# Patent

## Title
Economical stilts

## Abstract

Two blocks of structural foam are fitted with shoe retaining straps with buckles. The blocks have ground contacting areas larger than the user's shoes for stability and to reduce the toss-over effects of stepping on construction junk on the floor. Small objects embed in the resilient surface of the foot so their effect on walking and stability are nullified.

## Background
RELATED APPLICATION
This application is a continuation of Ser. No. 11/378,112 “Economical Foam Stilts”, filed Mar. 18, 2006, now U.S. Pat. No. 7,374,514, which is hereby incorporated by reference, and claims the filing date of that application.


U.S. GOVERNMENT INTEREST IN THE INVENTION
None
BACKGROUND OF THE INVENTION
1. Field of the Invention
Walking platform for extending the reach of drywall installers, plasters, painters, arborists, fruit pickers, shelf stockers, inventory counters, etc.
2. Description of Related Art
Walking stilts for elevating painters and drywall installers so they can reach the ceiling of a room have been around for some time.
The essential parts of a drywall installer's stilt are a means to attach the stilt to the user's boot, a ground engaging foot structure, and a means to hold the boot attachment and the ground engaging foot apart in a vertically oriented relationship.
Various designs of these essential elements are described in the literature, some are on the market and in use by the construction industry.
Almost all are some form of fixed or articulated connection between the human's boot and a ground engaging foot. U.S. Pat. No. 5,645,515 by William Armstrong is typical. Many other examples of similar structures are easy to find in the patent data base.
These buckled on stilts are well made of cast and machined metal parts and thus are very expensive. Several hundred dollars per pair.
The ground engaging foot is invariably no larger than the shoe on the human foot, and in some examples, it is narrower and/or shorter. Most have some articulation so that the ground foot operates with a “natural” longitudinal toe to heel flexibility. None were found with lateral flexibility which would permit the wearer to sense the ground foot stepping on a piece of construction junk so the ankle could respond to, or possess capability to absorb the unevenness of stepping on construction junk and small items such as nails and drywall screws. As a result, falling is common and the extra height makes falling all the more likely to result in injury.
The dangers encountered in use, the cost, and an inappropriately designed ground foot has discouraged using the available stilts in other applications where extending height and reach would be a valuable asset.
U.S. Pat. No. 5,593,373 by Russell Hale overcomes the cost problem by using recycled buckets as the elevating platform. A bucket does provide more area than the human foot, but the ground engaging area is shaped differently. Also a bucket has marginal strength at the rim, and the sides may buckle under load. Buckets simply were not designed to be walked upon in the manner Hale describes.
Currently, good, strong, metal buckets are becoming scarcer. Plastic buckets are rapidly replacing metal buckets for nearly every use. Plastic buckets will have wider variation in shape, cross section, and material strengths. Choosing one that is strong enough to be used safely may be beyond the ability of Mr. Hale's targeted user.
Another problem with Mr. Hale's bucket stand is that the ground engaging portion is circular. This separates the extended feet. Since the buckets are axially vertical, the ground separation is directly translated to the wearer's foot positions. The wearer will have to “duck walk”, which is less stable, especially when gazing upwards.
Mr. Hale's bucket may step over construction junk, placing the junk inside the bucket rim. The next step might drag the junk, which may be attached to something, or simply be heavy, and cause stumbling. If a workman steps the rim on a nail, drywall screw, or similar object, a spot of high stress occurs on the rim. This could induce the bucket wall to buckle, which would quickly propagate into a total failure of the supporting bucket.
U.S. Pat. No. 7,070,023 “Adjustable Stilt” by Denny Waxler teaches a stilt assembly utilizing a 3 piece structure. The upper piece is a foam block topped by a shoe attachment. The mid assembly is a plastic structure of various lengths, and the lower (stilt foot) assembly has a sole (14) or base plate adapted to provide traction (see Waxier col 2, lines 44+) and probably, though not specifically taught, wear resistance. Waxler's three pieces are attachable to each other by pairs of “puzzle registry” devices. The “puzzle registry” device pairs are shown as distinct elements separate from and attached to the foam block element. This suggests that they are constructed of more durable material than foam for strength and safety reasons. Foam is unlikely to have sufficient strength in the small sections illustrated to withstand the loads imposed by a walking man.
