Yarn Clamping Rod Ejection Prevention via Obstacle Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing yarn-clamping devices in weaving processes face issues with yarn ejection during clamping due to high tension, leading to irregular tension distribution and potential jamming, as seen in previous technologies like US-A-5 381 594 and EP-A-2 662 481.
Innovation Solution
A yarn-clamping device with a clamping rail and a non-circular cross-section clamping rod, featuring a movable obstacle that transitions from a retracted to a blocking position during the clamping rotation, preventing the clamping rod from moving out and ensuring stable yarn distribution without ejection, as described in the patent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rotating clamping bar with an elastic tube is used to clamp yarns, then the yarns can be blocked within the rail, but the tube and bar may be ejected from the clamping rail under high tension, causing the process to fail
Solution Approach 1:
The obstacle is made movable relative to the clamping rod, transitioning between a retracted position (allowing rod insertion and rotation) and a blocking position (preventing rod ejection). This dynamic adjustment allows the system to adapt during different phases of the clamping cycle, maintaining reliability while preventing harmful ejection.
Solution Approach 2:
The obstacle is positioned to prevent the clamping rod from moving in the extraction direction before the rod can be ejected by yarn tension. By establishing this counter-action in advance, the system prevents the harmful ejection effect from occurring.
2Ease of operation
If the clamping rod has a circular cross-section, then it can rotate freely, but it may move out of the clamping rail under high yarn tension
Solution Approach 1:
The clamping rod is given a non-circular cross-section (e.g., oval or rectangular) instead of a circular one. This asymmetric shape allows the rod to rotate within the clamping rail while the dimensions are carefully chosen so that the rod can be inserted (when its smallest dimension fits through the opening) but cannot be ejected (when its largest dimension is larger than the opening width).
Solution Approach 2:
The cross-sectional dimensions of the clamping rod are specifically designed to change its geometric parameters: the first external dimension (smallest) is made smaller than the opening width for insertion, while the second external dimension (largest) is made larger than the opening width to prevent ejection. This parameter optimization resolves the contradiction between rotation freedom and retention.
3Reliability
If the obstacle blocks the clamping rod rotation, then ejection is prevented, but the rod cannot be inserted or repositioned
Solution Approach 1:
The obstacle's position is made dynamic rather than fixed. It can retract to allow rod insertion and rotation, then move to a blocking position to prevent ejection. This dynamic behavior allows the system to satisfy both requirements at different times in the operational cycle.
Solution Approach 2:
The obstacle retracts beforehand to create space for rod insertion and initial rotation movements. Only after the rod is properly positioned does the obstacle move into the blocking position to prevent ejection, ensuring that insertion is not hindered.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A yarn-clamping device (20) includes a clamping rail (22), a clamping rod (24), configured to be inserted into a clamping volume, the clamping rod (24) having a clamping rotation movement relative to the clamping rail (22), in a clamping direction (R2), from an insertion position to a clamping position. The yarn-clamping device also includes at least one maintaining device (26) comprising an obstacle (90) configured to have a movement relative to the clamping rod, from a retracted position to a blocking position during the clamping rotation movement of the clamping rod. The retracted position of the obstacle corresponds at least to the insertion position of the clamping rod, whereas the blocking position of the obstacle corresponds at least to an intermediate position relative to the clamping rail (22), reached by the clamping rod in its clamping rotation movement, shifted with regard to the insertion position. The obstacle prevents a rotation movement of the clamping rod within the clamping volume in a direction (R3) opposite to the clamping direction.