Telescopic A-Frame Ladder With Stand-Off Wall Support

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing A-frame ladders are not easy and safe to handle, as they require complex transitions between configurations and lack stability when set up against a wall.

Innovation Solution

An A-frame ladder design with telescopic ladder assemblies, a stand-off device, and a lock assembly that allows for easy conversion between inverted V-shaped and straight configurations without partial collapse, ensuring stability by supporting one end on the floor and the other on a wall.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the A-frame ladder is designed with two telescopic ladder assemblies that are folded onto each other in the straight configuration, then the ladder can be set up against a wall, but the ladder assemblies cannot both be in the extended configuration, requiring partial collapse which reduces stability

Engineering Contradiction:
Improveability to set up against wallVSAvoidstability when extended
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces asymmetry in the hinge connection between the two ladder assemblies. The first ladder assembly is hingedly connected to the second ladder assembly at a hinge axis that is offset from the centerline of the second assembly. This asymmetric hinge positioning allows the first assembly to be fully extended while the second assembly is partially collapsed, yet both can remain in their extended configurations simultaneously when set up against a wall, resolving the contradiction between adaptability and reliability

Inventive Principle:
Principle #4Asymmetry

2Reliability

If the hinge axis is positioned closer to the top rung of the ladder assembly, then the ladder can be set up against a wall with both assemblies extended, but the distance between the hinge axis and the top rung increases, affecting the compactness

Engineering Contradiction:
Improvestability when both assemblies extendedVSAvoiddistance from hinge axis to top rung
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent optimizes the hinge axis position by changing the geometric parameters of the connection. The hinge axis is positioned at a specific distance from the top rung that balances two requirements: it is far enough to allow both ladder assemblies to be fully extended when set up against a wall, yet close enough to maintain compactness when folded. This parameter optimization resolves the contradiction between reliability and volume

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the ladder requires complex unlocking steps to collapse the second ladder assembly, then the transition between configurations is difficult, but the ladder can maintain stability in each configuration

Engineering Contradiction:
Improvestability in each configurationVSAvoidease of configuration transition
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent implements a self-service mechanism through the telescopic connection between the two ladder assemblies. The first ladder assembly telescopically connects to the second assembly, allowing the second assembly to be easily collapsed and repositioned without complex unlocking steps. The telescopic design inherently provides stability when extended while enabling easy operation during transitions, resolving the contradiction between reliability and ease of operation

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4405557B1Portable ladder with a stand off device
Publication Date: 2025.09.17 LAMPE HLDG
  • EP4405557B1 patent drawingFigure 1~2
  • EP4405557B1 patent drawingFigure 3~4
  • EP4405557B1 patent drawingFigure 5~6

AI summary

The invention relates to an A-frame ladder, comprising a first telescopic ladder assembly and a second telescopic ladder assembly that are hingedly connected such that the second ladder assembly is pivotal about a hinge axis relative to the first ladder assembly between a straight configuration and an A- configuration. The second ladder assembly, at a top end thereof, is hingedly connected to stand off arms, such that the hinge axis is in line with the stile members of the second ladder assembly, and the hinge axis, in a longitudinal direction of the ladder assemblies, is spaced relative to a top rung of the first ladder assembly at a first pivot distance, and is spaced relative to a top rung of the second ladder assembly at a second pivot distance, wherein the second pivot distance is smaller than the first pivot distance.