Method for thread trimming, thread loosening, presser foot lifting and presser foot pressure adjusting of sewing machine

Abstract

The invention relates to the technical field of sewing machines, in particular to a method for thread trimming, thread loosening, presser foot lifting and presser foot pressure adjusting of a sewing machine. A power piece drives a cam structure to rotate, a thread trimming driving section of a first driving contour face of the cam structure drives a thread trimming mechanism to execute thread trimming action, a thread loosening driving section of a second driving contour face of the cam structure drives a thread loosening mechanism to execute thread loosening action, a presser foot lifting driving section of the second driving contour face of the cam structure drives a presser foot lifting mechanism to execute presser foot lifting action, and a presser foot pressure adjusting driving section of the second driving contour face of the cam structure drives a presser foot pressure adjusting mechanism to execute presser foot pressure adjusting action. When current execution action is one ofthe thread trimming action, the thread loosening action, the presser foot lifting action and the presser foot pressure adjusting action, the other three actions are not generated or do not interferewith the current execution action. The four functions of thread trimming, thread loosening, presser foot lifting and presser foot pressure adjusting are achieved through the driving of the power piece.

Description

Technical field [0001] The invention relates to the technical field of sewing machines, in particular to a method for thread trimming and loosening of a sewing machine to lift a presser foot and presser foot pressure adjustment. Background technique [0002] At present, the sewing machine uses the thread trimming, thread loosening, presser foot lifting and presser foot pressure adjustment functions during the sewing process. Among them, the thread trimming function and the thread loosening function are realized by electromagnet drive, and there is a problem of slow response; the presser foot function is realized by hand-held, artificial knee, electromagnet, air cylinder and other driving methods, and when electromagnet is used, The presser foot lifting function and the thread trimming function are respectively driven by two electromagnets of different power; the presser foot pressure adjustment function is realized by manual adjustment of the pressure regulating nut. This drivin...

AI Technical Summary

Problems solved by technology

Among them, the thread trimming and thread loosening functions are driven by electromagnets, which has the problem of slow response; the function of lifting the presser foot is realized by driving methods such as hand-held, artificial knee rest, electromagnet, and cylinder, and when electromagnets are used, The presser foot lifting function and the thread trimming function are respectively driven by two electromagnets with different powers; the presser foot pressure adjustment function is realized by manual adjustment of the pressure regulating nut

This driving method to realize the four functions of thread trimming, thread loosening, presser foot lift and presser foot pressure adjustment has the disadvantages of complex structure and low working precision.

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