Patent Grant
8220181
The present invention relates to the fields of sporting goods for athletic use, health and fitness equipment, physical rehabilitation, running, jogging, shock absorbing footwear, and the extension of ambulatory exercise benefits to persons with skeletal and/or joint infirmities that currently inhibit such activities because of the impact loadings therein comprised.
The health benefits of running, jogging and walking are widely known and have been well documented. An entire industry of sporting footwear, running apparel, and related periodical publications dedicated to enhancing these forms of exercise, has arisen in recent years, with the result of highly comfortable, shock absorbing footwear being available globally. These products share a common benefit over traditional footwear, namely increased cushioning or resilience without undue loss of lateral stability. The means by which this resilience is accomplished is almost universally the employment of elastomeric foam (air entrained in various elastomeric materials), or air bags, or both, for cushioning, typically in conjunction with somewhat oversized (principally overly wide) sole areas to offset the decreased lateral stability that the introduction of the cushioning material involves. Limitations of these traditional approaches in providing for increasing cushioning with operational safety include 1.) the rising spring rate inherent to elastomer-based compression springs, and 2.) the limited travel magnitude that can be employed before incurring excess loss of lateral stability. Numerous inventive proposals to increase shock absorption and resilience, over those of the so-called miming shoe, have been patented, some of which include efforts to deal with the loss of lateral stability inherent to the various cushioning mechanisms. None, however, provide practical (quiet, lightweight, and robust vs. wear) mechanisms for storing and releasing the kinetic energy of a runner's stride while dealing with the increased ankle-turning roll moment due to increased foot elevation, above the ground at impact, that increased cushioning travel entails, and while also providing for direction-of-travel motion control similar to that inherent to the human body's design architecture. Accordingly, there exists a need to overcome these current art limitations in order to improve both safety and enjoyability of these very beneficial forms of physical exercise, with the concurrent benefit of reduced impact loading magnitudes. 1 Lateral is defined herein as sideways, or in the transverse direction, where “Longitudinal” is defined as the fore-aft direction as typified by the long axis of the foot, and the direction of normal forward travel. For purposes of this text, “Pitch” or Pitching” is defined in common with aircraft terminology, as rotation about a transverse or lateral axis, i.e. in a forward rolling mode; “Roll” or “Rolling” is defined as tilt in the lateral direction, or rotation about a longitudinal axis, while “Yaw” will be understood to be rotation about a substantially vertical axis.
It is an advantage of this invention to simulate, to the greatest degree possible, the act of running on a hypothetical “endless” (or unbounded) trampoline, wherein vertical acceleration (of the runner's center of gravity) due to gravity is opposed by quiet, precisely controlled, long travel resilience of lightweight shoes over sufficient time duration as to maximize running efficiency and comfort.
It is a further advantage of this invention to enable lateral acceleration, with minimal torque on the runner's ankle due to the additional height required by the above long travel resiliency advantage, simulating the cornering capability of a hockey skate while yet providing normal ground contact area for the “flotation” needed for disadvantage-free operation on loose or compressible ground surfaces.
It is a still further advantage of this invention to enable normal-feeling and acting toe articulation action and feedback for normal forward motion control efficiency and balance under all operating conditions, including the climbing of steep slopes in directions that include bias with respect to the fall lines of said slopes.
It is yet another advantage of this invention to operate with freedom from resonance or flapping of components.
It is still another advantage of this invention to provide for cooling of the sole area of the wearer's foot, to enhance comfort and reduce buildup of potentially deleterious moisture during use.
It is further still an advantage of this invention to provide for comfort and running efficiency by minimization of shoe mass and inertia.
It is a benefit of this invention to avoid inward protuberance of hardware that would reduce normal miming clearance between shoes.
It is a further benefit of this invention to provide an optional mechanism for stabilization of a normally-articulating ankle against roll mode torques on the ankle joint that might occasion severe lateral accelerations, and to integrate the stabilization into extended travel variants of the invention.
It is finally an objective of this invention to provide freedom from wear and deterioration of mobile interfaces and clearances over time.
The storage and transfer of the bulk of the energy of landing of a runner's stride to the point of usefulness during toe-off requires an appropriate combination of both resilient spring rate and travel capability. If this combination does not correspond sufficiently to the runner's weight as to produce the appropriate vibratory sub-period, or time interval during which the spring is compressed, then either bottom-out, due to insufficient travel for the spring rate, or else premature release in the case of too-stiff a rate, will occur. Additionally, as has been recognized by Rennex, U.S. Pat. No. 6,684,531, the resilient compression effected by heel strike must also result in compressed metatarsal-region structure, in order to be available for resilient release during toe-off The maintenance of pitching mode attitude of ground contact member (hereafter “GCM”) to being substantially parallel to the plane2 of the shoe sole member (hereafter “SSM”) is thus dictated in conjunction with resiliently-urged downward motion of the GCM. This substantially parallel-to-SSM GCM functionality essentially replicates the action of a trampoline, wherein an effectively “single degree of freedom” spring member is equally useful to both heel and toe. Devices which lack this substantial parallelism, such as e.g. Schnell, U.S. Pat. No. 4,534,124, are able to provide some compressive resilience and rebound assistance for running, but are disadvantaged by their lack of pitching mode stiffness, wherein the toe-off spring rate is too low for push off effectiveness, as well as for direction-of-motion balance and control. Devices having distributed, or multiple independent local compliances may enhance comfort, but lacking the unitized motion control by which compression of the heel region also compresses the metatarsal region, i.e. enforced pitching mode parallelism between the resiliently urged GCM and the plane of the SSM, such devices are simply unable to store heel strike energy for release during the toe-off phase for increase of running efficiency. 2 The plane of SSM is herein defined as having the same relationship to the user's foot as has a uniformly padded or cushioned horizontal surface upon which a barefooted user has achieved static balance while standing on the foot with which the SSM is associated.
The shortcomings of prior art in comparison to this substantially parallel-to-SSM GCM motion control have been adequately summarized by Rennex and are herein incorporated by reference. The Rennex configuration, however, while an intended efficiency improvement, includes substantial risk of ankle injury due to side loading, in that the GCM's “non-tilt” parallelism to the SSM applies not only to the pitching mode (as seen, for example, in a side view), but also to the roll mode (as seen in a rear or front view), wherein it acts to generate ankle-turning3 roll mode moment loading as the GCM attempts to “square up to,” or attain full contact with, a sloped or uneven treading surface. 3 The terminology “ankle turning” is herein used in the sense of common usage, i.e. a “turned ankle” being one that has been accidentally injured by overextension in the roll mode, usually a result of encountering a situation that loads the ankle with the shoe sole becoming excessively out of square, laterally, with the lower leg.
Additionally, the Rennex apparatus lacks energy efficiency in the critical toe-off phase foot orientation because, while allowing for natural metatarsal joint flexure, it does so with the GCM remaining flat on the ground. In this orientation, whatever resilient urging may remain of the GCM compression of heel strike can only be released in a vertical (or normal to treading surface) direction. At toe-off the user's foot and lower leg are rotated forward. To be maximally useful for running efficiency, GCM resilient urging should be “soft” enough to remain active throughout the stride cycle's ground contact phase, i.e. with some residual compression and resilient urging remaining for the final toe-off phase when the foot and lower leg are rotated forward, and the residual urging should be directed normal to the plane of the SSM or parallel to the shin such that its rearward resultant helps propel the user forward, countering the anti-propulsive energy absorbed at heel strike when the lower leg is rotated backwards. The “vertical” lifting to which the Rennex GCM is limited is of minimal propulsion benefit to a forward-leaning limb, and the abrupt “catch-up” acceleration of a flat-laying resilient urging mechanism from horizontal, to the parallelism-to-SSM needed in time for the next heel strike, represents a distracting if not dangerous “flapping motion” which introduces a whole new range of problems.
Ankle-turning moment loading is a naturally-occurring event which, in the case of conventional shoes, results from sideways slanting of the shin with respect to the local ground, or treading surface area under the GCM. To the extent that the shin (herein and hereafter used as descriptive substitute for a line between the knee and ankle joints and thus the laterally nominal direction of force transfer) is not laterally normal (perpendicular) to the local slope or attitude of the treading surface, the (nominally normal to shin, roll mode-wise) shoe sole encounters edge loading as weight or force is applied. The lateral offset of the first-contacting sole edge from the ankle joint's lateral or roll mode center of rotation, as measured normal to the loading direction, i.e. the shin, constitutes a moment arm length which, in conjunction with applied weight or force, endeavors to torque the shoe sole towards parallelism with the treading surface. This lateral torque, or roll moment, is, in the usual case of conventional shoes on suitably navigable terrain, subsequently limited in its ability to “turn” the ankle in roll mode pivoting by the shoe sole's attaining parallelism with the treading surface, wherein the initial edge loading becomes counterbalanced by other areas of the shoe sole acting to centralize the load to having resultant location with smaller offset from the ankle joint's roll center.
