Abstract:
A tire changing machine comprises a chassis and a rotatable turntable configured to retain a wheel rim. The machine further includes a tower carrying a mount/demount head movable toward and away from the wheel rim. A saddle for retaining a tire in a generally upright configuration is also provided. In addition, the machines includes an ovalation mechanism operative to press on a tread portion of a tire mounted in the saddle so as to ovalate the tire.

Description:
PRIORITY CLAIM 
   This application claims the benefit of provisional application Ser. No. 60/755,660, filed Dec. 30, 2005, which is relied upon and incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to tire changers and processes used in the changing of tires. More particularly, the present invention relates to a tire changing machine incorporating features to assist an operator in changing a tire with a liner such as those used in NASCAR vehicles. 
   Those of skill in the art of designing and manufacturing equipment used to change tires mounted on the rims of cars, light trucks, and other vehicles will appreciate that many prior art tire changing machines exist. For example, a rim holding tire changer is disclosed in U.S. Pat. No. 6,182,736 to Cunningham et al., the disclosure of which is incorporated herein by reference. 
   The typical tire-changing procedure involves the following steps: (1) loosening the seal between the tire&#39;s bead and the rim, (2) placing the tire-rim assembly on the tire changer, (3) securing the rim to the tire changer, (4) removing the tire from the rim using a mount/dismount head, (5) placing a new tire over the rim, (6) mounting the tire on the rim by using the mount/dismount head to force the bead over the rim, and (7) filling the air chamber of the tire with air to inflate the new tire. 
   Changing a NASCAR-specific tire involves more steps than changing a typical passenger vehicle tire due to the presence of a tire liner within the tire. Therefore, in addition to the steps recited above, changing a NASCAR tire includes steps associated with removing and installing the tire liner. Typically, the NASCAR tire is ovalated (i.e., made oval shaped) by the application of force to the tire such that the liner may be more easily removed/inserted. Because the sidewalls of NASCAR tires are typically quite stiff, the application of a relatively large amount of force may be necessary to ovalate the tire. 
   SUMMARY OF THE INVENTION 
   The present invention recognizes and addresses various considerations of prior art constructions and methods. 
   According to one aspect, the present invention provides a tire changing machine comprising a chassis and a rotatable turntable configured to retain a wheel rim. The machine further includes a tower carrying a mount/demount head movable toward and away from the wheel rim. A saddle for retaining a tire in a generally upright configuration is also provided. In addition, the machines includes an ovalation mechanism operative to press on a tread portion of a tire mounted in the saddle so as to ovalate the tire. 
   Preferably, the ovalation mechanism may include a helper arm assembly having an articulated helper arm. In such embodiments, a fluid actuated cylinder may be located at a distal end of the articulated helper arm. A contact block may be located at a distal end of the cylinder&#39;s piston shaft. An arcuate tire bar may be connected to the contact block. 
   In some cases, it may be desirable to provide wheels located adjacent a back of the chassis to facilitate movement of the tire changing machine. The saddle in such embodiments may be attached to the chassis at a front thereof to be used as a handle in lifting the front of the chassis. In addition, the saddle may be reversible between a tire holding and a handle position. The saddle may also define a notch for receipt of a tip portion of a pry bar to provide a fulcrum for removal of a tire liner. 
   According to another aspect, the present invention may provide a tire changing machine comprising a chassis and a rotatable turntable configured a retain a wheel rim. The machine further comprises a tower carrying a mount/demount head movable toward and away from the wheel rim. A horizontal roller assembly having at least one roller mounted at the distal end of an elongate bar is also provided. The elongate bar is slidable in a horizontal receiver which is vertically movable. In some exemplary embodiments, a rotational axis of the roller may be laterally offset from an axis of the elongate bar. 
   Other aspects of the present invention are provided by a tire changing machine comprising a chassis and a rotatable turntable configured a retain a wheel rim. The machine further includes a tower carrying a mount/demount head movable toward and away from the wheel rim. Also provided are first and second separate gas supplies with respective first and second inflation hoses permitting simultaneous inflation of a tire and an inner liner thereof. Preferably, the first and second separate gas supplies may function to supply different gases. In such embodiments, one of the gases may be air. 
