There is a special kind of system in the American patent system called continuation Application and continuation-in-part. By extension, a patent family can often be created, and there can be "live and multiply from generation to generation". As long as the applicant's patented technology still has market value, it is necessary to take full advantage of the continuation patent  system to keep at least one case pending, so that there is an opportunity to modify the claims (CA) and add new subject matter in the Continuation-in-part case. In this way, there is always room for counterfeiters to greatly increase the difficulty of designing around the patent.