System for changing the stiffness of a ski

Abstract: A system for changing the stiffness of a ski includes springs for urging a ski boot into a ski binding, and apparatus for modifying the biasing force to change the stiffness of the ski.

Description: This invention relates to a system according to the preamble of claim 1, and is intended for varying the characteristics of a ski according to the nature of the snow being skied upon, the type of skiing being performed, the nature of the ski and the skill of the skier, to improve the quality of the skiing and safety of the skier. It relates in particular to apparatus which vary the stiffness of the ski according to the foregoing conditions. Description of Background and Relevant Information Important conditions affecting downhill skiers are the nature of the snow, the type of skiing to be done, the type of skis and bindings used and the skill of the skier. The snow and the ski run can vary during a day, while the ski and the skier are generally invariable. The snow can range from ice hard snow, to very loose or soft snow, sometimes called powder snow. There are profound differences in skiing turns and speed according to the type of snow being skied upon. One primary characteristic of a ski is its ability to bend or flex longitudinally, with its forward and rearward portions moving above the center part of the ski, as it carries a skier. A ski flexes and counterflexes, and keeps the skier in control as he or she follows the contour of a slope and enables a skier to manipulate the skis as he or she bounds and rebounds down the slope. In racing events, the snow can be ice hard both to increase the skier's speed and to avoid ruts in the snow. Hard snow may limit the bending of the skis. Turning is mainly accomplished in hard snow by the skier tilting the skis to dig the edges at the bottom of the ski into the snow by shifting his or her weight and body position. On the other hand, the ski can bend in a large amount in powder snow. The longitudinal sides of skis are convex arcs, and it is through the use of the side cuts and bending of the ski that the skier turns; the edges of the skis are of much less importance in turning in powder snow. Regular snow, that is snow whose texture and packing is between hard snow and powder snow, presents other problems to the skier. Experience, communications with racers and other skiing experts, and testing, indicate that a ski stiffer underfoot of the ski boot may be preferable in very hard snow conditions while an overall more flexible ski appears to be preferable in soft snow conditions. An intermediate situation is preferable for snow of intermediate softness. It is also known that a ski loosely attached to the skier transfers little energy from the ski to the skier when the ski encounters obstacles, thus resulting in higher speed. However, a loose attachment results in loss of ski control in turns; hence it is desirable to have a loosely connected ski when traveling essentially in a straight line for greater speed and a tightly connected ski when making turns for greater control. The vibration characteristics of skis are also believed to be important. Skis have several vibration modes which are exhibited during skiing. High frequency vibrations break the contact between the ski bearing surface and the snow, which improves speed. On very hard snow conditions, the breaking of the contact between running surface and snow does not result in the same level of benefit but the ski still vibrates resulting in audible and perceptible chatter. A reduction in chatter is desirable in these conditions. Thus different requirements in underfoot stiffness and vibration exist depending on snow conditions. The ski designer, faced with the different kinds of snow, the different types of skiing, and variations in skiers and their bindings, can only develop skis which can handle all of these varying characteristics reasonably well but are not optimized for any specific condition. All ski bindings have an effect on ski stiffness underfoot. When a ski bends during skiing, the distance between the toe piece and the heel piece varies since they move relative to each other with the upward curvature of the ski. However, the length of the ski boot sole remains constant. Therefore, there is generally a limited movement rearwardly of the heel piece in a clamp on the ski to keep it in contact with the boot. The force required to move the heel unit back results in a stiffening of the ski section directly under the binding and boot. It is believed that most ski bindings on the market fall into this category. Therefore ski manufacturers take this stiffening action of the binding system into consideration in the design of the ski. The underfoot stiffness