Patent Publication Number: US-2023150220-A1

Title: Non-destructive belt detection apparatus and method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/216,263, filed Dec. 11, 2018, which claims priority to U.S. Provisional Patent Application No. 62/612,216, filed Dec. 29, 2017, each of which is incorporated herein by reference in its entirety. 
     The application has been filed following the application of John Lindsay titled “Automated Tire Buffing Identification Apparatus and Method,” published as U.S. 2017/0176175 on Jun. 22, 2017, which is herein incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to devices and methods for retreading tires, and more particularly to devices and methods for tire buffing. 
     BACKGROUND 
     A tire casing selected for retreading may be buffed to remove excess rubber and provide a substantially evenly textured crown for receiving a tread strip or other tread. Tire casings may include a belt package (a package of steel belts or cables) underlying the road-engaging surface (e.g., the original tread) of the tire. The casing may be buffed to leave only a predetermined thickness, e.g., 3/32 of an inch, of material remaining over the top belt. The shoulder of the casing may be also buffed (trimmed) to eliminate or reduce voids or patterns in the shoulder created by the original tread, and to provide, typically, a relatively straight profile between the casing side walls and the crown. 
     A cured tread strip, which may be of a width corresponding to the width of the crown of the casing, may be cut to the length corresponding to the casing circumference and disposed over the casing crown. Continuous replacement treads in the shape of a ring (i.e., ring treads) have also been used to retread the buffed casing. Thereafter, the assembly may be placed within a curing chamber and subjected to elevated pressure and temperature for a predetermined period of time. The combination of exposure to elevated pressure and temperature for a duration of time binds the cushion gum to both the tire casing and the new tire tread. 
     The shape and contour of the tire casing being buffed may be important to determining the necessary buffing operations that need to be performed. Some buffing machines are manually operated such that the final product of buffing is dependent on the skill of the operator. In other situations, data pertinent to buffing is stored in the buffing machine and such data may be extracted by the operator for proper buffing to proceed. If the shoulder areas are not sufficiently buffed and trimmed, the tread edges may come loose and/or the cushion gum extending beyond the tread edges will not bond to the casing shoulder. Such problems can reduce the longevity of the retreaded tire and adversely impact the appearance of the retreaded tire. In addition, if the crown surface of a tire casing is overbuffed and the belt package is exposed, the tire casing may be irrecoverably damaged. Further, tire casings are variable in size and shape across brands, within brands, and even as casings age. As such, errors and damage occur during buffing processes even if a tire casing is accurately identified and buffed within corresponding, standard parameters. 
     Thus, there exists a need for a tire buffing machine capable of accounting for variance across tire casings during the buffing process. 
     SUMMARY 
     A tire buffing machine may include a tire hub assembly selectively rotating a casing mounted thereon, a buffer configured to buff the casing mounted on the tire hub assembly, a belt detection apparatus having two or more sensors configured to detect a first belt depth of one or more belts at a first lateral position within a tire casing and a second belt depth of the one or more belts at a second lateral position within the tire casing, and an electronic controller. The electronic controller may be communicatively coupled to the buffer and the belt detection apparatus. The electronic controller may be programmed to determine the first belt depth and the second belt depth based on the two or more sensors of the belt detection apparatus. The electronic controller may be programmed to adjust the operation of the buffer based on the first belt depth or the second belt depth. 
     In some instances, a tire buffing machine includes a controller that may enable the tire buffing machine to buff a casing while monitoring the location of a belt package disposed therein, the controller including instructions stored on non-transient data media causing the controller to perform operations. The operations may include maintaining a database containing a plurality of casing profiles, each casing profile including corresponding buffing parameters. The operations may further include operating a buffer to buff the casing in accordance with buffing parameters associated with one of the plurality of casing profiles. The operations may include determining a first belt depth at a first lateral position within a tire casing and a second belt depth at a second lateral position within the tire casing using a belt detection apparatus having two or more sensors configured to detect the first belt depth and the second belt depth within the tire casing. The operations may include adjusting the operation of the buffer based on the first belt depth or the second belt depth. 
     In some embodiments, a method may be used to manufacture a retreaded tire casing. The method may include maintaining, in a database, a plurality of casing profiles, each casing profile including corresponding buffing parameters. The method may further include operating a buffer to buff the casing in accordance with buffing parameters in one of the plurality of casing profiles. The method may include determining, by a controller, a first belt depth at a first lateral position within a tire casing and a second belt depth at a second lateral position within the tire casing using a belt detection apparatus having two or more sensors configured to detect the first belt depth and the second belt depth within the tire casing. The method may include adjusting, by the controller, the operation of the buffer based on the first belt depth or the second belt depth. 
