Abstract:
Ski equipment that provides, preferably in combination, a toe release system for reducing the risk of knee injuries and a steering system for increasing turn performance. In the toe release system, the binding has a toe binding portion secured with a securing element at a forward position relative to a rear binding portion of the binding, and a release element that communicates with the securing element for releasing the toe binding portion in response to the application of pressure to the rear cuff of a boot secured with the binding, permitting movement of the toe binding portion away from the rear binding portion and thereby releasing a toe of the boot. In the steering system, the boot includes a tracking assembly that permits controlled flexing of the front and rear cuffs of the boot by applying forward and lateral pressure to the front cuff.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional No. 60/382,499, filed May 22, 2002. 
    
    
     BACKGROUND OF INVENTION 
     1. Field of the Invention 
     The present invention generally relates to ski equipment. More particularly, this invention relates to a ski boot and ski boot binding system that provides, preferably in combination, a toe release system for reducing the risk of knee injuries and an ankle-flex steering system for increasing turn performance. 
     2. Description of the Related Art 
     The stiffness of modern ski boots has drastically reduced the incidence of ankle injuries. For ski boots of the clam shell-type (having front and rear cuffs pivotably coupled to a foot shell), this stiffness is the result of permitting only limited lean adjustment in the forward direction and essentially none in the rearward direction. While protecting the ankle, boot stiffness places greater loads on the knee, such that sprains and tears of the anterior cruciate ligament (ACL) are now a relatively common type of injury associated with downhill skiing. One particular type of ACL injury is termed the “phantom foot injury” and involves the tail of the ski, which points in the opposite direction of the skiers” foot. A phantom foot injury occurs when the tail of the ski acts as a lever to apply (through the rigid rear cuff of the boot mounted to the ski) a forward force on the lower leg. Such a situation occurs when the skier is off-balance rearward, with hips below the knees in a squatting position. In this position, the lack of flexing of the boot rear cuff results in the tail of the ski being forced downward. The tendency is for an edge of the ski tail to “catch,” causing the ski and boot, and therefore the lower leg of the skier, to twist under load. 
     Various approaches have been proposed for avoiding this type of injury, notable examples of which include commonly-owned U.S. Pat. Nos. 4,880,251, 5,020,822, 5,026,087, and 5,412,883. The avoidance of phantom foot and ACL injuries is also the subject of U.S. Pat. No. 5,107,608 to Kreitenberg and U.S. Pat. No. 6,131,313 to Pierce et al. Each of these solutions generally involves releasing the rear cuff from the front cuff, allowing increased rearward motion of the skier&#39;s lower leg relative to the ski in order to reduce the load on the knee. While this type of safety feature is a significant improvement over conventional ski boots, further improvements are still desired to provide greater safety and comfort to skiers. 
     In addition to safety, comfort and performance are also of great interest to downhill skiers, particularly those who ski competitively. Commonly-owned U.S. Pat. Nos. 4,880,251, 5,020,822, 5,026,087, and 5,412,883 offer significant improvements in both comfort and performance, including a flexible toe that makes walking considerably easier and safer, and the ability to adjustably cant the boot relative to its binding (and therefore the ski). As with the issue of safety, further improvements in comfort and performance are also continuously sought by the skiing industry. 
     SUMMARY OF INVENTION 
     The present invention provides ski equipment that provides, preferably in combination, a toe release system for reducing the risk of knee injuries and a steering system for increasing turning performance. These capabilities are preferably, though not necessarily, incorporated into a ski boot and binding system in which the boot comprises a foot shell with front and rear cuffs attached thereto in a rigid clam shell-type construction, and in which the binding secures the boot with a toe binding portion that engages a toe portion of the boot and with a rear binding portion that engages a heel portion of the boot. 