of the ski/binding combination is thus optimized for the type of skier and preferred snow conditions for which the ski was intended. Different binding systems and separate devices to be used in conjunction with the ski and commercially available bindings have been manufactured to either increase or decrease the underfoot stiffness of the basic binding/ski configuration. Other devices can effect the normal vibration of a ski. Combinations which decrease stiffness underfoot may improve soft snow skiability while deteriorating skiability towards the end of the hard snow spectrum. Combinations which increase stiffness have the opposite effect. In some systems, the binding is constructed to render the ski more flexible. In the ESS v.a.r. device, a boot support plate having a forward portion which is slidable in a channel on the ski, should render the ski more flexible. However, the support plate is fixed with additional fastening means to the ski, and thus is believed to limit its benefit on soft snow. The fixing of the support plate decreases the bending of the ski. The Tyrolia Freeflex system utilizes a flexible plate attached to the top of the ski. The plate is fixed to the ski at the toe of the binding and is held in place about the heel by a slidable clamp fixed on the ski. Both toe and heel binding units are affixed on the boot support plate. When the ski bends, the heel clamp moves closer to the toe unit but the flexible plate is allowed to slide rearwardly reducing the tendency of the heel unit to move towards the toe unit as in a normal binding configuration. The ski is thus allowed to flex more underfoot. The plate is allowed to move in the slidable clamp but is also held to the ski by an additional sliding point between the toe and the heel. This mounting configuration increases sliding friction and thus the overall decrease of ski stiffening is relatively small. Devices of this nature are disclosed in U.S. Patent 3,937,481. Most ski binding manufacturers produce bindings which increase the stiffness of skis. The stiffness of a ski provides a firm edge to drive into the snow for making turns in hard or intermediate snow. In this respect, it is much like an ice skater who drives his or her blade into the ice to make a turn. A flexible blade would detract from the skater making a turn, just as a very soft ski in the section directly below the boot would detract from the skier turning in hard snow. Some expert skiers performing giant slalom or super giant slalom have found that their turning ability is enhanced when they attach to the ski, such as by gluing, a thin plate on top of the ski in the binding area. This added plate increases the distance between the skier's boot and the edges of the ski, and enhances the leverage which the skier has to drive the edges of the ski into the snow. WIPO Document 83/00039 discloses a device wherein glue and an elastomeric material hold a plate for supporting a toe piece and heel piece to the ski. The elastomeric material absorbs some of the vibration of the ski on the hard snow and relieves some of the discomforting noise of the ski rapidly smacking against the snow. Furthermore, the device stiffens the ski/plate/binding combination in the underfoot area of the ski improving edge control on hard snow. In another device called the Rossi-Bar and disclosed in European Patent Office Publication No. 0409749, a support bar on the ski has stops of elastomeric material at its forward and rearward ends. However, the bar is locked to the ski by clamps along the length of the bar, and it is the clamps and not the rubber stops which prevent the bar from sliding on the ski. Thus, the plate reduces the bending of the ski. In U.S. Patent 3,937,481 (mentioned earlier) a ski binding having an elongated plate is slidably mounted thereon for cushioning the skier when a forward abutment is encountered. Only the forward or toe portion of the system is fixed to the ski, so that the plate allegedly follows the bending of the ski. The device in fact impedes the bending of the ski since it is strapped to the ski in a number of places. A similar device with similar shortcomings is disclosed in Austrian Patent 373,786. A device of this type is sold under the name Derbyflex. It has been believed by many experts that raising the ski binding with such a plate detracts from the skier's ability to control the ski, since it was thought that the skier had to be close to the snow to "feel" the snow and ski accordingly. The present inventors and other manufacturers believe that this notion is wrong for most types of skiers, and that holding a ski boot somewhat high over the ski increases his or her ability to control the ski. Other patents disclosing ski bindings for increasing stiffness in skis include German Patent 2,135,450 and European Publication 0409749A1. Even though the added plate is beneficial, it only applies to skiing on hard snow where a stiffer underfoot ski is desirable. When used on softer or powder snow, the added stiffness detracts from the skier's ability to control the ski since easier bending adds to the turnability of the ski in soft snow. Other devices are known having movable boot support plates on skis. For example, U.S. Patent 4,974,867 discloses a shock absorbing buffer disposed between a ski and a binding, and is not really related to the stiffness of the binding. The skill of the skier is another condition which the skiing apparatus should take into consideration. Although stiff skis are beneficial to good skiers in events such as giant slalom and super giant slalom, novice skiers should generally use flexible skis for all events, since they enable reasonable performance even though edge control in turns may be sacrificed. The inventor is unaware of any ski bindings or skis which are adaptable to vary the stiffness in the binding location of a ski system according to the nature of the snow or the type of skiing being done. He is aware of no skiing system whose stiffness and vibration characteristics can be changed to perform well in the various skiing conditions. Brief Description of the Invention It is an object of the invention to provide an improved device for controlling snow skis according to the nature of the snow, the skiing to be done, the type of skis and/or the skill of the skier. This object is solved by the features of the characterizing part in claim 1. The invention comprises systems for controlling the stiffness of a ski to the longitudinal bending of the ski. The systems include a series of members which are movable relative to each other and fixed to the ski at the opposite ends of the series. Biasing means operatively connect these members. The force of the biasing means on the members can be changed to change the stiffness of the series of members and of the ski beneath the series. In one embodiment, the system includes a heel piece having a forward pressure spring for urging a ski boot forwardly towards the toe piece fixed on the ski, and other biasing means which can selectively apply their bearing force on the boot to vary the stiffness between the heel piece and the toe piece, and on the underlying ski. Many varieties of biasing means, such as coil springs. leaf springs, resilient material, hydraulic means and the like, can be used. The ways of activating the biasing means are also wide in number, and could include movable abutting surfaces, linear or rotating spring activating and deactivating means, and the like. In another embodiment, the boot sole has separate portions which are longitudinally movable when received in a ski binding, and biasing means operatively connecting the portions for urging the sole into the ski binding which now can have fixed toe and heel pieces. The biasing means controls the stiffness of the boot sole and of the ski, and the biasing force can be varied to change the stiffness. The biasing means can include two or more springs which can selectively be activated to exert their biasing force and increase the stiffness, or be deactivated to reduce the stiffness. In still another embodiment, biasing means are applied at the toe or the heel of the boot for holding the ski boot between the toe and heel pieces. These biasing means contribute to the stiffening of the ski, and can be varied by varying the biasing force. Other objects will occur to those skilled in the art and to which the appended claims pertain. Brief Description of the Drawings The invention will be better understood when reference is had to the following drawings in which like numbers refer to like parts, and in which: FIG. 1 is a schematic drawing of a side of a heel piece according to the prior art, showing ski boot mounted in a ski binding, with the ski binding being shown schematically where parts of the heel piece are omitted to indicate the inside of the binding. FIG. 2 is a side schematic view of a heel piece of a ski binding as shown in FIG. 1, showing the forward pressure spring and the screw assembly for locating that spring in the heel piece. FIG. 3 is a top view of the heel piece shown in FIG. 2, with part of the heel piece omitted to more clearly show the internal parts of the ski binding. FIG. 4 is a plan view of an embodiment of the invention, showing a ski boot sole with portions removed to indicate important parts of the invention. FIG. 5 is another embodiment of the invention showing a sole having more than one portion with another means for operating the invention. FIG. 6 is a view taken in the direction 32-32 in FIG. 5. FIGS. 7 and 8 are