Envirco Corp. v. Clestra

• Decision Date: 18 April 2000
• Parties: (Fed. Cir. 2000) ENVIRCO CORPORATION, Plaintiff-Appellant, v. CLESTRA CLEANROOM, INC., Defendant-Appellee. 99-1111 DECIDED:
• Court: U.S. Court of Appeals — Federal Circuit

Page 1360

209 F.3d 1360 (Fed. Cir. 2000)

ENVIRCO CORPORATION, Plaintiff-Appellant, v. CLESTRA CLEANROOM, INC., Defendant-Appellee.

99-1111

United States Court of Appeals for the Federal Circuit

DECIDED: April 18, 2000

Appealed from: United States District Court for the Northern District of New York Senior Judge Howard G. Munson

Robert C. Faber, Ostrolenk, Faber, Gerb & Soffen, LLP, of New York, New York, argued for plaintiff-appellant. With him on the brief was Douglas A. Miro.

Francis D. Cerrito, Pennie & Edmonds, LLP, of New York, New York, argued for defendant-appellee. With him on the brief was Brian M. Poissant.

Before MAYER, Chief Judge, LOURIE, and RADER, Circuit Judges.

RADER, Circuit Judge.

Envirco Corporation (Envirco) sued Clestra Cleanroom, Inc. (Clestra) in the United States District Court for the Northern District of New York for infringement of its U.S. Patent No. 4,560,395 ('395 patent), which covers a centrifugal fan and filter assembly for clean room environments. The district court granted Clestra's motion for summary judgment of non infringement. Because the district court erred in construing the claims-in-suit and finding those claims not infringed, this court vacates and remands.

I.

Envirco owns the '395 patent. The '395 patent contains three independent apparatus claims and twenty-one dependent claims. The claims cover a compact fan and filter assembly for use in a clean room. Clean rooms are closed areas used for work that must be conducted in a dust free environment, such as production of computer chips. The claimed invention has a housing, a blower fan, a first baffle, a second baffle, and a high efficiency particulate arresting, or HEPA, filter. Figure 1 illustrates an embodiment of the claimed apparatus. The arrows in the drawing indicate the direction of airflow [Tabular or Graphical Material Omitted]

The claimed elements of the fan apparatus are arranged so that the unit - though small and compact - still efficiently creates a laminar airflow. The centrifugal fan element (37) draws air into the unit through an intake (30) on the top of the housing. Two sets of baffles then direct the air flow within the apparatus. The first baffle (58), located under the fan, directs the airflow upwardly and outwardly, toward the second baffle (67). The second baffle then directs air downwards and inwards, toward the HEPA filter (48). After passing through the HEPA filter, air flows out the underside of the enclosure.

In pre-trial proceedings the parties agreed that the second baffle is the only disputed claim element. Claim 1 of the '395 patent illustrates the asserted claims-in-suit:

1. A compact air purification apparatus for providing clean airflow to a clean air enclosure comprising a primary housing having first and second end portions and substantially closed sidewall portions, inlet and discharge openings disposed through said first and second end portions, respectively, a blower means mounted through said inlet opening so as to extend inwardly of said primary housing, said blower means having a motor drivingly connected to a centrifugal fan means, said centrifugal fan being disposed within said primary housing so as to discharge air radially outwardly with respect to said inlet opening, said centrifugal fan including a plurality of radially extending blade means, a filter means mounted within said primary housing adjacent said discharge opening so that all airflow outwardly of said primary housing through said discharge opening passes through said filter means, a first baffle means disposed adjacent said centrifugal fan means and between said centrifugal fan means and said filter means, said first baffle means having outwardly extending wall portions which extend outwardly of said centrifugal fan means toward said sidewalls of said primary housing so as to create an airflow space radially of said centrifugal fan means between said first baffle means and said sidewalls of said primary housing, second baffle means disposed radially outwardly of said centrifugal fan means and said first baffle means, said second baffle means having inner surfaces for directing the airflow from said centrifugal fan means inwardly of said primary housing and between said first baffle means and said filter means whereby air being introduced into said housing by said centrifugal fan means will be directed radially outwardly of said centrifugal fan means and guided by said first baffle means towards said second baffle means and thereafter by said second baffle means between said first baffle means and said air filter means.

'395 patent, col. 9, l. 64 - col. 10, l. 32 (emphasis added).

Clestra makes the accused infringing product, the Fantom fan. The parties agree that the Fantom has a blower fan, a first baffle, a housing, and a HEPA filter covered by the claims in the '395 patent. At issue is whether the sound dampening material of the Fantom constitutes, or is equivalent to, the second baffle means of the asserted patent claims. The district court described the Fantom's sound dampening material as "L-shaped." The Fantom actually has sound dampening material covering the interior ceiling and walls of the enclosure. Thus, only when viewed as a cross-section does the Fantom's sound dampening material appear as L-shaped.

The district court construed the term "second baffle means" of the asserted claims of the '395 patent as a means-plus-function claim element under 35 U.S.C. § 112, ¶ 6 (1994). Because the district court held that the second baffle means is a means-plus-function claim element, it looked to the specification for the corresponding structure. The district court focused its attention on one of the disclosed preferred embodiments, which included a second baffle having "continuous arcuate surfaces." '395 patent, col. 5, l. 40. Therefore, the district court limited the second baffle means to only arcuate, or curved surfaces. However, the district court overlooked other disclosed embodiments such as those in Figures 2 and 3, which both contain angular baffles.

[Tabular or Graphical Material Omitted]

[Tabular or Graphical Material Omitted]

Under this claim construction, the district court performed its infringement analysis, comparing the accused Fantom product to the claims of the '395 patent. ranting Clestra's summary judgment motion, the district court held that the Fantom does not infringe because the L-shaped material in the Fantom is not arcuate. The district court also held the claims of the '395 patent not infringed under the doctrine of equivalents. Envirco appeals.

II.

This court reviews the district court's grant of Clestra's summary judgment motionde novo. See Conroy v. Reebok Int'l, Ltd., 14 F.3d 1570, 1575, 29 USPQ2d 1373, 1377 (Fed. Cir. 1994). Clestra may prevail on summary judgment only by showing an absence of genuine issues of material fact and entitlement to judgment as a matter of law. See Fed. R. Civ. P. 56(c). In granting Clestra's motion for summary judgment, a district court must view all evidence in a light most favorable to Envirco, and draw all reasonable inferences in Envirco's favor. See SRI Int'l v. Matsushita Elec. Corp., 775 F.2d 1107, 1116, 227 USPQ 577, 581 (Fed. Cir. 1985) (en banc).

The question of infringement involves a legal analysis, interpreting the scope and meaning of the claims, and a factual analysis, applying the claims to the accused device. See Cybor Corp. v. FAS Techs, Inc., 138 F.3d 1448, 1454-56, 46 USPQ2d 1169, 1172-75 (Fed. Cir. 1998) (en banc). This appeal asks this court to review the district court's claim construction. Specifically, this court must review whether the second baffle is a means-plus-function claim element and, therefore, whether the district court properly applied a structural limitation from the written description, that of being "arcuate," to define the scope of the claims.

Section 112, ¶ 6 of title 35 of the United States Code allows patent applicants to claim an element of a combination functionally, without reciting structures for performing those...