Sewing Machine Threading Device with Multi-Axis Cam Positioning
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Solution Overview
Problem
Existing sewing machines with multiple needles, especially those implementing complex stitch patterns like overlock and cover stitches, face difficulties in guiding a threading hook to each needle due to varying needle heights and non-linear arrangements, making it challenging to perform accurate threading operations.
Innovation Solution
A threading device with a positioning mechanism that includes a combination of first and second cam mechanisms and supporting mechanisms allowing the threading shaft to move in both horizontal directions, enabling precise positioning of the threading hook relative to each needle, even when needles are not arranged in a simple linear fashion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a threading device with a single threading shaft is used for multiple needles arranged in complex patterns, then the device complexity is reduced, but the positioning precision and ability to reach each needle eye deteriorates
Solution Approach 1:
The patent applies dynamics by making the threading shaft movable in multiple directions through cam mechanisms. The threading shaft can dynamically adjust its position in the horizontal direction (parallel to needle bar) and vertical direction (perpendicular to needle bar) to reach different needle eyes, transforming a static single-point threading device into a dynamic multi-position system.
Solution Approach 2:
The patent transitions from one-dimensional linear needle arrangement handling to two-dimensional complex pattern handling by adding movement capabilities in both horizontal and vertical directions. The threading shaft operates in a two-dimensional space to accommodate needles arranged in complex patterns, not just simple linear sequences.
2Adaptability or versatility
If the threading shaft is made movable in multiple directions to reach all needles, then the positioning capability improves, but the device complexity and mechanism complexity increase
Solution Approach 1:
The patent segments the positioning function into two independent cam mechanisms: one for horizontal movement (parallel to needle bar) and one for vertical movement (perpendicular to needle bar). Each cam mechanism handles one dimension of positioning, dividing the complex two-dimensional positioning task into simpler, manageable one-dimensional movements.
Solution Approach 2:
The threading shaft serves multiple functions by being capable of moving in both horizontal and vertical directions to thread different needles. The same threading shaft structure is used universally for all needles regardless of their position, eliminating the need for separate threading mechanisms for each needle.
3Measurement precision
If cam mechanisms are used to control threading shaft movement, then the positioning accuracy improves, but the device complexity increases
Solution Approach 1:
The patent introduces cam mechanisms as intermediary elements between the operation lever and the threading shaft. The cams translate the operator's lever movement into precise controlled movements of the threading shaft in both horizontal and vertical directions, acting as mediators that convert simple input motion into complex coordinated output motion.
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
Enables accurate and efficient threading of multiple needles by allowing the threading shaft to be positioned correspondingly to each needle's arrangement, ensuring proper thread insertion across all needles, even in complex configurations.
Implementation Method 1
a first cam mechanism from which a movement in the first direction is given to the threading shaft in accordance with an operation of the movement operating portion
Implementation Method 2
a second cam mechanism from which a movement in the second direction is given to the threading shaft in accordance with an operation of the movement operating portion
Data Source
AI summary
A threading device includes a threading shaft holding a threading hook, a threading operation inputting mechanism from which a back-and-forth movement is given to the threading hook, a first supporting mechanism movably supporting the threading shaft in an X-axis direction, a second supporting mechanism movably supporting the threading shaft in a Y-axis direction, and a positioning mechanism which, when a movement operating portion is operated, moves the threading shaft along a path corresponding to an arrangement of each of the needles. The positioning mechanism includes a first cam mechanism which moves the threading shaft in the X-axis direction, and a second cam mechanism which moves the threading shaft in the second direction. The threading shaft is sequentially moved to positions corresponding to the arrangement of each of the needles in the horizontal directions in accordance with the operation of the movement operating portion.