Compound Needle Elastic Snap-Fit Joining for Flatbed Knitting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing compound needles for flatbed knitting machines require a post-process to strongly fix the joining part between the slider and the base body, which is inefficient and prone to removal of components due to bending moments.
Innovation Solution
A compound needle design featuring a concave part with a narrowing section and a convex part with a widening section, allowing for elastic deformation and secure joining without the need for post-processing, where the concave part is inserted into the convex part's groove, ensuring a stable connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the joining part between slider and base body is designed with simple insertion structure, then assembly is easy, but the connection is not strong enough and components may come off due to bending moments
Solution Approach 1:
The joining part incorporates an elastic blade that can dynamically deform under bending moments. The blade is designed to elastically bend when subjected to lateral forces during knitting operations, absorbing the bending moments without causing component failure. This dynamic response allows the simple insertion structure to maintain both ease of assembly and sufficient connection strength.
Solution Approach 2:
The blade's width is specifically designed to be 3mm or less, creating a narrow profile that allows easy insertion into the needle groove while maintaining sufficient structural integrity. The dimensional parameter of the blade (width ≤ 3mm) is optimized to balance between assembly ease and connection strength, allowing the joining part to resist bending moments during operation.
2Strength
If the joining part is strongly fixed with post-processing, then connection strength is improved, but manufacturing complexity and time increase
Solution Approach 1:
The joining part is designed to be self-fixing through the elastic blade's inherent properties. When the blade is inserted into the needle groove and subjected to bending moments during knitting operations, it naturally deforms and locks into position, providing strong fixation without requiring any post-processing steps. The elastic deformation of the blade during normal operation serves as the self-service mechanism that secures the connection.
Solution Approach 2:
The design extracts the complex post-processing fixation steps from the manufacturing process entirely. By incorporating the elastic blade with width ≤ 3mm that can be simply inserted and then self-secured through elastic deformation during operation, the invention removes the need for additional fixation operations such as welding, threading, or adhesive application, thereby simplifying the manufacturing process while maintaining connection strength.
3Strength
If the blade width is increased to prevent coming off, then connection strength is improved, but the blade cannot be inserted into the narrow needle groove
Solution Approach 1:
The blade width is optimized to be 3mm or less, creating a narrow profile that fits within the needle groove dimensions. This dimensional parameter is carefully selected to balance two competing requirements: being narrow enough for easy insertion into the groove while being sufficiently wide to provide adequate retention strength through elastic deformation. The parameter optimization allows the blade to satisfy both constraints simultaneously.
Solution Approach 2:
Rather than increasing blade width statically to improve retention, the design uses dynamic elastic deformation of the narrow blade (width ≤ 3mm) to achieve retention strength. The blade's ability to elastically bend and recover during knitting operations provides the retention mechanism, eliminating the need for increased width. The dynamic elastic response compensates for the narrow cross-sectional dimensions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design eliminates the need for post-processing to strongly fix the slider to the base body, providing a secure and stable connection that prevents the opening and closing body from coming off, while allowing for easy assembly and disassembly.
Implementation Method 1
The concave part is elastically deformed midway through insertion in the vertical direction, and the widening part is allowed to pass through the narrowing part, so that it is possible to join the opening and closing body to the base body at the joining part
Data Source
Figure 1(a)~1(b)
Figure 2(a)~2(d)
Figure 3(a)~3(e)
AI summary
[Problem to be solved] There is provided a compound needle for a flatbed knitting machine with no need to strongly fix a joining part as a slider in post-process operations. [Solution] An upper joining part (11c) of a base body (11) shown in (a) is joined to lower joining parts (12c, 13c) of the blades (12, 13) to form a joining part (15) shown in (b). Concave parts (12d, 13d) are respectively provided with narrowing parts (12e, 13e) in which the width between side walls is narrower than the width of an opening, and a convex part (11e) is provided with a widening part (11g) having the wider width than that of the narrowing parts (12e, 13e). The concave parts (12d, 13d) are elastically deformed midway through the insertion in the vertical direction, and the widening part (11g) is allowed to pass through the narrowing parts (12e, 13e). Thus, it is possible to join the two blades (12, 13) to the base body (11) as similar to the snap fitting of synthetic resin products. A groove (11d) provided at the tip end of the convex part (11e) sandwiches the blades (12, 13) below the concave parts (12e, 13e), so that it is possible to prevent the blades (12, 13) from coming off in the plate thickness direction.