In the case of an extended or displaced (with respect to SSM in its free state) “non-tilting” GCM such as Rennex, the roll moment relief associated with GCM lower surface attainment of parallelism to treading surface comes only after the roll mode moment arm (as defined by the distance between loaded edge of GCM and loading line or “shin”), which works to turn the ankle, has been increased by virtue of the increased free state distance from GCM lower surface to the ankle joint.
At high values of lateral acceleration or treading surface slope, i.e. high lateral tilt angles of shin with respect to treading surface attitude, the non-tilting GCM lower surface extension height beyond that of a normal shoe represents increased risk of ankle turning injury. The roll moment initiated by sole edge offset from the shin must increase in magnitude, as the sole begins to “square up” with (or become parallel to) the treading surface, because the added height of the ankle, above the free-state extended GCM lower surface, causes the ankle to travel further laterally (away from the loading direction between knee and sole edge) as the GCM and foot pivot about the first-contacting edge of the GCM towards parallelism with the treading surface.
The present inventive introduction of a ground-level longitudinal pivot axis relieves the magnitude of the roll moment required to “square up” the GCM lower surface to the treading surface, by substituting, for the above-described increased ankle turning moment, a substantially lighter moment from the predetermined spring rate resilient urging of the GCM's roll attitude, toward parallel with plane of SSM, about its inventive ground level longitudinal pivot axis, the pivot allowing the ankle to experience a situation much closer to the nominally roll-neutral characteristics of in-line roller skates or ice skates. The predetermined roll mode spring rate of the GCM's pivot axis is preferably high enough to provide some support to counteract the “wobbly ankles” instability typical to the beginning stages of learning to ice skate, while remaining low enough to avoid the substantial risk of ankle turning roll moments posed by non-roll-pivoting prior art GCMs.
Further ankle joint protection for so-called “extreme” activities is provided as an optional construction for moderate travel embodiments of Full Suspension Footwear, but is fully integrated into extended travel embodiments for user safety. This inventive protection provides, in both cases, a substantially single degree of freedom transverse ankle pivot axis (hereafter “TAPA”) adjacent, and substantially coincident with, the user's ankle joint's pitching mode pivot center, the TAPA being defined by bearing members fixedly associated with both the SSM and a shin brace member (hereafter “SBM”) which, by connective association with the user's lower leg preferably just below the knee, resists or carries roll moment loadings due to ground contact. The TAPA bearing member's fixed relationship to the SSM assures, in conjunction with the SBM, the “laterality” of the TAPA, preventing its rotation or migration away from adjacency to, and axial coincidence with, the user's ankle joint. These ankle joint protecting embodiments assure that GCM extension travel remains laterally in line with the shin and so free from the increases in ankle-turning roll moment that extended GCM free-state displacements from SSM inevitably cause in non-tilt apparatus lacking such ankle stabilization.
In the context of such ankle stabilization where GCM lateral alignment with shin is assured, even absent roll mode pivoting of the GCM, the roll moment arm influencing the TAPA bearing members due to GCM edge loading remains essentially constant regardless of GCM extension magnitude with respect to SSM, being simply the GCM lower surface's edge offset distance from the shin axis. At high values of free-state GCM extension, this fixed moment arm value represents a diminishing portion of the moment loadings at the knee and hip joints associated with lateral motion control efforts: in this light the extended travel embodiments, with their integrated ankle protection, are safely provided without, as well as with, roll pivoting of GCM. Slight rounding of the GCM's lower surface in the non-pivoting case can provide load centralization laterally sufficient for even extreme use situations since the TAPA protects the ankle joint, and since the roll moment arm is not greater than that of the conventional shoe, even with a flat GCM lower surface of similar width.
In the above discourse, the Rennex (U.S. Pat. No. 6,684,531) configuration has been accorded functionality per apparent inventor intent, but in reality the so-called “P-diamond” therein disclosed lacks stability in the longitudinal direction and so is unsuitable for safe pedestrian use.
Accordingly, the inventive Full Suspension Footwear herein disclosed achieves advantages over, and avoids the limitations of, prior art mechanisms by providing:
A GCM whose motion or degree of freedom with respect to its associated SSM maintains substantial pitching mode parallelism for agility and control, with extension motion prescribed and precisely controlled to being substantially linear translation away from either the SSM, in direction normal to same, in the case of moderate travel embodiments4, or the user's knee, in direction parallel to the shin, in the case of extended travel embodiments, with extension motion furthermore being urged resiliently to a free state location that provides for substantial compressive and rebound travel with respect to the user's ankle joint. 4 Having, for instance, GCM displacement travel capability on the order of ¼ the length of the user's foot.
The GCM is preferably capable of pivoting, or rolling, with respect to the SSM and with appropriate restoring torque, about a longitudinal axis located at or near its lower, ground-contacting surface5, until it has reached the state of being oriented parallel to and in tractive contact with the ground. 5 And preferably laterally centralized with respect to said GCM's width or area.
The GCM preferably also has an articulating toe pressure member (hereafter “ATPM”) at its front end to replicate the action of human toes pivoting about their metatarsal joints at the ball of the foot. The GCM ATPM preferably also is in substantially friction-free connectivity with an angularly mobile toe support member (hereafter “AMTSM”) comprising a forward portion of the SSM such that substantial “parallelism” of angular attitude and motion is maintained between the ATPM and AMTSM for the transference of force and motion, i.e. so that an upward deflection of the GCM's ATPM pushes the SSM's AMTSM upward, and a downward toe force by the wearer is reflected as a similar downward force at the ATPM region of the GCM's sole.
An optional (in case of moderate travel embodiments) lateral, or roll mode, torque-resisting SBM having a TAPA bearing adjacent the wearer's ankle joint to allow for normal articulation of the ankle joint while bracing the SSM laterally with respect to the lower leg is provided. This lateral (or roll) torque-resisting SBM becomes increasingly important for operational safety in case of either aggressive sideways (or lateral) acceleration or longer-travel configurations or both.
In extended-travel embodiments, this torque-resisting SBM is utilized as an integral element of a travel apparatus which replaces motion substantially normal to the SSM's sole with motion substantially parallel to, and in the longitudinal direction of, the user's shin, for improved operational control. The shin-direction GCM motion becomes necessary for the configurations with extended travels because the normal-to-sole motion most practical for moderate travel capability embodiments would incur stability and control problems, in case of the large GCM offsets from the user's ankle joint that are necessarily associated with these extended travels, due to the necessarily large ankle articulation-based longitudinal displacements of the GCM with respect to the shin. Such a combination of large GCM extension with travel normal to the plane of the SSM would subject the ankle joint to abnormally high pitching mode moments, as the overly-large GCM displacement from ankle joint would represent a large moment arm about the ankle joint.
These and other features and advantages of the present invention will become apparent from the following description of the invention, when viewed in accordance with the accompanying drawings and appended claims.
Various mechanisms may be employed to produce the inventive functionality of moderate travel Full Suspension Footwear, including miniaturization of apparatus preferred for extended travel functionality. In the interest of brevity, and given that the simplest means of achieving a given end is often the best, descriptions of apparatus for moderate travel functionality will be limited to two preferred-for-simplicity embodiments.
Four-bar linkages are well known in the art for maintaining precise control of a wide range of prescribed motions. The simplest four-bar linkage configuration, substantially a parallelogram configuration, is hereby disclosed in conjunction with shoe structures as perhaps the most practical mechanism for the extension-away-from-SSM motion, with parallelism to plane of SSM, needed for a moderate travel resiliently urged GCM to be effective in storing the energy of landing in such a way as to be useful for takeoff during forward travel. This substantial parallelism-to-sole is in the longitudinal sense, i.e. in the pitching mode, such that heel compression travel generally equals toe rebound travel. By the employment of differing length pivot links, however, the four-bar mechanism can prescribe a combination of translation and rotation that can, for example, give the toe end of the GCM somewhat greater vertical travel than that of the heel end, effectively changing their respective spring rates. In this given example, the heel strike phase of motion, with compressive force being applied at the heel end, would exhibit a stiffer spring rate than the toe end, whose rebound would exhibit a softer rate over its longer travel, at probable benefit to running efficiency.
At least two adjacent pivots of a four-bar linkage system must maintain axis alignment (parallelism) in order for the mechanism to constrain motion to a single plane, while ideally for stress distribution all four pivots would maintain axis alignment. In the present usage of a four-bar linkage (hereafter alternatively “FBL”) to control the motion of a mobile GCM or assembly, it is required, for yaw control of the GCM, that the at least two adjacent pivots which maintain axis alignment share a common link between the SSM and the GCM. For the remainder of this document, all references to FBLs will be interpreted as meaning in-plane type FBLs, and all references to pivots will be considered to mean substantially rigid in terms of axis alignment control, and associated resistance to out-of-plane bending or twisting.