     In the toe release system of this invention, the toe binding portion of the binding is secured with a securing element at a position forward of the rear binding portion, and a releasing element communicates with the securing element for releasing the toe binding portion to permit movement of the toe binding portion relative to the rear binding portion. The toe release system further includes an element for moving the toe binding portion in a forward direction away from the rear binding portion when released by the releasing element, thereby releasing the toe portion of the boot and allowing the toe portion to lift upward away from the toe binding portion, even if the heel portion of the boot remains engaged with the rear binding portion. In a preferred embodiment, the releasing member is operated in response to the application of pressure to the rear cuff of the boot, such as when the skier is off-balance rearward, with hips below the knees in a squatting position, such that the skier&#39;s thigh applies forward pressure to the rear cuff or a portion thereof. As such, the toe release system is well adapted to release the boot of a skier from its bindings when the skier is in a situation where a phantom foot injury is very likely to occur. 
     The steering system of this invention is configured to provide lateral movement or “flexing” of the boot relative to the binding when the skier applies pressure with both forward and lateral components (force vectors) to the front cuff. As such, the steering system is able to increase the inside turn ski edge angle simply by applying the appropriate forward pressure while turning the skis, and provides a skier with more edge holding force in a steep racing-type turn because the skier&#39;s weight is more on top of the skis. In accordance with a preferred aspect o the invention, the steering system comprises a tracking assembly located between the front cuff and the foot shell of the boot. A particular tracking assembly comprises a follower engaged with a track member having at least two tracks that diverge from each other in the lateral directions of the boot. In this configuration, the follower can be caused to track along a first of the tracks by applying pressure on the front cuff in a direction having both a forward direction component (vector) and a component (vector) in a first lateral direction of the boot, which causes the boot to flex relative to the binding in the first lateral direction. Likewise, the follower tracks along a second of the tracks by applying pressure on the front cuff in a direction having both a forward direction component and a component in the second lateral direction of the boot (opposite the first), which causes the boot to flex relative to the binding in the second lateral direction. 
     In view of the above, it can be seen that the present invention offers significant improvements over conventional ski boots in terms of greater safety with respect to knee injuries, as well as improved performance characteristics. Other objects and advantages of this invention will be better appreciated from the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side view showing in partial section a ski boot and binding system in accordance with an embodiment of this invention. 
         FIGS. 2 and 3  are plan and front cross-sectional views, respectively, of a steering system of the boot shown in  FIG. 1 . 
         FIG. 4  is a cross-sectional side view of a toe-release system of the boot shown in  FIG. 1 . 
         FIG. 5  is a cross-sectional side view of a toe-release system in accordance with an alternative embodiment of the invention. 
         FIG. 6  is a cross-sectional side view of a boot equipped with a toe-release system in accordance with another alternative embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     A ski boot and binding assembly  10  in accordance with a first embodiment of the invention is Illustrated in  FIGS. 1 through 4 , with alternative embodiments of the invention being illustrated in  FIGS. 5 and 6 . As will become apparent from the following discussion, the embodiments are depicted as combining two features of this invention—a toe release system and a steering system—though each of these features could be utilized separately from the other. 
     With reference to  FIGS. 1 through 4 , the ski boot and binding assembly  10  comprises a ski boot  12  mounted to a binding assembly  14 , the latter of which is secured to a ski  16 . The boot  12  is represented as being of the clam shell-type, and as such has a foot shell  18  and front and rear cuffs  20  and  22 . The cuffs  20  and  22  are pivotably attached to each other and to the foot shell  18  at two pivot points defined by hinges  24  located on opposite sides of the boot  12 . The rearward edge of the front cuff  20  overlies the rear cuff  22 , with the portion of the rear cuff  22  beneath the front cuff  20  being shown in phantom in  FIG. 1 . The foot shell  18  includes a toe segment  26  that extends from and is overlapped by the shell  18 . The toe segment  26  is illustrated in  FIG. 1  as being connected to the shell  18  at a living hinge  28  located in the sole of the boot  12  at approximately the location where the ball of the foot is positioned when the boot  12  is worn. In accordance with commonly-owned U.S. Pat. Nos. 4,880,251, 5,020,822, 5,026,087 and 5,412,883, the hinge  28  aids the wearer while walking in the boot  12  by providing a focal point at the ball of the foot instead of the toe of the boot, as is the case with conventional ski boots having rigid soles. Other aspects of the toe segment  26  can be found in U.S. Pat. Nos. 4,880,251, 5,020,822, 5,026,087 and 5,412,883, whose contents are incorporated herein by reference. 
