Sewing Machine Feed Distance Correction via Stitch Counting

Solution Overview

Problem

Conventional electronically-controlled sewing machines face errors in feed distance due to mechanical errors or presser foot shape, requiring manual correction through trial sewing, which is time-consuming and troublesome.

Innovation Solution

A sewing machine with a detection device to automatically set a correction value for feed distance by counting stitches and using a feed controller to adjust the feed mechanism based on the detected feed distance, eliminating the need for manual correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If manual correction through trial sewing is used, then feed distance accuracy can be improved, but time consumption and operational complexity increase

Engineering Contradiction:

Improvefeed distance accuracyVSAvoidtime for trial sewing

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The sewing machine automatically performs feed distance correction by utilizing its own stitching operation to detect and measure feed errors. The system counts stitches during normal sewing and automatically calculates correction values without requiring external intervention or separate measurement procedures, making the system self-diagnosing and self-correcting

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system implements a feedback mechanism where the actual feed distance is measured by counting stitches during sewing operations, compared against the intended feed distance, and correction values are automatically applied based on the detected discrepancy. This closed-loop feedback eliminates the need for manual trial and error correction

Inventive Principle:

Principle #23Feedback

2Manufacturing precision

If manual correction through trial sewing is used, then feed distance accuracy can be improved, but operational complexity increases

Engineering Contradiction:

Improvefeed distance accuracyVSAvoidease of correction

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The sewing machine automatically performs feed distance correction by utilizing its own stitching operation to detect and measure feed errors. The system counts stitches during normal sewing and automatically calculates correction values without requiring external intervention or separate measurement procedures, making the system self-diagnosing and self-correcting

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical adjustment procedures with an automated electronic control system that uses stitch counting and microprocessor-based calculations to determine and apply correction values, eliminating the need for operators to perform manual trial sewing and adjustments

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If automated stitch counting is implemented, then correction accuracy is improved, but device complexity increases

Engineering Contradiction:

Improvefeed distance measurementVSAvoidcomplexity of detection and control system

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The sewing machine's existing stitch counting mechanism, originally designed for pattern control and stitching operations, is repurposed to simultaneously perform feed distance measurement. This multi-functional use of existing components avoids adding separate dedicated measurement devices, thereby limiting the increase in system complexity while achieving accurate feed distance detection

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The sewing machine automatically performs feed distance correction by utilizing its own stitching operation to detect and measure feed errors. The system counts stitches during normal sewing and automatically calculates correction values without requiring external intervention or separate measurement procedures, making the system self-diagnosing and self-correcting

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS8042479B2Sewing machine

Publication Date: 2011.10.25 BROTHER KOGYO KK

AI summary

A sewing machine includes a detection device that detects whether a feed distance by which the piece of work cloth is shifted by a feed dog in the back-and-forth or right-and-left direction has reached a predetermined distance, a counting device that counts a number of forward feed stitches and a number of backward feed stitches which are sewn when the piece of work cloth is shifted backward and forward, respectively, by the predetermined feed distance detected by the detection device or a number of leftward feed stitches and a number of rightward feed stitches which are sewn when the piece of work cloth is shifted leftward and rightward, respectively, by the predetermined feed distance, and a correction value setting device that sets a correction value to correct the feed distance based on a result of the counting of the number of stitches by the counting device.