The foregoing features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, the invention will be described with additional specificity and detail through use of the accompanying drawings in which:
It will be readily understood that the components of the present invention, as generally described and illustrated in the drawings herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the system and method of the present invention, as represented in the drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of various embodiments of the invention. The illustrated embodiments of the invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.
Referring to
The classic technique may include various sub-techniques such as the diagonal stride 10 and the double pole. These sub-techniques are suited to different terrain or snow conditions. For example, double poling may be considered a “high gear.” It utilizes primarily the upper body and includes a significant recovery stroke where no forward motion is being generated. Accordingly, double poling is well suited for fast snow conditions and terrain lacking any significant incline.
The diagonal stride 10 may be considered a “low gear.” It utilizes both the upper body 12 and the lower body 14. The lower body 14 provides an alternating “kick,” while the upper body 12 provides an alternating poling motion. In the diagonal stride 10, the arm 16 and leg 18 corresponding to a particular side of the body are generally moving in opposite directions. For example, when the right leg 18 has completed its kick and is beginning to move forward into its recovery stroke, the right arm 16 is just beginning to move backward into its power stroke. Accordingly, there is typically little “down time” when no forward motion is being generated. As a result, the diagonal stride 10 is well suited for slower snow conditions and terrain with an incline.
Referring to
The underside 30 of the ski 20 (the base 30) associated with each section 22, 24, 26 may be configured for its particular function. For example, the camber of the ski 20 ensures that the tip and tail 22, 24 are first to contact the snow 32. Accordingly, the base 30 of the tip and tail 22, 24 may be configured (e.g., waxed) for glide. The kick zone 26, on the other hand, may be configured for grip. For example, the base 30 through the kick zone 26 may be roughed or waxed to engage and grip the snow 32.
Referring to
Referring to
If the ski 20 is properly fitted to the skier, this downward force 38 should be sufficient to flatten the ski 20. Accordingly, the base 30 corresponding to the kick zone 26 may be pressed firming into contact with the snow 32 causing a frictional engagement therebetween. The skier may then propel himself or herself forward with respect to the ski 20.
The equal and opposite force 40 created by this forward propulsion may be opposed by a frictional force 42 acting between the base 30 of the ski 20 and the snow 32. The greater the downward force 38 generated by the skier, the greater the propulsion-providing frictional force 42. That is, the frictional force 42 is equal to the coefficient of friction (typically a constant for a given base preparation and snow condition) times the downward force 38. Thus, a powerful “kick” requires an effective weighting of the ski 20.
If the ski is altered to lessen the need for proper weighting thereof, the glide (speed) of that ski 20 will likely be compromised. For example, if the camber (spring constant) of the ski 20 is lessened, the base 30 may more easily be compacted against the snow 32. Accordingly, a strong kick may be produced with less effort. However, that also results in more of the kick zone 26 frictionally engaging the snow 32 when it is not wanted or needed (i.e., during double poling or downhill maneuvers). A similar result occurs when the kick zone 26 is lengthened. Thus, a fine balance between the camber of a ski 20, the length of the kick zone 26, and the weighting abilities of the skier is necessary to provide a fast ski 20 that also climbs well in the diagonal stride.
Referring to
If desired or necessary, more than one wheel may be positioned at each end 48, 52 of the roller ski 44. For example, “a first wheel 46” may be one of a pair of first wheels 46 positioned proximate the first end 48 of the roller ski 44 and spaced in the lateral direction 45 from one another. Similarly, “a second wheel 50” may be one of a pair of second wheels 50 positioned proximate the second end 52 of the roller ski 44 and spaced in the lateral direction 45 from one another.
In general, the first and second wheels 46, 50 may configured and positioned to rotate about axes extending in the lateral direction 45b. The axis corresponding to the first wheel 46 may be spaced from the axis corresponding the second wheel 50. Accordingly, in selected embodiments, the intermediate member 54 may extend substantially longitudinally 45a to connect the first wheel 46 to the second wheel 50.
In certain embodiments, an intermediate member 54 may include a first wheel mount 56 extending to engage the first wheel 46. A second wheel mount 58 may extend to engage the second wheel 50. A deck 60 may extend to connect the first and second wheels mounts 56, 58. The deck 60 may provide a location for securing a binding 28 to the roller ski 44.
