Abstract:
A miniature vehicle and method for assembling one or more wheels on the vehicle which includes a chassis and a bodywork, wherein the method consists of introducing one end of a hub extending from a wheel through a stop element integrally formed with one of the chassis or the bodywork and maintaining the hub in position between opposing surfaces of the stop element. The vehicle produced is characterized in that each wheel is secured to a hub having an outer flange adapted to cooperate with the stop elements formed in one of the chassis and the bodywork in order to retain the hub against translation forces relative to an axis of a hub and wheel assembly.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method for assembling one or more wheels on a miniature vehicle, and to a miniature vehicle. 
     2. History of the Related Art 
     In miniature vehicles, which most often constitute toys for children, the wheels belonging to the same set of wheels are usually joined together, in rotation and in translation, by an axle, i.e. the wheels of the same axle rotate at the same time. This linkage in rotation and in translation is detrimental to the ability of these miniature vehicles to take corners and may lead to the child losing interest in the game. Certain miniature cars possess wheels which are independent in rotation on the same axle. In this case, these wheels are mounted by means of complex systems on the chassis or bodywork of the vehicle, which increases production costs thereof correspondingly and most often renders it fragile, which is incompatible with the use of the vehicle as a toy for a young child, in particular for a child younger than 36 months. 
     U.S. Pat. 5,380,231 proposes a miniature vehicle in which the attachment of the wheels is so unstable that the vehicle comes apart spontaneously in the event of a shock. The temporary attachment of the wheels on the chassis is effected without a stud element but by means of a complex device comprising spring-controlled levers. 
     In all cases, the tear resistance of the wheels obtained with prior-art devices is low and does not comply with the standards in force or planned. Moreover, the known devices are delicate to assemble, i.e. it is a long and expensive operation. 
     It is an object of the present invention to overcome these problems by a method for assembling one or more wheels on a miniature vehicle allowing an efficient attachment of the wheel or wheels with respect to the rest of the vehicle and a free rotation of one wheel with respect to the other wheel of the same set of wheels. 
     SUMMARY OF THE INVENTION 
     To that end, the invention relates to a method of assembling one or more wheels on a miniature vehicle comprising a chassis and a bodywork, characterized in that it consists in driving the end of a hub of a wheel through a stop element integral with or secured to chassis or, the bodywork, and in maintaining the hub in position driven in the stop element. 
     Thanks to the invention, assembly of a wheel on a miniature vehicle is particularly rapid and easy, as it suffices to exert a driving-in effort to position the wheel with respect to the vehicle. 
     According to an advantageous aspect of the method of the invention, the method may further consist in partially housing a spindle inside the hub of a first wheel, before driving the end of this hub through the stop element and in capping a free end of this spindle with a hub of a second wheel intended to be assembled opposite the first wheel by driving the end of the second hub through a second stop element integral with or secured to the chassis or bodywork. In this variant of the invention, a spindle, which may be made of metal, is thus captive between the two hubs of two wheels of the same set of wheels, which confers a good rigidity to the assembly thus formed, this spindle serving as axle for the set of wheels. 
     The invention also relates to a miniature vehicle assembled by the method of the invention, and to a miniature vehicle comprising a chassis, a bodywork and a plurality of wheels, characterized in that each wheel is integral with or secured to a hub bearing an outer flange adapted to cooperate with a stop element integral with or secured to chassis or said bodywork in order to immobilize said hub in translation in a direction of force with respect to the chassis or the bodywork. 
     In the miniature vehicle of the invention, cooperation of the flange of the hub and the stop element makes it possible to obtain a good tear force resistance of the wheel, insofar as the flange is adapted to immobilize the hub, and consequently the wheel, when a pull is exerted thereon to separate the vehicle. 
     In accordance with a first advantageous aspect of the device of the invention, the end of the hub remote from the wheel includes a chamfer adapted to facilitate introduction thereof in the stop element, this making it possible to correct an imprecise alignment of the hub and stop element when the hub is positioned opposite the stop element. 
     It may, in addition, be provided that the hub has at least one shoulder adapted to cooperate with the stop element, the chassis or the bodywork in order to immobilize the hub in translation in another direction with respect to the chassis or bodywork. Thanks to this aspect of the invention, the hub is therefore immobilized in the two directions of translation that it is capable of having with respect to the stop element. The only possible movement of the hub with respect to the stop element is therefore its rotation, which allows the wheel to rotate when the vehicle is moved. 
     According to another advantageous aspect of the invention, the hub is provided with a central orifice adapted to receive a part of a spindle forming the axle of a set of two wheels, which makes it possible to rigidify the assembly thus obtained. 
     According to a first embodiment of the invention, the stop element is formed by two deformable studs integral with the chassis or bodywork. The deformation of the studs allows the passage of the flange of the hub when it is introduced in the stop element. In this case, the bodywork of the vehicle may also be provided to include a stop adapted to abut against the hub so as to avoid pivoting thereof about an axis perpendicular to its principal axis. 
