Abstract:
A swing arm style tire changer includes a base ( 1 ), a workbench ( 2 ), an upright stem ( 12 ), a swing arm ( 10 ) and a dismounting head ( 14 ). The swing arm ( 10 ) is attached to the upright stem ( 12 ) and is capable of rotating horizontally. The swing arm style tire changer also includes a first helper arm ( 11 ) connected to the swing arm ( 10 ); under said first helper arm ( 11 ) and connected thereto is a tire-pressing wheel ( 15 ) that may be moved vertically upwards and downwards. The first helper arm ( 11 ) is attached to the swing arm ( 10 ) and is capable of rotating horizontally, and a pneumatic cylinder ( 8 ) is arranged on said first helper arm ( 11 ). The swing arm style tire changer also includes a second helper arm ( 7 ).

Description:
BACKGROUND OF THE PRESENT INVENTION 
       [0001]    1. Field of Invention 
         [0002]    The present invention relates to a device for mounting and dismounting a tire member to and from a rim body of a tire object, and more particularly to a swing arm style tire changer. 
         [0003]    2. Description of Related Arts 
         [0004]    The economic development has led to the development and advancement of transportation in which the high volume use of vehicles has resulted in the greatly increasing need for tire repairing. The step of changing tire which used to be performed manually by labor is now performed by employing machinery which greatly reduces the labor requirement and hence increases the efficiency. 
         [0005]    The Chinese patent publication number CN2188045Y has disclosed a tire changer device which includes a base; a rotatable work-bench mounted on the base comprising a jaw unit for securing the position of the wheel body; an upright stem having a top end comprising a rotatable swing arm mounted thereon; a tire changer arm mounted on the swing arm capable of moving upwardly and downwardly relative to the work-bench; and a tire changer head mounted on a bottom end of the tire changer arm. When the tire member is rotated together with the work-bench through the rotation movement of the work-bench, the tire changer head can perform the step of mounting or dismounting the tire member. Since the structural construction makes use of a suspending arm, the rigidity is relative low. As a result, the swing arm and the upright stem are easily deformed and distorted in shape caused by the force during the mounting or dismounting action, causing the tire changer head directly in contact or hitting the wheel body, thereby not only increasing a rotary resistance of the tire member, but also damaging the wheel body and the rim of the wheel body during rotation. 
       SUMMARY OF THE PRESENT INVENTION 
       [0006]    The invention is advantageous in that it provides a swing arm style tire changer comprising a tire changer head which is not easily be deformed or distorted in shape, hence preventing damages to a rim body of a tire object causing by the tire changer head. 
         [0007]    Additional advantages and features of the invention will become apparent from the description which follows, and may be realized by means of the instrumentalities and combinations particular point out in the appended claims. 
         [0008]    According to the present invention, the foregoing and other objects and advantages are attained by a swing arm style tire changer which comprises a base, a workbench supported by the base, an upright stem extended from the base, a swing arm mounted on the upright stem and capable of rotating horizontally, and a dismounting head. The swing arm style tire changer further comprises a first auxiliary arm unit connected to the swing arm which comprises a tire-pressing wheel at a bottom end of the first auxiliary arm unit, wherein the tire-pressing wheel is pointing downward and is capable of moving vertically. 
         [0009]    The present invention includes the first auxiliary arm mounted on the swing arm comprising the tire-pressing wheel at its bottom. When dismounting a tire member, the tire-pressing wheel is pressing on the tire member or the wheel member and receiving an upward force, while the tire changer head at the bottom of the swing arm is receiving the downward force from the tire member, the upward and the downward forces exerted on the swing arm and the upright stem are effectively offset by each other. Therefore, the swing arm and the upright stem are protected against deformation or distortion in shape. As a result, a reasonable distance between the tire changer head the rim body is maintained, the rotary resistance during the dismounting process is reduced, and the tire changer head is prevented from directly and physically in contact with the rim body, hence protecting the rim body from damages. 
         [0010]    Preferably, the first auxiliary arm mounted on the swing arm in such a manner that the first auxiliary arm unit is capable of rotating horizontally. 
