Abstract:
A method of fitting a tire P and a removable tread support S on a one-piece wheel rim J, rim comprising a first rim seat, inclined outwards, and the tire P comprises a first bead and a second bead to be mounted respectively on the first and second rim seats, in which, before completion of fitting the support S on a rim bearing surface of the rim, the first bead is gripped at a given point and is moved radially outwards to radially separate this point on the first bead from the support S. The fitting of the support S on the rim bearing surface continues and the bead is released after completion of the fitting of the support S.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation of International Application No. PCT/EP01/15166, filed 20 Dec. 2001 and published 18 Jul. 2002 in French as International Publication No. WO 02/055325 A1, and further claims priority to French Application No. 01/00498, filed 11 Jan. 2001. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention concerns a method of mounting an assembly formed by a tire and a removable tread support, and more particularly an assembly intended to be mounted on a single-piece rim, at least one of whose seats is inclined outwards.  
         BACKGROUND OF THE INVENTION  
         [0003]    As described in the French patents FR 2 699 121, FR 2 713 557 and FR 2 713 558, such a rim has, seen in meridian section, a first seat whose axially outer end is on a circle with a diameter less than the diameter of the circle on which the axially inner end is situated (such a seat is said to be inclined outwards), a relatively wide rim bearing surface intended to receive a removable tread support ring, possibly a mounting well, and a second rim seat, a either identical to or different from the first rim seat. The rim, a tire having an adapted meridian carcass reinforcement profile and bead shape, and a removable support together form a rolling assembly which is of high performance in the case of running at low pressure or even zero pressure.  
           [0004]    The patent FR 2 720 977 describes a method of mounting, on a single-piece rim, a tire comprising a first bead and a second bead which will be mounted respectively on the first and second rim seat, and a removable support. The mounting method is such that:  
           [0005]    the support is, in a first step, placed inside the tire;  
           [0006]    the second bead and the support are placed on the rim, from the side opposite to the second rim seat, until they are positioned on the rim bearing surface,  
           [0007]    the process of fitting the support on the rim bearing surface is completed and the first bead is mounted on the first rim seat; and  
           [0008]    the second rim is mounted on the second rim seat.  
           [0009]    The document EP 1 048 496 A1 describes a device for implementing this mounting method in which the first rim and the support are simultaneously fitted on the rim by progressive application of an axial force against the first bead of the tire, itself being seated against the adjacent wall of the support. The tool applying the axial force is a freely rotating roller whereby this fitting takes place during a rotation of the rim which also drives the tire and support in rotation. This method is effective in the case of supports which, in the state in which they are fitted on the rim bearing surface, are in contact with the first tire bead or very close to it.  
           [0010]    The document FR99/10108 presents similar rims adapted to receive lightened supports for the tire tread. In the mounted state, these supports are separated from the inner wall of the tire bead by an appreciable distance, for example about ten centimeters. In the case of the mounting of tire/support assemblies on such rims, it can be seen that the bead has difficulty in following the movement of the support during the fitting of the support on the adapted rim bearing surface. The first bead may lose contact with the pressing roller in the radially outward sense. In this case, the bead may contact the top of the support and there is a risk of contamination due to the lubricant used to facilitate running at low pressure or zero pressure.  
           [0011]    As these rims usually have a circumferential well adjacent to the first rim seat (see FIG. 1), the first bead may position itself into this circumferential well during the fitting of the support on the rim bearing surface. There is then a great deal of difficulty in removing it from this position. If the bead remains positioned between the support and the pressing roller, the magnitude of the movement necessary for fitting the support imposes high flexion on the tire which may damage it. Finally, in each case, the correct fitting of the support may remain in doubt.  
         SUMMARY OF THE INVENTION  
         [0012]    The object of the invention is a method of mounting, on a single-piece rim J, comprising a first rim seat, inclined outwards, extended axially outwards by a projection of low height and joined axially inwards to a rim bearing surface intended to receive a tread support S, and a second rim seat, inclined outwards, whose axially inner end is on a circle with a diameter greater than the diameter of the circle on which the axially inner end of the first rim seat is situated, a tire P comprising a first bead and a second bead which will be mounted respectively on the first and second rim seats, and a removable support S, comprising the steps of:  
           [0013]    (a) placing said tread support S into said tire P,  
           [0014]    (b) placing, from the side opposite to the second rim seat, the second bead of said tire P and said tread support S on the rim J until positioned on said rim bearing surface;  
           [0015]    (c) fitting said tread support S completely onto said rim bearing surface and mounting the first bead on the first rim seat; and  
           [0016]    (d) mounting the second bead on the second rim seat,  
           [0017]    and characterized in that:  
           [0018]    the first bead seat of said tire P is gripped at a given location prior to completely pushing said tread support S on said rim bearing surface, then  
           [0019]    the given location of the first bead seat is moved radially outward to move the first bead seat radially away from said tread support S,  
           [0020]    the tread support S is then pushed completely onto said rim bearing surface, and  
           [0021]    the first bead seat is released after completing the pushing of the said tread support S on to said rim J.  
