Rapier Loom Weft Insertion Device Yarn Guide Mechanism
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Solution Overview
Problem
Existing weft insertion devices for rapier looms have complex structures that can negatively affect high-speed reciprocating motion and increase the likelihood of failure in gripping flat yarns, leading to issues like warp breakage and excessive yarn consumption.
Innovation Solution
A simplified weft insertion device with a rapier head that includes a yarn guide mechanism and an operation lever with a swinging motion to grip and insert flat yarns, reducing the complexity of the gripping mechanism and minimizing interference with the rapier band, thereby stabilizing high-speed reciprocation and reducing yarn waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a complex gripping mechanism with multiple gripping portions is used to grip flat yarn, then the yarn can be securely held, but the device structure becomes complex and high-speed reciprocating motion is affected
Solution Approach 1:
The gripping mechanism is divided into two functional parts: a fixed gripping surface formed by the head body and a movable gripping portion that displaces to grip the yarn. This segmentation allows the fixed part to provide stable support while the movable part provides the gripping action, simplifying the overall structure compared to having multiple complex gripping portions.
Solution Approach 2:
The invention extracts only the essential gripping function from a complex multi-component mechanism. By using a single movable gripping portion that works in conjunction with a fixed gripping surface, the patent removes unnecessary components while maintaining reliable yarn gripping capability.
2Object-affected harmful factors
If the second gripping portion is swung to avoid interference with flat yarn during rapier head advancement, then interference is prevented, but the mechanism complexity increases
Solution Approach 1:
The movable gripping portion is positioned and configured in advance to avoid interfering with the flat yarn during the rapier head's advancement phase. By pre-positioning the gripping portion appropriately and using a simple swinging motion only when needed for gripping, the invention prevents yarn interference without requiring complex multi-stage mechanisms.
3Ease of operation
If a complex operation system with multiple gripping portions is used, then yarn gripping can be achieved, but the likelihood of failure in gripping flat yarn increases
Solution Approach 1:
The movable gripping portion is designed to automatically engage with the flat yarn through its displacement mechanism, reducing the need for complex control systems and multiple gripping portions. This self-acting mechanism improves reliability by eliminating potential failure points associated with complex multi-component operation systems.
4Adaptability or versatility
If the rapier head structure is complex, then yarn gripping function is achieved, but high-speed reciprocating motion is negatively affected
Solution Approach 1:
The movable gripping portion is designed to displace dynamically during the reciprocating motion of the rapier head, enabling yarn gripping without requiring a statically complex structure. This dynamic approach allows the rapier head to maintain simplicity for high-speed reciprocation while still providing effective yarn gripping capability.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A weft insertion device (1) for a rapier loom includes a yarn guide mechanism (50) including a holding device (51) that holds a tip portion of the flat yarn (Y) and that guides the flat yarn (Y) from a position above a movement path (P) of the rapier head (10, 10') to a position below the movement path (P) with respect to an up-down direction, the yarn guide mechanism (50) displacing, independently or in cooperation with the rapier head (10, 10'), the flat yarn (Y) in a direction parallel to a width direction of the rapier head (10, 10'). Immediately before weft insertion is started, the flat yarn (Y) is guided into a yarn inlet portion (11d, 11d') of the rapier head (10, 10') while the flat yarn (Y) is displaced by the yarn guide mechanism (50) in the width direction of the rapier head (10, 10').