Feeding mechanism and durability of differential lockstitch sewing machine

As a machine with differential structure added to the lockstitch sewing machine, its mechanism naturally has the function of adjustable differential feeding. according to different models and specifications of differential lockstitch machines, each model must have the adjustable function of upper differential or lower differential. Some adopt electronic adjustment, and some adopt mechanical adjustment.

Sewing is the process of sewing two or more layers together. affected by the resistance of the foot press cloth and the take-up resistance of the upper and lower seams, the sewing process is very easy to cause sewing problems such as shrinkage, clothing, twisting and striking.

Due to the diversity of fabrics, such as elastic fabrics, throwing materials (down, cotton clothes), high count cotton, etc., the above problems can not be solved by adjusting the fabric feeding mechanism, pressure regulation, and take-up and take-off mechanism to the best synchronous state. This requires the differential adjustment function to solve the feeding problem of the upper fabric or the lower fabric.

The differential adjustment includes not only the stroke adjustment of the feeding presser foot or the stroke adjustment of the lower differential tooth but also the adjustment of the feeding phase (sequence) of the feeding presser foot and the lower differential tooth, that is, what people usually say is to grasp the material in advance or delay the pulling of the material, so as to meet the requirements of flatness and beauty of various fabrics after stitching. Some machines do not have the function of feeding phase adjustment, but the manufacturer has marked the "differential" function on the product promotional materials. Consumers should be careful not to be misled!

Durability is the most important index for the quality stability of lockstitch sewing machines, it is also the index that users care most about. Generally, the user's factory will require the machine to be used for more than a week, and it is considered as the initial judgment that the quality is relatively stable. At present, there is no industry standard for the durability of sewing machines. The quality improvement project in the sewing machinery industry has the following testing methods and requirements for durability: run at the maximum sewing speed for 3 seconds and stop for 1 second. After 500 hours of continuous operation, there should be no major defects such as parts falling off, locking, oil leakage, abnormal noise, etc.

In the daily quality inspection work, some products will encounter E14 shutdown failure a few hours after the test, accompanied by the phenomenon of increased torque, and some machines will lock the pressure bar after running in for a certain hour, resulting in the inability of the presser foot to move up and down.

As a high-end lockstitch sewing machine gradually formed and applied in China in recent years, the application scope of differential lockstitch machines is becoming wider and wider, which is the trend of updating lockstitch sewing machines. We will continue to track and report on the subsequent development of this field.