A preferred embodiment of the application of FBL technology to moderate extension travel Full Suspension Footwear is to have at least two pivots of a common link comprise elastomeric torsion bushings of high aspect ratio (i.e. large ratio of length to elastomer section thickness) which, besides eliminating the clearances, noise, and wear opportunities of conventional pivot bearings, can provide (on a distributed basis, again for ideal stress distribution) the restoring torques required for resilient travel action without need for additional spring mechanisms, while also providing some of the hysteretic motion damping required for substantial freedom from resonant vibrations of the structures being controlled. The function of the high aspect ratio feature of the elastomeric torsion bushings is to provide high stiffness to bending loads, and thus precise motion control, by resisting lateral (roll and yaw mode) deflections, or in other words, to act like rigid pivot bearings having axis alignment control capability.
The resultant pivot bearing functionality is superior, for the limited rotational travel requirements of this application, to conventional type pivot bearings in the composite of noise and vibration, wear resistance, and total mass, while lending itself to working with the tapered pivot pin configuration that mass-optimized pivot links dictate for improved uniformity of bending stress distribution. Round section torsion bushings are preferred for their nearly linear torsional spring rate (because torsional stresses are purely in shear), but alternative non-round sections (e.g. elliptical, wherein compressive stresses are introduced under torsion), may be employed to provide for rising rate functionality as may be desired for a specific application.
A preferred configuration FBL for moderate travel Full Suspension Footwear has transverse SSM pivots in a substantially vertical array in the metatarsal joint region, with the lower pivot just under, or imbedded in, the SSM and the upper pivot elevated above the metatarsal region, the two pivots being stiffly constrained in substantially fixed relationship to a foot-capturing shoe portion and to each other. Substantially horizontal pivot links extend longitudinally rearward to mobile frame member transverse pivots also in substantially vertical array and with fixed relationship to each other by virtue of being fixedly housed in the mobile frame member.
The mobile frame member extends downward from its transverse pivots to below the SSM's sole when the pivots are at their maximum upward limit of travel, to become, or be joined to, the GCM, extending forward in substantial parallelism to the SSM's sole. In this preferred configuration, however, the mobile frame member's horizontal portion is a forward extension, which serves as the structural support member of the pivot bearing for the roll mode degree of freedom that the GCM preferably provides. This longitudinal roll mode pivot is also preferably a high aspect ratio elastomeric torsion spring for quietness, wear freedom, motion control, and integration of torsional spring rate. This longitudinal pivot spring preferably comprises a cylindrical element cross-sectional shape for linearity of torsional spring rate, but may also employ non-cylindrical elastomeric sections for rising torsional rate at the discretion of the designer.
A non-rotating GCM relationship to the SSM is herein also disclosed, in conjunction with motion control apparatus differing from prior art, but this embodiment is not preferred because of the increased roll moment loading on the ankles that an increased-travel shoe device entails. Preferred for freedom from roll mode torque on the ankles is the application of force in line with the shin bones, as is the case with ice skates and roller blade (or in-line roller) skates. Accordingly, a near ground level longitudinal pivot axis is disclosed, to enable the GCM to “square up” with the ground surface without requiring the exaggerated lateral deflecting of the ankle (to being outside the line of loading), as is the problem with current art. This inventive advantage becomes increasingly important as lateral acceleration levels (from cornering loads or lateral movement) increase, or as ground surface slopes are encountered, or as extension travel is increased. Current art designs providing high degrees of resilient cushioning travel are not practical for most sports, which typically include the need for lateral agility. A light restoring torque on the disclosed roll mode pivoting GCM is desirable to maintain in-flight parallelism to the SSM's sole, and is again preferably provided by an elastomeric torsion spring (hereafter alternatively “ETS”) for the previously cited advantages of light weight, quiet operation, freedom from wear, and optimum hysteretic motion damping.
The roll mode pivot axis is not required for GCMs which by nature pivot at the ground contact interface. Ice skate blades and “roller blades” or in-line roller skate wheels exemplify this special class of inherently ankle-protecting GCMs. It will be understood that the articulating toe pressure member or ATPM of a roller blade type GCM will comprise at least one forwardly-located roller that is vertically mobile with respect to the at least two rearward GCM rollers, while maintaining substantial axis alignment with them.
The two substantially horizontal longitudinal FBL pivot links can be configured to be two-sided, or closed-loop, structures to maximize stiffness for given pivot diameter and material properties, but this configuration violates the previously-stated design benefit of avoiding any inward protuberance. Consequently, a single-side link configuration is preferred, using tubular pivot links of sufficient bending stiffness as to assure appropriate pivot axis alignment. The pivot pins of these links are preferably tapered, for improved uniformity of the bending moment stresses they carry, from larger diameter, at their transition from transverse to longitudinal, to smaller diameter at their free (inner) ends, in order to provide the requisite high torsional and bending stiffnesses at minimum mass. This tapering can also aid the manufacturing assembly process of minimum mass embodiments, where the bonding of elastomeric bushing material directly to mobile frame member pivot housings and pivot link pivot pins can avoid the squeegee effect that would otherwise try to strip bonding cement from the preferably compressed section of a purely cylindrical bushing as it traveled to its final position, and it further avoids the residual assembly shear stresses within the elastomer, which would otherwise require overtravelling at assembly to only partially overcome. Cartridge type bushings, preferably mold bonded to thin wall sleeves prior to press-fit assembly to pivot housings and pivot link pins, would allow for interchangeable bushings in order to vary spring rate, at a modest penalty of increased mass. The thin wall sleeves preferably comprise fine-pitch splines to maximize the ratio of torque capacity (with respect to their mating components) to axial installation and retention forces. The cartridge type bushings may be retained securely seated to their (preferably) respective tapers by threaded fasteners for added joint integrity. The fasteners are preferably applied to the pivot pin's small end inside diameter and the pivot housing's large end outside diameter.
An optional FBL configuration, with the SSM's fixed pivot axes located in the heel area and the mobile frame member's pivot array located forward of the heel area is clearly also possible as means of providing the prescribed substantially vertical motion control and so is herein disclosed, but without preference, as this configuration tends to produce heel end spring rates softer than toe end by virtue of the elastic compliances of member components, a condition exacerbated by the slight radial deformations of the preferred high aspect ratio elastomeric pivot bushings themselves, where used.
Many alternative combinations of pivot bearings and restoring springs will be understood to be included in the FBL motion control mechanism herein disclosed in conjunction with a moderate travel SSM. As an example, a single torsion spring could be located at the above-metatarsal pivot, while the three other pivots could be simple axis alignment maintaining bushings, leaf spring type pivots or anti-friction bearings. In this case, the torsion spring can be an easily interchangeable cartridge-type unit that allows the spring rate to be changed for differing severity of use, or even for different users. The torsion spring is preferably elastomeric, for known energy storage advantages over other (e.g. steel hairpin) spring configurations, this advantage being true in comparison by individual characteristics such as mass, packaging space, and design efficiency of torque transmittal means, so certainly true in the composite sense, but alternative spring configurations, whether linear or torsional, will be understood to be included in the disclosed resiliently urged four-bar linkage concept.
Elastomeric torsion springs of many configurations are known, with mold bonded springs, especially, offering great design flexibility as required to accommodate packaging constraints. The most generally useful types are of axi-symmetric (i.e. with purely shear loading, absent compression loading, when under purely torsional displacement) configuration, wherein the elastomeric spring element is bounded by, and typically bonded to, high stiffness circular section torque transfer members which distribute the shearing loads to the elastomer section. The most common forms, cylindrical bushings, uniform numerical shear stress bushings, and disc types, have straightforward mathematical relationships between torsional shear strain, torsional shear stress, and torsional stiffness or spring rate.
Hybrid configuration elastomeric torsion springs, such as the generally L-shaped cross-sectional combination of disc-type and cylindrical bushing type sections are also commonly used, for example in mold-bonded torsional vibration dampers (or “TVDs”) that are used on certain automotive and industrial internal combustion engine crankshafts to prevent fatigue failure. The disc sections of these hybrid springs are typically of the preferred “common vertex” construction that is well-known to have the durability advantage, especially in the special case of axial symmetry about a plane normal to the torsion axis, of substantially uniform torsional shear stress and strain throughout the elastomeric section. The cylindrical cross-section portion of these hybrid springs both adds to the spring's radial stiffness, and facilitates the molding process. The radiused “elbow” transition region between the common vertex disc spring section boundaries and the cylindrical section's axially oriented section boundaries is not so mathematically straightforward, engineering wise, but does represent an important-to-packageability class of the prior art which modern modeling techniques such as finite element analysis (or “FEA”) can readily optimize.
In this present TVD example, the preferred, most straightforward, and most typical design practice is for the boundaries of the transition region to be formed by radii having tangency to the cylindrical section's boundaries at a common axial location, and then tangency to each, respectively, of the diverging disc face section boundaries. In so doing, these radii form gradual transition of elastomer section width and shape from parallel-sided in the cylindrical region, to tapered at the common vertex disc spring's divergence angle in the disc region, a configuration which, by avoiding stress concentrations due to excessive convexity of too-small a radius at the “inside” radius tangent to the outer boundary of the cylindrical section, can result in favorably uniform distribution of torsional shear stresses throughout the transition region, the convexity acting to increase the stresses adjacent the normally lowest-stress outer boundary of the cylindrical section, and the opposite boundary's concavity acting to decrease the stresses adjacent the normally highest-stress inner boundary of the cylindrical section, as is known by those of skill in the art.
