APPARATUS FOR ENHANCED HUMAN-POWERED LOCOMOTION

Abstract

A foot or shoe-borne apparatus comprises a spacer and spring assembly that can be oriented in two orientations. In the first orientation, the assembly is under the sole of a user's foot or shoe such that the assembly acts against the ground for enhanced locomotion for that foot or shoe. In the second orientation, the assembly is positioned away from the sole of the foot or shoe, thereby enabling ordinary use of that foot or shoe.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of and priority to Canadian Patent Application No. 2,812,815 filed Apr. 9, 2013 the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

The invention relates to apparatus for human-powered locomotion. In particular the apparatus is a foot-borne device which can be used for enhanced skateboarding, walking, running, jumping and other human foot movement.

BACKGROUND OF THE INVENTION

There are few effective foot-borne devices for use by users which can assist in movement.

There is a need to provide

BRIEF SUMMARY OF THE INVENTION

The invention provides a foot-borne or shoe-borne spacer and spring assembly that can be quickly and easily configured in one of two orientations: a first, so-called ‘down’ orientation in which the spacer and spring assembly engages the ground and enables spacer and spring-assisted locomotion, and a second, so-called ‘up’ orientation in which the spacer and spring assembly does not engage with the ground and which allows normal use of the foot and shoe as in ordinary, un-assisted locomotion, standing, or resting etc.

In what follows, the ground-engaging orientation of the spacer/spring assembly will be referred as the ‘down’ orientation. The ground non-engaging orientation will be referred as the ‘up’ orientation.

The invention enables spacer/spring-assisted, foot-based locomotion when the spacer/spring assembly is ‘down’ and also enables ordinary non-spacer/spring-assisted use of the foot and shoe when the spacer/spring assembly is ‘up.’ The invention furthermore allows for the easy and rapid reconfiguration of the spacer/spring assembly from ‘down’ to ‘up’ (and vice-versa) at the user's discretion. In other words, the user can easily and rapidly affect a change from one orientation to the other.

Taking an example wherein the user is skateboarding, a device of the invention with spacer/spring assembly ‘down’ enables a spacer/spring-assisted power-stroke that propels the user and skateboard forward. When the user places the spacer/spring in the ‘up’ position, the invention allows normal functioning of the user's foot and shoe, including, in the present example, normal skateboarding, standing on the skateboard during gliding, as well as walking or any other activity off the skateboard.

Depending on the specifics of the user's body ergonomics, the invention in the ‘down’ position may assist the user in any or all of the following ways: increasing efficiency of the user's motion, extending the reach of the user's power-stroke, minimizing vertical displacements of the user's center-of-mass, performing energy recovery to the user's foot during the end of the power-stroke, improving ergonomics or comfort, and absorbing shock that would otherwise occur between the user's foot and the ground.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a first embodiment of the invention, showing the spacer/spring assembly in the ‘down’ orientation.

FIG. 2 is a side view of a first embodiment of the invention, showing the spacer/spring assembly in the ‘up’ orientation.

FIG. 3 is a side view of a second embodiment of the invention, showing a hinged, sheathed pogo type spacer/spring assembly, in the ‘down’ orientation (solid lines) and the ‘up’ orientation (dashed lines);

FIGS. 4a and 4b illustrate detailed views of the spacer/spring assembly of the second embodiment of the invention, showing the spacer/spring assembly in the ‘down’ orientation and locked (4a) as well as the same spacer/spring assembly in the ‘up’ orientation (4b);

FIGS. 5a and 5b illustrate a third embodiment of the invention in which the ‘up’ and ‘down’ orientations are effected by a lever for manual rotation by the user.

FIGS. 6a, 6b, 6c and 6d illustrate a sample wireframe secondary spacer/spring that is appropriate for use in the first embodiment of FIGS. 1 and 2.

FIGS. 7a and 7b illustrate a fourth embodiment of the invention.

FIGS. 8a and 8b illustrate a fourth embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The apparatus of the present invention provides for a foot or shoe-borne spacer/spring that can be quickly and easily oriented in either of two distinct orientations, a ‘down’ orientation which allows the spacer/spring to engage with the ground, thus enabling spacer/spring-assisted locomotion, and an ‘up’ orientation in which the spacer/spring does not engage with the ground and thus allows normal use of the foot and shoe. These two orientations are referred to as the ‘down’ and ‘up’ orientations, respectively.

