Ski boot

A ski boot has a cuff pivotally connected to its lower shell member and a latch mechanism for holding the cuff in a predetermined angular orientation with respect to the shell member. The easily operated latch mechanism comprises a toggle linkage whose actuating lever is pivotally connected to the cuff within a window formed within a reinforcing rib along the spine of the cuff and connected to an articulation between a pair of links which can be swung to either side of a metastable position by the lever.

FIELD OF THE INVENTION 
Our present invention relates to a ski boot and, more particularly, to a 
ski boot of the hinged type having a sole member engageable by the ski 
binding and encompassing for the most part the foot of a skier below the 
ankle joint and a cuff enclosing a portion of the lower leg above the 
ankle joint and hinged to the lower member of the boot while being 
connected therewith by a mechanism holding the cuff in a predetermined 
orientation relative to the lower member about the common pivot. 
BACKGROUND OF THE INVENTION 
Articulated ski boots having upper and lower members pivotally connected 
together at a hinge-type joint substantially in the region of the ankle of 
the user have been proposed to allow increasing skiing flexibility since 
they permit adjustment of the angle at which the cuff holds the inferior 
or distal extremity of the leg relative to the ski to which the lower 
member is secured. 
The boot generally comprises a casing formed from the two enclosures 
previously described, which can be relatively rigid shells and a lining 
which can be applied to a sock and/or can be previously fitted into the 
casing part and composed of a relatively thick, yieldable, formfitting and 
flexible material, e.g. a synthetic-resin foam. 
The locking means for securing the cuff at a predetermined orientation to 
the lower casing member or sole piece of the boot is generally provided 
along the rear thereof in the region (spine) of the boot paralleling the 
Achilles tendon of the skier and may be adjustable and/or releasable. 
Swiss Pat. No. 518,071, for example, shows a ski boot of which the latter 
locking device is of a particularly simple type since it is constituted 
basically by a metal tongue rigid with the upper member of the cuff of the 
boot and presenting a lug adapted to be introduced into a receiving 
element fixed to the lower member or sole piece of the boot. 
The lug or projection can engage any one of a number of seats provided at 
different levels and adapted to be locked selectively at these levels to 
secure the upper member of the boot at a particular selected angle with 
respect to the lower member. 
A somewhat more complex configuration has been shown in Swiss Pat. No. 
512,204. Here the locking device comprises a piston assembly coupling the 
upper and lower parts of the boot and in which the friction stroke is 
limited by an adjustable means. 
Still another arrangement for bracing the cuff or upper member with respect 
to the sole piece or lower member of the boot casing is found in Swiss 
Pat. No. 519,970, in which the lower tongue projects upwardly into a flat 
socket of the upper member receiving said tongue and the two are locked 
together by a bail passing through holes or bores of the tongue. 
Swiss Pat. No. 623,209 abuts a mechanism on the upper member against a 
portion of the ski binding or latches the upper member relative to the 
lower member by a latching mechanism swingable about the pivot between the 
upper and lower casing member and braced, in turn, upon a portion of the 
binding. 
In Swiss Pat. No. 611,496, mechanisms are described for adjusting the 
location of the pivot and include a tension member reaching toward the 
back of the ski boot. 
In French Pat. No. 1,472,863 another tension system reaching below the boot 
has been shown, this arrangement utilizing an elastic band connecting the 
cuff with the sole portion of the ski. 
French Published Application No. 2,491,304 describes a tongue and socket 
connection between the pivotal upper member and still another member of 
the cuff. 
German Open Application No. 1,805,251 provides a ratchet arrangement in 
which a pivotal pawl has a tooth which engages in teeth provided in the 
lower member and braced against the upper member or connected thereto. 
The ski boot of the published PCT application corresponding to the 
International Publication No. WO 81 01644, in which U.S. Pat. No. 
3,561,139 was cited, describes a ski boot in which the cuff assembly is 
coupled to the lower shell member by an adjustably located pivot utilizing 
various slot configurations. 
From the foregoing summary of the state of the art known to applicant at 
the time this invention was made, it should be apparent that a wide 
variety of mechanisms has been proposed for adjusting the orientation of 
the cuff or upper shell member on the lower shell member or sole piece of 
the boot. 
