US3367672A - Safety ski binding - Google Patents

Description

Feb. 6, 1968 J. A. TONOZZI ETAL SAFETY SKI BINDING 2 Sheets-Sheet 1 Filed July 11. 1966 /M// 70/?5 JosEPHA 70/v0zz/ 46; ENJ'HANHOL 72m Aime/VH5 United States Patent i 3,367,672 SAFETY SKI BINDING Joseph A. Tonozzi, 153 Taylor Ave., Fort Snelling, St. Paul, Minn. 55111, and Jasper Glen Shanholtzer, 9270 W. 22nd Lane, Minneapolis, Minn. 55426 Continuation-impart of application Ser. No. 490,541, Sept. 27, 1965. This application July 11, 1966, Ser. No. 565,357

8 Claims. (Cl. 280-1135) ABSTRACT OF Til-IE DISCLOSURE A safety binding adapted to be afiixed to a ski to permit secure binding of a ski boot to the ski where the binding comprises a boot engaging member afiixed to the ski for shiftable movement thereon and which has a release position and a secure position relative to the boot, further characterized by an electrically actuated release mechanism mounted on the ski and cooperating with the boot engaging member to shift the boot engaging member from a secure to a release position. The foregoing mechanism. is in close combination related to a circuit means connected to the electrically actuated release mechanism and a switch member mounted upon the ski and actuated either by predetermined tilting of the ski on transverse and/or longitudinal axis or by application of predetermined pressure of the ski boot in the binding to cause release of the boot engaging member from the secure position.

This application is a continuation-impart of our copending application entitled, Improved Safety Ski Binding, S.N. 490,541 and filed Sept. 27, 1965, and now abandoned.

This application relates to a safety ski binding and more particularly relates to a safety binding which has an electrically actuated release responsive to a predetermined pressure on the binding or a predetermined position of the binding.

Safety bindings, presently available, release the skiers foot from the binding when a preset pressure has been reached. This pressure on the binding typically comes about when the skier falls. However, sutficient pressure to release the binding may be placed on the binding during turning maneuvers of a skier. To provide against this happenstance, many skiers preset the release pressure on the ski bindings to a pressure well past any pressure which may be exerted on the binding during typical skiing maneuvers. In many instances, the skier, while attempting to secure the binding, presets the pressure so high that release does not occur when the skier falls. In other Words, the safety factor of the safety binding is overridden by the skier who wishes to avoid release during strenuous ski maneuvers.

The mechanical safety bindings presently in use by skiers throughout the world are made up of exposed spring loaded linkages, ball and socket joints and other well known mechanical release structures. Oftentimes, changes in temperature, humidity or other atmospheric conditions result in expansion or contraction of the mechanical elements which provide the release. Skiers typically set the pressure at which they wish bindings to release early in the season and give the setting no further attention. As the season progresses and as temperature, humidity and atmospheric conditions change, theskier does not readjust the pressure setting. Consequently, a fall in midwinter may not cause the binding to release while a fall in the late Fall or early Spring may cause the binding to release.

Further, the exposed mechanical linkages and spring 'ice loaded mechanisms often become clogged with snow, preventing effective release when a situation demands release of the binding.

With these comments in mind it is to the elimination of these and other disadvantages to which the safety ski.

binding of this invention is directed along with the inclusion therein of other novel and desirable features.

An object of our invention is to provide a new and improved safety ski binding of simple and inexpensive construction and operation.

Another object of our invention is to provide a ski. binding which does not rely upon complex mechanical apparatus to release, but which will release when the binding assumes a predetermined position of rotation about the longitudinal axis of the skier or about the transverse axis of the ski, yet maintains positive connection with the ski boot until such predetermined position is reached and is not affected by temperature, humidity or other atmospheric changes.

Still another object of our invention is to provide a ski binding which does not rely upon complex mechanical apparatus to release but which will release when the binding is placed under a predetermined pressure, yet maintains positive connection to the ski boot until such predetermined pressure is reached and is not affected by temperature, humidity or other atmospheric changes.

A further object of our invention is the provision of a safety ski binding which will release at a predetermined pressure of the boot on the ski binding and will also release in response to a predetermined position of the ski.

These and other objects and advantages of our invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views, and in which:

FIG. 1 is a side elevation view showing our safety binding mounted on a ski and securing a boot within the binding.