To describe the two orientations more precisely, consider that the ‘down’ orientation refers to the condition in which the spacer/spring assembly is positioned below the sole of the user's foot/shoe and is directed more or less perpendicularly to the sole of the user's foot/shoe. In this orientation the spacer/spring is able to engage with the ground when the user performs a power stroke, that is, when the sole of the user's foot/shoe exerts a force against the ground. In this orientation the spacer/spring assembly can act as a spacer that positions the user's foot in a posture advantageous for ergonomics. This can also create compression in the spacer/spring, thereby storing energy, which can be subsequently released at the end of the power stroke, that is, upon removal of the compressive force, thereby enhancing the efficiency and possibly the force of the power-stroke.

In the ‘up’ orientation, the spacer/spring assembly is positioned away from the bottom of the sole of the user's foot/shoe. The spacer/spring assembly is instead oriented above the foot/shoe or beside the foot/shoe. In the ‘up’ orientation the spacer/spring subsystem no longer engages with the ground during normal use of the foot/shoe and thus permits normal use of the foot/shoe, that is, non-spacer/spring-assisted use of the foot/shoe as in ordinary locomotion, resting, or standing, etc.

One advantage of the invention is that the apparatus can be construed to fit the user's existing shoe. A second advantage is that the user is able to easily and quickly change the orientation of the spacer/spring, in some cases, in the midst of physical activity. This is described below after first summarizing the distinct functional subsystems.

The invention in all its manifestations and embodiments includes three functionalities. Each functionality is usually, but not necessarily, embodied in its own mechanical subsystem: (S1) a spacer or spacer/spring; (PAL2) a pivot, actuator and lock, and (A3) an attachment to the user's foot/shoe and even the user's body.

(S1) Spacer/Spring Functionality

The spacer/spring functionality (S1) while in the ‘down’ position, enhances the power stroke of the user's locomotion. This is by way of the mediating influence of the spacer/spring when it is positioned between the shoe and the ground.

(PAL2) Pivot, Actuator, and Lock Functionality

The pivot of the PAL2 functionality represents a hinge or swiveling means that allows the spacer/spring to be oriented in either of the two possible orientations, ‘down’ or ‘up.’ The particular orientation at any given moment is chosen at the user's discretion, by way of an actuation means that also comprises the PAL2 functionality. Finally, the lock function of the PAL2 functionality refers to the means by which the spacer/spring, while in the ‘down’ position, is held firmly in position during the power-stroke.

The PAL2 subsystem, along with the other subsystems, must also perform an additional function, namely the function that ensures that the two configurations of the spacer/spring (‘down’ and ‘up’) represent mechanically quasi-stable configurations. In other words, the spacer/spring should rest in each orientation and should not spontaneously change orientation under the influence of weak, random forces such as those caused by inertia, wind, or inadvertent contact with the user's clothing or road debris etc. On the contrary, the spacer/spring's orientation should be changed only by way of an intentional, but simple, user-actuation as described herein.

The system should have minima in the mechanical self-energy function at both the ‘down’ and ‘up’ orientations. This can be realized by way of detents or ‘catches’ built into the S1 and PAL2 subsystems. These quasi-stable resting are distinct from the locked ‘down’ position mentioned previously. The latter ensures the spacer/spring remains firmly in the ‘down’ position during the power stroke. This is further elaborated in the descriptions below.

(A3) Attachment Functionality

The attachment functionality (A3) embodies the means by which the invention can be fastened to the user's body. Depending upon the particular embodiment, this can include the user's foot, ankle, shoe, leg, and hip.

The three subsystems are best understood by considering the drawings in light of the examples.

Example 1

FIGS. 1 and 2 show a first embodiment of the invention. FIG. 1 illustrates the ‘down’ position, in which the spacer/spring assembly S1 is positioned below the foot. FIG. 2 illustrates the ‘up’ position, showing the spacer/spring behind and above the heel area of the foot.

