Abstract:
A device is provided for placing one or more sensors along the inside surface of a tire. The device can accommodate tires of different shapes and sizes as well as projecting features along the inside surface of the tire. In one embodiment, sensors can be inserted into the interior of the tire and simultaneously deployed along the inside surface of both sidewalls. This embodiment of the device allows for repeated insertion and withdrawal of the sensors over a range of tire sizes so as to automate steps in the inspection process.

Description:
FIELD OF THE INVENTION 
       [0001]    The subject matter of the present disclosure relates generally to a device for placing one or more sensors inside a tire. 
       BACKGROUND OF THE INVENTION 
       [0002]    In the manufacture, retreading, and use of tires, the temporary placement of one or more sensors along the inside surface of the tire for inspection is useful. Through such inspection, the sensors can be used to obtain important measurements, testing, and other information for both new and used tires. Such information can sometimes be used to determine e.g., whether certain defects and/or damage are present that might not otherwise be visible to the naked eye or obtainable from outside the tire. 
         [0003]    By way of example, a known tire construction uses reinforcement cords or support elements that extend from bead to bead through the sidewalls, shoulders, and tread section of the tire. Sometimes referred to collectively as the tire carcass, these cords are typically anchored in the beads and maintain the overall shape of a pneumatic tire as the tire is inflated and used. Such cords are usually oriented substantially along the radial direction (a direction perpendicular to the axis of rotation) through the sidewalls and can include e.g., a ferrous metal. 
         [0004]    During use of the tire, these cords may be damaged e.g., from impact with objects in the roadway, travel over curbs, and other damaging events. In some situations, the cords may be completely broken during such an event. Unfortunately, this damage may not be readily discoverable from a visual inspection of the exterior of the tire because the cords are contained within the rubber materials used to construct the tire. 
         [0005]    Commercial tires are commonly reused after a process referred to as retreading. With retreading, worn tread is removed from the tire and a new tread belt or tread section is installed onto the tire. Replacement of the tread is less expensive than replacing the whole tire and allows additional mileage to be obtained using the same tire carcass. 
         [0006]    Before replacing the tread, however, it is advantageous to inspect the tire, including the cords of the carcass, for damage or wear. In certain situations, inspection may reveal that replacement or other repair of the tire is required rather than retreading. However, as stated above, not all damage to interior elements such as e.g., the cords of the carcass are readily apparent from a visual inspection alone. As the cords for commercial tires such as heavy truck tires are frequently constructed from a ferrous material, one or more sensors can be used to detect cord breaks not otherwise ascertainable from a visual inspection of the tire. 
         [0007]    It is desirable to automate inspection processes such as the one described above so that multiple tires may be inspected economically and expediently. Certain challenges are presented for such automation. For example, tires come in a variety of shapes and sizes. The profile and width (along the axial direction) can vary substantially from tire to tire. Some sensors require placement at the inside surface of the tire either in contact with the inside surface or in close proximity thereto. In addition, during certain tire inspections, the tire may need to be rotated during the inspection process so that the sensor(s) can scan the entire sidewall. However, tires may have one or more features along the inside surface of the sidewall such as onboard sensors, patches, and other devices that may project above the inside surface. These features can damage or otherwise interfere with a sensor attempting to scan the inside surface. 
         [0008]    Accordingly, a device that can properly position one or more sensors along the inside surface of the tire would be useful. Such a device that can be repeatedly deployed along the inside surface of tires of varying shapes and sizes would also be beneficial. Such a device that can also accommodate features projecting from the inside surface of the tire would be helpful. The ability to deploy one or more of such devices simultaneously along both sidewalls of the tire would be particularly useful. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention provides a device for placing one or more sensors along the inside surface of a tire. The device can accommodate tires of different shapes and sizes as well as projecting features along the inside surface of the tire. In one embodiment, sensors can be inserted into the interior of the tire and simultaneously deployed along the inside surface of both sidewalls. This embodiment of the device allows for repeated insertion and withdrawal of the sensors over a range of tire sizes so as automate steps in the inspection process. Additional objects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention. 
