Kwik Products, Inc. v. National Express, Inc.

NOTE: Pursuant to Fed. Cir. R. 47.6, this disposition is not
citable as precedent. It is a public record.
United States Court of Appeals for the Federal Circuit
05-1319
KWIK PRODUCTS, INC.,
Plaintiff/Counterclaim Defendant-
Appellant,
and
FERNANDO R. IACONA and IGNAZIO M. IACONA,
Counterclaim Defendants-Appellees,
v.
NATIONAL EXPRESS, INC., CMD PRODUCTS, GEORGE E. ALLISS,
ALEX J. PHINN, JR., GRIFF AND ASSOCIATES, L.P.,
and TORVIAN, INC.,
Defendants/Counterclaimants-
Appellees.
_____________________
DECIDED: April 26, 2006
_____________________
Before MICHEL, Chief Judge, MAYER and LOURIE, Circuit Judges.
LOURIE, Circuit Judge.
Kwik Products, Inc. (“Kwik”) appeals from the judgment of the United States
District Court for the Southern District of New York of noninfringement of U.S. Patent
5,896,666 in favor of National Express, Inc., CMD Products, George E. Alliss, Alex J.
Phinn, Jr. and Griff and Associates, L.P., and Torvian, Inc (collectively “Torvian”). Kwik
Prod., Inc. v. Nat’l Express, Inc., No. 03-9291 (S.D.N.Y. March 29, 2006) (“Final
Judgment”). Because the district court correctly construed the claim limitation “clamping
means” and did not clearly err in finding no literal infringement of claim 1 and no
infringement of claim 15 under the doctrine of equivalents, we affirm.
BACKGROUND
Vegetation trimmers are outdoor power tools used to cut grass, weeds, and other
vegetation, and feature a replaceable head that spins a blade or string at speeds up to
10,000 rpm. Kwik Prod., Inc. v. Nat’l Express, Inc., 356 F. Supp. 2d 303, 305 (S.D.N.Y.
2005) (“Opinion”). The ’666 patent, entitled “Head for String Trimmer,” assigned to
Kwik, is directed to a vegetation trimmer head that can be easily reloaded. Independent
claim 1 discloses a combination of a cutting head and string for cutting and trimming
vegetation comprising at least one generally straight length of string, a cutting head, and
a clamping means for fixing the string to the head. ’666 patent, col. 6, ll. 37-55. Claim
2, which depends from claim 1, adds the limitation that the clamping means include a
pivotally mounted clamping member and a pressing wall aligned to cooperatively clamp
the string. Id., col. 6, ll. 56-59. Independent claim 15, which also discloses a cutting
head for a string trimmer, requires a clamping member that is pivotally mounted and
urged by a spring in a clockwise direction around a pivot post against an opposing wall.
Id., col. 8, ll. 18-44.
As illustrated in Figure 3, the clamping member (36), which is a cam in this
embodiment, rotates on the pivoting post (38), pressing the string (14) against the
pressing wall (32). The center of gravity of the cam is denoted by the letters “CG” and a
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spring (40) biases the cam so that it will rotate in a certain direction. The spring has one
end secured to the cam and the other end secured to a bracket in the side wall.
Kwik began manufacturing the commercial embodiment of the ’666 patent in
1998. Opinion, 356 F. Supp. 2d. at 308. In 2000, George Allis developed a competing
vegetation trimmer head. Id. at 309. Allis’s device used a spring-biased, slideable
clamping member with a compression spring to hold straight lengths of trimmer string in
place. Id. On June 24, 2003, the U.S. Patent and Trademark Office (“PTO”) issued
U.S. Patent 6,581,292, entitled “Vegetation Trimmer Apparatus,” covering Allis’s
invention. Id. at 309-10. Torvian later marketed its commercial embodiment of that
invention as the “Grass Gator Load n’ Cut.” Id. at 310.
