ABB Tries to “Switch-Gears”, but is Short-Circuited by Hyundai

Published October 3rd, 2013

ABB Technology AAG, ABB Inc. and ABB AG v. Hyundai Heavy Industries Co., Ltd. 2013 FC 947 (Barnes)


On September 11, 2013, the Federal Court of Canada delivered its decision in the case of ABB, in which ABB claimed infringement by Hyundai of its Canadian Patent Nos. 2,570,772 and 2,567,781 (the ‘772 and ‘781 Patents), both of which are directed to gas-insulated switchgears (GIS).  The Court found the relevant claims of both patents invalid for obviousness and not infringed by the products manufactured and sold by Hyundai to BC Hydro.


The ‘772 Patent

The ‘772 Patent relates to an inspection window fitted in a circuit breaker housing of a GIS to assist maintenance operators in visually identifying that the circuit breaker is grounded.  Two claims were at issue in this case.  Independent claim 1 recites “an inspection window fitted in the housing such that positions of a moveable switch-contact element can be seen from the outside”.  Dependent claim 4 recites “wherein the moveable switch-contact element is provided with a coloured or topographical marking”.

In construing independent claim 1, the Court determined that the term “moveable switch-contact element” included both a sliding and a knife blade switch-contact noting that the inventors were aware of both types of switches and the language of the patent employs a generic reference to a moveable contact that does not distinguish between switch types.  The Court rejected ABB’s construction that “moveable switch-contact element” referred only to a sliding switch-contact, and did not include a knife blade switch-contact.  In regards to dependent claim 4, the Court rejected ABB’s argument that any visible feature, whatever its intended purpose, is included within the scope of the claim.

In finding independent claim 1 invalid, the Court held that the well-known use of windows as a means to view switch positions resulted in its obviousness.  ABB acknowledged that the use of windows to observe the position of knife blade switch-contacts in medium and high voltage GIS was known as of the claim date of the patent.  Given the Court’s construction of the term “moveable switch-contact element” to include a knife blade switch-contact, its obviousness finding was to be expected.

In assessing infringement, the Court found that the guide pins of Hyundai’s switchgear, which were designed to keep the moveable contact from accidently rotating, were not coloured or topographically marked, as required by dependent claim 4.  Furthermore, Hyundai’s design required cameras to assess the position of the switch and there would be no reason for BC Hydro to remove the cameras and use the windows for direct viewing.  In these circumstances, the Court found no infringement.

The ‘781 Patent

The ‘781 Patent relates to dimensioning a circuit breaker compartment such that circuit breakers, isolators and ground conductors are arranged within the compartment in order to comply with North American requirements.

In construing the relevant claims, the Court disagreed with ABB that placing the ground conductors in the same compartment was not an essential feature.

In holding the relevant claims invalid, the Court found them to be obvious in view of several references disclosing placing all three elements in a single compartment in a GIS which used compressed gases despite the prior art not disclosing the sulfur hexafluoride (SF6) gas used in the patent.  ABB argued that there were numerous structural issues associated with having all elements in a single compartment in SF6 GIS, but the Court found that these issues were not discussed in the patent and noted several inconsistencies between ABB’s witnesses in regards to the degree of structural issues.  ABB also acknowledged that the features of the dependent claims were known in the prior art.

In assessing infringement of the relevant claims, the Court found that Hyundai’s switchgear did not include the essential element of ground conductors within the compartment and as such, determined that no infringement had occurred.

Practice Point

This was a fairly straightforward validity and infringement case that turned on the specific facts contained therein.  There were several cautionary remarks made by the Court that should be heeded by all patentees.  Firstly, had a dependent claim to sliding switch-contacts been included in the ‘772 Patent, invalidity of such a claim may not have been found.  Secondly, since the inclusion of the ground conductors in the circuit breaker compartment of the ‘781 Patent was asserted by ABB to be optional, making this the subject matter of a dependent claim, rather than including it in the independent claim, may have saved the patent and resulted in a finding of infringement.  Lastly, the Court clearly favoured Hyundai’s witnesses, noting frequent contradictions within the testimony of ABB’s witnesses as well as between ABB’s witnesses.  Patent litigants are warned to carefully choose witnesses as their testimony may be the difference between a finding of invalidity and non-infringement and one of validity and infringement.

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