Weaving Machine Back Rest Device Warp Tension Control
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Solution Overview
Problem
Existing back rest devices for weaving machines fail to provide reliable and consistent tensioning of warp threads, especially when weaving heavy fabrics, due to variations in warp thread consumption and angle, leading to inconsistent fabric quality.
Innovation Solution
A back rest device comprising a first guiding bar mounted in a fixed, non-rotatable position and a second guiding bar with a fixed longitudinal axis, arranged in parallel and upstream, which is rotatable to adjust the wrap angle and maintain consistent tension by using a supporting device with hooks and limit stops, ensuring reliable support even for less rigid guiding bars.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a back rest device uses a fixed guiding bar arrangement, then the device structure is simple, but the warp thread tension becomes inconsistent during weaving
Solution Approach 1:
The patent applies the dynamics principle by making the first guiding bar rotatable about its longitudinal axis, allowing it to change its angular position dynamically. This enables the wrap angle of warp threads around the guiding bar to be adjusted and maintained at an optimal value throughout the weaving process, ensuring consistent tension despite variations in warp beam diameter as threads are consumed.
2Weight of moving object
If the second guiding bar is made less rigid to reduce weight, then the device becomes lighter and easier to handle, but the guiding bar may deform under tension
Solution Approach 1:
The patent applies this principle by using a less rigid, lighter-weight second guiding bar that is still sufficient for its function of deflecting warp threads. The design accepts that the guiding bar will have some flexibility but ensures it maintains adequate structural integrity through appropriate material selection and cross-sectional design, achieving a balance between weight reduction and functional performance.
3Ease of operation
If the position of the second guiding bar is not fixed, then the device is easier to adjust for different weaving requirements, but the warp thread tension becomes inconsistent
Solution Approach 1:
The patent applies the feedback principle by using a supporting device with limit stops that provide mechanical feedback to the positioning system. The limit stops define specific angular positions for the first guiding bar, ensuring that the wrap angle and consequently the warp thread tension remain within optimal ranges. This feedback mechanism maintains tension consistency while still allowing adjustment between predefined positions.
Data Source
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AI summary
Weaving machine, method and back rest device for guiding warp threads (7) coming from a warp beam (10) comprising a first guiding bar (3), a mounting device (4), a second guiding bar(5, 105), which in use is arranged in parallel to the first guiding bar (3) and upstream of the first guiding bar (3) for deflecting warp threads (7) coming from the warp beam (10), and a supporting device (6), which for supporting the second guiding bar (5, 105) is arranged in use at least substantially fixed in position with respect to the longitudinal axis of the first guiding bar (3).