Flat Knitting Machine Movable Sinker Yarn Nip Prevention
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Solution Overview
Problem
In flat knitting machines with both fixed and movable sinkers, high yarn tension can cause the movable sinker to bend, creating a gap between the sinkers where the knitting yarn can be nipped, leading to inhibited movement and reduced fabric quality, especially in fine gauge machines where the yarn is thin.
Innovation Solution
The design includes a projecting portion on the movable sinker positioned closer to the swinging center than the yarn receiving portion, which extends further towards the operating direction and is interposed between the yarn receiving portion and the yarn holding wire, preventing yarn nip even if the sinker bends, and is configured to remain within the contour of the fixed sinker's range to avoid inhibiting stitch formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the movable sinker is made thin to reduce interference with the knitting yarn, then the ease of operation is improved, but the strength is reduced causing the sinker to bend under high yarn tension
Solution Approach 1:
The movable sinker is divided into multiple functional portions: a thin distal end portion (51) for non-interference with yarn, an intermediate portion (50) for structural support, and a proximal end portion (52) for actuation. This segmentation allows each portion to be optimized independently - the distal end remains thin for ease of operation while the intermediate portion provides bending resistance.
Solution Approach 2:
Different portions of the movable sinker have different thicknesses tailored to their specific functions. The distal end portion has minimal thickness to avoid yarn interference, while the intermediate portion has increased thickness to provide structural strength and prevent bending under tension, creating local quality variations that resolve the contradiction.
2Adaptability or versatility
If the movable sinker is made thinner for fine gauge knitting, then the adaptability is improved, but the reliability is reduced as the yarn is easily nipped in gaps when the sinker bends
Solution Approach 1:
The knitting yarn receiving portion (5B) and projecting portion (5C) are positioned in advance to intercept and guide the knitting yarn before it can be nipped in gaps. The receiving portion makes contact with the yarn first, and the projecting portion creates a protective barrier, preventing the yarn from entering the gap between sinkers even when bending occurs.
Solution Approach 2:
The projecting portion (5C) acts as an intermediary element between the movable sinker body and the knitting yarn. It extends into the potential gap area to prevent direct contact between the yarn and the gap, serving as a protective mediator that maintains reliability while allowing the sinker to remain thin for fine gauge work.
3Ease of operation
If the movable sinker is swung to push down the sinker loop, then the ease of operation is improved, but the manufacturing precision is reduced as stitch decision accuracy decreases
Solution Approach 1:
The sinker system is segmented into two distinct components: the fixed sinker (4) dedicated to stitch decision with high precision, and the movable sinker (5) dedicated to sinker loop control. This segmentation allows each component to be optimized for its specific function without compromise.
Solution Approach 2:
The fixed sinker and movable sinker are combined in a single system where they work cooperatively. The fixed sinker provides precise stitch decision while the movable sinker provides flexible loop control, merging the advantages of both immovable precision and movable adaptability to resolve the contradiction.
Data Source
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AI summary
There is provided a flat knitting machine in which the knitting yarn is less likely to be nipped between a fixed sinker and a movable sinker. The flat knitting machine includes a fixed sinker 4 and a movable sinker 5. Assuming a direction from an inoperative position, where the movable sinker does not make contact with a sinker loop, to an operative position, where the movable sinker makes contact with the sinker loop, in a swinging direction of the movable sinker 5 is an operating direction, the movable sinker 5 includes a projecting portion 5C at a position closer to a swinging center than a knitting yarn receiving portion 5B when seen from the swinging center of the movable sinker 5. The projecting portion 5C is projected out more toward the operating direction than the knitting yarn receiving portion 5B. When a virtual line connecting a holding point of the knitting yarn 8 in the hook 3F when the knitting yarn 8 is pulled in with the hook 3F of the knitting needle 3 and a holding point of the knitting yarn 8 in the fixed sinker 4 is defined, the projecting portion 5C when the movable sinker 5 is arranged at the inoperative position is arranged on an upper side of the needle bed 2 than the virtual line.