Abstract:
A roller skate with improved performance including a substantially U-shaped frame supporting in-line wheels. The skate comprises dampers that are adapted to absorb forces applied to the wheels and can be deactivated by tilting the frame.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a roller skate with improved performance. 
     Conventional in-line skates comprise a shoe associated with a substantially U-shaped frame supporting a plurality of in-line wheels between the wings of the frame. 
     These conventional skates have a drawback that is due to the rigidity of the frame because the wheels transmit every force produced by the ground to the frame and therefore directly to the shoe, thus causing fatigue to the user&#39;s foot. 
     U.S. Pat. No. 2,552,987 discloses a roller skate that has a rigid support for a shoe, below which two pairs of arms are rotatably associated at one end; a wheel is rotatably associated between each one of said pairs of arms. 
     Each one of said pairs of arms can freely oscillate, at one end, in contrast with a flexible element that is interposed between said end and the lower surface of the rigid support for the shoe. 
     Although this solution allows to compensate for any unevennesses of the ground, it has the drawback that it performs this compensation or damping also when it is not required: in fact, during the pushing action, part of the force transmitted to the wheels is absorbed by the compression of the springs, and therefore there is a dispersion of forces that limits the efficiency during the pushing action. 
     Likewise, the drawback is felt when the user practices the sport of slalom, since every sudden change in direction is matched by a further compression of the springs; on one hand, this limits the sensitivity of the athlete, and on the other hand, it can cause unpleasant conditions in which the springs compress and elongate during slalom, leading to discordant movements during sports practice and consequently hindering the athlete&#39;s performance. 
     The springs are a drawback also in speed skating. They would in fact imbalance the athlete in that specific position he/she must assume in order to reach the maximum possible speed; this position usually entails bending the legs and lowering the trunk and is therefore not easy to maintain. 
     SUMMARY OF THE INVENTION 
     The aim of the present invention is to eliminate the technical problems and the drawbacks of the mentioned prior art by providing a skate that allows the user to compensate for the unevennesses of the ground surface and to optimally transmit forces during the pushing action. 
     Within the scope of the above aim, an important object is to provide a skate in which these two apparently contrasting characteristics can be achieved automatically without forcing the user to select them beforehand. 
     Another important object is to provide a skate that is structurally simple and is reliable and safe in use. 
     This aim, these objects, and others which will become apparent hereinafter are achieved by a roller skate with improved performance comprising a substantially U-shaped frame having wings supporting a plurality of aligned wheels therebetween, characterized in that it comprises damping means adapted to absorb forces applied to the wheels, said damping means being deactivated by tilting said frame. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further characteristics and advantages of the invention will become apparent from the detailed description of a particular but not exclusive embodiment, illustrated only by way of non-limitative example in the accompanying drawings, wherein: 
     FIG. 1 is a cross-section view of the skate, according to the invention; 
     FIG. 2 is a view, similar to the preceding one, of the skate in the condition in which the user is pushing; 
     FIG. 3 is a sectional side view, taken along the plane III--III of FIG. 1; 
     FIG. 4 is a view, similar to FIG. 2, of the skate, according to a second embodiment of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the above figures, the reference numeral 1 designates a skate comprising a shoe 2, which is constituted for example by a quarter that is articulated to a shell 3 and below which a substantially U-shaped frame 4 is associated. 
     A plurality of wheels 7 are associated between the wings 5a and 5b of the frame 4 and are thus mutually aligned. 
     Two spacers 8a and 8b are arranged coaxially to the axis of each pivot 6, at the wings 5a and 5b; said spacers are interposed between the head 9 of each pivot 6 and two shoulder rings 10a and 10b that are also coaxial to each pivot 6 and are associated at the hub and at the wheel. 
     Said two spacers 8a and 8b keep each wheel 7 arranged centrally with respect to the frame 4, so that the median longitudinal plane 11 of the frame 4 coincides with the median plane 12 of each wheel. 
     Said two spacers 8a and 8b are flexible and can optionally be interposed between the inside surfaces of the wings 5a and 5b of the frame 4 and said two rings 10a and 10b. 
     The skate comprises means that are adapted to absorb forces applied to the wheels 7; said means are constituted by two pads 13a and 13b that are arranged partially coaxially to the two spacers 8a and 8b, are associated with them on the opposite side with respect to the ground 14, partially affect an adapted seat formed on the wings 5a and 5b, and also protrude towards the facing two rings 10a and 10b. 
     Said pads 13a and 13b can be compressed elastically so as to allow, as shown in FIG. 1, damping of the wheels 7 if said wheels make contact with unevennesses of the ground 
     The skate also comprises means that are adapted to deactivate said means adapted to absorb the forces applied to the wheels, when the frame 4 is tilted; said deactivation means are constituted by at least one protrusion that is located at each wheel and protrudes from at least one of the two inside lateral surfaces of the wings 5a and 5b of the frame 4; preferably, there are two protrusions 15a and 15b for each wheel, and said protrusions protrude from each one of the inside lateral surfaces of the wings 5a and 5b. 
     Said protrusions 15a and 15b protrude by such an extent that they do not affect, when the skate is used at right angles to the ground, the planes of arrangement of the two rings 10a and 10b, so as to allow their oscillation without mutual interaction. 
     Furthermore, the protrusions 15a and 15b are arranged slightly above the plane of arrangement that lies transversely to the wings 5a and 5b and passes through the upper end of the two rings 10a and 10b in the condition in which the skate is arranged approximately at right angles to the ground and when the ground is even. 
     If the user tilts the frame 4 with respect to the ground, for example when he needs to push, each wheel 7, due to the forces involved, tends to partially compress, as shown in FIG. 2, the spacer 8b and the pad 13b as a consequence of the shift of said wheel towards the wing 5b. 
     In this manner, the ring 10b is arranged below the protrusion 15b, preventing the compression of the pads 13a and 13b and thus preventing the damping of the wheel and therefore the shift of the pivots 6 transversely to the wings of the frame. 
     FIG. 4 shows a second embodiment of the invention wherein like reference numerals denote similar features of FIGS. 1-3. 
     According to the second embodiment, skate 101 has flexible or compressible elements 108a, 108b having a different degree of resilience. In this manner the wheel 7 oscillate, as shown in FIG. 4, instead of shifting along the axis of the pivot 6, so as to cause for example a partial compression of the pad 13a with a consequent axial displacement between the median longitudinal plane 11 of the frame and the median plane 12 of the wheel 6, so as to form an angle α between them. 
     In any case, even in this condition the edge of the ring 10b interacts with the protrusion 15b, and therefore the forces are again transmitted directly from the foot to the wheel during the pushing action, without any further damping of said wheel between the wings of the frame 4. 
     It has thus been observed that the invention has achieved the intended aim and objects, a skate having been provided that allows both to optimally transmit the forces from the foot to the wheels during the pushing action and to compensate, during the other steps of skating, for any unevennesses in the ground, by virtue of the possibility of damping the impacts to which the wheels are subjected. 
     The skate according to the invention is of course susceptible of numerous modifications and variations, all of which are within the scope of the same inventive concept. 
     The dimensions and the materials that constitute the individual components of the structure may of course be the most pertinent according to the specific requirements.