Engagement Chain Stiffness via Reinforcing Core

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Solution Overview

Problem

Conventional engagement chain type lifting apparatuses face challenges in increasing the stiffness of engagement chains, leading to reduced buckling strength and instability, especially as the lifting length of the lifting table extends, making it difficult to elevate driven bodies like lifting tables stably.

Innovation Solution

The engagement chain type advance/retract actuator incorporates a pair of engagement chains with hook-shaped inner and outer tooth plates that are meshed and reinforced with a prismatic reinforcing core inserted into a hollow part of the chain stiff part, enhancing stiffness and preventing bending, while a chain guide plate and chain supporting protruding portion further stabilize the system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the lifting length of the lifting table is extended, then the working range is increased, but the buckling strength of the engagement chains decreases inversely with the square of the length

Engineering Contradiction:
Improvelifting lengthVSAvoidbuckling strength
Core Design Contradiction:
Length of moving objectVSStrength

Solution Approach 1:

The engagement chain is divided into multiple link units (inner link units and outer link units) connected by coupling pins. This segmentation allows the chain to maintain structural integrity over extended lengths while distributing mechanical stresses across multiple connection points, preventing catastrophic failure and maintaining buckling resistance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The chain link units combine different structural elements (inner tooth plates, outer tooth plates, coupling pins, and bushing members) to create a composite structure. This composite design enhances the overall buckling strength by distributing loads across multiple material interfaces and structural components, allowing extended lifting lengths without proportional strength loss.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If the engagement chains are engaged and stiffened, then the stiffness is increased, but the chains become more difficult to disengage and furcate

Engineering Contradiction:
ImprovestiffnessVSAvoidease of disengagement
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The chain structure transitions dynamically between engaged and disengaged states. When engaged, the inner and outer link units form a stiff integrated structure for stable lifting. When disengaging, the coupling pins allow the link units to separate and furcate independently, enabling easy operation while maintaining stiffness during the lifting phase.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The coupling pins act as intermediaries between the inner link units and outer link units. These pins facilitate both the stiff engagement state (when connected) and the easy disengagement (when separated), mediating between the conflicting requirements of stiffness and operational ease through their removable connection mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If conventional mounting means are used to connect chains and lifting table, then the structure is simple, but the connecting part strength is insufficient and bolts rattle

Engineering Contradiction:
Improvestructural simplicityVSAvoidconnecting part strength
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The chain end portion mounting plate integrates multiple functions into a single component: it serves as both the chain termination structure and the lifting table mounting interface. This merging eliminates the need for separate mounting brackets and multiple bolt connections, reducing structural complexity while enhancing connecting strength through a unified load-path design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The mounting plate combines the chain attachment function with the table mounting function in a composite structural design. This integrated approach creates a stronger connecting part by distributing stresses across a larger, more rigid structure rather than relying on weak bolt-hole connections alone.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP2634455B1Engagement chain type device for forward and backward movement operation
Publication Date: 2020.03.18 TSUBAKIMOTO CHAIN CO
  • EP2634455B1 patent drawingFigure 1
  • EP2634455B1 patent drawingFigure 2
  • EP2634455B1 patent drawingFigure 3

AI summary

In order to stably drive a body to be driven such as a lifting table, an engagement chain type device (100) for forward and backward movement is configured in such a manner that a pair of engagement chains (110, 110) has rigid chain portions (110D). The rigid chain portions (110D) are configured in such a manner that, within a predetermined range from the front ends of the chains in the direction in which the pair of engagement chains (110, 110) is rigid, inner tooth plates (111) are constantly engaged with each other and outer tooth plates (112) are constantly engaged with each other. Square column-shaped reinforcement core members (140) fitted in the square column-shaped hollow sections (S) of the rigid chain portions (110D) are connected to mounting members (C).