FIELD OF THE INVENTION
Embodiments of the invention relate to a staircase to be installed in the interior of a swimming pool, and in particular, to a modular staircase constructed from sheets of material having notches that interweave with each other.
BACKGROUND OF THE INVENTION
Presently, it is known to use various types of steps or staircases in the interior of a swimming pool to allow swimmers to gain access to and exit the swimming pool. One design characteristic of such staircases is the ability to withstand the forces caused by both water pressure within the pool and by the weight of people using the staircase. Another design characteristic is the ability of the staircase to look aesthetically pleasing in the pools. For example, one type of swimming pool may include a “vinyl liner-type” swimming pool. A vinyl liner-type swimming pool is often lined in a sheet of blue-colored vinyl to make the pool appear blue. Thus, if a staircase is to be used in a vinyl liner-type pool, it may be desirable to line the staircase in vinyl such that the staircase blends into the pool walls and looks aesthetically pleasing. And finally, another design characteristic is the ability of the staircase to be used in swimming pools having different shapes or sizes. There may be small pools and large pools, or pools having curved or straight walls (or a combination of the two). Each shape of pool may require a different shaped staircase. It may be desirable to provide a staircase that can be constructed or modified to fit pools having various shapes.
One style of staircase that is often used in swimming pools constructed of concrete (or gunnite) is a concrete-filled staircase. The concrete-filled staircase is built on-site using a step form. The step form is filled with concrete, and when the concrete has set and dried, the step form is removed. Manufacturing concrete steps is expensive and labor intensive, and requires highly skilled workers for construction. Additionally, when concrete-filled steps are used in vinyl liner-type swimming pools, variations in the shape of the steps may make it difficult to cover the steps in vinyl. The uncovered concrete steps may not be aesthetically pleasing.
Another style of staircase is a one-piece molded plastic staircase. Such one-piece staircases have minimal structure to support the weight of swimmers and water pressure forces, and as a result, one-piece staircases have size limitations. Specifically, as the size increases, one-piece staircases lose stability. It is also expensive to manufacture such one-piece staircases, because a separate mold is required for each style and shape of staircase. Simple variations between staircases (for example, the addition or subtraction of a step or the curve of a pool wall) would require a completely new (and expensive) mold. One-piece staircases may be large and irregularly shaped, which may make them difficult to transport and handle. Finally, one-piece staircases may have face plate systems that are not typically covered with a vinyl sheet, which may not be aesthetically pleasing.
Other known staircases are constructed of steel or other metals. Such staircases are often assembled using mechanical fasteners such as screws and bolts. The use of such mechanical fasteners increases assembly time, and thus, increases the overall cost of the staircase. Additionally, the mechanical fasteners are easy to lose and may require the use of special tools to assemble. Finally, the use of steel or other metals is not preferred because metals corrode and rust when used in a pool.
There is a need for a staircase that is adaptable to vinyl liner-type swimming pools.
There is a need for a staircase for use in a pool that is structurally sound and resistant to forces caused by either water weight or users on the staircase, regardless of the size and shape of the staircase.
There is a need for a staircase for use in a pool that is easy to assemble.
There is a need for a staircase made from a non-corrosive material, such as polymer.
There is a need for a staircase that is modular, and thus provides parts that interchange with one another to fit pools having different shapes and sizes.
There is a need to reduce costs associated with special tooling and/or molds used to make the staircase.
SUMMARY OF THE INVENTION
Embodiments described herein provide a staircase assembled from components that have notches to fit into and interweave with each other. Specifically, one embodiment of a staircase described herein has a plurality of webs, and the perimeter of each web resembles a staircase with steps. The webs may be coupled together by sets of cross-beams. Each of the webs and the cross-beams may have notches that fit into and interweave with each other to form the basic structure of a staircase. The staircase may also be provided with cover pieces to cover the exposed webs and cross beams. The cover pieces provide a smooth and complete surface for a user to sit or step on, and for the vinyl liner to cover. Embodiments of staircases described herein are modular, in that they may be coupled together in various configurations and thus installed in a pool having straight walls, curved walls, or a combination of the two. Additionally, embodiments of staircases described herein may be installed in either vinyl liner-type pools or concrete pools.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure directed to one of ordinary skill in the art is set forth more particularly in the remainder of the specification. The specification makes reference to the following appended figures, in which use of like reference numerals in different features is intended to illustrate like or analogous components.
