Sewing Machine Needle Bar Rocking Mechanism for Free Motion Embroidery

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Solution Overview

Problem

Conventional sewing machines require expensive XY drive mechanisms to move fabrics in both lateral and longitudinal directions for satin stitch embroidery, leading to high costs and limitations in font size and style adjustments, with fixed needle bar swing amounts resulting in unpleasant embroidery appearances.

Innovation Solution

A sewing machine with a vertically movable needle bar and a rocking mechanism that adjusts amplitude via a control unit during free motion sewing, allowing users to manipulate fabric with both hands and adjust needle bar swing independently, eliminating the need for expensive XY drive mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an XY drive mechanism is equipped to move fabric in both lateral and longitudinal directions for satin stitch embroidery, then embroidery capability is improved, but device cost and complexity increase significantly

Engineering Contradiction:
Improveembroidery capabilityVSAvoidmechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the fabric movement function from the traditional XY drive mechanism and transfers it to manual operation. The needle bar rocking mechanism remains to provide lateral needle movement for satin stitch formation, while the feed dog is disabled during free motion embroidery, allowing the operator to manually position the fabric as needed.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of moving the fabric automatically through an XY mechanism to achieve embroidery patterns, the patent inverts the approach by keeping the needle bar rocking mechanism active and allowing manual fabric manipulation. This reverses the traditional control paradigm from fabric-driven to needle-driven embroidery.

Inventive Principle:
Principle #13The other way round (Inversion)

2Manufacturing precision

If an XY drive mechanism is equipped for satin stitch embroidery, then embroidery quality is improved, but manufacturing cost increases

Engineering Contradiction:
Improveembroidery qualityVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces the expensive XY drive mechanism with a simpler, more cost-effective configuration. The essential embroidery function is achieved through the existing needle bar rocking mechanism combined with manual fabric handling, eliminating the need for costly additional drive systems while maintaining satisfactory embroidery quality.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If the needle bar swing amount is fixed, then mechanism simplicity is maintained, but embroidery appearance quality deteriorates

Engineering Contradiction:
Improvemechanism simplicityVSAvoidembroidery appearance
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent introduces dynamic adjustability to the needle bar swing mechanism, allowing the operator to modify the swing amount during operation. This is achieved through a swing amount adjustment mechanism that enables real-time changes to the needle bar lateral movement range, improving embroidery appearance without significantly complicating the overall system.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2412858B1Sewing machine
Publication Date: 2013.07.31 AISIN SEIKI KK
  • EP2412858B1 patent drawingFigure 1
  • EP2412858B1 patent drawingFigure 2
  • EP2412858B1 patent drawingFigure 3

AI summary

A low cost and easy-to-use sewing machine is provided which is capable of performing free motion sewing. The sewing machine includes a needle bar to which a needle can be mounted, a needle bar vertical moving mechanism, a needle bar swing mechanism causing the needle bar to swing in a lateral direction relative to a longitudinal direction along which a feed dog operates for straight stitch, and a control portion for adjusting a swing amount of the needle bar which is brought into swing movement in the lateral direction by the needle bar swing mechanism.