Patent Publication Number: US-6708425-B2

Title: Ski boot

Description:
The present invention relates to a ski boot, in particular for ski-mountaineering or telemark 
     BACKGROUND OF THE INVENTION 
     Ski-mountaineering boots are known to comprise a shell made of plastic material, a sole, and a shank hinged to the shell at the ankle. 
     Ski-mountaineering calls for boots capable of assuming a downhill position, in which, as with downhill ski boots, both the toe and heel portions of the boot are clamped to the ski and the shank of the boot is fixed rigidly to the shell, and an uphill or walking position, in which only the toe portion of the boot is clamped and the heel portion is free, i.e. raised off the ski, to enable the ski to be dragged as in cross-country skiing 
     A major drawback of this type of boot lies in it allowing of no change in position when skiing downhill in soft snow. 
     By way of a solution to the problem, ski-mountaineering boots have been proposed comprising a mechanism by which to rotate the shank forwards when moving diagonally downhill, so that the user&#39;s weight is shifted forwards, and to prevent rearward rotation of the shank with respect to the shell to prevent an excessively rearward position when turning. 
     Boots of this sort, however, are not rigid enough for downhill skiing on hard snow or ski tracks, by even the slightest rotation of the shank with respect to the shell making it difficult to control the ski and increasing the risk of injury. 
     Telemark skiing poses similar problems by calling for turning with the heel raised off the ski, as opposed to clamped rigidly as in conventional skiing. Known boots are normally capable of assuming an uphill or walking position without the ski, in which the shank is free to rotate forwards and rearwards with respect to the shell, and a downhill position in which the shank is locked; while other known models enable the shank to rotate slightly forwards with respect to the shell. 
     Boots of this sort therefore also fail to provide for all-round performance by being designed for specific types of snow. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a plastic ski boot, in particular a ski-mountaineering or telemark boot, designed to solve the aforementioned problems typically associated with known boots. 
     According to the prevent invention, there is provided a ski boot, in particular a ski-mountaineering or telemark boot, comprising a shell made of plastic material and having a bottom wall, two lateral walls and a toe portion; a shank hinged to said shell; and a control mechanism, located at the rear portion of the boot, for controlling the tilt of the shank with respect to the shell and comprising: 
     a first retaining portion and a second retaining portion, one of which is integral with said shell, and the other with said shank; and 
     a lever member hinged to said first retaining portion, said lever member being movable between a work position wherein one end rests on said second retaining portion to prevent rearward rotation of said shank, and a release position; 
     characterized in that said control mechanism comprises a third retaining portion integral with said second retaining portion; and an auxiliary locking member movable between a lock position connecting said lever member to said third retaining portion, and a rest position 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which: 
     FIG. 1 shows a side view of a ski boot in accordance with the present invention; 
     FIG. 2 shows a partial rear view of the FIG. 1 boot with the tilt control mechanism in a first position; 
     FIG. 3 shows a partial rear view of the FIG. 1 boot with the tilt control mechanism in a second position; 
     FIG. 4 shows a partial side view of the FIG. 1 boot with the tilt control mechanism in a second position; 
     FIG. 5 shows a partial rear view of the FIG. 2 boot with the tilt control mechanism in a third position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Number  1  in FIG. 1 indicates as a whole a ski boot, in particular a ski-mountaineering boot. 
     Boot  1  substantially comprises a shell  2  made of plastic material; a sole  3 ; and a shank  4  hinged to shell  2  at the ankle. 
     Shell  2  (FIG. 1) comprises integrally a toe portion  5 ; two lateral walls  6  forming a front opening (not shown) closed by a known tongue  7 ; and a bottom wall or inner sole  9  closing the bottom of their shell and forming a heel portion  9   a  in relief. Inner sole  9  also forms a toe flange  9   b  projecting from toe portion  5  and cooperating in known manner with a clamp on the ski (not shown). An outer sole  10  made of elastomeric material is fixed to the bottom of inner sole  9  and forms, with inner sole  9 , sole  3 . 