Such cross-sectional transition regions of current art springs, or portions thereof, may be used with various proportionalities to the packaging advantage of reduced pivot link length, and thus reduced torsional spring rate requirements, by facilitating the “necking down” of spring diameter in order to provide operating clearance in the heel bulge and instep crown regions of Full Suspension Footwear FBL pivot locations, while retaining the spring rate advantage inherent to larger diameter regions. In cases where only portions of such transition regions are utilized, i.e. less than a full 90 degree turn, it is preferable to approximate, by choice of elastomer section free end configuration, the uniform numerical stress configurations known in the art wherein the free end configuration of elastomer section assumes the appropriate orientation that, depending on extent of portion utilized, changes from substantially axial at and beyond the “vertical”6 disc tangency portion of the corner, to substantially that of the “uniform numerical stress” contour known to be ideal for purely cylindrical sections, and preferably also inclusive of the large bond line stress reduction fillets which are known in the art to be beneficial to flex life. 6 In the case of horizontal orientation of torsion axis.
The back-to-back union, at the cylindrical bushing ends of similar but mirrored transition corners to form outwardly concave, or “U-shaped” spring sections will be recognized to be obvious utilization of these known prior art configurations, whether or not inclusive of substantial length of purely cylindrical section, and whether contiguous or separated axially at the mirroring plane.
The second preferred-for-simplicity moderate travel embodiment is apparatus using at least one linear bearing (or plunger) structure having substantially normal-to-plane-of-SSM travel orientation, preferably located in the metatarsal region for freedom from packaging space interference with ankle mobility, which by design is able to constrain motion to a single degree of freedom, i.e. substantially without pitch (unless by design for heel vs. toe rate differential as discussed above), yaw or roll rotation with respect to the normal-to-plane-of-SSM direction of linear motion. Two plungers of cylindrical type (which individually would permit yaw rotation) suffice this motion control, and are packageable in array either beside the metatarsals on the outside of the foot or on both sides of the foot; in order to fulfill the “no inward protuberances” benefit in the latter case of both sides of foot packaging, the innermost plunger would preferably be located in the region just above the “big toe” metatarsal joint. As a preferred alternative to the twin plungers for yaw control, a single yaw rotation-prohibiting plunger may be employed, in this case preferably located in the outer metatarsal region having outboard (i.e. around the little toe metatarsal region of the SSM) connectivity to the GCM, or roll pivoting GCM assembly, below the SSM. Such rotation-prohibiting linear bearing mechanisms are known, e.g., the so-called Head Shok front suspension of the popular Cannondale mountain bike line, in which a single unitized front fork translates on anti-friction needle roller bearings within, and without rotation with respect to, a handlebar-controlled portion of the steerer tube. An apparatus for controlling motion to substantially linear translation, with substantial freedom from yaw, pitch or roll rotation, will herein and hereafter be referred to as a linear bearing member assembly, or “LBMA”, and will be understood to be capable of being employed singly alone, with as-defined functional property of the ability to maintain substantial freedom from yaw rotation of extension member.
The LBMA in the present instance of moderate travel Full Suspension Footwear would have travel direction preferably leaned very slightly forward (from normal to plane of SSM) to effectively stiffen the compressive spring rate experienced by heel strike while softening that of toe-off slightly, for probable kinematic advantage to a runner. A preferable means of resilience for such LBMA architecture is the use of so-called wave springs, which offer packaging density and mass penalty advantages over coil springs, but hairpin springs can also serve at reduced mass penalty. Gas springs may be chosen in case the broader usage applicability of rising rate springs were to be prioritized over the generally gentler linear rate case, and elastomeric tension springs deserve consideration for their composite of design characteristics as well. Elastomeric tension springs including externally-accessible rubber bands or surgical tubing segments are useful to facilitate ease of spring rate adjustment, but suffer increased vulnerability to environmental hazards including ozone cracking.
In any case of GCM motion control mechanism it is desirable to “preload” the resilient urging, by means of a travel limiting mechanism such as at minimum a flexible tensile member and/or an elastomeric bumper stop, so that working extension travel is minimally wasted on the need to reach static equilibrium with gravity. Travel limitation including “shock absorption”, such as is known, combining viscous rebound motion damping in conjunction with resilient urging back towards free-state location, is preferably employed to enable the otherwise abrupt deceleration7 at the end of toe-off to be less noticeable by virtue of more effective travel limitation cushioning. The entire “airborne” foot travel time between toe-off and heel strike is available for the process of slowing and returning, after overtravel, the GCM to a predetermined free-state extension magnitude: the more of this time period that is used for GCM free-state location stabilization, the less abrupt and distractive the toe-off acceleration8 of GCM to following the departing SSM will be. Preferred, therefore, for controlling GCM mass at toe-off is a travel limiting apparatus with soft enough spring rate to allow transient overtravel of GCM to extension values beyond its free-state equilibrium location, and viscous “rebound damping”, preferably in the return direction only, of magnitude near critical to manage the return travel (between overtravel and free-state locations) as gradually as possible while assuring completion within the characteristic “airborne” phase of a runner's stride, and substantial freedom from resonant behavior. 7 With respect to SSM as it abruptly departs from treading surface contact.8 From at-rest in contact with treading surface, or deceleration with respect to “departing” SSM.
A key element of forward motion control and efficiency engineered into the foot of the human body is the action of the toes, as hinged about their joints with the metatarsals in the ball of the foot and urged by muscle structures. Principal loads are carried by the bail of the foot during the running stride, but balance and forward impetus both receive key contributions from toe loading and articulation flexibility, with the so-called windlass mechanism engineered into the foot's structure acting to brace the arch for effective transference of calf contraction into metatarsal downward urging. Additionally, the toe region becomes the principal ground contact area and source of balance in the climbing of steep slopes, so high performance footwear must preserve this key toe articulation functionality.
The angular deflectability of the SSM's AMTSM preferably parallels that of the user's foot, by having effective pivot axis in proximity to that of the toes in order to avoid chafing or shearing stresses at the shoe-to-foot interface. The angular deflectability of the GCM's ATPM may, like that of the SSM's AMTSM, be by means of any form of hinge or pivot, including the bending of thin cross-section materials in leaf spring fashion. Preferred for purposes of this disclosure is a piano-type (i.e. full width) ATPM hinge comprising elastomeric bushings that share a common axle in order to possess inherent restoring torque, as well as the other elastomeric torsion bushing advantages cited previously.
Apparatus for converting the angular motion of the GCM's ATPM into a form readily transferred to the SSM's AMTSM, and nearly friction-free conveyance of this motion to be converted into angular deformation of the SSM's AMTSM is also herein disclosed. Numerous mechanisms can achieve this disclosed functionality, e.g. a cable with an end anchored in the GCM's ATPM and which passes below its pivot axis by riding on ATPM pivot housing surfaces that perform the function of a pulley, i.e. to maintain the cable at a radially displaced distance from the pivot axis, so as to transform ATPM rotation into cable axial translation. The cable's axial translation direction is then reversed, substantially free from friction, by a reverser pulley member pivoting about a “knife edge” or equivalent low friction rocker bearing at the rear of the mobile frame member, to then continue forward to engage a pulley-like hinge housing member of the SSM's AMTSM that maintains the cable at radial displacement above the pivot axis of the AMTSM, and to finally be anchored in the SSM's AMTSM itself. The drive ratio of the thus-configured three pulley motion transfer mechanism can be varied by changing the location of the reverser pulley member's pivot with respect to the cable runs, even to the extent of being made continuously variable by choice of pulley groove contour.
Alternative motion control mechanisms include flexible coiled compression sheath control cables at friction penalty, but with packageability benefits.
It is understood that axially stiff tension members (or cables) and pullies represent special cases of FBLs, being interchangeable functionally whenever a link (or bar) can be configured so as to be subjected to only tension.
Dual conjoined FBLs (or CFBLs, as further detailed later), may be utilized adjacent the (substantially horizontal) longitudinal pivot links for ATPM/AMTSM parallelism control while accommodating GCM/ATPM assembly roll mode pivoting, by attaching the substantially vertical lower terminal link to the ATPM with a flexible coupling that, like a Cardin (or “Universal”) joint, provides angular or torsional stiffness in the plane of the CFBL while accommodating angular flex or misalignment in a plane normal to the GCM roll axis.
The open space between SSM sole and GCM represents both challenge and opportunity. A challenge to avoid encroachment of foreign objects such as stones from the “mastication space” between soles is preferably addressed by a resilient mesh curtain being sealingly arrayed around the periphery of the soles. The opportunity to increase wearer comfort by ventilation of the SSM's sole is embraced by providing sole member perforations in communication with the open space and is disclosed in combination with other Full Suspension Footwear inventive elements. Further, independently claimed sole cooling structures, in combination with the Full Suspension Footwear inventive elements, but also useful for sport shoes of other types such as cycling, include longitudinally oriented air guide channels, such as might be formed by aluminum extrusion, in and/or as part of the sole member, in conjunction with sole member perforations to enable pumping/breathing action with foot motion, to conduct air through the sole perforations for moisture transfer and convective/evaporative cooling in addition to the conductive cooling benefits of a high thermal conductivity material such as aluminum being utilized to comprise the air cooling channels. These longitudinally oriented air guide channels preferably provide air through-flow capability by means of being flowingly connected with open areas at both of their ends.