         [0011]    Preferably, the first auxiliary arm unit comprises a first cylinder and a first piston rod operatively extended downward from the first cylinder, wherein the tire-pressing wheel is connected to a bottom end of the first piston rod. Therefore, the tire-pressing wheel is capable of moving pneumatically upward and downward through the first cylinder of the first auxiliary arm unit. 
         [0012]    The present invention is further enhanced through the provision of a second auxiliary arm unit connected to the upright stem in such a manner that the second auxiliary arm unit is capable of rotating horizontally, that the second auxiliary arm unit comprises a tire-pressing head at a bottom end of the second auxiliary arm unit pointing downward and the tire-pressing head is capable of moving vertically and assisting the operation for dismounting or mounting a tire member. 
         [0013]    Preferably, the second auxiliary arm unit comprises a second cylinder and a second piston rod operatively extended downward from the second cylinder, wherein the tire-pressing head is connected to a bottom end of the second piston rod. Therefore, the tire-pressing head is capable of moving pneumatically upward and downward through the second cylinder of the second auxiliary arm unit. 
         [0014]    The tire-pressing head also has a tire-pressing member and a tire-supporting member, further assisting the operation for dismounting or mounting a tire member, such that the tire-pressing head which is equipped with both of the tire-pressing member and the tire-supporting member for performing different functions, has greatly increase the overall effectiveness and efficiency of the tire changer with a simplified construction. 
         [0015]    Furthermore, the present invention further comprises an adapter unit detachably and securely connected to the bottom end of tire-pressing head in such a manner that a tapering end of the adapter unit is pointing vertically downward. When dismounting a tire member, the tapering end can be used to bias against the central through hole of the rim body so as to further stabilize the positioning of the rim body on the work-bench. 
         [0016]    Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings. 
         [0017]    These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The present invention is further illustrated in the following figures and described in the detailed description. 
           [0019]    FIG. 1 is an illustration of a tire changer according to a preferred embodiment of the present invention. 
           [0020]      FIG. 2  is a top view illustration of the relationship between a swing arm and a first auxiliary arm unit of the tire changer according to the above preferred embodiment of the present invention. 
           [0021]      FIG. 3  is an illustration for the partially enlarged view of a tire-pressing head of the tire changer according to the above preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]    Referring to  FIG. 1  of the drawings, a swing arm style tire changer of a preferred embodiment of the present invention comprises a base  1 , a swing arm  10  and a tire changer arm  9 . The base  1  having a base body comprises a work-bench  2  supported by the base body and an upright stem  12  mounted onto the base body, wherein the work-bench  2  is connected to a transmission system of the base body and operatively connected with the base body in such a manner that the work-bench  2  is capable of rotating along a vertical axis defined by the base body. In other words, the work bench  2  is rotatably mounted on the base body, adapted for rotating relative to the base body horizontally while being supported by the base body. The work-bench  2  comprises a positioning unit adapted for positioning a rim body  4  of a tire object, such that when the rim body  4  of the tire object is securely positioned on the work-bench  2  through the positioning unit, the rim body  4  will be guided to rotate along with the work-bench  2  coaxially and simultaneously. The swing arm  10  is mounted on an upper portion of the upright stem  12  which is above the level of the work-bench  2  in such a manner that the swing arm  10  is capable of rotating at a horizontal level around the upright stem  12  and above the work-bench  2 . The swing arm  10  has an end portion connecting to the tire changer arm  9  in such a manner that the tire changer arm  9  is capable of moving vertically such that a distance between the tire changer arm  9  and the work-bench  2  is adjustable and controllable. The tire changer arm  9  comprises a tire changer head  14  at an end portion of the tire changer arm  9 , wherein the tire changer head  14  further comprises a dismounting unit and a mounting unit, adapted for dismounting and mounting a tire member  3  from and onto a rim body  4  respectively. In other words, the tire changer head  14  is a dismounting head when used for dismounting a tire member  3  from the rim body  4  and is a mounting head when used for mounting the tire member  3  onto the rim body  4  of the tire object. 
