Patent Application of

Tan-sen Tillson

Base For Ladder Which Prevents the Ladder from Sliding or Tipping on Uneven Surfaces

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to foundation structures and to ladder stabilizers on which the ladder is placed to reduce the possibility of slipping or tipping.

2. Description of Prior Art

There are many patents that describe means for stabilizing ladders, most of which attach to the ladder, such as the U.S. patent 7,216,742 issued to G. Spengler. That patent describes a ladder with an additional two legs, which can be drawn away from the regular ladder, but this ladder is not suitable for all ground conditions and adds weight to the ladder.

U.S. Pat. No. 3,891,054 issued to Clayton E. Larson in 1975 discloses a step ladder stabilized by channel members which are fixed on each side of the lowest rung of the ladder and have an extendable member. Braces are provided at the upper rungs to provide rigidity and resistance against sway. However, it is not adjustable to all site conditions and adds very little stabilization to the ladder.

U.S. Pat. No. 4,964,488 issued to John V. Stewart on Oct. 23, 1990 discloses a step ladder stabilizer for a step ladder comprising a brace hinged to a ladder rail and an arm hinged to the rail at a lower position trussing the brace. The stabilizers on each

side of the ladder fold against the front of the ladder. However, this ladder stabilizer is not adjustable to all site conditions and it interferes with the use of the ladder when not in use.

U.S. Pat No. 5,868,222, issued to Francois Charbonneau on Feb. 9, 1999 discloses an extension ladder having a telescopic tube mounted to each side of the ladder's lower section and a lateral brace to support the telescopic tube extending away from each side of the ladder. However, the telescopic tubes bolt to the ladder which may compromise the integrity of the ladder, it is not easily installed on the ladder, and it is cumbersome and inconvenient to use. Also, it has removable pins and clips which are easily lost.

Other patents describe independent support means for supporting the ladder. U.S. Pat. No. 5,857,544 issued to Robert Del Sole discloses an independent support having splayed arms, which contact with the ground and an attached assembly which holds the ladder at a given angle.

U.S. Pat. No. 5,078,231 issued to Albert N. Davis, et al. describes a plate or platform on top of which the ladder can be placed. As the plate in this invention is flat, it is not suitable for rough or irregular terrain, as is the present invention, herein disclosed. The raised ridge that prevents the ladder from slipping back is already well known to the art, as it is a standard practice of ladder users to peg a board behind the base of the ladder to secure it.

What is needed is a support system which is independent of the ladder and can be put in place prior to placement of the ladder. This ensures that there is a level and secure surface, and ensures that the ladder is not leaning to one side prior to being adjusted.

What is needed is a support system which is portable and light and does not add weight to the ladder, which otherwise makes it more difficult to adjust.

What is needed is a support system which maximizes the surface area contact between the ground and the support.

What is needed is a support system which conforms to the irregularities of the ground and grips these to provide additional support.

What is needed is a support system which becomes more secure as the weight of the ladder and occupant increases.

SUMMARY OF THE INVENTION

The invention is a portable plate which is connected to one or more flexible bags or bladders, which are located beneath the plate, and which in turn are filled with granular particles. These particles can be of any material, size or composition, for example plastic particles, sand, rubber or other materials, preferably exhibiting high friction, especially when compacted and/or compressed. The preferred embodiment includes particles or pieces of fill, with high coefficients of friction and which are shaped to entangle when pressure is exerted on them, but flow when the pressure is relieved. These objects generally have the feature that they are or contain "U" shapes or contours; or have a series of "U" shapes or contours, sometimes twisted, which hook-up with each other when compressed, but flow freely when not compressed. This shape of the fill can be any irregular form, for example, Platonic solids: tetrahedron, octahedron, hexahedron (cube), icosahedron and dodecahedron. For example, they may be shaped like those forms that have been found to be suitable for hydraulic armor walls, such as a dolos (see Fig. 3) or accropodes ™, such as the Core- loc ™ which was developed the U.S. Core of Engineers. The principal characteristic of the dolos, accropodes ™ is that they provide high frictional cohesion under pressure and more importantly, entangle and lock together under pressure, but flow reasonably when Ae pressure is relieved. Thus any form that is used for hydraulic armor walls will most likely be suitable for the purpose.

The support system 1 is first held by a handle 2c and pumped up and down, and back and forth on the irregular surface to allow the fill 4 and the flexible bladdeφ) 3 to accommodate to the irregular surface 5 on which the support is placed and to position the plate 2 so that it is approximately level, leaning slightly in the same direction as the lean of the ladder 6 or other suitable angle for the purpose. Some embodiments of the invention include a level(s) 2e, such as the round type, to guide this procedure.

