1. Apply for a new invention patent, but this invention can only protect the improved part of product A. You will have a utility model and an invention.
2. When the utility model is not authorized for the second time, and within 12 months after the application date of utility model, the priority of utility model can be claimed, so that the second application for invention patent can protect product A and its improved parts, and the first application for utility model will be regarded as withdrawal.