         [0023]    Referring to  FIG. 2  of the drawings, a first auxiliary arm unit  11  of the swing arm style tire changer of the present invention, which is a first help arm, comprises a first connecting arm unit  16  mounting the first auxiliary arm unit  11  onto the swing arm  10  at one end such that the first auxiliary arm unit  11  is pivotally and rotatably supported through the connecting arm unit  16  and is capable of rotating along an axis which is defined by the first connecting arm unit  16 . Alternatively, the first auxiliary arm unit  11  may further provide a first lock unit adjustably locking a position of the first auxiliary arm unit  11  relative to a position of the swing arm  10 . It is worth mentioning that, as shown in  FIG. 2 , while the first auxiliary arm unit  11  is connected to the swing arm  10  through the first connecting arm unit  16  which is a pivot pin unit, other alternative connection for connecting the first auxiliary arm unit  11  and the swing arm  10  can also be used in the swing arm tire changer as long as the force transfer between the first auxiliary arm unit  11  and the swing arm  10  is achieved. 
         [0024]    The first auxiliary arm unit  11  comprises a tire-pressing wheel  15  and a first piston arrangement driving the tire-pressing wheel  15  in a vertical movement. In particular, the first piston arrangement comprises a first cylinder  8  comprising a first piston rod  13  extended downward, that the tire-pressing wheel  15  is connected to a bottom end of piston rod  13  of the cylinder  8  and is guided to move controllably through the piston rod  13  of the cylinder. For example, the piston arrangement is a pneumatic cylinder providing the piston rod  13  for rapidly lifting up or dropping down the tire-pressing wheel  15  in a vertical direction. 
         [0025]    The swing arm style tire changer of the present invention further comprises a second auxiliary arm unit  7 , which is a second helper arm, horizontally connected to an upper portion of the upright stem  12  such that the second auxiliary arm unit  7  is operative above the work-bench  2  and is capable of rotating horizontally around the upright stem  12 . The second auxiliary arm unit  7  comprises a second arm body, a tire-pressing head  6  and a second piston arrangement supported through the second arm body and adapted for driving and guiding a vertical movement of the tire-pressing head  6 . In particular, the second piston arrangement comprises a second cylinder  8  comprising a second piston rod  13  extended downward, that the tire-pressing head  6  is connected to a bottom end of piston rod  13  of the cylinder  8  and is guided to move controllably through the piston rod  13  of the cylinder. For example, the second piston arrangement is a pneumatic cylinder providing the piston rod for driving a vertical movement of the tire-pressing head  6 . The second auxiliary arm unit  7  further comprises two arm members pivotally connected together end-to-end to form the second arm body through which the tire-pressing head  6  can be guided to move at a horizontal level. Preferably, the two arm members, each having a connecting end, are pivotally and rotatably mounted at the connecting ends, that the first arm member is mounted onto the swing arm  10  at an opposite end to the connecting end for gaining pivotal support and is transversely extended from the swing arm  10 , that the second arm member having the connecting end connected to the first arm member is connected to the second piston arrangement at an opposite end to the connecting end, that the two arm members are adapted for providing and guiding the horizontal movement of the tire-pressing head  6  through the piston rod of the cylinder of the second piston arrangement, which is coaxially connected with the tire-pressing head  6 . In other words, the second piston arrangement is a pneumatic cylinder providing the piston rod  13  for driving a vertical movement of the tire-pressing head  6  and the first and second arm members are arranged for providing a horizontal movement of the tire-pressing head  6 . 
         [0026]    Referring to  FIG. 3  of the drawings, an adapter unit  5  may further be provided and connected to the tire-pressing head  6  for providing a force at a predetermined position of the rim body  4  of the tire object. The tire-pressing head  6  has a tire-pressing member  61 , a tire-supporting member  62  and an engaging slot  63 , wherein the adapter unit  5  is connected to the tire-pressing head  6  through the engaging slot  63  in such a manner that the adapter unit  5  is detachably and securely connected to the tire-pressing head  6 . The adapter unit  5  further provides a tapered end portion  51  pointing downward, adapted for applying a force which is vertically downward to an edge portion of the hole of the rim body  4 . 
         [0027]    The present invention further provides a method of use as follows. 
