide a method that offers protection of electronic devices from damage during an inspection of a tire. Other embodiments provide a protective barrier that can be attached to the tire to protect the tire electronics. The technology has particular applicability to a tire inspection environment and the protection of associated tire electronics but is applicable to other testing environments as well. 
     Referring now to the drawings,  FIG. 1  illustrates several alternative locations where tire electronics devices may be mounted in, on or within a tire in accordance with certain embodiments of the present invention. As illustrated in  FIG. 1 , one or more tire electronics devices  90  may be associated with the tire  10  by mounting such devices on the outside of the tire side wall  92 , on the inside of the sidewall  94 , on the inner liner of the tire under the crown  96 , or physically embedded within the tire structure as illustrated by the dotted line rectangle  98 . Any, some, or all of these locations might be used for tire electronics device locations in any one tire. Moreover, plural tire electronics devices may be arranged such that a plurality of conditions may be detected to obtain the widest possible range of discernible data. 
     It should be noted that the present disclosure is not limited to the testing of tires and methodologies for the protection of electronic devices associated with such tires. In particular various protection methodologies described herein may also be applicable in other environments where different testing techniques may be applied and wherein electronic devices associated with devices or items under test in such environments undesirably may be subject to damage as a result of such testing techniques. A non-limiting examples of such testing environments may include testing associated with EMP (Electro Magnetic Pulse). 
       FIGS. 2 and 2   a  illustrate a tire testing operation,  FIG. 2  showing a top view and  FIG. 2   a  showing a side cross-sectional view. Wires  310  brush across the inside surface  12  of tire  10 . In an actual test, tire  10  may be rotated while wires  310  remain stationary to produce relative motion between the tire  10  and wires  310 . By virtue of being coupled by way of metal header  300  to a high-voltage power supply, brushing wires  310  across the tire surface  12  will result in a spark between one or more of wires  310  and any anomaly in the tire to a grounded conductive plate or roller  312  (not shown in  FIG. 2 ). The provision of the protective barrier  200  and its optional extension  210  prevents wires  310  from coming into contact with tire electronics device  90  thereby protecting the device from damaging electrical discharge. As a non-limiting example, the high voltage supply coupled via metal header  300  to wires  310  may correspond to a supply having a peak output of about 80 kV DC. 
     As illustrated in  FIGS. 2 and 2   a , a portion of a tire  10  shows a tire electronics device  90  secured to an inside surface  12  of tire  10 . In this embodiment, a protective barrier  200  is placed on the inside tire surface  12  to provide physical protection for tire electronics device  90  from contact by wires  310 . Wires  310  may take the form of conductive key chains. As shown, the protective barrier  200  is placed so that the barrier at least partially surrounds tire electronics device  90  and may, by way of an optional portion  210  completely surround the tire electronics device  90 . In a preferred embodiment, the protective barrier  200  may be removed and reattached, for example, by magnets which are attracted to metal within the tire. The electronics device  90  will typically consist of an tag (such as an RFID tag) and an attached antenna. 
     The protective barrier  200  may take the form of a patch  202 , as shown in  FIG. 3 . The patch  202  may be formed of rubber or it may be formed of another flexible material, such as a polymer. Suitable rubber may include diene rubber known to one of ordinary skill in the art to be rubber resulting at least in part, i.e., a homopolymer or a copolymer, from diene monomers, i.e., monomers having two double carbon-carbon bonds, whether conjugated or not. 
     The patch  202  itself is thin enough so that it shapes itself to the contours of the tire. Particular embodiments provide a patch  202  having a thickness between 0.8 and 2 millimeters. On the patch  202  there may be a plurality of reinforced areas of increased thickness  104 , and the reinforced areas  104  may be made of the same material as the patch  202 . For example, in the center of the patch  202  there may be a reinforced area  104  which will serve to provide extra protection to the electronics device underneath. As a non-limiting example, the reinforcements may be in the shape of a spherical dome. As discussed above, the protective patch  202  should surround the electronics device  90  either partially or completely, but it also should not be so large as to interfere with the operation of the testing device. 
     The magnets  102  may be embedded in the reinforced areas  104  on the patch  202 , or directly on the patch  202 . In a particular embodiment, the magnets  102  do not protrude past the surface of the patch  202  to prevent a space from opening between the surface of the patch  202  and the surface of the tire  10  to which it is attached.  FIG. 4  is an exemplary embodiment illustrating where the magnets  102  are embedded in the reinforced areas  104  on the protective patch  202 . Some conventional radial tires use multiple belt plies with steel reinforcing materials. Furthermore, some tires utilize a metallic carcass. In an embodiment where the barrier is attached to the crown  96 , the magnets  102  are attracted to the steel plies within the tire  10 . In an embodiment where the barrier is attached to a side wall, the magnets  102  are attracted to the metal in the carcass. As pointed out above, the patch  202  may be removed and reattached as necessary. In an alternative to embedding the magnets  102  within the patch  202 , the patch  202  may also be placed between the magnets  102  and the tire ply. 
     In particular embodiments, the magnets  102  used for attaching the patch  202  to the tire  10  are rare-earth magnets. Rare-earth magnets are strong, permanent magnets made from alloys of rare earth elements. Rare-earth magnets are substantially stronger than iron or alnico magnets. Magnetic fields produced by rare-earth magnets can be in excess of 1.2 teslas. Iron or ceramic magnets typically exhibit 50 to 100 milliteslas. Neodymium magnets are a common, powerful and affordable type of rare-earth magnet. Neodymium magnets are made of neodymium, iron and boron. The formula for Neodymium magnets is Nd 2 Fe 14 B. Samarium-cobalt magnets, having the formula SmCo 5 , are another common type of rare-earth magnets that may be used. It is to be understood, however, that the invention is not limited to rare earth magnets, and any variety of strong, permanent magnets may be used. 
     Particular embodiments of the present invention further include a number of additional protective features employed to provide protection to the tire electronics device  90 ; these involve tire electronic device protection methodologies wherein a barrier of varying electrical properties is either temporarily or permanently applied over the tire electronics device. 
       FIG. 5  illustrates these embodiments. A barrier  200  of insulating material is temporarily or permanently installed over the tire electronics device  90  thereby preventing formation of electronics damaging sparks. A second embodiment provides for the temporary or permanent installation of a barrier  200  of conductive material over the tire electronics device  90 . This provides a Faraday cage configuration that draws an arc from the high-voltage energized wires  310  but prevents any voltage gradients within the package forming the tire electronics device  90 . The electrical charges within the enclosing conductor repel each other and will therefore reside on the outside surface of the cage 
     Finally a third, particular configuration for the embodiments corresponds to a barrier  200  of resistive material over the tire electronics device  90 . The barrier might have a surface resistivity of at least 10 12  ohms/sq and a volume resistivity of at least 10 9  ohms*cm. Such a resistive material barrier may or may not allow an arc to form but controls both the magnitude and the rate-of-rise of the current in the material to levels that are not damaging to the tire electronics device  90 . As a non-limiting example of suitable resistive materials, carbon impregnated rubber may be employed with the carbon particle concentration being adjusted to achieve magnitude and rate-of-rise of current limitations as desired. 
     It should be understood from the foregoing description that various modifications and changes may be made to the embodiments of the present invention without departing from its true spirit. The foregoing description is provided for the purpose of illustration only and should not be construed in a limiting sense. Only the language of the following claims should limit the scope of this invention.