         [0010]    In one exemplary embodiment, the present invention provides a device for sensor placement within a tire having an inside surface and a pair of opposing sidewalls. The device includes a pair of sensor supports. Each sensor support includes a sensor for positioning along the inside surface of the tire at one of the opposing sidewalls; a substrate upon which the sensor is supported; a bracket; and a plurality of support arms extending between the substrate and the bracket. Each support arm has a first end that is rotatably connected with the bracket and a second end that is rotatably connected with the substrate whereby the substrate can pivot relative to the bracket. A pair of rollers are connected with the bracket and are rotatable relative to the bracket. The rollers are spaced apart from each other and positioned in an opposing manner about the bracket. The pair of rollers are configured for riding along the inside surface of the tire. A biasing element is attached with the bracket and is configured for urging the substrate and sensor towards the inside surface of the tire. 
         [0011]    In another exemplary embodiment, the present invention includes a sensor support for placement of a sensor within a tire. The tire has an inside surface and a pair of opposing sidewalls. The sensor support includes a sensor for positioning along the inside surface of the tire at one of the opposing sidewalls, a substrate upon which the sensor is supported, a bracket, and a plurality of support arms extending between the substrate and the bracket. Each support arm has a first end that is rotatably connected with the bracket and a second end that is rotatably connected with the substrate whereby the substrate can pivot relative to the bracket. A pair of rollers are connected with the bracket and rotatable relative to the bracket. The rollers are spaced apart from each other and positioned in an opposing manner about the bracket. The pair of rollers are configured for riding along the inside surface of the tire. A biasing element is attached with the bracket and is configured for urging the substrate and sensor towards the inside surface of the tire. 
         [0012]    These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
           [0014]    An exemplary embodiment of a device of the present invention is depicted in  FIG. 1  with a side view. The device is shown in a first position outside the tire.  FIG. 1  also provides a cross-sectional view of an exemplary tire as may be used with the present invention. 
           [0015]      FIG. 2  illustrates the exemplary embodiment of  FIG. 1  where the device is shown in a second position inside the tire. In  FIGS. 1 and 2 , the arrows U and D denote the directions up and down with respect to the vertical direction V. 
           [0016]      FIG. 3  is a perspective view of an exemplary embodiment of a device of the present invention. 
           [0017]      FIG. 4  is a rear view of the exemplary device of  FIG. 3 —i.e., a view from the side opposite to the sensor. 
           [0018]      FIG. 5A  provides a side view of the exemplary device of  FIG. 3  in a position the device would generally assume against an inside surface of a tire. 
           [0019]      FIG. 5B  is also a side view of the exemplary device of  FIG. 3 —albeit in a position the device would generally assume when not placed against the inside surface of the tire. 
           [0020]      FIG. 6A  is an end view of the exemplary device of  FIG. 3  in a position the device would assume against an inside surface of a tire. 
           [0021]      FIG. 6B  is an end view of the exemplary device of  FIG. 3 —albeit in a position the device would assume when not placed against the inside surface of the tire. 
           [0022]      FIG. 7  is a side view—opposite to that shown in  FIGS. 5A and 5B —of the exemplary device of  FIG. 3 . 
           [0023]      FIG. 8  is a perspective view of another exemplary embodiment of the present invention while  FIG. 9  is a top view of the same exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    For purposes of describing the invention, reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
         [0025]      FIGS. 1 and 2  depict an exemplary embodiment of a device  100  for sensor placement into the inside  64  of a tire  50 . In  FIG. 1 , device  100  is depicted in a first position in which a pair of sensor supports  102 ,  104  are adjacent to each other for purposes of insertion or removal from the inside  64  of the tire  50 . In  FIG. 2 , device  100  is positioned in a second position along the inside  64  of tire  50  where sensor supports  102 ,  104  are spaced apart from each other in an opposing manner to position sensors along a respective inside surface  66  and  68  of tire  50 . 
         [0026]    Tire  50  is depicted in a cross-section taken along the tire&#39;s meridian plane, which is defined herein as the plane that includes the axis about which the tire rotates. The meridian plane is also perpendicular to equatorial plane EP, which bisects tire  50  into two portions along the center of tread portion  52  as shown. Tire  50  also defines a radial direction R and an axial direction A, which is parallel to the axis about which tire  50  rotates. Tire  50  includes tread portion  52  along a crown  72  that extends between sidewalls  54  and  56 . A carcass  62  extends through sidewalls  54 ,  56  to respective beads  58 ,  60 , which are positioned in an opposing manner about tire  50 . Tire  50  is provided by way of example only. The present invention may be used with a variety of tire shapes and configurations in addition to that shown in the figures. 
