Abstract:
A programmable wheel and tire assembly machine and method of assembly is disclosed which compensates for different wheel and tire combinations, as well as dynamically manipulates the present arms during the mounting process. An upper present arm is supported in a manner to provide at least two axes of movement, the upper present arms capable of independent manipulation along/about each axis. A lower present arm is supported in a manner to provide at least one axis of movement, the lower present arm capable of manipulation in a horizontal plane. Wheel and tire data is collected and used to generate a mounting protocol for individual tire &amp; wheel combination. Continuous position feedback of the present arms may be employed to further control movement throughout the mounting process.

Description:
FIELD 
       [0001]    The present disclosure relates to wheel and tire assembly and more particularly to a programmable machine and method for assembling a wheel and tire. 
       BACKGROUND 
       [0002]    This section provides background information related to the present disclosure which may not constitute prior art. 
         [0003]    To properly mount a tire to a wheel, the tire has to be presented and held into place so that a portion of the lower bead of the tire is pushed against the safety bead of the wheel when the starting the mounting process. This condition needs to be maintained through the mounting process. A single bead mounting process requires two revolutions by the mounting head with each revolution mounting one tire bead to the wheel. A dual bead mounting process is completed in a single revolution with both tire beads being mounted to the wheel simultaneously during this revolution. 
         [0004]    The process of presenting the tire to the wheel with certain machinery is well known in the art. However, this process has been completed using a fixed location methodology in which all of the motions are single stroke motions with hard stopping positions. This fixed location methodology has recently encountered difficulties in tire mounting due to the introduction of new tire technology and the continuous decrease of tire aspect ratios. Thus, there is a need to provide a method and machine capable of using an adjustable location methodology for dynamic control of the present arms during the mounting process. 
       SUMMARY 
       [0005]    This section provides a general summary of the present disclosure, but is not intended to be a comprehensive disclosure of the full scope of the subject matter or all of its features. 
         [0006]    A programmable wheel and tire assembly machine and method of assembly is disclosed which is able to compensate for different wheel and tire combinations as well as to dynamically manipulate upper and lower stuffer assemblies during the mounting process. Currently these developments have yielded two methodologies. In a first embodiment, the upper stuffer assembly includes an upper present arm carried on an articulated robotic arm such that it provides six controlled axes to manipulate the upper present arm. In a second embodiment, the upper stuffer assembly includes an upper present arm carried on a drive unit having two servo-controlled axes with each axis able to independently manipulate the upper present arm. In addition, the lower stuffer assembly includes a pair of lower present arms carried on a drive unit, each arm having a single servo-controlled axis to manipulate the lower present arm in a horizontal plane and provide dynamic tire holding and positioning capabilities. Unlike conventional upper and lower stuffer assemblies, this technology is able to continuously manipulate to the upper and lower present arms to various programmed positions during the mounting process. Using a robotic arm and/or servo-controlled drivers allow for continuous position and/or force feedback of the present arm movement throughout the mounting process. In addition, wheel and tire data can be stored in memory and associated with the desired mounting protocol. In this way, the mounting protocol for each individual tire &amp; wheel combination can be quickly and accurately recalled for programming the machine. 
         [0007]    In practice, a programmable machine in accordance with the above-described developments includes a bed for supporting a wheel, a clamping mechanism positionable with respect to the bed for clamping the wheel onto the bed, a lower present arm positionable from a home position to a bead mount position with respect to the bed for locating and holding a tire relative to the wheel, an upper present arm positionable from a home position to a tire hold position with respect to the bed for locating and holding the tire relative to the wheel, and a mounting head moveable along a tire mounting path with respect to the bed for assembling the tire on the wheel. A machine controller is operable to recall a mounting protocol from a stored memory location based on wheel and tire data. The machine controller communicates instructions to the clamping unit, the lower stuffer assembly, the upper stuffer assembly and the mounting head, based on the mounting protocol for positioning and manipulating these components during the mounting process. 
         [0008]    In practice, a method of assembling a wheel and tire in accordance with the above-described developments includes acquiring data for a wheel and tire combination and recalling a mounting protocol based on the data. A wheel is transferred into a mounting station and clamped into position. A tire is transferred into the mounting station and a lower present arm is positioned to locate and hold the tire relative to the wheel. An upper present arm is positioned to a tire hold down position to locate and hold the tire relative to the wheel. A mounting head is manipulated along a tire mounting path based on the mounting protocol for assembling the tire on the wheel. The lower and upper present arms are also manipulated based on the mounting protocol while the mounting head is manipulated along the tire mounting path to facilitate assembly of the tire onto the wheel. 