     The cuffs  20  and  22  are shown as being joined by cables  30  on opposite sides thereof, one of which is visible in  FIG. 1 . The cables  30  are anchored at their front and rear extremes by a front cuff release  32  located on the front cuff  20  and a hub  34  mounted on the rear cuff  22 . The release  32  permits the boot  12  to be secured around the wearer&#39;s lower leg simply by pivoting a lever  36  downward. The release  32  also preferably enables the lengths of the cables  30  to be adjusted to provide a comfortable, secure fit to the lower leg. Other aspects regarding the manner in which the cables  30 , release  32 , and hub  34  can be constructed to secure the front and rear cuffs  20  and  22  are discussed in commonly-owned U.S. Pat. No. 5,412,883, and therefore will not be discussed in any detail here. Of significance is that the hub  34  is not required to have a safety-release feature described in U.S. Pat. No. 5,412,883, because the rear cuff  22  is not intended to be released from the front cuff  20  under conditions in which a rearward force is applied to the rear cuff  22 . Instead, the toe-release system mentioned above (and discussed in detail below) addresses this concern. However, in combination with or in the absence of the toe-release system of this invention, the boot  12  can incorporate the cable, release and hub system disclosed in U.S. Pat. No. 5,412,883, such that a sufficiently large rearward force on the rear cuff  22  causes the rear cuff  22  to be released from the front cuff  20  in order to reduce the risk of knee injury. Alternatively, the boot  12  could be modified to employ other rear cuff release systems in combination with or in the absence of the toe-release system of this invention. 
     The binding  14  is represented as comprising front and rear binding units  38  and  40  for engaging the forward-most and rearward-most edges  42  and  44  of the boot sole (near the toe segment  26  and the boot heel  46 , respectively), by which the boot  12  is secured to the binding  14 . The edges  42  and  44  are shown as integral portions of the sole of the boot  12 , though other constructions are foreseeable. The binding  14  is configured to be a “step-in” type binding, in which a skier enters the binding  14  by first inserting the forward edge  42  of the boot  12  beneath a toe-piece binding  48  of the front binding unit  38 , and then steps down on the rear binding unit  40  to cause a rear binding  41  to engage the rearward edge  44  of the boot  12 . The front and rear binding units  38  and  40  are both shown as being directly secured to the ski  16 . A smooth hard metal plate  37  is preferably mounted between the binding units  38  and  40  and rides on adjustable ball bearings  39  that eliminate lateral and forward friction that would resist release of the boot  12  from the binding  14 . The rear binding unit  40  can be of essentially any suitable design, and therefore will not be discussed in any detail here. In contrast, the front binding unit  38  shown in  FIGS. 1 and 4  is adapted to release the toe segment  26  of the boot  12  under conditions where a knee injury, and particularly a phantom foot injury, is likely to occur. 
     The front binding unit  38  includes the previously-noted toe-piece binding  48 , which has a base  50  slidably mounted to a track  52  secured to the ski  16 . As more readily seen in  FIG. 4 , the base  50  has a latch  54  pivotably mounted thereto about a shaft  55  that is transverse to the longitudinal direction of the ski  16 . The latch  54  is equipped with a spring  56  that biases the forward end of the latch  54  downward into engagement with a catch (e.g., groove)  58  in the track  52 . One or more springs  60  bias the base  50  in the forward direction relative to the track  52 , and therefore away from the rear binding unit  40 . However, the force applied to the latch  54  by the spring  56  is sufficient to prevent release and movement of the base  50  and its toe-piece binding  48  unless the forward end of the latch  54  is disengaged from its catch  58 . For this purpose, the forward edge  42  of the boot  12  is equipped with a device for actuating the latch  54 , causing the rearward end of the latch  54  to move downward so that the forward end of the latch  54  rotates up and out of engagement with the catch  58 . In the embodiment of  FIGS. 1 and 4 , the device for disengaging the latch  54  is represented as a cam  62  that, when rotated in a counterclockwise direction (as viewed in  FIG. 4 ) about its axis  63 , depresses the rearward end of the latch  54 . The resulting clockwise rotation of the latch  54  (as viewed in  FIG. 4 ) disengages the latch  54  from the catch  58 , permitting the spring  60  to urge the toe-piece binding  48  to rapidly translate forward and out of engagement with the edge  42  of the boot  12  (as shown in phantom in  FIG. 4 ). The distance the toe-piece binding  48  must travel to disengage the boot edge  42  will depend on the size and shape of the edge  42 , with a distance of about one-half inch (about one centimeter) being sufficient for many applications. The distance that the toe-piece binding  48  is permitted to travel forward is shown in  FIGS. 1 and 4  as being positively limited by a stop block  51 . 