plan, cut away views of ski boot soles according to other embodiments of the invention. FIG. 9 is a side view of yet another embodiment of the invention, showing spring means at the toe piece of a boot which is mounted on a ski. FIG. 10 is another schematic view of another embodiment of the invention, shown in side, partially cut-away form. Detailed Description of the Preferred Embodiment of the Invention FIGS. 1, 2 and 3 show a typical ski binding for attaching a ski boot 1000 with a sole 1005 to a ski 107. The binding includes a toe piece 1001 which is fixed to ski 107 and a heel piece 1003 which is mounted on the ski. The boot has a sole 1005, and is attached to the ski by having its toe portion 1007 engaged by toe piece 1001 and its heel portion 1009 engaged by heel piece 1003. The toe piece 1001 is fixed or stationary on the ski. Heel piece 1003 includes a track 1001 which is fixed to the ski. Track 1011 includes a housing guide 1013 for guiding a housing 1015 (discussed below) for adjustment to different sizes of ski boots, and a screw guide 1017 for the adjustment screw. Housing 1015 carries a heel holder 1019 which is pivotal about a laterally extending axis 1021, to move between a raised position for receiving a heel of a ski boot and a lowered position (Fig. 2) for holding the boot heel on the ski. The forward position of heel holder 1019, which engages the heel, is closer to the toe piece when it is in the lowered position rather than it is in its raised position. A handle 1023 is operatively attached to heel holder 1019 for manually opening the heel holder, by pivoting the heel holder 1019 about axis 1021 and releasing the release spring (not shown). Housing 1015 further carries a forward pressure spring 1025 which is compressed when a boot is being held and urges the heel holder 1019 forward, to urge the boot sole 1005 into toe piece 1001. The housing 1015 can be moved forward or backward in track 1011 by the adjustment of a screw assembly 1027 which urges a spring abutting plate 1029 forward. Screw assembly 1027 is fixed at any of its settings to the ski. An aperture 1031 into which a head 1033 of screw 1035 of screw assembly 1027 can slide is provided, since housing 1015 is movable backward over the screw assembly as a boot is locked into the ski, and is also movable longitudinally relative to the screw assembly 1027 as the ski bends. As the ski is flexed or bent with the forward and rearward end sections of the ski bent upward, a boot sole mounted in a binding stiffens the ski against bending, and so does the forward pressure spring 1025 because it exerts a biasing force on the sole towards the toe piece. Using different forward pressure springs changes the stiffness of the binding, and adjustment of screw 1035 beyond its normal setting also changes the stiffness when the boot is mounted in the binding on the ski. The inventor has found that by adding a variable biasing means to the sole holder, the stiffness of the ski can be varied to obtain benefits of different stiffness of the ski for different skiing conditions. Referring now to the cut-away top view of a binding in FIG. 4, a binding 1101 similar to that of FIGS. 1-3 in some respects is shown. (Parts of binding 1101 which are the same as or similar to those in FIGS. 1, 2 and 3 are given the same numerical designation with a prime (') suffix.) Binding 1101 includes a track 1011' fixable to a ski, in which housing 1015', movable in a longitudinal direction, is located. A forward pressure spring 1025' abuts at its rear end to an abutment plate 1029', which is part of screw assembly 1027', and engages housing 1015' at its forward end for urging housing 1015' forwardly when the heel holder is in its down, heel-holding position. This urges the heel holder and boot sole 1005 forwardly against the toe piece. Spring means, here including longitudinally extending springs 1035 and 1037, are provided for abutment at their rear portions to abutment plate 1029'. Stiffener springs 1035 and 1037 are shown parallel to forward pressure spring 1025', and have forward portions 1039 and 1041. A pair of plugs 1043 and 1045 are shown in front of forward portions 1039 and 1041 of springs 1035 and 1037, for exerting the biasing force of those springs against housing 1015' when binding 1101 is in its boot-holding condition. The biasing force of each of these springs collectively adds to the biasing force of forward pressure spring 1025'. This adds stiffness to the sole and spring combination, and adds stiffness to the ski beneath the combination. A pair of spring actuating levers 1047 and 1049 are connected to a pair of plugs 1043 and 1045, and are rotatable about axes 1051 and 1053 perpendicular to ski 107, and extend outside of the area in which springs 1025', 