         [0009]    Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0010]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0011]      FIG. 1  illustrates a programmable machine for tire and wheel assembly; 
           [0012]      FIG. 2  illustrates a schematic cross-section of the clamping unit and lower stuffer assembly shown in  FIG. 1 ; 
           [0013]      FIG. 3  illustrates a schematic cross-section of the mounting head and upper stuffer assembly shown in  FIG. 1 ; 
           [0014]      FIG. 4  illustrates a schematic cross-section of an alternate embodiment to the upper stuffer assembly shown in  FIG. 1 ; and 
           [0015]      FIG. 5  is a flow-chart representing an automated method for tire and wheel assembly. 
       
    
    
       [0016]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0017]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0018]    Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope of this disclosure to those who are skilled in the art. Specific details may be set forth to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known structures, and well-known technologies are not described in detail. 
         [0019]    The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of recited structure(s) or step(s); for example, the stated features, integers, steps, operations, groups elements, and/or components, but do not preclude the presence or addition of additional structure(s) or step(s) thereof. The methods, steps, processes, and operations described herein are not to be construed as necessarily requiring performance in the stated or any particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional, alternative or equivalent steps may be employed. 
         [0020]    When structure is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” other structure, it may be directly or indirectly (i.e., via intervening structure) on, engaged, connected or coupled to the other structure. In contrast, when structure is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” the other structure, there may be no intervening structure present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent”). As used herein, the term “and/or” includes any and all combinations of one or more of the associated referenced items. 
         [0021]    Terms of degree (e.g., first, second, third) which are used herein to describe various structure or steps are not intended to be limiting. These terms are used to distinguish one structure or step from other structure or steps, and do not imply a sequence or order unless clearly indicated by the context of their usage. Thus, a first structure or step similarly may be termed a second structure or step without departing from the teachings of the example embodiments. Likewise, spatially relative terms (e.g., “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper”) which are used herein to describe the relative special relationship of one structure or step to other structure or step(s) may encompass orientations of the device or its operation that are different than depicted in the figures. For example, if a figure is turned over, structure described as “below” or “beneath” other structure would then be oriented “above” the other structure without materially affecting its special relationship or operation. The structure may be otherwise oriented (e.g. rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
         [0022]    With reference now to  FIG. 1 , a programmable tire presenter  10  in accordance with present disclosure is illustrated. The tire presenter  10  defines a mounting station  12  having a fixture  14 , a clamping unit  16 , a lower stuffer assembly  18 , a mounting head  20  and an upper stuffer assembly  22 . The upper stuffer assembly  22  includes a multi-axis robot  24  for manipulating an upper present arm  26  (as best seen in  FIG. 2 ). A programmable controller  28  is in communication with the clamping unit  16 , the lower and upper stuffer assemblies  18 ,  22  and the mounting head  20  for providing operational control over the movement of these components. The mounting station  12  would typically include material handling machinery (not shown) located adjacent the mounting station  12  for transporting wheels W and tires T into and out of the tire presenter  10 . Alternately, the wheels W and tires T could be manually transported to and from the tire presenter  10 . 
         [0023]    With reference now to  FIGS. 1 and 2 , the fixture  14  includes a pedestal  30  supporting a bed  32  defining a fixed working surface. The clamping unit  16  is generally supported beneath the bed  32  and has a drive unit  34  coupled to a set of slide blocks  36 . A clamping pawl  38  formed on the top of the slide block  36  extends through the bed  32  above the working surface. The drive unit  34  may take any conventional form and is operable to move the slide blocks  36  laterally inward from an unclamped position to a clamped position. With the slide blocks  36  in the clamped position, the clamping pawls  38  engage a portion of the wheel W, preferably the wheel rim, for securing the wheel W to the bed  32 . In the present embodiment, the drive unit  34  has a motor-driven spur gear with a pair of gear racks, one located on each side of the spur gear. The slide blocks  36  are coupled to the racks so that rotation of the spur gear laterally moves the clamping pawls  38 . While  FIG. 2  shows a single clamping pawl  38  engaging the wheel W, one skilled in the art will understand that the clamping unit  16  employs multiple clamping pawls arranged in a spaced relation about the wheel. 