FIG. 1 shows a front plan view of a web according to certain embodiments.
FIGS. 2A-C show front plan views of various embodiments of cross-beams according to certain embodiments.
FIG. 3 shows a front plan view of a cover piece according to certain embodiments.
FIGS. 4 and 5 show an exploded view of a staircase according to certain embodiments.
FIG. 6A shows a perspective view of an assembled staircase according to certain embodiments, and FIG. 6B shows a cross-sectional view of the staircase in FIG. 6A.
FIGS. 7A and 7B show perspective views of an assembled staircase according to other embodiments.
FIG. 8 shows a partially exploded view of the staircase shown in FIGS. 7A and B.
FIG. 9 shows embodiments of webs that may be used in the staircase shown in FIGS. 7A and B.
FIG. 10 shows an embodiment of a back-piece, and embodiments of cross-beams that may be used in the staircase shown in FIGS. 7A and B.
FIG. 11 shows certain embodiments of cover pieces that may be used in the staircase shown in FIGS. 7A and B.
FIGS. 12A and 12B show perspective views of an assembled staircase according to yet another embodiment.
FIG. 13 shows a partially exploded view of the staircase shown in FIGS. 12A and B.
FIG. 14 shows one embodiment of a back-piece and one embodiment of a web that may be used in the staircase shown in FIGS. 12A and B.
FIG. 15 shows certain embodiments of cover pieces that may be used in the staircase shown in FIGS. 12A and B.
FIG. 16 shows certain embodiments of cross-beams that may be used in the staircase shown in FIGS. 12A and B.
FIGS. 17A-F show alternative embodiments of staircases according to the invention.
DETAILED DESCRIPTION
Embodiments described herein relate to a staircase that can be installed in a swimming pool. For example, the staircase 10 in FIG. 6B is installed against a generally flat wall 100 of a swimming pool, whereas the staircases 110 and 150 in FIGS. 7 and 12 are installed against a generally curved wall 112 of a swimming pool. The staircases are modular in that each staircase is assembled from multiple components. The components may be assembled in different configurations to provide staircases having different shapes and/or sizes. Additionally, multiple staircases may be coupled to one another to fit swimming pools having different shapes and/or sizes. The staircases 10, 110, 150 shown in the figures may be constructed in generally the same manner as described herein. Thus, although the following disclosure refers generally to staircase 10, it should be understood that the disclosure also applies to staircase 110 or 150 (unless otherwise noted). Additionally, it should be understood that although the following disclosure is related to swimming pools, the same general principles may be applied to staircases for use in other applications. (Such as the use of a staircase to exit or enter a building or other structure.)
FIGS. 1-3 illustrate the basic components of certain embodiments of staircases 10 described herein. Specifically, FIG. 1 shows a web 12, FIGS. 2A-2C show various types of cross-beams 40, 50, 60, and FIG. 3 shows a cover piece 70. The web 12 in FIG. 1 is defined by a back edge 20, a bottom edge 22, and steps 14A-C. Webs 12 according to other embodiments may have other shapes (such as the webs shown in FIGS. 7 and 12). The bottom edge 22 of the web 12 may be straight (as shown in FIG. 1), or may have another desired shape. For example, in certain embodiments the bottom edge 22 may have a notch or recess that defines two “feet” along the bottom edge. Such an embodiment may be desirable in order to conform to the floor of a swimming pool that is not necessarily level. The back edge 20 of the web 12 may include any number of notches 34, 36. As explained in more detail below, it may be desirable to provide a first notch 34 with a different configuration than the second notch 36. For example, in FIG. 1, the first notch 34 has a greater height and a smaller width than the second notch 36.
The web 12 shown in FIG. 1 has three steps 14A-C, wherein step 14A is closest to the pool floor 102 and step 14C is closest to the waterline 104 (as shown in FIG. 6B). It should be understood that having three steps 14A-C is non-limiting, and other webs 12 may be provided with other numbers of steps 14. As shown in FIG. 1, each step 14A-C of the web 12 is defined by a rising edge 16 and a running edge 18. In certain embodiments, the rising edges 16 may be provided with rising notches 24 and the running edges 18 may be provided with running notches 26. In FIG. 1, there are two rising notches 24 and two running notches 26 provided on each step 14A-C. But the number of notches 24, 26 is non-limiting. The web 12 may also be provided with a liner retention notch 23 between successive steps 14A and 14B, and between steps 14B and 14C.
