Sewing Machine Presser Foot Tilt Control for Fabric Thickness

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional sewing machines face difficulties in maintaining consistent seam quality due to variations in fabric thickness, leading to irregular stitches and misalignment of fabric edges, as the presser foot struggles to follow the fabric's surface accurately.

Innovation Solution

A presser device with a control system that detects the inclination of the presser foot and adjusts pressure independently, using a sensor and articulated mechanism to ensure uniform pressure distribution across the fabric, even as the fabric thickness changes, allowing the presser foot to tilt and maintain contact with the fabric.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the presser foot is hinged on a presser bar to allow oscillation following fabric development, then the presser foot can follow slight variations of fabric thickness, but it cannot appropriately follow considerable variations of fabric thickness, resulting in irregular seams and misalignment

Engineering Contradiction:
Improveability to follow fabric thickness variationsVSAvoidseam quality and fabric alignment
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The presser foot is made dynamically adjustable through an articulated mechanism that allows it to change its inclination angle relative to the presser bar. This dynamic adaptation enables the presser foot to follow considerable variations in fabric thickness while maintaining consistent pressing force, thereby resolving the contradiction between adaptability and manufacturing precision.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the inclination parameter of the presser foot relative to the presser bar by varying the articulation angle. This parameter change allows the presser foot to adapt to different fabric thickness profiles while maintaining appropriate contact pressure, thus improving both adaptability and seam quality simultaneously.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the presser foot extends its path and is lifted from the fabric to avoid jamming, then it can handle thickness variations, but it cannot maintain continuous pressure on the fabric, resulting in imperfect superimposition and misalignment

Engineering Contradiction:
Improveavoidance of presser foot jammingVSAvoidfabric superimposition quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

Instead of lifting the presser foot to avoid jamming, the articulated mechanism dynamically adjusts the inclination angle to maintain continuous contact with the fabric surface. This dynamic adjustment allows the presser foot to navigate thickness variations without losing pressure contact, thereby maintaining both reliability and manufacturing precision.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If elastic means are added to the presser foot to follow fabric thickness variations, then the presser foot can adapt to thickness changes, but the system cannot detect variations and control pressure, resulting in insufficient precision

Engineering Contradiction:
Improveability to follow fabric thickness variationsVSAvoiddetection and control of pressure
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

A sensor detects the inclination angle of the presser foot relative to the presser bar and provides feedback to a control system. This feedback mechanism enables real-time detection of fabric thickness variations and automatic adjustment of the presser foot position, achieving both adaptability and measurement precision simultaneously.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system replaces simple elastic mechanical means with an articulated mechanism controlled by sensors and a control unit. This substitution introduces detection and active control capabilities, transforming a passive mechanical system into an intelligent system that can precisely detect and respond to fabric thickness variations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Manufacturing precision

If a sensor and control device are added to detect presser foot inclination and control pressure, then the system can detect and respond to thickness variations, but the device complexity increases

Engineering Contradiction:
Improveseam quality and stitch uniformityVSAvoidpresser device structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The articulated mechanism serves multiple functions: it provides the structural connection between presser bar and presser foot, enables inclination adjustment for thickness variation following, and works with the sensor to provide feedback control. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity while achieving high manufacturing precision.

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

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

This solution ensures uniform stitch length and precise alignment of fabric edges, achieving high-quality seams by accurately following fabric thickness variations and maintaining consistent pressure, regardless of the fabric's texture or angle.

Implementation Method 1

a sensor which is fit to detect the inclination of the presser foot in respect to the presser bar

Methodology Applied
Scientific EffectInclination detection:

Implementation Method 2

an articulated mechanism which is connected with the presser foot and acts on the sensor

Methodology Applied
Scientific EffectMechanical linkage:

Implementation Method 3

pressing means suited to be actuated on the presser foot... pressure control means suited to vary the pressure on the presser foot

Methodology Applied
Scientific EffectPressure control:

Data Source

PatentEP2535449B1Presser device and sewing machine comprising said device
Publication Date: 2014.04.16 VI BE MAC SPA
  • EP2535449B1 patent drawingFigure 1
  • EP2535449B1 patent drawingFigure 2
  • EP2535449B1 patent drawingFigure 3

AI summary

Presser device couplable with a sewing machine (10) having a control system and comprising a head (14) and a base (12) on which an article (50) to be sewn rests. The presser device comprises a presser bar (24) couplable with the head (14), and a presser foot (26), hinged through a pivot (28) on said presser bar (24) so as to vary the inclination of the presser foot (26) in respect to the presser bar (24). The presser foot (26) is fit to push the article (50) in order to maintain said article under pressure on the base (12) even if the thickness of the article (50) varies.