Abstract:
The device is used for facilitating a tire fitting and is usable in combination with a self-centering platform, rotatable about an axis, and with a fitting tool. The device is constituted by an auxiliary tool provided with a frame and having a lower free end which is removably constrainable to the self-centering platform. The frame comprises a support which, when the free end is constrained to the platform, is vertical, lateral and external of the wheel. A pusher element is connected to the support and can move in a parallel direction to a longitudinal axis of the support. The pusher element interacts contactingly with a tire wall situated facing upwards and forces an upper bead to remain below an upper edge of the rim during rotation of the self-centering platform in order to achieve tire fitting.

Description:
BACKGROUND OF THE INVENTION 
     The invention especially relates to a device which can be used together with a self-centering platform and a fitting tool. The platform is rotatable about preferably vertical a rotation axis. A vehicle wheel rim can be fitted, gripped and centered on the platform, together with a tire to be fitted onto the rim. 
     Before mounting, the upper bead of the tire is placed above the upper edge of the wheel rim; the fitting tool is positionable above the upper bead and can push the bead beneath the upper edge of the rim; during tire fitting the fitting tool acts on at least a part of the circumference of the upper bead (being the bead situated uppermost when the tire is loaded on the platform) of the tire by effect of a rotation of the platform; the device comprises an auxiliary tool which during operation can be associated to a part of the upper bead in order to force that part of the upper bead to remain beneath the upper edge of the rim during the rotation of the platform to carry out the tire mounting. 
     A device of this type is already known, in which the auxiliary tool comprises a clamp which is couplable to the upper edge of the wheel rim and which is equipped with a screw-locking element destined to interact contactingly with the upper bead. However, a clamp destined to be coupled on the rim of a certain type of wheel is not usually suitable for use with another type of wheel. 
     Consequently, in order to mount tires on many different types and models of wheels, a considerable number of clamp devices are needed, each having a clamp which is suitable for coupling with each type of wheel. 
     SUMMARY OF THE INVENTION 
     The main aim of the present invention is to provide a universal device for use with every type of wheel. 
     An advantage of the invention is that it provides a device by means of which tire fitting can be achieved very quickly and efficiently. 
     Another advantage of the invention is its simplicity of use. 
     A further advantage is that it prevents any relative sliding between the tire and parts of the device during the mounting operation. 
     The invention enables a good fitting and effective settling of the tire beads in the housings in the rim with only a contained exertion of force. 
     These aims and advantages and more besides are all achieved by the invention of the object, as it is characterised in the accompanying claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further characteristics and advantages of the present invention will better emerge from the detailed description which follows, of a preferred form of embodiment of the invention, illustrated purely by way of non-limiting example in the accompanying figures of the drawings, in which: 
     FIG. 1 is a partially-sectioned schematic lateral view in vertical elevation of an embodiment of the invention, in a first operational configuration; 
     FIG. 2 shows the invention of FIG. 1 in a different operational configuration. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the above-mentioned figures of the drawings,  1  denotes in its entirety a device for facilitating a fitting of a tire  2 . The device  1  can be used in combination with a self-centering platform  3  and with a fitting tool  4 . 
     The platform  3 , of known type, is rotatable about a vertical rotation axis x—x. 
     A rim  5  of a wheel bearing a tire  2  to be fitted thereon can be positioned, centered and gripped on the platform  3 . The rim  5  of the wheel has two circular edges, one upper  50  and the other lower  51  (with respect to the lie plane of the rim  5  on the platform), and a lateral channel  52  affording seatings in which an upper bead  20  and a lower bead  21  (again, with respect to the lie plane of the tire  2  on the platform) of the tire  2  can be fitted. 
     Before fitting the lower bead  21  is located in the lateral channel  52  of the rim  5 , while the upper bead  20  of the tire  2  is located externally of the channel  52  and above the upper edge  50  of the rim  5 . 
     The fitting tool  4 , of known type, can be positioned above the upper bead  20  in order to push it below the upper edge  50  of the rim  5 . During the tire fitting operation the fitting tool  4  acts on at least a part of the circumference of the upper bead  20  of the tire by effect of a rotation of the platform  3 . 
     The device  1  essentially comprises an auxiliary tool  6  which can be associated with a zone of the upper side of the tire in order to force said zone and especially the upper bead  20  zone to fit and stay below the upper edge  50  of the rim  5  during rotation of the platform  3  in order to complete the tire fitting. This auxiliary tool  6  comprises a frame  60  which is constituted by a threaded rod predisposed in such a way as to be constrainable at a lower end thereof to the self-centering platform  3 . 
     A horizontal rod  66  is solidly fixed to a lower end of the frame  60 ; the rod  66  bears at a free end thereof an interconnecting element  67  which can be joint-coupled to an edge of the self-centering platform. The element  67  is constrained to the rod  66  in such a way as to be free to oscillate about a pivot  68 , with a horizontal rotation axis. This articulation is intended to enable the tool  6  to be adaptable to the various different sizes of the rims  5  which will be mounted on the platform  3 . The frame  60  is specially sized so that when the element  67  is coupled to the edge of the self-centering platform  3  the frame  60  is located externally of the wheel and extends vertically, projecting above the wheel. 
