Sinker Cam Segments with Linear Breaks for High-Speed Knitting

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Solution Overview

Problem

Existing circular knitting machines have breaks in sinker cam segments located at acceleration areas, leading to increased angles of cam surfaces and reduced circumferential distance for sinker travel, which complicates high-speed operations.

Innovation Solution

The breaks between sinker cam segments are relocated to linear portions of the cam surfaces, where only frictional forces act, allowing smooth transition and reducing radial acceleration, thus reducing the angles of cam surfaces and facilitating high-speed operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If breaks between sinker cam segments are located at acceleration areas (crests and valleys), then the cam surfaces can be continuous, but the angles of cam surfaces must be increased and circumferential distance for sinker travel is reduced

Engineering Contradiction:
Improvecontinuity of cam surfacesVSAvoidoperational speed of knitting machine
Core Design Contradiction:
Stability of the object's compositionVSSpeed

Solution Approach 1:

The sinker cam is divided into multiple segments arranged edge-to-edge to form a complete cam ring. Each segment is independently designed with breaks positioned at linear portions rather than acceleration areas, allowing continuous operation while maintaining reduced cam surface angles for high-speed performance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cam segments feature curved cam surfaces that transition smoothly into linear portions. The breaks are positioned at these linear portions where the cam surface becomes substantially flat, eliminating the need for sharp transitions at acceleration points and enabling reduced cam angles for high-speed operation

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of manufacture

If breaks between sinker cam segments are located at acceleration areas, then the cam segments can be assembled edge-to-edge, but radial acceleration of sinkers is increased complicating high-speed operation

Engineering Contradiction:
Improveassembly of cam segmentsVSAvoidradial acceleration forces on sinkers
Core Design Contradiction:
Ease of manufactureVSForce

Solution Approach 1:

The cam ring is segmented into multiple identical or similar units that can be assembled edge-to-edge. Each segment incorporates a break at its linear portion, and when assembled, these breaks align to create continuous linear portions around the cam ring, maintaining low acceleration forces during high-speed operation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the cam segment serve different functions: curved portions provide smooth transitions while linear portions accommodate breaks with minimal acceleration. This local differentiation allows the break to be positioned optimally at the linear portion rather than at acceleration-critical curved sections

Inventive Principle:
Principle #3Local quality

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 enables smooth sinker movement and reduced acceleration requirements, enhancing the operational efficiency and speed of circular knitting machines by eliminating the need for linear portions at crests and valleys, allowing for more efficient stitch loop formation.

Implementation Method 1

the breaks are located in the linear portions of the working surfaces where substantially only frictional forces act on the sinkers

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2389468B1Circular knitting machine with sinker cams facilitating high-speed operation
Publication Date: 2015.04.01 MONARCH KNITTING MACHINERY CORP
  • EP2389468B1 patent drawingFigure 1
  • EP2389468B1 patent drawingFigure 2
  • EP2389468B1 patent drawingFigure 3

AI summary

A sinker cam ring for a circular knitting machine comprises a plurality of sinker cam segments arranged edge-to-edge to form the sinker cam ring, each sinker cam segment defining a portion of a sinker cam track that defines sinker-advancing and sinker-retracting surfaces. Breaks between adjacent sinker cam segments are located in linear portions of at least one of the sinker-advancing surfaces and sinker-retracting surfaces where substantially only frictional forces act on the sinkers, and thus where radial acceleration of the sinkers caused by the cam surfaces is substantially zero. The breaks for a given sinker cam segment can be circumferentially staggered relative to each other.