Davies Innovations Inc v. Sig Sauer Inc

Filing 70

///ORDER granting in part and denying in part 49 Motion for Summary Judgment. So Ordered by Judge Landya B. McCafferty.(gla)

UNITED STATES DISTRICT COURT
FOR THE DISTRICT OF NEW HAMPSHIRE
Davies Innovations, Inc.
v.

Civil No. 16-cv-352-LM
Opinion No. 2017 DNH 028

SIG Sauer, Inc. and
Sturm, Ruger & Company, Inc.
O R D E R
Plaintiff Davies Innovations, Inc. brought separate patent
infringement lawsuits against SIG Sauer, Inc. (“SIG Sauer”) and
Sturm, Ruger & Company, Inc. (“Ruger”) in the United States
District Court for the Southern District of Texas, Galveston
Division.

See Davies Innovations, Inc. v. SIG Sauer, Inc., No.

3:15-cv-00281 (S.D. Tex. filed Oct. 9, 2015); Davies
Innovations, Inc. v. Sturm, Ruger & Company, Inc., No. 3:15-cv00282 (S.D. Tex. filed Oct. 9, 2015).

In both actions,

plaintiff alleged infringement of the same patent, United States
Patent No. 7,827,722 (the “‘722 Patent”), which discloses a
rifle.
Defendants separately moved in their respective actions to
transfer their cases to this court, and both motions were
granted.

Once transferred, the court consolidated the two cases

for pre-trial purposes.
Ruger moves for summary judgment of noninfringement (doc.
no. 49), asserting that the ‘722 patent requires that the

rifle’s handguard have an “open” forward end “to permit access”
to certain components of the rifle’s operating system.

Ruger

asserts that its rifles that allegedly infringe the ‘722 patent
(the “accused rifles”) lack this feature.

Plaintiff objects,

arguing that summary judgment is inappropriate.1
Background
The ‘722 patent issued on November 9, 2010.

The patent was

issued to Robert Davies, who was the President of Advance Device
Design and RF Power Devices, Inc.

After Mr. Davies passed away

in October 2012, the ‘722 patent was assigned, first to Mr.
Davies’ friend, David Stanowski, and subsequently, on October 7,
2015, to Davies Innovations, Inc. (“Davies”), the plaintiff in
this case.

Two days after the assignment, Davies filed the

instant lawsuits against SIG Sauer and Ruger, alleging that both
defendants infringe the ‘722 patent by offering to sell and
selling rifles covered by the patent’s claims.

See 35 U.S.C. §

271(a).
The ‘722 patent generally discloses a gas-piston driven
rifle having an upper receiver, a bolt carrier, a barrel, a

Ruger moved for summary judgment before the court approved
the parties’ proposed discovery plan. At the scheduling
conference, the parties agreed that Ruger’s motion would, if
granted, entirely dispose of the claims against Ruger. The
court agreed to entertain Ruger’s motion at this early stage of
the litigation and to issue an expedited ruling thereon.
1

2

handguard, and a gas-piston operating system that is at least
partially removable through a plug in the front of a barrel
coupling that serves to redirect gases from the discharge of the
weapon to a piston assembly.

The gases force the piston

assembly rearward, causing a force to be exerted on the bolt
carrier, which forces the bolt carrier rearward to eject the
spent cartridge casing.
The dispute in this summary judgment motion centers on the
handguard.

Every claim of the ‘722 patent requires that the

rifle have a handguard with an open forward end to permit access
to certain components of the rifle’s operating system.2
Specifically, Claim 1 of the ‘722 patent provides:
1. A rifle having an upper receiver carrying a bolt
carrier and a barrel attached to the upper receiver,
the rifle further comprising:
an operating system extending forwardly along the
barrel and terminating in a barrel coupling including
a piston assembly coupled to the barrel for receiving
propelling gasses from the barrel, the piston assembly
having a cylinder with an open forward end, a piston
moveable between a retracted position and an extended
position within the cylinder, and an end plug
removably closing the open forward end of the cylinder
to permit passage of the piston therethrough when the
plug is removed.
a tubular handguard having a forward end, a rearward
end, a central void extending between the forward end
The parties agree that the purpose of this requirement is
to allow the user to perform various maintenance tasks, such as
modifying the gas intake or cleaning the operating system
components without disassembling the handguard.
2

3

and the rearward end, and a channel extending
therealong adjacent the central void, the tubular
handguard received about the barrel with the channel
providing clearance for the operating system and the
forward end being open to permit access to the barrel
coupling and end plug of the operating system; and
a barrel nut coupling the barrel to the receiver, and
the tubular handguard encircling the barrel is
received about and coupled to the barrel nut.
Doc. no. 1-1 at 22, Claim 1 (emphasis added).

The ‘722 patent

shows a view of the tubular handguard surrounding the barrel
with the forward end being open to permit access to components
of the operating system in Figure 9.

Figure 9 is reproduced

below with a graphic (rectangle) added by the court to identify
the open forward end of the handguard:

Doc. no. 1-1 at 7, Fig. 9.3

The end plug itself can be seen in Figure 9, immediately
above the barrel and extending past the handguard.
3

4

Ruger moves for summary judgment, arguing that it does not
infringe the ‘722 patent because its accused rifles do not have
a handguard with “the forward end being open to permit access to
the barrel coupling and end plug of the operating system.”4
Davies disagrees with that argument.