These mechanisms can be divided basically into a small number of 
categories. In the first category are those which adjust the position of 
the pivot. These systems have the disadvantage that they cannot always 
effectively brace the cuff member with respect to the lower shell member 
in a fixed position of a pivot, so that the skier must either be 
uncomfortable or must readjust his boot in an inconvenient way. 
A second group utilizes bracing systems for the upper cuff member which 
depend upon the binding and are particularly prone to problems arising 
from the accumulation of snow on the binding. 
A third group utilizes catches and releases on the back or underside of the 
boot of a type which requires these releases to be exposed to the elements 
and to therefore become packed with snow and ice to make their use 
difficult. 
Finally, there are systems which, although apparently simple, do not permit 
setting of the angle satisfactorily. 
OBJECTS OF THE INVENTION 
It is, therefore, the principal object of the present invention to provide 
an improved ski boot which overcomes the disadvantages of these earlier 
systems. 
A more specific object of the invention is to provide a robust, reliable, 
easily manipulated mechanism for setting the inclination of a cuff to the 
lower shell member of a ski boot. 
It is also the object of the invention to provide a ski boot of the hinged 
type which has a mechanism for setting the inclination of the cuff 
relative to the lower shell member and which is not readily contaminated 
by snow or ice and, if contaminated, can nevertheless be readily 
manipulated. 
SUMMARY OF THE INVENTION 
These objects and others which will become apparent hereinafter are 
attained, in accordance with the present invention, in a ski boot which 
comprises a lower shell member or sole piece which can be provided with 
the formations necessary to releasably secure the ski boot on the ski 
binding, a cuff or upper member pivotally connected to the lower shell 
member about a horizontal axis located generally in the region of the 
ankle joint of the user, and locking means interconnecting these two 
members along the back or spine of the ski boot and adapted to impart a 
predetermined adjustable inclination to the axis of the cuff relative to 
the lower shell member in a locked position. 
According to the invention, the locking means comprises first and second 
links articulated to one another about a first pivot axis, one of these 
links being pivotally connected to the cuff about a second axis parallel 
to and spaced from the first pivot axis and the other link being pivotally 
connected to the shell member of the boot about a third axis parallel to 
the first and second axis and all three axes being parallel substantially 
to the pivot axis by which the upper or cuff member is pivotally connected 
to the lower or shell member. The first pivot axis, therefore, lies 
between the second and third pivot axes. 
An actuating lever is part of the toggle linkage formed by the two links 
and is provided to swing them about the second and third axes 
respectively, this lever being preferably pivotally connected to one of 
the members independently of the first, second and third axes, i.e. at a 
fourth pivot axis, and having a free end such that, when the free end is 
pressed toward the boot, the linkage locks the two members together and 
when the free end is swung away from the boot the linkage assumes another 
nonlocking position spaced from the first position and in which the two 
members are not locked together. Of course, the lever can be one of the 
links. 
According to the invention, stop means is provided on one of these members 
in the angular trajectory of at least one abutment member kinematically 
rigid with one of the links in such manner as to preclude any angular 
displacement of the linkages, when the links are in a locking position. 
According to the invention, moreover, elastic means is provided to bias the 
abutment into engagement with the stop means and thus in a manner tending 
to maintain the two members locked together. 
According to a feature of the invention, the actuating lever is pivotally 
connected to the linkage at the first pivot and is positioned so as to 
actuate the linkage in the manner of a toggle, i.e. by swinging this first 
pivot through a metastable position in which it lies in a plane defined by 
the second and third pivots to a locking position in which the first pivot 
is disposed between the wall and the spine of the boot. In the unlocking 
position the first pivot lies to the side of this plane which is opposite 
the spine of the boot. 
According to yet another feature of this invention, at least one of these 
links is a link of adjustable length, i.e. can comprise a screw threaded 
into a nut. One of these threadedly interconnected elements can thus be 
articulated to the other link at the first pivot, while the other threaded 
element is provided with the respective pivot (second or third pivot) to 
the corresponding member (cuff or sole piece). 