This embodiment of the invention illustrates an apparatus 5 comprising two parts: a first ‘primary’ spacer/spring 10, and a second, ‘secondary’ spacer/spring 11. The primary spacer/spring 10 is designed to simultaneously contact the ground and the sole of the user's shoe when in the ‘down’ position. The secondary spacer/spring 11 is designed to enable pivoting of spacer/spring 10 between ‘down’ and ‘up’ positions. The secondary spacer/spring 11 also possesses inherent spring-like properties in order to accommodate compression travel of the primary spacer/spring when under compression, such as from the weight of the foot. The secondary spacer/spring must also realize PAL2 functionality via its coupling to the hinge 20 as will be described below.

In this first embodiment, the primary spacer/spring 10 takes the form of a sphere or cylinder constructed of a robust material, preferably with inherent elastic properties. Appropriate materials include but are not restricted to metal or composite flat-form springs, coil compression springs, solid urethane foam or rubber, or hollow polymer balls or cylinders. Other materials having elastic properties are contemplated.

The secondary spacer/spring 11 is a stirrup-shaped or generally ‘U’-shaped wire-form constructed of materials commonly used for springs, such as ‘spring steel’ and the like.

The secondary spacer/spring 11 attaches to strap 30 via a hinge 20. Strap 30 can be worn by user on the foot or be attached to user's shoe. Alternatively, strap 30 may be an integral part of a shoe. Detents or grooves on the outer edges of hinge 20 can partially realize the PAL2 functionality of quasi-stable resting states for the ‘down’ and ‘up’ orientations. More precisely, the secondary spacer/spring 11 and the hinge 20 can be designed so that their mechanical coupling produces quasi-stable ‘down’ and ‘up’ configurations. The locking feature of PAL2 is realized by the shape of the secondary spring 11 which includes re-curve 12 and by the fact that the primary spacer/spring 10 contacts the sole of the user's foot/shoe, thus providing a locking force during the power stroke.

The attachment functionality A3 is realized by a strap subsystem that can straps onto user's foot or user's shoe by way of strap 30 and heel cup 31. Both strap 30 and heel cup 31 can have adjustment means to ensure snug fit and user comfort.

In this embodiment, strap 30 and heel cup 31 transcribe the outer perimeter of the foot/shoe. These may optionally incorporate reinforcement such as metallic bands for extra strength. Alternatively, the attachment functionality A3 can be built into a specially designed and customized shoe. This can be readily realized by gluing or permanently embedding or fastening pivot 20 into the shoe itself.

As illustrated in FIGS. 1 and 2, apparatus 5 allows the primary spacer/spring 10 to rotate around user's heel, thus enabling the two configurations. In the ‘down’ configuration the primary spacer/spring 10 mediates the user's power stroke against the ground. In the ‘up’ position the primary spacer/spring 10 is lifted away from the sole of the foot/shoe, thus allowing for more-or-less normal operation of the foot/shoe.

As indicated previously, the meta-stability and the locking aspects of the PAL2 functionality are realized by judicious design of the coupling between the primary spacer/spring 10 and the hinge 20. An alternative design comprises the secondary spacer/spring 11, constructed of a material such as spacer/spring steel and possessing some residual tension, that presses its lateral sections against the mating lateral surface of the coupling. Concurrently, hinge 20 is constructed with appropriate grooves that act as detents.

By proper design of all the mating surfaces between the secondary spacer/spring 11 and the hinge 20, apparatus 5 provides a meta-stable resting points for the spacer/spring while in the ‘down’ and ‘up’ positions.

The actuation means of this embodiment of the invention is realized by way of the shape of the S1 subsystem. Staring from the ‘down’ orientation, the user can achieve the ‘up’ configuration seen in FIG. 2 by lifting the foot/shoe off the ground and by applying a scraping motion of the user's foot/shoe relative to the ground in such a manner as to avoid to compression of primary spacer/spring 10 but instead achieving the swiveling of the spacers/springs 10, 11 into the ‘up’ configuration of FIG. 2.

Starting from the ‘up’ position the user can achieve the ‘down’ position by manually pushing the spacer/springs 10, 11 down or by performing a scraping motion of the heel against the shin of the opposite leg or against any other convenient surface.