FIG. 2 is an isometric view showing the detail of the assembly of our safety binding.

FIG. 3 is a section view of a portion of the boot securing mechanism, the section taken along the line 3-3 of FIG. 1.

FIG. 4 is a section view of the mercury switch which actuates the solenoid, the section taken along the line 44 of FIG. 2.

FIG. 5 is an isometric view showing a modified form of the assembly of our invention.

FIG. 6 is a modified mercury switch which operates the solenoid in the modified assembly.

FIG. 7 is a section view showing the contact wire arrangement of the modified mercury switch, the section FIG. 12 is a schematic diagram of the electrical circuit of the alternate form of our binding.

FIG. 13 is a schematic diagram of the electrical circuit which utilizes both position and pressure sensitive switches. FIG. 1 shows a boot 10 secured in the safety binding indicated in general, by numeral 11.-Safety binding 11 is affixed to ski 12. A toe plate 13 and a heel plate 14 typically formed from steel plate stock, are secured on boot 10. Toe plate 13 includes a recess 15 which cooperates with,

in general, safety binding 11 to releasably secure boot to ski 12. Heel plate 14 includes a ball shaped protuberance 16 which seats in socket 17 in heel mount bracket 18 which is secured to ski 12, by screws 19. In the secure position, safety binding 11 engages toe plate 13 at toe recess and ball 16 is seated in socket 17, thus preventing movement of boot 10 relative to the ski. A manual binding securing button 20 is shown in FIG. 1 on safety binding 11. Also shown is circuit actuating switch 21.

The toe plate 13 of boot 10 is secured to ski 12 by the action of boot engaging member 22 which is spring loaded, the spring indicated by numeral 23 in FIG. 2. The boot engaging member is typically a steel rod having a conical point. FIG. 2 shows boot engaging member 22 in release position, and spring 23 in relaxed position. A collar 24 is aifixed to member 22 securing spring 23 at a predetermined setting along member 22. Boot engaging member 22 projects through mounting wall 25 and co-acts with recess 15 in toe plate 13 when the spring is in tension. Recess 15 typically has a mating conical recess to facilitate retraction of the rod from the recess even without the aid of spring 23 but simply under pressure of boot movement. Member 22 extends through support 26 and is slidable therein, to hingedly connect the floating toggle link 27. Link 27 is hingedly connected at one end thereof to rod 22, and at the other end thereof is hingedly connected to mating toggle 28. Toggle 28 in turn is pivotally mounted to fixed post 29, which is secured to ski 12 by nut 36. The hinged connection of toggle 27 to mating toggle 28 will not pass through dead center since a stop 31, having a predetermined setting, prevents this. The toggle links may be formed from a rigid material such as steel or aluminum.

As shown in FIG. 2, the ski binding is in release pos tion. In the release position, boot engaging rod 22 does not extend past wall 25, and toggles 27 and 28 are at oblique angles with each other. As toggles 27 and 28 approach a straight line relation, rod 22 projects outwardly from wall 25 and engages recess 15 and toe plate 13. The mechanism for retaining toggles 27 and 28 in an approximate straight line relation is shoWn in FIG. 2, indicated in general by numeral 32.

Referring now to FIG. 3, the mechanism 32 for retaining toggles 27 and 28 in an approximate straight line relation is shown in detail. A partial cross-section of the binding cover 33 is shown having a binding securing rod 34 extending therethrough. Binding scouring rod 34 shows the manual binding securing button 20 above cover 33 at one end of rod 34, and, at the other end of rod 34, a transverse circular plate 35 affixed thereto. Plate 35 mates with pressure plate 36 which, in the secure position, retains the substantially straight line relation of the toggle links and said boot engaging member.

Plunger 37 extends downwardly from pressure plate 36 into bore 38 in block 39. Plunger 37 includes a locking groove 40 adapted to receive a cooperating locking ball 41 actuated by an elongate rod 42 disposed in bore 43 in block 39, bores 38 and 43 being in substantially right angular relation. In secure position, pressure plate 36 retains toggle 27 in substantially straight line relation with boot engaging member 22, and ball 41 seats in locking groove 40 in plunger 37. Solenoid operated lever arm 44 remains actuated in the secure position and retains lever arm 44 in contact with elongate rod 42, thereby securing ball 41 in groove 40.