Because the construction

of the claim is relevant to whether certain of SIG Sauer’s
rifles are covered by the patent’s claims, the court allowed SIG
Sauer to brief the claim construction issue, and allowed Davies
to respond to SIG Sauer’s brief.

The court held a hearing on

Ruger’s motion on December 2, 2016, during which Davies, Ruger,
and SIG Sauer presented argument and/or evidence.
Standard of Review
“Evaluation of summary judgment of noninfringement is a
two-part inquiry: first, a court construes the scope and meaning
of the asserted patent claims, and then compares the construed
claims to the accused product.”

Medgraph, Inc. v. Medtronic,

Inc., 843 F.3d 942, 949 (Fed. Cir. 2016); see also Markman v.
Westview Instruments, Inc., 517 U.S. 370, 384-85 (1996).

The

Two additional claims contain identical language but
describe access to other components of the rifle’s operating
system. See doc. no. 1-1 at 22, Claim 5 (forward end of the
handguard being open to permit access to the piston assembly);
id. at 22, Claim 8 (forward end of the handguard being open to
permit access to the barrel coupling). For simplicity, the
court references only Claim 1. Its construction of the claim
language and summary judgment determinations apply equally to
Claims 5 and 8.
4

5

construction of patent claims is a matter of law exclusively for
the court.

UCB, Inc. v. Yeda Research and Dev. Co., Ltd., 837

F.3d 1256, 1259 (Fed. Cir. 2016).

The determination of

infringement, however, is a question of fact.

Bai v. L & L

Wings, Inc., 160 F.3d 1350, 1353 (Fed. Cir. 1998).

As such, the

court should grant summary judgment of noninfringement only when
it determines that, after construction of the claim and drawing
all reasonable factual inferences in favor of the nonmovant, no
rational factfinder could find that the accused products
infringe the patent at issue.

Medgraph, 843 F.3d at 949.

Discussion
I.

Claim Construction
In construing the scope and meaning of patent claim terms,

a court looks first to the evidence intrinsic to the patent.
Astrazeneca AB v. Mut. Pharm. Co., Inc., 384 F.3d 1333, 1336-37
(Fed. Cir. 2004).

The court begins by looking to “the claim

language itself to define the scope of the patented invention,”
and to the patent’s specification “[w]hen the claim language
itself lacks sufficient clarity to ascertain the scope of the
claims.”

Chimie v. PPG Indus., Inc., 402 F.3d 1371, 1377 (Fed.

Cir. 2005) (internal quotation marks and citation omitted).
Finally, the prosecution history, if in evidence, is examined
“to discern the applicant’s express acquiescence with or
6

distinction of the prior art as further indication of the scope
of the claims.”

Id.

Though “less significant than the intrinsic record” to
claim construction, the court may also “rely on extrinsic
evidence, which consists of all evidence external to the patent
and prosecution history, including expert and inventor
testimony, dictionaries, and learned treatises.”

Phillips v.

AWH Corp., 415 F.3d 1303, 1317 (Fed. Cir. 2005) (internal
quotation marks and citation omitted).

“[E]vidence extrinsic to

the patent is useful insofar as it ‘can shed useful light on the
relevant art—and thus better allow a court to place itself in
the shoes of a person of ordinary skill in the art’ reading the
claims alongside the rest of the specification.”

Astrazeneca,

384 F.3d at 1337 (quoting Vanderlande Indus. Nederland BV v.
Int’l Trade Comm’n, 366 F.3d 1311, 1318 (Fed. Cir. 2004)).
“Relying on extrinsic evidence to construe a claim is ‘proper
only when the claim language remains genuinely ambiguous after
consideration of the intrinsic evidence.’”

Interactive Gift

Exp., Inc. v. Compuserve Inc., 256 F.3d 1323, 1332 (Fed. Cir.
2001) (quoting Bell & Howell Document Mgmt. Prods. Co. v. Altek
Sys., 132 F.3d 701, 706 (Fed. Cir. 1997)).
Both Ruger and Davies assert that formal claim construction
is unnecessary because the claim limitation of a tubular

7

handguard with “the forward end being open to permit access to
the barrel coupling and end plug of the operating system” uses
common terminology, and a construction of the limitation beyond
the plain and ordinary meaning of its terms would not aid the
jury.5

After considering the intrinsic evidence, the court

agrees that nothing in the intrinsic evidence suggests the
patentee intended those terms to carry some alternative
definition beyond their plain and ordinary meaning.
Claim construction, however, is still necessary.

Although

the parties agree on the definition of the terms in the “open to
permit access” limitation, they dispute the scope of the
limitation itself.

Therefore, the court must construe the claim

in order to settle the meaning of the disputed terms as they are
used in the ‘722 patent and the scope of the claims in which the
terms appear.

See O2 Micro Int’l Ltd. v. Beyond Innovation

Tech. Co., Ltd., 521 F.3d 1351, 1362-63 (Fed. Cir. 2008)
(Markman requires district courts to resolve disputes between
the parties as to claim terms’ meaning or scope).
There are two components of the “open to permit access”
limitation that are relevant to Ruger’s motion: “being open” and

The court will refer to this claim limitation as the
“‘open to permit access’ limitation.”
5

8

“to permit access.”

