Compound Needle Waste Discharge Window Design

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Solution Overview

Problem

Existing compound needles used in flat knitting machines suffer from insufficient strength and waste accumulation in the slider groove, leading to instability in hook operation and stitch formation, particularly in fine-gauge machines.

Innovation Solution

A compound needle design featuring a waste discharge window on the needle body's side face, connected to the rear end of the slider groove, and a waste discharge hole in the intermediate portion of the needle body, which facilitates waste removal and prevents accumulation, combined with an engaging portion to prevent the slider from rising.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If a hole is formed extending greater than or equal to half the length of the bottom portion of the slider groove to discharge waste, then waste discharge is improved, but the strength of the needle body in the thickness direction is reduced

Engineering Contradiction:
Improvewaste accumulationVSAvoidstrength of needle body
Core Design Contradiction:
Object-generated harmful factorsVSStrength

Solution Approach 1:

The waste discharge path is segmented into two separate features: a waste discharge hole formed in the lower face at an intermediate portion of the bottom portion, and a waste discharge window formed in the side face connected to the rear end portion. This segmentation allows waste to be discharged through multiple paths without requiring a single large hole that would compromise structural integrity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The waste discharge window is formed in the side face of the needle body, utilizing the lateral dimension rather than only the vertical dimension. This allows waste to be discharged from the rear end side of the slider groove through a different spatial dimension, reducing the need for large holes in the thickness direction that would weaken the needle body.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If a large hole is formed in the needle body for waste discharge, then waste discharge capability is improved, but the needle body becomes weaker and more prone to breakage in fine-gauge machines

Engineering Contradiction:
Improvewaste discharge efficiencyVSAvoidneedle body durability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The waste discharge function is divided between a small waste discharge hole in the lower face and a waste discharge window in the side face. This segmentation provides sufficient waste discharge capability while using smaller, less intrusive openings that do not significantly compromise the needle body's strength and durability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The waste discharge window acts as an intermediary structure that facilitates waste removal by providing an additional discharge path connected to the rear end portion of the slider groove. This intermediary feature enhances waste discharge efficiency without requiring large modifications to the needle body structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If waste accumulates in the slider groove, then sliding of the slider is hindered, but forming a large hole to prevent accumulation reduces needle body strength

Engineering Contradiction:
Improveslider sliding smoothnessVSAvoidneedle body strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The waste discharge system is segmented into a waste discharge hole and a waste discharge window, providing multiple pathways for waste removal. This ensures smooth slider operation by preventing waste accumulation without requiring a single large hole that would weaken the needle body.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The waste discharge features are strategically positioned: the waste discharge hole is located at an intermediate portion of the bottom portion, and the waste discharge window is connected to the rear end portion of the slider groove. This local placement optimizes waste discharge at critical locations while preserving the overall strength of the needle body.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3425097B1Compound needle
Publication Date: 2020.04.15 SHIMA SEIKI MFG LTD
  • EP3425097B1 patent drawingFigure 1(A)~1(C)
  • EP3425097B1 patent drawingFigure 2(I)~2(II)
  • EP3425097B1 patent drawingFigure 3(A)~3(C)

AI summary

The present invention provides a compound needle that has sufficient strength and suppresses the accumulation of waste in a slider groove. The compound needle 1 includes a needle body 2 that has a hook 20 provided at the tip and a slider groove 21 provided in an upper end face, and a slider 3 that is slidably fitted into the slider groove 21 and opens and closes the hook 20. The compound needle 1 also includes a waste discharge window 4 that is formed in a side face of the needle body 2 and is in communication with a portion of the slider groove 21 located on a rear end side in the sliding direction of the slider 3. The waste discharge window 4 has a shape capable of accommodating the rear end of a portion of the slider 3 that slides on a bottom portion 21b of the slider groove 21, when the slider 3 is at the most withdrawn position in the sliding direction.