The disclosed preferably configured moderate travel Full Suspension Footwear, having both toe articulation functionality and ice skate-like roll mode pivoting of GCM will be understood to be capable of easily negotiating steep, off camber slopes (such as climbing diagonally across a highly sloped surface such as a roof) without either loss of balance, or requirement for awkward unnatural angulations of ankle joints, a clear operational advantage over previously-disclosed current art. Construction from lightweight high strength materials such as carbon fiber promises, in conjunction with the inherently low mass of high aspect ratio elastomeric torsion bushings, to result in high performance Full Suspension Footwear having minimally more mass than the best of current-art running shoes.
The two preferred-for-simplicity embodiments disclosed for the maintenance of prescribed inventive moderate travel embodiment GCM motion with respect to SSM, namely FBLs and non-rotating linear bearings, certainly do not exhaust the large variety of mechanisms capable of producing precisely controlled, substantially linear, single degree of freedom travel. It will be understood that the disclosed inventive functionality and methodology is not limited to the disclosed preferred-for-simplicity apparatus only, but that any apparatus that fulfills the defined functionality as claimed is included within the scope of the present disclosure. In addition, reduced functionalities, e.g. translation normal to plane of SSM without roll mode GCM pivoting, and/or without metatarsal articulation, are included within the scope of the present disclosure to the extent not already represented by specific prior art structures, e.g. Rennex.
Increased performance, i.e. action even more like that of an unbounded trampoline, involves GCM travel increase to avoid, to the extent possible, increased peak compression loads on the leg structures and/or to increase the elevation of the user's center of gravity for increase in “airtime” and potential stride length. In case of these extended travel GCMs, a point is reached where the previously-disclosed direction of extension travel, substantially normal to the SSM, becomes so awkward because of the effect of ankle articulation on fore-aft location of the GCM, that it becomes disadvantaged in comparison with parallel to shin extension travel that still provides for the GCM pitching mode parallelism to SSM as is clearly needed for control and peak performance.
Such inventive extended travel Full Suspension Footwear functionality (i.e. having parallel-to-shin extension travel with resilient urging, concurrent with GCM parallelism to SSM), may be achieved by numerous structural embodiments having, in common, A.) the previously-disclosed anti-rotation LBMA linear extension apparatus fixedly associated with (lower leg and SSM-stabilized) SBM, and B.) the previously-disclosed ankle joint roll mode stability in conjunction with SSM pitching mode mobility, via TAPA substantially coincident with that of the ankle joint. Four preferred embodiments will be briefly described, but it will be understood that the disclosed inventive functionality and methodology is not limited to the disclosed apparatus only, but that any apparatus which fulfills the defined functionality as claimed is included within the scope of the present disclosure.
These four principally-preferred arrangements for achieving the inventive extended travel functionality are briefly described and disclosed as follows:
(1) LBMA-guided extension member-mounted GCM with conjugate four-bar linkages (CFBLs) for resilient urging and pitching mode parallelism control;
(2) LBMA-guided extension member-mounted GCM with triple CFBLs for longitudinally compact resilient urging and pitching mode parallelism control;
(3) Conjugate CFBLs for LBMA extension functionality, with parallel (CFBL-based) pitching mode parallelism control; and
(4) LBMA-guided extension member-mounted GCM with conjugate reel springs having rocker pulley member motion transfer for resilient urging and pitching mode parallelism control;
all of which preferably utilize elastomeric torsion springs, but whose resilient urging characteristics may alternatively be provided by, or supplemented by, other springs known in the art including gas compression springs.
Also herein disclosed are transitional apparatus and method, having GCM extension directions between those of the above-disclosed moderate travel and extended travel embodiments, namely where GCM extension directions are continuously variable with ankle articulation, but at lesser angular amplitudes than those of the foot and SSM with respect to the shin. These continuously-variable directions are essentially “weighted averages”9 of previously-disclosed travel directions: A) normal to plane of SSM, which direction depends upon ankle articulation attitude with respect to shin, and B) parallel to shin The transitional extension directions apparatus and method are not preferred because of the additional complexity involved in their execution, but are disclosed for the purpose of demonstrating the uninterrupted continuity of relationship between the distinct functionalities defined for the preferred, for their relatively simpler architectures, moderate and extended travel embodiments. 9 With weighting being predetermined by structural proportions.
A preferred embodiment for this non-preferred transitional extension direction functionality utilizes an extension travel direction-defining link (or “ETDDL”) between bearing members having lateral pivot axes that are fixedly associated with, respectively, the SBM and the SSM. The lower SSM-mounted pivot axis of the ETDDL is located below the SSM's TAPA such that the pitching mode angular attitude of the ETDDL changes in response to ankle articulation, in the same rotational direction but with lesser angular magnitude.
Means are required for dealing with the geometric distance variations inherent in this “triangle” of pivot axes, as the angular relationship between its two shorter sides varies: preferred among the numerous possible alternatives is the employment of a short longitudinal anchor link (which adds an additional preferably rigidly transverse pivot axis with associated bearing members) between the SSM's below-TAPA pivot axis bearing members and the bottom of the ETDDL. This location, with anchor link angular orientation preferably perpendicular to the ETDDL when the plane of the SSM is perpendicular to the shin, minimizes the magnitudes of pitching mode moments about the TAPA which are applied to the SSM by compressive resilient extension member loading when the ETDDL departs from parallelism to the shin.
The extent to which the ETDDL mimics the behavior of either of the defined preferred inventive functionalities (moderate travel and extended travel embodiments) is dependent upon the proximity of ETDDL pivots to the TAPA, and can be varied between zero and 100% of either by this relative location. Whereas a weighted average of the two distinct extension directions inventively defined as preferred embodiments is produced by the lower ETDDL pivot of the as-defined transitional extension directions apparatus being a distance below the TAPA, moderate travel embodiment functionality is 100% replicated when the upper ETDDL pivot is coincident with, or zero elevation above, the TAPA, and extended travel embodiment functionality is 100% replicated when the lower ETDDL pivot is coincident with, or zero elevation below, the TAPA. Enforced division into two differing species is therefore considered inappropriate for preferred inventive functionalities that can be replicated by a single embodiment by the selection of a single parameter, namely ETDDL elevation relative to TAPA.
Now turning to the first of four principally-preferred extended travel embodiments, namely LBMA-guided extension member-mounted GCM with CFBLs for resilient urging and pitching mode parallelism control: adjacent or overlapping FBLs which share a common, or conjoining, link are known for the motion control characteristic of motion or attitude transference between non-adjacent opposing links. In the special case of parallelogram-type linkages operating in parallel or coincident planes, this transference maintains parallelism between opposite links of the same parallelogram. That is, when a FBL such as has been defined earlier, having substantially vertical links connected in substantially parallelogram array by substantially longitudinal links, the vertical10 links are maintained parallel to one another at all longitudinal link orientations. 10 For brevity of further discussion with respect to link orientation and identification within a substantially parallelogram four-bar linkage array, the term “vertical” will be substituted for, and taken to mean, “substantially vertical” by way of identifying links in said array, and the term “longitudinal” will be substituted for, and taken to mean, “substantially longitudinal”. Further, “parallelogram” and “parallelism” will mean “substantially parallelogram” and substantial parallelism”, etc. respectively: certain design objectives may favor the other than exactly 1:1 ratio angular transferences of unequal link configurations, as discussed previously.
Conjoined parallelogram FBLs, which share a common vertical link between them, can under appropriate conditions maintain parallelism between vertical terminal links that translate with respect to one another over a relatively wide range of distance from one another. This functionality, and the stiffness with which such a CFBL can readily relate migrating terminal links, is appropriate for maintaining parallelism of GCM with SSM over a wide range of extension travel. These appropriate conditions include having conjoining link pivot axis spacings of the individual FBLs' longitudinal links arrayed with substantially coincident midpoints to avoid imposing longitudinal translation upon terminal link rotation. This midpoint coincidence happens naturally when the opposing adjacent links of the separate FBLs share common pivot axes as is inherent to the employment of elastomeric torsion spring pivots for contribution to resilient urging. Attaching the vertical terminal links to SSM and GCM respectively, or integrating them into either, thus provides for the requisite pitching mode parallelism control between SSM and GCM as the GCM translates away from the SSM. Such a linkage arrangement for controlling angular attitude or parallelism between pivoting members which are free to translate towards and away from one another will be hereafter alternately termed a “Conjoined Four-Bar Linkage”, or “CFBL”. The CFBL structure provides opportunity for integration of resilient urging, preferably by incorporation of elastomeric torsion springs to resist collapsing of the linkage from an expanded free-state configuration.