The user may then press their foot against the plate, compacting the fill. The user may then place the ladder on the plate, so that it rests on the plate and the proximal end leans against the plate ridge 2a. Although the ridge may be placed at any place on the plate, in the preferred embodiment it is placed so that it is closer to the edge of the plate, closest to the wall to which the ladder is set, to prevent the whole support system 1 from rolling.

The surface of the plate may be textured or contain additional ridges and may be surfaced with rubber, or some other suitable material which prevents slipping. Some preferred embodiments of the invention utilize a plastic plate(s), into which any texture and protuberances may be molded, although any material that is sufficiently strong, may be utilized, and this may form an integral part of the bladders)

The bottom surface of the bladder may also contain protuberances 3a such as ridges, pegs or other devices, well know to the art to maximize the friction between the bladder and surface on to which it is placed. In some preferred embodiments of the invention, the bladder is made of a course and durable fabric, which provides a high frictional, but compliant surface. The bladder may be slightly elastic to better contain the fill, but in some preferred embodiments, the bladder is not appreciably elastic.

The bottom surface of the plate, which comes into contact with the fill, may also have protuberances 2b which interact with the fill and lock the two together, especially when downward pressure is applied to the plate, by the action of the ladder. This prevents the plate from sliding along the top of the fill in response to lateral forces, exerted due to the angle of the ladder.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view of the support system 1.

Fig. 2 is a cross-sectional perspective view of the support system 1, which illustrates the interlocking fill 4.

Fig. 3 is a perspective view of a dolos, which is an example of a fill 4 which can flow under low pressure, but entangles, locking together and forming a solid when compacted. These types of fill 4 are used in some preferred embodiments.

Fig. 3a is a perspective view of a particle shape 4b of a fill 4 which entangles with like shaped particles.

Fig.4 is a perspective view of a patch of irregular ground 5, on which the support 1, and ladder 6 may be placed.

Fig. 5 is a cross-sectional perspective view of the support system 1, which has accommodated to the shape of the irregular ground 5, but whose aggregate fill 4 has locked together under pressure forming a solid support.

Fig. 6 is a cross-sectional perspective view of the support system 1, in which the bladder 3 has a tunnel 7, which reduces the weight and amount of fill 4 but maintains a path 7a between the bladder pontoons 8, 8a for the fill to flow from one to the other 7b, to compensate for the uneven ground. Only part of the fill 4 is illustrated for diagrammatical clarity.

Fig. 7 is a cross-sectional perspective view of a number of stacked support systems 1, which can be stacked to form a larger structure.

Fig. 8, 8a and 8b illustrate how a support system 1, of the type illustrated in Fig. 6 with a socket 9, and opposed tunnel 7 can be stacked and locked together to form a larger structure. Only part of the fill 4 is illustrated for diagrammatical clarity.

Fig. 9, 9a and 9b illustrate how a support system 1, of the type illustrated in Fig. 6 and Fig. 8, 8a and 8b, with socket 9, and opposed tunnel 7 can be stacked and locked together. Only part of the fill 4 is illustrated for diagrammatical clarity.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Fig. 1 illustrates the support system 1 being comprised of a plate 2, with a back supporting ridge 2a, handle 2c, bladder 3 and bladder grips 3a. The plate 2 may be

incorporated into, attached or connected to the bladder 3 by means well known to the art, such as adhesives and mechanical connections. The plate 2 and bladder 3 may be of any convenient size, and may be used alone or in combination with others. That is, two small support systems 1 may be used for each leg of the ladder 6 or scaffold, rather than one for both. Or a single support system 1 may have any number of small bladders 3, rather than one large bladder 3. The ridge 2a may be formed into the plate or be a separate component that is attached to it by means well known to the art. While the ridge 2a illustrated in Fig. 1 is positive, extending above the surface of the plate 2, it is to be understood that the ridge may be negative, forming a groove or well(s) in the plate 2, collectively referred to herein as a "ridge", all being within the ambit of the invention.

Fig. 2 illustrates a support system 1 with fill 4, which in this case is a three dimensional star shaped fill, of various sizes. Fig. 2 also illustrates protuberances 2b, which may for example be pegs or ridges, which may be formed into the plate 2 and which lock into the fill 4, ensuring that the there is no creep or sliding along the boundary of the fill 4 and the bottom of the plate 2. It is to be noted that these protuberances 2b may take any form well known the art and still be within the ambit of the invention.

Fig. 3 and Fig. 3a illustrate two example shapes for the fill 4, which is a dolos 4a and shape 4b, respectively. Both these examples provide excellent flow under low pressure, but entangles to provide a solid foundation under the pressure of the ladder and user. These shapes also can have high frictional characteristics and allow for water drainage between the shapes, even when compacted.