1035 and 1037 are located. When plugs 1043 and 1045 are in the paths of springs 1037 and 1039, their faces 1055 and 1057 receive the biasing force of those springs and exert the biasing force on abutment 1059 of housing 1015'. In order to relieve the biasing of spring 1035 on sole 1005 and to decrease the stiffness of the ski, lever 1047 can be rotated counterclockwise as shown by the arrow 1055 to move the plug outside of the path of spring 1035, so that the forward end of spring 1035 is now not exerting its biasing force on housing 1015' or on sole 1005. Likewise, lever 1049 can be rotated clockwise to move plug 1045 out of the path of spring 1037 to deactivate that spring and eliminate its biasing force and the stiffness caused thereby. Movement of levers 1047 and 1049 should be done when the boot is not in the binding, since the spring is unloaded and easy to compress or decompress. The sole is configured to enable levers 1047 and 1049 to move their respective plugs. An appropriate stop is included to keep plugs 1043 and 1045 in the stiffening position in the paths of the two springs. Many variations on means for selectively applying biasing force to the sole to vary the stiffness of the ski are possible. If spring means are used to provide the biasing forces for adding and changing the stiffness of a ski, the spring means can include springs which are stacked horizontally or vertically; they can have different configurations; and they can be of various types such as leaf springs, wire springs and various resilient materials. They can be springs which exert their biasing force when compressed, or can be springs which are stretched to exert their force when the binding is placed in its boot-holding condition, and those springs can be changed or their force altered to change the stiffness of the ski. The biasing force could be hydraulic or electrical in nature for the various embodiments. One version of the invention involves the exertion of biasing forces on the ends of a ski boot sole to force the sole into a portion of a ski binding, and to vary the biasing forces to vary the stiffness of the ski to bending. Another version is to divide the sole itself into two sections, and to apply biasing forces between the sections to urge them into ski binding portions -- generally the heel piece and the toe -- and also has the effect of imparting stiffness to the ski as the ski bends. Biasing forces can be urged from the toe or the heel of the boot, and when inserted in a binding the biasing forces can urge the boot against the binding and add stiffness to the ski. In these situations, the heel piece and the toe piece can be fixed on the ski, since any movement of the sole relative to the ski as the ski bends is accomplished by the movement of the portions of the sole or by the entire sole. The biasing means can be varied to vary the stiffness of the ski binding. Referring to FIG. 5, a ski boot 1100 includes a ski boot sole 1103, which is divided into two portions -- a front portion 1105 and a rear portion 1107. These portions are operatively connected by spring means, which here is a spring 1109. Spring 1109 extends into channels 1111 and 1113, which themselves are aligned and extend longitudinally into sole portions 1105 and 1107 from the opposing edges 1115 and 1117 of the sole. Boot 1100 is shown for mounting in a binding having a toe piece fixed on a ski and a heel piece fixed on a ski. Boot portions 1105 and 1107 are relatively movable on boot 1100, and one possible means for doing this is discussed below. As sole 1103 is received between the binding parts, portions are urged apart from each other by spring 1109, which urges the forward and rearward ends of sole portions 1105 and 1107 against the toe piece and the heel piece. Spring 1109 also contributes to the stiffness of the sole and to the underfoot stiffness of the ski, and changes in the strength of spring 1109 likewise change this stiffness. FIGS. 5 and 6 depict one construction of boot sole 1103. In FIG. 6, the upper part of portion 1105 has a dovetail-shaped channel 1119 which is wider at its base than at its top. A flange or rib 1121 extending downwardly from the body 1123 of boot 1100 has a similar dovetail configuration, with its lower portion being wider than at its top, so that sole portion 1105 can slide on the flange. Sole portion 1107 is fixed to the ski boot, and portion 1105 is movable longitudinally. A protrusion 1125 extends upwardly in sole portion 1105 into a cavity 1127 in flange 1121. The cavity must be of such a length, defined by end walls 1129 and 1131, to allow movement of sole portion 1105 on flange 1121. In a preferred form of this embodiment, this length would be about 1 cm. An embodiment having a boot sole with more than one