Sewing Machine Cam Mechanism for Stable Cutting Needle Rotation
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Solution Overview
Problem
Existing sewing machines face challenges in ensuring smooth rotation of the cutting needle due to variations in member dimensions and assembly, leading to potential instability during horizontal movement of the needle bar.
Innovation Solution
A sewing machine design incorporating a needle bar driving mechanism, an embroidery frame movement mechanism, a cutting needle rotation mechanism, a processor, and memory, which uses a cam system to stabilize the cutting needle rotation by precisely positioning the needle bar and embroidery frame to ensure consistent contact and rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a specific gap is provided between the convex portion and the concave portion to prevent contact during cutting operation, then the cutting needle can perform cutting operation smoothly, but the cutting needle may not rotate smoothly due to variations in member dimensions and assembly
Solution Approach 1:
The patent employs a dynamic gap adjustment mechanism where the distance between the convex portion and concave portion is not fixed but can be adjusted. The control unit dynamically controls the positioning of the needle bar to adjust this gap based on operational requirements, allowing the system to adapt to dimensional variations while maintaining reliable rotation.
Solution Approach 2:
The patent changes the parameter of the gap distance between the convex and concave portions from a fixed value to a variable parameter that can be controlled. By using the control unit to adjust the needle bar position, the system can optimize the gap size to accommodate manufacturing tolerances and ensure smooth rotation despite dimensional variations.
2Extent of automation
If the convex portion engages with the concave portion to enable automatic rotation, then the cutting needle can rotate automatically during needle bar movement, but contact between the convex portion and concave portion may cause instability during cutting operation
Solution Approach 1:
The patent implements dynamic control of the engagement between the convex portion and concave portion. The control unit adjusts the needle bar position to enable engagement for automatic rotation during non-cutting phases, while maintaining a specific gap during cutting operations to prevent contact and ensure stability.
Solution Approach 2:
The patent employs periodic engagement and disengagement of the convex and concave portions. The system alternates between an engaged state (for automatic rotation) and a disengaged state with a specific gap (for stable cutting operation), creating a periodic action that switches between automation and stability requirements.
3Ease of operation
If the needle bar is moved in the horizontal direction to rotate the cutting needle, then automatic rotation is achieved, but variations in member dimensions and assembly may prevent smooth rotation
Solution Approach 1:
The patent incorporates a control unit that monitors the rotation status of the cutting needle and adjusts the needle bar position accordingly. This feedback mechanism ensures that the convex portion and concave portion maintain the appropriate relationship for smooth rotation, compensating for dimensional variations in real-time.
Solution Approach 2:
The control unit acts as an intermediary between the horizontal movement of the needle bar and the rotation of the cutting needle. It processes the movement input and adjusts the engagement between the convex and concave portions to ensure smooth rotation despite dimensional variations in the mechanical components.
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
The solution enables stable and automatic rotation of the cutting needle, improving the sewing machine's ability to perform cutwork by maintaining consistent cutting needle angle and reducing unnecessary rotation, thus enhancing the accuracy and stability of the cutting process.
Implementation Method 1
The cam member has a fixed cutting needle and comprises a plurality of cams arranged along the first direction and rotatable around the first direction. Each of the plurality of cams comprises a surface portion. The surface portion comprises a width along the first direction and is arranged in different positions along the first direction.
Data Source
AI summary
A sewing machine may comprise a needle bar driving mechanism, a cutting needle rotation mechanism, and an embroidery frame movement mechanism configured to move an embroidery frame comprising a protruding portion. A cam member may be fixed to the needle bar and comprise a plurality of cams. A processor of the sewing machine may set a height of the needle bar to a specific position from a plurality of positions. Each of the plurality of positions may represent that each of the plurality of cams is able to contact with the protruding portion. The processor may instruct the needle bar driving mechanism to move the needle bar to the specific position and instruct the embroidery frame movement mechanism to move the embroidery frame to a position where the protruding portion is able to contact with one of the plurality of cams.