Additionally, in certain embodiments the web 12 is provided with cut-outs 30 that include notches 32. The notches 32 may receive cross-beams 50 to provide additional structural support proximate to the bottom edge 22 of the staircase 10. It may be desired to provide a larger shape for cut-out 30 in order to provide room to insert and manipulate the cross beams 50 that are received in the notches 32. Finally, in certain embodiments the web 12 is provided with pre-drilled apertures 28 to receive fasteners to couple a spacing piece 80 to the web 12. The spacing piece 80 is shown in FIGS. 4-6 and described in more detail below. It should be understood that the pre-drilled apertures 28 are not necessary, however, and in other embodiments the spacing piece 80 is coupled to the web 12 by other means.
FIGS. 2A-C show different types of cross-beams 40, 50, 60 that may be used in embodiments of the staircase 10. Each of the cross-beams 40, 50, 60 may be any desired length. FIG. 2A shows a mounting cross-beam 40 that may be received within the first notches 34 along the back edge 20 of the web 12. The mounting cross-beam 40 may be used to mount or secure the staircase 10 to the wall 100 of a pool, as shown in FIGS. 6A-B. Mechanical fasteners, adhesive, or other means may be used to secure the mounting cross-beam 40 to the notches 34. In other embodiments, the mounting cross-beam 40 may include notches to fit into corresponding structure within notch 34.
FIG. 2B shows a first cross-beam 50 having notches 52, and FIG. 2C shows a second cross-beam 60 having notches 62. There is an overhang 53, 63 on each end of the cross-beams 50, 60. As shown in FIG. 5, when the cross-beams 50, 60 are assembled with the webs 12, the overhangs 53, 63 may protrude on one side of the web 12. In certain embodiments, the second cross-beam 60 is slightly taller than the first cross-beam 50. (Additionally, and as explained in more detail below, the notches 62 of the second cross-beam 60 may be longer than the notches 52 in the first cross-beam 50.) But in other embodiments, the first cross-beam 50 may have a height that is greater than or equal to the height of the second cross-beam 60.
The specific placement of the first and second cross-beams 50, 60 within the webs 12 is not critical. In certain embodiments, however, it may be desirable to assemble the first cross-beams 50 proximate to the upper steps 14C of the staircase 10, and the second cross-beams 60 proximate to the lower steps 14A. Such an assembly may be desirable in order to provide more structural stability against forces caused by water weight and users on the staircase 10. Specifically, the second cross-beam 60, which may be taller than the first cross-beam 50, may be assembled proximate to the lower steps 14A where the pressure caused by water weight is the greatest. Thus, as shown in FIGS. 4 and 6B, the first cross-beams 50 are proximate to both edges 16, 18 of the upper step 14C and to the running edge 18 of the middle step 14B. Additionally, the second cross-beams 60 are proximate to both edges 16, 18 of the lower step 14A and to the rising edge 16 of the middle step 14B. The notches 52, 62 of each cross-beam 50, 60 fit into and interweave with the notches 24, 26 of the web 12, which provides additional stability to the staircase 10. It should be understood, however, that notches 52, 62 on the cross-beams 50, 60 are not necessary. In other embodiments, the cross-beams 50, 60 do not have notches (like the mounting cross-beam 40).
FIG. 3 shows an embodiment of a cover piece 70 that may be used to cover the exposed cross-beams 50, 60 and the edges of the web 12 (as shown in FIGS. 5 and 6). The cover piece 70 may be provided with pre-drilled apertures 72 to receive fasteners to secure the cover piece 70 to the assembly. It should be understood that the pre-drilled apertures 72 are not necessary, however, and in other embodiments the cover piece 70 is coupled to the assembly by other means. In certain embodiments, at least one of the long edges of the cover piece 70 may be provided with an undercut or a tongue and groove such that two adjoining cover pieces 70 (for example, at the apex of the steps 14A-C in FIG. 6B) fit together in order to avoid exposed edges. If desired, the length of each cover piece 70 may be slightly greater than the length of the assembled webs 12 (shown in FIG. 5) such that the cover piece 70 extends beyond the overhangs 53, 63 of the cross-beams 50, 60.