On November 21, 2003, Kwik filed suit against Torvian in the United States
District Court for the Southern District of New York, alleging infringement of claims 1, 2,
and 15 of the ’666 patent. Kwik filed an amended complaint on April 28, 2004. In its
May 28, 2004, answer to the amended complaint, Torvian asserted a single
counterclaim for a declaratory judgment of invalidity and unenforceability of claims 1-10
and 15-19 of the ’666 patent. The case was tried to the district court without a jury in
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October 2004. It is undisputed that Torvian did not put in evidence on the issue of
inequitable conduct during trial.
At the conclusion of trial, the district court, in an excellent and thorough opinion,
held that Torvian did not infringe the ’666 patent, either literally or under the doctrine of
equivalents. The court first held that 35 U.S.C. § 112 ¶ 6 applied to claim 1 so that
“clamping means” was limited to “a spring element working with a pivotally mounted
clamping member with a strategically placed center of gravity.” Id. at 318-19. Second,
relying on the specification, the court construed “spring” in claim 15 as referring to an
“extension or torsion spring.” Id. at 319. The court then determined that the Allis device
did not literally infringe the asserted claims because it did not use a pivotally mounted
clamping member or rely on a strategically placed center of gravity. Id. The court also
found that the Allis device did not infringe the asserted claims under the doctrine of
equivalents because it did not meet four limitations of the ’666 patent: a pivotally-
mounted clamping member, rotational movement of the clamping device, a clamping
member in which the location of the center of gravity was significant, and a spring
attached to the cam and the other to a side wall. Id. at 320. The court observed that
the Allis device used a slideably-mounted clamping member, a linear sliding motion, a
clamping force that was not influenced by the center of gravity, and an unattached
compression spring. Id.As to invalidity, the court held that claims 1-10 and 15-19 were not anticipated or
rendered obvious by prior art. Id. at 322-23. The court found that none of the prior art
references disclosed “a spring for urging a clamping member in the direction of a
pressing wall or a pivotally mounted clamping member urged by a torsion spring and
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working together with centrifugal force to hold a straight length of spring in place.” Id. at
322. The court also concluded that it would not have been obvious to one of ordinary
skill in the art to modify one or more of the prior art references to use “a spring biased,
cam shaped, pivotally mounted clamping member to hold a fixed length of string in
place in a trimmer head rotating at 10,000 rpm.” Id. at 323. The court pointed out that
“though some of the prior art references had existed for many years, there still was a
long-felt need for a convenient and easy-to-load trimmer head as late as the 1990s.” Id.On February 24, 2005, the court entered a judgment dismissing Kwik’s claims for
patent infringement and dismissing Torvian’s “counterclaim for invalidity.” Judgment,
slip op. at 1. Kwik filed a Notice of Appeal on March 18, 2005, and Torvian filed a
Notice of Appeal on March 25, 2005. We determined that the district court had not
adjudicated Torvian’s unenforceability counterclaim, which rendered the district court’s
judgment nonfinal for purposes of an appeal. However, we restated the principle that “a
premature notice of appeal ripens upon subsequent action of the district court.” Kwik
Prod., Inc. v. Nat’l Express, Inc., No. 05-1319, -1343, slip op. at 4 (Fed. Cir. March 13,
2006) (quoting Pause Tech. LLC v. TiVo Inc., 401 F.3d 1290, 1295 (Fed. Cir. 2005)).
Hence, we permitted the parties to seek remedial action in the district court and move
this court to reinstate the appeal from a final judgment.
Kwik returned to the district court requesting dismissal of Torvian’s
unenforceability counterclaim. The court agreed to dismiss the counterclaim, and Kwik
filed an amended notice of appeal to reinstate its appeal of the court’s judgment of
noninfringement. However, Torvian did not file an amended notice of appeal to
reinstate its cross-appeal of the court’s judgment of no invalidity. Therefore, we
05-1319 5
reinstated Kwik’s appeal as to noninfringement, but not Torvian’s cross-appeal as to
invalidity.
We now turn to the merits of Kwik’s appeal from the judgment of
noninfringement, as that judgment is final, and we have jurisdiction pursuant to 28
U.S.C. § 1295(a)(1).