Both the second and third pivots, or at least one of them, can be formed in 
a hook or notch portion formed on the respective member, enabling the 
pivot to be withdrawn from the hook for complete release of the respective 
member by the locking device. Furthermore, we have found it to be 
advantageous to provide the fourth pivot, i.e. the pivot between the 
actuating lever and its member, preferably the cuff, so that it is 
coplanar with the second and third pivots.

SPECIFIC DESCRIPTION 
The ski boot according to the invention, only a portion of the rear of 
which is visible in FIGS. 1, 2 and 4, comprises, as is conventional, a 
lower shell member 1 which is also referred to as the sole piece because 
it is provided with a sole 2. The shell member 1 is also provided with 
formations, e.g. a ledge 2a at the heel of the boot, which can be engaged 
by the heel clamp or cable of the ski binding. Corresponding formations 
are also provided at the toe of the casing for engagement with the toe 
clamp of the binding and the upper of the casing can have ledges or the 
like enabling the foot of the skier to be secured in place after he has 
drawn onto his foot the customary sock. The boot is also equipped with a 
cuff or upper member 3 which likewise can be closed around the lower limb 
of the skier. 
This tubular cuff is pivotally connected to the lower member 1 by pivots 4 
on opposite sides of the boot and defining a horizontal pivot axis 
substantially in the region of the ankle pivot of the skier. 
The back of the upper member 3 is reinforced by a ridge 3a which extends 
along the spine of the boot and, at its lower part, is cut away to provide 
a window 5 defined between a pair of flanges 3b. The locking device 
represented generally at 6 is disposed within the window 5 and serves to 
lock the upper member 3 in a selected angular position with respect to the 
lower member 1. 
This locking device comprises three links 7, 8 and 9 and forms a toggle 
linkage. 
The first of these links 7 is an actuating lever which, except for its 
outwardly turned end 7* (see FIG. 4), practically completely closes the 
opening or window 5 when swung inwardly into the position shown in FIG. 2. 
This actuating lever 7 is pivotally connected at its upper end, e.g. by the 
pivot pin 10 to the upper member 3 at the rib 3a. As can be seen 
especially from FIG. 3, the upper member is formed with a stirrup 11 which 
has a pair of wings 11c and 11d projecting outwardly from parallel flanges 
11a and 11b of the stirrup 11. These flanges are connected by a web 11g 
and have holes 11h (FIG. 1) only one of which has been shown to receive 
the pin 10. The wings 11c and 11d are fixed by rivets 12a and 12b (FIG. 3) 
to the rib 3a which, in turn, is molded as part of the cuff 3 previously 
mentioned. 
At its upper end, the lever 7 is also provided with a pair of flanges 7c 
only one of which can be seen in FIG. 1 which also engages the pin 10. In 
the kinematic diagrams of FIGS. 5a through 5c, the pivot axis defined by 
the pin 10 for the actuation lever 7 is located at A, A', or A". 
Thus, the stirrup 11 projects into the window 5 and forms the support on 
the cuff member 2 for the pivots which are located on this cuff. 
At a central portion along its length, the lever 7 is provided with a pair 
of eyes 7a and 7b forming a support for a pivot pin 13* of a head 8a 
formed at the end of a threaded screw 8b. This threaded screw is 
adjustably received in a nut 8c fixed at the upper end of a channel 8d 
whose U-section provides a pair of flanges which carry a pivot pin 8e 
(FIGS. 1 and 4). The elements 8a to 8e form the link 8 which is connected 
by the third pivot to the casing member 1 in a manner which will be 
described, the first pivot of the toggle being formed by the pin 13*. 
As also can be seen from the FIGS. 1 and 4, this link 8 can be inserted 
into pair of eyes 13a, 13b and a pair of links 14a and 14b lying adjacent 
one another, these eyes being provided on a pair of U-profiles 13 and 14 
respectively. The eyes which open outwardly and thus constitute hooks or 
notches as previously described from which the pin 8e can be resiliently 
withdrawn or into which the pin 8e can be resiliently inserted, thus 
forming means for securing the lower or third pivot to the shell member 1. 
The U-profiles 13 and 14 are fixed to the lower member 1 of the boot by a 
rivet 15. 