The apparatus 5 allows the user to easily and conveniently set the spacer/springs 10, 11 into either ‘up’ or ‘down’ meta-stable positions. The user thus has freedom to freely transition the spacer/springs 10, 11 between its two orientations and thus deploy the spacer/springs 10, 11 during the power-stroke of spacer/spring-assisted locomotion, and to remove the spacer/springs 10, 11 from the bottom of the foot/shoe when ordinary use of the foot/shoe is desired.

As indicated previously, in this embodiment the locking functionality of the PAL2 sub-system is achieved by the re-curve 12 of the secondary spacer/spring 11. This can also be achieved by appropriate modifications to the coupling hinge 20. These features ensure that when the apparatus 5 is in the ‘down’ position, the system locks into position as long as a suitable compression force is maintained between the foot/shoe and the ground. When the compression force is removed, the system returns to the metastable ‘down’ position which is easily altered by the user as described above.

To illustrate an embodiment of the wire-frame secondary spring 11, supplementary FIGS. 6a, 6b, 6c and 6d are provided. FIG. 6a illustrates one embodiment of the wireframe as it appears when held approximately vertical, looking down. FIG. 6b illustrates one embodiment of the wireframe as it appears sitting on a bench with the curve oriented upwards. FIG. 6c) illustrates one embodiment of the wireframe as it appears in a perspective side view. FIG. 6d) illustrates a side view of one embodiment of the wireframe, showing an approximate 80 degree angle between the attachment portion and main portion. Other angles between portions of the wireframe are contemplated.

It is noted that that the specific features of the invention are in no way limiting of the invention and are merely examples of practical realizations of the invention. For example, it is not necessary for the pivot to be located behind the heel. Instead, other embodiments can be construed with the pivot located closer to the front of the foot. Similarly, other variants can be contrived that enable an ‘up’ position at the side of the shoe. The generality of the invention can be further illustrated by considering other embodiments of the invention as in the following examples.

Example 2

FIG. 3 illustrates a second embodiment of the present invention. In this embodiment, the apparatus 5′ comprises a compressive spacer/spring 10′ (shown in cutaway) that is housed inside a tube or sheath 11′. The spacer/spring 10′ is connected to a shaft or piston 12′ that is optionally terminated at its lowest end with a pad 13′ for contacting the ground.

The ‘down’ configuration is delineated by solid lines in FIG. 3. This is the default or resting configuration of the spacer/spring system in this embodiment of the invention. The ‘up’ configuration, delineated with dotted lines in FIG. 3 and is achieved by pivoting the spacer/spring assembly upward and backward, toward the heel of the shoe. This is enabled by the hinge 20′, which is built into the piston or shaft 12′ and which embodies the pivoting and locking means of the PAL2 functionality of the invention in this embodiment.

As in the previous embodiment of the invention, the attachment functionality A3 is accomplished by way of straps 30′, 31′, and 32′, which hold the sheath 11′ in place against the side of the shoe and the user's ankle.

In this embodiment, the locking means required by PAL2 functionality is automatically achieved when the spacer/spring assembly is compressed by the action of the user's foot. This is realized by ensuring that the hinge 20′ is situated near the lower portion of the shaft 12′ in such a way that even slight compression pushes the hinge 20′ into the sheath 11′ and prevents any rotation of the hinge, thereby preventing the spacer/spring subsystem from moving into the ‘up’ configuration. This is illustrated in FIGS. 4a and 4b, which show the ‘up’ and ‘down’ positions respectively, of the spacer/spring sub-system including the hinge 20′.

The meta-stability of the ‘up’ configuration is realized by the artifice of a friction-stop 34′ consisting of a knob, flexible hook, ridge, or mating depression on the strap that accepts the lower portion of the spacer/spring assembly shaft 12′ and/or the pad 13′ and thus maintains the lower portion of the spacer/spring assembly in the ‘up’ orientation during ordinary functioning of the shoe.

Actuation of the system is accomplished either manually or by scraping the side of the shoe against the ground. For example, the pad 13′ provides a convenient surface for the user to manually release the shaft 12′ from the ‘up’ position and to thus initiate the ‘down’ position as needed for a spacer/spring-assisted power stroke of the foot against the ground. Alternatively, the ‘up’ configuration can be achieved by the user removing pressure from the spacer/spring assembly by lifting the foot off the ground and by manually rotating the piston backward or by applying a diagonal downward and forward force, as in a scraping motion, that does not compress the spacer/spring but instead forces the shaft 12′ into the ‘up configuration.