The court addresses the components

separately.
A.

“Being Open”

As discussed above, the parties agree that the phrase
“being open” invokes the plain and ordinary meaning of those
terms, and nothing in the intrinsic evidence suggests otherwise.
The parties, however, disagree as to whether the handguard on
the accused rifles is open under the plain and ordinary meaning
of that term.

Therefore, the court will “clarify and . . .

explain what the patentee covered by the claims, for use in the
determination of infringement.”

U.S. Surgical v. Ethicon, Inc.,

103 F.3d 1554, 1568 (Fed. Cir. 1997).
During the prosecution of the ‘722 patent, the examiner
twice rejected the patentee’s claim as obvious in light of the
combination of U.S. Patent No. 4,244,273 (“Langendorfer”) with
other patents.

See 35 U.S.C. § 103.

The Langendorfer patent

disclosed a rifle in which the forward end of the handguard
attached to the rifle’s front sight assembly.

Mr. Davies, the

patentee, distinguished Langendorfer on the grounds that, unlike
the rifle disclosed in the ‘722 patent, the forward end of the
handguard on the Langendorfer rifle was not open: “Additionally,
Langendorfer does not teach an open end to the handguard.
handguards are attached at the front sight assembly.
9

The

There is

no provision, structure or possibility that the handguards of
Langendorfer can be open at the forward end.”
12.

Doc. no. 52-16 at

The patentee later noted that “[e]limination of the front

sight assembly to provide an open fronted handguard would render
it inoperable for its intended purpose.”

Id. at 13.

The patentee’s invocation of the term “open” in this manner
indicates that the forward end of the handguard on the
Langendorfer rifle is not open because it is attached to another
portion of the rifle, i.e., the front sight assembly.

It also

indicates that the forward end of the handguard on the
Langendorfer rifle would be open were it not attached to the
front sight assembly.
Thus, the prosecution history confirms that the plain and
ordinary meaning of the phrase “being open” is properly applied
to the “open to permit access” limitation.

The court agrees

with the parties that the phrase “being open” is clear in the
context of the ‘722 patent without the need for elaboration.

To

the extent the parties advance an argument suggesting that the
plain and ordinary meaning of the phrase “being open” is
inconsistent with the prosecution history discussed above, that
argument is without merit.

10

B. “To Permit Access”
The court next turns to the phrase “to permit access.”
Although the parties agree that the phrase should be given its
plain and ordinary meaning, they again dispute the scope of the
limitation.
Davies refers at various points in its objection to the
phrase “to permit access” as meaning “does not in any way
prevent access,” doc. no. 52-1 at 15, and “without any portion
of the handguard preventing access,” id. at 16.

Thus, Davies

appears to assert that the phrase “to permit access” has the
plain and ordinary meaning of “not preventing access.”
The court disagrees with that assertion.

First, that

meaning ignores the word “to” at the beginning of the phrase “to
permit access,” which suggests that the handguard’s forward end
is open for the purpose of providing access to the operating
system’s components.

See Innova/Pure Water, Inc. v. Safari

Water Filtration Sys., Inc., 381 F.3d 1111, 1119 (Fed. Cir.
2004) (“[A]ll claim terms are presumed to have meaning in a
claim.”).
Second, Davies’ interpretation of the plain meaning of the
phrase “to permit access” would seemingly require a finding that
any rifle with an open-fronted handguard could infringe the ‘722
patent, regardless of how the user accessed the operating system

11

components.

For example, under Davies’ proposal, a rifle with

its operating system components at the rear of and behind the
handguard could still infringe the ‘722 patent if it had a
handguard with an open forward end, because the handguard does
not prevent access to the operating system components.

Nothing

in the intrinsic evidence supports so broad a definition.
Instead, the ‘722 patent’s prosecution history shows that
the patentee contemplated that the open forward end of the
handguard would provide access to the operating system’s
components.

See doc. no. 64-5 at 12 (noting that the “open end

of the channel provides access to the barrel coupling”); see
also doc. no. 52-16 at 14 (“Again this specifies that the piston
can be removed from the forward end . . . .”).

This

construction is further supported by “the grammatical structure
of the claim language itself,” HowLink Glob. LLC v. Network
Commc’ns Int’l Corp., 561 F. App’x 898, 903 (Fed. Cir. 2014),
because the use of the infinitive, “to permit,” necessarily
means “in order to permit.”

Thus, the prosecution history shows

that permitting access to the operating system’s components is
the reason for the handguard’s forward end being open.
Although the parties assert that the phrase “to permit
access” invokes its plain and ordinary meaning and that the
court need not construe the phrase beyond the original language,

12

Davies’ briefing suggests that some clarification of the
phrase’s meaning is necessary.

Therefore, the court construes

the phrase “to permit access” to mean “for the purpose of
permitting access.”
C.

Summary

The court construes the “open to permit access” limitation
of Claim 1 to mean a tubular handguard with “the forward end
being open for the purpose of permitting access to the barrel
coupling and end plug of the operating system.”
II.

Infringement
“In order ‘to prove infringement, the patentee must show

that an accused product embodies all limitations of the claim
either literally or by the doctrine of equivalents.’”