Other embodiments of staircases (not shown) may not include cover pieces 70. Instead, there may be provided cross-beams that are “L” or “T” shaped, having at least one vertical face and at least one horizontal face. The vertical face of the cross-beam may have notches to interweave with the notches of the web, and the horizontal face of the cross-beam may contact the top edges of the web to thus provide a smooth and continuous surface over the web. In this way, “L” or “T” shaped cross-beams may provide an alternate embodiment for a separate cover piece 70.
In another embodiment (such as in FIGS. 17E and F), a staircase may be provided with a bench, which resembles an extended step. The bench provides another area for users to sit or stand on, without blocking the rest of the steps.
FIGS. 4 and 5 are exploded views showing how a staircase 10 according to certain embodiments may be assembled, and FIG. 6 shows an assembled staircase 10. The staircase 10 shown in FIGS. 4-6 has three webs 12 that are spaced approximately equally from one another. The number of and spacing of the webs 12 may be influenced, at least in part, by the number of and spacing of the notches 52, 62 along the cross-beams 50, 60. Specifically, there are three notches 52, 62 on each cross-beam 50, 60 (respectively) to receive a portion of each of the three webs 12. But the number of webs 12 is non-limiting, and other embodiments of a staircase 10 may have fewer or more webs 12. For example, another embodiment may have five webs 12 and five corresponding notches 52, 62 along each cross-beam 50, 60. (Thus, the staircase 110 shown in FIG. 7B has four webs.) In other embodiments the number of notches 52, 62 and webs 12 are not necessarily equal. For example, there may be ten notches 52, 62 along each cross-beam 50, 60, but only four webs 12. (In other words, some of the notches 52, 62 may go un-used.) The total length of the staircase 10 may influence the number of webs 12. For example, longer staircases 10 may have more webs 12 than shorter staircases 10. Other design considerations may also influence the number of webs 12.
FIG. 4 shows a liner retention strip 38 that may optionally be received within the liner retention notch 23 of each web 12. The liner retention strip 38 may be a strip of extruded PVC, and may contain grooves to receive a vinyl liner (not shown) that may be used to cover the staircase 10 if the staircase 10 is installed in a vinyl liner-type of swimming pool. It should be understood that the liner retention strip 38 is not necessary, however.
FIG. 4 shows an exploded view of the cross-beams 50, 60 (and mounting beam 40). It does not matter whether the first cross-beams 50 or the second cross-beams 60 are assembled first. The first cross-beams 50 are received within the notches 24, 26 such that notches 52 fit into and interweave with the notches 24, 26 on the web 12. Similarly, the second cross-beams 60 are received within the notches 24, 26 such that the notches 62 fit into and interweave with the notches 24, 26 on the web 12. As shown in FIG. 4, overhangs 53, 63 may protrude on one side of the webs 12. As shown in FIGS. 5 and 6B, the tops of the cross-beams 50, 60 may be flush with the rising edge 16 and running edge 18 of the steps 14, respectively. If desired, the second cross-beam 60 (which may be taller than the first cross-beam 50) may be provided with longer notches 62 such that the second cross-beam 60 sits flush with the edges 16, 18 of the web 12. If desired, adhesive or mechanical fasteners may be used to further secure the cross-beams 50, 60 to the web 12.
Additionally, first cross-beams 50 may be received within the cut-outs 30 such that the notches 52 on cross beams 50 fit into and interweave with notches 32 of cut-outs 30. Moreover, cross beams 40, 50 may be assembled along the back edges 20 of the webs 12. In the embodiment shown in FIG. 4, two mounting cross-beams 40 are received within the first notches 34 such that the mounting cross-beams 40 are approximately parallel to the back edge 20. The mounting cross-beams 40 provide a means to mount the staircase 10 to the pool wall 100. Additionally, a first cross-beam 50 is received within the second notch 36 such that it is approximately perpendicular to the back edge 20, which provides structural stability proximate to the back edge 20 of the webs 12.
FIG. 5 shows an exploded view of six cover pieces 70 that may be coupled to the assembly such that they contact the rising edge 16 and running edge 18 of each of the three steps 14. The cover pieces 70 make a smooth and continuous surface for people to step on, and for a vinyl liner to cover (as shown in FIG. 6). As shown in FIG. 6B, the cover pieces 70 that are proximate to the rising edge 16 of the middle and upper steps 14B, 14C may be received within the liner retention notch 23. The cover pieces 70 may be coupled to the assembly with fasteners, adhesive, welding, or any other means known to one of skill in the art. In certain embodiments, the cover pieces 70 are coupled directly to the edges 16, 18 of the steps, but in other embodiments, the cover pieces 70 are coupled to the edges of the cross-beams 50, 60. Finally, in embodiments wherein the cover pieces 70 are provided with an undercut, two adjoining cover pieces 70 (for example, at the apex of the steps 14A-C) fit together in order to avoid exposed edges.
In certain embodiments, it may be desirable to couple two staircases together. Different types of staircases (for example, staircase 10, 110, 150) may be coupled together in any order or combination. FIGS. 17A-F show certain non-limiting examples of how staircases may be coupled together. FIG. 17A shows two straight staircases coupled together, where as FIGS. 17B and 17D shows two curved staircases coupled together. FIG. 17C shows a straight staircase coupled between two curved staircases. FIGS. 17E and F show staircases having benches coupled together. Any combination is within the scope of the invention. If desired, the outermost webs of each staircase may have the same shape, such that the ends “match” when coupled. Thus, embodiments provided herein are modular in that the staircases may be interchanged to fit swimming pools having different shapes and sizes.
The webs 12 may be provided with apertures to receive a bolt or other fastener to couple the two staircases 10 together. When two staircases 10 are coupled together, there may be a gap between the webs 12 of adjoining staircases 10 caused by overhangs 53, 63. To conceal the gap, the cover pieces 70 may be longer than the overall length of the assembled webs 12 such that the cover pieces extend beyond the overhangs 53, 63. In this way, the longer cover pieces 70 conceal the gap between adjoining staircases 10. The gap may also create instability when two staircases 10 are coupled together. Thus, embodiments may be provided with a plurality of spacing pieces 80 coupled to the two outermost webs 12 of each staircase 10. An aperture may be provided in the center of each spacing piece 80 to receive a bolt or other fastener to couple the two staircases 10 together. The spacing piece 80 has a thickness that fills the gap created proximate to each coupling bolt, and thus, improves stability when two staircases 10 are coupled together. While the position of the spacing pieces 80 on the web 12 is not critical, in certain embodiments it may be desirable to position the spacing pieces 80 proximate to edges of the web (for example, at the apex of each step 14A-C, along bottom edge 22 or back edge 20) such that the spacing pieces 80 are easy to access when assembling the staircase 10. The spacing pieces 80 may be coupled to the web 12 with fasteners, adhesive, welding, or any other means known to one of skill in the art. Additionally, the spacing pieces 80 may be coupled to the web 12 either before or after the cross-beams are assembled.
FIGS. 6A and B show an assembled staircase 10 according to certain embodiments installed within a pool. The back edge 20 of the staircase 10 is proximate to the pool wall 100, and the bottom edge 22 is proximate to the pool floor 102. In this embodiment, the pool wall 100 is straight, without any curves. But in FIGS. 7A and 12A, the pool wall 112 is curved, and thus, embodiments of staircases 110, 150 are modified slightly from staircase 10 to accommodate the curved pool wall 112. The basic construction of the staircases 110, 150 is similar to that of staircase 10 in that each staircase is constructed from webs, cross-beams, and cover sheets. Thus, the construction of the curved staircases 110, 150 are only discussed to the extent that they differ from that of staircase 10.
FIGS. 7A and B show a staircase 110 that may be installed against a curved wall 112 of a pool. Staircase 110 has three steps 122, 124, 126, wherein each step is progressively smaller towards the top of the staircase 110. As shown in FIGS. 8 and 9, the staircase 110 includes four webs 114, 116, 118, 120, each of which is shaped differently to accommodate the different shapes of the steps 122, 124, 126. Web 114 may have the same size and shape of web 12 of staircase 10 to facilitate coupling of the staircases 10, 110. If desired, at least some of the webs (referred to collectively as web 114 for ease of reference) may be provided with handle cut-outs 136 to allow a user to easily grasp the web 114 (or assembled staircase 110). The webs 114 may also be provided with cut-outs 138 to receive cross-beams 134. FIG. 10 shows a back-piece 132 and various cross-beams 134 that couple to the webs 114. If desired, cross-beams 134 that are assembled proximate to step 122 may have different dimensions than those that are assembled proximate to step 126, such as to provide greater strength and stability near the bottom of the staircase 110 (as described above with respect to cross-beams 50, 60 in FIGS. 2B, 2C). FIG. 11 shows riser cover pieces 128 that are generally rectangular shaped, and runner cross pieces 130 that have at least one curved edge. In general, the shapes and/or dimensions of the respective components may vary to accommodate the curve of wall 112. Despite these differences, the components of staircase 110 are assembled in generally the same matter as in staircase 10; specifically, the webs 114 have notches that receive cross-beams 134 (and back-piece 132), and cover pieces 128, 130 are then coupled to the assembly. The curved staircase 110 may be coupled to other staircases as described above, and thus, may be provided with spacing pieces 80 to receive bolts or other fasteners to couple one staircase to another.
FIGS. 12A and B show yet another staircase 150 that may be installed against a curved wall 112 of a pool. Staircase 150 also has three steps that are progressively smaller towards the top of the staircase 150. As shown in FIG. 13, the staircase 150 includes two webs 156, 158 that may be shaped similarly to one another (as shown in FIG. 14). The outermost web 158 may have the same size and shape of web 12 of staircase 10 (or web 114 of staircase 110) to facilitate coupling of the staircases. Additionally, the staircase 150 may include back-piece 154. If desired, at least one of the webs 156, 158 may be provided with handle cut-outs 166 to allow a user to easily grasp the web 156, 158 (or assembled staircase 150). The webs 156, 158 and/or back-piece 154 may also be provided with cut-outs 168 to receive cross-beams 164. FIG. 15 shows riser cover pieces 160 that are generally rectangular shaped, and runner cross pieces 162 that have at least one curved edge. FIG. 16 shows various cross-beams 164 that couple to the webs 156, 158 and/or back-piece 154. If desired, cross-beams 164 that are assembled proximate to the bottom of the staircase 150 may have different dimensions than those that are assembled proximate to the top of the staircase 150, such as to provide greater strength and stability near the bottom of the staircase 150. In general, the shapes and/or dimensions of the respective components may vary to accommodate the curve of wall 112. Despite these differences, the components of staircase 150 are assembled in generally the same matter as in staircase 10 and 110; specifically, the webs 156, 158 and back-piece 154 have notches that receive cross-beams 164, and cover pieces 160, 162 are then coupled to the assembly. The curved staircase 150 may be coupled to other staircases as described above, and thus, may be provided with spacing pieces 80 to receive bolts or other fasteners to couple one staircase to another.
Any of the components of the staircases 10, 110, 150 described herein (for example, webs, cross-beams, reinforcement squares, cover pieces, and back-piece) may be made from sheets of non-corrosive plastic, such as a polymer. For ease of reference, this disclosure references staircase 10, although it should be understood that the disclosure may apply equally to staircase 110, 150. In one specific non-limiting embodiment, the components are made from sheets of acrylonitrile butadiene styrene (ABS) plastic that is 0.4 inch thick, but other thicknesses and types of plastics may be used. In other embodiments, the components are made from other materials, such as wood or metal. The shapes of the various components may be cut out using any type of cutting instrument, such as scissors, a knife or saw, or lasers.
The staircases 10 may be fastened to the walls 100, 112 of the pool with fasteners, adhesive, or other means known to one of skill in the art. If the staircase 10 is installed in a vinyl liner-type pool, then if desired, the staircase 10 may be covered with a vinyl sheet to match the rest of the vinyl liner-type pool. Non-corrosive mechanical fasteners and/or a liner retention strip 38 may be used to couple the vinyl sheet to the staircase 10. But it is not necessary to cover the staircase 10 with a vinyl sheet (for example, if the staircase is installed in a concrete or gunite pool). Embodiments of staircases 10 described herein may support and withstand forces applied by both the water contained within the pool and from users sitting or standing on the staircase 10. Specifically, as shown in FIG. 6B, the water has a depth D within the pool. The waterline 104 is located above the top step 14. Each successive step 14 closer to the floor 102 is exposed to more force from the water weight. But the staircases 10 described herein can withstand such force (and force exerted by users). Specifically, at least one of the use of multiple webs or the interweaving notches of cross-beams and webs may help the staircases withstand forces caused by water weight and/or users.
The foregoing is provided for purposes of illustration and disclosure of embodiments of the invention. It will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, it should be understood that the present disclosure has been presented for purposes of example rather than limitation, and does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art.
Patent Application
20120167494