The notches 14c and 14d have openings corresponding to the diameter of the 
pivot plane 8a while the notches 13c and 13d have openings slightly less 
than this diameter. The profile 14 is composed of a relatively rigid 
material such as a metal, aluminum or a stainless steel such as inox, for 
example, while the profile 13 is composed of a more resilient and flexible 
material such as a synthetic resin. Thus member 13 provides a spring force 
which retains the pin 8e in the notches while member 14 provides the 
strength necessary to resist any force tending to extract the pin 8e in a 
direction parallel to the plane of the linkage, the notches being opened 
outwardly, transversely to this plane. 
By threading the screw 8b further into or out of the nut 8c, the effective 
length of the link 8 can be varied and hence the angle of the cuff can be 
adjusted. 
The link 9 is articulated to the link 8 by the pin 13* and, at its end 
opposite the pivot 13*, is pivotally and slidably connected to the stirrup 
11. 
More particularly, the link 9 is provided at this end with a further pivot 
pin 9a (second pivot) which can slide (FIGS. 1 and 4) within vertical 
notches 11e, 11f formed in the flanges 11a and 11b of the stirrup 11. 
Washers 9b of an appropriate synthetic-resin material, for example, Delrin 
or Nylon, center the link with respect to the lateral faces of the flanges 
11a and 11b of the stirrup 11. 
The links and thus the moments of inertia of the three links 7, 8 and 9 are 
selected such that the resistance of yielding of the links 7 and 8 is 
substantially greater than that offered by the link 9 for the same type of 
action. 
The resiliently deformed link 9 thus functions as a somewhat flexible 
member which can act as a spring or elastic means. 
The upper ends of the notches 11e and 11f, in which the pivot pin 9a can be 
seated to define the second pivot axis D (see FIGS. 5a, 5b, 5c), are 
located at a distance from the pivot rod 13* slightly less than the 
distance between the upper stop of the pivot axis 9a of the link 9 and the 
same pivot 13* when the toggle assembly is in a condition of metastable 
equilibrium in which all four axes, defined by the pivots 10, 9a, 13* and 
8e are coplanar. 
In this position the link is somewhat bent or deformed in a force-storage 
position to enable the toggle to spring into either of its stable 
positions with the pivot 13* lying at its side of this common plane which 
has been designated as the y--y plane in FIG. 5a, for example. 
Consequently, this link 9 forms a spring tending to bias the toggle 7, 8 
into its locking stable position (FIG. 2) or its unlocking stable position 
(FIG. 4) from the metastable position shown in FIG. 5a. In the locking 
position (FIG. 2), the cuff 3 is held angularly in position about the 
pivot 4 which has been preselected by the adjusted length of the link 8. 
To appreciate the various positions of the linkage of the invention, 
reference may be had to FIGS. 5a, 5b, 5c in which the links 7, 8 and 9 are 
represented simultaneously by a dashed line 7', a dot-dash line 8' and a 
solid line 9', respectively. 
The first axes in these FIGS. are represented by the points B, B', B" while 
the second and third axes are represented by the points D, D', D" and C, 
respectively. 
The lever axis is represented at A, A', A". In each case, the articulation 
axis 4 between the upper member 3 and the lower member 1 of the ski boot 
is represented by the points E.sub.a, E.sub.b and E.sub.c in FIGS. 5a, 5b 
and 5c, respectively. 
In these FIGS., one can also see arcs R.sub.EA and R.sub.ED, respectively, 
designating the circular trajectories for the points A and D upon tilting 
of the upper member 3 relative to the lower member 1 about the axis 4, 
both the latter axis and the point C being assumed to be fixed relative to 
the ski. 
The reference character R.sub.C indicates the circular trajectory of the 
point B upon tilting of the lower link 8 about its articulation point C 
(see FIGS. 5b and 5c). 
The hatched portion 11e,f represents the upper extremity of the notches 11e 
and 11f formed in the stirrup 11 and against which the pivot 9a of the 
upper link 9 comes to rest when the toggle is in its metastable position 
and the pivot axes A through D are coplanar (FIG. 5a). 