Waxler's boot strapping appears to be a pair of straps (FIG. 1), one of which surrounds the wearer's leg and the other surrounds the wearer's ankle. There is no toe strap illustrated or referred to within the text. Waxier does not have plastic foam as the ground engaging element, as does the present invention. Thus, he would not have the feature of resiliency to yield to and enclose small stepped upon objects.
Waxler's ground engaging foot is a simple rectangular surface that is the same size as the boot holding surface. He does not utilize outwardly extending pieces to improve stability against tipping to the outside. Waxler's FIG. 1 shows the stilt extending a considerable distance, at least a boot width toward the inside, that is toward the other stilt. This causes the wearers feet to be spread unnaturally far apart, resulting in a “duck walk” and increasing the propensity to buckle outwardly.
The present invention also has an oversize ground engaging area, but it is full contact, shaped, and positioned relative to the wearer's foot that the wearer walks naturally and the effects of stepping on junk is minimized, and in some cases transferred to the foot as a natural feel of an irregular walking surface, which is automatically compensated for by the user's sensing and proprioceptor nerves and muscle system.
The inside surfaces of the present invention are close to the wearer's boot instep, thus they do not collide or interfere with setting a natural stance for the walker.
3. Objects of the Invention
It is an object of the invention to provide a platform attachment to the foot of a workman so that he may walk around the worksite elevated 1 to 2 feet over the floor.
It is another object of the invention to provide a stable platform for standing upon that has a ground engaging foot having an area at least as large as the user's boot.
It is another object of the invention to provide safety features to avoid leg and ankle damage if the user should fall off the height extending invention.
It is another object of the invention to be stable enough that a workman can with reasonable safely walk around with his hands and gaze over his head, especially while holding a tool or load.
It is another object of the invention to provide shoe fastening that may be buckled and unbuckled with one hand and not having to be within the eyesight of the user.
It is another object of the invention that the cost be low.
It is another object of the invention to provide a natural gait for balance and stability. Feet not abnormally separated.
It is another object of the invention to provide a walking platform that is intuitive to put on and intuitive to use; no significant learning curve.
It is another object of the invention to provide a walking platform relatively insensitive to walking over junk on the floor.
It is another object of the invention that there be no moving parts other than in the shoe buckling system.
BRIEF SUMMARY OF THE INVENTION
Two large blocks of structural foam are fitted with shoe engaging buckles comprising quick release hook and loop fastenings (IE VelcroTM). The user attaches his feet (shoes, boots) to the blocks and walks along carrying the blocks with him.
The general shape of the blocks is a rectangular parallelopiped. The axis of support is vertical, extending from the wearer's tibia bone and terminating at the ground under his foot.
The shoe platform is at least as large as the user's boot, and usually extends beyond the toe, heel, and each side of the user's boot. This boot platform area is projected to the ground contacting lower surface as the primary ground contacting foot. In addition, an laterally outward extension of the ground contacting foot is added at the heel for lateral stability. The extension is a block of the foam extending a distance approximately 2⁄3 the width of the foot and forward approximately 57% of the length of the foot.
The extension provides significant lateral stability as well as to moderate the effects of stepping on construction junk or in the case of an arborist, uneven ground.
The shoe attachment breaks away from the block or unlatches if the user should fall sideways. This protects the ankle and leg from being strained or broken due to lateral loads imposed by falling.



BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is an isometric view of the invention.
FIG. 2 is an isometric view of the invention using a post or strut structure to separate the stilt foot from the boot clamp.
FIG. 3 is an isometric view of an embodiment of the invention where the shoe straps and heel stop are anchored into the foam core block.



TABLE OF IDENTIFIED DETAILS


    
    
        1. The right-foot stilt in its entirety
        2. The core block of the stilt
        3. Heel stop
        4. Ankle strap
        5. Boot clamp base plate
        6. Boot toe strap
        7. Calf encircling strap
        8. Lateral stabilizing block and ground engaging surface
        9. Stabilizing post for calf encircling strap
        10. Primary ground engaging foot, ground engaging surface
        11. Boot support surface, upper surface
        12. Typical strut
        13. Strut mounting base
        14. Alternative separation means using struts
        15. Back (heel) vertical surface
        16. Outer vertical surface
        17. Front (toe) vertical surface (hidden in the FIG. 1 view)
        18. Inside vertical surface, interior vertical surface, facing sides of the core blocks, (hidden in the FIG. 1 view)
        19. Anchorage for the toe strap being internal to the core block.
        20. Rounded corners option.
    
    


DEFINITIONS
The following words are to be interpreted broadly and the definitions extend to all verbs, adverbs, adjectives, nouns, gerunds, tenses, etc. derived therefrom.
Boot—includes all kinds of footwear including oxford style shoes.
Foot—includes, depending on context, a shod human foot or the distal end of an appliance (the present invention) applied to a human foot and leg.
Buckle—any means for temporarily joining two straps or two ends of a strap. Includes hook-and-loop means, snaps, hooks, buttons, ring and tang buckles, friction buckling devices, etc.
Structural foam—any semi-rigid material having entrained air pockets and having sufficient strength for supporting a person in the configuration described herein. StyrofoamTM, by Owens Corning Company, or polystyrene foam slabs are the preferred material.
Rectangular parallelopiped—a solid where each of the 6 sides are rectangles. However, modification to the parallelopiped such as rounding (even severely rounding) the edges, or slightly tapering for manufacturing processing purposes will be considered as still being a parallelopiped for the purposes of this disclosure and attached claims.
Floor—any surface intended to be walked upon. Includes earth, concrete, grass, constructed floors, platforms, decks, etc.
DETAILED DESCRIPTION OF THE INVENTION
The design of the stilt described herein is adapted to be a natural walking surface elevated 1 to 2 or more feet above the floor. The ground engaging foot is resilient and can deform around small objects. The primary portion 10 of the ground engaging foot may be slightly larger than the sole of a boot, and has an extension to the outside that is about 2⁄3 the width of the boot platform. The lift is a solid block of structural type plastic foam, and the boot clamping means is primarily hook and loop fastening straps securely attached to the core block. One strap goes around the user's ankle and the other over the boot toe.
FIG. 1 shows the right stilt 1 of a left-right pair. The left stilt is identical except for being reversed across the heel-toe axis.
Core block 2 in the preferred embodiment is a solid block of structural foam. The upper surface 11 is large enough to accommodate a workman's boot. The upper surface width and length is usually only slightly larger than the largest boot expected to be accommodated, but may be as small as the boot sole. Six inches wide, and fourteen inches long has been found satisfactory for a 2 foot high stilt. A shoe binding adapter is securely attached to the upper surface of block 2. The adapter is comprising a heel stop 3, an ankle strap 4, and a toe strap 5.
The shoe binder is shown in FIG. 1 as being attached to a mounting base plate 5 which is then securely fastened to the core block 2 by glueing, pins, bolts, or casting into block 2, or some combination of these or similar. Gluing alone has been found to be an adequate fastening method. A leg brace comprising post 6 and calf encircling strap 7 is included for safety. While is possible to use the present stilts without the leg brace, the probability of falling off is reduced immeasurably by the extra anti-buckling characteristic of the leg brace.