     The features of the present invention will become apparent to one of ordinary skill in the art upon reading the detailed description and claims, in conjunction with the accompanying drawings, provided herein. The scope of this disclosure includes various changes and modifications to the embodiments without departing from the spirit and scope of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic view of a belt detection and tire buffing apparatus. 
         FIG.  2    is a front perspective view of a belt detection apparatus. 
         FIG.  3    is a rear perspective view of the belt detection apparatus of  FIG.  2   . 
         FIG.  4    is a side view of the belt detection apparatus of  FIG.  2   , including a mount assembly. 
         FIG.  5    is a block flow chart diagram of a method of buffing a tire casing, according to an example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative tire buffing apparatus  100  is shown in  FIG.  1   . The apparatus  100  includes a rasp pedestal  102 , a controller  104 , and a measurement subsystem including a belt detection apparatus  106 . 
     The rasp pedestal  102  is configured to remove material from a tire casing  112  to predetermined tire casing parameters with a desired surface texture. In various embodiments, the rasp pedestal  102  may include a rasp head housing a rasp or a rotary blade configured to strip material from outer surfaces of the tire casing  112 . The rasp head may further include a texturing brush, which may be applied to casing surfaces to impart a specified texture to crown and shoulder portions of the tire casing  112  to facilitate a subsequent retreading process. 
     The controller  104  is a computing system communicatively coupled to the other components of the apparatus  100 , and is configured to measure the tire casing  112  and correct the operation of the rasp pedestal  102  during a buffing process. In some embodiments, the operations discussed with respect to the controller  104  are performed by a plurality of separate controllers acting as a single controller, or a plurality of computing components of the same controller that operate the buffer and measure the tire casing  112 . 
     In some arrangements, the controller  104  includes an operator input/output (“I/O”) device and a database. The operator I/O includes hardware and associated logics sufficient to allow the controller  104  to exchange information with a human operator. For example, an input aspect of the operator I/O of the controller  104  may include any of a mechanical keyboard, a touchscreen, a microphone, a keypad, and so on. The output aspect of the operator I/O may include a digital display, one or more illuminating signal lights, speakers, and so on. The database includes a non-transient data storage medium, which may include, for example, local hard drives or a networked data server. The database stores instructions carried out by the controller  104 , including instructions for buffing procedures. The database may also include information relating to a plurality of buffing parameter profiles (e.g., desired crown and shoulder characteristics, minimum belt depths, etc.) corresponding to a plurality of tire casing sizes and specifications. As such, an operator may interact with the controller  104  via the operator I/O to select an appropriate casing profile and initiate a buffing procedure. 
     The controller  104  is electrically coupled to the rasp pedestal  102 , and may be configured to adjust the buffing process while the rasp pedestal  102  is in operation. The rasp pedestal  102  may be coupled to one or more rails, hinges, pivots, etc. and corresponding actuators configured to allow the rasp pedestal  102  and/or components disposed thereon (e.g., a rasp head) various ranges of movement relative to the tire casing  112 . In addition, the controller  104  may be communicatively coupled to one or more motors configured to effect various cut depths and movement patterns of the rasp disposed on the rasp pedestal  102 . The controller  104  can be associated with a current sensor which senses the current draw of a rasp drive motor for rotating the rasp head and the texturing device. The rasp drive motor can have a predetermined full-load capacity at which its current draw is a particular value and at which the motor can remove material from the tire casing  112  at an efficient rate while preventing damage to the motor or other components of the tire buffer. The value of the predetermined target current draw can be based upon such considerations as the capabilities of the motor driving the cutter, the maximum depth of cut for the selected cutter, the maximum traverse speed the buffer is capable of generating, and the wear of the cutter itself. The controller  104  can compare the actual current draw of the rasp drive motor to the calculated target current draw and determined whether the actual current draw is equal to the target current draw. If the actual and target current draws are different, the controller can move the rasp pedestal  102  at different rates of speed by selectively controlling the rasp moving assembly to adjust the actual current draw such that it moves toward the target current draw. The traverse rate of speed of the rasp pedestal  102  can be increased to increase the actual current draw of the motor and decreased to decrease the actual current draw of the motor. 