As shown in FIG. 2, lever arm 44 is pivoted about upright pivot point 45 for movement against elongate rod 42 or away from rod 42. A solenoid 46 is energized by batteries 47 connected in series to solenoid 46. The solenoid 46 is energized in the secure position and retains solenoid plunger 48 in solenoid 46. Solenoid plunger 48 is pivotally connected to lever arm 44 which pivots about pivot 45. In the release position, solenoid 46 is no longer energized, thereby releasing solenoid plunger 48 and allowing lever arm 44 to pivot about point 45 which releases ball 41 from groove 40.

A mercury switch, indicated in general by numeral 49, is interposed in series with solenoid 46.

Mercury switch 49, referring to FIG. 4, is actuated when the ski and attached boot rotate about a longitudinal or transverse axis to a predetermined setting of the switch which setting corresponds to a position of the boot relative to the ground. Switch 49 is mounted on ski 12 and includes a mercury pool 50 placed in a conical cavity 51. The mercury 50 is acted upon by gravity and consequently maintains a horizontal attitude. A pair of contacts 52 are disposed in an upright position, through pool 50, and into cavity 51. As the ski 12 assumes a position past the preset position, mercury 50 no longer contacts both elements 52, thereby breaking the circuit and deenergizing solenoid 46. The sensitivity of mercury switch 49 may be adjusted by manipulating knob 53 which raises or lowers washer 54. As washer 54 is lowered downwardly into conical cavity 51, the distance, indicated in general by letter (x), decreases and therefore mercury 50 is released to its normal horizontal state at a slower rate. As dimension (x) increases, of course, mercury 50 regains its horizontal level more quickly. Washer 54 is circular and constructed of a dielectric material. Contacts 52 retain internally threaded washer 54 from rotating, and it moves upwardly or downwardly along screw 55 which is actuated by knob 53. A plastic housing 56 surrounds cavity 51 and encloses elements 52. Leads 57, extending from elements 52, connect switch 49 in series with the solenoid 46 and energizing means 47.

A modified form of our invention energizes the solenoid when a modified mercury switch reaches a predetermined position. In this embodiment, circuit energizing means are conserved in that contact is only made at the time of a skiers fall rather than energizing the solenoid until the skier falls. FIG. 5 illustrates the mechanical changes necessary to arrive at the alternate embodiment of our invention. Solenoid operated lever arm 58 pivots about upright pivot 59, contacting elongate rod 60 which actuates a ball into locking groove 61 on plunger 62. Fig 5 shows the mechanism in release position, however, when pressure plate 63 is depressed against toggle 64, boot engaging member 65 is placed in secure position. Spring 66 pushing against lever arm 58 which pivots about pivot 59 contacting elongate rod 60 maintains pressure on locking groove 61 maintaining boot engaging element 65 in the secure position. Since spring 66 is applying pressure on lever arm 58, the circuit energizing means 67 is not being used. When the skier falls the ski must rotate about a longitudinal or transverse axis, actuating mercury switch 68 which is interposed in series with energizing means 67 and solenoid 69. Mercury switch 68 operates to energize solenoid 69 and draws plunger 70 into the transverse bore within solenoid 69. This places spring 66 in compression and pivots solenoid operated arm 58 about pivot 59, releasing the pressure exerted against elongate rod 60 and subsequently against locking groove 61. This releases boot engaging member 65 and frees the skier.

The detail of switch 68 is shown in FIG. 6, and includes a circular plastic housing 70 which has a conical cavity 71 therein. Mercury 72 is placed in this cavity. A dielectric washer 73 is afiixed to an upright threaded member 74 which is threaded into internally threaded aperture 75 and attached to knob 76. Knob 76 controls the height of Washer 73 and determines the dimension (y) between the wall of cavity 71 and the edge of washer 73. As the dimension (y) increases, mercury 72 more freely flows into the upper portion of cavity 71 and contacts wires 77. As shown in FIG. 7, contacts 77 are concentric and operate to dispose the mercury switch 68 in series with energizing means 67 and solenoid 69. As sufiicient mercury flows from pool 72, contact is made with concentric rings 77, thereby closing the circuit and actuating the solenoid 69.