Millipore

Corp. v. W.L. Gore & Assocs., Inc., 750 F. Supp. 2d 253, 271 (D.
Mass. 2010) (quoting Amgen Inc. v. F. Hoffman–LA Roche Ltd., 580
F.3d 1340, 1374 (Fed. Cir. 2009) (alterations omitted)).
Accordingly, the court may grant summary judgment of noninfringement only if, upon construction of the claims and with
all reasonable factual inferences drawn in favor of the nonmovant, there is no genuine issue as to whether the accused
product is encompassed by the patent claims either literally or
under the doctrine of equivalents.

13

Novartis Corp. v. Ben Venue

Labs., Inc., 271 F.3d 1043, 1046 (Fed. Cir. 2001); see also Bai,
160 F.3d at 1353-54.
A.

Literal Infringement

“To establish literal infringement, every limitation set
forth in a claim must be found in an accused product, exactly.
Thus, if any claim limitation is absent from the accused device,
there is no literal infringement as a matter of law.”

Becton,

Dickinson and Co. v. Tyco Healthcare Grp., LP, 616 F.3d 1249,
1253 (Fed. Cir. 2010) (internal quotation marks, citations, and
alterations omitted).

“Literal infringement of a properly

construed claim is a question of fact.”

Applied Med. Res. Corp.

v. U.S. Surgical Corp., 448 F.3d 1324, 1332 (Fed. Cir. 2006).
Therefore, the court must determine whether, after resolving all
inferences in favor of the patentee, a reasonable jury could
find literal infringement.

Akzo Nobel Coatings, Inc. v. Dow

Chem. Co., 811 F.3d 1334, 1341 (Fed. Cir. 2016).
As shown in the manual for Ruger’s SR-556 rifle, one of the
accused rifles, the lower portion of the forward end of the
rifle’s handguard extends past the upper portion:

14

Doc. no. 52-11 at 11-12.6

The piston assembly and end plug are

atop the barrel coupling, which is attached to the barrel of the
rifle:

The parties agree that, for purposes of this motion, the
other accused rifle, the SR-762 AR-style rifle, has the same
features as the SR-556 AR-style rifle.
6

15

Id. at 11.7

When the rifle is fully assembled, a portion of the

operating system sits on top of the lower portion of the
handguard, leaving certain parts of the barrel coupling, as well
as the end plug, in front of the handguard:

Doc. no. 49-4 at 4.
Ruger argues that there is no genuine issue of material
fact as to whether the accused rifles literally infringe the
‘722 patent because the accused rifles’ handguard is not open to
permit access to operating system components.

Davies disagrees.

Rather, according to Davies, the Ruger handguard “cuts away to
allow the barrel coupling and the end plug of the rifle to be

At the December 2 hearing, the parties disagreed over what
part of the components attached to the barrel represented the
barrel coupling in the picture above. Ruger asserted that the
barrel coupling consisted only of the front portion of the
components directly wrapped around the barrel. Davies asserted
that everything other than the end plug and the front sight
(which sits above the other components and stands straight up)
represents the barrel coupling. At this stage, because the
court is obligated to give Davies every reasonable inference,
the court assumes without deciding that Davies’ assertion is
correct.
7

16

accessed without restriction from the handguard.”

Doc. no. 52-1

at 15.
If the ‘722 patent claimed only a handguard, then Davies’
argument that the forward end of the accused rifles’ handguard
is open may have merit.

The ‘722 patent, however, claims a

rifle and, therefore, the court must look to whether the fully
assembled rifle meets the limitations of the asserted claims.
See, e.g., Sunbeam Prods., Inc. v. HoMedics, Inc., 412 F. App’x
263, 268 (Fed. Cir. 2010) (holding that the patent at issue
“claims a utility scale, not an unassembled scale or a method of
assembling a scale, so the relevant state for purposes of
infringement is the fully assembled scale”).
When assembled, the barrel coupling and the end plug of the
operating system sit within and/or extend past the cut-away
portion of the forward end of the handguard.

By doing so, those

components block the forward end of the handguard.

In other

words, when the accused rifles are assembled, the forward end of
the handguard is not “open to permit access” to the relevant
components of the operating system.
Davies contends that because the lower portion of the
handguard on the accused rifles extends past the upper portion,
the handguard is open.

As discussed above, however, that

argument is directly contradicted by the ‘722 patent’s

17

prosecution history.

The patentee distinguished the

Langendorfer rifle by asserting that the forward end of the
Langendorfer handguard is not “open” if it is obstructed by or
attached to another portion of the rifle, including operating
system components.

Doc. no. 52-16 at 12.

Here, when assembled, the forward end of the accused
rifles’ handguard is obstructed by and attached to the barrel
coupling and end plug.

Thus, when assembled, the forward end of

the accused rifles’ handguard is not “open.”

Therefore, even

giving Davies every reasonable inference, the accused rifles do
not literally infringe the ‘722 patent.

Accordingly, Ruger is

entitled to summary judgment as to literal infringement.
B.

Doctrine of Equivalents

Ruger also seeks summary judgment of noninfringement under
the doctrine of equivalents.

