Pretensionable Locking Assembly for One-Handed Thread Engagement

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Solution Overview

Problem

Current pretensionable locking systems for medical instruments require additional effort from surgeons during operations, as they need to manually press the outer body onto the first external thread before screwing it tight, diverting attention from the primary task.

Innovation Solution

A pretensionable locking system with an outer locking body and an inner locking body, featuring a resilient radially inward projecting retaining element and a rigid, ramp-shaped thickening on the inner locking body, allowing the internal thread to be prestressed against the external thread, enabling easy screwing and secure locking without manual pressing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the internal thread is pushed over a radially compressible spring to achieve pre-fixing, then the spring expands to firmly seat the internal thread, but the structure becomes more complex and may increase breakage risk

Engineering Contradiction:
Improvereliability of pre-fixingVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The resilient retaining element is designed as a thin, flexible component that can be compressed radially inward during assembly and then expands to engage the external thread, providing reliable pre-fixing without complex structural mechanisms

Inventive Principle:
Principle #30Flexible shells and thin films

2Reliability

If the surgeon must press the outer body against the external thread before screwing it tight, then the locking can be achieved, but the operation time increases and productivity decreases

Engineering Contradiction:
Improvereliability of lockingVSAvoidsurgical efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The resilient retaining element automatically performs the function of pressing the outer body against the external thread during final tightening, eliminating the need for manual intervention and allowing the surgeon to complete the locking operation quickly without diverting attention from the primary surgical task

Inventive Principle:
Principle #25Self-service

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 system allows for one-handed operation, reduces the risk of breakage, ensures constant clamping force, is easy to clean and disinfect, and can withstand high forces, making it suitable for various medical applications with reduced production costs.

Implementation Method 1

the outer locking body has a resilient, radially inwardly projecting retaining element and the inner locking body has a rigid, radially outwardly projecting thickening

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3711681B1Pretensionable locking system
Publication Date: 2021.03.10 MEDIZIN MECHANIK NORD GMBH
  • EP3711681B1 patent drawingFigure 1~2a
  • EP3711681B1 patent drawingFigure 2b~2c
  • EP3711681B1 patent drawingFigure 3~4

AI summary

The invention relates to a preloadable locking system (2). The locking system (2) comprises a locking body (10) with an internal thread (12) and an inner locking body (20) with an external thread (22). In a preloaded position, the internal thread (12) rests against the external thread (22) in a first longitudinal axial direction (80) and is preloaded against the external thread (22). In a locked position, the outer locking body (10) is fixed to the inner locking body (20) by screwing the internal thread (12) onto the external thread (22). The invention is further developed in that the outer locking body (10) has a resilient, radially inwardly projecting retaining element (14) and the inner locking body (20) has a rigid, radially outwardly projecting thickening (24).In the pre-tensioned position, the retaining element (14) rests against the thickening (24) in a second longitudinal axial direction (85), which is opposite to the first longitudinal axial direction (80).