Robot Hand Internal Cable Guide for Precise Printhead Positioning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing robotic hands for atomizers and printheads suffer from inaccuracies due to backlash in gears, elasticity of components, and mechanical play, leading to overspray and positioning inaccuracies, especially when used for precise painting applications.

Innovation Solution

A robotic hand design featuring backlash-free wave gears and direct drives, combined with high-resolution optical measuring devices for direct joint position detection, ensures minimal mechanical play and high accuracy, allowing for precise application of coating materials without overspray.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional drive trains with gears, shafts and bearings are used, then the robot hand can achieve sufficient accuracy for atomizer painting, but mechanical play and elasticity cause inaccuracies and reduce positioning precision for printhead applications

Engineering Contradiction:
Improvepositioning precisionVSAvoidmechanical play
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent replaces conventional mechanical drive trains with gears, shafts and bearings with a cable-driven mechanical system. This substitution eliminates the mechanical play and elasticity issues inherent in gear-based systems, providing a more reliable and precise positioning mechanism for the robot hand when used with printhead application devices.

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

2Volume of moving object

If compact design with coupled joints is implemented, then the robot hand structure is optimized, but couplings between drive trains increase mechanical play and reduce stiffness

Engineering Contradiction:
Improverobot hand compactnessVSAvoidstiffness
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

The patent segments the drive train system by implementing independent cable-driven mechanisms for each joint rather than coupled mechanical transmissions. This segmentation allows each joint to be controlled independently through cables, eliminating the mechanical couplings that cause play while maintaining a compact overall structure. The cable-driven design enables space-efficient routing without compromising joint stiffness.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If complex experiments and estimation algorithms are used to determine friction and dynamic parameters, then torque feedforward control can be calculated, but inaccuracies in parameter determination lead to positioning errors

Engineering Contradiction:
Improvetorque control accuracyVSAvoidpositioning accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The cable-driven mechanical system simplifies the dynamic model by eliminating complex gear transmissions and their associated friction parameters. This substitution reduces the number of difficult-to-determine parameters, making torque calculation more accurate and reducing positioning errors without requiring complex experiments and estimation algorithms.

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

Data Source

PatentEP4463295B1Robot hand with internal cable guide, in particular for carrying an application device
Publication Date: 2025.12.17 DUERR SYST AG
  • EP4463295B1 patent drawingFigure 1~2
  • EP4463295B1 patent drawingFigure 3~4
  • EP4463295B1 patent drawingFigure 5

AI summary

The invention relates to a robot hand (100), preferably for carrying an application device (60) which preferably has a printhead device (61), comprising a first joint structure (10) which can be rotated about a first axis (11), a second joint structure (20) which can be rotated about a second axis (21), a third joint structure (30) which can be rotated about a third axis (31), a cable feedthrough (40) which extends through the first joint structure (10) and through the third joint structure (30) and in which preferably at least one cable runs, and an offset (50) between the first axis (11) and the second axis (21).