When a Blade is not a Knife
------------INVENTION ------------------------------------ ALLEGED INFRINGEMENT
On 23 December 2005, the Federal Court of Australia handed down Breville Pty Ltd v The Warehouse Group (Australia) Pty Ltd  FCA 1893 .
The applicant (Breville) sued the respondent (Warehouse) for infringement of its Australian patent no. 684615 for the invention entitled "Fruit and Vegetable Juicer".
Breville contended that Warehouse infringed, inter alia, claim 1:
A fruit and vegetable juicer of the kind comprising a horizontal grating disc rotatable about a vertical axis and integral with and surrounded by a substantially frusto-conical filter sieve the sides of which project upwardly and outwardly from the grating disk, a feed tube arranged above the disc and a food pusher insertable into the tube to press food down on to the grating disc for grating, pulp and juice thereby produced flying upwardly and outwardly, the juice passing through the filter and the pulp passing over the filter for subsequent collection characterised in that the feed tube has an internal diameter substantially the same as that of the grating disc, there being provided in the tube a knife or knives having an upwardly directed cutting edge, the knife or knives being attached to and supported by the tube, the food pusher being bifurcated or otherwise shaped to pass downwardly past the knife or knives, downward movement thereof causing an article of food to be cut by the cutting edge or edges of the knife or knives and pressed onto the grating disc, the food being held against rotation by the knife or knives.
The case turned on the proper construction of two aspects of claim 1, emphasized above.
According to the specification, " the pusher pushes ... on to the edge 18 which cuts it into two halves, which move downwardly on either side of the knife 17 and are then prevented from rotating and are pressed onto the grating disc 13 by downward pressure ..."
Lindgren J. referred to the questions posed to two witnesses in connection with the allegedly infringing device, known as a "Cascade Juicer". Lindgren J. held that the evidence did not establish that there was a technical meaning of any of the expressions in claim 1 and that they were to be given their ordinary meanings. Citing Allsop Inc v Bintang Ltd (1989) 15 IPR 686, his honour held that the construction of the specification is for the court.
Lindgren J. made reference to a number of dictionary definitions before deducing that "relevantly, in ordinary parlance, a knife necessarily has a blade with a sharpened edge designed for cutting."
His honour identified "the tension" that exists in cases of construction. First, there is the idea that a person should not be able to take the "pith and marrow" or "substance" of the patented invention and avoid infringement by avoiding the language of the claims. Secondly, there is the idea that the language of the patent claims has been chosen by the patentee, sets the boundary of the patentee's monopoly, and should not be extended by the court to catch that which the patentee has left open to be done by others.
The principle of construction has been referred to in my post entitled "Full Court Rules on Claim Construction". His honour was grateful for those references, but stated simply that the "blade" of the Cascade juicer was not "on any reckoning, "a knife ... having an upwardly directed cutting edge"". He reinforced this by setting out that the blade is not a "knife" as it does not have a sharpened edge designed to "cut". In fact, in this case, as his honour pointed out, the blade of the Cascade juicer had its "least sharp" edge facing upwards. Furthermore, his honour set out that if the blade were separated from the juicer, no one would contemplate using its upper edge for the purpose of cutting.
In view of this construction, Lindgren J. held that the Cascade juicer fell outside of claim 1 and therefore did not infringe the patent.
It is not clear why the claim was drafted so narrowly. However, this case is a reminder of the need for practitioners to think carefully about other embodiments which could achieve similar results. Perhaps a more favourable result would have been achieved if the relevant practitioner had referred to a "parting" or "splitting" member with suitable description in the specification explaining that an actual "cutting" edge could be replaced with a simple blade or vane.
In any event, this case emphasizes the importance of word selection and the ability to apply lateral thought when drafting patent documents.