portion and variable biasing means is shown in FIG. 7. This version is similar to that shown in FIG. 4. The boot body and the means for attaching the movable portion or portions of the sole to the boot body are not shown, and only a top view of the sole is depicted. Here, a boot sole 1201 includes two portions 1203 and 1205 movable relative to each other, with forward portion 1203 being movable on the boot body, portion 1205 being fixed. Spring means, here three springs 1207, 1208 and 1209, extend longitudinally in aligned channels 1211 and 1213 in portions 1203 and 1205. Spring 1208 is a pressure spring for urging the sole portions into the binding portions when the boot is mounted on a ski. Plugs 1215 and 1217, rotatable by levers 1219 and 1221 on axes 1223 and 1225, move the plugs to selectively apply the biasing force of springs 1207 and 1209 to sole portions 1203 and 1205 to vary the stiffness of the sole and of the ski, as described earlier with respect to FIG. 30. Sole portion 1205 is configured to enable the movement of plugs 1215 and 1217. Sole portion 1203 can be movable by any convenient device, such as the flange and channel mechanism of FIGS. 5 and 6. Levers 1219 and 1221 should be operated when the boot is off the ski with springs 1207 and 1211 unloaded. FIG. 34 is another version 1301 of that shown in FIG. 7, and the same general parts have their earlier numerical designations with a prime (') sign. A ski boot sole 1201' has a forward or toe portion 1203' and a rearward or heel portion 1205', and springs 1207', 1208' and 1209', with spring 1208' being the primary forward pressure spring, extending between aligned channels 1211' and 1213' in the sole portions, with the forward ends of the springs abutting against the forward end wall of channel 1211'. A cam disc 1302 is rotatable about an axis 1303 extending vertically with respect to the sole, and a lever 1305 rotates the disc. The disc has an extended peripheral portion 1307 extending part way around the periphery of the disc, and a recessed portion 1309 extending the rest of the way. Those springs in compression by portion 1307 exert biasing forces on the sole portions, and increase the stiffness of the ski, since they resist the bending of the ski in the convex direction. Portion 1307 is always in the path of spring 1208', so that spring 1208' always exerts a forward pressure when the boot is mounted in the binding, since spring 1208' is the forward pressure spring. Those springs opposite recessed portion 1309 do not exert a compressive force on the sole portions and do not add to the stiffness of the ski when the boot is in a binding. When high stiffness of the ski is desired, such as when the ski slope is icy, the skier rotates lever 1305 clockwise when the ski is out of the binding and springs 1208' and 1209' are unloaded, to place extended portion 1307 in the paths of the springs, to compress the springs when the boot is placed in the binding. When less stiffening is desired, lever 1305 is rotated counterclockwise to disengage the disc from the spring, i.e., to place recessed portion 1309 in alignment with springs 1207' and 1209', so that the biasing force is not incurred on the sole portions. In another embodiment of the invention shown in FIG. 9, biasing means can exert biasing forces from the ski boot itself, and to make the system usable with a fixed toe piece 1401 and fixed heel piece 1403 on the ski. Biasing means, here spring 1407, extends from the toe part of the sole of the boot. The ski boot can be inserted with its biasing means 1407 engaging the toe piece to attach the boot to the ski. Means must be provided for holding the sole spring or biasing means in the toe piece. The biasing means exert stiffness to the ski to resist the bending of the ski and could be changed to change that stiffness. Another version of the invention is shown in FIG. 10, where a binding comprises toe piece 1001' and heel piece 1503 attached to ski 107. Heel piece 1503 includes a heel holder 1505 for engaging the sole at the heel of boot 1000, and a housing 1507 which is slidable in an appropriate track as the ski bends in the direction of arrow 1509. An attachment member 1511 is fixed to the ski, and has a set of springs 1513 attached at their forward ends to the rearward end of member 1511. The other ends of springs 1513 are attachable to housing 1507. Springs 1513 attached to housing 1507 are stretched when a boot 1000 is loaded in the binding. Springs 1513 contribute to the stiffness of the binding and to the underfoot part of the ski. Changing which of the springs exert biasing forces on the boot will change the stiffness of the ski; and means for changing the biasing force can include means for selectively hooking the rear ends of the respective