Filing an Assignment with a Patent Application
An assignment can be 
filed with a patent application to immediately convey control of the patent application to the assignee. This is frequently necessary where the inventor is an employee of a company that will be controlling the patent application. Only an inventor – a human – can be an applicant for a patent, not the company, so the inventor must be the initial applicant with a corresponding assignment conveying to the company thereafter. An assignment doesn’t need to be recorded with the USPTO to pass ownership of the patent application, but it must be on file to allow the company to control prosecution. The cleanest, simplest way of doing this is by drafting an assignment agreement, having the inventor and assignee-company sign it, notarizing it, and then recording it in the Patent Office at the time the application is filed.