Patent Publication Number: US-2004045680-A1

Title: Bead loosening device

Description:
FIELD OF THE INVENTION  
       [0001] The present invention relates generally as indicated to a bead loosening device and, more particularly, to a bead loosening device which can be used without removing the wheel from the tire testing machine.  
       BACKGROUND OF THE INVENTION  
       [0002] A tire-testing machine is used to measure force variation or imbalance forces of a rotating tire/wheel assembly. A common type of this machine comprises a road wheel mounted on a horizontal shaft and a horizontal spindle on which the to-be-tested tire/wheel assembly is rotatably positioned. When the road wheel is rotated (e.g., the shaft is driven by a motor), the tire/wheel assembly is turned and appropriate measurements can be taken.  
       [0003] The uniformity of a wheel can be dependent upon the location of the tire relative to the rim of the wheel. For example, deviations in the rim can either cancel out or aggravate deviations in the tire depending upon their radial alignment with each other. Accordingly, a tire will be rotated relative to the rim between test runs to ensure that all alignment possibilities are being considered.  
       [0004] In the past, between-run rotations were performed by first removing the wheel from the horizontal spindle. The removed wheel is then carried to a work station, whereat it is placed on a vertical shaft and a bead-loosening device is used to loosen the tire from the rim&#39;s flange. After the bead is loosened, the tire can be rotated relative to the rim and then the bead can be replaced in the flange. The wheel is then carried back to the tire-testing machine and placed back on the horizontal spindle so that the next test run can be done.  
       SUMMARY OF THE INVENTION  
       [0005] The present invention provides a bead loosening device which can be used without removing the wheel from the tire testing machine, so that between-run tire rotations can be performed more efficiently during testing procedures.  
       [0006] More particularly, the present invention provides a bead loosening device comprising a supporting arm having a first end pivotally connected to a lever, a shoe-carrying arm having a first end pivotally connected to the lever and a second end to which a shoe is attached, and a handle connected to the lever in such a manner that movement of the handle results in the shoe moving radially inward towards a sidewall of the tire. The shoe-carrying arm follows a curved path slanted towards the supporting arm. A ring can be attached to a second end of the supporting arm for engagement with a post. The shoe can comprise an arm-engaging wall attached to the second end of the shoe-carrying arm and a tire-engaging wall extending outwardly from a distal edge of the arm-engaging wall.  
       [0007] To loosen a tire from a rim while the tire/wheel assembly is installed on the tire-testing machine, the bead loosening device is positioned so that the shoe-carrying arm curves downwardly and the shoe is positioned adjacent a sidewall of the tire. The handle is then moved (e.g., pulled downwardly) so that the tire&#39;s sidewall is positioned inwardly by the shoe, and a bead of the tire is pushed out of engagement with the rim.  
       [0008] In a method of testing a tire according to the present invention, the to-be-tested tire/wheel assembly is placed on the horizontal spindle of the tire testing machine. The tire is then turned and appropriate measurements are taken. The bead loosening device is then used to remove the tire from the rim without removing the tire/wheel assembly from the spindle. The tire can then be rotated relative to the rim, and the rotated tire/wheel assembly can be turned so that a further set of test measurements can be taken.  
       [0009] The present invention provides these and other features hereinafter fully described and particularly pointed out in the claims. The following description and drawings set forth in detail a certain illustrative embodiment of the invention. This embodiment is indicative, however, of but one of the various ways in which the principles of the invention can be employed.  
       DRAWINGS  
       [0010]FIG. 1 is a schematic view of a bead loosening device according to the present invention installed on a tire testing machine.  
       [0011]FIG. 2 is a perspective view of the bead loosening device.  
       [0012]FIG. 3 is a side sectional view showing the bead loosening device pushing a tire sidewall to loosen the tire from the rim. 
     
    
    
     DETAILED DESCRIPTION  
     [0013] Referring now to the drawings and initially to FIG. 1, a bead loosening device  10  according to the present invention is shown installed on a tire testing machine  12 . The machine  12  comprises a road wheel  14  mounted on a horizontal shaft  16  and a horizontal spindle  18  on which the to-be-tested tire/wheel assembly  20  is rotatably positioned. When the road wheel  14  is rotated (e.g., the shaft  16  is driven by a motor), the tire/wheel assembly  20  is turned and appropriate measurements can be taken. To accommodate mounting of the bead loosening device  10 , a vertical post  22  is positioned behind the tire/wheel assembly  20  and suitably secured to the machine  12  or other appropriate surface.  
     [0014] Referring now to FIG. 2, the bead loosening device  10  is shown isolated from the tire testing machine  12 . The device  10  comprises a supporting arm  30  and a shoe-carrying arm  32 , each having an end pivotally connected to a lever  34 . In the illustrated embodiment, the supporting arm  30  is generally straight while the shoe-carrying arm  32  follows a curved path slanted in the direction of the supporting arm  30 .  
     [0015] A bearing ring  36  is attached to the distal end of the arm  30 , a shoe  38  is attached to the distal end of the arm  32 , and a handle  40  is attached to the lever  34 . The shoe  38  comprises a fan-shaped wall  42  which follows the curve of the arm  32  and a tire-engaging wall  44  extending outwardly from the distal edge of the wall  42 . The wall  44  has a roughly bow-tie shape which is bent to follow the curve of the distal edge of the fan-shaped wall  42 . The distal edge of the wall  44  has a curve which corresponds to the rim of the tire/wheel assembly.  
     [0016] In the starting position, the bearing ring  36  is received over the vertical post  22  so that the shoe-carrying arm  38  curves downwardly towards the post  22  and the shoe&#39;s tire-engaging wall  44  is positioned adjacent the tire side wall  46  along the upper edge of the wheel rim. (FIG. 1.) In the illustrated embodiment, the support arm  30  extends substantially horizontally from the post  22  to the lever  34  and the handle  40  extends substantially horizontally from the lever  34 . On downward (manual) movement of the handle  40 , the tire sidewall  46  is pushed inwardly by the shoe&#39;s wall  44  and the tire bead  48  is rolled out of engagement with its complementary rim portion (e.g., flange)  50 . (FIG. 3.)  
     [0017] In a method of testing a tire according to the present invention, the to-be-tested tire/wheel assembly  20  is placed on the horizontal spindle of the tire testing machine  12 . The road wheel  14  is rotated (e.g., the shaft  16  is driven by a motor), whereby the tire/wheel assembly  20  is turned and appropriate measurements can be taken. The bead-loosening device  10  is then used to loosen the tire from the rim&#39;s bead-engaging flange without removing the tire/wheel assembly  20  from the machine  12 . After the bead is loosened, the tire can be rotated relative to the rim and then the bead can be replaced in the flange. The road wheel  14  is then again rotated to turn the tire/wheel assembly  16  so that appropriate test measurements can be taken.  
     [0018] It may be noted that the bead-loosening device  10  of the present invention can be constructed from a bead-loosening device conventionally used to loosen the bead at a work station. At such a work station, the removed-from-the-machine tire is placed on a vertical shaft and the conventional bead-loosening device is used to loosen the tire from the rim&#39;s flange. The bead-loosening device  10  can be constructed by lengthening the conventional supporting arm and/or the conventional shoe-carrying arm, and by repositioning the conventional shoe-carrying arm so that it curves towards the distal end of the supporting arm.  
     [0019] Although the invention has been shown and described with respect to a certain embodiment, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such alterations and modifications and moreover is limited only by the scope of the following claims.