The hatched portion indicated by the reference numeral 1' corresponds to 
the part 1* forming the spine of the lower member 1 against which lugs 7a 
and 7b of the lever 7 come to rest in the locking position shown in FIG. 2 
FIG. 5b corresponds essentially to the position shown in FIG. 1. A 
deadcenter or metastable position at the plane y--y in this figure can be 
traversed by the pivot B' when the lever 7 is shown in the clockwise sense 
abouts its pivot A to thereby rotate the link 8 in the counterclockwise 
sense and the link 9 in the clockwise sense. Since the link 8 is not 
axially compressed, the pivot D is first raised until it comes to rest at 
the abutment 11e, f, thereby compressing the link 9. As the lever 7 
continues its movement, it carries the pivot B' past the deadcenter or 
metastable position where the resistance by relaxation of the force 
storing spring 1 is held against further movement by the abutment 1'. 
This, of course, locks the assembly. 
In the position shown in FIG. 5b, however the cuff 3 is not locked, i.e. it 
can pivot more or less freely about the axis 4. 
In the unlocked position of FIG. 5b, until the lower pin 8a is released, 
the upper cuff can swing about the axis 4 as represented, for example, by 
the angle separating the plane y--y from the plane y'--y'. To increase the 
angle it is merely necessary to swing the lever 7 in the counterclockwise 
sense by manual action upon the upturned tongue 7. In this case, the link 
8 (represented by the line 8) pivots about the axis C of the pin 8e as the 
pivot 10 of the lever moves along the path R.sub.EA a circular arc 
centered upon the axis E.sub.b corresponding to the pivoting axis of the 
cuff. Simultaneously, the link 9 will be entrained by the pivot axis 13* 
along the trajectory R.sub.C centered on the pivot axis C while the second 
pivot axis D' moves along the path R.sub.ED centered at E.sub.b. The 
latter movement corresponds to an axial displacement within the grooves 
11e and 11f. 
In practice, the extreme position into which the cuff can be tilted when 
the latch is open is a function of the respective length of the three 
links 7, 8 and 9 and thus the metastable kinetic relationship of these 
links in FIGS. 5a through 5c. Of course, since the link A is of a variable 
length, this position can be varied by the user to obtain the degree of 
mobility for the cuff which he desires. 
In the locked position of FIG. 5c the angular displacement is limited to 
the angle .alpha.. 
More specifically to lock the upper member or cuff 3 in the position for 
securing, the lever 7 is approximated to the spine of the boot, i.e. shown 
in the clockwise sense to carry the pivot 13* the metastable position of 
FIG. 5a into the other stable position of FIG. 5c in which the spring 
force generated by the link 9 holds the pivot B in its position B" against 
the abutment 1'. Here again, at least initially the pivot 9a is seated at 
the top of the grooves 11e and 11f, thereby producing the elastic action 
of the link 9. As the pivot 13* swings past the plane y--y, the toggle 
jumps into the position shown in FIG. 5c. 
The maximum displacement in the direction of arrow F.sub.2 is limited by 
the engagement of the lugs 7a and 7b of lever 7 with the stop 1* (see FIG. 
2). This position corresponds to the contact of the point 13 at B" with 
the hatched zone 1' in FIG. 5c. 
During the limited tilting movement of the cuff which this locked position 
can permit, the points A and D can swing along the trajectories R.sub.EA 
and R.sub.ED centered upon the axis E.sub.c. 
Angle .alpha. representing the maximum angular excursion of the cuff in the 
locked position can be selected to suit the needs of the skier by 
adjustment of the effective link of the link 8 in the manner described. 
It is noted that whether the force on the cuff is applied rearwardly (arrow 
M.sub.1) or forwardly (arrow M.sub.2) the effect on the linkage is to urge 
the point B further into contact with the surface 1' and thus the faces of 
the cuff tend to keep the latch closed. 
In order to release the linkage it is merely necessary to swing the tongue 
7* outwardly (arrow F.sub.3 in FIG. 2) whereupon the spring force will, as 
the pivot 13* swings past the plane y--y, cause the latch to jump into its 
open or unlocking position. 
The device is thus easily operated, is reliable, does not self-release and 
is not susceptible to opening because of the accumulation of snow or ice 
and does not become more difficult to open because of such accumulations. 
The pivots composed of Nylon or Delrin remain easily operable under all 
conditions and the unit can be actuated readily even by a user wearing 
gloves or mittens.