Escalator Step with Dual-Radius Seating Element

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Solution Overview

Problem

The gap between escalator steps is not constant, varying with the height difference between adjacent steps, which can lead to safety hazards and increased risk of objects or fingers getting trapped, especially during transitions from inclined to horizontal sections.

Innovation Solution

A step design with a skeletal sheet metal construction featuring a setting element with an arcuate profile and deep-drawn webs and grooves, ensuring a consistently small step gap regardless of the height difference, achieved through the use of thin deep-drawn sheet metal with specific radii and production processes like deep-drawing and roll forming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the setting element is designed flat to simplify production, then manufacturing complexity is reduced, but the step gap widens during transitions creating safety hazards

Engineering Contradiction:
Improveproduction simplicityVSAvoidsafety
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The setting element is designed with an arc-shaped cross-section instead of being flat. This curvature allows the step to maintain a consistently small gap between adjacent steps during transitions from inclined to horizontal sections, preventing safety hazards while remaining manufacturable through deep-drawing processes

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Strength

If thicker sheet metal is used to increase structural strength, then load-bearing capacity improves, but weight increases and production complexity increases

Engineering Contradiction:
Improveload-bearing capacityVSAvoidstep weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The step structure uses thin sheet metal (1.5-3.0 mm) with a deep-drawn web/groove profile that provides sufficient structural strength and load-bearing capacity while minimizing weight. The web/groove configuration provides rigidity without requiring thick material

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The setting element is divided into multiple webs and grooves, creating a segmented structure that provides both strength through distribution of loads and weight reduction through material optimization. The web/groove profile achieves structural integrity with thin sheet metal

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If the setting element has constant cross-section to simplify production, then manufacturing is easier, but the step gap cannot be kept constant during height transitions

Engineering Contradiction:
Improveproduction simplicityVSAvoidstep gap consistency
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The setting element transitions from a constant cross-section design to a variable cross-section design where the arc-shaped configuration changes along the direction of travel. This dynamic geometry allows the step gap to remain constant during height transitions while being produced through continuous deep-drawing and roll forming processes

Inventive Principle:
Principle #15Dynamics

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

This design maintains a constant step gap size, reducing accident risks and enhancing safety while providing weight and cost savings, meeting load test standards and allowing for efficient production without additional complexity, with the added benefit of reduced drive power requirements for the escalator.

Implementation Method 1

the setting element having a web/groove profile with webs and grooves made from deep-drawn sheet metal

Methodology Applied
Scientific EffectDeep-drawing: Cold-forming

Data Source

PatentEP2200923B1Step for a moving staircase or pallet for and moving staircase with such a step
Publication Date: 2016.07.06 INVENTIO AG
  • EP2200923B1 patent drawingFigure 1
  • EP2200923B1 patent drawingFigure 2
  • EP2200923B1 patent drawingFigure 3

AI summary

The step (1) comprises cheeks (5) which are manufactured from deep drawing sheet metal, and a tread element (22) and a deep drawn seating element (24). The arc (BO1) of the seating element (24) follows a first radius (R1) in the upper region and a second radius (R2) in the lower region, wherein the second radius (R2) is somewhat smaller than the first radius (R1). The sheet (BO1) of the seating element (24) merges smoothly at the line (ÜR) from one radius into the other radius. By way of the two radii (R1, R2), the size of the step gap between the tread element (22) and the seating element (24) of the adjacent step is independent of the position of the step gap; the step gap always remains very small, for example smaller than 2.8 mm. As a result, the risk of clothing items, sharp objects, shoes, children's fingers and so on getting jammed is reduced considerably.