Electrodynamic Setting Tool Cable Reset Without Sliding Contacts

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Solution Overview

Problem

Existing electrodynamic setting devices face inefficiencies due to wear and reduced efficiency from sliding contacts used to reset movable electrical conductors, necessitating a more efficient and direct method for returning the conductors to their initial position.

Innovation Solution

A setting device with a cable tensioned by a spring element, which holds the movable electrical conductor in a rest position and returns it after the setting operation, utilizing a force-redirecting means like a movable roller and a stop, minimizing mass and impedance to enhance efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sliding contacts are used to return the movable electrical conductor to its initial position, then the resetting function is achieved, but wear increases and efficiency decreases

Engineering Contradiction:
Improveresetting functionVSAvoidefficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent extracts and eliminates the sliding contacts from the system. Instead of using sliding contacts to return the movable electrical conductor, the invention uses a cable connected to a reel that winds and unwinds to pull the conductor back. This removal of the harmful sliding contact component directly resolves the contradiction by eliminating wear and efficiency loss while maintaining the resetting function.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If sliding contacts are used to contact the movable coils, then the resetting function is achieved, but considerable wear occurs

Engineering Contradiction:
Improveresetting functionVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent removes sliding contacts from the system entirely, replacing them with a cable-reel mechanism. This extraction eliminates the wear problem that would otherwise limit the service life of the stationary contacts, while the resetting function is maintained through the cable pulling the movable conductor back to its initial position.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If sliding contacts are used, then the resetting function is achieved, but impedance increases reducing efficiency

Engineering Contradiction:
Improveresetting functionVSAvoidefficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent eliminates sliding contacts and their associated impedance problems by using a cable-reel mechanism. The cable, being a flexible conductor with low impedance, efficiently transmits the resetting force without the electrical impedance that would reduce productivity and efficiency in sliding contact systems.

Inventive Principle:
Principle #2Taking out (Extraction)

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 reduces mass and impedance, allowing for efficient resetting of the movable electrical conductor, maintaining high efficiency and reducing wear, thus enhancing the performance of the setting device.

Implementation Method 1

a tensioning device for the at least one cable, comprising at least one spring element

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the spring element is further tensioned over the cable by the movement of the movable electrical conductor, after which (i.e., after the setting operation) the spring element springs back to a preload and pulls the movable electrical conductor back into its rest position

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 3

Electrodynamic setting devices with linear drives utilize the repulsive interaction between a first excitation coil and a movable electrical conductor

Methodology Applied
Scientific EffectElectromagnetic repulsion: Lorentz Force

Data Source

PatentEP4370283B1Setting tool
Publication Date: 2025.12.24 RHEFOR GBR
  • EP4370283B1 patent drawingFigure 1a
  • EP4370283B1 patent drawingFigure 1b

AI summary

A setting tool, comprising: at least a housing and an electrodynamic drive, wherein the electrodynamic drive comprises at least: a first excitation coil; a movable electrical conductor, for example a squirrel-cage rotor or a second coil, which is arranged movably in the setting tool; a driving-in element; a cable; a tensioning device for the at least one cable, comprising at least one spring element and a means for deflecting the force, wherein the at least one means for deflecting the force is preferably designed as a movable roller which furthermore preferably has a groove for receiving the cable; and a stop; characterized in that the cable is fastened at one end directly or indirectly to the movable electrical conductor and at the other end directly or indirectly to the housing of the setting tool, and in that, in the inoperative state of the setting tool, the cable is tensioned by the tensioning device, by pretensioning of the spring element, so as to keep the movable electrical conductor pulled into an inoperative position defined by the stop, and wherein, during a setting operation, the movement of the movable electrical conductor further tensions the spring element via the cable, after which the spring element rebounds again to a pretensioned state and pulls the movable electrical conductor back into its inoperative position.