Under the doctrine of equivalents,

a product that does not literally infringe the express terms of
a patent claim may nonetheless be found to infringe if there is
“equivalence” between the elements of the accused product and
the claimed elements of the patented invention.

See Graver Tank

& Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605, 609 (1950).
“[T]he doctrine of equivalents must be applied to individual
elements of the claim, not to the invention as a whole.”

18

Warner–Jenkinson Co., Inc. v. Hilton Davis Chem. Co., 520 U.S.
17, 29 (1997).
In applying the doctrine of equivalents, the court must ask
“whether an asserted equivalent represents an ‘insubstantial
difference’ from the claimed element, or ‘whether the substitute
element matches the function, way, and result of the claimed
element.’”

Deere & Co. v. Bush Hog, LLC, 703 F.3d 1349, 1356

(Fed. Cir. 2012) (quoting Warner-Jenkinson, 520 U.S. at 40).
Thus, to be awarded summary judgment of noninfringement under
the doctrine of equivalents, defendant must show that, giving
the patentee every reasonable inference, the accused products do
not meet each prong of the function-way-result test or the
insubstantial differences test.

Augme Techs., Inc. v. Yahoo!

Inc., 755 F.3d 1326, 1336 (Fed. Cir. 2014).
There are certain limitations to the doctrine of
equivalents.

Ruger invokes two of them.

One such limitation is

prosecution history estoppel, whereby “the surrender of subject
matter during patent prosecution creates a presumption that the
patentee is precluded from recapturing that subject matter
through the doctrine of equivalents.”

AquaTex Indus., Inc. v.

Techniche Sols., 479 F.3d 1320, 1325 (Fed. Cir. 2007).

As

another, “if a court determines that a finding of infringement
under the doctrine of equivalents ‘would entirely vitiate a

19

particular claim[ed] element,’ then the court should rule that
there is no infringement under the doctrine of equivalents.”
Lockheed Martin Corp. v. Space Sys./Loral, Inc., 324 F.3d 1308,
1321 (Fed. Cir. 2003) (quoting Bell Atl. Network Servs., Inc. v.
Covad Commc’ns Grp., Inc., 262 F.3d 1258, 1280 (Fed. Cir.
2001)).
Ruger does not address whether its accused rifles meet the
“open to permit access” limitation via equivalence, either by
way of the insubstantial differences test or the function-wayresult test.

Instead, Ruger argues only that both prosecution

history estoppel and vitiation require a finding that the
accused rifles do not infringe the ‘722 patent by virtue of the
doctrine of equivalents.
1.

Prosecution History Estoppel

It is well-settled that “[t]he doctrine of equivalents
allows the patentee to claim those insubstantial alterations
that were not captured in drafting the original patent claim but
which could be created through trivial changes.”

Festo Corp. v.

Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd, 535 U.S. 722, 733
(2002) (“Festo I”).

“‘However, prosecution history estoppel may

bar the patentee from asserting equivalents if the scope of the
claims has been narrowed by amendment during prosecution.’”
Felix v. Am. Honda Motor Co., Inc., 562 F.3d 1167, 1181–82 (Fed.
20

Cir. 2009) (quoting Honeywell Int’l, Inc. v. Hamilton Sundstrand
Corp., 370 F.3d 1131, 1139 (Fed. Cir. 2004) (en banc)).

Whether

prosecution history estoppel bars the availability of the
doctrine of equivalents in an infringement action is a question
of law.

See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki

Co., Ltd., 344 F.3d 1359, 1367 (Fed. Cir. 2003).
“[P]rosecution history estoppel can occur during
prosecution in one of two ways, either (1) by making a narrowing
amendment to the claim (‘amendment-based estoppel’) or (2) by
surrendering claim scope through argument to the patent examiner
(‘argument-based estoppel’).”

Conoco, Inc. v. Energy & Envtl.

Int’l, L.C., 460 F.3d 1349, 1363 (Fed. Cir. 2006).
invokes amendment-based estoppel.8

Here, Ruger

Under that doctrine, “a

narrowing amendment made to satisfy any requirement of the
Patent Act may give rise to an estoppel.”
736.

Festo I, 535 U.S. at

“A patentee’s decision to narrow his claims through

amendment may be presumed to be a general disclaimer of the
territory between the original claim and the amended claim.”
Id. at 740.

The rationale is that “the inventor might

[otherwise] avoid the PTO’s gatekeeping role and seek to

Both in its reply memorandum and at the hearing on its
motion for summary judgment, Ruger expressly disclaimed
application of argument-based estoppel.
8

21

recapture in an infringement action the very subject matter
surrendered as a condition of receiving the patent.”

Id. at

734.
The patentee filed the application that matured into the
‘722 patent on June 14, 2006.
patent application.9

This application was a divisional

Its claims as originally filed were

directed at the composition of a rifle’s operating system.10

A divisional application is “‘[a] later application for an
independent or distinct invention, carved out of a pending
application and disclosing and claiming only subject matter
disclosed in the earlier or parent application.’” Pfizer, Inc.
v. Teva Pharm. USA, Inc., 518 F.3d 1353, 1360 (Fed. Cir. 2008)
(quoting Manual of Patent Examining Procedure § 201.06 (8th ed.,
Rev.5, 2006)).
9

10

For example, Claim 1 as originally filed recited:

In a rifle having an upper receiver carrying a bolt
carrier and a barrel attached to the upper receiver,
an operating system comprising:
a piston assembly coupled to the barrel for
receiving propelling gasses from the barrel, the
piston assembly including a piston moveable between a
retracted position and an extended position;
the piston being coupled to the bolt carrier for
movement of the bolt carrier from a closed position to
an open position as the piston moves from the
retracted position to the extended position; and
a resilient member positioned between the piston
and the bolt carrier for delaying and storing a
portion of force generated by the propelling gases.
Doc. no. 49-7 at 31.
22

None of the claims so much as mentioned a handguard.

