Snowboard boot ankle support assembly

An ankle support assembly for use in combination with a soft-style snowboard boot. The assembly includes a rigid heel cup and a high back support for supporting the calf region of the snowboard rider. The high back support includes an extension member having a bottom end portion that is coupled within a pocket formed in the upper rear region of the heel cup. The coupling permits the high back support to float about a pivot axis that is translatable a predetermined amount along transverse, longitudinal and vertical axes of the ankle support assembly so as to enable articulation of said ankle support device in a manner that closely approximates the articulation of the foot and ankle of the snowboard rider. A tether is provided to prevent inadvertent decoupling of the high back support from the heel cup. Also included is a length adjustable tension cable to provide forward lean adjustment for the assembly.

TECHNICAL FIELD 
The present invention relates generally to improvements in soft-style 
snowboard boots of the kind that include an interface to a binding element 
affixed to a part of the boot for use in combination with step-in 
snowboard bindings. More particularly, the present invention relates to an 
internal ankle support assembly for use in combination with a soft 
snowboard boot, wherein the assembly is effective to lock out forward 
extension movement of the snowboard rider's ankles, and is effective to 
closely approximate the articulation of the foot and ankle of the 
snowboard rider. 
BACKGROUND OF THE INVENTION 
Snowboard boots generally fall into one of two categories: "hard-style" or 
"soft-style" boots. Hard snowboard boots are the preferred boot for 
downhill riding. The construction of hard snowboard boots is similar to 
that of conventional ski boots. Plate bindings are used for attaching the 
hard boots to the snowboard. 
Soft-style snowboard boots are the preferred boot for freestyle riding. The 
construction of the soft boot design is characterized by a flexible boot 
upper which permits high lateral mobility to accommodate the ankle and 
calf movement of the rider during freestyle maneuvers. Common binding 
types for attaching the soft-style snowboard boot to the snowboard include 
external strap bindings and step-in bindings. 
It is well recognized in the art that soft-style snowboard boots require 
support in the calf region in order to lock out forward extension of the 
ankle in order to facilitate tipping the board on edge when executing a 
back side or heel side turn. 
In the past, this support was provided by the high back structure of 
conventional strap bindings. The high back structure effectively locks out 
the forward extension movement of the ankle, while side-to-side rotation 
of the ankle and foot is permitted (as allowed by the flexibility of the 
boot/ankle). Without this flexibility, the rider's ability to optimally 
control board position and bodily stance is diminished. This is especially 
detrimental to "freestyle" riding, where quick turns and stunts require a 
high degree of side-to-side ankle/foot flexibility. 
In the case of step-in bindings, there is no external high back. Therefore, 
an essential feature to the design of a soft-style boot for step-in 
bindings is the relocation of the external high back support structure 
found on conventional (strap-type) bindings to the interior of the boot. 
This structure allows the rider to efficiently apply a rearward force 
(towards the back edge of the snowboard) which is critical in providing 
control while riding. The high back is fixed at a particular angle in 
relation to the board, such that a force applied "backwards" to the high 
back (relative to the boardrider), with the board pivoting about an axis 
through the heel side edge, will pull the front of the board upwards. The 
rider simply leans backwards, pushing the high back backwards, which then 
"tips" the board up onto the heel side edge. Without such a structure, the 
rider would have to pull the toe edge of the board upwards using his leg 
muscles. The high back structure effectively "locks out" the forward 
extension of the ankle. However, as the boot is not attached to the 
external high back, lateral and medial rotation of the ankle/foot is not 
inhibited by the high back. 
The internal high back support structure should provide similar 
effectiveness of ankle lock out as an external high back while also 
allowing relatively free side-to-side rotation of the ankle/foot. Thus, 
the provision of an integral structure in a soft-style snowboard boot 
which provides similar support as an external high back while still 
allowing lateral/medial flexibility would be a highly desirable feature. 
For the case of conventional strap bindings with external high back 
support, the amount of forward lean is determined by the angle of the 
external high back, which is not itself attached to the boot. Therefore, 
lateral/medial rotation of the ankle/foot does not affect the amount or 
degree of forward lean imparted by the high back, and vice-versa. Forward 
lean and lateral/medial ankle/foot rotation are effectively isolated from 
one another. Without this isolation, the rider's freedom of movement/board 
stance and degree of control are diminished. A high back/forward lean 
structure that is integral to the boot must effectively retain this 
independence between forward lean and lateral/medial ankle/foot rotation. 