         [0027]    The pair of sensor supports  102 ,  104  are mounted upon a mechanism for positioning the sensor supports  102 ,  104  inside the tire in an opposing manner as shown in  FIG. 2 . For this exemplary embodiment, the mechanism is provided as a scissor linkage  134  connected to a frame  140 . Once tire  50  is suspended adjacent frame  140  for an inspection, frame  140  can move scissor linkage  134  with sensor supports  102 ,  104  up and down (arrows U and D) along radial direction R and left and right (arrows L and R) along axial direction A to the position shown in  FIG. 1  for insertion into the inside  64  of tire  50 . Once lowered (arrow D) to the inside  64  of tire  50 , an actuator  138  ( FIG. 2 ) can be used to expand scissor linkage  134  so that the sensor supports  102 ,  104  are moved into the second position shown in  FIG. 2 —where sensor supports  102 ,  104  each position one or more sensors along inside surfaces  66 ,  68  of respective sidewalls  54 ,  56 . During the inspection, tire  50  may be rotated so as to scan the sidewalls  54 ,  56 . Supplemental rollers  148 , 150 , supported upon scissor linkage  134  between sensor supports  102 ,  104 , make contact with inside surface  70  in crown  72  for additional stability. Upon completion of the tire inspection, actuator  138  can be used to retract the scissor linkage  134  to a position where the sensor supports  102 ,  104  are adjacent to each other, whereby the pair can be readily removed from the inside  64  of tire  50  using frame  140 . 
         [0028]    Various views of sensor support  102  are shown in  FIGS. 3, 4, 5A, 5B, 6A, 6B , and  7 —it being understood that the construction and operation of sensor support  104  is identical in all important aspects. Sensor support  102  includes a substrate  110  upon which one or more sensors  108  ( FIGS. 6A and 6B ) may be supported. For example, sensors  108  may be mounted on surface  106  or located just beneath surface  106 . Other configurations may be used as well. Sensors  108  are configured for positioning along the inside surfaces  66 ,  68  of sidewalls  54 ,  56  of tire  50 . Sensors  108  could include, for example, a plurality of Hall Effect sensors used in conjunction with a magnet (not shown) to detect damage to ferrous reinforcements in carcass  62 . For this exemplary embodiment, multiple sensors are aligned along a longitudinal direction L ( FIGS. 5A and 5B ) of substrate  110 . Other sensor types and configurations may be used as well. 
         [0029]    Substrate  110  is connected with a bracket  112  by a plurality of support arms  114  extending therebetween. For this exemplary embodiment, a first pair of support arms  116  and a second pair of support arms  118  are used. Each pair of supports arms  116 ,  118  are positioned on opposing sides of bracket  112 . Each support arm has a first end  120  that is rotatably connected with bracket  112  and a second end  122  rotatably connected with substrate  110 . Each pair of supports  116 ,  118  is rotatable about an axis. For example, first pair of support arms  116  are rotatable about axis S-S ( FIGS. 3 and 7 ). As such, substrate  110  is pivotable relative to bracket  112 . 
         [0030]    A pair of rollers  124 ,  126  are connected with bracket  112  and are rotatable relative to bracket  112 . As shown, rollers  124 ,  126  are spaced apart from each other and are positioned on opposing sides of bracket  112 . During inspection of tire  50 , rollers  124 , 126  ride along the inside surfaces  66 ,  68  of tire  50  as it is rotated past sensors  108 . To facilitate this movement, rollers  124 ,  126  are angled from each other to more closely match the curved insides surface  66 ,  68  of tire  50 . More particularly, as best seen in  FIG. 7 , roller  124  rotates about an axis R 1  while roller  126  rotates about an axis R 2 . As shown, axis R 1  and R 2  are non-parallel to each other and also form a non-zero, acute angle θ from axis S-S about which the first end  120  of the first pair of support arms  116  are rotatable. In one exemplary embodiment, angle θ is in the range of about 10 degrees to about 45 degrees. In another exemplary embodiment, angle θ is about 16 degrees. In still another exemplary embodiment, angle θ is about 30 degrees. Other angles may be used as well. 