On June

16, 2006, the patentee submitted a pre-examination amendment.
See doc. no. 52-13.

By that amendment, the patentee cancelled

all original claims and submitted a set of new claims: those
that eventually matured into the ‘722 patent.

These claims were

directed at a rifle with an operating system and a tubular
handguard.11

The new handguard limitation included the

requirement of “the end [of the handguard] being open to permit
access” to certain components.

Id. at 4.

Ruger argues that this amendment prevents Davies from
challenging as infringing any equivalent form of a handguard.
Prosecution history estoppel, however, does not apply unless the

For example, Claim 30 (which matured into Claim 1 of the
‘722 patent) recited:
11

A rifle having an upper receiver carrying a bolt
carrier and a barrel attached to the upper receiver,
the rifle further comprising:
an operating system extending along the barrel
and terminating in a barrel coupling; and
a tubular handguard having an end and a channel
extending therealong, the tubular handguard received
about the barrel with the channel providing clearance
for the operating system and the end being open to
permit access to the barrel coupling of the operating
system.
Doc. no. 52-13 at 3.
23

patentee makes an amendment that “narrows the patent’s scope.”12
Felix, 562 F.3d at 1182 (quoting Festo I, 535 U.S. at 736).
As demonstrated here, the patentee did not amend his prior
claims to “add” the handguard limitation and thereby narrow
them; he cancelled the prior claims and submitted a new set of
claims directed at a distinct invention—the handguard.13

This

is not the variety of “narrowing amendment” whereby the
patentee, by surrendering subject matter, may be estopped from
asserting its equivalent.

See, e.g., Desper Prods., Inc. v.

QSound Labs, Inc., 157 F.3d 1325, 1338 (Fed. Cir. 1998) (“In
determining the scope of what, if any, subject matter has been
surrendered, the standard is an objective one: what would a
reasonable competitor reading the prosecution history conclude
has been surrendered.”).

Were Ruger to have its way,

prosecution history estoppel would bar invocation of the
doctrine of equivalents for almost any claim that matures from a

The Supreme Court in Festo I set forth this principle in
the context of prosecution history disclaimer. However, the
“same general tenets” apply to both prosecution history
disclaimer and prosecution history estoppel, Trivascular, Inc.
v. Samuels, 812 F.3d 1056, 1063 (Fed. Cir. 2016) (citing cases),
and courts apply the principle to prosecution history estoppel,
see Felix, 562 F.3d at 1182; Regents of Univ. of Cal. v.
Dakocytomation Cal., Inc., 517 F.3d 1364, 1377 (Fed. Cir. 2008).
12

That the patentee ultimately reintroduced claim
limitations directed at the piston assembly in his October 7,
2009 amendments, see doc. no. 52-16 at 4, does not bear on the
effects of his earlier June 16, 2006 amendments.
13

24

divisional patent application.

That simply is not the law.

See, e.g., Invitrogen Corp. v. Clontech Labs., Inc., 429 F.3d
1052, 1078 (Fed. Cir. 2005) (prosecution history estoppel did
not apply to a divisional application).
Therefore, Ruger has not shown that prosecution history
estoppel bars a claim under the doctrine of equivalents for the
handguard limitation, including the “open to permit access”
limitation.
2.

Vitiation

The concept of vitiation derives from the requirement that
the doctrine of equivalents must be applied to claims “on an
element-by-element basis,” so that every claimed element of the
invention—or its equivalent—is present in the accused product.
Warner–Jenkinson, 520 U.S. at 40.

“‘[I]f a theory of

equivalence would entirely vitiate a particular claim element,
partial or complete judgment should be rendered by the court.’”
Power Integrations, Inc. v. Fairchild Semiconductor Int’l, Inc.,
843 F.3d 1315, 1344 (Fed. Cir. 2016) (quoting Warner-Jenkinson,
520 U.S. at 40).
“Of course, in every case applying the doctrine of
equivalents, at least one claimed element is not literally
present in the accused product.”

Deere, 703 F.3d at 1356.

“Thus, the doctrine of equivalents, by its very nature, assumes
25

that some element is missing from the literal claim language but
may be supplied by an equivalent substitute.”

Id.

Vitiation is

“a legal determination that the evidence is such that no
reasonable jury could determine two elements to be equivalent.”
Brilliant Instruments, Inc. v. Guidetech, LLC, 707 F.3d 1342,
1347 (Fed. Cir. 2013) (internal quotation marks and citation
omitted); see also Charles Mach. Works, Inc. v. Vermeer Mfg.
Co., 723 F.3d 1376, 1380 (Fed. Cir. 2013) (“Saying that a claim
element would be vitiated is akin to saying that there is no
equivalent to the claim element in the accused device based on
the well-established ‘function-way-result’ or ‘insubstantial
differences’ tests.” (internal quotation marks, citation, and
alteration omitted)).
“There is no set formula for determining whether a finding
of equivalence would vitiate a claim limitation, and thereby
violate the all limitations rule.”

