Sewage Ladder Plastic Coated Treads for Slip Prevention
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Solution Overview
Problem
Existing ladders for accessing sewage shafts, made of corrosion-resistant metal, have slippery tread areas that do not effectively prevent slipping, especially in moist environments, posing a safety risk during maintenance and repairs.
Innovation Solution
The ladder features a plastic coating on the tread elements made of polypropylene, applied via injection molding, which increases friction and prevents slipping, while maintaining the durability and stability of the corrosion-resistant metal structure, with the coating being absent in areas for fastening to ensure structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the tread elements are made of metal, then durability is improved, but slipping resistance deteriorates in damp environments
Solution Approach 1:
The patent combines metal tread elements with a plastic coating to create a composite structure. The metal base provides durability and corrosion resistance, while the plastic coating layer provides enhanced friction and slipping resistance in damp environments. This composite approach allows both materials to contribute their respective advantages simultaneously.
Solution Approach 2:
The plastic coating is applied specifically to the tread surfaces where friction is needed, while leaving the metal exposed in joining areas for attachment. This localized application ensures that each area of the tread element has the appropriate material properties for its specific function.
2Reliability
If a plastic coating is applied to the tread elements, then slipping resistance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent replaces traditional mechanical attachment methods with injection molding technology. The plastic coating is applied directly to the metal tread elements through injection molding, creating a permanent bond without requiring additional fasteners or assembly steps. This substitution simplifies the overall manufacturing process despite adding a coating step.
Solution Approach 2:
The patent merges the coating application process with the manufacturing process itself. By using injection molding to apply the plastic coating, the coating step becomes an integrated part of production rather than a separate post-processing operation, reducing overall manufacturing complexity.
3Reliability
If the plastic coating covers the entire tread element, then slipping resistance is maximized, but structural integrity deteriorates
Solution Approach 1:
The patent applies the plastic coating only to specific surfaces of the tread elements where friction is required, while deliberately leaving the joining areas exposed. This ensures that the metal-to-metal contact in joining areas maintains maximum structural integrity and bonding strength, while the coated surfaces provide enhanced slipping resistance.
Solution Approach 2:
The patent extracts the plastic coating from the joining areas, removing it only where it would interfere with structural integrity. This selective removal allows the coating to provide its friction-enhancing function wherever needed while preserving the metal's bonding capability in critical attachment zones.
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 plastic coating significantly reduces slipping on the ladder, even in damp conditions, ensuring safe and comfortable access to sewage shafts without compromising the ladder's stability or longevity.
Implementation Method 1
the tread areas of the tread elements can easily exhibit greater friction than metal surfaces, particularly in damp environments, so that slipping from the tread elements can be effectively prevented
Implementation Method 2
Such a plastic coating can be easily applied to the metal tread elements using injection molding
Implementation Method 3
The tread elements are welded to the stiles via two fastening points each
Data Source
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AI summary
The invention relates to a ladder (1) for accessing shafts, in particular sewage shafts, with two vertical stiles (2) running parallel to each other and made of a corrosion-resistant, weldable metal, and a plurality of vertically arranged steps (3) formed of a corrosion-resistant, weldable metal, wherein the steps (3) are welded to the stiles (2) via two fastening points (4) and connect the two stiles (2) to each other, wherein the steps (3) each have a horizontal tread area (5) for stepping onto the steps (3), wherein at least the tread area (5) of the steps (3) has a plastic coating (6) over the corrosion-resistant, weldable metal of the steps (3), and a connection system (16) for connecting two such ladders (1).