         [0024]    The lower stuffer assembly  18  is also generally supported beneath the bed  32  and has a drive unit  40  coupled to the lower present arms  42  that extend through the bed  32  above the working surface. As presently preferred, a pair of lower present arms  42  are arranged in spaced relation along the Z axis and operate independent of each other. The lower present arms  42  is angularly oriented from the vertical (Y) axis in the range of 15°-25° which generally corresponds to the angular orientation of a tread surface of the tire T (as best seen in  FIGS. 3 and 4 ). Each lower present arm  42  is horizontally manipulated during the tire mounting process for positioning and properly orienting the tire T with respect to the wheel W. For example, the lower present arms  42  are first positioned to hold the tire so that it does not rotate relative to the wheel. Next, the lower present arms  42  are manipulated to push the tire bead into the safety bead of the wheel W. In the present embodiment, the drive unit  40  for each lower present arm  42  is a single axis servo-driven ball screw cylinder which is coupled to the lower present arm  42  and operable to manipulate the lower present arm  42  through a continuous range of positions in a lateral direction (i.e., in a direction parallel to the X axis). In addition, using servo-controlled cylinders allows for continuous position and force feedback control of the lower present arm during the wheel and tire mounting process. While  FIG. 2  shows a pair of lower present arm  42  for positioning the tire T, one skilled in the art will understand that the number of lower present arms employed in the lower stuffer assembly  18  may vary. 
         [0025]    With reference now to  FIGS. 1 and 3 , the fixture  14  includes a vertical weldment  44  having a carriage assembly  46  which supports the mounting head  20  generally above the bed  32 . The carriage assembly  46  is slidably supported on the vertical weldment  44  for vertical positioning the mounting head  20  movement with respect to the bed  32 . The mounting head  20  includes a rotary driver  48  such as a servo-motor having an output shaft  50  coupled to a bead roller assembly  52 . Operation of the rotary driver  48  causes the bead roller assembly  52  to rotate about a vertical motor axis  54 . In particular, the vertical motor axis  54  is aligned with the central axis of the wheel W as best seen in  FIG. 3 . The rotary driver  48  may incorporate a transmission or other gear reduction mechanism for adjusting the speed and torque of the bead roller assembly  52 . 
         [0026]    The bead roller assembly  52  includes a positioner  56  coupled to an end of the output shaft  50 , an arm  58  extending downwardly from the positioner  56 , and a bead roller  60  supported on an end of the arm  58  opposite the positioner  56 . The positioner  56  slidably supports the arm  58  and for radially positioning the bead roller  60  with respect to the vertical motor axis  54 . As presently preferred the positioner  56  is a slide mechanism that can be positioned radially into a desired location. A braking unit  62  is used to fix the positioner  56  in the desired location. Alternately, the positioner could employ a drive unit such as a servo-controlled ball screw cylinder for radially positioning and fixing the arm  58  and bead roller  60 . The bead roller  60  is attached to a free end  62  of the arm  58  so that it may rotate freely on the arm  58 . 
         [0027]    The upper present arm  26  of upper stuffer assembly  22  is coupled to the end of a robotic arm  64  and operable to manipulate the upper present arm  26  through a continuous range of positions within the three-dimensional space around the mounting station  12 . In addition, the robotic arm  64  allows for continuous position and force feedback control of the upper present arm  26  during the wheel and tire mounting process. The upper present arm  26  includes an end effector  66  secured to the faceplate of the robotic arm  64  and a tire hold down  68  attached to a free end of the end effector  66 . The nose  70  of the tire hold down  68  is configured to engage the side wall of the tire T for locating and holding the tire T during assembly. For example, the upper present arm  26  is manipulated to push the top bead down into the drop center (mid-region) of the wheel W. As presently preferred, the tire hold down  68  includes a spring biased slide to compliantly support the nose  70  on the end effector  66 . When viewed from above (plan view looking down the Y axis), the nose  70  has an arcuate shape that generally corresponds to the range of wheel radii to be mounted in the tire presenter  10 . 
         [0028]    A tapered pin  72  is also attached to the free end  68  of end effector and extends generally away from the tire hold down  68 . The tapered pin  72  may be inserted into a hole  74  formed in the positioner  56  so that the robotic arm  64  may be used for radially locating the positioner  56 . With reference now to  FIG. 4 , an upper stuffer assembly  200  which represents an alternate embodiment of the upper stuffer assembly  22  is illustrated. Upper stuffer assembly  200  employs a set of servo-driven ball screw cylinders  202 ,  204  to manipulate the present arm  206  along two axes—the vertical axis (Y) and the horizontal axis (X). The upper stuffer assembly  200  is attached to the carriage  44  adjacent the mounting head  20  and moves concurrently in a vertical direction on the carriage  44  with the mounting head  20 . The cylinder  202  is oriented in the vertical (Y) direction and has a rod  208  extending downwardly. The free end of the rod  208  is coupled to the cylinder  204  which is oriented in the horizontal (X) direction and has a rod  210  extending laterally. The upper present arm  206  includes an end effector  212  secured to the free end of the rod  210  and a tire hold down  214  attached to a free end of the end effector  212 . Similar to the nose  70 , nose  216  configured to engage the side wall of the tire T for locating and holding the tire T during assembly. When viewed from above (plan view looking down the Y axis), the nose  216  has an arcuate shape that generally corresponds to a range of wheel radii to be mounted in the tire presenter  10 . 
