THE ANALYSIS OF THE INTERACTION OF WORKING BODIES THROUGH STUDYING THE CYCLORAMA OF THE SEWING MACHINE

Abstract

In a sewing process, there is a close interaction between several factors: the working parts of the sewing machine which are actioned by an electric drive, the material (type, number of layers, the relative position of the layers) with different parts of the sewing machine and the worker (level of qualification). The result of this complex interaction is the seam. A good correlation between the working parts of the sewing machine determines a good seam, which is visible when one inspects the aspect of the garment. It is important for a clothing engineer to understand the mechanisms of a sewing machine (how they should work, as well as the correlation between their movements), because the final result (the seam) must fulfil the quality requirements. The interactions between the working parts of the sewing machine are analysed by taking into consideration the stages of the stitching process and the cyclorama of the sewing machine. A cyclorama is a graphical representation of the correlation between the active routes between all of the components of the sewing machine involved in the stitching process. The active route of a working part (component) involved in the aforementioned process is defined as the time it needs to make a complete movement (a point placed on the component describes a complete trajectory). The active work part rate is the time in which the machine part takes part in the stitching process and it is determined by the rotation angle of the main shaft (or the flywheel) measured from the moment when the working part gets involved in the process until the one it ceases to be so. In this paper, the authors present the stages of designing the cyclorama of a sewing machine used in evaluating if it is working properly or not. If they are provided with video tutorials, the students will be able to understand the moments in which the components of the sewing machines become involved in the process and the ones in which they cease to do so, their role in the process of sewing, as well as the relative positions of the working parts at specific moments. The cyclorama is useful in determining the angles of rotation of the main shaft corresponding to the active races of each working part.