The electrical circuitry of our invention is shown in FIG. 8 and includes a circuit 78 having circuit energizing means 79 and a solenoid 80 disposed in series. Circuit actuating switch 81 is included in the circuit as well as mercury switch 82. In the first mentioned embodiment of our invention, mercury switch 82 is normally closed. In the modified embodiment of our invention, mercury switch 82 is normally open. Switch 81, of course, must be in the closed position to make the safety binding operative. This switch 81 is actuated by the skier in assembling the binding to the boot.

Referring to FIG. 9, an alternate embodiment of our improved safety ski binding is shown, and is indicated, in general, by numeral 83. This embodiment of the safety ski binding is pressure sensitive and releases at a preset pressure of the boot against the binding. The boot moves relative to the ground to affect release thereof. The pressure sensitive assembly may be used singly or in conjunction with the position sensitive embodiment. A portion of the boot is shown in position on binding 83 and is indicated at 84. The ski 85 receives binding 83 and is secured thereto by conventional mounting means. The linkage apparatus which is actuated by the pressure sensitive mechanism is similar to the linkage apparatus shown in FIG. 2. The ski binding is shown in the release position in FIG. 9. A boot engaging rod 86 is surrounded by spring 87 which is in the relaxed position. A collar (not shown) is secured to the rod 86 maintaining spring 87 in position on rod 86 between the upright supporting block 88, through which rod 86 is slidably mounted, and the block 91. The collar causes the spring to be in compression when the rod engages the boot. Upright support 88 is aflixed to a plate 89 which is pivotally mounted to the ski 85 at pivot 90, for rotation in a plane parallel with the ski. Further, pivot point 90 acts as a fulcrum for movement of plate 89 in a plane generally normal to ski 85 when upward pressure is exerted on by the boot on the rod 86. Plate 89 is typically constructed of a tempered steel strap of suitable thickness allowing bending of the member. Block 91 is secured to plate 89 and includes a bore 92 therein adapted to slidably receive rod 86. A recess 93 is provided at bore 92 to receive a portion of spring 87 when under compression. A positioning and receiving member 94 receives block 91 therein positioning it in predetermined position relative to ski 85. Limit switch 95 is aflixed to receiving and positioning member 94. Switch 95 is a commercially available limit switch and is connected to solenoid 96 through conventional electric circuitry, shown in part at 96b in the same manner that the gravity sensitive switch 49 is connected to the solenoid 46 in FIG. 2. Solenoid 96 is energized by batteries 97 which are connected to the limit switch and solenoid circuit through conventional electric circuitry. Cam follower 98 is mounted on receiving and positioning member 94 and is adapted to follow cam 99 which is mounted on block 91. Follower 98 activates limit switch 95 in response to movement of cam 99. Therefore, block 91 is operably connected with limit switch 95 whereby movement of block 91 de-energizes solenoid 96 releasing rod 86 from the ski boot. The release mechanism which is operated by the solenoid 96 is the same as the release mechanism described hereinabove with reference to FIG. 2 and FIG. 3.

Referring to FIG. 10, limit switch 95 is shown on re ceiving and positioning member 94. Cam 98 is shown mounted on member 94 at block 100 which is secured to member 94 with bolt 101 and which receives bolts 102 securing follower 98 in such a way that it may follow cam 99. Cam 99 is essentially a ball imbedded in block 91 and protruding therefrom. An aperture 103 is included in follower 98 and is adapted to mate with ball or cam 99. As shown in the dotted lines, movement of block 91 causes cam or ball 99 to move within aperture 103 causing follower 98 to move upwardly thereby engaging limit switch button 104 and forcing the button upwardly activating limit switch 95. In the normally closed circuit, described hereinabove with reference to FIG. 2, the solenoid 96 is de-energized thereby releasing boot 84 from the binding. Block 91 is shiftably movable longitudinally, transversely, or in combinations of these movements in response to pressure on the binding exerted by boot 84. Block 91 is mounted on plate 89 which is pivotally mounted on the ski at pivot thereby allowing movement of the block in the transverse direction pivoting at pivot 90 or upwardly with pivot 90' acting as the fulcrum point. In this embodiment, downward movement of block 91 is not permitted although pivot point 90 may be elevated to provide downward movement and subsequent release of the boot if necessary. Recess 93 receives the spring which encircles rod 86. Positioning elements 105 are shown positioning block 91 in a predetemined position within member 94.