DISCUSSION
Claim construction is an issue of law, Markman v. Westview Instruments, Inc., 52
F.3d 967, 970-71 (Fed. Cir. 1995) (en banc), that we review de novo, Cybor Corp. v.
FAS Techs., Inc., 138 F.3d 1448, 1456 (Fed. Cir. 1998) (en banc). The district court's
determination of infringement, in contrast, is a question of fact that we review for clear
error. Centricut, LLC v. Esab Group, Inc., 390 F.3d 1361, 1367 (Fed. Cir. 2004). “A
finding is ‘clearly erroneous’ when although there is evidence to support it, the reviewing
court on the entire evidence is left with the definite and firm conviction that a mistake
has been committed.” United States v. U.S. Gypsum Co., 333 U.S. 364, 395 (1948).
On appeal, Kwik argues that the district court erred in holding that § 112, ¶ 6
applied to the term “clamping means” in claim 1 of the ’666 patent. According to Kwik,
because a clamp identifies a device that has a reasonably well understood meaning in
the art, “clamping means” is not a means-plus-function limitation. Kwik contends that
under the proper construction of “clamping means,” there is no limitation that it comprise
a pivotally mounted clamping member having a particularly located center of gravity, as
supported by the doctrine of claim differentiation. Kwik also argues that the court erred
in construing the term “spring” in claim 15 of the patent to be limited to extension and
torsion springs. Kwik asserts that the ordinary and customary meaning of the term
05-1319 6
“spring” is not limited to the specific types of springs disclosed in the specification, and
thus includes compression springs. Based on its construction of “clamping means” and
“spring,” Kwik contends that claim 1 is literally infringed and claim 15 is infringed under
the doctrine of equivalents. Kwik points out that the slideably mounted clamping
member of the accused device is equivalent to the pivotally mounted clamping member
recited in claim 15 of the patent because it performs the same function (to clamp the
string), in the same way (by being urged toward the opposed way under a spring force),
to achieve the same result (fixing the string in the trimmer head).
Torvian responds that the district court correctly applied § 112, ¶ 6 to the term
“clamping means” because the claim is written in classic means-plus-function format,
and Kwik failed to rebut the presumption that § 112, ¶ 6 applies. According to Torvian,
the court correctly limited “clamping means” to the structures identified in the
specification: a pivotally-mounted clamping member, either biased by a torsion or
extension spring against an opposing wall or completely unbiased (in which event the
force is applied manually), and a strategically-placed center of gravity, which increases
the clamping force while the trimmer head is spinning. Torvian also contends that the
court correctly relied on the specification to construe the term “spring” as a torsion or
extension spring, but not a compression spring because the patent’s reference to a
“generic” spring is ambiguous. Finally, Torvian argues that the accused device does not
infringe claims 1 and 15 of the patent, either literally or under the doctrine of
equivalents, because it contains a slideably-mounted clamping member, biased by a
compression spring, whose clamping force is not influenced by the location of its center
of gravity. Torvian points out that the accused device not only contains different
05-1319 7
structures from those disclosed in the ’666 patent, but also functions in a different way,
such that the force applied to hold the cutting string in place is applied rectilinearly
rather than through circular or rotational application of force.
We agree with Torvian that the district court correctly construed the term
“clamping means” in claim 1 as a means-plus-function limitation. A claim using the
means-plus-function format will cover only the corresponding structure disclosed in the
written description, as well as that structure's equivalents. 35 U.S.C. § 112, ¶ 6;
Personalized Media Commc’n, LLC v. Int'l Trade Comm'n, 161 F.3d 696, 703 (Fed. Cir.
1998). A claim limitation that actually uses the word “means” will invoke a rebuttable
presumption that § 112, ¶ 6 applies. Id. at 703-04. In this case, claim 1 phrases the
“clamping means” limitation in means-plus-function language, thereby triggering the
presumption. Because Kwik has not rebutted that presumption, the claim must “be
construed to cover corresponding structure, material, or acts described in the
specification and equivalents thereof.” 35 U.S.C. § 112, ¶ 6.