   Other objects, features and aspects of the present invention are discussed in greater detail below. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, incorporated in and constituting part of this specification, illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
       FIG. 1  is a perspective view of a tire changing machine in accordance with an embodiment of the present invention; 
       FIG. 2  is a front view of the tire changing machine of  FIG. 1 ; 
       FIG. 3  is a side view of the tire changing machine of  FIG. 1 ; 
       FIG. 4  is an operator side view (opposite the side of  FIG. 3 ) of the tire changing machine in  FIG. 1 ; 
       FIG. 5  is a rear view of the tire changing machine in  FIG. 1 ; 
       FIG. 6  is a perspective view of the tire changing machine of  FIG. 1  with a NASCAR-type tire carried by the saddle and rim mounted on the turntable; 
       FIG. 7  is a side view of the tire changing machine in  FIG. 1  with the tire and rim as in  FIG. 6 ; 
       FIG. 8  is a front view of the tire changing machine shown in  FIG. 1  with the tire and rim as in  FIG. 6 ; 
       FIG. 9  is a top view of the tire changing machine shown in  FIG. 1 ; 
       FIG. 10  shows the arcuate tire bar attached to the contact block of the helper arm assembly; 
       FIG. 11  illustrates one preferred method of removing the inner lining of a NASCAR-type tire in accordance with the present invention; 
       FIG. 12  shows the mount/demount head adjacent the rim&#39;s top edge; and 
       FIG. 13  shows the use of an elongate lift tool to pry the tire&#39;s top bead over the mount/demount head. 
   

   Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Reference will now be made in detail to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying 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 modifications and variations can be made in the present invention without departing from the scope and spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations. 
   Referring first to  FIGS. 1 through 5 , several views of a tire changer  10  in accordance with the present invention are shown. Although tire changer  10  is designed for NASCAR-type tires, it also may assist operators in changing any type of tire, especially tires that require tire liners. As such, tire changer  10  could be used to change PAX style tires, which have a liner in the form of an annular support member. 
   Tire changer  10  includes a chassis  12  having a first side  14 , a second side  16 , a front  18 , and a back  20 . In this embodiment, a turntable in the form of a chuck  22  extends through a chassis top  23  and is threaded to accept a centering cone  24  to attach a rim to the chuck. One skilled in the art will appreciate, however, that other types of turntables may be used depending on the needs of a particular application. For example, embodiments are contemplated using a tabletop having rim engaging clamps that move radially. 
   A removable saddle  25  includes two prongs that are received in two matching holes in front  18 . An additional pin (not shown) may be used to further secure saddle  25  to chassis  12 . Saddle  25  is shaped and positioned to hold a NASCAR-type tire in this embodiment. Optionally, saddle  25  may be removed from the holes in front  18 , rotated around and inserted into additional holes in chassis top  23 . In this second configuration (shown in phantom lines in  FIG. 1 ), saddle  25  may be used as a handle  27  by which an operator might lift the front of tire changer  10  and move it from from location to location (or to reduce the envelope size for storing while transporting the machine from one racetrack to another). 
   Also attached to chassis  12  are a series of implements including helper arm assembly  26 , mount/dismount assembly  28 , and horizontal roller system  30 . A detailed description of the use of a helper arm similar to that of assembly  26  can be found in U.S. Pat. No. 6,182,736, incorporated herein by reference. 
   In the embodiment shown in the Figures, helper arm assembly  26  is attached to a central tower  32 . The helper arm of assembly  26  has first and second arm segments  34  and  36  pivotally connected at an intermediate location for articulation with respect to one another. A proximal end of arm segment  34  is pivotally connected to tower  32 . The distal end of arm segment  36  carries a fluid actuated cylinder  44  (in this case a pneumatic cylinder) having a piston shaft  38 . A contact block  40  is affixed to the end of cylinder shaft  38 . An air line  42  supplies air to cylinder  44 , the supply of which is controlled by lever  46 . Contact block  40  thus moves up and down with vertical movement of shaft  38 . 
   Mount/dismount assembly  28  is a “floating” system in the preferred embodiment, although other types of arms known by those in the art could be utilized. Mount/dismount assembly  28  includes arm  48  hinged to central tower  32  and arm  50  hinged to arm  48 . As can be seen, arms  48  and  50  are hinged to rotate in the vertical plane. A mount/dismount head  52  is provided at the distal end of arm  50 . 
   Horizontal roller system  30  includes an upper offset roller  54  and a lower offset roller  56 . Rollers  54  and  56  are attached to the end of elongate bars  58  and  60 , respectively. Receivers  62  and  64 , attached to a vertically movable body  66 , slidably receive the respective bars. Toggling lever  68  causes body  66  (and the rollers attached thereto) to up and down (preferably by power of a pneumatic cylinder). Cam locks  69  affixed to the receivers enable the user to lock shafts  58  and  60  in a desired axial position. 
   In addition to mechanically assisting a user in mounting and dismounting a tire and tire liner, machine  10  also may accommodate dual gas supplies such that the user may inflate the tire and the tire liner simultaneously and/or with different gasses. At the top of tower  32  are twin inflation gauges  70  and  72 , one for each of the gas supplies. Preferably, one of the dual gas supplies is attached to an accumulator that feeds both the pneumatics and one of the inflation hoses, while the other gas supply is attached to an accumulator that feeds only a second inflation hose. The inflation hoses may be conveniently mounted to tower  32 , or situated at another suitable location. 