     The controller  104  is in data receiving communication with the belt detection apparatus  106 . In some implementations, the controller  104  may be in data receiving communication with other sensors, such as distance sensors for detecting a distance of the tire casing  112 . In some arrangements, the belt detection apparatus  106  can be mounted to the rasp pedestal  102  and can be configured to measure a distance of one or more belts  114  within the tire casing  112  with respect to the rasp pedestal  102 . 
     The belt detection apparatus  106  is a measurement device configured to determine the depth of a set of belts  114  within the tire casing  112 . The belt detection apparatus  106  may include one or more measurement sensors suited to determine distance to a metallic component (e.g., the belts  114 ) relative to the belt detection apparatus  106  itself. In some arrangements, the belt detection apparatus  106  is configured to determine the distance of the belts  114  relative to the rasp pedestal  102 , and in turn, the rasp disposed within the rasp pedestal  102 . In one arrangement, the belt detection apparatus  106  includes one or more sensors such as magnetic field sensors, inductive sensors, etc. The belt detection apparatus  106  may be able to provide the controller  104  with data indicative of a position or depth of one or more belts  114  within the tire casing  112 . In turn, the controller  104  may be configured to use the data provided by the belt detection apparatus  106  to determine a distance of one or more of the belts  114  relative to the rasp pedestal  102  or a rasp of the rasp pedestal  102 . 
     In operation, the controller  104  may use the data indicative of a distance or position between the rasp pedestal  102  or rasp and the set of belts  114  within the tire casing  112  to control the operation of the rasp. In some implementations, one or more distance sensors may be implemented to detect a distance of the tire casing relative to the rasp or rasp pedestal  102  prior to and after the rasp or rasp pedestal, such as described in U.S. patent application Ser. No. 14/972,251, entitled “Self Correcting Tire Buffing Apparatus and Method,” filed Dec. 17, 2015. In response to distance data received, the controller  104  may adjust the operation of the rasp in the rasp pedestal  102  (e.g., to reduce a cut depth if the amount of removed casing material is unexpectedly high). As such, the controller  104  may be able to adjust the buffing process to accommodate variances in the belt location  114  across various similarly sized casings, variances in casing material properties (e.g., density, hardness, etc.). Additional features and details of the buffing apparatus  100  are discussed below. 
     A tire hub assembly can be configured to provide a mount for the tire casing  112  during a buffing process. In some embodiments, the tire hub assembly is configured to engage a center aperture in the tire casing  112  (i.e., similar to a rim engaging the tire casing), orient the tire casing  112  on a center axis (i.e., a rotational axis of the tire casing), and inflate the tire casing  112 . For example, in some embodiments, the tire hub assembly includes an expandable tire chuck (i.e., an expandable rim) having a plurality of radial pistons (e.g., pneumatically or hydraulically actuated). The tire chuck of the tire hub assembly may be disposed in a contracted configuration during an initial casing mounting process, and may subsequently expand (i.e., via actuation of the plurality of radial pistons) to engage a center aperture (e.g., defined by a casing bead) of the tire casing  112 . The tire chuck may be further configured to expand in a manner sufficient to orient the tire casing  112  on a center axis. In addition, the tire hub assembly may include an airflow line in fluid providing communication with an interior portion of the tire casing  112 , thereby allowing the tire casing  112  to be inflated. The tire hub assembly may further be operatively coupled to a motor with a rotational output at the tire chuck, and as such, the tire hub assembly may cause the tire casing  112  to rotate during a buffing process. In some arrangements, the tire hub assembly is electrically coupled to the controller  104 , which may control the various operations discussed above. 
     A pedestal movement assembly is configured to provide a range of motion for the rasp pedestal  102 . The pedestal movement assembly may be configured to allow the rasp pedestal  102  to travel along an X and a Y axis to approach and position the rasp or brush with respect to a mounted casing. The pedestal movement assembly may further allow the rasp pedestal  102  to rotate about a Z axis to allow the rasp disposed therein to engage the tire casing  112  at specified angles, for example to buff shoulder portions of the casing. In one arrangement, the pedestal movement assembly includes respective sets of rails and bearings corresponding to the X and Y axes, and a pivot hinge disposed at a base portion of the rasp pedestal  102  to enable Z axis rotation. 
     In operation, an operator may dispose the tire casing  112  onto a contracted tire chuck of the tire hub assembly. The operator may use the operator I/O of the controller  104  to identify an appropriate casing profile to be applied and initiate a buffing process. The controller  104  may then cause the tire chuck of the tire hub assembly to expand, engage, and orient the tire casing  112  about a center axis. The rasp pedestal  102  may approach the tire casing  112  along an X axis via the pedestal movement assembly and perform a buffing process pursuant to a selected casing profile. 