           [0022]    Moving the bead radially outward during the fitting of the support gives better control of the conditions of fitting the support. In particular, this has the advantage of avoiding contact between the first bead and the top of the support.  
           [0023]    Advantageously, the process of fitting the support S is completed by direct pushing with an application tool against the wall of the support S disposed on the side of the first bead while rotating the rim.  
           [0024]    Preferentially, the support S is fitted on the rim bearing surface of the rim J until there is contact between a stop on the application tool and the external projection on the first seat of the rim J. This has the advantage of precisely defining the maximum magnitude of the axial movement of the application tool.  
           [0025]    After having fitted the support on its rim bearing surface, the first bead is released and the normal mounting of the two beads on their rim seats is continued.  
           [0026]    When the rim has a mounting well disposed between the second seat and the rim bearing surface, the second bead may be placed in this mounting well during step (b). In this case, after having finished fitting the support on the rim bearing surface and before releasing the first bead, the first bead is moved axially outward to exert a traction on the second bead to create a local space between the second bead and the wall adjacent to the second seat of the mounting well. Then, a mounting lever is inserted into the space created between the second bead and the wall adjacent to the second seat of the mounting well. The insertion of this mounting lever makes it possible to remove the second bead from the mounting well to bring it outside the rim on the side of the second seat  13 ″ prior to its mounting on this second seat.  
           [0027]    Another object of the invention is a tool for fitting tire beads and a support S on a single-piece rim J, characterized in that it has:  
           [0028]    an elongate-shaped bracket having an axis A,  
           [0029]    a finger extending from said bracket in a direction B perpendicular said axis A; and  
           [0030]    a means for transmitting an application force from said bracket to a zone C projecting beyond said finger, said zone C being offset a distance D measured in the direction B from said axis A of said bracket.  
           [0031]    Advantageously, the tool has a stop disposed in the direction B relative to the bracket and offset relative to the finger in the direction A beyond the force transmission means. This stop can be a freely rotating roller and with an axis of rotation coaxial with or parallel to the axis A.  
           [0032]    The means for transmitting an application force can be a slider or a freely rotating pressing roller. This roller can have its axis of rotation A′ parallel to the axis A. The roller can be directly fixed to the finger. 
       
    
    
     DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0033]    The invention is illustrated by the accompanying drawings, where:  
         [0034]    [0034]FIG. 1 depicts schematically, seen in meridian section, an assembly consisting of support and rim as disclosed in the application FR99/10108;  
         [0035]    [0035]FIG. 2 depicts, in side view, a tool according to the invention;  
         [0036]    [0036]FIG. 3 presents, in side view, a variant of the tool according to the invention;  
         [0037]    FIGS.  4  to  13  illustrate schematically the different the steps according to the invention of the method of mounting the tire/support assembly on a rim similar to that in FIG. 1;  
         [0038]    [0038]FIG. 14 depicts schematically, seen in meridian section, a second assembly consisting of a support and a rim, without a mounting well, as disclosed in the application FR99/10108. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0039]    [0039]FIG. 1, shows a meridian section of a single-piece rim  10  as disclosed in the application FR 99/10108. This rim when coupled with a disc forms a single-piece wheel. The disc can also be manufactured independently of the rim and joined thereto later. The rim  10  comprises two frustoconical rim seats  13 ′ and  13 ″ with unequal diameters respectively D′ A  and D″ A . The diameter of a frustoconical seat means the diameter of its largest circular end. The generatrices of two seats  13 ′ and  13 ″ are inclined outwards, the diameters D′ A  and D″ A  respectively of their axially inner ends being greater than the diameters D′ B  and D″ B  of their axially outer ends. The two frustoconical seats are extended axially outwards by two projections or humps  15 ′ and  15 ″ of low height. The first seat  13 ′, intended to be mounted facing to the exterior of the vehicle, is extended axially outward by a frustoconical part  17  inclined at an angle α relative to the axial direction. The axially inner end of the frustoconical part  17  is also the end of the rim bearing surface  11  oriented axially to the exterior of the vehicle. The rim bearing surface consists of two seating zones  111  and  112  for the support S separated by a circumferential well  110 . The diameter of the rim bearing surface  11  is D N . The seating zone  112  is proximate to the second rim seat  13 ″ and is intended to be mounted to the interior of the vehicle. The seating zone  112  has its end proximate to the rim seat  13 ″ provided with a positioning projection or stop  16  intended to prevent the inward-axial movement of the tread support S which will be disposed on the rim bearing surface  11 . The second seat  13 ″ extends axially inwards by a flange  14  of low height h of about 3 to 4 mm. This flange  14  delimits, in conjunction with the position stop  16 , a mounting well  12  for fitting the tire bead which will be mounted on the seat  13 ″.  