         [0031]    A biasing element  128  is attached with bracket  112  and is configured for urging substrate  110  towards the inside surface of the tire. More particularly, referring back to  FIGS. 1 and 2 , for this exemplary embodiment biasing element  128  is configured as a compression spring  128  that urges supports  102 ,  104  towards insides surfaces  66 ,  68  and away from each other. 
         [0032]    Accordingly, when sensor supports  102 ,  104  are deployed and make contact with the inside surfaces  66 ,  68 , their position shifts. Using sensor support  102  for continued description and example, sensor support  102  will shift (arrow I in  FIG. 5B ) from a first position shown in  FIGS. 5B and 6B , to a second position shown in  FIGS. 5A, 6A, and 7 . In this second position, substrate  110  with one or more sensors  108  can ride or float (arrows I and O) along the inside surface of tire  50  as it is rotated. Further, rollers  124 ,  126  will roll along the inside surface of tire  50  to facilitate such movement. 
         [0033]    If the sensor support  102  encounters a projection along the inside of tire  50  during such rotation, the pivoting action of supports arms  114  allows the substrate  110  along with sensor(s)  108  to shift position or move (arrows I and O) relative to the inside surface so that sensor support  102  can pass the projection without damage. The action of biasing element  128  will allow support  102  to move away from the inside surface of tire  50  while also urging sensor support  102  back towards the inside surface once the projection or surface anomaly has passed. Adjustments can be made to the force provided by biasing element  128  (such as e.g., using a compression spring of different stiffness) to provide the best amount of pressure, wear, etc. for sensor support  102 . The removal of support  102  from contact with inside surface  66  allows support  102  to shift back (arrow O) to the position shown in  FIGS. 5B and 6B . 
         [0034]    Additionally, each sensor support  102 ,  104  is rotatably connected with scissor linkage  134 . Using sensor support  102  again for example, support  102  is rotatably connected to a linkage arm  132  as shown in  FIGS. 2, 6A, 6B, and 7 . As such, sensor support  102  can move along directions P as shown in  FIG. 7 . A torsion spring  130  is supported upon linkage arm  132  and is connected with bracket  112 . Torsion spring  130  is configured for urging sensor support  102  to rotate relative to the linkage arm  132 . 
         [0035]    Referring back to  FIG. 1 , in this first position, the torsion spring associated with each sensor support  102 ,  104  causes the supports to assume the position shown where they are adjacent to each other and axis S-S of the respective supports are substantially parallel. Once deployed against the inside surfaces  66 ,  68  as shown in the second position of  FIG. 2 , contact with tire  50  operates against the torsion spring and causes each support  102 ,  104  to rotate into a position determined by the shape of the inside surfaces  66 ,  68  interacting with the rollers and substrate of each support  102 ,  104 . Once removed from contact with inside surface  66 ,  68 , the torsion springs will cause each sensor support  102 ,  104  to rotate back in the more compact position shown in  FIG. 1  for easier removal from the inside  64  of tire  50 . The ability of each sensor support  102 ,  104  to rotate along the direction of arrow P ( FIG. 7 ) also helps accommodate tires of different shapes and configurations for testing. 
         [0036]    The present invention is not limited to the particular frame  140  with scissor linkage  134  shown in  FIGS. 1 and 2  as other frame configurations may be used as well. For example,  FIGS. 8 and 9  show another exemplary frame  140  in which sensor supports  102 ,  104  are rotatably mounted onto a pair of pivot arms  142 ,  144 . Each pivot arm  142 ,  144  has a distal end  152  and a base end  154 . The distal end  152  of each pivot arm  142 ,  144  is rotatably connected to its respective sensor support  102 ,  104 . An actuator  146  can be used to move arm  142  left and right relative to frame  140  for positioning along the inside  64  of tire  50 . The operation and construction of sensor supports  102 ,  104  is otherwise as previously described. Other constructions for frame  140  and for a mechanism that positions sensor supports  102 ,  104  inside the tire may be used as well. 
         [0037]    While the present subject matter has been described in detail with respect to specific exemplary embodiments and methods thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations, and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art using the teachings disclosed herein.