Here, the specification of the ’666 patent discloses a “clamping member [that] is
pivotally mounted adjacent each aperture, opposite the corresponding pressing wall so
that its center of gravity is disposed between the pivotal mounting and the
corresponding pressing wall.” ’666 patent, col. 3, ll. 4-7. Further, as the district court
correctly observed, the specification refers to “two degrees of clamping force,” one that
is generated by springs that hold the string in place when the cutting head is not in use
and a second that is generated when the cutting head rotates and creates a centrifugal
force “that acts on the centers of gravity of the clamping members and enhances the
gripping force thereof.” Id., col. 3, ll. 7-17. Therefore, the court did not err in construing
05-1319 8
the means-plus-function limitation “clamping means” to mean “a spring element working
with a pivotally mounted clamping member with a strategically placed center of gravity.”
Opinion, 356 F. Supp. 2d at 318.
We reject Kwik’s argument that the well understood meaning of “clamp” rebutted
the presumption that § 112, ¶ 6 applies to the limitation “clamping means.” Even
assuming that the term “clamp” had a reasonably well understood meaning in the art, a
clamp is not the same as a clamping means. Equally unpersuasive is Kwik’s argument
that claim differentiation requires a different interpretation of “clamping means.” As we
stated in Laitram Corp. v. Rexnord, Inc., 939 F.2d 1533 (Fed. Cir. 1991), “[a] means
plus function [element] is not made open-ended by the presence of another claim
specifically claiming the disclosed structure which underlies the means clause or an
equivalent of that structure.” Id. at 1538. We further stated that “one cannot escape
[the] mandate [of § 112, ¶ 6] by merely adding a claim or claims specifically reciting
such structure or structures.” Id. Because we conclude that § 112, ¶ 6 applies to the
limitation “clamping means” in claim 1, we do not address Kwik’s remaining arguments
as to the construction of that term.
Having affirmed the district court’s claim construction of the term “clamping
means,” we also affirm its judgment of no literal infringement of claim 1. Kwik’s
argument that there was literal infringement of claim 1 depends entirely upon a finding
that the term “clamping means” is not a means-plus-function limitation. Because § 112,
¶ 6 does apply to that term, the court made no clear error in determining that the
accused device did not literally infringe claim 1 of the ’666 patent.
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We also affirm the district court’s judgment of no infringement of claim 15 under
the doctrine of equivalents. As an initial matter, we note that we do not reach the issue
of the correct interpretation of the term “spring” in claim 15 because the district court’s
determination of noninfringement under the doctrine of equivalents does not rely solely
upon its construction of that term. Even under Kwik’s proposed construction of “spring”
as including compression springs, the court made no clear error in finding that the
accused device did not perform substantially the same function in substantially the
same way to achieve substantially the same result as the invention claimed in claim 15
of the ’666 patent.
Specifically, the court identified four ways in which the accused device functions
differently from the invention claimed in claim 15: the patent requires a pivotally-
mounted clamping member, whereas the accused device uses a slideably mounted
clamping member; the patent requires a rotational movement of the clamping member,
whereas the accused device uses a linear, sliding motion; the location of the center of
gravity of the clamping member is significant in the patented invention, whereas the
center of gravity does not influence the clamping force in the accused device; and the
patent describes two types of springs – a torsion and extension spring – that are
attached at one end to the cam and at the other end to a side wall, whereas the
accused device uses a compression spring that is not attached to any structure.
Opinion, 356 F. Supp. 2d at 320. The first three findings are not clearly erroneous, and
irrespective of the construction of the word “spring,” each of those findings provides an
independent basis for affirming the court’s finding that the accused device did not
infringe claim 15 under the doctrine of equivalents.
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CONCLUSION
We affirm the district court’s construction of the limitation “clamping means,” and
its finding of noninfringement in favor of Torvian.
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