From published European Patent Application EP 0 646 334 A1, there is 
disclosed a high back support insert for a soft-style snowboard boot which 
is adapted to be placed between the flexible outer boot portion and the 
soft padded inner boot portion. The insert includes a heel cup/foot bed 
portion which is pivotally connected to an upper high back portion at the 
height of the ankle about an axis extending in the longitudinal axis of 
the boot plane. A pair of lengthwise adjustable straps connect opposite 
sides of the foot bed portion (at the ball of the foot region) to 
respective opposite sides of the high back. A shortening adjustment of the 
straps provides a change in the forward lean of the boot insert by pulling 
the upper high back portion forwardly toward the toe end of the heel cup 
foot bed portion of the boot insert. 
Blax of Germany is currently selling a version of this type of high back 
soft boot insert under the name of I-SPINE. The Blax system utilizes a 
single direction tension adjustment via a ladder strap that runs 
vertically up the back of the ankle. In the Blax design, the fixed pivot 
location between the high back and heel cup means that the presence of 
high back is always "felt" by the rider. In toe side turns, the fixed 
pivot restrains the high back and does not allow it to follow the forward 
lean of the rider's ankle. In view of the fixed pivot feature, this design 
feels mechanical and limiting as it does not closely mimic the rolling 
articulation of the foot and ankle. It is noted that the ankle joint has a 
very limited amount of side-to-side angular rotation. The side-to-side 
flexibility of the ankle/foot is mostly achieved by rotation/articulation 
of the structure of the foot. 
Accordingly, an ankle support device for a soft-style snowboard boot which 
provides high back support needed for heel side turning and which also 
closely approximates the rolling articulation or the ankle and foot during 
side to side movements and toe side turning would constitute a significant 
advance in the art. 
SUMMARY OF THE INVENTION 
Briefly, the invention discloses a multi-piece support system consisting of 
a rigid heel cup, a stiff high back, and an adjustable forward lean strap 
or cable. 
The heel cup is designed with a pocket on the upper back edge into which 
fits the rounded bottom end of the high back. The bottom end of the high 
back is coupled securely within the pocket, yet is free to roll and shift 
from side to side, allowing lateral rotation of the ankle joint without 
sacrificing high back support. The high back "floats" in the pocket 
instead of pivoting about a fixed point, giving greater comfort and 
control to the rider. It also has some limited front-to-back freedom of 
rotation in the pocket, allowing forward lean adjustment. 
The adjustment forward lean strap or cable is mechanically connected at two 
points on opposite sides of the boot. It's position is also fixed relative 
to the top of the cuff/high back, but the boot cuff is free to slide along 
its length. This allows for adjustment of the cable or strap on only one 
side of the boot, and also allows greater lateral boot flexibility without 
sacrificing support. The forward lean strap system is coupled to the top 
of the high back in such a way as to transfer load from the forward lean 
strap to the high back, so that when the rider applies force backwards to 
the top of the boot (by leaning backwards for a back side or heel side 
turn), the applied force is balanced by the opposing horizontal component 
of the tension in the forward lean strap, while the compression in the 
high back balances the vertical component of the strap tension. 
Unlike the fixed pivot ankle support insert designs of the prior art, the 
free floating coupling between the bottom end of the high back support and 
the heel cup permits the bottom end of the high back to move vertically 
upwards within the pocket when tension in the straps slackens. This 
situations occurs, for example, during toe side turns where the rider 
leans forward to shift weight to the toe side edge of the snowboard. The 
free floating coupling feature advantageously allows the upper part of the 
high back support to move upwardly and forwardly as needed to more closely 
follow the complex articulation of the rider's ankle and calf region 
during toe side turns. 
The invention preferably includes restricting means for restricting the 
range of vertical movement of the high back with respect to the heel cup 
so as to prevent inadvertent decoupling of the bottom end of the high back 
from the heel cup pocket. The restricting means may include, for example, 
a tether or leash for anchoring the high back to the heel cup. Other 
solutions which provide the equivalent restricting function may include, 
but not be limited to: (1) sewing or otherwise affixing the high back to 
the boot inner liner material; (2) providing engagement or abutment 
structure (e.g. tabs, lips, stops, etc.) on mutually facing surfaces of 
the heel cup pocket and the bottom end of the high back; and (3) 
configuring the coupling between the heel cup pocket and bottom end of the 
high back as a "loose pin within a pin hole" type coupling, wherein the 
heel cup pocket includes a narrow neck and wide bottom and the bottom end 
of the high back is fashioned as a bulbous member adapted for one way 
insertion within the narrow neck so that it rides within the wide bottom 
end of the heel cup pocket. 