Freedman Seating Co. v. Am.

Seating Co., 420 F.3d 1350, 1359 (Fed. Cir. 2005).

“Rather,

courts must consider the totality of the circumstances of each
case and determine whether the alleged equivalent can be fairly
characterized as an insubstantial change from the claimed
subject matter without rendering the pertinent limitation
meaningless.”

Id.

26

Ruger argues that a jury could not find that the accused
rifles infringe the ‘722 patent under the doctrine of
equivalents without vitiating the limitation requiring the
handguard to have a forward end being “open to permit access.”
Specifically, Ruger argues that because its handguard could not
be considered “open” under any claim construction, any finding
of equivalency would read out that limitation.
As discussed above, the court agrees that the handguard in
the accused rifles does not satisfy the court’s construction of
the “open to permit access” limitation, and thus the accused
rifles do not literally infringe the claims of the ‘722 patent.
It is not so clear, however, that Ruger has demonstrated that
its rifles are “an entirely different structure” from that
claimed, doc. no. 49-1 at 16, such that the court can conclude,
as a matter of law, that a finding of equivalence would vitiate
the “open to permit access” limitation.
In support of its vitiation argument, Ruger likens its
rifles to the rifle of the Langendorfer patent, which the
patentee distinguished during prosecution.

In so doing, Ruger

appears to be relying on argument-based estoppel, a doctrine
distinct from vitiation and one that Ruger expressly disclaimed
in its reply memorandum and at the hearing.

27

Ruger’s argument goes like this.

The Langendorfer patent

discloses a rifle, the operating system components of which sit
outside of and in front of the handguard, which is shown in the
dotted lines on the left portion of the diagram below:

Doc. no. 52-18 at 2.

During prosecution of the ‘722 patent, the

patentee distinguished the Langendorfer rifle because it did not
have an open-fronted handguard.
Ruger argues that, like the Langendorfer rifle, “access to
the operating systems of [its] rifles occurs well in front of
the Ruger handguard.”

Doc. no. 49-1 at 16.

According to Ruger,

that shows that its handguard is not “open” in a manner that
permits access to the operating system components.

In other

words, Ruger argues that because the accused rifles contain the
same structure as the Langendorfer rifle, a finding that the
accused rifles infringe the ‘722 patent would vitiate the
requirement that the handguard be open.

28

Assuming without deciding that the accused rifles contain
the same structure as the Langendorfer rifle, Ruger fails to
explain how that similarity of structure would vitiate the “open
to permit access” limitation of the ‘722 patent as applied to
Ruger’s rifle.

In short, while the patentee’s representations

regarding the Langendorfer rifle during prosecution of the ‘722
patent may support a theory of argument-based estoppel, Ruger
has not shown that those representations support its argument
based on vitiation.

See, e.g., Tritek Techs., Inc. v. United

States, 67 Fed. Cl. 735, 752 (Fed. Cl. 2005), aff’d, 208 F.
App’x 869 (Fed. Cir. 2006) (noting the differences between
argument-based estoppel, which relies on representations made by
the patentee during the prosecution history, and vitiation,
which is a legal determination that application of the doctrine
of equivalents to this claim limitation would “effectively erase
that limitation from the claim”).
To support its vitiation argument, Ruger relies on Panduit
Corp. v. HellermannTyton Corp., 451 F.3d 819 (Fed. Cir. 2006).
In Panduit, the Federal Circuit Court of Appeals held that
vitiation precluded application of the doctrine of equivalents.
The patent at issue in Panduit disclosed a “modular offset power
box and communication extension for a multi-channel power and
communication wiring and raceway system.”

29

Id. at 821 (internal

quotation marks omitted).

Claim 1 of that patent “require[d] an

opening in an abutment portion through which wires may pass from
a trunking duct into an offset power box.”

Id. at 830.

In the

accused product, “the wall abutting the trunking duct [was]
solid with no cutaway,” and the wires in the accused product
circumvented the abutment.

Id. at 824.

The Court of Appeals

concluded that, “[t]o extend the scope of the claim to encompass
an accused device in which wires bypass the abutment portion
altogether would necessarily read the ‘opening’ limitation out
of the claim.”

Id. at 830.

Ruger contends that, similar to Panduit, application of the
doctrine of equivalents to this case would read the “open to
permit access” limitation out of Claim 1 in the ‘722 patent
because Ruger’s handguard is not open.

The holding of Panduit

may have supported Ruger’s argument if the relevant limitation
at issue in this case were simply a handguard with an open
forward end.

As the parties made clear in their filings and at

the hearing, however, the relevant limitation is a handguard
with a forward end “being open to permit access” to certain
components of the operating system.

Thus, while Ruger’s

handguard is not literally open, that fact does not necessarily
preclude application of the doctrine of equivalents to the “open
to permit access” limitation.

