How to inquire about American invention patents?

I can post the patent number for you to check. You can also see if the patent number provided by the other party starts with a year, such as 2005. If so, it means that it is not authorized, that is, there is no patent. If it is seven digits, such as 5850457, it means that it has been authorized, that is, the patent exists. In addition, even if you are sure that this number is seven digits, it may not be a valid patent, and it may have expired or be unenforceable. In both cases, you need to inquire about the legal status of the patent.