         [0029]    The upper present arm  206  is manipulated during the tire mounting process for properly positioning the upper tire bead into the drop center of the wheel W and further restricting movement of the tire T with respect to the wheel W. Cylinders  202 ,  204  are coupled to the upper present arm  206  and operable to manipulate the upper present arm  206  through a continuous range of positions within a plane parallel to the plane defined by the X-Y axes. In addition, using servo-controlled cylinders allows for continuous position feedback control of the upper present arm  206  during the wheel and tire mounting process. 
         [0030]    With reference now to the flowchart illustrated in  FIG. 5 , a wheel and tire assembly process in accordance with the present disclosure will now be described. Except as noted, the following description of the wheel and tire assembly process is made with reference to the embodiments illustrated in  FIGS. 1-3 . 
         [0031]    Upon initiation the tire presenter  10  is in an idle state with the clamping pawls  38  of the clamping unit  16  in an open, unclamped position. The mounting head  20  and the lower and upper present arms  18 ,  26  are located away from the bed  32  in a home position. In the idle state, the tire presenter  10  is ready to receive a wheel W and tire T. Next wheel and tire data specifying the characteristics of the wheel W and tire T combination to be assembled is acquired and communicated to the controller  28 . Any suitable means of data acquisition may be used, for example, data scan technology which reads wheel and tire data directly from the wheel W and tire T or from manufacturing labels on the wheel W and tire, or from data communicated from a factory information system, or direct input of wheel and tire data by an operator. 
         [0032]    The controller  28  uses the wheel and tire data to generate a mounting protocol which includes specific instructions for positioning and manipulating the components of the tire presenter  10  during the assembly process. The mounting protocol may be generated by the controller  28  through a data look-up function in which identifications for various wheels W and tires T are cross-referenced in a look-up table with a specific pre-defined mounting protocol stored in memory. The look-up function uses particular wheel and tire data to recall a mounting protocol for that particular combination of wheel W and tire T. The mounting protocol may also be generated by the controller through a data processing routine if the wheel and tire data provides adequate information such that the controller  28  can compute a suitable mounting protocol. In this sense, the mounting protocol includes a set of instructions used to program the tire presenter  10  and provide an automated method for tire and wheel assembly. 
         [0033]    A wheel W or a wheel W and tire T combination is transferred into the mounting station  12  and generally located on the bed  32 . Once generally located, the clamping unit  16  positions the clamping pawls  38  from the unclamped position to a clamped position. In the clamped position, the clamping pawls  38  secure the wheel W in a fixed and predetermined location with respect to the mounting station  12 . The mounting protocol may instruct the clamping unit to perform this function. If not already loaded, a tire T is transferred into the mounting station  12  and generally located on the wheel W. Once generally located, the lower stuffer assembly  18  to hold the tire T and position the lower present arm  42  from the home position to a bead mount position. In the bead mount position, the lower present arms  42  locate the tire T in a predetermined location with respect to the mounting station  12  such that the lower bead engages the safety bead on the wheel W. The mounting protocol may instruct the lower stuffer assembly  18  to perform this function. 
         [0034]    With particular reference to  FIGS. 1 and 3 , once the wheel W and tire T are positioned at a known location in the mounting station  12 , the robotic arm  64  positions the upper present arms  26  from the home position to a tire hold down position. In the tire hold down position, the nose  70  of the tire hold down  68  engages a sidewall of the tire T to move the upper bead into the drop center of the wheel, and further restricts movement of the tire T. The mounting protocol may instruct the upper stuffer assembly  22  to perform this function. With the upper present arms  26  in the tier hold down position, the mounting protocol instructs the carriage  46  and mounting head  20  to position the bead roller  60  into engagement with the tire T. Once so engaged, the mounting protocol instructs the rotary driver  48  and the radial positioner  56  to manipulate the arm  58  and the bead roller  60  about the circumference of the wheel W, thereby moving the bead of the tire T into position between the rims of the wheel W. 