         [0028]    The method of dismounting a tire member  3  from a rim body  4  of the tire object comprises the following steps. The tire object is placed on a work-bench  2  and is securely retained on the work-bench  2  through the positioning unit thereof. A portion of the tire member  3  is then disengaged from the rim body  4  at a position near to the tire changer head  14  by moving the tire-pressing wheel  15  to bias against the tire member  3 . Accordingly, the tire changer head  14  is positioned at a distance of 2-3 mm away from the rim body  4  such that the tire changer head  14  is not directly and physically in contact with the rim body  4 . Then, the tire changer arm  9  is preferably locked by the pneumatic locking device to prevent vertical movement of the tire changer arm  9 . A first inner edge of the tire member  3  of the tire object is positioned at the dismounting unit of the tire changer head  14 , preferably by using a pry, then, the tire-pressing wheel  15  is switched into a position at an edge portion of the rim body  4  corresponding to the position of the tire changer head  14 . The adapter unit  5  is assembled at a tire-pressing head  6  and is positioned to bias against the central through hole of the rim body  4  by moving the tire-pressing head  6 . Lastly, the corresponding first inner edge of the tire member  3  can be dismounted from the rim body  4  of the tire object completely by rotating the work-bench  2  for one complete turn, which is defined as one cycle. In the above steps, since the tire-pressing wheel  15  is biased against the rim body  4  and is receiving an upward force while the tire changer head  14  is biased against the tire member  3  and is receiving a downward force, the upward and the downward forces exerted on the swing arm  10  and the upright stem  12  are effectively offset by each other. Therefore, the swing arm  10  and the upright stem  12  are protected against deformation or distortion in shape. As a result, a reasonable distance between the tire changer head  14  and the rim body  4  is maintained, the rotary resistance during the dismounting process is reduced, and the tire changer head  14  is prevented from directly and physically in contact with the rim body  4 , hence protecting the rim body  4  from damages. 
         [0029]    After completely dismounting the tire member  3  from the rim body  4 , the method further provides the following steps. The tire-pressing head  6  is repositioned such that the tire-supporting member  62  of the tire-pressing head  6  is arranged to support the tire member  3  at the opposed side (i.e. the bottom side) of the tire object in such a manner that a second inner edge of the tire member  3  is in contact with an edge of the rim body  4  at the first side. Then, the tire member  3  is dismounted from the rim body  4  by using the tire changer head  14 . Therefore, the tire member  3  is completely dismounted from the rim body  4  of the tire object. 
         [0030]    The present invention further provides a method of mounting the tire member  3  onto the rim body  4  of the tire object, comprising the following steps. The rim body  4  is firstly placed on the work-bench  2  and is securely retained through the positioning unit. The edge of the tire member  3  is positioned on the mounting unit of the tire changer head  14 , wherein the tire-pressing wheel  15  is moved to bias against the tire member  3  at a position near to the tire changer head  14  until the tire member  3  is at a position which is 5-6 mm below the mounting unit of the tire changer head  14 . Then, the adapter unit  5  is disassembled from the tire-pressing head  6  and the tire-pressing head  6  is moved to a position such that a horizontal distance is maintained between the tire-pressing head  6  and the tire changer head  14  while the tire-pressing member  61  is biased against the tire member  3  until the tire member  3  is positioned at a position corresponding to the rim body  4  which has the minimum diameter. Lastly, the work-bench  2  is rotated for one turn such that the tire member  3  is mounted onto the rim body  4  completely. In the above steps, since the tire-pressing wheel  15  is biased against the tire member  3  and is receiving an upward force while the tire changer head  14  is receiving a downward force from the tire member  3 . In other words, the upward and the downward forces exerted on the swing arm  10  and the upright stem  12  are effectively offset by each other. Therefore, the swing arm  10  and the upright stem  12  are protected against deformation or distortion in shape. As a result, a reasonable distance between the tire changer head  14  and the rim body  4  is maintained and the tire changer head  14  is prevented from directly and physically in contact with the rim body  4 , hence protecting the rim body  4  from damages. 
         [0031]    One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. 
         [0032]    It will thus be seen that the objects of the present invention have been fully and effectively accomplished. It embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.