Wheels 46, 50 in accordance with the present invention may be formed in any suitable shape. In general, the wheels 46, 50 may have a shape (e.g., width) selected to impart adequate stability to the roller ski 44. Wheels 46, 50 may be formed of any suitable material or combination of materials. For example, in certain embodiments, a wheel 46, 50 may comprise a rubber exterior formed around a metallic or polymeric hub. The hub may then support any appropriate bearing or axle 64.
In selected embodiments, the rubber used to form the wheel 46, 50 may provide a desired rolling resistence. For example, a softer rubber may increase the rolling resistance of the wheel 46, 50. Accordingly, the hardness of the rubber may be selected to provide a realistic snow-like resistance. Additionally, or in the alternative, the hardness of the rubber may be selected to provide a speed limiter reducing the speed achieved on downhill sections.
Wheel mounts 56, 58 in accordance with the present invention may be of any suitable type. For example, in selected embodiments, wheel mounts 56, 58 may comprise individual flanges 62 extending from the deck 60 to engage an axle 64 of the corresponding wheel 46, 50. Alternatively, the wheel mounts 56, 58 may each comprise a monolithic fork formed as a single piece to extend and bracket the corresponding wheel 46, 50.
Wheel mounts 56, 58 in accordance with the present invention may be formed of any suitable material or combinations of materials. Characteristics that may be considered in selecting suitable materials may include cost, availability, strength, density, elasticity, shock resistance, toughness, durability, corrosion resistance, and the like. In selected embodiments, suitable materials may include metals, metal alloys, polymers, reinforced polymers, and composites.
A deck 60 may be formed of any suitable material or combination of materials. Characteristics that may be considered in selecting suitable materials may include cost, availability, strength, density, flexibility, fatigue life, shock resistance, toughness, durability, corrosion resistance, water resistance, and the like. In selected embodiments, suitable materials may include metals, metal alloys, polymers, reinforced polymers, composites, woods, and the like. For example, in one embodiment, a deck 62 may be formed of a wood laminate. In other embodiments, a deck 62 may be formed to include a light weight core (e.g., a honeycomb core). In still other embodiments, deck 60 may be formed of a tubular metal material.
In selected embodiments, the wheel mounts 56, 58 may be formed of one or more materials dissimilar from those of the deck 60. For example, one or more of the wheel mounts 56, 58 may be formed of metal, while the deck 60 may be formed of a wood laminate. Alternatively, one or more of the wheel mounts 56, 58 may be formed of a material similar to that of the deck 60. For example, the wheel mounts 56, 58 and the deck 60 may both be formed of metal. In still other embodiments, one or more of the wheel mounts 56, 58 may be form as a monolithic (seamless) extension of the deck 60.
In operation, a roller ski 44 in may roll on a supporting surface 66 (e.g., road surface 66, trail surface 66). To simulate the diagonal stride 10, a stop 68 may be connected to the roller ski 44. The stop 68 may resists rearward roll of the roller ski 44 on the surface 66 in response to a force 38 of a threshold magnitude urging the roller ski 44 toward the surface 66 (i.e., a force of sufficiently magnitude and acting in the transverse direction 45c).
A force 38 of a threshold magnitude is generated and applied to the roller ski 44 by the user (skier). Accordingly, it is not susceptible to generic, across-the-board characterization. The magnitude may vary between different skiers and their corresponding weights and skiing styles. In generally, however, a threshold magnitude will be greater than one half of the weight of the skier. Also, in general, the threshold magnitude will be greater than the entire weight of the skier. However, different skiing styles may demand variations or departures from these general rules.
A stop 68 may have any suitable structural configuration to support the desired simulation. In selected embodiments, a stop 68 may resists rearward roll by engaging the supporting surface 66. For example, an intermediate member 54 may be cambered. This camber may cause the intermediate member 54 to act as a leaf spring, lifting the stop 68 away from the surface 66 when less than a force 38 of a threshold magnitude is applied to the roller ski 44.
As the force 38 increases, the camber of the intermediate member 54 may flatten, forcing the stop 68 closer to the surface 66. When a force 38 of a threshold magnitude is achieved, the stop 68 may contact and engage the surface 66. This engagement may resist rearward roll of the roller ski 44 on the surface 44. Accordingly, only after a full, proper weighting of the roller ski 44 may the skier generate a kick.
Furthermore, the strength of that kick (i.e., the strength of the frictional engagement between the stop 68 and the surface 66) will necessarily be depend on the downward force 38 generated and applied by the skier to the roller ski 44. That is, the resistance to rearward roll that is generated varies (e.g., proportionally varies) depending on the magnitude of the downward force 38. Using an electrical analogy, the resistance to rearward roll is analog, not digital.
