Rigid-Spined Chain Spring Element Resists Buckling

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Solution Overview

Problem

Existing rigid-backed chains in door and window drives require complex stiffening and locking mechanisms, often consuming additional installation space and using excessive materials, while struggling to maintain stability under buckling forces and vibrations.

Innovation Solution

A rigid-backed chain with a spring element that inhibits bending in the first joint direction, featuring spring arms that move to adjacent joints to resist flexing, and stiffening straps or support sections on link plates to secure the chain in the second joint direction, allowing for reliable power transmission without additional locking mechanisms or increased chain pitch.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If complex stiffening and locking mechanisms are used to maintain stability under buckling forces, then the chain stability is improved, but the device complexity and installation space increase

Engineering Contradiction:
Improvechain stabilityVSAvoidstiffening and locking mechanisms
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent changes the physical state of the chain by introducing a spring element that applies prestressing force to the chain links. This parameter change (applying continuous compressive force) transforms the chain's behavior under buckling loads, enabling it to maintain stability without complex locking mechanisms. The spring element continuously adjusts to maintain optimal tension, converting a static structure into a dynamically adapted one.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses simplified stiffening contours with support sections that replicate the essential function of complex locking mechanisms. Instead of multiple locking elements, the support sections on chain links provide sufficient guidance and stability when combined with the spring element's prestressing force, achieving the same stabilizing effect with much simpler geometry.

Inventive Principle:
Principle #26Copying

2Reliability

If additional locking mechanisms are added to prevent buckling, then the chain reliability is improved, but the device complexity and material usage increase

Engineering Contradiction:
Improvechain reliabilityVSAvoidlocking mechanisms
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The spring element serves multiple functions simultaneously: it provides prestressing force to maintain chain tension, guides the chain through deflection, and prevents buckling through continuous contact with the chain links. This self-service approach eliminates the need for separate locking mechanisms, as the spring element inherently performs all necessary stabilization functions through its elastic properties and geometric configuration.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The spring element is designed as a multi-functional component that combines stiffening, guiding, and locking functions into a single element. The stiffening contours on chain links similarly serve multiple purposes: providing structural support, guiding chain movement, and preventing lateral deviation. This multi-functionality reduces the total number of components needed while maintaining reliability.

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

3Stability of the object's composition

If the chain pitch is increased to accommodate stiffening mechanisms, then the chain stability is improved, but the chain length and installation space increase

Engineering Contradiction:
Improvechain stabilityVSAvoidchain pitch
Core Design Contradiction:
Stability of the object's compositionVSLength of moving object

Solution Approach 1:

The spring element is nested within the existing chain link structure, utilizing the space between adjacent links without requiring additional external components. The stiffening contours are integrated directly into the chain link geometry, with support sections that fit within the natural clearance of the link plates. This nesting approach maintains compact chain pitch while providing sufficient stabilization.

Inventive Principle:
Principle #7Nested doll (Nesting)

4Ease of operation

If complex stiffening contours are used to guide the chain, then the chain guidance is improved, but the manufacturing complexity and material usage increase

Engineering Contradiction:
Improvechain guidanceVSAvoidstiffening contours
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The guidance function is segmented between two simple components: the spring element provides continuous elastic guidance through its contact with chain links, while the stiffening contours provide discrete geometric guidance at specific locations. This segmentation allows each component to have simple, easily manufacturable geometry while collectively providing comprehensive guidance functionality.

Inventive Principle:
Principle #1Segmentation

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 solution enables the chain to transmit forces effectively during overrun and reduce vibrations, allowing for the use of smaller chain drive wheels and operation in vibration-loaded areas, while preventing unintentional buckling and maintaining stability without complex constructions.

Implementation Method 1

a spring element having at least one first spring arm being provided, the spring element being supported on a chain joint, the first spring arm moving to an adjacent chain joint with which it is under the pretension of the spring element movably in contact extends to resist flexing of the rigid-backed chain

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2799738B1Rigid-spined chain
Publication Date: 2015.08.05 IWIS ANTRIEBSSYST
  • EP2799738B1 patent drawingFigure 1~3
  • EP2799738B1 patent drawingFigure 4
  • EP2799738B1 patent drawingFigure 5~6

AI summary

An anti-backbend chain comprises a plurality of alternate chain links joined by respective chain hinges, a spring element comprising at least a first spring arm being provided. The spring element rests on a chain hinge and the first spring arm extends to a neighbouring chain hinge and is movably in contact therewith under the biasing force of the spring element, so as to obstruct bending of the anti-backbend chain in a first pivot direction. In addition, an anti-backbend chain drive is provided, in particular a chain drive for driving automated door or gate systems.