Issue 215 | June 15, 2004
Dr. Harry Gaus v. Conair Corp.

In Dr. Harry Gaus v. Conair Corp., Nos. 03-1295, -1310, (Fed. Cir. April 1, 2004), the federal circuit reversed a jury’s finding of infringement under the doctrine of equivalents, willfulness, and a damages award including $28.5 million in compensatory damages and an enhancement of $8,550,000 for willfulness.

Dr. Gaus’ ’047 patent is directed to a safety mechanism that prevents fatal shocks to users of electrical appliances (such as hairdryers), and describes protective circuitry that includes “a pair of spaced-apart electrically exposed conductive probe networks.” The protective circuitry in the accused Conair hairdryer does not include a pair of probe networks separate from the voltage-carrying operating unit of the appliance. Instead, the Conair device had a single sense wire that branches throughout the housing near the voltage-carrying operating elements of the device. The district court denied Conair’s summary judgment motion for noninfringement, disagreeing with its argument that its device did not meet the “pair of . . . probe networks” limitation. A jury found infringement under the doctrine of equivalents.

On appeal, the federal circuit concluded that the implication of both the claim language and the specification was that the pair of probe networks was a distinct component, separate from the electrical operating unit of the claimed invention. According to the court, the Conair device operates differently because the protective circuit is not triggered until water reaches a voltage-carrying component and creates an electrical connection between that component and the sense wire, at which point current triggers the protective circuit that shuts off the power to the device. Because Conair’s hairdryer did not have a pair of probe networks separate from the electrical operating unit (as required by claim 12 of the ’047 patent), Conair’s device did not literally infringe the ‘047 patent.

Reversing the finding of infringement under the doctrine of equivalents, the court held that the ’047 patent excluded structure of Conair’s hairdryers as being outside the patent’s scope. The court relied on various portions of the ‘047 patent specification criticizing prior art in which the protective device relied on the fluid coming in contact with the voltage-carrying portions of the system, and stating that the claimed invention avoided the resulting problem (an electric shock to the user). The court stated:

Having disavowed coverage of devices in which the two components are not separate and in which the protective cut-off mechanism is not triggered until the water reaches the electrical operating system, the patentee cannot reclaim that surrendered claim coverage by invoking the doctrine of equivalents.

To view the full decision visit http://www.aplf.org/mailer/Issue215.doc

To discuss this topic further, please feel free to contact the author Michael R. Dzwonczyk, (mdzwonczyk@sughrue.com), at Sughrue Mion, PLLC in Washington DC., USA.

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