The camber or spring constant of the intermediate member 54 may match the weight and skiing style of the user. Accordingly, a user may select an intermediate member 54 that will sufficiently flatten with the same downward force that such a user would generate using actual skis on snow. Thus, an intermediate member 54 suitable for one skier may be unsuitable for another. However, once matched, a roller ski 44 in accordance with the present invention may provide a close simulation to the kick achieved by that skier on snow.
For example, the present invention may include a method for matching roller skis 44 to a skier. The spring constant of a skier's actually classic snow skis may be tested. Particular attention may be paid to the downward force necessary to sufficiently urge the kick zone against an underlying surface. Then, an intermediate member 54 matching that spring constant may be selected or manufactured. That is, an intermediate member 54 may be provided that permits contact between the stop and the supporting surface 66 at the same force 38 (or nearly the same force 38) necessary to adequately flatten the kick zone of the snow ski.
Adjustments to an intermediate member 54 may be made to better match the desired spring constant. For example, the cross-section of the intermediate member 54 may be adjusted to fine tune the mechanical characteristics of thereof. Alternatively, or in addition thereto, the positioning of the stop 66 with respect to the roller ski 44 may be varied. Thus, the stop 66 may be positioned to contact the supporting surface 66 just as the resistence of the intermediate member 54 to further deflection reaches the desired level (force).
In selected embodiments, a stop 68 may have any suitable configuration. For example, in one embodiment, a stop 68 for contacting the supporting surface 66 may comprise a piece (e.g., block) of rubber secured to the underside of the intermediate member 54. In another embodiment, a stop 68 may comprise wheel 70 providing unidirectional rotation.
For example, the wheel 70 may rotate about unidirectional bearings, ratchet, or the like. The wheel 70 may be secured to roller ski 44 so that it resists rotation in the direction corresponding to rearward roll of the roller ski 44. However, in certain embodiments, the wheel 70 may be free to rotate in the direction corresponding to forward roll of the roller ski 44. Accordingly, should the wheel 70 inadvertently contact the surface 66 due to some irregularity therein, the wheel 70 will not undesirably stop the roller ski 44.
A stop 68 in accordance with the present invention may be positioned on a roller ski 44 in any suitable location. Suitable locations may include to the front of the binding 28, under the binding 38, to the rear of the binding, or the like. Similarly, the connection of the stop 68 to the roller ski 44 may be accomplished in any suitable manner. For example, in embodiments where the stop 68 comprises a wheel 70, an axle 72 may connect the wheel 70 to the roller ski 44.
An intermediate member 54 may be tailored to accommodate the stop 68. For example, in embodiments where the stop 68 comprises a wheel 70, an aperture 74 may be formed in the intermediate member 54 to accept the wheel 70. In certain embodiments, the thickness 76 of the intermediate member 54 in the transverse direction 54c may be increase to compensate for the structural weakness imposed by the aperture 74. In other embodiments, the width 78 of the intermediate member 54 in the lateral direction 54b may be increase to compensate for the structural weakness imposed by the aperture 74.
In still other embodiments, a stop 68 may comprise more than one wheel 70. For example, a wheel 70a, 70b may be positioned on each side of the intermediate member 54. In selected embodiments, the size of the wheel 70 may be decreased so that it may fit underneath the intermediate member 54 without the need for an aperture 74. For example, the size of the wheel 70 may be decreased such that a concavity in the underside of the intermediate member is all that is needed to accommodate the wheel 70.
In still other embodiments, a discontinuity 80 in the intermediate member 54 may accommodate the wheel 70. For example, a discontinuity 80 may permit the inclusions of stronger materials 82 (e.g., metals) to bridge the portion of the intermediate member 54 weakened by inclusion of the wheel 70.
Referring to
For example, in one embodiment, an intermediate member 54 may include one or more flex regions 84. A flex region 84 may permit a wheel mount 58 to move (e.g., translate, rotate, or some combination thereof) with respect to the remaining portion 86 of the intermediate member 54. A stop 68 may rigidly extend from the remaining portion 86 to a location over one of the wheels 50. Accordingly, a force 38 of a threshold magnitude may flex the flex region 84 sufficiently that the wheel 50 contacts the stop 68. This contact may result in a frictional engagement resisting further rotation of the wheel 50.
