| 摘要 |
Disclosed are a crank rod and a method for changing and selecting the model of a sewing machine by adjusting the vertical movement trajectory of a needlebar on the sewing machine. The present invention comprises the steps of: identifying the model of a sewing machine; removing a crank rod applied to the model of sewing machine that has been identified in the previous step, and selecting a crank rod that is longer or shorter in length compared to the removed crank rod; installing the crank rod selected in the previous step on an upper shaft of a sewing machine arm; and guiding adjustment of the vertical movement trajectory of the needlebar through the crank rod installed on the upper shaft in the previous step, thereby guiding a change of sewing machine model and providing a selection of models in a single sewing machine. |
