Abstract:
A structure associated with a motorcycle boot which is designed to restrict, in the event of accidental falls followed by contact at high speed with the ground, the movements of a leg-piece of the boot with respect to the axis of a heel-piece, comprises a first hinge, which is angularly movable in a substantially unlimited manner and axially movable between two stopping means, and second hinge which is movable only angularly in a restricted manner. Alternatively, the first and second hinges can be formed of elastomeric materials.

Description:
This is a division of U.S. patent application Ser. No. 10/031,551, filed Jan. 18, 2002 now U.S. Pat. No. 6,725,577, which was filed under 35 U.S.C. §371 from International Patent Application PCT/EP01/05284, filed May 9, 2001. 

   FIELD OF THE INVENTION 
   The present invention relates to a structure intended for restricting the movements in the main directions, i.e. longitudinal, rotary and torsional directions, of the leg-piece of an a boot with respect to the axis of an associated heel-piece in order to protect a motorcyclist&#39;s lower limbs. 
   BACKGROUND OF THE INVENTION 
   The dangers of severe injuries deriving from accidental impacts and falls are well known by people who practise motorcycling. The injuries can often involve the lower limbs, in particular the feet, and result from seemingly trivial manoeuvres or accidents, like setting a foot on the ground while the vehicle is travelling at high speed. In these circumstances the foot is subjected to severe stresses and, if it were not protected, quite severe consequences, such as fractures or other damages to the bones, and tearing of the Achilles tendon or of the ligaments in the region of malleoli would take place. 
   A need therefore exist of preventing, or at least limiting as far as possible, the said injuries which is satisfied by conventional boots comprising a rigid shell, enclosing the foot, and a leg-piece which is also rigid—enclosing the leg and hinged on the shell. During an accident these parts are obviously positioned between the limb to be protected and the obstacles encountered with the result of dampening the impacts and deflecting their action. 
   Even if motorcycle boots of this type are already available which greatly limit the possibility of bone fractures in the leg and foot and, when they are designed so as to surround at a sufficient extent the limb, are suitable for the protection against excessive torsional angles, no structure is presently available which is capable of restricting certain relative movements of the foot and leg during a motorcycling accident that lead to excessive bending angles between the foot and the leg, either in the forward or backward direction. 
   SUMMARY OF THE INVENTION 
   The main object of the present invention is therefore to disclose a structure for the use in a motorcycle boot which is capable of restricting the relative movements, especially the rotary movements, between the foot and the leg to be protected. 
   The above mentioned object is achieved by a structure according to the present invention comprising: at least one leg-piece, close to and hinged on at least one heel-piece forming part of a rigid shell, characterized in that, close to the heel and between the leg-piece and the heel-piece first hinging means are provided which are angularly movable at a substantially unlimited extent as well as axially movable between two stopping means, and second hinging means which are permitted only a restricted angular movement. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     All the features and the consequent advantages of the invention will emerge more clearly from the following detailed description of some embodiment thereof and from the attached drawings in which: 
       FIG. 1  is a side elevation view of the protective part of a boot according to a first embodiment of the present invention; 
       FIG. 2  is similar to  FIG. 1  but refers to a second embodiment; 
       FIG. 3  is similar to  FIGS. 1 and 2  but refers to a third embodiment; 
       FIGS. 4 and 5  also refer to the said third embodiment and illustrate respectively a partial perspective view of the structure and a partial cross-sectional view of a bridge-piece, formed in the heel-piece, which is suitable to receive an arched tongue, connected to the leg-piece of the second hinging means; 
       FIG. 6  is similar to  FIGS. 1  to  3  but refers to a fourth embodiment; 
       FIG. 7  also refers to the said fourth embodiment and is a partial cross-sectional view of a tongue and pocket assembly, having a spherical shape, to realise the second hinging means thereof; and 
       FIG. 8  is a perspective view of a fifth embodiment in which use is made of hinging means of elastomeric materials. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In the embodiment of  FIG. 1  a structure  10 , to be associated with a motorcycling boot (not shown), consists of a leg-piece  12  connected to a heel-piece  14  by means of first rear hinging means  16  and second front hinging means  18 . The said first hinging means  16  consist of a fastening stud  20  having a shank  22 , an outer enlarged head  24  and an inner enlarged head  26 , the shank  22  passing through an axially elongated eyelet  28  provided in the leg-piece  12 . The second hinging means  18  comprise a front lug  30  in the lowermost portion of the leg-piece  12 , an associated lug  32  in the heel-piece  14  and a stud  34 , basically similar to the already mentioned stud  20 , which has a narrow shank (not shown), an outer enlarged head  36  and an inner enlarged head (also not shown). The shank of the stud  34  passes through two holes, one in the lug  32  of the heel-piece  14  and another hole  38  in the lug  30  of the leg-piece  12 . While the hole in the heel-piece  14  has substantially the same diameter as the shank of the stud  34 , the hole in the leg-piece  12  is decidedly bigger than the same shank, although smaller than the outer enlarged head  36 . As a consequence a movement is permitted of the lug  30  of the leg-piece  12  with respect to the lug  32  of the heel-piece  14  within the limits set by the mentioned difference in diameter between the hole  38  and the shank of the stud  34 . 
