infringement action against a competing marine float, arguing
that the competing product infringed claim 10 under the doctrine
of equivalents. The Federal Circuit rejected this argument,
applying prosecution history estoppel to the passage limitation
in claim 10 because of amendments made to claim 1 during
prosecution. Id. at 260 ("The fact that the `passage' clause
of patent claim 10 was not itself amended during prosecution
does not mean that it can be extended by the doctrine of
equivalents to cover the precise subject matter that was
relinquished in order to obtain allowance of claim 1."). The
court encouraged consideration of the prosecution history of all
claims when assessing the "fair scope" of the claim in suit.
As in Builders Concrete, HPMC was identified in at least one
claim from the start. The limitation was added to other claims
during prosecution. In both cases, the amendment was made at the
Examiner's request.*fn5 This bars infringement of claim 1 by
Long-standing rules of claim construction also estop plaintiff
from invoking the doctrine of equivalents. HPMC is used
repeatedly throughout the patent and should be interpreted
consistently across claims. The Federal Circuit has long
recognized the need to interpret words or phrases consistently
both within and across a patent's claims. See, e.g.,
Phonometrics, Inc. v. Northern Telecom Inc., 133 F.3d 1459,
1465 (Fed.Cir. 1998) ("A word or phrase used consistently
throughout a claim should be interpreted consistently");
CVI/Beta Ventures, Inc. v. Tura LP, 112 F.3d 1146, 1159 (Fed.Cir.
1997) ("[W]e are obliged to construe the term `elasticity'
consistently throughout the claims"); Southwall Techs. v.
Cardinal IG Co., 54 F.3d 1570, 1584 (Fed.Cir. 1995) ("[O]nce an
argument is made regarding a claim term so as to create an
estoppel, the estoppel will apply to that term in other
The meaning of HPMC in claim 1 cannot be determined in
isolation. To the contrary, construction of the term in disputed
claim 1 requires reference to both the specification and the
other claims. The court's narrow construction of HPMC in claims
14, 15, 18 and 19 extends to claim 1. Prosecution history
estoppel bars infringement by equivalents throughout the '798
patent. See Texas Instruments Inc. v. United States Int'l Trade
Comm'n, 988 F.2d 1165, 1175 (Fed.Cir. 1993) ("The prosecution
history estoppel we hold proven on claim 12 is equally
applicable to claims 14 and 17").
For the reasons above, plaintiff may not assert infringement
by equivalents of claim 1.
For the foregoing reasons, the court hereby GRANTS defendant's
motion for summary judgment and DENIES plaintiffs motion for
sua sponte summary judgment.
IT IS SO ORDERED.