If you use assistive technology (such as a screen reader) and need a
version of this document in a more accessible format, please email firstname.lastname@example.org.
Please tell us what format you need. It will help us if you say what assistive technology you use.
Patent decision: O/085/91 in the matter of application under Section 13(1) for Patent no 2191914 by Ferguson Ltd dated 11 July 1991.