Patent drawings are generally drawn using Auto CAD or PRO/E. You can search and download these software on the website. Some particularly simple diagrams (flow charts, etc.) can be drawn using WORD, etc. It will be easier if you can use Auto CAD or PRO/E. If not, you can contact Changning Changqi Information. They specialize in patent drawings. Appearance and practical inventions can be used, as well as European and American hatched patent drawings