Weft Insertion Device Yarn Guide Mechanism
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Solution Overview
Problem
Existing weft insertion devices for rapier looms face issues with damaging flat yarns due to high tension and sliding resistance, leading to decreased fabric quality and unreliable yarn holding during weft insertion.
Innovation Solution
A weft insertion device with a yarn guide mechanism that includes a holding device with a guide plate and a grip-driving device, which guides the flat yarn from above the rapier head's movement path to below it, reducing sliding contact and tension, and ensures accurate holding of the yarn for reliable insertion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the flat yarn is pulled out during weft insertion with the existing yarn guide mechanism, then the weft insertion can be performed, but the high tension and sliding resistance cause yarn damage and decrease fabric quality
Solution Approach 1:
The patent introduces a yarn guide mechanism as an intermediary component between the weft supply and the rapier head. This mechanism includes a guide plate and guide member that actively guide the flat yarn through the shedding, reducing the sliding resistance and tension that would otherwise act directly on the yarn during insertion.
Solution Approach 2:
The patent changes the spatial arrangement by positioning the yarn guide mechanism at a specific location and orienting the guide plate and guide member to provide a more favorable insertion path. This dimensional optimization reduces the harmful friction and tension forces during yarn insertion.
2Ease of operation
If the flat yarn is guided at a position above the movement path of the rapier head, then the yarn can be supplied, but the yarn cannot be held reliably for accurate insertion
Solution Approach 1:
The yarn guide mechanism performs preliminary guidance of the flat yarn before it reaches the rapier head. The guide plate and guide member pre-position the yarn in the correct orientation and location, ensuring that when the yarn is transferred to the rapier head, it is already in the optimal state for reliable holding and accurate insertion.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A weft insertion device (1) includes a yarn guide mechanism (50) that includes a holding device (51) including a holding body that is disposed below the movement path (P) and holds a flat yarn (Y), a guide device (55) that is disposed above the holding device (51) and guides a tip portion of the flat yarn (Y) to the holding device (51), and a guide member (53) that guides the flat yarn (Y) at a position above the movement path (P). The guide device (55) includes a guide plate (55a) that is disposed directly above the holding body so as to be perpendicular to a weaving width direction and a guide-plate driving device (55g) that displaces the guide plate (55a) between an upper standby position above the movement path (P) and a guide position where an end of the guide plate (55a) reaches the holding body.