Again, the strength of the kick (i.e., the strength of the frictional engagement between the stop 68 and the wheel 50) will necessarily depend on the downward force 38 generated and applied by the skier to the roller ski 44. That is, the resistance to rearward roll that is generated varies (e.g., proportionally varies) depending on the magnitude of the downward force 38. Once the force 38 decreases sufficiently, the flex region 84 may resiliently return to a more neutral position, and the wheel 50 may again rotate freely.
Any suitable structures may be used to create a flex region 84. For example, in certain embodiments, biasing members 88 (e.g., pieces of spring steel 88) may connect a wheel mount 58 to the remaining portion 86 of the roller ski 44. In a neutral, unloaded position, the biasing member 88 may secure the wheel mount 58 in alignment with the remaining portion 86. However, when the roller ski 44 is urged against the supporting surface 66, the biasing members 88 may permit a parallelogram-type deflection of the wheel mount 58 toward the stop 68.
Referring to
Alternatively, in selected embodiments, additional degrees of control over the spring constant may be desirable. For example, an extension 90 may extend from the remaining portion 86 to engage the wheel mount 58. A resilient member or members 92 may provide the interface between extension 90 and wheel mount 58. Such a resilient member 92 may be comprise a metallic spring, elastomer, or the like. Accordingly, the spring constant of the flex region 83 may be determined by the biasing members 88, the extension 90, and the resilient member 92. Thus, by adjusting the spring constant of any of the various components 88, 90, 92, the overall spring constant of the flex region 84 may be tuned to a particular skier.
Referring to
In such embodiments, a force urging the roller ski 44 downward against a supporting surface 66 may induce a rotation 102 of the wheel mount 58 with respect to the remaining portion 86 such that the wheel 50 is urged toward the stop 68. A force 38 of a threshold magnitude may deflect the biasing member 96 sufficiently for the wheel 50 to contact the stop 68. This contact may result in a frictional engagement resisting further rotation of the wheel 50. This frictional engagement may vary with the magnitude of the downward force 38. Again, once the force 38 decreases sufficiently, the flex region 84 may resiliently return to a more neutral position, and the wheel 50 may again rotate freely.
In selected embodiments, the biasing member 96 of a flex region 84 may be sized, adjusted, or sized and adjusted to provided the desired flexure. For example, in selected embodiments, the biasing member 96 (e.g., a coil spring 96) may be selected accordingly to the expected loads to be applied thereto by the intended user. Additionally, the biasing member 96 may be preloaded. That is, the biasing member 96 may be held in a somewhat compressed state before a user ever applies any weight thereto. By preloading the biasing member 96, a certain amount of weight (downward force 34) may be applied to the roller ski 44 before any deflection of the biasing member 96 is achieved.
In certain embodiments, interfaces 103 may provide the connection between the biasing member 96 and the surrounding components 58, 86. In selected embodiments, the interfaces 103 may register the biasing member 96 with respect to the surrounding components 58, 86 through the use of apertures and corresponding posts sized to register therewithin. Also, by appropriately selecting the size of the interfaces 103, the amount of preload on the biasing member 96 may be controlled. For example, by selecting and installing thicker interfaces 103, the amount of preload may be increased.
Accordingly, through suitable combinations of biasing member 96 selection and preloading, the pivoting of the flex region 84 may be matched to an intended user. Thus, the flex region 84 may permit contact between the stop 68 and the wheel 50 at the same force 38 (or nearly the same force 38) necessary for the intended user to adequately flatten the kick zone of an appropriately fitted snow ski.
Referring to
As the chamber is flattened by a downward force 38, the ends 48, 52 of the roller ski 44 may be pushed apart. In that the tension member 108 is substantially inextensible, a rotation 110 may be induced in the brake pad 104. The mechanical advantage of the pivoting brake pad 104 may be selected such that a downward force 38 of some threshold magnitude may sufficiently flatten the intermediate member 54 such that the rotation 110 induced causes the brake pad 104 to contact the wheel 50 and resist further rotation thereof.
In selected embodiments, a stop 68 may include a tuner 112 to provide fine adjustments to the positioning of the brake pad 104. For example, in selected embodiments, a tuner 112 may provide the interface between the tension member 108 and one end 48 of the roller ski 44.