     Referring now to  FIGS.  2 - 3   , a belt detection apparatus  200  includes a frame  210  having one or more wheels  212  that contact and roll along an exterior of a tire casing during a buffing operation. In some implementations, the wheels  212  may be omitted and the frame  210  may be positioned relative to the tire casing via a moveable arm or other support in order to maintain a constant distance from the casing. The frame  210  is pivotally mounted to a mount  218  that can be coupled to another component, such as a stand or a robotic arm (e.g., pneumatic cylinders). 
     The frame  210  includes a center sensor mount  220 , a right sensor mount  230 , and a left sensor mount  240 . The center sensor mount  220 , right sensor mount  230 , and left sensor mount  240  can be fixedly attached to the frame  210  or may be adjustably or otherwise moveably coupled to the frame  210 . The center sensor mount  220 , right sensor mount  230 , and left sensor mount  240  each include a mount for a sensor  222 ,  232 ,  242 . The sensors  222 ,  232 ,  242  can include inductive sensors or other sensors configured to detect a distance to a metallic material. The center sensor mount  220  may be configured to monitor an undertread depth of one or more belts during a buffing process. In some embodiments, one or multiple of the three sensors  222 ,  232 ,  242  may monitor an undertread depth of one or more belts during a buffing process. 
     The frame  210  includes one or more slides  214  to slide the right sensor mount  230  and/or left sensor mount  240  relative to the frame along a horizontal axis of the belt detection apparatus  200 . The horizontal axis may be parallel to an axial axis of a subject tire casing such that the right sensor mount  230  and/or left sensor mount  240  can be adjusted relative to a width of a subject tire. That is, a position of the right sensor  232  and/or left sensor  242  can be adjustable to accommodate multiple tire casing widths. In some embodiments, the right sensor  232  and/or left sensor  242  may be placed over a respective edge of the widest working belt. The right sensor  232  and/or left sensor  242  can be adjusted to a position corresponding to a respective left or right shoulder of the tire casing. That is, the right sensor  232  can be positioned over a left shoulder of the tire casing and the left sensor  242  can be positioned over the right shoulder of the tire casing. With the center sensor  222  over a central plane of the tire casing and the left and right sensors  232 ,  242  over the left and right shoulders of the tire casing, the sensors  222 ,  232 ,  242  can detect the position of the one or more belts within the tire casing at three different positions such that a minimum tire casing depth can be maintained during the buffing process even if the belts are at different depths across a cross-sectional plane of the tire casing. Thus, the sensors  222 ,  232 ,  242  can determine the depth of the one or more belts before or during the buffing process and/or monitor a position of the one or more belts during the buffing process. A lock  234 ,  244  can be selectively engaged and disengaged to secure and/or move each of the right sensor mount  230  and/or left sensor mount  240 . In some implementations, the center sensor mount  210  may also be coupled to the one or more slides  214  and be slidable or otherwise movable relative to the frame  210 . In some implementations, an actuator or other component may be integrated into the frame  210  to automatically move and/or reposition the right sensor mount  230  and/or left sensor mount  240 . In some implementations, when a tire casing type or width dimension of a tire casing is input via an operator I/O of the controller  104 , the actuator(s) can automatically adjust the position of the right sensor mount  230  and/or left sensor mount  240  to a predetermined position based on the input tire casing type or width dimension of the tire casing. Beneficially, monitoring the sensors  222 ,  232 ,  242  allows for the system to avoid the damaging belts due to an improper buff radius or a raised edge along a shoulder. 
     The belt detection apparatus  200  can also include a distance sensor  250  mounted to one of the right sensor mount  230  or the left sensor mount  240 . The distance sensor  250  may be a laser distance sensor  250  configured to measure a distance between the right sensor mount  230  and the left sensor mount  240 . The distance sensor  250  can be used to determine if there is adequate space between the right sensor  232  and the left sensor  242  such that the right sensor  232  and left sensor  242  are positioned above the left shoulder and right shoulder of the tire casing to detect a left end of the one or more belts and a right end of the one or more belts, respectively. If a distance measured by the distance sensor  250  is above or below a predetermined distance for the tire casing, then the buffing process may be aborted or not started. In some embodiments, a casing width may be the distance measured by the distance sensor  250 . In some implementations, the belt detection apparatus  200  can be coupled or mounted to a stand  290 , as shown in  FIG.  4   . In some embodiments, the frame  210  may be adjustable such that the fixed center sensor  222  is able to move left or right by moving the frame  210  left of right. 
