Lift Truck Mast Segment Chain Attachment Integration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing mast segment designs for lift-trucks suffer from material fatigue in welds due to repeated lifting and lowering operations, leading to potential cracks and increased downtime for maintenance.

Innovation Solution

The mast segment design integrates the chain attachments directly with the bottom beam, eliminating welds in the force path and reducing the risk of material fatigue by ensuring the force from the load travels directly through the beam material to the lifting chains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If chain attachments are welded to vertical beams of the mast segment, then the mast segment can be assembled with separate components, but the welds are subject to material fatigue from repeated lifting operations leading to cracks and maintenance downtime

Engineering Contradiction:
Improveease of assemblyVSAvoidreliability of welds
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The chain attachment is merged with the bottom beam to form a single integral component. This eliminates the weld between the chain attachment and vertical beam that was previously subject to fatigue from lifting operations. The force path now travels directly through the integral structure without passing through a welded joint, resolving the contradiction by combining components to eliminate the weak welded connection while maintaining ease of manufacture through the integral design.

Inventive Principle:
Principle #5Merging (Combining)

2Device complexity

If chain attachments are welded to vertical beams, then separate components can be manufactured and assembled, but the force path passes through welds causing fatigue and potential failure

Engineering Contradiction:
Improvestructural complexityVSAvoidstrength of welds
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The chain attachment and bottom beam are merged into one integral component, eliminating the welded joint in the force path. This resolves the contradiction by removing the weak welded connection while the overall structural complexity remains manageable through the streamlined integral design.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the bottom beam is designed as an integral structure with chain attachments, then material fatigue in welds is eliminated, but manufacturing the integral structure may be more complex

Engineering Contradiction:
Improvereliability of mast segmentVSAvoidease of manufacturing integral structure
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The bottom beam and chain attachments are merged into an integral structure where the chain attachment is formed as part of the bottom beam itself. This eliminates welds in the critical force path, significantly improving reliability. The manufacturing complexity is managed through the integral design that eliminates the need for separate welding operations in the high-stress areas.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3178775B1Mast segment for a lift-truck and a lift-truck comprising a mast segment
Publication Date: 2021.10.27 TOYOTA MATERIAL HANDLING MFG SWEDEN
  • EP3178775B1 patent drawingFigure 1~2
  • EP3178775B1 patent drawingFigure 3~4
  • EP3178775B1 patent drawingFigure 5~6

AI summary

A mast segment (130) for an extendable mast (110) of a lift-truck (1), said mast segment (130) comprising: - a first vertical beam (131) having an upper end (132) and a lower end (133) and a second vertical beam (134) having an upper end (135) and a lower end (136); - a first lifting chain attachment (220) and a second lifting chain attachment (230) for holding a respective end (51, 52) of a first and second lifting chain (50, 52) for raising or lowering the mast segment (130); - a bottom beam (200) interconnecting the lower end (133) of the first vertical beam (131) and the lower end (136) of the second vertical beam (134); wherein the first lifting chain attachment (220) and the second lifting chain attachment (230) are integral with the bottom beam (200).