Retractable Step Lever Mechanism with Modular Crosspiece Assembly

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Solution Overview

Problem

Existing retractable steps for recreational vehicles lack versatility in size configuration and efficient assembly, often resulting in cumbersome designs that are either too heavy or difficult to assemble.

Innovation Solution

A retractable step design utilizing aluminum crosspieces and steel screw insertion plates, connected via hollow crosspieces with opposed slots and screws, allowing for efficient assembly and size customization without significant weight increase, and controlled by an electric motor for easy operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional retractable step designs are used, then the step can be mounted on recreational vehicles, but the assembly process becomes cumbersome and the design lacks versatility in size configuration

Engineering Contradiction:
Improvesize configuration versatilityVSAvoidassembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The retractable step is divided into modular components including multiple levers (front and rear pairs), crosspieces, screw means, and fixing structures. Each component can be independently manufactured and assembled, allowing for easy configuration changes and simplifying the overall assembly process while maintaining size versatility.

Inventive Principle:
Principle #1Segmentation

2Strength

If heavy materials are used to ensure structural strength, then the step can support required loads, but the overall weight of the step increases substantially

Engineering Contradiction:
Improvestructural strengthVSAvoidstep weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The step structure utilizes a composite construction combining aluminum crosspieces with steel screw insertion plates. The aluminum provides lightweight structural support while the steel plates ensure strong fastening points. This material combination achieves the required structural strength without substantially increasing the overall weight of the step assembly.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If standardized components are used for manufacturing, then production efficiency improves, but the ability to customize different sizes is reduced

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidsize customization
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The screw insertion plates are designed with multiple through-holes arranged in different patterns, allowing the same plate component to accommodate various lever positions and step configurations. This universal design enables customization of different step sizes using the same standardized components, maintaining both manufacturing efficiency and size versatility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3604037B1Retractable step
Publication Date: 2020.05.13 LCI ITALY SRL
  • EP3604037B1 patent drawingFigure 1
  • EP3604037B1 patent drawingFigure 2
  • EP3604037B1 patent drawingFigure 3A

AI summary

Retractable step applicable to recreational vehicles, comprising a step (1), a plurality of levers (10, 11) each of which has a front end (101, 111) hinged on one side of the step tread (1), and a fixing structure (2) to which a rear end (102, 112) of each of said levers (10, 11) is hinged, wherein said levers are divided between front levers (10) and rear levers (11) in relation to their position with respect to the step tread (1), wherein a front crosspiece (3) connects the front levers (10) with each other, wherein a rear crosspiece (4) connects the rear levers (11) with each other, wherein first screw means (6) constrain the front levers (10) to the front crosspiece (3), and wherein second screw means (7) constrain the rear levers (11) to the rear crosspiece (4). Each of said crosspieces (3, 4) is hollow and has a pair of opposing slots (S) at a predetermined distance from each of its side ends. In each of said slots (S) is inserted a plate (5) having a predetermined number of through holes (50). Each plate (5) has a surface (51) insertable in a slot (S). Said holes (50) are formed on said surface (51) and said screw means (6, 7) engage said holes (50).