     Shell  2  also comprises a flexible portion  11  extending crosswise with respect to the shell, from one side to the other of sole  3 , and substantially located at the metatarsus of the wearer, i.e. close to the toe portion  5  of shell  2 . 
     Flexible portion  11  has an undulated contour defined by two grooves  12  separated by a radiused intermediate portion  12   a,  conveniently extends obliquely to follow the natural bend axis of the foot, and has one end, on the inner side of boot  1 , located forwards with respect to the other end on the outer side of boot  1 . 
     Shank  4  is connected to lateral walls  6  of shell  2  by respective hinges  13  along the transverse hinge axis of the ankle; and boot  1  comprises a control mechanism  14  for controlling the tilt of shank  4  with respect to shell  2  and located at a rear portion  15  of the boot, substantially above the heel. 
     Tilt control mechanism  14  comprises a lever  20  having a first end  22  hinged to a first retaining portion, defined by a rear projection  23  of shank  4 , by a pin  21  having a horizontal axis A crosswise with respect to boot  1 . 
     Shell  2  of boot  1  comprises a rear projection  24  spaced apart from and below projection  23  of shank  4 . Projection  24  is defined by a top surface  26  facing lever  20 , and has a rear surface with a substantially horizontal recess  28  for the purpose explained in detail later on. 
     Lever  20  is movable between a lowered work position (FIG. 1) wherein a second end  25  of lever  20  rests against top surface  26  of projection  24  to prevent shank  4  from rotating rearwards with respect to shell  2 , and a raised or rest position (FIG. 5) wherein shank  4  is fully released from shell  2 . 
     Control mechanism  14  also comprises a horizontally elongated metal ring  27 , a substantially horizontal portion (not shown) of which is housed inside a transverse through hole formed in second end  25  of lever  20 , so as to hinge ring  27  to lever  20  about an axis B parallel to axis A. 
     When lever  20  is in the work position, ring  27  can be set to a lock position engaging recess  28  to also prevent forward rotation of shank  4  with respect to shell  2 . 
     Shell  2  has a recessed rear portion  29  facing lever  20  and forming a cavity  30  with lever  20  in the work position. 
     In actual use, when ring  27  is released from recess  28 , lever  20  can be rotated about axis A from the FIG. 1 work position to the FIG. 5 raised position also permitting rearward rotation of shank  4  with respect to shell  2 . This position is conveniently used when climbing or walking. 
     When lever  20  is in the work position, end  25  rests on top surface  26  of rear projection  24 , as described above, to prevent rearward rotation of shank  4 , and ring  27  can be set either to the work position described above, or to a rest position stowed safely out of the way inside cavity  30 , as shown in FIGS. 3 and 4. 
     The FIGS. 3 and 4 position only prevents rearward rotation of shank  4 , and is therefore useful when skiing downhill in soft snow; whereas the FIG. 1 position (lever  20  in the work position and ring  27  in the lock position) prevents any rotation of shank  4  with respect to shell  2 , and is therefore particularly useful when skiing downhill on hard snow or ski tracks. 
     The advantages of the boot according to the present invention will be clear from the foregoing description. 
     In particular, the mechanism for controlling the tilt of the shank with respect to the shell provides for adapting retention of the shank to different operating conditions and types of snow, so that the boot is more versatile by not being subject to the design limitations typical of known boots. 
     Moreover, ring  27  is protected against impact or entanglement by being stowable safely inside a cavity  30  between shell  2  and shank  4 . 
     Clearly, changes may be made to boot  1  as described herein without, however, departing from the scope of the accompanying Claims. 
     In particular, lever  20  may be hinged to a first retaining portion integral with shell  2 , as opposed to shank  4 , and may cooperate with a second retaining portion integral with shank  4 ; and ring  27  may be replaced by any selectively activated auxiliary locking member between the lever and a third retaining portion integral with the second retaining portion.