To summarize, characteristic features of this second embodiment of the invention are: (a) the spacer/spring assembly 10, 11, positioned laterally on the shoe; (b) the spacer/spring assembly utilizes a piston-type action, and (c) the ‘up’ configuration is achieved by pivoting the spacer/spring assembly backward, toward the back of the shoe.

As discussed with the previous, first embodiment, the specific features of the second embodiment are in no way limiting of the invention and are examples of practical realizations of the more general, essential functionalities of the invention. For example, the ‘up’ and ‘down’ orientations of the second embodiment are achieved by hinge 20′. This is illustrative of the general principle and an alternate design could be arranged which does not use a hinge but instead wherein the spacer/spring is connected to a solid, non-hinged piston and the piston and sheath are so arranged at their upper ends so that when the spacer/spring is fully compressed, the piston protrudes through the top of the sheath where a latch would be implemented to maintain the spacer/spring compression and thus the ‘up’ configuration indefinitely.

The generality of the invention can be further illustrated by considering a third embodiment of the invention in the following.

Example 3

FIGS. 5a and 5b illustrate respectively, the ‘down’ and ‘up’ positions of a third embodiment of the present invention. This embodiment has some similarity with the second embodiment illustrated in FIGS. 3, 4a, and 4b because both embodiments incorporate a sheathed spacer/spring assembly.

In keeping with the numbering used in the previous, second embodiment, the apparatus of the third embodiment is numbered 5″ in FIGS. 5a and 5b. The spacer/spring 10″ is housed inside the sheath 11″.

This third embodiment of the invention differs from the second embodiment because the PAL2 functionality is realized by way of a handle 20″ which is contiguous to the piston or shaft 21″ and whose lower terminus has a contact 22″ that engages with the ground. By way of the handle 20″ the user can manually couple or decouple the shaft 21″ from the internal spacer/spring 11″. This is accomplished by providing the shaft 21″ with an internal shelf or notch, not illustrated in FIGS. 5a and 5b, which couple or decouple the shaft 21″ to the spacer/spring, depending on the angle of rotation.

As in the previous figures the attachment functionality A3 is realized by way of straps 30″ and 31″.

To summarize, the characteristic features of this third embodiment of the invention are: (a) the spacer/spring assembly 10″ is situated laterally on the shoe and the ground contacting portion of the spacer/spring assembly is positioned beneath the ball or heel of the user's foot; (b) the PAL2 functionality is realized by means of a rotating action, affected via the user's hand, and, (c) the ‘up configuration rotates the spacer/spring assembly backward and upward, toward the heel of the shoe.

Example 4

FIGS. 7a and 7b together illustrate a fourth embodiment of the invention. FIG. 7a shows the spacer/spring assembly in the ‘down’ orientation. FIG. 7b shows the spacer/spring assembly in the ‘up’ orientation. One of the noteworthy characteristics of this embodiment is that the wire form is configured in such a way as to rest against the sole of the shoe when in the ‘down’ position (FIG. 7a).

FIGS. 8a and 8b together illustrate a fifth embodiment of the invention. As with the previous case, FIGS. 8a and 8b respectively show the spacer/spring assembly in the ‘down’ and ‘up’ orientations. One of the characteristics of this embodiment is that the wire form does not rest against the sole of the shoe while in the ‘down’ position (FIG. 8a).

Both embodiments illustrated in FIGS. 7 and 8 possess two distinguishing features: the first feature is the use of apparatus components that are built-in to the shoe. The second feature is the use of secondary springs to ensure that both the ‘down’ and ‘up’ positions of the main spacer/spring assembly are stable.

The embodiments of these figures also illustrate several secondary, optional features for illustrative purposes. These concern the composition of the main spacer/spring and the location of the axle housings. Specifically, the embodiment of FIG. 1 possesses a main spacer/spring comprised of a tongue of spring steel or fiber-reinforced composite. This embodiment also uses an axle housing that is built-in (i.e. embedded) into the sole of the shoe.