     According to a second embodiment of the invention, each stud comprises an under-cut end allowing the hub to be maintained in position. 
     In accordance with a third embodiment, the stop element may be formed by a block having a circular orifice centered on the axis of the hub of the wheel. The end of the hub is driven in this orifice thanks to the deformation of the block or of the flange of the hub. In this case, the hub may be formed by a plurality of supple plates, which allows such deformation. 
     Finally, according to another advantageous aspect of the invention, the hub is integral with the wheel. The hub may thus be force-fitted in the wheel. In any case, it constitutes therewith, possibly after fit thereof, a single piece easy to manipulate during the assembly operations and which cannot be dismantled by a child playing with the vehicle. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be more readily understood on reading the following description of three embodiments of a miniature vehicle with reference to the accompanying drawings, in which: 
     FIG. 1 is a schematic view in perspective of a miniature vehicle being assembled; 
     FIG. 2 is a view in section in the plane of the rear set of wheels of the vehicle of FIG. 1 being assembled, the bodywork having been removed; 
     FIG. 3 is a view similar to FIG. 2, with the wheels assembled; 
     FIG. 4 is a view in section along line IV--IV of FIG. 3; 
     FIG. 5 is a view similar to FIG. 3, of a second embodiment of the invention, the left wheel being shown in outside view; 
     FIG. 6 is a view in section along line VI--VI of FIG. 5; 
     FIG. 7 is a view similar to FIG. 5 of a third embodiment of the invention; and 
     FIG. 8 is a view in section along line VIII--VIII of FIG. 7. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring now to the drawings, the vehicle 1 of FIG. 1 essentially comprises a chassis 2 and a bodywork 3 mounted on the chassis by any suitable means within the scope of a person skilled in the art. Four wheels are distributed between a front set, formed by two front wheels of which the axes of rotation are aligned and a rear set formed by two rear wheels whose axes of rotation are likewise aligned. Each wheel comprises a hub 4a integral therewith and capable of supporting it. 
     According to the invention, each hub 4a has an outer flange 4b, i.e. extending radially with respect to the axis of the hub 4a. Stop elements 5 are formed on the upper surface of the chassis 2, constituted by two studs 5a and 5b integral with the chassis and separated by a space 5c whose width is slightly smaller than the diameter of the flange 4b. The chassis 2 also comprises four orifices 6, of which two are visible in FIG. 1, through which the hub 4a of each wheel 4 may be inserted in the direction of the corresponding stop element 5. 
     When the flange 4b comes into contact with the studs 5a and 5b, the latter are deformed and move apart, with the result that the width of the space 5c is momentarily increased, which allows passage of the flange 4b. In this way, the end of the hub 4a constituted by the flange 4b is introduced through the stop element 5. In order to facilitate such introduction, the end of the hub 4a includes a chamfer tapered conical portion 4c which constitutes the front face of the flange 4b. The axial effort exerted by the installer on the wheel 4 is therefore transformed, thanks to the chamfer 4c, into a radial and axial effort which makes it possible to move the studs 5a and 5b apart, using their deformable character. 
     On the contrary, the rear face 4d of the flange 4b facing the wheel 4 is substantially radial, with the result that, when the flange 4b has passed beyond the studs 5a and 5b, the rear face 4d constitutes a radial bearing face for the flange 4b on the studs 5a and 5b. Taking into account the geometry of the studs 5a and 5b, they are much more difficult to deform in a direction parallel to the axis XX&#39; common to the hubs of the two wheels of the rear set of wheels, with the result that they are not deformed when an effort of force in the plane of the axis XX&#39;, is exerted on wheel 4. In this way, the flange 4b and the stop element 5 are adapted to immobilize the hub 4a in translation in a direction of force of the wheel 4 with respect to the chassis 2. 
     In accordance with the method of assembly of the invention, the end of the hub 4a formed by the flange 4b is introduced through the stop element 5 and the hub 4a is maintained in position driven in the stop element 5 thanks to the geometry of the flange 4b . 
     Furthermore, the hub 4a has two shoulders 4e and 4f adapted to rest respectively against the edge of the studs 5a and 5b and against the edge of the orifice 6, when the end of the hub 4a is introduced beyond the stop element 5 with respect to the orifice 6. These two shoulders 4e and 4f of which one, for example shoulder 4e, may be constituted by a chamfer, serve to immobilize the hub 4a in translation in the direction of penetration of the hub 4a through orifice 6. In other words, their function is to prevent the wheel 4 from being driven too far in the orifice 6 or in the stop element 5. 
     According to an advantageous aspect of the invention, the vehicle of the embodiment of FIGS. 1 to 4 also comprises a spindle 7, for example metallic, partially inserted inside a central orifice 4g of the hub 4a of the wheels 4. When the two ends of the spindle 7 are capped by the hubs 4a of the two wheels of a set of wheels, this spindle constitutes an axle which gives a good mechanical stability to the set of wheels thus formed. In particular, it avoids any pivoting of the hub 4 perpendicularly to axis XX&#39; in a direction which would tend to move the end 4b of the hub 4a away from the upper surface of the chassis 2. 