   It shall be appreciated that due to the first hinging means  16  any relative angular movement is allowed between an axis of the leg-piece  12  and an axis of the heel-piece  14  but only an axial movement (namely along the longitudinal axis of the leg-piece  12 ) is possible within the limits set by the elongated eyelet  28  provided in the leg-piece  12  to the travel of the shank  22  of the stud  20 . The relative angular movement between the axes of the leg-piece  12  and the heel-piece  14  is restricted by the said second hinging means  18  which only permit the shank of the stud  34  to move in the backlash between the same and the edges of the hole  38  provided in the lug  30  of the leg-piece  12 . Any relative movements in a radial direction between the first hinging means  16  and the second hinging means  18  is substantially prevented by the stud  20  which secures the heel-piece  14  to the leg-piece  12 . In this manner, in case of impacts, only restricted relative opening and closing movements of the leg-piece  12  and the heel-piece  14  are permitted, thus reducing the risk of the worst injuries which might occur to the Achilles tendon, the malleolar joints and their ligaments. 
   In the second embodiment, as illustrated in  FIG. 2 , a structure  50  to be associated with a motorcycle boot (not shown) consists of a leg-piece  52  connected to a heel-piece  54  by means of first rear hinging means  56  and second front hinging means  58 . The first rear hinging means  56  are the same as in the preceding embodiment, namely consist of a fastening stud  60  with a shank  62 , an outer enlarged head  64  and an inner enlarged head  66 , the shank  62  passing though an axially elongated eyelet  68  provided in the leg-piece  52 . As regards the second hinging means  58 , the front lug  70  in the lowermost portion of the leg-piece  52 , the associated lug  72  in the heel-piece  54 , the stud  74 , which has a narrow shank (not shown), an outer enlarged head  76  and an inner enlarged head (also not shown) also are the same as in the embodiment illustrated in FIG.  1 . Anyhow, of the two holes which are passed by the shank of the stud  74 , the hole provided in the lug  72  of the heel-piece  54  substantially has the same diameter as the shank of the stud  74 , while the second hole  78 , which is provided in the front lug  70  of the leg-piece  52  and has the shape of an oblong eyelet with the shape of an arc having a radius R and an amplitude α is longer than the said diameter. As a consequence, the second hinging means  58  allow a movement of the leg-piece  52  with respect to the heel-piece  54  along the arched hole  78 . 
   It shall be appreciated from  FIG. 2  that due to the first hinging means  56  can allow any relative angular movement is allowed between an axis of the leg-piece  52  and an axis of the heel-piece  54  but only an axial movement (namely along the longitudinal axis of the leg-piece  52 ) is possible within the limits set by the oblong eyelet  68  to the travel of the shank  62  of the stud  60 . The relative angular movement between the axes of the leg-piece  52  and of the heel-piece  54  is restricted by the second hinging means  58  which restrict the travel of the shank of the stud  74  to the angle α along the arched hole  78  provided in the lug  70  of the leg-piece  52 . Movements in the radial direction are completely prevented because the shape of the hole  78  prevents variations in the radius R of the arch A. This second embodiment of the invention proves even more effective than the first embodiment as to the limitation of the injuries which might occur to the Achilles tendon, the malleolar joints and their ligaments. 
   With reference now to  FIGS. 3 ,  4  and  5  which illustrate a third embodiment of the invention, a structure  90 , to be associated with a motorcycle boot, consists of a leg-piece  92  connected to a heel-piece  94  by means of a first rear hinging means  96  and a second front hinging means  98 . As in both embodiments already described, the first hinging means  96  consist of a fastening stud  100  having a shank  102 , an outer enlarged head  104  and an inner enlarged head  106 , the shank  102  passing through an axially elongated eyelet  108  provided in the leg-piece  92 . However, the second hinging means  98 , positioned between a lug  110  of the leg-piece  92  and an underlying lug  112  of the heel-piece  94 , consist of an arched tongue  114 , of a mean radius R, connected to the lug  110  by two abutments  116  and passing under a bridge-piece  118  obtained by an upraised portion of the heel-piece  94 , as is shown in detail in  FIGS. 4 and 5 . The bottom end  120  of the arched tongue  114 , which is thicker, prevents the tongue  114  from coming out of the bridge-piece  118 . The shape and the length of the tongue  114  allow a movement of the leg-piece  92  with respect to the heel-piece  94  along the mean line A of the tongue  114  which is restricted at the top by the abutments  116  and at the bottom by the thicker end  120 . 
