Escalator Support Wall Element Bending Moment Distribution
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Solution Overview
Problem
Existing structural designs for lifting staircases and driving gowns face challenges in providing cost-effective support while ensuring structural rigidity and safety, particularly under high bending moments, often resulting in heavy materials and increased costs due to extensive welding or complex component compositions.
Innovation Solution
A supporting change element with a side wall part made from folded sheet metal, featuring a top belt and fastening flanges that enclose the upper belt to distribute bending moments, and a C-shaped cross-section with recesses and diagonal struts forming a half-timbered structure for enhanced stiffness, allowing for lightweight and cost-effective construction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of stationary object
If sheet metal is used for supporting wall elements to reduce weight and cost, then material and transport costs are reduced, but the structure lacks sufficient rigidity to resist high bending moments from balustrades
Solution Approach 1:
The supporting wall element is divided into distinct functional zones: a top chord region for bending moment resistance, a side wall part for structural continuity, and a fastening flange for balustrade attachment. This segmentation allows each zone to be optimized for its specific function while maintaining overall structural integrity using lightweight sheet metal.
Solution Approach 2:
The invention transitions from traditional three-dimensional structural shapes to a two-dimensional sheet metal approach with strategic folding. The top chord is formed by folding the sheet metal edge, creating a stiffened section that resists bending moments through geometric configuration rather than bulky material, effectively using the third dimension (folding angle) to enhance rigidity without increasing mass.
2Strength
If a square tubular profile is welded to stiffen the upper chord against buckling, then buckling stiffness and torsional rigidity are improved, but manufacturing complexity and cost increase due to extensive welding
Solution Approach 1:
The invention extracts the essential stiffening function from the complex welded tubular profile and implements it through a simpler sheet metal folding operation. The folded top chord provides the necessary buckling resistance through its geometric configuration, eliminating the need for additional welded components while maintaining manufacturing simplicity.
Solution Approach 2:
The invention replaces expensive, complex welded tubular profiles with a simple folded sheet metal configuration that achieves the same stiffening effect. This approach uses inexpensive sheet metal and simple folding operations instead of costly welding processes, making the solution both economically and manufacturally superior.
3Ease of manufacture
If sheet metal edges are bent to achieve buckling stiffness, then manufacturing cost is reduced compared to welding, but torsional stiffness is compromised when high bending moments cause the bend to deform upward
Solution Approach 1:
The top chord is pre-folded during manufacturing to create a permanent stiffened configuration that resists both buckling and torsional deformation. This preliminary folding action establishes the geometric stiffness needed to withstand service loads, preventing the edge from deforming upward under bending moments and maintaining torsional stiffness throughout the structure's lifecycle.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides a lightweight, cost-effective structural support that effectively distributes bending moments, reducing material costs and maintaining structural integrity, facilitating easier assembly and maintenance.
Implementation Method 1
a top chord (69) formed by folding at a first longitudinal edge (47) of the side wall part (67)
Implementation Method 2
a central region (105) of the fastening flange (61), arranged between the first region (101) and the second region (103), at least partially enclosing the section (107) of the top chord (69) present in this region (105)
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a support wall element (63, 65) of a support structure (11) of an escalator (1) or of a moving walkway. This comprises a side wall part (67) which is machined in one piece out of a metal sheet, an upper chord (69) being formed on a first longitudinal edge (47) of the side wall (67) by bending and a lower chord (71) being formed on a second longitudinal edge (49) of the side wall (67) opposite the first longitudinal edge (47) by bending, and a side wall (73) of the side wall part (67) extending between the upper chord (69) and the lower chord (71). The support wall element (63, 65) also has at least one fastening flange (61) for fastening balustrade components (53, 55, 57) of a balustrade (51), said fastening flange (61) being firmly connected to the side wall (73) of the side wall part (67), projecting over the upper chord (69) orthogonally to the longitudinal extent of said upper chord and at least partially surrounding the portion of the upper chord (69) present in this region (105).