Fig. 4 illustrates the type of uneven terrain for which the support system 1 is ideal.

Fig. 5 illustrates how the ladder 7 is supported by the support system 1. The bladder 3 accommodates to the irregular and sloping ground 5 and the plate 2 remains level.

Fig. S also illustrates the method of causing die fill 4 to flow into the desired conformation to provide an intimate cohesion between the bottom of the bladder 3 and the irregular ground 5. The operator need only pull the handle 2c in an up and down,

and back and forth motion 2d to cause the fill to flow. Once the bladder has made the necessary accommodation 3b to the ground topography, the user may step on the plate 2 to lock the fill into a solid like mass. The ladder 6 may now be placed on the surface of the plate 2. As the user steps up the ladder and exerts a downward force on the plate, the fill is further compacted and entangled, causing it to further solidify.

Once the user has completed the work, he may lift the handle 2c and the support system 1 may be moved to a new position or easily stored.

Fig. 6 is illustrates a support system 1, in which the bladder 3 has a tunnel 7, which reduces the weight and amount of fill 4 but maintains a path 7a between the bladder pontoons 8, 8a for the fill to flow from one to the other 7b, to compensate for the uneven ground. The tunnel 7 may be of any convenient size to permit the easy flow 7b of fill 4, while at the same time reducing the amount of fill required. Much of the supporting force for the ladder rails lies beneath the bottom ends of the rails, and thus the space between them 7 need not provide as much support. Therefore, the bladder 3 need not be as extensive in this intermediate location 7. As can be appreciated, some preferred embodiments of the invention use several separate and smaller bladders in place of a single large bladder, some or all of which may be connected with a connecting path 7a, all of which are within the ambit of the invention.

Fig. 7 illustrates how any number of support systems 1 can be stacked and interlaced to form a larger structural body. This resembles a wall of sandbags, but the difference is that the material 4 in the bladders is comprised of doloses 4a including other shaped objects having "U" shaped curves, which entangle, such as barbells, jacks or other interfering shapes which are well known to the art. As can be appreciated, these embodiments of the invention can be formed into any structural body or form and used for many purposes, such as a sea wall, foundation, retaining wall etc. In some embodiments of the invention, the outer surfaces of the bladder may have hook and loop patches which assist in locking the bladders together, while others may incorporate the hooks and corresponding loops into the weave of the material forming the bladder 3.

Fig. 8a and 8b illustrate how a support systems 1, of the type illustrated in Fig. 8 with sockets 9 (formed from a bladder in some embodiments), and opposed tunnels 7 can be stacked and locked together to form a larger structure. While the embodiments illustrated in Fig. 8, 8a and 8b have a connecting path 7a running between the bladders 8, 8a, it is to be understood that some embodiments of the invention do not have any such path 7a.

Fig. 9, 9a and 9b illustrate how a support system 1, of the type illustrated in Fig. 6 and Fig. 8, 8a and 8b, with socket 9, and opposed tunnel 7 can be stacked and locked together by inverting some of the units. The size and shape of the bladders 3 may vary to allow for various locking combinations, and all are within the ambit of the invention. It should also be noted that the perimeter of the bladders 3, may be shaped like interlocking jig saw pieces or interlocking paving stones to assist in keeping the support systems 1 together. Either or both of these methods may be utilized for locking the support systems 1 together, in addition to methods well known to the art, such as lashing, mechanical fasteners etc., and all are within the ambit of the invention.

It should also be noted that some preferred embodiment have plates 2, while others simply rely on the bladder surface itself. Other embodiments of the invention have separate plates 2, one for each of the base ends of the ladder rails or multiple objects that are supported.

While the examples of the invention have been in relation to supporting ladders and scaffolding, it should be appreciated that the support system 1 may be used for any purpose of providing a secure platform or working surface and be within the ambit of the invention.

While the examples of the invention have been to provide a platform that is level or horizontal, it should be appreciated that the user may set the platform to any angle required and be within the ambit of the invention.

While examples of the invention have been in relation to providing secure platforms, it is to understood that some embodiments of the invention are comprised of any

number of bladders 3, of various sizes and shapes, which in turn may form any shaped body or structure.

While examples of fill 4 have been provided that flow in low pressure conditions, but have high frictional characteristics and/or entangle together to form a solid mass when compacted by pressure, it should be understood that any aggregate material that has one or more of these characteristics is within the ambit of the invention.

While a number of preferred embodiments for the invention have been described, each having certain elements, it is to be understood that other preferred embodiments can incorporate any number or combination of these elements and come within the ambit of this invention.

While the present invention has been described in conjunction with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the inventions and appended claims.

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