springs 1513 to the downward leg 1508 of housing 1507, to stretch only those springs hooked thereto, to vary the stiffness of the ski. The movement of the biasing means described in FIGS. 4-10 to add stiffness to the ski is normally a small amount. In the embodiments shown it can be only a few millimeters to obtaining the stiffening action desired. Various systems for controlling the stiffness of a ski have been described above. The skier may manually, or perhaps with the ski pole or some other device, adjust the apparatus according to the type of stiffness to be desired. The skier need not have different skiing apparatus for different types of snow or different abilities of the skier, and need not settle for a binding which is appropriate for only one type of skiing or which approximate different types of skiing but cannot adequately control the stiffness precisely for different types of skiing. Now, the skier need only adjust the apparatus for the type of stiffness desired and to participate in the skiing event. The settings can be changed as the skier desires. Furthermore, in some embodiments the skier can continuously adjust the stiffness of the ski. Although many embodiments are given, it should be appreciated that other variations will fall within the scope of the invention as claimed.

Claims: A system for changing the stiffness of a ski (107), said system comprising holding means for holding a ski boot (1100) on a ski (107), said holding means having a first portion for holding a first part of the boot (1100) on the ski (107) and a second portion for holding a second part of the boot (1100) on the ski (107), said second portion being movable relative to the first portion as the ski bends characterized in that said system further comprises: at least two biasing means (1025', 1035, 1037, 1109; 1207, 1208, 1209; 1207', 1208', 1209') for exerting biasing forces for biasing the boot (1100) towards the holding means as the ski (107) bends; and changing means (1043, 1045, 1047, 1049; 1215, 1217, 1221; 1302, 1305) for changing the number of biasing means exerting biasing forces to change the stiffness of the ski (107) as the ski (107) bends. A system according to claim 1 characterized in that said first portion is the toe holder (1001') of a ski binding for holding to toe of a ski boot on the ski and said second portion is a heel piece for holding the heel of a ski boot on the ski, said heel piece including a heel holder for moving with the heel of the ski boot when the ski bends. A system according to claim 1 characterized in that said at least two biasing means comprise forward pressure spring means (1025'; 1208; 1207') and stiffening spring means (1035, 1037; 1207, 1209; 1208', 1209'), said spring means being compressible as the ski bends to increase the stiffness of the ski, and said changing means comprises movable spring abutment means (1043, 1045; 1215, 1217; 1302) movable between an active position wherein said abutment means operably engages at least one of said stiffening spring means to increase the compression of said stiffening spring means, and an inactive position wherein said abutment means is disengaged from said stiffening spring means. A system according to claim 1 characterized in that said biasing means comprises at least two springs (1025', 1035, 1037; 1109, 1207, 1208, 1209; 1207', 1208', 1209') extending longitudinally relative to a received ski boot and fixed at one end and free at the other end, and said changing means includes spring engagement members (1043, 1045; 1215, 1217; 1302), each member being associated with one of the springs and being selectively movable to an active position, to operatively engage the associated spring when the ski bends. A system according to claim 1 characterized in that said at least two biasing means comprises at least two spring means (1025', 1035, 1037; 1109, 1207, 1208, 1209; 1207', 1208', 1209') and said changing means includes a spring engagement member (1043, 1045; 1215, 1217; 1302) and movable lever means (1047, 1049; 1219, 1221; 1305) operatively connected to said spring engagement member for moving said spring engagement member between the active and inactive positions. A system according to claim 1 characterized in that said at least two biasing means comprises at least two spring means (1207', 1208', 1209') extending longitudinally relative to a received ski boot and each having a biasing force for selectively resisting movement of the ski boot as the ski bends, and said changing means comprises disc means (1302) rotatable about an axis (1303) transverse to the ski, said disc means having a periphery selectively engageable with at least one of said spring means for exerting the biasing force on the boot to increase the stiffness of