Sewing Machine Needle Bar Rocking Control via Optical Imaging

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing sewing machines face challenges in accurately determining and maintaining the correct needle location, leading to potential interference with the needle plate and subsequent damage, especially after large impacts or mechanical loosening, due to indirect detection methods of the needle's rocking position.

Innovation Solution

A sewing machine equipped with a photographing device to capture images of the needle bar and needle plate, a control device to set and control the range of rocking motion, and a button presser foot to hold the needle bar, allowing for direct recognition and correction of the needle's position relative to the needle holes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a proximity sensor is used to detect the rocking position of the needle bar, then the needle position can be monitored, but the detection accuracy is insufficient due to indirect measurement

Engineering Contradiction:

Improveneedle position monitoringVSAvoidrocking position detection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical proximity sensor detection system with an optical imaging system. A camera captures images of the needle bar and needle plate, and image processing algorithms directly calculate the needle position and rocking angle from these images, providing more accurate measurement than indirect mechanical sensing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a visual copy (image) of the needle bar and needle plate assembly using a camera. This optical copy is then processed to extract precise position information, allowing accurate detection of the needle rocking position without physical contact or indirect mechanical measurement.

Inventive Principle:

Principle #26Copying

2Adaptability or versatility

If the needle bar rocking range is increased to accommodate displacement, then sewing flexibility is improved, but the risk of needle interference with the needle plate increases

Engineering Contradiction:

Improveneedle position adjustment rangeVSAvoidneedle interference with needle plate

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback control system where the camera continuously monitors the needle bar position and rocking angle. The control device receives this visual feedback and dynamically adjusts the rocking range limits to prevent the needle from interfering with the needle plate, while still allowing maximum safe movement for accommodation of displacement.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent makes the needle bar rocking range dynamic rather than fixed. The control device adjusts the allowable rocking limits in real-time based on the detected needle position and orientation, enabling the system to adapt to displacement while maintaining safety margins to prevent needle-plate interference.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8261679B2Sewing machine provided with needle bar rocking mechanism

Publication Date: 2012.09.11 BROTHER KOGYO KK

AI summary

A sewing machine includes a needle bar to which a needle is attached, a needle bar rocking mechanism which rocks the needle bar, a needle plate having a needle hole through which the needle is passed, an imaging device which images a lower part of the needle bar, a setting section which sets a range of rocking motion of the needle bar based on an image obtained by the imaging device, and a control device which controls the needle bar rocking mechanism based on the range of rocking motion set by the setting section.