The dual array CFBL just described is spatially stable, with the “flown” conjoining link being located without degree of freedom by its fixed length longitudinal links, which are in turn located by the LBMA-related SSM and GCM which comprise the CFBL's vertical terminal links.
A mobile extension member whose motion is LBMA-constrained to anti-rotating linear motion (or substantially linear, in case of advantage by means of slightly arcuate motion), carries its own transverse axis pivot bearing at its lower end, which in turn mounts a GCM assembly that, by pivoting on the extension member lower bearing, is able to follow the motions of, by remaining in substantially parallel relationship to, the SSM as it pivots with ankle articulation.
A preferred embodiment of the anti-rotational LBMA concept for the extended travel embodiment is a preferably extruded tube extension member having football-shaped cross section that transitions smoothly between opposing square corners which are preferably captured by two layers of low inertia, compliant-surfaced rollers comprising small anti friction bearings, each layer comprising a four-roller array that, by engaging the extension member in the vicinity of its opposing square corners with pure rolling contact (i.e. wherein the roller's axis of rotation is parallel to the engaged surface of the extension member and normal to its travel direction), provides strong anti-rotation rigidity concurrent with highly rigid, quiet, minimal friction translational motion in the parallel-to-shin direction by virtue of rigid connection of the two roller array layers to the SBM, the lower array layer as close as practicable to the SSM TAPA bearing in order to provide, in turn, as close as possible support to the GCM's pivot bearing, for reasons of structural rigidity and stress control.
The GCM of extended travel embodiment Full Suspension Footwear is resiliently urged downwardly away from the SSM in a direction substantially parallel to the shin, while being constrained to pitching mode parallelism to the SSM, in order to provide the balance control and performance benefits of ankle joint mobility without overpowering the ankle joint by adverse lateral roll moments from the increased (compared with lesser travels) GCM displacements with respect to SSM, as would be risked by extending the travel of the GCM in a direction normal to the SSM to an excessive amount. This freedom from ankle moment loading, at a cost of the architectural complexity of the extended travel SSM embodiment, is preferably used for travels which are greater than one third the length of the wearer's foot.
The second principally-preferred extended travel embodiment, LBMA-guided extension member-mounted GCM with triple CFBLs for longitudinally compact resilient urging and pitching mode parallelism control, shares the preferred LBMA extension member concept with the first embodiment described immediately above. Its parallelism control between SSM and GCM is also similar, except that in place of the above dual array CFBL, a more longitudinally compact “Z-like” triple array with angular symmetry of longitudinal links, with respect to extension travel direction, is substituted. The triple array of three conjoined FBLs includes two conjoining links to impose angular orientation control between terminal links. The middle of the three FBLs is preferably nearly twice as long longitudinally as the preferably similar outermost FBLs, such that the terminal links overlap at the center of longitudinal length when the array is vertically most compact. The middle FBL, when located only by the conjoining links of adjacent FBLs, is spatially unstable, not being of determined “flown” location as was the case of the conjoined dual FBL array, so for spatial stability of the entire array needs longitudinal location constraint. This longitudinal location constraint is preferably applied to the middle FBL, at the midpoint of a line between midpoints of the two conjoining links' pivot axis spacings, by means of an apparatus such as a pivotable “slider” bearing in substantially shin direction translational communication with a structure which can provide longitudinal location stability, the extension member for example. This longitudinal constraint needs to enable pivoting or rotation in order to accommodate the angular attitude changes of the middle FBL's longitudinal links during vertical or shin-wise expansion and contraction of the Z-like triple CFBL array. It needs to substantially translate in shin direction in order to accommodate the vertical or shin direction location changes of these links' midpoint that occur with extension member and GCM travel with respect to SSM. As in the case of the first principally-preferred extended travel embodiment, the vertical terminal links of the CFBL's “outermost” FBLs are located by their attachment to, or integration with, the LBMA-related SSM and GCM.
The third principally-preferred extended travel embodiment comprises conjugate CFBLs for LBMA extension functionality, with parallel (CFBL-based) pitching mode parallelism control.
A conjoined pair of FBLs of similar proportions can maintain co-linearity of terminal link relative motion at all separation distances, thus providing the longitudinal stability needed for anti-friction LBMA functionality, if conjugate motion is maintained between either pair of angularly opposed longitudinal links extending from separate conjoining link pivot axes, (hereafter “AOLLs”), the conjugacy being with respect to the plane of the pivot axes as if these angularly opposed separately pivoted links were “geared together” for mirrored angularity with respect to the plane of their pivots. The conjugacy constraint may indeed be imposed by means of gearing, or by alternative means of simulating non-slip rolling contact such as flexible linearly stiff tensile members such as cables or ribbons (hereafter “cables”) connecting features of substantially constant radii (hereafter “FOSCR”) which are fixedly associated with the AOLLs, respectively, the cables crossing one another at the plane of pivot axes from wrapping around one of the FOSCR to wrapping around the other, in non-slip tensile fashion. Alternate means of imposing the conjugacy of CFBL AOLLs as needed for LBMA functionality include, for limited angular travel situations, at least one longitudinally rigid conjugacy link connecting bearing members having pivot axes (which are parallel to AOLL pivot axes) which are anchored in opposing AOLL members, simulating the functionality of crossing cables with a kinematically similar linkage.
Since the conjugacy constraint stabilizes the CFBLs longitudinally, the LBMA-simulating co-linearity of terminal link relative motion may be obtained with either conjoined dual FBLs or conjoined triple FBLs. Even higher order CFBLs theoretically provide the same linear motion control if constrained to conjugacy between AOLLs, but the real-world rigidity of the co-linearity control is subject to the effective rigidities of both pivot bearing members and links, so degraded stability can be expected from increasing orders. An LBMA functionality-providing conjugate CFBL will hereafter be abbreviated as “CCFBL”, whether it is of dual, triple, or higher order CFBL construction.
In this CCFBL as LMBA apparatus, GCM parallelism to SSM must be controlled by means other than the LBMA-simulating CCFBL itself, whose terminal links are substantially constrained from allowing either longitudinal translation or pitching mode rotation. The preferred-for-simplicity parallelism control means is a parallelism control CFBL that parallels the LBMA-simulating CCFBL's longitudinal links, and adopts either the upper or lower chain of longitudinal links of the parallel CCFBL's array as sufficing to comprising “half” of the longitudinal links required by the parallelism-controlling CFBL, thus sharing vertical conjoining control link pivot axes with them, wherein the vertical conjoining control links operate independently, angular attitude-wise, of the CCFBL's vertical conjoining links except for the sharing of common pivot locations.
The fourth and last-defined principally-preferred extended travel Full Suspension Footwear embodiment comprises an LBMA-guided extension member which mounts the GCM via transverse pivot axis bearing members as defined previously, with both GCM pitching mode parallelism control and resilient urging with respect to SSM provided by a conjugate-reel springs-with-rocker-pulley member (or “CR/RPM”) motion transfer apparatus, including flexible tensile members, or cables, connecting the reel springs to the rocker pulley member, and either cables or links connecting the rocker pulley member to the GCM.
This CR/RPM motion transfer apparatus is defined as an arrangement of:
Paired and conjugately-coupled (or “geared together”) torsionally urged pullies (or “reel springs”) having respective pivot bearings that are connected structurally to the SSM, so as to maintain pitching mode congruency with it,
Two linearly stiff flexible tensile members (or “reel spring cables”) that are wrapped in non-slip fashion under each reel spring respectively to depart tangentially upwards, toward fixed or non-slip tensile association with;
A rocker arm, or at least one pulley, or a structure that combines both functionalities (hereafter “rocker pulley member” or “RPM”), that is pivotably (i.e. rotationally) mounted, via bearing members establishing a preferably transverse pivot axis, adjacent the upper end of the extension member in fixed center distance relationship to the GCM pivot bearing members below; and
two cables or linkage members (hereafter “GCM control links”) extending from the rocker pulley member (RPM) to appropriately separated attachment locations on the GCM.
The coupled reel springs maintain length equality between the reel spring cables that are played out, under resilient tension from the reel springs' restoring torques, upwardly to connect to the RPM at the top of the extension member. Non-slip connectivity of these reel spring cables to longitudinally opposing ends of the RPM, from which also emanate the substantially fixed-length GCM control links, assures that the pitching mode attitude and motion imparted to the SSM by the foot are transferred by the coupled reel springs and the reel spring cables to the RPM, and by the GCM control links to the GCM, so as to maintain parallelism between it and the SSM at all resilient extensibilities of the extension member and GCM with respect to the SSM.