In one embodiment, a tuner 112 may include a bracket 114 connected to a wheel mount 56 by a pivot 116. An adjuster 118 may engage one end of the bracket 114. The tension member 108 may engage the other end of the bracket 114. Accordingly, manipulation of the adjuster 118 may cause the bracket 114 to rotate about the pivot 116. This rotation may then adjust the position of the tension member 108 and, consequently, the position of the brake pad 104. Thus, the tuner 112 may position the brake pad 104 so that it engages the wheel 50 at a desired deflection (e.g., flattening) of the intermediate member 54, with the desired downward force 38 associated therewith.
Referring to
Accordingly, as presented hereinabove, a stop 68 may comprise wheel 70 providing unidirectional rotation. Should such a wheel 70 inadvertently contact the surface 66 while traveling forward, the wheel 70 may simply roll over the irregularity without undesirably stop the roller ski 44. Alternatively, a less mobile stop 68 may also be configured to minimize the chance and extent of such undesirable stopping.
For example, in one embodiment, a stop 68 may include a block 120 of elastomeric material. The block 120 may have a channel 122 formed therethrough in the longitudinal direction 45a. The channel 122 may minimize the lateral 45b profile of the block 120 to decrease the probability of the block 120 inadvertently contacting an irregularity in the supporting surface 66.
In selected embodiments, the leading edge 124 of a block 120 may be tapered to provide a snow plow effect should the bock 120 encounter any movable irregularities (e.g., pebbles). Additionally, or in the alternative, a block 120 may be formed with slots 126 increasing the flexibility of the block 120. Accordingly, the slots 126 may reduce the abruptness and strength of any contact with an irregularity in the supporting surface 66.
In selected embodiments, the interface between a stop 68 and an intermediate member 54 may provide some adjustability. For example, should wear change the dimensions of a stop 68, a skier may be unable to obtain the desired kick. Accordingly, a spacer 128 may control the transverse 45c position of the stop 68. If desired, a stop 68 may be secured to an intermediate member by one or more fasteners 129 (e.g., removable fasteners such as screws, bolts, or the like). Accordingly, when a different kick is desired, a skier may remove the stop 68, insert a spacer 128 providing a desired change in transverse 45c position for the stop 68, and re-secure the stop 68.
Referring to
A base 130 may include a block 134 blocking rotation or pivoting of the foot 132 past a selected point. Accordingly, when a roller ski 44 in accordance with the present invention is weighted sufficiently, the foot 132 may contact the supporting surface 66. The skier may then move forward and by applying a rearward force 40 to the roller ski 44. Because of the frictional engagement between the foot 132 and the supporting surface 66, the rearward force 40 on the roller ski 44 may urge 136 the foot 132 against the block 134, thereby resisting rearward motion of the roller ski 44. A biasing member 138 may urge 136 the foot 132 against the block 134, thereby removing any slack from the system.
So embodied, a foot 132 may be free to rotate rearwardly 140, opposed in such a direction only by the biasing member 138. Accordingly, should the foot 132 undesirably encounter an irregularity in the supporting surface 66, the foot 132 may pivot rearwardly 140 without undesirably stopping or slowing the roller ski 44.
In selected embodiments, a stop 68 may include more than one foot 132. For example, in one embodiment, a pivot 142 may extend laterally through a base 130. A foot 132a, 132b may engage both ends of the pivot 142. Each such foot 132 may be manipulated by a corresponding block 134 and biasing member 138. In certain such embodiments, the feet may rotate independently on the pivot 142. Accordingly, each foot 132a, 132b may engage and release the support surface 66 independently.
A stop 68 comprising a base 130 and foot 132 (or feet 132a, 132b, etc.) may configured in any way to improve its operation characteristics. For example, the stop 68 may be formed of a lightweight material (e.g., metal, polymer, etc.). Portions of the material that are structurally unnecessary may be hollowed-out, thinned, or the like to lower the mass thereof. Also, a combination of materials may be used. For example, a foot 132 may include an elastomeric insert 144 providing the interface between the foot 132 and the supporting surface 66. The insert 144 may be replaceable should it wear excessively. Additionally, the stop 68 may include a interchangeable spacer 128 to compensate for wear, or to permit the stop 68 to contact the support surface 66 at a different weighting (e.g., heavier, softer, etc.).
A stop 68 configured to resist rearward roll by engaging the supporting surface 66 may be secured to a cambered, flexible intermediate member 54 as illustrated in FIGS. 6, 7, 16, and 17. Additionally, such a stop 68 may be secured to an intermediate member 54 including a flex region 84, such as those illustrated in
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.