The opinion of the court was delivered by: Jeanne E. Scott, U.S. District Judge
This matter comes before the Court on the following Motions for Partial Summary Judgment:
1. Plaintiff GSI Group, Inc.'s (GSI) Motion for Partial Summary Judgment for Infringement of GSI's Burner Cone Patent by Sukup's Frustoconical Burner Cone Heater (d/e 431) (Motion 431);
2. Defendant Sukup Manufacturing Company's (Sukup) Motion for Summary Judgment of Invalidity of U.S. Patent 5,400,525 (d/e 449) (Motion 449); and
3. Defendant Sukup's Motion for Summary Judgment of Non-Infringement of U.S. Patent No. 5,400,525 (d/e 450) (Motion 450).
For the reasons set forth below, the Court allows Motion 450, allows Motion 431 in part, but denies Motions 449. U.S. Patent 5,400,525 (525 Patent), covers a cone ("Burner Cone" or "Flame Cone") that is inserted in the burner of a heater to improve efficiency. Sukup Unsealed Exhibits (d/e 461), Exhibit 23, 525 Patent.*fn1 Sukup has failed to show that it is entitled to summary judgment on the invalidity of the 525 Patent; thus, the validity of the 525 Patent remains an issue for trial.*fn2 If the 525 Patent is valid, Sukup has established that Sukup's current heater design does not infringe on the Patent. GSI has established that Sukup previously sold a heater that literally infringed on the 525 Patent if the 525 Patent is valid. GSI is not entitled to a partial judgment of infringement because the validity of the 525 Patent has not been resolved.
The Patent and Trademark Office (PTO) issued the 525 Patent on March 28, 1995. The claimed invention covered by the 525 Patent is a heater for a grain bin. The heater consists of a blower that blows air through a cylindrical housing. A burner located in the housing heats the air that passes through the housing. The heated air is then directed under the floor of a grain bin. The heated air rises through perforations in the floor and dries the grain in the bin. According to the 525 Patent, the prior art included a flame diverter (Diverter) placed around the burner. The Diverter consisted of perforated slats formed into a conical shape with openings between the slats. The smaller end of the Diverter ringed the burner, and then the conical shape opened away from the burner to the larger end of the Diverter. The Diverter generally directed the flame in one direction. The perforations in the Diverter's slats and the spaces between the slats allowed air to flow through the Diverter in order to be heated. Attached as Appendix A is a depiction of prior art from the 525 Patent.
The 525 Patent explained that an area of low pressure (identified as "L.P." in Appendix A) developed in the center of the Diverter. The low pressure area resulted in inefficient and incomplete consumption of fuel by the burner. The claimed invention of the 525 Patent was the insertion of the Flame Cone. The smaller end of the Flame Cone was placed next to the burner inside of the Diverter. The slopes of the conical sides of the Flame Cone and the Diverter were generally the same, leaving a gap between the Flame Cone and the Diverter. The Flame Cone eliminated the low pressure area that existed in the prior art and diverted the flames into the gap between the Flame Cone and the Diverter. According to the 525 Patent, this diversion of the flames resulted in complete consumption of the fuel, and so, a more efficient burner. Attached as Appendix B is a diagram from the 525 Patent of the invention with the Flame Cone.
The 525 Patent had three claims. Claim 1 stated that the burner had a Diverter, "comprising a cone-shaped structure diverging outwardly from said burner . . ., said diverter having a plurality of spaced openings therein for permitting air moved by said blower to pass therethrough. . . ." 525 Patent, at 7. Claim 1 then stated that the improvement on the prior art consisted of: a flame cone having an apex and an outer base spaced axially from said apex with the slope of said flame cone being generally similar to the slope of said diverter, said apex of said flame cone being positioned proximate said burner on the inside of said diverter so that there is a gap between the inside face of said diverter and the outer surface of said flame cone so as to provide a path for the burning fuel to travel from said burner outwardly . . . thereby to result in more complete combustion of said fuel.
Id. Claim 2 stated that the gap between the Diverter and the Flame Cone, "ranges between about 1 inch and about 6 inches." Id.
Claim 3 stated, in part, that the invention resulted in, "at least partially confining said burning fuel within said housing into a gap formed between the inside face of said diverter and a flame cone . . . thereby to result in said flame burning with a blue color thus indicating that said fuel is being substantially completely combusted." Id.
Twenty years earlier the PTO issued U.S. Patent No. 3,881,863 (863 Patent). Sukup Unsealed Exhibits, Exhibit 19, 863 Patent. The 863 Patent covered a dual fuel burner designed to be installed as a heater in an air ventilation system. The burner was called a dual fuel burner because it was designed to use either liquid or gaseous fuel. The covered invention was specifically designed to burn fuel completely so that the burner would not produce toxic gases such as carbon monoxide. As a result, the heated air passing directly through the burner would be safe for humans to breathe. The claimed invention was also designed to work effectively with varying rates of fuel consumption in order to allow variable heating of the air within the ventilation system.
Attached as Appendix C is a copy of the diagram of the covered invention from the 863 Patent. The 863 Patent had a conically shaped perforated Flame Basket, rather than a Diverter, which extended out from the burner.*fn3 The 863 Patent also had a cone, called a Diffuser, placed at the large end of the Flame Basket with its point facing into the Flame Basket toward the burner located at the small end of the Flame Basket. At low levels of fuel consumption, the flame would be contained in the center of the Flame Basket underneath the Diffuser. At high levels of fuel consumption, the flame would hit the Diffuser and be forced out toward the walls of the Flame Basket as the flame exited the heater. The Diffuser (in combination with a metal ring at the large end of the Flame Basket and the heated air that flows through the final ring of perforations located at the large end of the Flame Basket) would force the flame that exited the heater to curve inwardly. Attached as Appendix D is a diagram showing the flame from either low or high fuel consumption. The flame at low fuel consumption is represented by small flames located at the perforations in the Flame Basket, marked as "14a" on Appendix D. The flame at high fuel consumption is shown by the depiction of flames extending out of the end of the heater, marked as "14" on Appendix D.
In 1999, Sukup started selling a grain bin heater. Sukup studied the GSI heater design, including the claim invention covered by the 525 Patent. Sukup's design of its heater was the same as the GSI design covered by the 525 Patent. Motion 431, Exhibit 8, Expert Witness Report of Randall Sheley, at 8-16. Sukup sold these heaters until March 2005.
Thereafter, Sukup redesigned its heater. Sukup removed the Flame Cone from within the Diverter. In its place, Sukup inserted 3 round metal plates separated from each other by metal spacers. The plates were parallel with each other. Each plate was slightly larger than the one beneath it. All three plates were centered on the same axis, forming a tiered, or "wedding cake" design (hereinafter Wedding Cake Insert). Attached as Appendix E is a depiction of the Wedding Cake Insert. Sukup Sealed Exhibits (d/e 460), Exhibit 122, Wedding Cake Design Drawing. The Wedding Cake Insert was inserted in the center of the Diverter next to the burner, in lieu of the Flame Cone. Some space existed between the Diverter and the edge of each plate in the Wedding Cake Insert. The diameters of the plates of the Wedding Cake Inserts were close to the profile of the slope of the slats of the ...