See Nova Biomedical Corp. v. i-

30

Stat Corp., 215 F.3d 1351, 1999 WL 693881, at *5 (Fed. Cir.
Sept. 3, 1999) (per curiam) (unpublished decision) (reversing
the district court’s grant of summary judgment of
noninfringement based on vitiation “because not every word in a
claim is a separate limitation . . . . [and] [t]he limitation
here includes many other components”); Perkin-Elmer Corp. v.
Westinghouse Elec. Corp., 822 F.2d 1528, 1533 n.9 (Fed. Cir.
1987) (“It is the limitation of a claim that counts in
determining both validity and infringement, and a limitation may
include descriptive terms . . . .”).
In Panduit, the court held that to find that an accused
device in which wires circumvent the abutment portion entirely
would render meaningless, and thus vitiate, the limitation that
the abutment portion have an opening for wires to pass through.
Panduit, 451 F.3d at 830.

In contrast, viewing the evidence in

the light most favorable to Davies, application of the doctrine
of equivalents to Ruger’s rifle would not render meaningless the
limitation of a tubular handguard being open to permit access to
operating system components.

Although the forward end of the

Ruger handguard is not “open” under the court’s claim
construction, the cut-out in the upper portion of the forward
end of the handguard allows the user to access operating system
components.

In other words, the Ruger handguard is designed to

31

allow access to the operating system components by having them
sit in a cut-out portion of the front end of the handguard.
Thus, applying the doctrine of equivalents to the Ruger
handguard does not read the “open to permit access” limitation
out of Claim 1.

Cordis Corp. v. Bos. Sci. Corp., 561 F.3d 1319,

1330 (Fed. Cir. 2009) (affirming district court’s finding that
an accused product’s “circular arcs” did not vitiate the
limitation that the product must have “corners”); Wright Med.
Tech., Inc. v. Ostenoics Corp., 122 F.3d 1440, 1442-45 (Fed.
Cir. 1997) (reversing summary judgment of lack of infringement
under the doctrine of equivalents because it was a question of
fact as to whether the element of “an intermedullary rod portion
adapted to . . . extend through the narrowest portion of the
human femur” could be met by equivalence with an accused
intermedullary rod that did not extend through the femur).14
For these reasons, Ruger has not persuaded the court that
the doctrine of vitiation applies here.15

Although at least a portion of the relevant operating
system components extends beyond the Ruger handguard, that fact
is not dispositive in Ruger’s favor. As discussed above, the
end plug in the rifle disclosed in the ‘722 patent extends past
the handguard.
14

For similar reasons, none of the other cases cited by
Ruger in support of its vitiation argument changes the court’s
analysis above.
15

32

3.

Infringement by Equivalence

Ruger argues only that prosecution history estoppel and
vitiation preclude a finding of infringement by virtue of the
doctrine of equivalents.

It does not argue that its products do

not infringe under either the insubstantial differences test or
the function-way-result test.

“An element in the accused

product is equivalent to a claimed element if the differences
between the two elements are ‘insubstantial’ to one of ordinary
skill in the art.”

Wi-LAN, Inc. v. Apple Inc., 811 F.3d 455,

463 (Fed. Cir. 2016) (quoting Warner–Jenkinson, 520 U.S. at 40).
One way of demonstrating this is to show, “on an element-byelement basis that ‘the accused product performs substantially
the same function in substantially the same way with
substantially the same result as each claim limitation of the
patented product.’”

Intendis GMBH v. Glenmark Pharm. Inc., USA,

822 F.3d 1355, 1360 (Fed. Cir. 2016) (quoting Crown Packaging
Tech., Inc. v. Rexam Beverage Can Co., 559 F.3d 1308, 1312 (Fed.
Cir. 2009)).
As discussed above, the design of the accused rifles’
handguard allows for access to the end plug and barrel coupling
because Ruger cut out the upper portion of the forward end of
the handguard.

The barrel coupling sits, at least in part,

within the cut-out portion of the handguard, and the design of

33

the handguard thereby allows the operator to clean the operating
system by accessing the end plug and barrel coupling without
disassembling the handguard.

Viewing the evidence in the light

most favorable to Davies, there is a genuine issue of material
fact as to whether the handguard in the accused rifles, while
not literally having a forward end “being open to permit
access,” performs substantially the same function in the same
way and with the same result as the one described in the ‘722
patent with respect to the “open to permit access” limitation.
Therefore, Ruger is not entitled to summary judgment with
respect to infringement under the doctrine of equivalents.
Conclusion
For the foregoing reasons, Sturm, Ruger & Company, Inc.’s
motion for summary judgment (doc. no. 49) is granted with
respect to literal infringement of the ‘722 patent, but denied
with respect to infringement of the ‘722 patent under the
doctrine of equivalents.
SO ORDERED.

__________________________
Landya McCafferty
United States District Judge
February 15, 2017
cc:
Laura L. Carroll, Esq.
Zachary Rush Gates, Esq.
Chloe F.P. Golden, Esq.
34

James F. Laboe, Esq.
Tod M. Melgar, Esq.
Robert H. Miller, Esq.
Glenn Schuyler Orman, Esq.
Michael J. Pisko, Esq.
Scott D. Stimpson, Esq.
Jonathan T. Suder, Esq.
Brian David Thomas, Esq.
Decker A. Cammack, Esq.

35