The reel springs of this embodiment are preferably comprised of elastomeric torsion springs, for the mass and energy storage advantages cited previously. The large angular windup capacity required of the reel springs suggests that they be preferably of uniform torsional shear stress configuration, with axial elastomer section widths narrowing inversely with the square of radius as is known in the art. The relatively “tall”, radially, elastomer section of such a high windup configuration lacks the radial load carrying capacity of radially compact section bushings such as those preferred for previously-defined FBLs, so must, in order to provide pulley functionally for reel spring cable payout location stability, either be of multiple interleaf construction, for dimensional stability under tangential cable loads, or else have pulley structures “in parallel”, i.e. to allow rotation via single degree-of-freedom bearing means, while providing radial and lateral stiffness to assure location stability of the rim section as required by defined functionality. This defined functionality, in addition to reel spring cable payout location stability, includes the gearing, or coupling, together of the two reel springs in a tangency or closest proximity area such that they are substantially prevented from slippage or transmission error relative to each other so as to assure mirrored rotation.
The conjugate coupling functionality is preferably provided by crossed reel spring cables which are secured and wrapped in non-slip fashion around both pullies in both directions to constrain circumferential travel of one to the other in both directions, for the “toothless gear” functionality of non-slip rolling contact between two cylinders or discs. Outside surfaces of the reel springs preferably touch in rolling contact to assist in carrying the inwardly radial loading of the crossed reel spring cables. The outside surface of each reel spring is preferably cushioned, for silence of contact and rotation, by an elastomeric cushion ring of rounded conic outer “diameter”, so as to offer slightly crowned rolling contact area with its mating reel spring that will assure sufficient durability under service. The conic outer surface maximizes rolling contact area despite the axes and the planes of the reel springs being preferably skewed such that the planes of the reel springs are folded with respect to one another about a substantially vertical intersection line for packaging space conservation and reel spring cable payout location optimization.
This preferred crossed cables configuration for the conjugate coupling of the reel springs in their tangency/proximity area may alternatively be either combined with, or replaced by, meshing gear teeth at penalty to operational quietness. The conjugacy of the reel springs' outer rim members combines with their radial stiffnesses to cause the reel spring cables paid out to the RPM to reflect the pitching mode attitude of their (the reel springs) central axis bearing members, which are preferably attached directly to the SSM.
At all extents of cable payout, the effective lengths of the reel spring cables differ by the same amount as they would if reel spring rotation were to be prohibited, thereby accurately conveying SSM pitching mode attitude and motion into RPM attitude and motion. GCM attitude and motion are maintained to staying parallel with SSM as conveyed by the GCM control links from the RPM. These GCM control links either comprise CFBLs, with parallelogram proportionalities between pivots, or else act like pullies, with constant radii at payout points and cables engaging (or wrapping around) the constant radii. The pulley type payout region option offers advantages of reduced mass and inertia in that the RPM can substitute angular travel for radius, for structural compactness advantage, in the case where the GCM control links comprise cables. A corollary advantage of this approach is that the inward slanting of the reel spring and GCM control cables towards the RPM moves their payout regions upward in the case of the GCM, increasing ground clearance in the real-world conditions of heel strike and toe-off angularity of GCM to treading surface. It is necessary, for maintenance of FBL-like geometry as pitching mode attitude of the SSM is varied, that the engagement radii of the RPM about its pivot axis reflect the proportionality of reel spring payout radii about the TAPA, and that GCM control link engagement radii similarly reflect this proportionality, thus also reflecting the mechanical advantages (or leverages) engineered into the foot itself.
Examples of inventive Full Suspension Footwear elements are shown in the drawings; it is to be understood that not all useful permutations of these elements are illustrated, and that these drawings are merely illustrative of concept, not to be interpreted as limiting in scope. Moreover, while various illustrations are shown, it will be understood that the various components of the disclosed motion control apparatus can be interchanged or combined as desired to suit the specifics of an application or situation.
In schematic illustration
In schematic illustration
In
The GCM 196 features the ATPM 200 resiliently urged to parallelism with the majority lower surface of the GCM 196 by the ETS pivot 201, having piano hinge-like construction about a common axle to halve the torsional displacement (and thus requisite elastomeric section height) of its individual, adjacently interspersed, torsion bushings. These individual torsion bushings are preferably torsionally balanced, having equal lateral direction length sums in fixed associativity with the ATPM 200 and the GCM 196 respectively, such that their common axle is rotated one-half the total displacement angle of the ATPM 200 with respect to the GCM 196, for uniform torsional shear stress distribution among the hinge bushings.
The SSM 225 supports the user's foot and includes known structures (not detailed) or for its firm attachment to same. Alternatively, the SSM 225 includes known structures (not shown) for attaching to a separate shoe member that securely encloses the user's foot. Sidewall upward extensions, preferably on both sides of the foot, from the plane of the SSM region, mount the upper longitudinal link pivot 235 in fixed relationship to the lower link pivot 232, which is preferably integrated into the SSM's forward portion. The use of a full width ETS pivot bushing is illustrated, with its practical requirement of pivot axis location below the SSM, but it is understood that other types of link pivot bearings at other locations may be substituted within the scope of the invention, a sealed single row ball bearing elevated to being adjacent the small toe metatarsal, for example.
The GCM 226, which includes the ATPM 230 attachment via the common axle piano hinge 231 similar to that of
The hub 251 and the inertia member 252 of
It is also known best practice to incorporate generous transition radii at section free ends, to gradually reduce bond line shear stresses instead of incurring stress concentrations of more abrupt transitions. The section end corner radii 261, 262, 264, and 265 exemplify this prior art practice, with further benefit from the section end fillet radius 253 which the mold bonding process facilitates.
The general slope of the section end boundary radius 287 between the bondline stress relieving fillet 295 and the transition region boundary radius 274 is represented by the construction line 288. Since this line, and the horizontal (parallel to centerline) construction line 294, which reflects the preferred section end boundary 282 of the disc region just above the tangency points of the transition region radii, can be said to represent best practice boundary configurations at both ends, respectively, of the transition region, preferred section end boundary configurations for partial usage of transition region geometry by ETS elastomeric sections may be found by interpolation between them, by the device of using their intersection point or the vertex 289 for construction of the preferred partial usage ETS section end configurations. Accordingly, an ETS section configured by means of prior art transition region radii for packaging advantage that needs to utilize only that volume represented by the boundary line 299 will preferably use the construction line 291, from the construction vertex 289, to define the general slope of the section ending boundary line 299. The bondline fillet radii 297 and 298 may be of differing size in cases of being near the cylindrical, uniform numerical stress boundary condition, in light of the intersection angles therein comprised, but will preferably approach equality as the symmetry of the disc region is neared. The disc region end boundary 282, for example, preferably uses equal sized bondline transition fillets 296 because of the symmetry with which the purely axial construction line 294 intersects the disc section boundary lines 277 and 278.
In
The SSM 425 also preferably comprises air guide passages 433 that extend between and communicate with openings at the front and rear of the SSM to promote ventilation. The upper walls of the air guide passages 433 preferably form the plane of the SSM 425, and are preferably perforated with breathing orifices 428 which enable heat and moisture to be transferred from the sole of the user's foot according to a preferred embodiment of the invention.
Lifting of the ATPM 452 thus pulls and causes translation of the cable 464 within the sheath 461, concurrently lifting the AMTSM 453.
The motion control apparatus of this Figure includes FBL pivots 483 and 484 in substantially vertical array, fixedly associated to an SSM 485 and forming a first terminal link (485); FBL pivots 493 and 494 in substantially vertical array and with pivot spacing substantially identical to that of the pivots 483 and 484 of the first terminal link, fixedly associated to a GCM 486 and forming a second terminal link (486); a conjoining link 489 with pivots 486 and 487 also in substantially vertical array and with pivot spacing substantially identical to that of the pivots 483 and 484 of the first terminal link (485), substantially parallel upper longitudinal links 481 and 482 extending between the pivots of the first terminal link (485) and the conjoining link 489; substantially parallel lower longitudinal links 491 and 492 extending between the pivots of the conjoining link 489 and the second terminal link (486); and a conjugacy link 490 connecting pivots of AOLLs 481 and 492. The conjugacy link 490 assures mirrored angularity of the AOLLs with respect to the plane of their pivot axes as discussed previously, limiting the relative motion of the first and second terminal links (485) and (486), and the SSM 485 and the GCM 486 that comprise them, to linear translation, as is known. Resilient urging is preferably provided by ETS spring loading between adjacent links of a common conjoining link pivot, as illustrated in
The curtain member 495 is provided to prevent foreign objects from entering the “mastication space” between the SSM 485 and the GCM 486, but is preferably also utilized as a travel stop for preloading of resilient urging. The GCM 486 preferably comprises engineered elasticity of the region forward of that corresponding to the metatarsals of the user's foot so that leaf spring action with resilient urging back to free state flatness of the GCM 486 provides ATPM functionality.
