View source for Homework: Honeywell v. Sundstrand brief; On behalf of Sundstrand

== Brief on Behalf of Hamilton Sundstrand Corporation ==

The appeal by Honeywell International, Inc. (henceforth referred to as “Honeywell”) should be rejected. Honeywell claims that Sundstrand’s APS 3200 APU device, which utilizes the DELPQP parameter and IGV (inlet guide vane) position to control airflow, infringes on Honeywell’s APU device that does the same thing, only without the same use of the IGVs. However, based on the prosecution history estoppel, Honeywell has no grounds to assert the doctrine of equivalents in proving its case of infringement against Sundstrand. 

There are only two ways in which Honeywell could use the doctrine against the Respondent and overcome the estoppel preventing cause for infringement. The first is they could prove that the “alleged equivalent,” or the measuring of position of the IGVs to determine proper air flow, was unforeseeable at the time that Honeywell spelled out their claims in the patent. If the equivalent was unforeseeable, it would be understandable that the patent owner did not include that equivalent in the claim. If, however, the equivalent was foreseeable at the time of the patent’s filing, and the owner failed to define it as part of the scope of the patent, doctrine of equivalents would not apply, since the owner could be presumed to surrender that knowledge as not pertinent to the invention. 

Honeywell fails to meet this first requirement. The District Court found, after extensive testimony, that at the time of filing, Honeywell could have used IGV positioning to determine airflow. Honeywell surrendered any right to the use of the IGV positioning knowledge when it failed to include it in the claims, though its application was well known at the time of invention. There is no reason, Sundstrand argues, for this finding to be overturned by this Court. To do so would run counter to the purpose of patent claims, which is to define the patent’s scope, and leave knowledge not addressed free for the public’s use. 

The second way for Honeywell to overcome the estoppel would be to prove that, when the original patent claims were modified in order to make the patent patentable, the amendment made to narrow the claim’s scope had only a tangential relation to the alleged equivalent. The record on hand, however, shows that the original claims included the IGV “limitation,” showing that the relation to the equivalent is very much direct. The narrowing amendment, in addition to the foreseeability of the IGVs, proves that Honeywell should remain barred via prosecution history estoppel from using the doctrine of equivalents against Sundstrand.