Chemical manufacturer Quaker own two patents relating to a method for detecting high pressure fluid injection (“HPFI”) injuries.
When a small crack occurs in a tube carrying hydraulic fluid at high pressure, a fine stream of liquid can inject itself into a person’s body. The resultant injuries are often difficult to detect and can lead to severe health consequences.
Quaker’s patents relate to an invention which adds fluorescent dye to hydraulic fluid, so that if suspected injury occurs, any injection point can be detected using ultraviolet light. Quaker brought proceedings against Fuchs on the basis that they had engaged in ‘contributory infringement’ by supplying hydraulic fluid containing a fluorescent dye, knowing it would be used by their customers to perform the patented method; Quaker Chemical (Australasia) Pty Ltd v Fuchs Lubricants (Australasia) Pty Ltd (No 2)  FCA 306 (see judgement here).
A key element of Fuchs’ case, was the argument that the fluorescent dye can also be used for leak detection in tubes carrying hydraulic fluid. Fuchs claimed this was the sole purpose for their addition of the dye. Quaker disagreed, arguing that any supply of a hydraulic fluid containing fluorescent dye was an infringement.
The Judge largely agreed with Fuchs’ position because the evidence showed that the concentration of dye needed for leak detection was less than the amount needed to detect a HPFI injury and Fuchs had mostly supplied hydraulic fluid with this lower concentration.
The evidence also showed that one of Fuchs' customers had requested a higher concentration of dye and when meeting this request, Fuchs had reason to believe it would be used for HPFI detection despite their distributing the supply for the use of leak detection. This specific supply was found to be an infringement of Quaker’s patents. Quaker also claimed that the infringement in this case reflected a general intention by Fuchs to disguise infringing supplies under the guise of leak detection. However, the Judge ruled against them because of the lower dye concentrations in Fuchs’ other supplies.
This case illustrates the challenges faced by patent owners in bringing proceeding against suppliers for infringement of method claim by end users in scenarios where they are reluctant to take action against the end user
For patent applicants
While it is difficult to know the challenges faced by the patent drafter, Quaker's patent may have been more enforceable if it had been crafted to target a supplier rather than the end user.
From the perspective of a potential infringer, this case highlights the risks involved in attempting to avoid infringement of a patent that you know about. Fuchs should have advised the enquiring customer that supplying hydraulic fluid with a higher dye concerntration was not possible due to Quaker's patents or have supplied the hydraulic fluid using dye additive purchased from Quaker.
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