Needle Bar Stroke Adjustment via Radial Crank Pivoting

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Solution Overview

Problem

Existing needle bar handling systems for sewing machines require significant time and effort to adjust the needle bar stroke length according to the thickness of the fabric, reducing efficiency when switching between different fabric thicknesses.

Innovation Solution

A needle bar handling system with an adjustment device that allows the crank to be pivoted on a movable element, which can be radially shifted and fixed at various positions, altering the distance between the pivot pin and the cylindrical element's axis of rotation, thereby adjusting the needle bar stroke length.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the needle bar shaft, crank handle, or cylindrical element is replaced to change the needle bar stroke length, then the sewing machine can accommodate different fabric thicknesses, but the setting time increases significantly and efficiency is reduced

Engineering Contradiction:
Improveability to accommodate different fabric thicknessesVSAvoidsetting time for needle bar stroke adjustment
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The invention applies the dynamics principle by replacing the static, fixed needle bar handling system with a dynamic, adjustable one. The mobile element can be shifted along the cylindrical element to different positions, allowing the needle bar stroke length to be dynamically changed without replacing entire components. This enables the system to adapt to different fabric thicknesses while maintaining quick adjustment capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention segments the needle bar handling system into distinct functional elements: a fixed element permanently mounted on the cylindrical element, and a mobile element that can be independently positioned. This segmentation allows only the necessary portion (the mobile element position) to be adjusted, rather than replacing entire components like the needle bar shaft or crank handle, thus reducing adjustment time.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If multiple components are replaced to adjust the needle bar stroke, then the required stroke length can be achieved, but the complexity of the handling system increases

Engineering Contradiction:
Improveadjustability of needle bar stroke lengthVSAvoidcomplexity of needle bar handling system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention merges the adjustment functionality into a single integrated mechanism consisting of the mobile element that can be positioned along the cylindrical element. This combines multiple adjustment functions (changing stroke length, adjusting pivot position) into one unified system, reducing the overall complexity compared to having separate replaceable components for each adjustment need.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cylindrical element with its mobile and fixed elements serves multiple functions: it acts as the mounting structure for the crank, provides the adjustment mechanism through the mobile element's position, and defines the geometric constraints for the needle bar stroke. This multi-functionality reduces the need for separate specialized components, simplifying the overall system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Device complexity

If the needle bar handling system is designed for fixed stroke length, then the system structure is simpler, but it cannot accommodate varying fabric thicknesses

Engineering Contradiction:
Improvestructural simplicity of handling systemVSAvoidability to sew different fabric thicknesses
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The invention introduces dynamic adjustability into an otherwise simple structural system. The mobile element can be freely positioned along the cylindrical element, allowing the needle bar stroke length to be changed based on fabric thickness requirements, while the overall system structure remains relatively simple and maintains ease of operation.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4038230B1Handling system for sewing machines
Publication Date: 2024.01.10 VI BE MAC SPA
  • EP4038230B1 patent drawingFigure 1
  • EP4038230B1 patent drawingFigure 2

AI summary

This is a needle bar handling system for a sewing machine. More specifically, it is a handling system that allows the length of the needle bar stroke to be varied according to the thickness of the fabric to be sewn.