CA1076348A - Inner boot for a ski boot - Google Patents

Abstract

SKI BOOT

Abstract of the Disclosure A ski boot is constructed with a relatively rigid bottom foot enclosure, a somewhat more flexible cuff portion pivotally connected to the foot enclosure at the axis of the ankle, and an even more flexible spat portion arranged to close over the upper portion of the foot. A bottom traction surface comprised of heal and sole portions is removably connectable to the boot. The bottom of the foot enclosure and the traction element are mutually adapted to provide a variable cant for the foot enclosure with respect to the bottom of the traction element. A removable inner boot of soft cellular foam material is provided within the foot enclosure, and is slit down the front to facilitate foot entry without a tongue. The inner boot is also provided with external spacing tabs in the vicinity of the lower ankle to ensure a snug fit around the heal. The cuff portion is releasably engageable by a spring biased connector located at the back of the boot. Forward pivoting of the cuff with respect to the foot enclosure is guided by a pin extending from a wall of the foot enclosure through a slot in the cuff. This slot may be partially filled by a suitable insert to restrain backward movement of the cuff.

Description

1(~763~8 This invention pertains to ski boots and more specifically to a novel removable inner boot of improved design.
This is a division of copending Canadian Patent Application Serial number 296,517, filed on February 9, 1978.
State of the Art: Over the past several years ski boots have evolved through several stages from stif~
unlined boots of leather to the present rigid outer boots (generally of plastic) with flexible liners of various types. For use with modern bindings, it is essential that the outer boot be stiff to optimise the control effected on the skis by a skier shifting his weight or the attitude of his feet. On the other hand, the inner boot desirably provides for adequate comfort so that the skier can tolerate wearing the boots for extended periods.
Several approaches to boot construction have , been tried to achieve the desired combination of outer boot rigidity, ease of forward ankle movement and adequate comfort for the skier. Thus far, no approach has been entirely successful, although substantial progress has been made. Attendant to this progress, however, has been the introduction of certain structural problems and limitations.
For example, it has been found expedient in many instances to construct the outer boot shell from more pliable material than is desired for good control of the skis. Pliable materials permit flexture of the outer boot to accommodate forward ankle movement as the skier leans forward.
It has long been recognized that individual skiers require diffçrent adjustments or adaptation devices to ensure a proper cant between the soles of their feet and the skis. Otherwise, as the skier bends forward or hrings his knees forward with respect to the tips of the skis, his : , ;

, knees do not retain proper alignment. Conven~ionally, this problem ha~ been ~orrected ~y inserting wedges beneath the bindings of the skis. These wedges or shims effect a proper can~ selected to adjust the weight moment of the individual skier to the desirea position with respect to the skis. A skier utilizing several pair of skis, which is often done in areas where snow conditions are variable ~hroughout a season or even a day, requires customized canting of the bindings on each pair of skis Skis so adapted may not raadily be worn by any other skier who does not require the same ~anting.
~odern plastic ski boots are typically discarded when their traction surfaces become worn. Although the remainder of the boot may be in good condition, worn h~els and soles make it difficult to retain the boots in their bindings.
Inner boots have ~een sold with ski boots for many years. Some of these inner boots are constructed of microcellular foam material. Although various techniques have been used to custom fit inner boots to individual feet, the industry would prefer to avoid such techniques.
Inner boots have thus tended to fit badly in the heel region~
According to the present invention there is provided an inner boot for a ski boot including a pliable boot of resinous foam material, bifurcated at the front.
According to one aspect of the invention, the boot may be formed without a tongue, tabs being formed integral with the outer surface of the pliable boot and extending outward from the vicinity of the heel.

