Circular Knitting Machine Sinker Cover Positioning

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Solution Overview

Problem

In circular hosiery knitting machines, the centering of the sinker cover with respect to the needle cylinder is not precise due to the constant motion of the needle cylinder, leading to variations in stitch tension and reduced knitting precision, especially in high-precision seamless knitting applications.

Innovation Solution

The machine incorporates adjustment means between the sinker cover and the supporting structure to adjust the sinker cover's position perpendicular to the needle cylinder axis, using actuators and eccentric adjustment columns to maintain precise alignment, independent of the needle cylinder's motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the sinker cover is centered with respect to the needle cylinder during fine-tuning, then the initial position alignment is achieved, but the position precision deteriorates because the needle cylinder constantly moves during operation

Engineering Contradiction:
Improvesinker cover position precisionVSAvoidposition stability during operation
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces a fixed reference frame (supporting structure) as an intermediary between the sinker cover and the needle cylinder. Instead of centering the sinker cover relative to the moving needle cylinder, the adjustment means is fixed to the supporting structure, providing a stable reference that does not change during operation. This mediator resolves the contradiction by decoupling the sinker cover positioning from the needle cylinder's constant motion.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent inverts the conventional approach by not adjusting the sinker cover position relative to the needle cylinder, but rather fixing the adjustment means to the supporting structure and allowing the needle cylinder to rotate independently. This inversion transforms the problem from maintaining position during motion to establishing position independent of motion, thereby resolving the precision-stability contradiction.

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

2Productivity

If the needle cylinder rotates at high speed during operation, then productivity is improved, but the position of the sinker cover varies relative to the needle cylinder, reducing knitting precision

Engineering Contradiction:
Improveknitting speedVSAvoidstitch tension uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The fixed reference frame (supporting structure) acts as a mediator that maintains stable positioning of the sinker cover independent of the needle cylinder's high-speed rotation. The adjustment means being fixed to the supporting structure ensures that the sinker cover remains in the correct position throughout the rotation cycle, preventing position variations that would affect stitch tension uniformity while allowing high productivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the positioning function from the rotating needle cylinder by fixing the adjustment means to the supporting structure. This segmentation allows the needle cylinder to rotate at high speeds for productivity while the sinker cover position is maintained by the independent, fixed reference system, thereby preserving manufacturing precision.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If adjustment means are added to fix the sinker cover position, then position precision is improved, but device complexity increases

Engineering Contradiction:
Improvesinker cover position precisionVSAvoidstructure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The adjustment means, once fixed to the supporting structure, serves multiple functions: it maintains sinker cover position precision during high-speed operation, provides a stable reference frame, and eliminates the need for continuous active adjustment. This multi-functionality reduces overall system complexity despite adding initial structural elements, as it eliminates the need for complex active control systems.

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

Data Source

PatentEP2681354B1Circular hosiery knitting machine of the seamless type with high stitch forming precision
Publication Date: 2018.01.10 SANTONI SPA
  • EP2681354B1 patent drawingFigure 1
  • EP2681354B1 patent drawingFigure 2
  • EP2681354B1 patent drawingFigure 3~5

AI summary

A circular hosiery knitting machine of the seamless type, comprising a supporting structure and a needle cylinder provided with a plurality of axial slots, each of which accommodates a needle which can be actuated with a reciprocating motion along the corresponding axial slot; a sinker ring being arranged around the upper end of the needle cylinder being provided with a plurality of radial slots, each of which accommodates a sinker, which can move with a reciprocating motion along the corresponding radial slot, each sinker being provided with a heel which protrudes upward from the corresponding radial slot and can engage at least one path defined in a sinker cover which faces in an upper region the sinker ring, the needle cylinder being actuatable with a rotary motion about its own axis with respect to the supporting structure and to the sinker cover.