     The three sensors  222 ,  232 ,  242  are positioned in a triangular pattern to measure distances of the one or more belts in the tire casing during a buffing process. The center sensor  222  is positioned in a center of a tire casing while the left and right sensors  232 ,  242  can be positioned over a respective left or right shoulder of the tire casing. Thus, the sensors  222 ,  232 ,  242  can measure the different distances to the one or more belts within the tire casing such that the a minimum amount of tire casing above the one or more belts can be maintained. The distance sensor  250  can be included to determine a spacing or distance between the right sensor mount  230  and the left sensor mount  240  to determine if there is adequate spacing and that the right sensor mount  230  and/or left sensor mount  240  are positioned over the shoulders of the tire casing. The distance measurement by the distance sensor  250  can ensure proper set up of the belt detection apparatus  200  prior to a buffing process. In some implementations, if the distance measured by the distance sensor  250  is not within a predetermined error range of a target width, then the buffing process may be aborted. The target width can be based on a tire casing width dimension, either manually entered or determined using a look-up table. 
     The frame  210  shown in  FIGS.  2 - 3    includes four wheels  212  that contact a crown surface of a tire casing during the buffing process. As the wheels  212  have a predetermined diameter and position relative to the frame  210 , the distance between the crown surface of the tire casing and each of the sensors  222 ,  232 ,  242  is known. In the implementation shown, two wheels  212  are rotatably mounted with the center sensor mount  220  and a single wheel  212  is mounted to each of the right sensor mount  230  and left sensor mount  240 . The set of wheels  212  for the center sensor mount  220  are fixed relative to the frame  210  while the wheels  212  for the right sensor mount  230  and left sensor mount  240  are fixed to each of the right sensor mount  230  and left sensor mount  240  and are adjustable along the horizontal axis with the right sensor mount  230  and left sensor mount  240 . As each wheel  212  is positioned with a contact point with the tire casing at a known distance relative to the corresponding center, left, and right sensor mounts,  220 ,  230 ,  240 , the distance between each sensor  222 ,  232 ,  242  and each wheel  212  for the corresponding center, left, and right sensor mounts,  220 ,  230 ,  240  is known as is a distance from the contact point of a corresponding wheel to a corresponding each sensor  222 ,  232 ,  242 . The distance for a detected one or more belts by each sensor  222 ,  232 ,  242  can be calculated by subtracting the vertical distance between the contact point of the corresponding wheel  212  from a measured distance by a corresponding sensor  222 ,  232 ,  242 . In some embodiments, distance for a detected one or more belts by each sensor  222 ,  232 ,  242  can be calculated by subtracting the vertical distance between the contact point of the crown of the tire from a measured distance by a corresponding sensor  222 ,  232 ,  242   
     In some implementations, the belt detection apparatus  200  can be selectively lowered to an active position and raised to a stored position relative to a tire casing using a pneumatic cylinder. The selective lowering of the belt detection apparatus  200  can be performed automatically when a buffing process is initiated. In some implementations, the raising of the belt detection apparatus  200  can be performed automatically when a pre-determined depth of tire casing above the one or more belts is met based on the measurements from the sensors  222 ,  232 ,  242 . In some instances, the belt detection apparatus  200  can be raised at any time the buffing process is paused. 
     Referring to  FIG.  5   , a method  300  of buffing a tire casing using a buffer (e.g., the apparatus  100 ) with a controller (e.g., the controller  104 ) is provided. At  302 , a database (e.g., the database of the controller  104 ) maintains instructions carried out by the controller, including instructions for buffing procedures. The database also maintains information relating to a plurality of buffing parameter profiles (e.g., desired crown and shoulder characteristics, minimum belt depths, etc.) corresponding to a plurality of tire casing sizes and specifications. 
     At  304 , the buffer is operated to buff a mounted tire casing (e.g., the tire casing  112 ) pursuant to parameters for a buffer parameter profile maintained the database. In operation during a buffing process, the tire casing  112  is engaged to the rasp of the rasp pedestal  102 . The tire hub assembly may be configured to rotate the tire casing  112  as the rasp removes casing material from the outer circumference of the tire casing  112 . The tire casing may be buffed to position a set of belts (e.g., the belts  114 ) at a predetermined depth beneath the crown surface of the tire casing. A belt detection apparatus (e.g., the belt detection apparatus  200 ) measures the depth of the belts at  306 , which may be performed on a continuous or periodic basis (e.g., once for every rotation of the tire casing). The belt detection apparatus  200  provides the controller  104  with data corresponding to one or more depths of the one or more belts  114  within the tire casing  112  from the sensors  222 ,  232 ,  242 . As such, the controller  104  may continuously or periodically (e.g., once per rotation of the tire casing  112 ) monitor the amount of tire casing material remaining using the sensors  222 ,  232 ,  242  during the buffing process. The controller  104  may check an amount of remaining tire casing material with the belt depth provided by the belt detection apparatus  200  and adjust the cut depth of the buffer accordingly. 