   It shall be appreciated that in the third embodiment illustrated in  FIGS. 3 ,  4  and the hinging means  96  allow any relative angular movement between an axis of the leg-piece  92  and an axis of the heel-piece  94  but only an axial movement (namely along the longitudinal axis of the leg-piece  92 ) restricted by the travel of the shank  102  in the elongated eyelet  108  formed in the leg-piece  92 . The relative angular movement between the axes of the leg-piece  92  and the heel-piece  94  is restricted by the hinging means  98  which limit the travel of the arched tongue  114  to the length of the mean line A, of a radius R, defined between the shoulders  116  and the thicker zone  120 . Movements in the radial direction are completely prevented since the shape of the tongue  114  under the bridge-piece  118  prevents any variation of the said radius R. The efficiency of the third embodiment of the invention is substantially the same as the efficiency of the second one, illustrated in  FIG. 2 , as regards the limitation of the injuries which may occur to the Achilles tendon, the malleolar joints and their ligaments. However, the elimination of studs in the hinging means  98 —which may penetrate into the foot or the leg—bears the additional advantage of making the structure even safer in the event of impacts which cause the deformation of the leg-piece  92  or the heel-piece  94 . 
   With reference to  FIGS. 6 and 7  illustrating a fourth embodiment of the invention, a structure  130 , to be associated with a motorcycle boot, consists of a leg-piece  132  connected to a heel-piece  134  by means of first rear hinging means  136  and second front hinging means  138 . As in the previously described three embodiments, the first hinging means  136  consist of a fastening stud  140  with a shank  142 , an outer enlarged head  144  and an inner enlarged head  146 , the shank  142  passing through an axially elongated eyelet  148  provided in the leg-piece  132 . However, the second hinging means  138 , positioned between a lug  150  of the leg-piece  132  and an underlying lug  152  of the heel-piece  134 , are formed by an arched tongue  154 , of a mean radius R, which can be joined to the lug  150  by two widened zones  156  and inserted in a pocket  161 , which is formed inside the lug  152  of the heel-piece  134  by two adjacent walls  158  and  160  joined in a zone  162  so as to form the bottom of a pocket, as is shown in detail in FIG.  7 . 
   It shall be appreciated from  FIGS. 6 and 7  that the hinging means  136  allow any relative angular movement between an axis of the leg-piece  132  and an axis of the heel-piece  134  but only an axial movement (namely along the longitudinal axis of the leg-piece  132 ) restricted by the travel of the shank  142  in the elongated eyelet  148  provided in the leg-piece  132 . The relative angular movement between the axes of the leg-piece  132  and the heel-piece  134  is restricted by the hinging means  138  provided that during closing the travel of the arched tongue  154  is restricted to the length of the mean line A, of a radius R, defined between the two widened zones  156  and the bottom  162  of the pocket  161  of the heel-piece  134  and during opening the travel is dampened owing to the spherical curved shape of the tongue  154  which rubs against adjacent walls  158  and  160 . Movements in the radial direction are completely prevented because the shape of the tongue  154  inside the pocket under the bridge-piece  118  prevents any variation of the radius R. This embodiment of the invention is substantially as effective as the third one, illustrated in  FIGS. 3 ,  4  and  5 , as regards the limitation of the injuries which may occur to the Achilles tendon, the malleolar joints and their ligaments. In addition, the dampened angular travel during opening of the arched tongue  154  entails a gradual resistance to the opening movement instead of a harsh stop as provided by the thicker bottom end  120  of the arched tongue  114  in the previous embodiment. 
   In a final embodiment of the invention, illustrated in  FIG. 8 , which is notable because of its simplicity, a structure  170 , to be associated with a motorcycle boot, consists of a leg-piece  172  connected to a heel-piece  174  by means of first rear hinging means  176  and second front hinging means  178 . Both the rear and front hinging means  176  and  178  consist of moulded parts made of elastomeric materials to realize the connection between the leg-piece  172  and the heel-piece  174  in the region of the heel and of the inner side of the ankle joint. The restrictions to axial and angular movements of the two hinging means  176  and  178  are ensured by the physical characteristics of the elastomeric materials chosen for their construction since they able to offer a sufficient protection against injuries involving the Achilles tendon, the malleolar joint and ligaments. This construction is also remarkable for a decidedly lower cost than the four embodiments illustrated in  FIGS. 1  to  7 . 
   Moreover, it should be noted that the use of hinging means  176  and  178  made of elastomeric materials has the further advantage of not requiring any additional thicker zone on the leg-piece  172  and heel-piece  174 . Consequently, the fifth embodiment of the invention allows simplifications in the design of an inner shoe, to be positioned between the structure  170 , the leg and foot. 
   It is finally to remark that the above described embodiments of the invention shall not be considered in a limiting sense, the scope of the invention being defined only by the following claims.