Wedge Tread Stair Box with Removable Covers
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Solution Overview
Problem
Traditional staircases built on-site for construction are unstable and unsafe, while prefabricated ones face issues of damage, wear, and tear, and require premature installation of decorative materials, leading to increased costs and construction time.
Innovation Solution
A stair box system with a core structure of stringers, treads, and risers featuring discontinuous mortises, beveled surfaces, and removable covers that allow for easy assembly and replacement, reducing the need for wedges and shims, and enabling the use of separate structures for attaching sheet rock without damaging the stair box.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If temporary staircases are built on site to meet OSHA requirements and provide worker access, then worker access during construction is enabled, but the staircases become unstable and unsafe
Solution Approach 1:
The stair box is divided into modular components (stringers, treads, risers, nosings) that can be pre-assembled and then installed as a complete unit. This segmentation allows the staircase to be manufactured with precise fit-and-finish connections in a controlled environment, ensuring stability while providing worker access during construction.
2Reliability
If prefabricated stair boxes are installed early to provide stable staircases, then staircase stability is improved, but the stair boxes are exposed to weather and wear during construction
Solution Approach 1:
The stair box is pre-assembled with all finishings (carpet, hardwood, paint) applied in advance during manufacturing. This preliminary action protects the finishings from weather exposure and wear during construction, as the complete stair box is then enclosed within the building structure. The pre-applied finishings eliminate the need for post-construction refinishing work.
3Shape
If decorative materials are installed on stair boxes early to match flooring, then aesthetic matching is achieved, but the materials require sanding and refinishing after sheet rock installation
Solution Approach 1:
All decorative materials (carpet, hardwood flooring, paint) are pre-installed on the stair box components during the manufacturing process, long before the stair box is installed in the building. This preliminary action ensures aesthetic matching with the building's flooring and eliminates the need for time-consuming sanding and refinishing work after sheet rock installation, as the finishings are already protected and finalized.
4Strength
If traditional mortises are cut into stringers to engage treads and risers, then structural connection is achieved, but lateral movement and play remain in the finished stair box
Solution Approach 1:
The patent employs asymmetric wedge-shaped components inserted into the stair box structure. These wedges are positioned at specific locations to provide lateral bracing and eliminate play between the stringers, treads, and risers. The asymmetric placement and shape of the wedges create friction and mechanical interference that prevent lateral movement, complementing the traditional mortise connections.
5Stability of the object's composition
If additional wood pieces are wedged into place to stabilize the stair box, then lateral movement is reduced, but squeaking noises occur when weight is applied
Solution Approach 1:
The patent changes the material parameters and surface properties of the wedge components. Instead of using traditional rough-surfaced wood wedges, the invention employs wedges with smooth, treated surfaces or specialized coatings that reduce friction and eliminate squeaking. The wedge material composition is optimized to provide both lateral stabilization and noise-free operation under load.
Data Source
AI summary
A stair box system made of a stair box core, stringers, risers and treads. The inner surfaces of the stringers have a discontinuous series of mortises positioned to engage only with the treads. Each tread is beveled from the front to back surfaces and each of the riser is beveled from the top to the bottom surface. Each tread features one or more notches cut into its back surface and each riser includes a complementary hook cut into its bottom surface. The hooks on the risers engage the notches on the treads forming an open-faced channel. Removable covers fit over the treads of the stair box core. These covers protect the stair box core and/or they feature decorative building materials like hardwood or tile. The system allows the user to upgrade their stairs by replacing the covers with covers featuring a different finished surface.