Dynamic Chain Tensioner for Sheet Processing Machines

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Vibration phenomena in chain train systems of sheet processing machines lead to increased mechanical stresses and reduced service life, necessitating more powerful springs that exacerbate the issue.

Innovation Solution

A dynamic tensioning device using a current-controlled linear motor to apply variable tension forces based on instantaneous machine speed, reducing vibrations and mechanical stresses on chain trains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If more powerful springs are used to reduce vibration phenomena, then vibration reduction is improved, but mechanical stresses on chain trains increase and service life decreases

Engineering Contradiction:
Improvevibration phenomenaVSAvoidservice life of chain trains
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies a dynamic tensioning system using a linear motor that continuously adjusts the tension force applied to the chain train based on real-time vibration detection. Unlike static spring tensioners that apply constant force, this dynamic system modulates tension to match actual vibration conditions, reducing unnecessary mechanical stress while maintaining vibration control effectiveness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent replaces the purely mechanical spring-based tensioning system with an electromechanical system combining a linear motor, sensor, and control unit. This substitution enables precise, adaptive tension control that responds to actual vibration conditions rather than applying continuous high force, thereby reducing mechanical stress on chain train components.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If higher machine speeds are used to increase productivity, then productivity is improved, but vibration phenomena become more violent and mechanical stresses increase

Engineering Contradiction:
Improvemachine speedVSAvoidvibration phenomena
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback control system where sensors continuously monitor vibration levels in the chain train and feed this information to a control unit. The control unit then adjusts the linear motor's tension output in real-time based on detected vibration conditions, enabling the system to maintain effective vibration control at higher operating speeds without excessive mechanical stress.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The dynamic tensioning system adapts its force output to match the varying vibration conditions that occur at different machine speeds. By continuously adjusting tension based on real-time conditions rather than using fixed high tension, the system enables higher productivity speeds while controlling vibration effects.

Inventive Principle:
Principle #15Dynamics

3Strength

If reinforced chain trains are used to withstand higher mechanical stresses, then strength is improved, but device complexity and cost increase

Engineering Contradiction:
Improvemechanical stress resistanceVSAvoidchain train structure
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

Instead of mechanically reinforcing the chain train structure to handle higher stresses, the patent substitutes a controlled tensioning system using a linear motor. This approach maintains standard chain train design while using active tension control to manage stress levels, avoiding the complexity and cost of structural reinforcement.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operational parameters of the tensioning system dynamically, adjusting the force applied by the linear motor based on actual vibration conditions. This allows the use of standard chain train components rather than reinforced ones, as the controlled parameter changes prevent excessive stress accumulation.

Inventive Principle:
Principle #35Parameter changes

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

Significantly extends the lifespan of chain trains by reducing wear and mechanical stresses while maintaining efficient operation.

Implementation Method 1

a drive member (51) in the form of a linear motor generating a variable force (Fv) whose intensity is a function of the instantaneous rate of the machine

Methodology Applied
Scientific EffectLinear motor: Linear Motor

Implementation Method 2

a return device (65) in the form of a spring applying a substantially constant force (Fc)

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP2619117B1Machine for processing sheet members including a chain-set tensioner
Publication Date: 2019.02.20 BOBST MEX SA
  • EP2619117B1 patent drawingFigure 1~2
  • EP2619117B1 patent drawingFigure 3~4
  • EP2619117B1 patent drawingFigure 5a~5d

AI summary

The invention relates to a machine for processing sheet members (10), including chain sets (80) and at least one tensioning device (50) that generates a tensile force in said chain sets. According to the invention, the chain-set tensioning device includes a driving member (51) capable of generating a variable force (Fv), the intensity of which depends on the instantaneous pace of the machine. The wear of the chain sets (80) can be substantially reduced, and the lifespan thereof is substantially lengthened.