         [0035]    Simultaneous with the manipulation of the bead roller  60 , the mounting protocol may instruct the upper present arm  26  to manipulate the tire hold down  68  away from the tire hold down position along a tire mounting path. For example, the upper present arm  26  may be manipulated to move the tire hold down  68  vertically (up or down) parallel to the central axis of the wheel W. Similarly, the upper present arm  26  may be manipulated in a plane parallel to the bed  32  (i.e., parallel to a plane defined by the X-Z axes). Movement in the X-Z plane allows the tire hold down  68  to be positioned radially (inward or outward) of the central axis of the wheel W and/or to be positioned circumferentially about the rim of the wheel W. As such, the mounting protocol can instruct the upper present arm  26  to move through a continuous range of motion in three dimensions during the tire mounting process. 
         [0036]    With particular reference to the embodiment illustrated in  FIG. 4 , once the wheel W and tire T are positioned at a known location in the mounting station  12 , the upper stuffer assembly  200 , and in particular the drive cylinders  202 ,  204  positions the upper present arms  206  from the home position to a tire hold down position. In the tire hold down position, the nose  216  of the tire hold down  214  engages a sidewall of the tire T to position the upper bead into the drop center of the wheel W, and further restricts movement of the tire T. The mounting protocol may instruct the upper stuffer assembly  22  to perform this function. With the upper present arm  206  in the tier hold down position, the mounting protocol instructs the carriage  46  and mounting head  20  to position the bead roller  60  into engagement with the tire T. Once so engaged, the mounting protocol instructs the rotary driver  48  and the radial positioner  56  to manipulate the arm  58  and the bead roller  60  about the circumference of the wheel W, thereby moving the bead of the tire into position between the rims of the wheel W. 
         [0037]    Simultaneous with the manipulation of the bead roller  60 , the mounting protocol may instruct the upper stuffer assembly  200  to manipulate the upper present arm  206  away from the tire hold down position along a tire mounting path. For example, the upper present arm  206  may be manipulated to move the tire hold down  68  parallel to the Z axis (i.e. vertically up or down) or parallel to the X axis (i.e., horizontally left or right) such that the nose  208  can to be positioned radially (inward or outward) of the central axis of the wheel W. As such, the mounting protocol can instruct the upper present arm  206  to move through a continuous range of motion in two dimensions during the tire mounting process. 
         [0038]    Returning to the general assembly method, the mounting protocol may also instruct the lower stuffer assembly  18  to manipulate the lower present arm  42  away from the bead mount position along a tire mounting path simultaneous with the manipulation of the bead roller  60 . For example, the lower present arm  42  may be manipulated to move parallel to the X axis (i.e., horizontally left or right) and thus radially (inward or outward) of the central axis of the wheel W. As such, the mounting protocol can instruct the lower present arm  26  to move through a continuous range of motion in one dimension during the tire mounting process. 
         [0039]    Simultaneous manipulation of the lower stuffer assembly  18  and/or the upper stuffer assembly  22  during the tire mounting process eliminates the fixed stop constraints of conventional system and enables continuous adjustment for the position of the wheels W and tires T and improved holding capabilities. Moreover, the use of a robotic arm and servo-controlled cylinders enables position and/or force feedback control to further improve the accuracy of the instructions provided by the mounting protocol and to increase efficiency of the mounting process. 
         [0040]    The mounting protocol may instruct the mounting head  20  to make a single revolution around the circumference of the wheel W during a dual bead mounting process such that both beads of a tire T are mounted onto the wheel W to form a tire and wheel assembly. Alternately, the mounting protocol may instruct the mounting head  20  to make two revolutions around the circumference of the wheel W during a single bead mounting process such that one bead of the tire T is mounted onto the wheel W with each pass to form the tire and wheel assembly. With the tire and wheel assembly complete, the mounting protocol instructs the mounting head  20  and the lower and upper stuffer assemblies  18 ,  22  to be positioned back to the home position. The mounting protocol then instructs the clamping unit  16  to move the clamping pawls  38  from the clamped position to the unclamped position to release the tire and wheel assembly. The tire and wheel assembly may be transferred out of the mounting station  12  by any suitable means as previously described. The tire presenter  10  is once again in an idle state and prepared to repeat the assembly process. 
         [0041]    An assembly process in accordance with the present disclosure may acquire wheel and tire data at any point in time prior to initiation of the assembly process. In other words, the wheel and tire data need not be acquired before the wheel W and/or tire T is transported to the mounting station  12 , but may be captured once the mounting station is loaded. Similarly, the assembly process does not require that wheel and tire data be acquired for each and every assembly sequence, but may be acquired in a batch manner such that wheel and tire data is acquired once for a batch or lot of assemblies when an identical combination of wheels W and tires T is involved. 
         [0042]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.