The disclosed parallelism of the GCM 506 with the SSM 505 is provided by a previously disclosed CFBL motion control apparatus. The SSM 505 comprises pivots 515 and 516 in substantially vertical array, forming a first terminal link (505); the GCM 506 comprises pivots 519 and 520, in substantially vertical array and with substantially identical spacing as that of first terminal link (505), forming a second terminal link (506); a substantially vertical conjoining link 510 comprises pivots 517 and 518 in substantially identical spacing as that of first and second terminal links (505) and (506); substantially parallel upper longitudinal links 511 and 513 extend between the pivots of the first terminal link (505) and the conjoining link 510; substantially parallel lower longitudinal links 512 and 514 extend between the pivots of the conjoining link 510 and the second terminal link (506). The adjacent angularly opposed links comprising each individual conjoining link pivot location are preferably resiliently urged torsionally by preferably ETS pivots as illustrated in
The disclosed parallelism of the GCM 536 with the SSM 535 is provided by a previously disclosed triple CFBL motion control apparatus. The SSM 535 comprises pivots 545 and 546 in substantially vertical array, forming a first terminal link (535); the GCM 536 comprises pivots 554 and 555, in substantially vertical array and with substantially identical spacing as that of first terminal link (535), forming a second terminal link (536); a substantially vertical first conjoining link 540 comprises pivots 547 and 548 in substantially identical spacing as that of first and second terminal links (535) and (536), and a substantially vertical second conjoining link 551 comprises pivots 549 and 550 in substantially identical spacing as the others; substantially parallel upper longitudinal links 541 and 543 extend between the pivots of the first terminal link (535) and the first conjoining link 540; substantially parallel lower longitudinal links 552 and 553 extend between the pivots of the second conjoining link 551 and the second terminal link (536). Extending between the pivots of the first and second conjoining links 540 and 551 are substantially parallel middle longitudinal links 542 and 544, one of which (the lower, 544 in this example) is constrained longitudinally by comprising a slider pivot 556 that, by means of a roller carriage 557 in substantially shin direction translational communication with the extension member 538, provides longitudinal location stability to the middle FBL while allowing its vertical motion with respect to the SSM pivot 533 that accompanies shin-wise translation of the GCM 536. Resilient urging is preferably by means of ETS torsion distributed among the four conjoining link pivots as detailed previously, but may alternatively be any known means of resilient urging.
The SBM 581, which is fixedly associated with the shin by a snugging strap 582, etc., comprises pivots 587 and 588 in substantially vertical array, forming a first terminal link (581); the extension member link 609 comprises pivots 590 and 591, in substantially vertical array and with substantially identical spacing as that of first terminal link (581), forming a second terminal link (609); a substantially vertical conjoining link 594 comprises pivots 592 and 593 with substantially identical spacing as that of first and second terminal links (581) and (609); substantially parallel upper longitudinal links 596 and 597 extend between the pivots of the first terminal link (581) and the conjoining link 594; substantially parallel lower longitudinal links 598 and 599 extend between the pivots of the conjoining link 594 and the second terminal link (609). The upper longitudinal link 596 and the lower longitudinal link are AOLLs that if constrained to conjugacy with respect to the plane of their pivots 592 and 593 constrain the two FBLs to mirrored motion, precluding independence of angularity of the separate FBLs with respect to the conjoining link. This mirrored motion constrains the upper and lower terminal links (581) and (609) to colinear relative motion, mimicking the action of linear bearing member assemblies. The upper FBL longitudinal link 597 and the lower FBL longitudinal link 598 also are AOLLs that could alternatively, or additionally, be constrained to conjugacy in order to produce LBMA functionality. The prescribed conjugacy is, for expediency in this illustration, provided by meshing gear teeth 607 and 608, formed in upper and lower AOLLs 596 and 599, respectively. Lower cost conjugacy controls such as crossed tensile members (ribbons or cables) or a conjugacy link may be preferable in actual practice.
The SSM pivots in pitching mode on TAPA bearing 583, while the GCM 586 pivots in pitching mode on transverse axis pivot bearing 589. The selection of a location, for conjoining control link pivot bearing 595, on the conjoining link 594 which corresponds to those of the TAPA 583 and transverse axis pivot bearing 589 in relation to their terminal link pivots provides a fixed “phantom link” length relationship that can serve as half of the parallelism control CFBL structure. The GCM 586 thus is angularly controlled, with respect to its transverse axis pivot bearing 589, by a single lower longitudinal control link 605 connecting a GCM control pivot 606 to a conjoining control link pivot 604, the conjoining link's angular attitude in turn controlled by an upper longitudinal control link 600 connecting a conjoining control link pivot 602 with an SSM control pivot 601.
The GCM 586 in this illustration preferably comprises an engineered elasticity forward portion that provides ATPM flexure with resilient urging by leaf spring action.
As in
The CRs 632 and 633, not detailed, each comprise the functionally parallel structures of; 1) a preferably ETS torsional urging apparatus fixedly associated with the SSM 625, and with respect to this fixedness resiliently urging rotation of the rim of; 2) a pulley-like structural support apparatus which permits rotation of its FOSCR rim while locating it in spatially stable fashion by a rotary bearing member assembly with substantially horizontal pivot axis orientation also of structural associativity with the SSM 625, such that the two CRs spatially follow pitching mode motion of the SSM while their rims rotate in mirrored conjugacy with resilient urging, in response to extension member travel. The configuration of the high windup ETS for reel spring resilient urging is preferably the intersection of prior art transition region torque transfer members with prior art uniform numerical stress cylindrical ETS elastomer end contours as illustrated in
A reel spring cable 634 in non-slip associativity with a groove in the rim of CR 633 passes over the top of CR 633 to cross over to a similar groove in the rim of CR 632, the bottom of which reel spring cable 634 then passes under on its way to tangent payout in the direction of the small radius rearward facing groove of the RPM with which it is fixedly associated in non-slip fashion. A second reel spring cable 635 passes over the top of CR 632 to cross over to a similar groove in the rim of CR 633, the bottom of which reel spring cable 634 then passes under on its way to tangent payout in the direction of the large radius forward facing groove of the RPM with which it is fixedly associated in non-slip fashion. Both reel spring cable 634 and reel spring cable 635 are resiliently urged downwardly by the rotational resilient urging of CRs 632 and 633 which try to reel them in, in equal linear amounts at any given pitching mode attitude of the SSM 625. This resilient downward urging acts, through the RPM 631 and its pivot bearing 630, to force the GCM 626 downwardly away from the SSM 625 by means of the GCM 626's attachment, through transverse axis pivot bearing 629, to the extension member 628.
A GCM control link cable 636, extends between a FOSCR detail 638 of the GCM 626 and the small radius rearward facing groove of the RPM with which it is fixedly associated in non-slip fashion, and a GCM control link cable 637 extends between a FOSCR detail 639 of the GCM 626 and the large radius forward facing groove of the RPM with which it is fixedly associated in non-slip fashion. These GCM control link cables reflect to the GCM 626 the angular orientation of the SSM 625 as transmitted by the reel spring cables 634 and 635 to the RPM. The RPM is preferably of smaller proportions than those of the SSM 625 and the GCM 626: its angular travel will thus be greater than those of the SSM and the GCM.
The GCM 676 is in this rollerblade apparatus comprises at least two wheels 686 rotatingly associated with the frame of GCM 676 with transverse rotational axes. An optional wheeled ATPM 682, pivotingly associated with the GCM 676 by a pivot 681 is preferably constrained to substantially angular parallelism between a line tangent to the bottom of its at least one wheel and the bottom of the forwardmost wheel of the GCM 676, and the plane of an AMTSM by, in this example, a flexible sheath type control cable apparatus.
Alternative “all terrain” rollerblade embodiments of Full Suspension Footwear preferably utilize only two large diameter wheels of substantial tread area located in front of and behind the user's foot for minimization of nominal foot elevation above the treading surface. Such all terrain embodiments are preferably of SBM-stabilized extended travel architecture and travel direction, but both inventive preferred embodiments of travel magnitude and associated travel direction are herein disclosed in conjunction with wheeled GCMs.
GCM: ground contact member
SSM: shoe sole member
shin: lower leg structures, also a descriptive substitute for a line between the knee and ankle join and thus the laterally nominal direction of force transfer, or load centerline
TAPA: transverse ankle pivot axis
SBM: shin brace member
ATPM: articulating toe pressure member (preferred component of GCM)
AMTSM: angularly mobile toe support member (preferred component of SSM)
FBL: four-bar linkage
LBMA: linear bearing member assembly
CFBL: conjoined four-bar linkage
CCFBL: conjugate conjoined four-bar linkage
ETDDL: extension travel direction-defining link
FOSCR: features of substantially constant radii cables: linearly stiff flexible tensile members; ribbons
AOLLs: angularly opposed longitudinal links
CR/RPM: conjugate reel springs with rocker pulley member.
This application is a divisional application of U.S. patent application Ser. No. 11/148,744, filed on Jun. 7, 2005 entitled “Full Suspension Footwear” which claims priority from U.S. Provisional Patent Application Ser. No. 60/577,632, filed Jun. 7, 2004, and entitled “Springy Sport Shoes” and U.S. Provisional Patent Application Ser. No. 60/655,925, filed Feb. 24, 2005, and also entitled “Springy Sport Shoes”.
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| Number | Date | Country | |
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| 20100281710 A1 | Nov 2010 | US |
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| Number | Date | Country | |
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| Parent | 11148744 | Jun 2005 | US |
| Child | 12842460 | US |