     The method of assembly is as follows: the spindle 7 is partially housed inside the hub 4a of a wheel, a right one FIG. 2, then the hub 4a is introduced through the orifice 6 and its end 4b through the stop element 5. The free end 7a of the spindle 7 then passes beyond the hub 4a of the right wheel in the direction of the orifice 6 located on the left of FIG. 2. In this position, the end 7a is capped by the hub 4a of the left wheel by introducing the end of this second hub through a second stop element 5 the chassis 2, located to the left in FIG. 2. 
     In this way, the assembly effected, as shown in FIG. 3, is solid and allows a good attachment of the wheels 4 on the chassis 2. The outer diameter of the spindle 7 may be smaller than the diameter of the central orifices 4g of the hubs 4a, with the result that the wheels 4 are free to rotate with respect to the spindle 7, which allows a differential speed of the wheels located to the left and right of the miniature vehicle, when the latter follows a curved path. 
     FIGS. 5 and 6 show a second embodiment of the invention, in which the constituent elements similar to those of the embodiment of FIGS. 1 to 4 have identical references increased by 50. This embodiment differs from the preceding one in that it does not provide a spindle joining the hubs 54a of two wheels 54 belonging to the same set of wheels of the vehicle 51. As before, each hub 54a comprises an outer flange 54b of which the front face is formed by a chamfer 54c facilitating introduction thereof through a stop element 55. Each stop element 55 is constituted by two deformable studs 55a and 55b integral with the chassis 52. Each hub 54a comprises, as before, a substantially radial rear flange face 54d and two shoulders 54e and 54f adapted to immobilize, in the direction of penetration, the wheel 54 with respect to an orifice 56 of the chassis 52 and to the stop element 55. As before, the flange 54b cooperates with the stop element 55 to immobilize the hub 54a in translation in the direction of the plane of the axes XX&#39;. 
     The studs 55a and 55b each comprise an end, 55al and 55bl respectively, in under-cut with respect to the space 55c made between the two studs 55a and 55b, with the result that, when the hub 54a is engaged in the space 55c, it is retained upwardly by the ends 55al and 55bl. This makes it possible to avoid pivoting movements of the wheels 54 with respect to a horizontal axis perpendicular to axis XX&#39;. 
     In accordance with an alternative embodiment of the invention (not shown), it is also possible to provide that the bodywork of the vehicle comprises a stop which, when the bodywork is mounted on the chassis 52, is adapted to come into abutment against the upper face of the hub 54a. The function of this stop is also to avoid the above-mentioned pivoting of the hub 54a. In this case, the under-cut ends 55a1 and 55b1 may possibly be eliminated. 
     FIGS. 7 and 8 show a third embodiment of the invention, in which the elements similar to those of the embodiment of FIGS. 1 to 4 have identical references increased by 100. This embodiment differs from the preceding ones essentially in that the stop elements 105 are carried by the bodywork 103 of the vehicle 101. This bodywork comprises a fairing 103a extending transversely above a chassis 102. Each stop element 105 is formed by a block integral with the fairing 103a having a circular orifice 105a centered on the axis XX&#39; of the hubs 104a of the wheels 104 of the set of wheels in question. 
     Each hub 104 comprises at its end a flange 104b whose outer shape is substantially identical to that of the flanges 4b and 54b of the preceding embodiments. The hub 104a has a chamfer 104c, a radial rear face 104d and two shoulders 104e and 104f. This flange is adapted to cooperate with the stop element 105 in order to immobilize the hub 104a in the direction parallel to axis XX&#39; thanks to the rear face 104d of the flange 104b. As before, the hub 104a has shoulders 104e and 104f opposing penetration of the wheel 104 in the bodywork 103 insofar as the shoulder 104e comes into abutment against the stop element 105 and/or the shoulder 104f comes into abutment against the edge of an orifice 106 made for example in the bodywork 103. 
     The orifice 106 is circular and centered on axis XX&#39; of the hubs 104a. In order to allow deformation thereof when it must be introduced in the orifice 105a, the hub 104a is formed by a plurality of supple plates or fingers 104g which appear more particularly in FIG. 8, four in number. Thanks to their properties of suppleness, these fingers may be deformed in order to allow passage of the flange 104b in orifice 105a. 
     Hubs 54a and 104a of the second and third embodiments are, like hub 4a of the first embodiment, integral with the wheel to which they belong. However, it is also possible that the hub is constituted by a part distinct from the wheel and force-fitted in an axial orifice therein. In that case, the hub and the wheel constitute a unitary assembly which does not risk being dismantled by a child playing with the miniature vehicle of the invention. 
     It is, of course, possible to combine the characteristics of the different embodiments described, without departing from the scope of the invention. In particular, the hubs 54a and 104a may be provided with a central orifice for receiving a part of a spindle forming the axle of a set of two wheels.