         [0040]    The support S is made from a rubber-like material and has an axial width  1  substantially less than the axial width L of the rim bearing surface  11 . In the instant example, 1 is equal to about 0.5 L. When the rim includes a circumferential well  110 , the width  1  of the support S must be greater than the width  1   1  of the well  110 . In this case, the first seating zone  111  of the rim bearing surface  11  is useful only for the mounting and removal of the support due to the reduced axial width of the support S.  
         [0041]    The radially outermost face of the second seating zone  112  of the rim bearing surface  11  is provided with a circumferential groove  115  having a semicircular form with a small radius of about 4.5 mm. That is to say, the radius is substantially the same magnitude as the height of a projection  15 ′( 15 ″). The radially inner wall of the support S is provided with a protuberance  30 , preferably circumferential, intended to cooperate with the groove  115  in the second support seating zone  112  to prevent any axial movement of the support towards the first seat  13 ′ while in service. The protuberance  30  consists of the same rubber-like material as that of the support and may be reinforced or not. Where the protuberance  30  is reinforced, it will preferentially be reinforced by a circumferentially continuous elastic wire or filament, or a continuous strand of several elastic wires or filaments. That is to say, the filaments have a certain degree of extension under an elongation force and regain their initial shape as soon as the force disappears. The protuberance  30  is preferentially situated axially between the end of the radially inner face of the support S axially closest to the seat  13 ′ and the middle of the face. The axial distance V x  separating the mid-axis of the protuberance  30 , which is also the mid-axis of the groove  115 , from the end of the support seating zone  112  oriented to the exterior of the vehicle is between 0.1 and 0.2 times the axial width  1  of the support S. First, this is to have better centering of the support on the seating zone  112 . Second, this is to minimize the length of movement under compressive force of the protuberance on the support, although the circumferential elasticity of the protuberance  30  allows easy fitting of the support on the rim bearing surface  11 .  
         [0042]    [0042]FIG. 2 presents in side view a tool according to the invention. This tool  40  for fitting tire beads and tread supports comprises an elongate-shaped bracket  41  with a substantially cylindrical section of axis A, a finger  42 , a pressing roller  43 , and a stop  44 . This tool also comprises at one end a first fixing projection  410  adapted to snap into a tool support (not shown). The finger  42  extends in the direction B with a substantially linear part  422  of sufficient length to hold a tire bead. The finger  42  terminates in a hook  421  of low height. The direction B is substantially perpendicular to the axis A. The pressing roller  43  is fixed to the finger  42  by a second substantially cylindrical connecting projection  423 . The roller comprises an elastic ring  432  disposed around a ball bearing  431 . The ball bearing  432  fits around the second connecting projection  423 . The pressing roller  43  is thus free to rotate about its axis A′. The axis of rotation A′ of the roller is parallel to the axis A. The axial height of the elastic ring  432  and thus that of the pressing roller is about 30 to 50 mm. A third projection  411  is disposed at the end of the support  40  opposite to the fixing projection  410 . An elastic ring  44  is disposed around this support to serve as a stop. The end of the pressing roller  43  in the direction B opposite to the bracket  41  forms the force transmission zone C. The zone C is situated a distance D from the bracket  41 . D is greater than the distance separating the end of the hook  421  from the bracket  41 .  
         [0043]    [0043]FIG. 3 presents a variant  50  of the tool of the invention where the axis of the fixing projection is offset relative to the axis A of the support  51  in the direction B until it is substantially coaxial with the axis A′ of the pressing roller  43 . This offset distance can be as much as the distance D. The support  51  has a part  52  in the form of an S. The advantage of this variant is to facilitate installation on existing mounting machines without reducing the maximum acceptable width of the wheels.  
