As mentioned previously, ownership is altogether different than inventorship.

The ownership of a patent or a patent application is always held by the inventors unless they have "assigned" it over to another party. Even patents may be bought and sold just like any other type of property (be it real estate or an automobile). These assignments or transfers of ownership may be made to an individual or to a corporation.

Whomever the assignment is made to is called the assignee. If all the patent rights are assigned, the inventor(s) may lose all their privileges to the patent, even mere access to it. Non-inventors may even file an application if the invention is assigned to him or her. 

Assignments may be made as the application is sent in, during the application's examination or after it has been allowed to issue as a patent. Regardless of when they are made, assignments must be recorded with the PTO in order to be recognized by the PTO. If there is no recordation of the assignment by the PTO, it is assumed that none exists, which may cause trouble down the road.

The inventor will always be considered the owner of the patent rights unless there is a recorded assignment.

The information necessary to record an assignment consists of a cover sheet and a fee. The cover sheet must include the identifying information concerning the assignee of the patent. For example, the application or patent number along with the filing date must be supplied. If the assignment is made before the patent is allowed to issue, the assignee will automatically be listed on the patent. However, if an assignment is made after the patent issues, the assignee will have to file a petition in order to be listed on the patent as an assignee.