Patent Infringement Case - “ZIPS SCREWS”

This is not a celebrity scandal involving articles of clothing but a recent case in the Australian Federal Court involving a patent for “Zips screws”. This is a screw used for joining sheet metal to timber. The Patentee who was the Applicant in the case alleged that Loi and Tran Pty Ltd, the Respondents, had infringed their patent. The Respondents denied infringement and alleged that the patent was invalid.

Zips screws were developed to overcome deficiencies in existing screws. Specifically, earlier screws were suitable for drilling sheet metal or timber, not both. The earlier metal screws have a drill-like trip which is untapered at the end. This tip is for cutting through metal and is unsuitable for wood because the screws are not threaded right to the end. In contrast, existing wood screws are threaded right to the end and have a taper to draw the screw into the wood. These wood screws, if used in metal, produce burrs which impede the functioning of the screw. The patented ‘Zips screws’ combined features of both prior art screws.

Claim 1 of the patent defined a screw for fastening sheet metal to timber with a number of features. The most important feature in terms of the litigation was that defining a shank tapering to a drilling tip.

The Respondents’ screws were developed independently for the same purpose as for patented screw. Importantly, the Respondents’ screws had no visible taper. Independent testing submitted in evidence showed a minuscule degree of taper in the Respondents’ screws. The taper amounted to hundredths of a millimetre.

The Judge found that the Patentee failed to establish that the Respondents’ screws had a taper that performs any function at all. Specifically the Judge applied the Improver v Remington Guidelines which require if there is a variant that has a material effect on the way an invention works, the article will be deemed not to infringe.

In considering the case the Judge found that the “tapering” to said “drilling tip” in Claim 1 should not be construed literally but should be understood by focusing on the purpose or function of the taper. In this context “tapering” should be interpreted as any narrowing in the shaft that serves to draw the screw in. The Judge found that the Respondents’ screws cannot be said to have the tapering as required by Claim 1. Although the patentees missed out in terms of infringement at least the invalidity attack on the patent was unsuccessful.

ITW AFC Pty ltd v Loi and Tran Pty Ltd [2008] FCA 552 (23 April 2008), Federal Court of Australia, Finkelstein J

If you would like any further information in relation to this article, please do not hesitate to contact Julie Harkins