         [0044]    FIGS.  4  to  13  illustrate schematically the mounting method according to the invention for the example of a rim with a mounting well similar to that shown in FIG. 1. These figures illustrate the respective positions of the rim J, the support S and the beads  61  and  62  of the tire P, with the rim mounted on a horizontal, rotating shaft. The figures correspond to the respective positions as seen in a vertical plane passing through the axis of rotation of the rim.  
         [0045]    The first step is to insert the support S into the tire P. This insertion is described in the application FR 2 720 977 pages 3 and 4 and illustrated in FIGS. 1A, 1B and  1 C of that application. The support is inserted after ovalisation of the support and/or of the tire, or after curving of the support.  
         [0046]    Next, the wheel is mounted on a rotating shaft, horizontal in the instant example, of an appropriate mounting machine. An operator then mounts the second bead  62  of the tire P along with the support S positioned on the seating zone  111 . The tire P and the support S are then in the position illustrated in FIG. 4: the second bead  62  is placed (at least in the zone illustrated) in the mounting well  12 , the support S is fitted around the first support seating zone  111 , the first bead  61  remains completely outside the rim J.  
         [0047]    As illustrated in FIG. 5, the tool  40  then moves under the first bead  61  to grip the first bead  61  with the finger  42  of the tool  40 . Next, the tool  40  moves vertically until the radially bottom part of the roller  43  is above the rim bearing surface  11 . FIG. 6 illustrates this position. The arrow in FIG. 7 indicates how the tool  40  moves axially to apply the pressing roller  43  directly against the axially rear face of the support S while at the same time rotating the rim and thereby also rotating the tire and the support. This makes it possible to fit progressively the support S onto the rim bearing surface  11 .  
         [0048]    [0048]FIG. 8 illustrates an intermediate position of the fitting of the support. It can be noted that the bead  61  can move freely back on the finger  42  during this fitting, which substantially reduces-the bending forces imposed on the crown of the tire.  
         [0049]    [0049]FIG. 9 illustrates the completion of the fitting of the support onto the second seating zone  112 . The support seats against the projection  16  and the projection  30  on the support snaps into the groove  115  in the seating zone  112 . In this position, the stop  44  on the tool  40  seats against the projection  15 ′. The exact position of this stop  44  relative to the zone of application of the forces C is determined taking account of the deformations of the support S during its fitting. It is then possible to be certain that the support is in place correctly when the stop  44  contacts the projection  15 ′.  
         [0050]    After having completed fitting the support on the seating zone  112 , the tool  40  withdraws axially to exert a traction on the second bead. This traction slightly raises the bead  62  from the bottom of the mounting well  12  and leaves a free space between the bead  62  and the wall of the mounting well adjacent to the projection  14  on the second seat  13 ″ (see FIG. 10). A mounting lever  70  can then be inserted in this space to remove the second bead  62  from the mounting well  12  and place it outside the second seat  13 ″ (see FIG. 11).  
         [0051]    After having inserted the lever  70  and released the bead  62  from the mounting well  12 , the first bead  61  is released from the finger  42 . The first bead  61  is then fitted on the first seat  13 ′ by causing it to progressively pass over the projection  15 ′ by pressing the roller  43  against the first bead (see FIG. 13) while rotating the rim.  
         [0052]    After having completed the mounting of the first bead, the tool  44  is moved and, preferably, is reversed for mounting the second bead  62  on its seat  13 ″ while causing it to progressively pass over the projection  15 ″ by means of pushing the roller  43  while rotating the rim (see FIG. 12). If it is not possible to reverse the tool  40 , it is also possible to mount the second bead by pressing the roller  44 , preferably provided with a ball bearing. The tire P and the support S are then completely assembled on the rim J (FIG. 13). FIG. 14 presents, as seen in meridian section, a single-piece rim  80  as disclosed in FIG. 2 of the application FR 99/10108. This rim  80  does not have any mounting well and the seating zone  112  is directly connected to the axially inner end of the second rim seat  13 ″. The mounting method and the tool according to the invention are entirely applicable also to the mounting of a support S and of a tire P on such a rim. When the support is fitted by pressure of the pressure roller  43 , the axially front wall of the support pushes the second bead until it is fitted on its seat  13 ″.