Economical foam stilts

Two blocks of structural foam are fitted with shoe 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.

RELATED APPLICATION

U.S. GOVERNMENT INTEREST IN THE INVENTION

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 machined 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 on a nail, drywall screw, or similar, 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.

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.

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 Velcro™). The user attaches his feet (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 ⅔ 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.

TABLE OF IDENTIFIED DETAILS

1. The right-foot stilt in its entirety

2. The core block of the stilt

3. Heel stop

5. Boot clamp base plate

6. Boot toe 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

13. Strut mounting base

14. Alternative separation means using struts

15. Back (heel) vertical surface

16. Outer vertical surface

18. Inside vertical surface, interior vertical surface, facing sides of the core blocks, (hidden in theFIG. 1view).

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. Styrofoam™, 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.

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 portion10of the ground engaging foot may be slightly larger than the sole of a boot, and has an extension to the outside that is about ⅔ 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 lift block. One strap goes around the user's ankle and the other over the boot toe.

FIG. 1shows the right stilt1of a left-right pair. The left stilt is identical except for being reversed across the heel-toe axis.

Core block2in the preferred embodiment is a solid block of structural foam. The upper surface11is 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 block2. The adapter is comprising a heel stop3, an ankle strap4, and a toe strap5.

The shoe binder is shown inFIG. 1as being attached to a mounting base plate5which is then securely fastened to the lift block2by glueing, pins, bolts, or casting into block2, or some combination of these or similar. Gluing alone has been found to be an adequate fastening method. A leg brace comprising post6and calf encircling strap7is 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. 1illustrates the hook and loop fastening as simple overlapping connection Having the strap pass through rectangular rings or slots then folding back onto itself then fastening is also a very satisfactory way to route and fasten all the straps. Other buckling means may be employed as needed.

The lateral stabilizer block8extends from the outer face of the lift block2approximately under the heel of the wearer's boot. Block8extends from the back edge of block2to approximately 55 to 65% of the length of block2, and extends outwardly from the outer face of block2approximately ⅔ the width of block2. Dimensions found satisfactory are 6×14 inches for the upper surface and the primary portion of the ground engaging surface, and stabilizing block8being 4 inches wide and 8 inches long.

The ground engaging foot is comprised of resilient material. The structural foam of the lift block2is has adequate resilience, therefore, the foot is simply the foam portion at the bottom of block2. The resilience of the foot permits the foot to yield and enclose small objects, thereby nullifying the effects of stepping on them.

As illustrated inFIG. 1, the boot platform11and the ground engaging foot8+10are 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 Block2has a margin around the boot, the primary area10of the bottom ground engaging foot is slightly larger than the boot, plus an additional area of the lateral stabilizing block8.

ALTERNATIVE EMBODIMENTS AND VARIATIONS OF THE INVENTION

FIG. 1shows the lift block2and the side stabilizer block8as parallelopiped shaped with rectangular corners. There is no reduction in utility if the vertical edges of the lift block and the stabilizing block are rounded, 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 block2edges or faces, or rounding of the edges, nullify the description of block2being described as essentially a rectangular parallelopiped shape.

Toe and ankle strapping4and6, and the heel block3may be embedded within the lift block2, thereby eliminating the mounting base plate5.

Stabilizing block8may be attached to the lift block2by 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 lift block2. However, as an alternative, less desirable embodiment, the foot may be a separate block of 1½ to 2½ 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 inFIG. 2, as item1. Item14, alternate separation means, comprising a set of struts or posts12attached to the boot clamp plate5and strut base13, to which foot block8&10is 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 embodiments of the invention in which an exclusive property right or privilege is claimed are defined as follows: