BACKGROUND INFORMATION
Field of the Invention
The invention relates to stairs, and in particular, stairs designed for exterior locations such as for use with docks or floats.
Discussion of Prior Art
Outdoor stairways are stairs that are made of sturdy weather-resistant materials and frequently designed and installed to, for example, access a water body from a dock or shore area.
Such stairs are frequently made from materials such as aluminum, and in order to have the necessary strength, many of the aluminum components are welded together, and when not welded together are often combined using numerous fasteners and connectors.
Unlike inside stairways, which are frequently similar in size and shape due to customary building techniques, these outdoor stairways may need to be of any number of different sizes to traverse whatever natural elements may separate the upper and lower landing areas.
These challenges, e.g. the need for a sturdy durable design that may need to span any reasonable distance across natural terrain, lead most manufactures to design stairways that have long, and thus heavy and cumbersome, segments that are largely welded together. Or, alternatively, they make smaller sections that require a great deal of effort to assemble on site.
Additionally, the desired angle of the steps on the stairway varies depending on the installation site, largely based on the angle of the stairway from the upper to lower landing areas.
What is needed, therefore, is a modular stairway that is comparatively easy to ship and assemble. What is further needed is a stairway having steps with an adjustable orientation so as to better suit the needs of the given location.
BRIEF SUMMARY OF THE INVENTION
The invention is an adjustable modular stairway that includes two or more segments that each include a welded stair tread frame that is configured to be bolted to its stringers, with a set of stringers in one segment adapted to be coupled to a set of stringers in another segment, and that includes adjustable end posts that are able to set the assembled stairway at various slopes.
The stringers are provided in sets, having stringer extrusions on a left side of the step and two or more support tubes on a right side of the step. In the primary embodiment, the support tubes are of a rectangular shape, requiring only a hole pattern and no welding to allow the steps to connect to the stringers by simply bolting the step to the stringers. The stringers are constructed in lengths to make up small segments of the stairway, for example, one, two and three step segments of stair that connect in a continuum nature for the creation of any length stair. The modular nature and convenient assembly enable economical shipping in the manner of a kit, and while professional installation may be available, the construction of the modular stair typically allows for do-it-yourself setup.
The stringers from the various segments are connected to one another with a splicing method, whereby splice bars or splice tubes that are slightly smaller in size than the stringers are inserted into each end of the adjacent side and secured in place by conventional fasteners. Support posts that include sockets, brackets, and posts are also provided and are typically connected to the outer side of the stringers and are configured to support the assembled segments with varying degrees of slope.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. The drawings are not drawn to scale.
FIG. 1 is a perspective view of a modular stairway with two segments separated, according to the invention.
FIG. 2 is a perspective view of the stairway in FIG. 1, the two segments fully assembled.
FIG. 3 is a perspective view of a 3-step, 2-segment stairway with one side assembled and one side separated.
FIG. 4 is a close-up view of an upper end of the stairway with the components separated prior to assembly.
FIG. 5 is a close-up view of the support assembly fully assembled.
FIG. 6 is a side view of an assembled stairway showing the steps set at a 16.6 degree orientation.
FIG. 7 is a side view of an assembled stairway showing the steps set at a 33.6 degree orientation.
FIG. 8 is a top view of an assembled step.
FIG. 9 is a perspective view of an assembled step.
FIG. 10 is a end view of an assembled step.
FIG. 11 is a side view of an assembled step.
FIG. 12 is a perspective exploded view of a step.
FIG. 13 is an end view of a step with the tread separated.
FIG. 14 is a perspective exploded view of a step.
FIG. 15 is a bottom view of a stringer.
FIG. 16 is a right side view of a stringer.
FIG. 17 is a top view of a stringer.
FIG. 18 is a left side view of a stringer.
FIG. 19 is a perspective view of a stringer.
FIG. 20 is an end view of a stringer.
FIG. 21 is a perspective view of a splice tube.
FIG. 22 is an end view of the splice tube.
FIG. 23 is a top view of the splice tube.
FIG. 24 is a side view of the splice tube.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described more fully in detail with reference to the accompanying drawings, in which the preferred embodiments of the invention are shown. This invention should not, however, be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be complete and will fully convey the scope of the invention to those skilled in the art.
FIGS. 1-24 illustrate a modular stairway 100 according to the invention. The stairway 100, in its unassembled form, is designed to be conveniently packaged for delivery to an installation site where it is easily assembled and may be set at various orientations depending on the needs of the site. The fully assembled stairway 100 is best shown in FIGS. 1-3 and 6-7.
While the stairway 100 may be configured in a number of different ways, it is likely to be comprised of various stair segments 10, as shown in FIGS. 1 and 2, with most segments including either one, two, or three steps 20. Each segment 10 includes a pair of stringers 40 that are configured to secure the steps 20 in the form of the stairway 100. Support posts 60 are attached to outer sides of the stringers 40, at various points including, at least, positions at or near the top and bottom of the stairway, to support the height of the stairway 100 above a surface area.
More specifically, as shown in FIG. 1, there is a first stringer 40A and a second stringer 40B that are configured to secure to a first side of each step 20 and a second side of each step 20, respectively. In the embodiment shown, and as further illustrated in FIGS. 15-20, each stringer 40 has an upper stringer extrusion 42 and a lower stringer extrusion 44, and each has a plurality of openings 45 to allow the steps 20 to be fastened to the stringers 40 with conventional fasteners F. The stringers 40 are approximately in the shape of a rectangular prism or cuboid, and include two ends 46, an inner side 48, an outer side 52, a top side 54 and a bottom side 56. The ends 46 are preferably hollow but in any event must allow for a connector to join multiple segments 10 together. For example, in the embodiment shown, the ends 46 are hollow so as to allow for a splice tube 80 to be inserted into the ends of two neighboring segments 10, where the splice bar 80 secures the two segments 10 together using conventional fasteners F.
Each step 20, best illustrated in FIGS. 8-14, includes a base 22 and a tread 24. The base 22 is likely to be a welded component comprised of a sturdy but lightweight material such as aluminum, and primarily be comprised of various support rods 26 that are, again, welded together, often creating welded joints WJ. In the embodiment shown, threaded rods 28 extend out for the sides of each base, which are configured to extend through the openings 45 in the stringers to secure the step to the stringers. More specifically, the internally threaded rods 28 are welded to the base plate 22 and fastened to the stringers with screws from the opposite wall of the respective stringer. This is advantageous as it makes the stairs more rigid than if they were fastened to just one wall of the stringers. Additionally, the rod and screw effectively utilize both walls of the stringer. Finally, this feature also contributes to the ease of assembly and is where and how the steps pivot on the stringers to accommodate varying slopes of the assembled stairway.
Each support post 60 includes a post 62 that is insertable into a socket 64 that is in turn coupled to a bracket 66, which connects to the stringer 40 with conventional fasteners F. The bracket pivots by using the same hole spacing as the steps 20.
In the embodiment shown, the splice tube 80, illustrated in FIGS. 21-24, is similar in shape to each of the lower stringer extrusion 44 and upper stringer extrusion 42, having a slightly smaller width and height so as to fit inside the hollow end 46 in a manner that does not allow for much movement, if any, while having a length that is substantially shorter than the upper stringer extrusion 42 and lower stringer extrusion 44 such that the splice bar only extends a short distance into the upper stringer extrusion 42 and lower stringer extrusion 44 relative to the overall length of the stringers. For example, the stringers 40 may have a length of 42 inches, and a hollow opening 46 that is approximately 2 inches in width and 2 inches high, while the splice tube 80 may have a width and a height of approximately 1.5 inches. Each splice tube 80 has a plurality of openings 82 that allow them to be secured to the upper stringer extrusion 42 or lower stringer extrusion 44 using conventional fasteners F. The splicing method that allows for modularity uses an aluminum tube within the stringers at the junction between two segments 10. On the end of each stringer 40 for each side of the junction, there is a set screw that holds the splice tube 80 in place inside the stringers. The splice bar 80 is also bolted in place at each end of a stringer 40. The bolts and set screws fasten on an axis perpendicular to each other.
Once the desired number of stair segments 10 are assembled, the stairway 100 may be set in position at various slopes. For example, by adjusting the height of an upper end of the stairway from roughly a 16.6 degree rise, which in the embodiment shown results in a elevation gain of four inches per step, to a roughly 33.6 degree rise resulting in a gap of 7.75 inches between steps.
FIGS. 6 and 7 illustrate the assembled stairway set at different slopes. To adjust to the desired angle of the stairway 100, the two support posts 60 on the top or bottom of the stairs should be put through the pipe brackets 66 and driven into a ground surface at a desired location. Then, the collective assembly of stringers 40 may be raised or lowered on the opposite end to acquire the desired angle and then a second set of support posts 62 may be driven into the pipe brackets 66 on this end and set screws tightened into the pipe bracket's socket 64 to secure the post 62. For example, the support posts 62 on the lower end of the stairway 100 may be fixed in position, while the fasteners on the steps 20 and the support posts 60 on the top end are fastened but remain loose such that the respective components may still move within the overall structure. The upper end may be adjusted upward or downward as desired to fit the chosen location. The upper posts 62 may then be driven into the ground and all fasteners tightened accordingly. Since the support posts 62 are driven vertically, the pipe brackets' bolt holes maintain a horizontal relationship with each other in which case the steps 20 do as well. Once the stairway 100 is set in the desired position with the desired slope, all fasteners are fully tightened.
It is understood that the embodiments described herein are merely illustrative of the present invention. Variations in the construction of the modular stairs may be contemplated by one skilled in the art without limiting the intended scope of the invention herein disclosed.
Patent Application
20250059770