FIG. 1 illustrates the hook and loop fastening as simple overlapping interconnection. Alternatively, the strap may be passed through rectangular rings or slots then folding back onto itself then fastening. This also is a very satisfactory way to route and fasten all the straps. Other buckling means may be employed as needed.
The lateral stabilizer block 8 extends from the outer face of the core block 2 approximately under the heel of the wearer's boot. Block 8 extends from the back edge of block 2 to approximately 55 to 65% of the length of block 2, and extends outwardly from the outer face of block 2 approximately 2⁄3 the width of block 2. Dimensions found satisfactory are 6×14 inches for the upper surface and the primary portion of the ground engaging surface, and stabilizing block 8 being 4 inches wide and 8 inches long.
The ground engaging foot is comprised of resilient material. The structural foam of the core block 2 has adequate resilience, therefore, the foot is simply the foam portion at the bottom of block 2. The resilience of the foot permits the foot to yield and enclose small objects, thereby nullifying the effects of stepping on them.
As illustrated in FIG. 1, the boot platform 11 and the ground engaging foot 8+10 are fixedly held one above the other coaxially, and in parallel orientation to each other. Note, this is a definitive characteristic of a rectangular parallelopiped shape. Because Block 2 has a margin around the boot, the primary area 10 of the bottom ground engaging foot is slightly larger than the boot, plus an additional area of the lateral stabilizing block 8.
ALTERNATIVE EMBODIMENTS AND VARIATIONS OF THE INVENTION
FIG. 1 shows the core block 2 and the side stabilizer block 8 as parallelopiped shaped with rectangular corners. There is no reduction in utility if the vertical edges of the core block and the stabilizing block are rounded, shown as 20 in FIG. 3, nor if the interior corners are filleted any convenient amount. A modest expansion of cross section from the boot surface to the ground engaging surface for the purpose of providing mold draft or similar is anticipated and does not change the function or override the objects of the invention nor is it intended that minor non-parallelism of block 2 edges or faces, or rounding of the edges, nullify the description of block 2 being described as essentially a rectangular parallelopiped shape.
Toe and ankle strapping 4 and 6, and the heel block 3 may be embedded within the core block 2, thereby eliminating the mounting base plate 5. FIG. 3 shows the toe strap embedded in the core through the top surface.
Stabilizing block 8 may be attached to the core block 2 by any convenient means such as glueing, integrally molded, bolts, pins, etc, or a combination of these and similar fastening methods.
The ground engaging foot is comprised of resilient material. In the preferred embodiment, the foot is integral to and comprised of the same foam as the rest of the core block 2. However, as an alternative, less desirable embodiment, the foot may be a separate block of 11⁄2 to 21⁄2 inches thick and the same shape and characteristics as described, but separated from the boot engaging means by a set of struts or other rigid structure. While structural foam is the preferred material, in all embodiments, the resilient material may be any other substance with the properties of yielding to enclose small objects on the floor when stepped upon.
This alternate embodiment is illustrated in FIG. 2, as item 1. Item 14, alternate separation means, comprising a set of struts or posts 12 attached to the boot clamp plate 5 and strut base 13, to which foot block 8&10 is attached, describes a alternative embodiment of the stilt.
How to Use the Invention
Using the present invention is entirely intuitive. The blocks are strapped on the feet (boots) and one simply stands on the flat upper surface. As one walks, the blocks follow in a natural way, and because the ground engaging foot does not extend significantly beyond the boot toe, the striding motion even rocks naturally on the toe (forward) and heel edges.
The user's feet stand upon a flat surface parallel to the floor, and the stability of the floor engaging means is greater than that of a boot alone, thus the sensation and subsequent balance is the same as or nearly identical to standing on the floor itself. This permits the user to do the activities he would do from the floor such as looking and/or reaching upward while moving about. He should exercise at least the same care on the stilts as when moving on the floor with the same attitude.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to falling within the scope of the invention as defined by the claims which follow.