Referring to FIG. 11, a cross-section of the receiving and positioning member 94 shows the spring loaded positioning elements 105 positioning block 91 in member 94 for transverse and longitudinal movement therein. Rod 86 which engages ski boot 84, is shown slidably mounted within block 91 and the pivot plate 89 is shown. Springs 106 are disposed in member 94 in cylindrically shaped apertures 187 which are internally threaded to receive set screws 108. Set screws 108 may be adjusted to compress or de-compress springs 106 thereby increasing or decreasing the amount of force which the boot 84 must exert to pivot or raise block 91. Member 94 is typically constructed from an impact resistant plastic with apertures 107 turned therein to provide the internally threaded walls. Positioning pins 105 may be constructed from rigid plastic or an alloy steel. Block 91 is constructed from metal or plastic. Springs 106 are commercially available and may be obtained in various turns per unit length to achieve optimum operating characteristics.

Referring to FIG. 12, the schematic diagram of the electric circuitry of the alternate embodiment of our invention is shown. A normally closed arrangement is shown which provides an energized solenoid during operation with the limit switch breaking the circuit and de-energizing the solenoid thereby releasing the boot. Of course, the solenoid may be in a normally open position similar to the linkage shown in FIG. 5, with the solenoid plunger held in position by a spring, releasing the boot in response to completion of the circuit. A power source is indicated at 109and is connected in series to a solenoid 110. The pressure sensitive solenoid actuating assembly described in FIGS. 10* and 11 is indicated at 111 and is shown as normally closed. An on-off switch is indicated at 112 and is indicated as open in which position the binding is at rest and is not securing a boot within the binding.

FIG. 13 is the circuit diagram which shows the gravity sensitive switch and the pressure sensitive switch in combination. A power source is indicated at 113 connected in series to solenoid 114. On-off switch 115 is indicated as open, since the binding is shown at rest and not engaging a boot. Position sensitive switch 116 is shown in the normally closed position in which the solenoid is energized until a position of the ski causes switch 116 to open thereby de-energizing solenoid 114. The pressure sensitive switch 116 is connected in series in the circuit and is shown as normally closed. In the normally closed arrangement, a predetermined pressure of the boot in the pressure switch causes switch 117 to open the circuit thereby deenergizing solenoid 114 and releasing the boot. Of course, the switches may be normally open with the boot release apparatus modified as described in FIG. 5 hereinabove.

It will therefore be seen that we have provided an improved safety ski binding which releases in response to a position of the ski, which releases in response to a pres sure of the boot on the binding, or which releases in response to a combination of position and pressure. In each 7 instance the boot moves relative to the ground to affect release thereof. Further, we have provided a ski binding which positively joins the binding and the boot until the precise predetermined condition is met at which time release is instantaneous. A normally closed circuit, in which batteries supply energy to the solenoid when the binding is in use releases in response to a break in the circuit. A normally open circuit may also be used which releases in response to completion of the circuit. The mechanical linkage which joins the solenoid to the boot engaging rod is varied in the normally open circuit. The variation is shown in FIG. 5. In the normally open circuit, energy is drawn from the batteries only at such time as the pressure of the boot or position of the ski calls for release of the boot from the binding.

The positive engagement of our binding affords the skier maximum control of the skis at all times, even during intricate turning maneuvers. Further, adjustment may be made in both the position sensitive and pressure sensitive switches to provide optimum operating characteristics for skiers from the beginning to expert classes. It will also be seen that we have provided a binding which is not appreciably affected by changes in temperatures, humidity or other atmospheric conditions and which substantially maintains the preset operating characteristics throughout the skiing season without the need for further adjustment. This is particularly important in providing a safe ski binding in that the typical skier does not bother to adjust his bindings throughout the season and often-times receives injuries which would otherwise be avoided if the bindings were properly adjusted.

It will, of course, be understood that various changes may be made in form, details, arrangement and proportions of the various parts without departing from the scope of my invention.