     In the embodiment of  FIGS. 1 and 4 , the cam  62  is caused to rotate through a cable  64  that is routed through the sole of the boot  12  to a paddle  66  mounted with a pivot attachment  68  to the rear cuff  22  of the boot  12 . The cable  64  comprises upper and lower portions that can be part of a continuous cable or formed by separate cables attached to the cam  62 , so that retracting the lower portion causes the cam  62  to rotate counterclockwise, resulting in actuation of the latch  54  and release of the toe-piece binding  48 . As evident from  FIG. 1 , the lower portion of the cable  64  is attached to a portion of the paddle  66  above its pivot attachment  68 , so that the lower portion of the cable  64  is retracted rearward when the paddle  66  is rotated forward (clockwise as viewed in  FIG. 1 ) toward the rear cuff  22 . The paddle  66  is mounted to the pivot attachment  68  with a torque spring  70  that acts to rotate the paddle  66  rearward away from the rear cuff  22  (counterclockwise as viewed in  FIG. 1 ) about its pivot attachment  68 . The upper portion of the cable  64  is attached to a portion of the paddle  66  below its pivot attachment  68 , so that rearward movement of the paddle  66  causes the upper portion of the cable  64  to refract rearward, which in turn causes the cam  62  to rotate clockwise and return to its original position, such that the latch  54  is also permitted to return to its original position under the influence of the spring  56 . 
     The above-described operation of the paddle  66  is able to reduce the risk of phantom foot injury under a condition that is likely to proceed such an injury, namely, when the skier&#39;s weight is rearward and his/her hips are below the knees, placing the skier&#39;s thigh against the rear cuff  22 . With the skier in this position, the paddle  66  is depressed (rotated forward) by the skier&#39;s thigh, causing the cam  62  to disengage the latch  54  and permit the toe-piece binding  48  to shift forward and release the boot edge  42 . Once the edge  42  is clear of the binding  48 , the toe segment  26  of the boot  12  is able to rotate upward and/or laterally away from the ski  16 , thus completely eliminating the forward force on the lower leg applied by the ski tail through the rigid structure comprising the ski  16  and rear cuff  22 . 
     While a particular configuration and construction are represented in  FIGS. 1 and 4  for causing the latch  54  to release the toe-piece binding  48 , various other configurations are foreseeable and within the scope of this invention. As an example,  FIG. 6  shows the cable  64  and paddle  66  being replaced by a solenoid  164  connected to the cam  62  with a rod  165  and electrically connected with an electrical wire  167  to one or more pressure sensors  166  mounted in the rear cuff  22 . The solenoid  164  (or another suitable electromechanical device) is adapted to maintain the cam  62  in its initial fully-clockwise position under normal conditions while the boot  12  is worn, but to rotate the cam  62  counterclockwise when a sufficiently large pressure (force) is sensed by the pressure sensor (s)  166 . This embodiment of the invention further comprises a microprocessor  168  that enables the skier to adjust the load at which the solenoid  164  is commanded to actuate the cam  62 , a switch  170  that delivers the energizing signal to the solenoid  164 , and a battery pack  172  for powering the solenoid  164 , pressure sensor(s)  166  and microprocessor  168 . 
