Weft Thread Clamping Plate for Loom Deflection Control
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Solution Overview
Problem
Existing weft thread feeding devices in weaving machines cause excessive deflection and waste of threads due to the need for catch bars and hard deflection mechanisms, which increase material requirements and lead to fabric defects.
Innovation Solution
A weft thread feeding device with a rotationally drivable color selection disk and clamping disk, where a reaching needle guides the active thread from the color selection disk to the clamping disk, allowing for smooth transfer to the gripper without deflection, and featuring actuators to open and close clamps for efficient thread handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a tack strip is used to hold weft threads in place, then the threads can be securely held, but the tack strip must be removed from the finished textile representing waste material and increasing fabric production material requirements
Solution Approach 1:
The invention extracts the thread-holding function from the tack strip and transfers it to the clamping device. The clamping device holds the weft threads in the clamping position without requiring any tack strip in the finished textile, thereby eliminating the waste material problem while maintaining secure thread holding throughout the weaving process
Solution Approach 2:
The tack strip is completely discarded from the process. Instead of being removed as waste, the holding function is permanently transferred to the clamping device which retains threads throughout the entire weaving cycle without becoming part of the finished product
2Productivity
If the feeder needle pushes or guides the weft thread downwards towards the gripper with sharp deflection, then the thread can be transferred to the gripper, but the sharp deflection potentially damages the thread
Solution Approach 1:
The invention replaces sharp angular deflection with a curved guiding path. The feed needle guides the thread along a curved trajectory from the clamping device to the gripper, distributing the directional change over a longer path and reducing stress concentration that would occur with sharp deflection
Solution Approach 2:
The feed needle is designed to gradually guide the thread into its final position rather than abruptly pushing it. This cushioning effect prevents sudden stress spikes that could damage the thread while still achieving efficient transfer to the gripper
3Adaptability or versatility
If multiple weft threads are held and inserted alternately using conventional devices, then color selection is possible, but excessive thread deflection and waste occur
Solution Approach 1:
The clamping device serves multiple functions: it holds multiple different colored weft threads, selects the required thread through rotation to bring it to the clamping position, and maintains the thread without deflection throughout the weaving process. This multi-functionality eliminates the need for separate tack strips and reduces thread waste while preserving color selection capability
Data Source
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AI summary
The invention relates to a weft thread supplying device for providing a plurality of weft threads in a loom and for selectively supplying an active weft thread to a gripper, having: a rotationally drivable colour selection plate with a plurality of eyelets arranged on its outer circumference, each for receiving at least one weft thread; a rotationally drivable clamping plate with a plurality of clamps arranged on its outer circumference, each for holding at least one weft thread when in its closed position; and a presenter needle arranged between the colour selection plate and the clamping plate, by means of which presenter needle the at least one active weft thread, from a presenting position in which the at least one active weft thread can be brought into a presenting rotational position by rotating the colour selection plate and an active clamp together with the clamping plate, can be delivered to the gripper in a delivery position, and the active clamp, following the delivery, is moved into an open position. The invention further relates to a loom having a weft thread supplying device of this kind.