By contrast, the embodiment of FIG. 2 possesses a main spacer/spring comprised of a ball of elastomeric material such as closed-cell polyurethane. This embodiment uses an axle housing that is affixed to the back heel of the shoe. In both cases, these secondary features are illustrative are not essential or necessary features of the respective embodiments; they are, in fact, interchangeable, and are shown for illustrative purposes only, to present several advantageous means to embody the broader aspects of the invention.

FIGS. 7a and 7b show an embodiment of the invention that is built-in to the shoe (20) and that utilizes secondary springs 14 to help establish the stable ‘down’ and ‘up’ positions of the main spacer/spring assembly.

FIG. 7a illustrates the ‘down’ position, in which the main spacer/spring 10 is positioned below the foot. FIG. 7b illustrates the ‘up’ position, in which the main spacer/spring 10 is positioned behind and above the heel of the foot.

The main spacer/spring 10 is connected to pivot system 11, which in this embodiment is comprised of a wireframe. The main spring 10 may be connected to the frame 11 in either permanent or impermanent manner, the latter facilitating replacement of the main spring for maintenance and repair.

Although it is shown in side profile in the figures, the wire frame 11 is essentially a bent rectangle of resilient material such as spring steel wire. Wire frame 11 has two free ends of wire whose proximal wire segments are bent at approximately 90 degrees to the rectangle, such that the free ends can be inserted into opposite ends of the axle housing 20 and thus establishing mating of the two sub-systems 11 and 20.

A notable feature of this embodiment resides in the shape of the wire frame 11. In the ‘down’ position, the rectangular portion of the wireframe rests against the sole of the shoe. The wire frame 11 thus positions the main spring 10 (to which it is attached) under the shoe as illustrated in FIG. 7a, thereby providing stability of the main spacer/spring under the foot.

The wire frame 11 also possesses attachment means 13—one on either side of the shoe (but with only one secondary spring 14 visible in the figures). Secondary 14 are stretched between fastening point(s) 12 on the wireframe and fastening point(s) 13 on the shoe. The latter point(s) 13 can be screwed into the material of the shoe or built-in to the shoe during manufacture.

In combination with the wire frame 10 and axle housing 20, the secondary springs 14 ensure that the ‘down’ and ‘up’ orientations of the spring assembly are stable while the in-between orientations are not stable. They also ensure smooth operating action of the spring assembly so that the user can transition smoothly between the ‘down’ and ‘up’ states.

The axle housing 20 is comprised of a metal or plastic tube that can be inserted into an existing shoe or that can be built-in to a specialized, purpose-built shoe during manufacture. For illustrative purposes, the axle housing 20 is embedded inside the material of the shoe. This is not a defining feature of the embodiment. Alternate locations for the axle housing, such as behind the heel, are also possible.

For similarly illustrative purposes, the main spacer/spring 10 shown in FIG. 7 takes the form of a tongue of spring-steel or fiber-reinforced composite. Again, this is for illustrative purposes and other types of main springs may also be used.

To summarize, the essential features of the embodiment of FIG. 7 are: (a) a wire frame that rests against the sole of the shoe, (b) a built-in axle housing that is embedded within the material of the shoe (not necessarily the sole); (c) secondary springs that establish the stability of the ‘down’ and ‘up’ orientations of the spring assembly.

FIGS. 8a and 8b show a second embodiment of the invention that is built into the shoe and that utilizes secondary springs to help to establish the stable ‘down’ and ‘up’ positions of the main spacer/spring assembly.

FIG. 8a illustrates the ‘down’ position, in which the main spacer/spring 10 is positioned below the foot. FIG. 8b illustrates the ‘up’ position, in which the main spacer/spring 10 is positioned behind and above the heel of the foot.

A key feature of this embodiment resides in the shape of the wire frame 11. This wire frame (shown in side profile in the figures) is essentially a bent rectangle with two free ends. In contrast to the wire frame of FIG. 7, the present wire frame is bent at greater than 90 degrees. As before the free ends of the wireframe are inserted into opposite ends of the axle housing 20. In this case however no part of the wireframe rests against the sole of the shoe when ‘down.’ Instead, and in contrast to the embodiment of FIG. 7, a gap remains between the wire frame and the sole of the shoe. This allows a portion of the main spacer/spring 10 to be positioned in contact with the sole of the shoe as illustrated in FIG. 8a.