What is claimed is:

1. A safety binding adapted to be aifixed to a ski to permit secure binding of a ski boot to a ski, said binding comprising a boot engaging member adapted to be aflixed to a ski for shiftable movement thereon, said boot engaging member having a release position and a secure position,

an electrically actuated release mechanism co-operable with said boot engaging member, said release mechanism adapted to shiftably move said boot engaging member from the secure position to the release position,

circuit means connected to said electrically actuated release mechanism,

means energizing said circuit means and switch means predetermined affixed to and supported from said ski interposed in said circuit means to actuate said release mechanism to shiftably move said boot engaging member from the secure position to the release position in response to predetermined tilting of the ski on either transverse or longitudinal axes with the attendant pressure effect of the ski boot on the binding.

2. The safety binding of claim 1 in which said electrically actuated release mechanism comprises a solenoid mechanically linked to said boot engaging member for shiftably moving said boot engaging member from the secure position to the release position.

3. The safety binding of claim 1 wherein said switch means actuates said release mechanism to shiftably move said boot engaging member from the secure position to the release position in response to predetermined tilting of said ski on transverse and longitudinal axes.

4. The safety binding of claim 1 wherein said switch means predeterminably mounted and supported on said ski comprises a gravity responsive switch, said gravity responsive switch comprising a housing having a conical cavity therein, the conical cavity containing mercury, contact elements disposed in the mercury connecting said switch in said circuit, means whereby the mercury maintains a substantially horizontal level as the switch rotates about a longitudinal or transverse axis thereby causing the mercury to assume a position to actuate said release mechanism to shiftably move said boot engaging member from the secure position to the release position.

5. A safety binding adapted to be affixed to a ski to permit secure binding of a ski boot to a ski, said binding comprising a boot engaging member adapted to be afiixed to a ski for shiftable movement thereon, said boot engaging member having a release positition and a secure position,

an electrically actuated release mechanism cooperable with said boot engaging member, said release mechanism adapted to shiftably move said boot engaging member from the secure position to the release position,

circuit means connected to said electrically actuated release mechanism,

means energizing said circuit means and switch means interposed in said circuit means to ac tuate said release mechanism to shiftably move said boot engaging member from the secure position to the release position in response to movement of the ski boot relative to the ground,

wherein said switch means interposed in said circuit means actuates said release mechanism to shiftably move the boot engaging member from the secure position to the release position in response to a predetermined pressure of the ski boot in said binding.

6. The safety binding of claim 5 wherein said switch means comprises a housing,

a positioning block mounted in said housing for shiftable movement therein, said positioning block operably connected to said boot engaging member and responsive to the shiftable movement thereof,

bias means positioning said positioning block in a predetermined position relative to the ski boot and a limit switch opera-bly connected to said positioning block whereby movement of the ski boot relative to said positioning block actuates said limit switch to control said release mechanism shiftably moving said boot engaging member from the secure position to the release position.

7. The safety binding of claim 5 wherein said bias means comprises a plurality of adjustable springs secured in said housing and projecting into contact with said positioning block urging said positioning block in line with said shiftably mounted boot engaging member.

8. The safety binding of claim 5 wherein said electrically actuated release mechanism comprises a solenoid operated assembly for controlling said boot engaging member, said assembly including,

a toggle mechanism interposed between said boot engaging member and a solenoid,

a toggle mechanism pressure plate adapted to actuate the toggle mechanism from release position to secure position,

a plunger receiving block adapted to be afiixed to the ski,

a plunger attached to the pressure plate and having a locking groove in the periphery thereof, said plunger slidably mounted in said block a ball co-opera'ble with the plunger locking groove and a ball actuating element disposed slidably in the block whereby, in secure position the ball and ball actuating element hold the toggle mechanism pressure plate in contact with the toggle assembly,

a solenoid control mechanism responsive to said switch means, said control mechanism co-operable with the ball and ball actuating plunger to permit control of said boot engaging member, said control mechanism including 9 10 a solenoid, References Cited a lever arm pivotally mounted on the ski, the lever UNITED STATES PATENTS arm having a binding secure position cooperable with the ball actuating plunger to retain the ball in the 2698757 1/1955 Berlenbach 280-1135 plunger locking groove and a binding release posi- 3,246,907 4/1966 Chlsholm tion in spaced relation to the ball actuating plunger, 312511607 5/1966 Wren 28o11-35 said lever operably connected to said solenoid whereby said solenoid actuates said lever arm, con- BENJAMIN HERSH Pnmary Exammer' trolling said boot engaging member in response to MILTON L. SMITH, Examiner. movement of the ski boot relative to the ground. 10

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