- 2 -~L~763~13 According to a specifi~ embo~iment of the invention, the tabs are adjacent the vicinity behind and beneath the ankle ~one.
In one embodiment of the invention, an inner liner is bonded to the inside surface of the pliable boot at the region surrounding the in~tep and ~op of the foot.
The inner liner may include a two way stretch fabri~ bonded to a closed cell foam substrate, the substrate being ~onded to the pliable ~oot.
Brief Description of the D.rawinys In the drawings, which illustrate what is presently regarded as the best mode for carring out the invention: -` FIG. l is a sida view of a ski boot in ~ully assembled condition together with an auxiliary part;
FIGo 2 is a view in partial perspective o~ the . boot o FIG. 1 as viewed from the oppos.ite side and from the rear;
FIG. 3 is a view in perspective of an inner boot of this invention;
FIG. 4 is a view in cross-section of the inner boot of FIG. 3;
FIG. 5 is a perspective view of a removable heel;
FIG. 6 is a perspective view of a removable sole;
FIG. 7 is a perspective view o~ a portion of a ski boot adapted to receive the heel and sole illustrated by FIGS. 5 and 6;
FIG. 8 is a series of views in front elevation showing several of the removable soles of FIG. 6; and FIG. 9 is a series of views in front eleva~ion corresponding to the series of FIG. 8 but showing removable J~ 3 -.: , 1(376348 heels of FIG. 5.
Description of the Illustrated Embodiment FIGS. 1 and 2 show a fully assembled ski boot including a pliable inner boot 21 of this invention within a rigid outer shell 22. The structure and operation of the outer shell has much in common with the ski boot described in U.S. Patent 3~52l~385~ issued July 21, 1970. For example, the shell 22 is comprised of a rigid foot enclosure 25 (See FIG. 7) including a pair of ankle plates 26 upstanding from and forming a portion of a bifurcated top wall 27. This top wall 27 extends between and is integral with a toe enclosure 28 and a heel enclosure 29. The bottom 30 of the foot enclosure is adapted to receive removable traction plates 35 (FIG. 5) and 36 (FIG. 6). A
separate cuff element 40 is connected to the ankle plates 26 by suitable means, such as the rivet 41 shown, approximately at the axis of the ankle of a foot positioned in the boot. Similarly, a spat 43 is fastened at one edge 44 by rivets 45 to overlay the bifurcated top wall ~0 27 of the foot enclosure 22. The opposite edge of the spat 43 may be drawn down against the foot enclosure 25 by means of a buckle arrangement 47. By so doing, the segments of the bifurcated wall 27 are drawn together to clamp the foot snugly. A decorative toe cap 48 is illustrated as a cosmetic feature fixed to the foot enclosure 22 just forward of the spat 43.
As best shown by FIG. 2, the cuff 40 is mounted to the foot enclosure 22 to pivot forward and backward with respect to the toe enclosure 28. Its travel is guided by a pair of rivets 49, 50 extending from attach-ment to the ankle pla-tes 26 through slots 51, 52 in the portions of the cuff 40 comprising, respectively, the ~7~3~
outer and inner surfaces of the boot. The outer head of rivet 50 travels in an arcuate recess 53. This arrangement avoids engagement by the rivet 50 of the corresponding member carried by its mated boot or the edge o~ the adjacent ski. The slot 52 and recess 53 correspond to elements 54, 55 of a plug 56. Certain skiers who desire to limit rearward pivoting of the cuff 40 (that is, to fix a permanent forward attitude of the cuff even when the skier's legs are straightened), may cut a desired section from the plug 56 and insert the element 54 through the slot 52 to, in effect, shorten the slot 52. Desirably, the plug 56 is inserted from inside the cuff so that it is held in place by the ankle plates 26.
A flexible element, such as the plastic-coated cable 58 shown is looped through a buckle arrangement 59 anchored to the heel enclosure 29. Although a portion of the buckle arrangement 59 may overlap the cuff 40, these two structures are connected only releasably through the cable 58. The opposite ends of the cable 58 are suspended from compression springs 60, 61 contained within hollow bosses 63 carried by the cuff 40. These bosses 63 open to the inside of the cuff 40 to permit insertion of the springs 60, 61 and threading of the cable 58 as shown. One end 58A
