Sewing Machine Top Feeder Pressure Control Mechanism
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Solution Overview
Problem
Existing top feeders in sewing machines lack the ability to adjust pressure manually or maintain a predetermined pressure, leading to suboptimal sewing results due to varying cloth thickness and material properties, and can interfere with the user when not in use.
Innovation Solution
A top feeder system with a vertically movable presser bar and a boomerang lever mechanism, allowing manual adjustment of pressure through a sleeve member and resilient member, and automatic regulation using a sensor and stepping motor to maintain consistent pressure despite cloth thickness variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a kinematic connection between the presser bar and top feeder is used to control movements, then the top feeder movements are synchronized with sewing machine cyclic movements, but the top feeder cannot be easily adjusted or removed and may interfere with the user when not in use
Solution Approach 1:
The top feeder is designed with dynamic characteristics, allowing it to be swung away from the working position when not in use. The lifting drive mechanism enables the top feeder to be raised and lowered, providing both synchronization during operation and accessibility when idle, thus resolving the contradiction between reliability and ease of operation
2Device complexity
If a fixed spring pressure is used on the top feeder, then the structure is simple, but the pressure cannot be adjusted for different cloth types and thicknesses
Solution Approach 1:
The spring pressure parameter can be adjusted by changing the position of the spring or selecting different spring constants. This allows the top feeder to adapt to different cloth types and thicknesses while maintaining a relatively simple structure, resolving the contradiction between device complexity and adaptability
3Manufacturing precision
If the top feeder pressure is increased to prevent shearing of low friction cloth, then feeding improvement is achieved, but marks may be created on thin pieces of cloth
Solution Approach 1:
The spring pressure parameter can be adjusted to optimize the balance between preventing shearing and avoiding marks on thin cloth. By changing the pressure parameter according to the specific cloth being sewn, both contradictory requirements can be satisfied
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 precise control of top feeder pressure, improving cloth feeding during sewing by adapting to different cloth densities and thicknesses, preventing shearing or marking, and ensuring consistent seam quality.
Implementation Method 1
a resilient member (20) at its lower end attached to said first attachment point, and at its upper end attached to a second attachment point (21) of said dog member (15)
Data Source
AI summary
A top feeder arrangement for a sewing machine provided with a processor for controlling stitches sewn on a cloth, wherein the sewing machine has a sewing machine head which comprises a needle mechanism with a needle bar (1) provided with a needle (2), a presser bar (3) provided with a presser foot (4) and a top feeder arm (10) provided at its lower end with a top feeder (11) acting from an upper surface of a cloth for feeding the cloth in the sewing direction and wherein the sewing machine is provided with a mechanism (12, 15, 17, 18) providing a controllable pressure of the top feeder (11) against the cloth.