     It is also within the scope of this invention to employ toe-piece bindings that release the toe segment  26  of the boot  12  by other than a sliding operation. For example,  FIG. 5  represents a toe-piece binding  148  that is mounted to a base  150  for forward rotation about a pivot  152 , instead of being mounted to a base (e.g.,  50 ) that slides forward on a track (e.g.,  52 ). As with the embodiment of  FIGS. 1 and 4 , the toe-piece binding  148  engages the forward edge  42  of the boot  12  to secure the toe segment  26  to the ski  16 , and the base  150  is equipped with a latch  154  and spring  156 . However, the latch  154  is mounted for translational movement on the base  150  and, when in a forward position under the force of the spring  156 , engages a catch (e.g., edge)  158  of the toe-piece binding  148  to prevent forward (counterclockwise) rotation of the binding  148 . One or more springs  160  bias the toe-piece binding  148  in the forward rotational direction. However, the latch  154  is sufficient to prevent release and movement of the toe-piece binding  148  unless the forward end of the latch  154  is disengaged from the catch  158  of the toe-piece binding  148 . As with the previous embodiment, the cam  62  is adapted to actuate the latch  154 , in this case rearwardly, to cause the forward end of the latch  154  to disengagement the catch  158  on the toe-piece binding  148 . In  FIG. 5 , the cam  62  is shown as actuating the latch  154  by engaging a recess  162  in the upper surface of the latch  154 . Once the latch  154  has disengaged the catch  158 , the spring  160  urges the toe-piece binding  148  upward and out of engagement with the edge  42  of the boot  12  (as shown in phantom in  FIG. 5 ). 
       FIGS. 1 ,  2 ,  3  and  6  depict the steering system of this invention, which can be used in combination or separately from the toe-release system described above. With particular reference to  FIGS. 2 and 3 , a steering unit  74  is represented as being between the foot shell  18  and the front cuff  20  of the boot  12 . The steering unit  74  is operable to flex the boot  12  relative to the binding  14  when pressure with both forward and lateral components (force vectors) is applied to the front cuff  20 . More particularly, the steering unit  74  enables the front and rear cuffs  20  and  22  to move or flex in unison relative to the foot shell  18 , with flexing focused at a location approximately coinciding with the skier&#39;s ankles. Contrary to the limited rotational movement typically permitted between a front cuff and foot shell of a conventional clam-type ski boot, the boot  12  of this invention is adapted to permit lateral movement and twisting of the front cuff  20  (as well as the rear cuff  22  coupled to the front cuff  20  with the cable  30 ) relative to the foot shell  18  as a result of each hinge  24  being adapted to ride in a slot  86  formed in the foot shell  18 , as depicted in  FIG. 1 . 
     The steering unit  74  is represented in the Figures as providing controlled flexing of the cuffs  20  and  22  relative to the foot shell  18  through the cooperation of a toggle-type follower  76  facing a track plate  78 . The track plate  78  comprises at least two and preferably three diverging tracks  80 ,  82  and  84  that the follower  76  cams against when the front cuff  20  is forced forward relative to the foot shell  18  (as viewed in  FIG. 1 ). In  FIGS. 2 and 3 , the follower  76  is shown as being roughly W-shaped and pivotably mounted to a plate  88 , which in turn is mounted to the upper surface of the foot shell  18 . The follower  76  has a central peak  90  and oppositely-disposed flanges  92 , each of which engages one of the tracks  80 ,  82  and  84 , depending on the direction of pressure applied by the skier on the front cuff  20 . As evident from  FIG. 2 , the track plate  78  has a “neutral” zone  94  in which the follower  76  is not engaged with any of the tracks  80 ,  82  and  84 , corresponding to the absence of a forward pressure on the front cuff  20 . While the follower  76  is within the neutral zone of the track plate  78  (as shown in  FIG. 3 ), the front cuff  20  (to which the track plate  78  is attached) is able to move laterally to the left and right relative to the foot shell  18  (to which the follower  76  is attached) and as a result, because the ski  16  is fixed to the foot shell  18  through the binding assembly  14 , ski edge pressure is released by several degrees left or right, helping to prevent knee ligament strain or tear injuries if the skier has lost control of the skis. If only forward pressure is applied to the front cuff  20  (i.e., absent any significant lateral component to the pressure applied to the front cuff  20 ), the peak  90  of the follower  76  engages and follows the center track  80 , which is in the form of a V-shaped groove that is complementary in shape to the peak  90 . Under this circumstance, the front and rear cuffs  20  and  22  flex as a unit relative to the foot shell  18  in a forward direction. 