   At the bottom of chassis  12 , a first pedal  74 , a second pedal  76 , and a third pedal  78  are provided. A can be seen, the pedals are located on a first side  14  of chassis  12  in the illustrated embodiment. This placement is ergonomic because it advantageously allows the operator to stand in one place while manipulating the various implements of the machine. 
   First pedal  74  and second pedal  76  control the flow of gas through the respective inflation hoses. That is, depressing either of the pedals will allow the passage of gas, releasing the pedals will stop the flow of gas, and pulling up on the pedals will allow gas to escape from the tire or tire liner. 
   Pedal  78  controls the rotation of chuck  22 . Pressing down on pedal  78  rotates chuck  22  clockwise, pulling up on pedal  78  rotates the chuck counterclockwise, and removing one&#39;s foot from the pedal will cause the chuck to cease moving. 
   A tool holder  80  may be provided as a convenient place to store an elongate lift tool used during tire and liner mounting/dismounting. Wheels  82  are preferably provided to enable a user to more easily move machine  10 . In this regard, the front of the machine may be lifted by grasping saddle  25  so that the machine can be rolled. 
   Referring now to  FIG. 7 , machine  10  may also include an articulated head  84  and a tire bar  86 . Articulated head  84  fits on the opposite end of shaft  58  from roller  54  and secures to the shaft by way of a removable pin  88 . In  FIG. 7 , head  84  is mounted in its storage position. When the operator wishes to use head  84 , bar  58  is slid out of receiver  62  and then reinserted from the opposite end (i.e., with roller  54  toward back  20  of machine  10 ). Head  84  is then reattached to the end of bar  58  opposite roller  54 . Articulated head  84  is shaped so as to assist the operator in removing a tire sidewall and tire bead when the tread portion of the tire has torn away from the remainder of the tire. Such a situation sometimes happens when a tire “blow out” occurs. 
   Tire bar  86  (also shown in  FIG. 10 ) fits over contact block  40  and preferably has an arcuate shape configured to apply distributed pressure to the top of a tire  90  located in saddle  25 . Using cylinder  44 , bar  86  can be pressed against tire  90  to achieve ovalation. That is, the tire is pressed into a slightly oval shape. In this oval and secure shape, it is easier for the operator to remove or insert a tire liner. 
   The process of inserting or removing a tire liner  91  will now be described. To insert a tire liner, the operator places tire bar  86  on contact block  40  and lowers the bar onto the tire by operating lever  46 , thereby pressing block  40  downward. Once the tire is sufficiently ovalated, the operator can more easily manually press the tire liner into the tire&#39;s interior. To remove a tire liner, the operator once again ovalates the tire with bar  86  (as shown in  FIG. 11 ). Then, the operator uses a special bar  93  having a handle at one end and a weld mark at a predetermined point to remove the liner. Bar  93  is inserted between the tire and the liner at the  12  o&#39;clock position. Bar  93  is then inserted until the weld mark aligns with the tire&#39;s upper bead edge. After this, bar  93  is pulled down until its tip can be rested in a notch  92  in saddle  25 . Using notch  92  as a fulcrum, the operator may now pull forward and remove the liner from the tire. 
   The process of mounting and demounting a NASCAR-type tire on machine  10  will now be described with reference to all of the Figures, but in particular reference to  FIGS. 6 and 7 . A tire  90  mounted on a rim is first mounted to chuck  22 , and centering cone  24  is threaded onto the chuck and tightened so as to secure the rim to the chuck. 
   With the tire-rim assembly mounted to chuck  22 , the operator positions upper offset roller  54  at the edge of the tire-rim interface and locks this position into place with cam lock  69 . While depressing pedal  78  to begin rotating the tire-rim assembly, the operator incrementally lowers roller  54  so as to push the tire&#39;s top bead into the rim&#39;s drop center. At this point, mount/dismount head  52  is placed on the rim&#39;s top edge (as shown in  FIG. 12 ) by manipulating arm  50 . Then, both the tire&#39;s bead and the liner&#39;s bead should be lubricated, which will minimize the frictional forces exerted between the liner, the tire, and the rim&#39;s edge. 
   Next, the operator positions contact block  40  at a position approximately 180 degrees about the tire from mount/demount head  52 . Contact block  40  is brought down to press the tire&#39;s sidewall even with the rim&#39;s drop center. At this point, the lift tool  95  is retrieved from tool holder  80  and used to pry the tire&#39;s top bead over the front edge of mount/dismount head  52  (see  FIG. 13 ). Slow rotation of the tire will allow the mount/dismount head to begin removing the top bead. Contact block  40  should be moved up and away from the tire as the wheel rotates. 