The wire frame 11 also possesses attachment means for secondary springs 14—one on either side of the shoe (but with only one spring 14 visible in the figures). The springs 14 are stretched between fastening point(s) 12 on the wireframe and a fastening point(s) 13 on the shoe. The latter point(s) 13 can be screwed into the material of the shoe or built-in to the shoe during manufacture.

In combination with the wire frame 10 and axle housing 20, the secondary springs 14 ensure that the ‘down’ and ‘up’ positions of the spring assembly are stable and that the in between orientations are not stable. They also ensure smooth operating action of the spring assembly so that the user can transition smoothly between the ‘down’ and ‘up’ states.

The axle housing 20 is comprised of a metal or plastic tube that can be built-in to a specialized, purpose-built shoe during manufacture. For illustrative purposes, the axle housing 20 is affixed to the back of the heel of the shoe. The heel location of the axle housing 20 is not a defining feature of the embodiment, however. Alternate locations for the axle housing, such as inside the sole or heel are also possible.

For similarly illustrative purposes the main spacer/spring 10 shown in FIG. 8 takes the form of a spheroid of closed-cell polyurethane foam. This too is for illustrative purposes and other types of main springs are possible.

To summarize, the essential features of this embodiment are: (a) a wire frame that does not rest against the heel of the shoe but that allows a portion of the main spring to directly contact the sole of the shoe, (b) a built-in axle housing that is affixed to the material of the shoe (not necessarily the heel); (c) secondary springs that establish the stability of the ‘down’ and ‘up’ orientations of the spring assembly.

The above figures represent embodiments of the invention and in no way limit the general principle of the invention. For example, variants of the invention can be envisioned which are placed toward the front of the foot.

The invention can be embodied as a so-called ‘retrofit’ system that straps onto pre-existing footwear such as running shoes or to the user's bare foot or socked foot. Alternatively, the invention can be integrated within a customized shoe with pivot and actuating assembly being incorporated directly into the design of the shoe.

The invention enables enhanced locomotion with improved efficiency, ergonomics, and entertainment value of human foot-based locomotion. The invention is particularly well suited for skateboarding. Due to the two orientations of the spacer/spring assembly, a skateboarding user can quickly place the spacer/spring in the ‘down’ position when that foot performs a power-stroke against the ground and to place the spacer/spring assembly in the ‘up’ configuration when the same foot rests on the skateboard or when the user is off the skateboard.

Claims

1. A spring assembly attachable to a strap on a user's foot or shoe, comprising a pivot coupled to the strap configured to allow the spring assembly to pivot into a first quasi-stable orientation, whereby the spring assembly contacts the ground for spring-assisted use of the foot or shoe, and a second quasi-stable orientation, whereby the spring assembly does not contact the ground for normal, non-spring-assisted use of the foot or shoe.

2. The spring assembly of claim 1 wherein the pivot possesses a lever or handle that facilitates pivoting the spring assembly from the first to the second orientation and back.

3. The spring assembly of claim 1 wherein the pivot comprises a mechanism that provides for the first quasi-stable orientation to be further stabilized or momentarily mechanically locked under forces generated by the action of the foot or shoe contacting the ground.

4. The spring assembly of claim 1, further comprising additional housings, straps, and fastening means, configured to allow the spring assembly to be housed, strapped and fastened to a shoe.

5. The spring assembly of claim 1 wherein the spring assembly is integral to a shoe.

6. The spring assembly of claim 1, wherein the spring assembly is chosen from the group consisting of coil springs, wave springs leaf springs, solid composite springs, and wireframes; air bladders, rubberized materials, and solid or quasi-solid compressive materials.

7. The spring assembly of claim 1, wherein the spring assembly includes stiff members to effect ground-contact and shoe-contact of the spring assembly, the stiff members coupled by a compressive member comprising one or more of coil springs, wave springs, leaf springs, solid composite springs, wireframes; air bladders, other rubberized materials, and solid or quasi-solid compressive materials.