When citing patents in a text (article, research paper, etc.), there
are different formats used, depending on the style of citation used. This
page lists some of the most common styles used when citing a patent and
gives examples of the citations.
Using the patent shown below as an example, here are citations using
various citation manual styles:
Williams, Dave. 2005. Screw less clip mounted computer drive. U.S. Patent
6,885,550, filed August 24, 2000, and issued April 26, 2005.
Williams, Dave. "Screw less clip mounted computer drive." Patent 6,885,550. 26 April 2005.
Williams, D. (2005). U.S. Patent No. 6,885,550. Washington, DC: U.S.
Patent and Trademark Office.

The
ACS Style Guide: Effective Communication of Scientific Information
(ACS Style Guide)
Williams, D. U.S. Patent 6,885,550, 2005.
IEEE (Institute of Electrical and Electronics Engineers 
Williams, "Screw Less Clip Mounted Computer Drive," U.S.
Patent 6,885,550, Apr. 26, 2005.
The Bluebook: A Uniform System of Citation (Eighteenth Edition)
U.S. Patent No. 6,885,550 (issued Apr. 26, 2005).
Williams D, inventor; 2005 Apr. 26. Screw less clip mounted computer drive. United States patent
US 6,885,550.
