Sewing Device for In-Line Fabric Attachment to Extrudates
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Solution Overview
Problem
Conventional sewing machines are not suitable for continuous, high-speed sewing of fabric onto extrudates in-line with the extrusion process due to their mechanically coupled and non-linear motion sequences, which disrupt the continuous conveying of the extrudate.
Innovation Solution
A method and device that utilize a sewing machine with a motor-driven cam disk to convert non-linear movement into a coordinated, constant-speed transport and needle movement, allowing for continuous and efficient sewing of fabric onto extrudates at the same speed as extrusion, using a servomotor to control the transport element and needle for uniform stitching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional sewing machines with mechanically coupled transport and needle movement are used, then sewing can be performed, but the continuous conveying of the extrudate is disrupted due to non-linear motion sequences
Solution Approach 1:
The sewing machine is divided into independently controllable components: the transport element (feed foot) and the needle device can be controlled separately through the cam disk mechanism. This allows the transport element to move the extrudate at constant speed while the needle device performs stitching motions, resolving the contradiction between sewing capability and continuous process flow.
Solution Approach 2:
The patent introduces a cam disk that converts uniform rotational motion into non-uniform linear motion for the needle device, while maintaining constant speed transport of the extrudate. This dynamic control mechanism enables the needle to perform stitching actions without disrupting the constant speed conveyance of the extrudate through the sewing machine.
2Productivity
If the extrudate is conveyed at constant speed through the sewing machine, then in-line processing is achieved, but conventional sewing machines cannot accommodate this due to their non-linear motion sequences
Solution Approach 1:
The cam disk acts as an intermediary mechanism between the uniform rotational motion of the drive source and the stitching requirements of the needle device. It mediates the motion transformation, allowing the extrudate to be conveyed at constant speed while the needle performs variable motion patterns required for sewing, thus enabling in-line processing with modified conventional sewing machines.
3Productivity
If high-speed sewing is performed on stiff extrudates, then productivity increases, but the non-linear motion of conventional sewing machines causes issues with stiff materials that cannot compensate for motion variations
Solution Approach 1:
The patent replaces the traditional mechanically coupled feed foot and needle mechanism with a cam disk-based control system that uses controlled non-uniform motion. This substitution allows the transport element to maintain constant speed for stiff extrudates while the needle device performs stitching motions through cam-converted non-uniform motion, achieving both high speed and high precision sewing on stiff materials.
Data Source
Figure 1
AI summary
The invention relates to a method for sewing woven fabric to an extrudate comprising at least the following steps: extruding the extrudate by means of an extruder at a constant process speed; conveying the extrudate from the extruder to a sewing machine at the constant process speed; sewing the woven fabric to the extrudate by means of the sewing machine at the constant process speed. The invention further relates to a sewing device and to a combined extruding and sewing device for sewing woven fabric to an extrudate.