Electrosurgical Instrument Pivot Joint and Knife Guide Recess

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Solution Overview

Problem

Existing electrosurgical instruments often have complex designs for knife guidance at the pivot axis, leading to eccentric knife storage and increased difficulty in cleaning and maintaining the swivel joint.

Innovation Solution

The design features a pivot joint formed by a single bearing pin and recess, with the knife guide recess extending along the pivot axis, avoiding eccentric storage and simplifying the structural design by eliminating the need for guiding the knife through bearing pins, and incorporating a flushing opening for improved accessibility and cleaning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the knife is guided through bearing pins in the pivot joint, then the knife can be positioned at the pivot axis, but the design becomes complex and cleaning becomes difficult

Engineering Contradiction:
Improveknife positioning at pivot axisVSAvoidpivot joint structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The knife guide recess is extracted from the pivot joint structure itself and placed in the second branch, separating the knife guidance function from the pivot bearing function. This eliminates the need for complex guiding mechanisms within the pivot joint while maintaining precise knife positioning at the pivot axis during operation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The instrument is divided into functional segments: the pivot joint (bearing pin and recess) handles rotation, while the knife guide recess in the second branch handles knife guidance. This segmentation allows each component to be simple and easy to clean while achieving the combined function of precise knife positioning and smooth pivoting.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If the knife guide recess extends through the bearing pin, then the knife can be guided centrally, but the pivot joint becomes harder to clean

Engineering Contradiction:
Improvecentral knife guidanceVSAvoidpivot joint cleaning
Core Design Contradiction:
Manufacturing precisionVSEase of repair

Solution Approach 1:

The knife guide recess is extracted from the bearing pin and relocated to the second branch structure. This extraction maintains central knife guidance functionality while completely opening the bearing pin and recess for easy access and cleaning, eliminating the problem of trapped debris in closed recesses.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The second branch acts as an intermediary structure that provides the knife guide recess function without interfering with the pivot joint's cleaning. The recess in the second branch guides the knife centrally while the pivot joint remains openly accessible for maintenance.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If multiple bearing pins are used to form the pivot joint, then the joint is more stable, but the knife guide design becomes more complex

Engineering Contradiction:
Improvepivot joint stabilityVSAvoidknife guide structure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The knife guidance function is extracted from the multi-pin pivot joint structure and assigned to a single recess in the second branch. This allows the pivot joint to use multiple bearing pins for stability without adding complexity to the knife guide, as the two functions are spatially and structurally separated.

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

This configuration ensures a simple, cost-effective design that prevents eccentric knife movement and enhances accessibility for cleaning and maintenance, while maintaining effective tissue sealing and cutting capabilities.

Implementation Method 1

The bearing pin (24) engages in the bearing recess (25). This forms a pivot joint (13) by means of which the first branch (11) is pivotally mounted on the second branch (12) about a pivot axis S.

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The second branch (12) has a knife guide recess (61) along which a knife (60) is guided in a direction of movement B

Methodology Applied
Scientific EffectMechanical guidance:

Implementation Method 3

A current can be passed through the tissue clamped between the jaws via the tissue contact surfaces, for example, to seal the tissue.

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 4

A current can be passed through the tissue clamped between the jaws via the tissue contact surfaces

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3744266B1Electro-surgical instrument
Publication Date: 2024.02.28 ERBE ELEKTROMEDIZIN GMBH
  • EP3744266B1 patent drawingFigure 1~2
  • EP3744266B1 patent drawingFigure 3~4
  • EP3744266B1 patent drawingFigure 5~7

AI summary

The invention relates to an electrosurgical instrument (10) with a first branch (11) and a second branch (12). The two branches are pivotally mounted to one another by means of a pivot joint (13). The pivot joint (13) is formed by a bearing pin (24) on the second branch (12) and a corresponding bearing recess (25) on the first branch (11). Preferably, a single pivot joint (13) with a single bearing recess (25) and a single bearing pin (24) is provided. Laterally adjacent to the pivot bearing location where the bearing pin (24) projects into the bearing recess (25), a knife guide recess (61) for the movably guided mounting of a knife (60) is provided in the second branch (12). The knife guide recess (61) is arranged parallel to the pivot axis defined by the pivot joint (13) and is preferably located directly adjacent to an axial end of the pivot pin. The swivel joint (13) orThe pivot bearing point formed by the pivot joint, where the bearing pin (24) is located in the bearing recess (25), is arranged only on one side of the knife guide recess in a direction parallel to the pivot axis. The other side is free of pivot bearing components and has no means by which the two branches are pivotably mounted to one another along the pivot axis.