   Once the top bead is completely above the rim&#39;s top edge, the lift tool is used to pry the liner&#39;s top bead over mount/dismount head  52 . In some cases, it may be necessary to apply some force to the tire sidewall with roller  54  to expose the liner&#39;s top bead. Rotating the lift bar over the mount/dismount head lifts the liner&#39;s bead over head  52 . Rotation of chuck  22  will enable head  52  to raise the liner&#39;s top bead above the rim&#39;s top edge. 
   At this point, removal of the lower bead may begin. This process begins by positioning lower offset roller  56  near the intersection of the lower bead and the rim. While rotating the chuck by depressing pedal  78 , the operator slowly raises roller  56  until the lower bead is pushed into the rim&#39;s drop center. With head  52  still positioned near the rim&#39;s top edge, contact block  40  is positioned about 90 degrees clockwise from head  52  to hold the tire in the drop center position. That is, the front of contact block  40  pulls up on the tire&#39;s top bead (and the liner&#39;s top bead) to tilt the tire and keep that side of the lower bead in the drop center. 
   Next, the operator rotates the rim until contact block  40  is opposite head  52  (hinged arm segments  34  and  36  enable contact block  40  track the rim&#39;s rotation). Using the lift tool, the operator inserts the end of the tool under the liner&#39;s lower bead at head  52  and pries the lower liner bead onto head  52 . Contact block  40  may now be moved out of the way. With the lower liner bead on head  52 , the rim is rotated until the liner is removed from the rim. After removing the liner, the tire&#39;s lower bead can be removed similarly by prying the lower bead over head  52  and rotating the rim. The tire and tire liner are now completely removed from the rim. 
   Mounting a tire to a rim will now be described. First, the previously discussed process of inserting the tire liner into tire  90  should be performed. Next, the rim should be mounted to chuck  22  with centering cone  24 . The beads of the tire and tire liner should be well lubricated to ease the process of mounting the tire. This lubrication process may be conveniently performed with the tire in saddle  25 . 
   Next, the tire is moved from the saddle to atop the rim. Mount/dismount head  52  is then positioned at the rim&#39;s top edge and the tire&#39;s lower bead is positioned below head  52 . While holding the tire at an angle and manually pressing from above, rotation of the rim by the operator will allow the lower tire bead to be forced below the rim&#39;s top edge. 
   Once the lower tire bead is over the top edge, reversal of the rotation direction by pulling up on pedal  78  allows the liner&#39;s lower bead to drop into mounting position on head  52 . Then, pressing down on pedal  78  to rotate in the clockwise direction will force the liner&#39;s lower bead over the top edge. Next, the lift tool can be used as an aid to press the upper tire liner bead down over the leading part of head  52 . Now, clockwise rotation of the rim will mount the top liner bead by having head  52  force it below the rim&#39;s top edge. 
   To mount the tire&#39;s top bead, upper offset roller  54  is brought into position on the tire&#39;s sidewall and pushes the sidewall even with the rim&#39;s drop center. Contact block  40  is then brought into position just ahead of roller  54 , pressing the tire&#39;s sidewall into the drop center. Rotation of the rim at this point will allow head  52  to force the tire&#39;s top bead into the rim&#39;s drop center. Once the top bead is mounted, roller  54 , contact block  40 , and head  52  are moved out of the way. 
   With the tire mounted to the rim, the tire and tire liner can now be inflated. Machine  10  is fitted with two gas supply systems and separate inflation hoses  97  and  99  ( FIG. 1 ) so that both cavities (between the tire and the liner and between the liner and the rim) may be inflated simultaneously. Pedals  74  and  76  control the gas flow from the gas supplies to the inflation hoses and into the tire and tire liner. Pressing down allows gas pressure to enter the tire and tire liner, while pulling up on the pedals will release pressure from the cavities. Twin inflation gauges  70  and  72  may be used to adjust the tire and tire liner to desired pressures. 
   At this point, the tire is mounted, inflated, and ready to be mounted on a vehicle. 
   While one or more preferred embodiments of the invention have been described above, it should be understood that any and all equivalent realizations of the present invention are included within the scope and spirit thereof. The embodiments depicted are presented by way of example and are not intended as limitations upon the present invention. Thus, those of ordinary skill in this art should understand that the present invention is not limited to these embodiments since modifications can be made. Moreover, tire changing machines in accordance with the present invention may include some, most or all of the various implements and features described herein. It is further contemplated that various features described herein may be adapted to retrofit existing tire changing machines and are thus fully patentable in their own right. Therefore, it is contemplated that any and all such embodiments are included in the present invention as may fall within the scope and spirit thereof.