Schulman, Lee Ann Stevenson and Vickie Reznik, of New York, NY. The district court entered judgment against Sundstrand. In the claimed invention, “[a]mbient air ․ is drawn through a set of adjustable inlet guide vanes.” ′893 patent, col. The value of the set point is selected “as a function of the position of said inlet guide vanes.” Id., col.
Of counsel were Christian Douglas Wright and Josy W.
Ingersoll, Young Conaway Stargatt & Taylor, LLP, of Wilmington, DE. Ziegler, Cleary, Gottlieb, Steen & Hamilton, of New York, NY, for defendant-cross appellant.
The jury found that the patents in suit were valid and, although not literally infringed, infringed under the doctrine of equivalents. To reach this end, Honeywell's invention establishes a “set point” that represents the minimum flow at which surge can safely be avoided. The set point is compared to a “flow-related parameter” that represents airflow out of the compressor as determined by a sensor. IIThe ′893 and ′194 patents resulted from a common application filed February 19, 1981.
We affirm the district court's judgment rejecting Sundstrand's counterclaims of invalidity.
Sundstrand filed a motion for partial summary judgment to limit damages to those incurred after February 3, 1999, the date it received actual notice of Honeywell's infringement allegations, because Honeywell did not mark its product under 35 U.
A control system for assuring a substantially constant minimum flow rate through a duct receiving air discharged from a compressor or the like having adjustable inlet guide vanes, the duct having a supply outlet connected to pneumatically-operated apparatus having a variable supply air demand, the duct further having an exhaust outlet, said control system comprising:(a) a flow regulating device adapted to be positioned in the exhaust outlet and operable to selectively vary air flow outwardly therethrough;(b) a sensing device having a sensing portion adapted to be positioned in the duct to sense therein a predetermined parameter related to the air flow rate through the duct, said sensing device further having an output portion;(c) an adjustable set point comparator having an input portion coupled to said output portion of said sensing device, and an outlet adapted to generate an error signal;(d) a proportional controller having an inlet coupled to said output of said comparator and further having an outlet;(e) an integral controller having an inlet coupled to said outlet of said comparator and further having an outlet;(f) a summer having a first inlet coupled to said outlet of said proportional controller, a second inlet coupled to said outlet of said integral controller, and an outlet coupled to said flow regulating device; and(g) a guide vane position sensor and a function generator coupled in series between the inlet guide vanes and said input portion of said comparator. The APS 3200 solves this problem by blocking the control signal during high-flow conditions. The district court also held that Honeywell could not recover damages for sales entered into before to February 3, 1999, even if delivery occurred thereafter.
The system uses in part IGV position to determine whether the APU is experiencing high flow or low flow, and consequently whether to block the control signal. Honeywell conceded that it did not mark its product with the ′893 patent, but argued that the ′194 method claim patent did not permit or require marking. Hamilton Sundstrand Corp., No 99-309, 2001 WL 66345, at *3-4 (D. The broader original independent claims were cancelled. To do this it is necessary to determine when and how far to open the surge bleed valve in order to maintain a level of flow sufficient to avoid surge. If the system determines that airflow out of the main air duct is too low, the surge bleed valve will be opened to prevent the build up of excess pressure leading to surge. 4,380,893 (the “′893 patent”) and claim 4 of Patent No. All of the asserted independent claims were originally dependent claims that were rewritten into their present independent form during prosecution. The Honeywell APU is designed to be more efficient by avoiding excess air bleeding in its control of surge. Thus a comparison is made between the actual flow conditions (represented by the flow-related parameter) and the desired flow conditions (represented by the set point). A valve is used to control the amount of air exiting the compressor through the main air duct, which supplies compressed air to the aircraft's systems. During flight, the amount of compressed air required for these purposes fluctuates substantially.