Spaced Coil Return Springs for Robot Cable Guides

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Solution Overview

Problem

Existing cable guiding devices for industrial robots have return springs with large surfaces that accumulate contaminants, making them difficult to clean, particularly in food and drug production environments.

Innovation Solution

The return springs' wire turns are spaced apart to maintain a minimum distance, allowing for effective cleaning, and multiple springs can be used in parallel to increase restoring force without increasing size, with a stop preventing pivoting in the opposite direction and notches to prevent slippage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the return spring is designed as a conventional torsion coil spring with closely wound coils, then the spring can provide sufficient restoring force, but the coils accumulate contaminants and are difficult to clean

Engineering Contradiction:
Improverestoring forceVSAvoidcleanability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention changes the geometric parameters of the return spring by spacing the coils at distances of at least 3 mm (preferably at least 4 mm) from one another in the rest position of the pivot arm. This parameter change maintains the restoring force capability while creating gaps that allow cleaning agents to reach all surfaces of the spring wire, solving the cleanability problem without sacrificing mechanical performance

Inventive Principle:
Principle #35Parameter changes

2Force

If multiple return springs are used in parallel to increase restoring force, then the total force increases, but the device complexity increases

Engineering Contradiction:
Improverestoring forceVSAvoidnumber of springs
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The invention segments the restoring force function by using multiple identical return springs arranged in parallel. Each spring is independently constructed with spaced coils, and together they provide the total required restoring force. This segmentation allows the system to achieve higher force without requiring a single oversized spring that would be difficult to clean, while the modular identical design minimizes complexity through standardization

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If the pivot arm is allowed to pivot freely in both directions, then the robot has full movement range, but the spring coils may come into contact and accumulate contaminants

Engineering Contradiction:
Improvemovement rangeVSAvoidcontaminant accumulation
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The invention applies preliminary action by pre-spacing the spring coils at distances of at least 3 mm before any contamination can occur. This preventive geometric design ensures that even when the pivot arm moves through its full range of motion, the coils maintain sufficient separation to allow cleaning agents to access all surfaces, preventing contaminant accumulation before it becomes a problem

Inventive Principle:
Principle #10Preliminary action

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

This design enables easy cleaning of the return springs and enhances the stability and durability of the cable guiding system by maintaining a consistent distance between wire turns and distributing the restoring force effectively.

Implementation Method 1

at least one return spring (38), against whose restoring force the pivot arm (22) can be pivoted from a rest position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4169680B1Device for guiding conduits
Publication Date: 2024.06.12 MURRPLASTIK SYSTEMTECHNIK GMBH
  • EP4169680B1 patent drawingFigure 1
  • EP4169680B1 patent drawingFigure 2a
  • EP4169680B1 patent drawingFigure 2b

AI summary

The invention relates to a device (14) for guiding cables (16) on an industrial robot (10) with a swivel arm (22) for mounting on a robot axis (12) in an arrangement pivotable about a pivot axis (24) fixed to the robot axis, with a holder (26) for the cables (16) mounted on the swivel arm (22), and with at least one return spring (38) against whose return force the swivel arm (22) can be pivoted from a rest position in a first pivoting direction (44). According to the invention, the at least one return spring (38) is a tension spring designed as a helical spring, extendable against the return force in a longitudinal direction (46), the coils of which are spaced apart from each other in the longitudinal direction (46) in the rest position of the swivel arm (22).