Automated Feed Ratio Control for Differential Feed Sewing Machines
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Solution Overview
Problem
In differential feed sewing machines, setting the feed amounts of the auxiliary and upper feed dogs relative to the main feed dog is difficult, making it challenging to produce clothes with desired designs without trial and error.
Innovation Solution
A differential feed sewing machine equipped with a controller that calculates and controls the feed amounts of the auxiliary and upper feed dogs based on sewing data, including fabric lengths and target finished lengths, ensuring precise fabric feeding operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual trial and error adjustment is used to set feed amounts, then the sewing machine can operate with simple controls, but it requires excessive time and cannot achieve precise feed amount settings
Solution Approach 1:
The patent replaces manual mechanical adjustment of feed amounts with an automated calculation system. The controller computes optimal feed amounts for the auxiliary and upper feed dogs based on sewing data (lower fabric length, upper fabric length, and finished length), eliminating the need for operators to manually adjust settings through trial and error.
Solution Approach 2:
The sewing machine performs self-adjustment by automatically calculating and setting the feed amounts based on the input sewing data. The system determines the appropriate feed amounts for auxiliary and upper feed dogs without requiring external manual intervention, thereby reducing adjustment time while maintaining precision.
2Measurement precision
If automated calculation of feed amounts is implemented, then feed amount setting precision is improved, but the device complexity increases due to additional controller functions
Solution Approach 1:
The controller performs multiple functions: it stores sewing data (lower fabric length, upper fabric length, finished length), calculates optimal feed amounts for auxiliary and upper feed dogs, and controls the feeding operations of all three feed dogs. By consolidating these functions into a single controller, the patent avoids the need for separate adjustment mechanisms for each feed dog.
Solution Approach 2:
The patent combines the data storage, calculation, and control functions into an integrated controller system. Rather than having separate mechanisms for storing sewing parameters, calculating feed amounts, and controlling each feed dog independently, the system merges these functions into one unified controller that manages all operations based on the input sewing data.
Data Source
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AI summary
The differential feed sewing machine (1) includes a main feed dog (11) configured to feed a lower fabric (41), an auxiliary feed dog (12) configured to feed the lower fabric (41), an upper feed dog (13) configured to feed an upper fabric (42), and a controller (20). The controller (20) includes a sewing data obtaining unit (21) configured to obtain sewing data including a lower fabric length (Ld), which indicates a length of the lower fabric (41), an upper fabric length (Lt), which indicates a length of the upper fabric (42), and a finished length (Lm), which indicates a target value of a length of a sewn product (43) after the lower fabric (41) and the upper fabric (42) are sewn. The controller (20) also includes a calculation unit (23) configured to calculate a feed amount of the auxiliary feed dog (12) and a feed amount of the upper feed dog (13) relative to a feed amount of the main feed dog (11) based on the sewing data. The controller (20) also includes a control unit (24) configured to control respective feeding operations of the main feed dog (11), the auxiliary feed dog (12), and the upper feed dog (13) based on the feed amounts calculated by the calculation unit (23).