of the cable is adapted to receive threaded nuts 64 to hold the assembly in place. With the buckle 59 and cable 58 engaged as shown, forward pivoting of the cuff 40 works against the springs 60, 61. Proper tension can be provided by selecting springs 60, 61 of appropriate properties.
Additional adjustment can be effected by tightening or loosening the nuts 64. The buckle 59 may be operated -to release the cable 58, thereby permitting the cuff 40 to pivot with much less resistance. This unbuckled mode is of particular use when a skier desires to remove his skis 763~13 and walk in the ski boots. Ski boots without this capability are typically unyielding in the vicinity of the ankle, making normal walking difficult.
There is adjustable canting of the traction surfaces 65, 66 of the elements 35, 36 with respect to the bottom 30 of the foot enclosure 25. Although a single member could replace the elements 35, 36, it is preferred to provide separate heel 35 and toe 36 pieces as shown. Referring to FIG. 7, the bottom 30 of the foot enclosure 25 includes a structural member 67 with a tab or extension element 67A projecting beyond the heel enclosure 29. Similarly, a structural member 68 at the front of the bottom 30 carries a tab or extension element 68A projecting beyond the toe enclosure 28. The traction element 36 (FIG. 6) includes, in addition to the traction surface 66, an upper mating surface 69 adapted to mount flush against the corresponding portion 70 of the bottom, and a nose portion 71 adapted to interlock with the tab 68A. The nose 71 includes an upper surface which is ~0 substantially parallel the traction surface 66, and is spaced therefrom to constitute means for attachment (e.g., by clamping) to conventional toe binding apparatus of the type commonly mounted on "alpine" or "downhill"
skis. The traction element 35 is similarly adapted with an upper surface for mounting against the corresponding portion 74 of the bottom 30. It includes a tail portion 75 adapted to interlock with the extension 67A. This portion 75 carries an upper surface 76 substantially parallel the traction surface 65 and spaced therefrom to constitute means for attachment to conventional heel binding apparatus.
Various expedients for interlocking the nose 71 and tail 75 portions to the extensions 68A, 67A may be devised, but 1~76348 as illust~ated, a recess 80 in the nose 71 beneath the surface 72 fits snugly over the extension 68A so that forces on the surface 72 are translated to the foot enclosure 25 through the extension 68A. Similarly, the recess 81 fits snugly over the extension 67A so that forces on the surface 76 are translated to the foot enclosure 25 through the extension 67A.
With the traction elements 35, 36 fastened to the ski boot shell 22, and both of these elements anchored to a ski with conventionàl bindings, the traction surfaces 65, ~6 are either flush against the top surface of the ski or separated by only a thin plate constituting a portion of the binding apparatus. In any event, if the skier has e~actly the right anatomical characteristics, when he stands erect, his weight should be transferred straight dowm from the soles of his feet to the skis. In fact, very few skiers possess these characteristics. Ihus, shims or cants are often placed beneath ski bindings to rotate the traction surface of conventional ski boots, and incidentially the soles of the skiers feet, slightly (typically about 1 to about 5) around an axis parallel the lon~itudinal axis of the skis. In this fashion, the vertical moment of the skier's weight over each foot may be adjusted to directly above (or at least very near) the desired region of the ski. The present invention accomplishes the same purpose, but avoids the use of shimed bindings, while maintaining the traction surfaces of the boots in contact with or parallel the upper surfaces of the skis.
3n FIGS. 8 and 9 illustrate a feature, which is also disclosed and is claimed in copending Canadian Patent Application Serial number 328,~27, filed on May 25, 1979, as it pertains to selectab]e precanted construction.

