Harvard

To be made up of:

• Inventor(s).
• Year of publication (in round brackets).
• Title (in italics).
• Authorising organisation.
• Patent number.
• Available at: URL.
• (Accessed: date).

In-text citation:
(Fredericks, 2012) 

Reference list:
Fredericks, F. (2012). Vinyl cleaning tool. UK Intellectual Property Office Patent no. GB2468906. Available at: http://www.ipo.gov.uk/p/find-publication (Accessed: 5 June 2013).