     If a sufficient amount of lateral pressure is applied (i.e., a sufficient lateral component is present in the forward pressure applied to the front cuff  20 ), the follower  76  moves in the direction of the lateral component, causing the upper edge of the flange  92  on the side to which pressure is applied to cam up against a slope  91  adjacent the flange  92 . For example, if the pressure on the front cuff  20  includes a lateral component to the left as viewed in  FIGS. 2 and 3 , the upper edge of the lefthand flange  92  cams against the lefthand slope  91 , causing the follower  76  to rotate counterclockwise. With sufficient forward pressure, the follower  76  moves forward to engage its righthand flange  92  with the lefthand track  82 , which diverges to the left from the center and righthand tracks  80  and  84 . In contrast to the center track  80 , the lefthand and righthand tracks  82  and  84  are defined by the raised portions or edges of the track plate  78 , preferably shaped to have circular cross-sections that are complementary in shape to the interior contours of the righthand and lefthand flanges  92 , respectively. As the righthand flange  92  follows the lefthand track in  FIGS. 2 and 3 , the boot  12  is caused to flex forward and leftward (i.e., a direction having both forward and leftward components) relative to the foot shell  18 , corresponding in direction to the lefthand track  82  being tracked by the follower  76 . From the above, one can appreciate that if the pressure on the front cuff  20  were to include a rightward lateral component as viewed in  FIGS. 2 and 3 , the upper edge of the righthand flange  92  would cam against the righthand slope  91 , causing the follower  76  to rotate clockwise so that the lefthand flange  92  can engage the righthand track  84  to cause the boot  12  to flex forward and rightward relative to the foot shell  18 . 
     As represented in  FIGS. 2 and 3 , the steering unit  74  of this invention can be adapted to permit the track plate  78  to be adjusted in the lateral directions, effectively canting the upper portion of the boot  12  relative to the foot shell  18 , binding  14  and ski  16 . For this purpose, the track plate  78  is shown mounted with fasteners  95  to a track base  96 , which is fixedly attached to the front cuff  20 . Lateral slots  97  defined in the track plate  78  ( FIG. 2 ) receive the fasteners  95 , and an adjustment screw  98  mounted to the track base  96  is threadably engaged with a flange  99  on the track plate  78 , so that rotation of the adjustment screw  98  causes the track plate  78  to be selectively and controllably translated in a lateral direction, depending on the direction of screw rotation. 
     In practice, flex angles of as much as fifteen degrees have been readily attainable with the steering unit  74  depicted in  FIGS. 2 and 3 . While the follower  76  and track plate  78  are depicted as being mounted to the foot shell  18  and front cuff  20 , respectively, their positions could be reversed. Furthermore, while a particular type of follower  76  and track plate  78  is shown, various other configurations for these components could be used yet still achieve the operation of the steering unit  74 , which is fundamentally to enable a skier to selectively cause the front cuff  20  to move in a lateral direction relative to the foot shell  18  by applying a forward pressure on the front cuff  20  with a lateral component in the direction the skier wants his or her boot to turn. The effect is to increase the inside turn ski edge angle, which provides the skier with more edge holding force in a steep turn because the skier&#39;s weight is more on top of the ski  16 . 
     While not discussed above, the ski boot and binding assemblies of this invention can be modified to further include conventional or otherwise known equipment for skis, boots and bindings. For example, the binding  14  can be equipped with a ski brake to inhibit the ski from traveling downhill after being released from the boot  12  by the front and rear binding assemblies  38  and  40 . Furthermore, the binding  14  is adapted to allow a skier to release the boot  12  when desired, such as by physically depressing a rearward extension of the rear binding assembly  40  on which a ski pole tip cup (not shown) is provided in accordance with conventional practice. Finally, various equivalents could be used in combination with or in lieu of the disclosed mechanical and electrical devices, e.g., the disclosed springs, levers, cams, tracks, cables, solenoids, etc. Accordingly, while the invention has been described in terms of particular embodiments, it is apparent that other forms could be adopted by one skilled in the art. Therefore, the scope of the invention is to be limited only by the following claims.