, .. . . .. .

1~763~3 Eac~ of these figures shows a series of either toe pieces 36 (FIG. 8) or heel pieces 35 (FIG. 9) with the mating surfaces 69, 73, respectively, prebuilt te.g., by injection molding) or machined to a specified cant ang]e.
The several views of FIGS. 8 and 9 are correlated. Thus, FIGS. 8a and 9a illustrate the elements 35, 36 at 0 cant;
i.e., the surfaces 69, 73 are parallel the respective traction surfaces 66, 65. FIGS. 8b and 9b illustrate a slight cant in one direction (toward the inside of the left boot) while FIGS. 8e and 9e illustrate a slight cant in the opposite direction. The cant angle may be defined as the included angle between the surface plane 69 or 73 and a reference line A included in a plane parallel the traction surface 66, 65 as 63~

sho~rl ~s is ap~ reJIt ~rom thc dra-~ings, tl~e rcmaining vicws of FIGS, 8 nnd 9 illustratc corrcsl)on~ling clemcnts cantc-l to gr~atcr degrccs. Tlle sQries o canted sl~rfaces may be stan-~ar~ized ~ccordin-r to an ar~itrary sc~le whicll morc or less conor~s to th~t currently~ a~l~lie~ the art to bin~inE shims.
A use~ul sucl~ scale is se~ ~o~th in the following table.
~ie~ rom PIGS. 8 and 9 Can~ ~o, DlrectionCant Angle a O ~ Oc b 1 in 1-1/2 c 2 in 3 d 3 in 4-1/2 e 1 out 1-1/2 2 ou~ 3~
ou~ 4-1/2 O~ course, it is possible to provide other cants ~ithin ~ho series, either wit~lin the 4-1/2 in, 4~ out rallge stlown or to extend the range, although cants greater than about ~ are rarely required. Tn general, the precise cant re~uired for a particular skier is determined either electronically or mechanically, e.g., by means of conven~ional equipment generally available to pro ski shops for selecting binding slliss. Different cants msy be required for each of a pair o s~i boots. The proper set of precanted heel and toe pieces ~ay be selected from a stock of parts based on these measurements, or the proper cant may be applied to the suraces 69, 73 by either stock removal or stock addition me~l~ods.
Reerring again to FIGS. 8 and 9, cants are pre~era~ly structured as a ramped surface atop the normal uncanted mounting surfaces 69, /3 of FIGS. 8a and 9a. For example, comparing FIGS. Ba and 8d, the di~nension B is the thic~ness of the ~rac-tiOII element 36 measured between the traction surface 66 and the uncante~ mounting surface 69, To effect a cant, one edge B5 is ~uilt up to an increased t}~ic]~ness C. A corresponding ~7 ~3~ ~
anlount o~` material is renlovc~ from the surface ~6 so tllat ~]~e proper di~ensi.ons of the slo-t 80 are maintainecl. r~eduction o the t~licl~ness o~ the ovcrla~ 87 above the slo-t 80 is not detrimental ~ecause the ~orce o~f the ski bincling is tr~nslatcd to the toe extension 68A putting th.e overlap 87 into compression The function of the overlap 87 is ba$ically to hold *he dimen-sions o the nose 72 to a standard ~ithou~ regard to the cant bUi~t into the ~raction element 3G. ~xactly ~he sa~e consider-ations hold true with respect to the traction element 35.
Optimum comfort and durability is buil~ into the outer shell through correlation o the properties of the mate-rials of collstruction selected for the various components of the boot. As general guidelines, the traction elements 35, ~G should be of suitable composition to cushion an~ absorb the shocks o walking while offering good wear characteristics.
The spat ~3 is selected from tlle softest (or most ~lial~le) material that can be tolerated consistent wîtll the requirements o ~oot ~ear to permit deforma~ion and 1exure as the cuff 4Q pivots or~ard into contact Witll the spat. tThe toe cap 47 may coveniently be of the same material as the spat 43.~
The cuff 40 should also be flexible, but cannot tolerate as mucll stretch as may the spat 43. The cuf 40 is wrapped around ~he front of tlle boot and must maintain a firm pressure a~ainst the front of the inner boot 21 The foot enclosure 25 is intended to be as rigid as practicable, evidencing substantially no flexure, but it should not be brittle. This me~ber providcs lateral stif.fness to the boot by virtue of the ankle plates 26 and translates foot motion and pressure to the skis.
Altllough various materials of construction may be selecte~, a suitable boot can be made by injection molding th.e various com~ollelltS fror.l ~olyure~llanc formulations dcsigncd to ~roducc ~arts of spccificd "~uromc~er"~ Durome~er ~C~763~8 measurements are routinely reported in the technical literature and the specification manuals of resin suppliers.
Durometer values are reported numerically, followed by a designation of the scale upon which the number is signif-icant. For example, a Durometer value of 50D (50 units on the D scale) is actually "higher" (reflecting less compression set) than a Durometer value of 90~ (90 units on the A scale). The preferred Durometer values for components of the present ski boot are approximately 50D for the traction elements, 45D for the spat, 55D for the cuff and 77D for the foot enclosure. Suitable formulations available from the Upjohn Company of Kalamazoo, Michigan, under the Trade Mark "Pellethane"
are recipe nos. 2102-9OA (for spats), 2102-55D (for cuffs), a 50 percent by weight admixture of the two (for traction elements) and a mixture of about 70 percent by weight 2102-80DY~ and about 30 percent by weight 2102-65DX
(for the foot enclosure).
The above-identified ski boot structure including the rigid foot enclosure, cuff portion and spat portion is also disclosed and is claimed in above-identified parent application Serial number 296,517, filed on February 9, 1978.
The inner boot 21, as illustrated by FIGS~ 3 and 4, opens at the front with an outer flap 90 adapted to seat into a recess 91 provided in an inner flat 92. The inner boot 21 thus avoids the use of a separate tongue and provides a substantially continuous smooth inner surface against the front of the skier's leg. A heel tab 93 is carried on each side of the inner boot 21 behind and below the region 94 adjacent the ankle bone. These spacers urge the inner boo-t walls in toward the foot of the skier ensuring a snug Eit in the vicinity of the heel 1~7634~
without resort to special custom fitting procedures.
The inner boot 21 comprises a pliable, semi-resilient boot 95 of padding material, such as polyurethane microcellular foam. It preferably includes a wear-resistant inner liner 96. Ideally, the inner liner 96 is formed as a sock constructed of "wet suit" material, e.g., a two-way stretch fabric 97, usually nylon, bonded to a foam closed cell backing 98. Typically, the inner liner 96 will lack portions of the toe 99 and heel 100.
The preferred method of manufacture of this component is to place the inner liner 96 over a mandrel, and to foam the microcellular ~oot 95 in place over the mandrel.
This procedure ensures a permanent mechanical bond of the foam backing 98 to the boot 95 with the liner embedded flush with the adjacent inner surface 101 of the foam boot 95.
Reference herein to details of the illustrated embodiment should not be taken as limiting the scope of the appended claims. The claims themselves recite those features regarded as essential to the invention.

Claims (4)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An inner boot for a ski boot comprising:
a pliable boot of resinous foam material, bifurcated at the front and without a tongue; and tabs integral with the outer surface of said pliable boot and extending outward from the vicinity of the heel.

2. An inner boot according to claim 1 wherein said tabs axe adjacent the vicinity behind and beneath the ankle bone.

3. An inner boot according to claim 1 including an inner liner bonded to the inside surface of said pliable boot in the region surrounding the instep and top of the foot.

4. An inner boot according to claim 3 wherein said inner liner is comprised of a two-way stretch fabric bonded to a closed cell foam substrate, said substrate being bonded to said pliable boot.