Determining the position function of sewing machine mechanisms using the triangle method

The quality of the stitches performed largely depends on the interaction of the working tools of sewing machines, so their exact location during the kinematic cycle is important. The location of the working tools is determined by the function of the position of the mechanism. The position function of the mechanisms is determined by analyzing their kinematic schemes. In practice, the method of closed vector contours and the triangle method are most widely used. The use of the closed vector contour method is not universal compared to the triangular contour method. The use of these methods for flat, kinematically complex sewing machine mechanisms makes it possible to develop universal programs by pre-distributing the component modifications of links and dyads into hierarchical structural modules and selecting and composing the main program from the prepared subprograms for them. The paper presents routines in the Python language, applied to the mechanism of the sewing machine 852 cl. At the same time, a structural diagram of the mechanism for modifications of links and dyadic groups is shown, which made it possible to develop a summary program for calculating the position functions of working tools and plot their graphs. The analysis of the calculated data will ensure the high-quality operation of the mechanism and the availability of working tools.