## Claims

1. A pair of asymmetrical stilts for raising a walker above a floor comprising:
a. Each stilt comprising an approximately rectangular core block of structural foam material serving as the core structure of each stilt,
b. each rectangular core block being one piece comprising a planer upper surface having a means to removably attach a boot to said upper surface, and an opposite ground engaging surface approximately the same size and shape as said upper surface,
c. said upper surface having edges proximal to the boot heel, toe, inner side, and outer side, and said ground engaging surface having edges essentially parallel to the corresponding upper surface edges, and vertical surfaces extending between said upper edges and lower corresponding edges, whereby when the pair of stilts is worn by a walker, the walker's stance is normal, when standing his legs are in normal vertical alignment, and when walking said interior edges and surfaces of said rectangular core blocks do not collide,
d. said ground engaging surface further having an extending ground engaging surface extending outwardly from the outer edge and forwardly from the heel edge toward the toe edge and coplanar with said ground engaging surface of said rectangular core block, thereby adding lateral stability to the stilt in the outward direction.

2. The stilt of claim 1 where the vertical corner edges of said rectangular core blocks are rounded.

3. The stilt of claim 1 where the rectangular core blocks each further comprising a single block of structural foam extending from said upper planer surface to said lower ground engaging surface.

4. The stilt of claim 1 where said ground engaging surface has yielding capability for yielding around and enclosing stepped upon small objects.

5. The stilt of claim 1 where said boot attachment is comprising an ankle restraining strap, a toe restraining strap, and a heel positioning bracket for positioning said boot on said upper surface, where said straps and heel positioner are anchored to the foam core by having portions embedded within the rectangular foam core block.

6. A pair of asymmetrical stilts for raising a walker above a floor comprising:
a. a pair of approximately rectangular blocks of structural foam material each serving as the core structure of each stilt, and
b. each rectangular block being one piece and having an upper planar surface with means to removably attach a boot to said upper surface, and a first ground engaging surface opposite said upper surface approximately the same size and shape as said upper surface, and
c. said upper surface having edges proximal to the boot heel, toe, inner side, and outer side, and said ground engaging surface having edges essentially parallel to the corresponding upper surface edges, and vertical surfaces extending between said upper edges and lower corresponding edges, whereby when the pair of stilts is worn by a walker, the walker's stance is normal, when standing his legs are in normal vertical alignment, and when walking the walker's legs are in normal parallel alignment, and
d. said first ground engaging surfaces further having a second ground engaging surface extending outwardly from the outer edge and forwardly from the heel edge toward the toe edge and coplanar with said first ground engaging surface, thereby adding lateral stability to the stilt in the outward direction, and
e. said first and second ground engaging surfaces further having the capability of yielding to stepped upon small objects and surrounding said objects, receiving them into said ground engaging surface, thereby causing the walker to be insensitive to stepping on small objects.

7. The stilt of claim 6 where the vertical corner edges of said rectangular core blocks are rounded.

8. The stilt of claim 6 where the rectangular core blocks each further comprising a single block of structural foam extending from said upper planer surface to said lower ground engaging surface.

9. The stilt of claim 6 where said boot attachment means comprising an ankle restraining strap, a toe restraining strap, and a heel positioning bracket for positioning said boot on said upper surface, where said straps and heel stop are anchored to the rectangular foam core block by having portions embedded within the foam core block.

10. Each stilt of claim 6 where said outwardly projecting block of foam extends forwardly from the outer edge of the back surface a distance between 55% and 65% of the length of the upper surface, and outwardly a distance approximately 2⁄3 the width of the upper surface, and the lower surface of said projecting block being coplanar with the lower surface of said rectangular foam core block.

11. A pair of asymmetrical stilts for raising a walker above a floor comprising:
a. a pair of approximately rectangular core blocks of structural foam material serving as the supporting cores of each stilt, and
b. each foam rectangular core block having an upper planer surface having means to removably secure a shoe to said upper surface and an opposite ground engaging surface approximately the same size and shape as said upper surface, and
c. each said rectangular core foam block extending as one continuous piece from said upper surface to said ground engaging surface, and
d. said upper surface having edges proximal to the shoe heel, toe, inner side, and outer side, and said ground engaging surface having edges essentially parallel to the corresponding upper surface edges and vertical surfaces extending between said upper edges and lower corresponding edges, and
e. whereby when the pair of stilts is worn by a person, the person's stance is normal, when standing, his legs are in normal vertical alignment, and when walking his legs are in normal vertical alignment, and
f. each stilt further comprising a stabilizing block of foam extending outwardly from the lower portion of the outer side of said foam rectangular core block, said stabilizing block having one surface co-planer with said ground engaging surface of said core foam block, thereby being an outward extension of said ground engaging surface.

12. Each stilt of claim 11 where said ground engaging surface is comprised of foam having yielding capability for yielding around and enclosing stepped upon small objects.

13. Each stilt of claim 11 where said shoe attachment means comprising an ankle restraining strap, a toe restraining strap, and a heel stop for positioning and removably attaching said boot on said upper surface, where said straps and heel positioned are anchored by having portions embedded within said structural foam rectangular core block.

14. Each stilt of claim 11 where said outwardly projecting block of foam extends forwardly from the outer edge of the back surface part way toward the outward edge of the front surface of said foam rectangular core block.