the ski as the ski bends. A system according to claim 1 characterized in that said at least two biasing means comprises at least two spring means (1025', 1035, 1037), each fixable at one end to the ski and a second end selectively engageable with the second portion of said holding means, and said changing means is fixable to the second portion of said holding means. A system according to claim 1 characterized in that said second portion of said holding means comprises a heel holder for holding the heel of the ski boot on the ski, and said biasing means comprises forward pressure spring means (1025') and stiffening spring means (1035, 1037) located in the heel holder, said stiffening spring means having biasing force for selectively resisting the movement of the heel of the boot as the ski bends, and said changing means includes movable spring abutment means (1043, 1045) movable between an active position wherein said abutment means engages said stiffening spring means to increase the compression of said stiffening spring means when the ski bends, and an inactive position wherein said abutment means is disengaged from said spring means and does not increase the compression of said stiffening spring means when the ski bends. A system according to claim 1 characterized in that said second portion of said holding means comprises a heel holder for holding the heel of the ski boot on the ski, and said biasing means comprises forward pressure spring means (1025') and at least one spring (1035, 1037) extending longitudinally relative to a received ski boot and fixed at one end and free at the other end, and said changing means includes at least one spring engagement member (1043, 1045), each member associated with one of said at least one spring being selectively movable to the active positions, to operatively engage the associated spring when the ski bends. A system for changing the stiffness of a ski according to claim 1, the ski having a toe piece fixed on the ski, said system comprising a heel housing movable as the ski bends; a track on the ski for holding the heel housing in a sliding relationship; and a heel holder mounted on the heel housing for holding a ski boot, whereby said housing has a forward pressure spring (1025') for urging said heel housing forwardly to urge a boot held by the heel holder towards the toe piece, and at least one stiffening spring (1035, 1037) for selectively, operatively engaging said heel housing to urge the boot toward the toe piece, and said system further comprises means (1043, 1045, 1047, 1049) fixed to the housing for causing said stiffening spring to operatively engage said heel housing. A system according to claim 1, characterized in that said first portion is one portion (1107; 1205; 1205') of a ski boot, said at least two biasing means has a fixed portion fixed to the ski, and said changing means is fixed to said ski boot. A system according to claim 1 characterized in that sole means of the boot include first and second portions (1105, 1107; 1203, 1205; 1203', 1205') fixable in the binding, and biasing means (1109; 1207, 1208, 1209; 1207', 1208', 1209') operatively connected to said first and second portions having biasing force for biasing said first and second portions apart to add stiffness to the ski as the ski bends, said biasing means comprising a forward pressure spring (1208; 1207') for urging the ski boot into the ski binding when the boot is mounted on a ski and at least one stiffness spring (1207, 1209; 1208', 1209'), and further including spring engagement means (1215, 1217; 1302) movable between an active position for operatively engaging said stiffness spring to increase the stiffness of the ski, when the boot is mounted on the ski, and an inactive position for operatively disengaging said stiffness spring to decrease the stiffness of the ski. A system according to claim 12 characterized in that said boot sole is connected to a boot body (1123) and said system further includes stop means (1125) for preventing the separation of said first portion from said boot body. A system according to claim 11 characterized in that said first portion is attached to the toe end of the ski boot and the second portion is attached to the heel end of the ski boot, and said system further including attachment means (1121) for attaching said boot sole to the base of the ski boot for enabling a moving relationship between said first and second portions, and further including changing means (1215, 1217, 1219, 1221; 1302, 1305) for changing said biasing force to change the stiffness of the ski as the ski bends.

Inventors: RUFFINENGO PIERO G, RUFFINENGO, PIERO G.
Applicants: RUFFINENGO PIERO G, RUFFINENGO, PIERO G.
Application year: 1993
Main classification: A63C5
IPC codes: A63C5