The heel cup pocket is preferably dimensioned to provide the bottom end of 
the high back a desired amount of translation or movement in the 
transverse (side-to-side) and longitudinal (fore-aft) directions of the 
ankle support device. The range of motion provided by the appropriately 
dimensioned pocket is sufficient to permit the pivot axis at the bottom 
end of the high back support to shift or float in the transverse and 
longitudinal axis of the boot as needed in order to more closely 
approximate the articulation of the rider's ankle during side to side 
shifting or rolling motions of the ankle. 
Methods and apparatus which incorporate the features described above and 
which are effective to function as described above constitute specific 
objects of this invention. 
Other and further objects of the present invention will be apparent from 
the following description and claims and are illustrated in the 
accompanying drawings, which by way of illustration, show preferred 
embodiments of the present invention and the principles thereof and what 
are now considered to be the best modes contemplated for applying these 
principles. Other embodiments of the invention embodying the same or 
equivalent principles may be used and structural changes may be made as 
desired by those skilled in the art without departing from the present 
invention and the purview of the appending claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
With reference to the FIG. 1, there is shown an ankle support assembly 10 
constructed in accordance with one embodiment of the present invention. 
The ankle support assembly 10 includes a rigid molded heel cup 12 with a 
slot or pocket 14 formed in the top rear surface of the heel cup. The heel 
cup pocket 14 provides "floating" support to the high back, but is also 
designed to locate and hold the heel in a fixed position, preventing "heel 
lift" which is detrimental to the control of the system. 
The ankle support assembly 10 further includes a rigid or partially rigid 
high back support 16 having a narrow, rounded bottom end member 18 adapted 
for coupled insertion within the heel cup pocket 14. Since the bottom end 
member 18 is not mechanically fixed to the heel cup 12, and since the 
pocket 14 is larger than the bottom end of the high back, the high back 16 
is free to rotate laterally (as indicated by directional arrow A) and 
shift vertically (as indicated by directional arrow B), thereby giving 
greater control and freedom of movement to the rider. The high back 16 
"floats" in the pocket 14 instead of pivoting about a fixed point. Because 
of this, the assembly 10 articulates in a manner that closely approximates 
the actual articulation of the foot and ankle, thereby providing more 
comfort and freedom than a fixed pivoting assembly. In addition, the 
movable "axis of rotation" is significantly lower than the axis of 
rotation in the fixed pivoting ankle support systems of the prior art, 
thus allowing the system of the present invention to more closely mimic 
the ankle's true action. The pocket width is also designed to be greater 
than the thickness of the bottom end 18 of the high back 16 so that some 
front-to-back rotation of the high back 16 is also accommodated (as 
indicated by directional arrow C). This allows for adjustment of the 
forward lean of the boot. 
With reference to FIG. 2, the ankle support device 10 preferably includes a 
leash 20 connected between the high back support 16 and heel cup 12 to 
restrain or limit the total upward range of motion of the high back 
support or spoiler 18. The leash 20 prevents the inadvertent decoupling of 
the high back 16 from the heel cup 12. 
With reference to FIG. 3, the ankle support device 10 may include a length 
adjustable cable or strap 22 for forward lean control. In this figure, the 
ankle support assembly 10 is shown fitted within a soft-style snowboard 
boot 23 (shown in phantom). The opposite ends of the cable or strap 22 are 
attached to the respective opposite sides of the boot upper 24 at two 
locations on opposite sides of the foot. The cable 22 is directed through 
a guide 26 that goes around rear of the high back support 16. The cable 22 
includes a length adjustable locking mechanism 28 that allows for 
adjustment of the forward lean of the boot. The above-described connection 
of the length adjustable cable 22 to the boot upper 24 and high back 16 
permits the boot cuff/high back to slide freely along the length of the 
cable 22 to allow lateral flexing about the ankle joint with no loss of 
high back support. This could also be accomplished in either of the 
following ways, each comprising a separate design. In each case the 
forward lean system and the high back would be securely connected, so that 
the vertical component of the strap/cable tension would be balanced by 
compression in the high back. 
1. Using a strap, this could be accomplished with a low profile D ring (or 
equivalent) attached to the boot cuff/high back, through which D-ring the 
strap would pass. The boot cuff would thus be supported by the strap, and 
would also be able to move laterally as the D-ring would slip along the 
strap. 
2. Using a cable, this could be accomplished using a sheath sewn into the 
top of the boot cuff, through which the cable would pass. The cable would 
thus support the cuff while the cuff would be free to slide along the 
cable. 
While we have illustrated and described the preferred embodiments of our 
invention, it is to be understood that these are capable of variation and 
modification, and we therefore do not wish to be limited to the precise 
details set forth, but desire to avail ourselves of such changes and 
alterations as fall within the purview of the following claims.