     In response to the measurements and calculations with respect to the tire casing  112 , the controller  104  may adjust the buffing process, at  308 , to prevent over or under-buffing of the tire casing  112  (e.g., adjusting a buffer cut depth). In some arrangements, the controller  104  may be configured to halt the operation of the rasp if the belt depth meets or falls below a predetermined minimum belt depth (e.g., as indicated in a corresponding casing profile in the database). For example, the controller  104  may determine that the one or more belts  114  are 4/32″ below the surface of the tire casing  112 , and the current cut depth of the buffer is set for 3/32″ per pass. Where the target belt depth is 2/32″ below the crown surface of the tire casing  112 , the controller  104  may reduce the cut depth of the buffer from 3/32″ to 2/32″, and as such, the next buffing pass will yield a belt depth of 2/32″. 
     When the buffing process  300  is finished, the apparatus can disengage the rasp and/or the belt detection apparatus  200  to be returned to a stored position such that the buffed tire casing can be removed from the apparatus. 
     A tire buffing machine can include a controller enabling the tire buffing machine to buff a casing while monitoring the location of a belt package disposed therein. The controller includes instructions stored on non-transient data media causing the controller to perform operations of maintaining a database containing a plurality of casing profiles, each casing profile including corresponding buffing parameters; operating a buffer to buff the casing in accordance with buffing parameters associated with one of the plurality of casing profiles; determining a first belt depth at a first lateral position within a tire casing and a second belt depth at a second lateral position within the tire casing using a belt detection apparatus having two or more sensors configured to detect the first belt depth and the second belt depth within the tire casing; and adjusting the operation of the buffer based on the first belt depth or the second belt depth. The belt detection apparatus can include one or more wheels configured to ride on an exterior surface of the tire casing. The belt detection apparatus can include a distance sensor. A first sensor of the two or more sensors can be mounted to a left sensor mount, a second sensor of the two or more sensors can be mounted to a right sensor mount, and the distance sensor can be configured to measure a distance between the left sensor mount and the right sensor mount. The belt detection apparatus can include a center sensor and a center sensor mount. The two or more sensors can be inductive sensors. The controller can adjust a cut depth of the buffer based on the first belt depth or the second belt depth. The controller can be configured to stop the operation of the buffer if the first belt depth or the second belt depth reaches a predetermined minimum depth specified in the one of the plurality of casing profiles. 
     A method of manufacturing a retreaded tire casing may include maintaining, in a database, a plurality of casing profiles, each casing profile including corresponding buffing parameters; operating a buffer to buff the casing in accordance with buffing parameters in one of the plurality of casing profiles; determining, by a controller, a first belt depth at a first lateral position within a tire casing and a second belt depth at a second lateral position within the tire casing using a belt detection apparatus having two or more sensors configured to detect the first belt depth and the second belt depth within the tire casing; and adjusting, by the controller, the operation of the buffer based on the first belt depth or the second belt depth. The belt detection apparatus can include one or more wheels configured to ride on an exterior surface of the tire casing. The belt detection apparatus can include a distance sensor. The first sensor of the two or more sensors can be mounted to a left sensor mount, a second sensor of the two or more sensors can be mounted to a right sensor mount, and the distance sensor can be configured to measure a distance between the left sensor mount and the right sensor mount. The belt detection apparatus can include a center sensor and a center sensor mount. The two or more sensors can be inductive sensors. The controller can be configured to stop the operation of the buffer if the first belt depth or the second belt depth reaches a predetermined minimum depth specified in the one of the plurality of casing profiles. 
     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise indicated. 
     While the invention is described herein in connection with certain preferred embodiments, there is no intent to limit the present invention to those embodiments. On the contrary, it is recognized that various changes and modifications to the described embodiments will be apparent to those skilled in the art upon reading the foregoing description, and that such changes and modifications may be made without departing from the spirit and scope of the present invention. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of the invention. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.