     A support sleeve  61  is slidably coupled on the frame  60 . This sleeve  61  is axially slidable along a threaded rod which is a part of the frame  60 . The threaded rod bears a radial support arm  63 , on which a pusher element  62  is freely slidably coupled; this pusher element  62  will interact contactingly with the upper wall of the tire  2 . 
     The arm  63  is provided with a free end  69  which is predisposed to be pressed into contact with the upper edge  50  of the rim  5  gripped on the self-centering platform  3 . 
     A screw locking member  64  is provided, which acts on the sleeve support  61  and thus on the arm  63 , pressing the free end  69  of the arm against the edge  50  of the rim  5  and fixing the whole device  1  to the assembly constituted by the platform  3  and the rim  5 . This configuration forces the pusher element  62  into a position in which it locks the upper tire wall and relative bead  20  below the rim edge  50 . 
     The tire  2  is fitted as hereinafter described. The wheel is fixed on the platform  3 . The tire  2  on the wheel must be coupled to the rim  5  starting from a configuration in which the lower bead is internal of the lateral channel  52  and the rim  5  and the upper bead  20  is external of the lateral channel  52 , above the upper edge of the rim  5 . The fitting tool  4  is lowered (by control means of known type) and pushes a part of the upper bead  50  internally of the lateral channel  52  below the upper edge  50  of the rim  5 . During this phase, only a small area of the upper bead  50  is pushed into the lateral channel  52  of the rim  5 , while the greater part of the circumference of the upper bead  50  remains outside the lateral channel  52  and above the upper edge  50 . 
     Then the auxiliary tool  6  is applied at the zone of the bead inserted in the lateral channel  52 . The tool  6  is used to couple the joint element  67  to the edge of the self-centering platform  3 , and then the screw locking member  64  is rotated so as to displace the sleeve support  61  and consequently the pusher element  62  downwards. 
     The locking member  64  presses the support arm  63  so that the end  69  of the arm  63  is pressed against the edge  50  of the rim  5  so as to fix the frame  60  and therefore the whole device  1  to the assembly constituted by the platform  3  and the rim  5 , forcing the pusher element  62  to keep the upper wall of the tire  2  and the bead  20  pressed below the rim  5 . In this configuration, the coupling of the joint element  67  to the edge of the self-centering platform  3  creates a simple and safe lock since, by effect of the forces in play, the element is subject to a torque which tends to produce a rotation thereof about an axis which is tangential to the self-centering platform  3 . 
     Thus a configuration is reached in which the fitting tool and the auxiliary tool cooperate, one by the side of the other and at short distance one from the other, to constrain a relatively small part of the wall and thus of the upper bead  20  to stay within the lateral channel  52  in the mounting position. The remaining part of the tire  2  stays for now outside the channel  52 ; in particular, the part of the tire  2  which is diametrically opposite the part which has already been coupled to the rim  5  is decidedly raised above the upper edge of the rim  5 . At this point the platform  3  is commanded to rotate. By effect of the rotation the auxiliary tool  6  rotates together with the platform  3 , while the fitting tool  4 , which does not rotate, can interact with the circumference of the upper bead  20  to force the bead into the lateral channel  52  of the rim  5 . During this phase the auxiliary tool  6  has the task of preventing the parts of the bead  20  distanced from the fitting tool  4  during the rotation from disengaging from the rim  5 , exiting from the channel  52 . 
     The auxiliary tool  6  functions as a contrast element opposing the force which during the rotation of the platform  3  would tend to eject the part of the tire  2  furthest from the fitting tool from its seating in the channel  52  of the rim  5 . 
     During rotation the pusher element  62  is in contact with the part of the upper wall whose bead  20  had previously been forced to enter below the upper edge of the rim  5  and had been inserted into the lateral channel  52  before the start of the rotation. This pusher element  62 , in cooperation with the frame on which it is mounted (which frame is inferiorly connected to the platform  3 ), functions as a contrast element preventing the raising of the above-mentioned part of the bead, holding it in position. When the platform  3  has rotated by a little less than a full revolution, the fitting tool  4  is once more side-by-side with and at a short distance from the auxiliary tool  6  (but on the opposite side from the position at the beginning of the rotation), and the insertion of the tire  2  in the channel  52  is complete. 
     It should be observed that, during the rotation of the platform  3 , the part of the tire  2  in contact with the pusher and contrast element is subject to radial displacements with respect to the rim  5  and that consequently the pusher element slides on the arm carrying it, following these radial displacements, solidly with the above-mentioned part of the bead which it is in contact with, and drawn thereby. FIGS. 1 and 2 evidence the radial displacement of the upper bead and the pusher element. The ability of the pusher element  62  to move along the arm  63  means that there is no drag of the pusher element on the tire wall it is in contact with.