GLASTON CORPORATION v. HHH EQUIPMENT RESOURCES

IN THE UNITED STATES DISTRICT COURT

FOR THE MIDDLE DISTRICT OF NORTH CAROLINA

GLASTON CORPORATION, and )

UNIGLASS ENGINEERING OY )

)

Plaintiffs. )

)

v. ) 1:21-cv-942

)

SALEM FABRICATION TECHNOLOGIES )

GROUP, d/b/a HHH EQUIPMENT )

RESOURCES, )

)

Defendant. )

MEMORANDUM OPINION AND ORDER

THOMAS D. SCHROEDER, District Judge.

Plaintiffs allege infringement of two patents, United States

Patent No. 8,479,540 (the “‘540 Patent”) and United States Patent

No. 8,650,911 (the “‘911 Patent”), that detail a method and

apparatus for heating and tempering glass. The parties dispute

the meaning of several of the terms in the patents’ claims; and

Defendant contends certain claims are indefinite. The parties’

contentions have been briefed (Docs. 38, 39, 40, 45, and 46), and

the court held a claim construction hearing on February 23, 2024.

For the reasons set forth below, the court declines to find certain

challenged terms indefinite and adopts all of Plaintiffs’ proposed

constructions.

I. BACKGROUND

The ‘540 Patent (Docs. 14-1) and the ‘911 Patent (Doc. 14-2)1

are related patents held by Plaintiff Uniglass Engineering OY

(“Uniglass”) and licensed exclusively to Plaintiff Glaston

Corporation (“Glaston”) for its use in tempering glass (Doc. 14

¶¶ 12-14).2 Both patents pertain to tempering glass by heating it

“from above and below using different energy absorption

principles” so that the top and bottom of the glass are heated at

different rates, leading to better and more even tempering. (Doc.

14 ¶ 19; ‘540 Patent at 2:11-45.3) Specifically, the top surface

of the glass is heated with recirculated pressurized hot air taken

from inside the furnace, while the bottom surface of the glass is

heated with pressurized air taken from outside the furnace as well

as by means of electric resistors. (‘540 Patent at 2:11-26.)

These patents build upon prior art for glass tempering, including

WO Publication 97/44283, WO publication 01/32570 (“Vehmas

1 For ease of reference, the court cites to the column and line of the

patent number rather than the docket entry.

2 There is a pending motion to dismiss Plaintiff Glaston. (Doc. 57.)

Because the outcome of that motion would not affect construction of the

claim terms as to Plaintiff Uniglass, the court need not reach it now.

3 Apart from the claim terms themselves, the ‘540 Patent and the ‘911

patent are nearly identical, containing the same background,

specification, and figures with only a few differences in line numbering

and minor word changes. The parties have acknowledged as much. (See,

e.g., Doc. 38 at 6 n.1.) Therefore, when discussing the contents of

both patents, the court cites only to the ‘540 patent for simplicity’s

sake. When the discussion affects only one of the patents, the specific

patent at issue will be cited.

Patent”), and US 2002/0134109 (“Vitkala Patent”), which had

previously disclosed the heating of glass using air recirculated

from inside the furnace and using air from outside the furnace but

had never combined them for the differential heating of glass from

the top and bottom. The ‘540 Patent concerns the method for

heating the glass (Doc. 14 ¶ 40), while the ‘911 Patent focuses on

the apparatus for doing so (id. ¶ 21).

Plaintiffs contend that Defendant Salem Fabrication

Technologies Group, Inc., d/b/a HHH Equipment Resources (“Salem”)

has infringed on both patents directly and by assisting a third-

party’s infringement. (Doc. 14.) Namely, Plaintiffs allege that

Luoyang North Glass Technology Co. (“Northglass”), a non-party for

which Salem is an authorized agent, uses furnaces in its AU series

products that infringe Plaintiffs’ patents, that Salem contributed

to and induced this infringement, and that Salem independently

infringes the patents through its use, offer to sell, sale, and

importation of Northglass’s products. (Id. ¶¶ 1, 16-52.)

Plaintiffs contend that this infringement is willful, sufficient

to support an award of treble damages pursuant to 35 U.S.C. § 284.

(Id. ¶¶ 37, 52.) Salem denies infringement of either of the

patents and asserts counterclaims seeking declarations of non-

infringement and invalidity for both patents. (Doc. 24 at 14-26.)

Pursuant to Local Patent Rule 104.3, the parties filed a joint

claim construction statement, agreeing on the meaning of several

patent claims and disputing others. They agreed on the following

constructions:

•

A “means for blowing the pressurized air back to an

upper surface of the glass,” as recited in the ‘911

Patent, Claim 1, is a means plus function term covered

by 35 U.S.C. § 112(f), where the corresponding

structure is “upper side blowpipes and equivalents

thereof” and the function is “blowing the pressurized

air back to an upper surface of the glass.”

•

A “means for heating the air pressurized by the

compressor,” as recited in the ‘911 Patent, Claim 1,

is a means plus function term covered by 35 U.S.C. §

112(f), where the corresponding structure is “an

underside feed pipe arranged in the lower part of the

furnace and/or a separate heater and equivalents

thereof” and the function is “heating the air

pressurized by the compressor.”

(Doc. 32 at 12; Doc. 32-1.) They further identified several

disputed claim terms for resolution by the court. (Doc. 32 at 13-

25; Doc. 32-2.) After providing their proposed constructions and

the intrinsic and extrinsic evidence supporting their positions as

part of the joint document, as well as opening and responsive claim

construction briefing (Docs. 38, 40, 45, 46), the parties

stipulated to the withdrawal of certain claims for construction.

(Doc. 68).4 Therefore, the following claim terms are subject to

4 The parties represented to the court that the term “wherein the

pressurizing comprises turbocharging” no longer required construction,

as Plaintiffs had agreed not to claim infringement under the ‘540 Patent,

Claims 4, 7, 9, 11, 12, and 15, and Salem had agreed to withdraw its

counterclaims for declaratory judgment based on both non-infringement

and invalidity for those same claims. (Doc. 68 at 2.) In addition, the

parties informed the court that they had reached agreement on the

following construction: “hot air jets,” as recited in the ‘540 Patent,

Claim 1, means “air jets at elevated temperature.”

the parties’ dispute:

•

“the improvements consisting essentially of,” as

recited in the ‘540 Patent, Claim 1

•

“sucking [hot] air from inside the [tempering]

furnace,” as recited in the ‘540 Patent, Claim 1, and

in the ‘911 Patent, Claim 1

•

“controlled in a forced manner so as to heat at a

power level in accordance with a heating profile,” as

recited in the ‘540 Patent, Claims 3, 12, 13, 14

•

“heat, using forced control, at a power level in

accordance with a heating profile,” as recited in the

‘911 Patent, Claim 4

•

“from a starting moment of the heating,” as recited

in the ‘540 Patent, Claim 8

•

“a pressurization unit for pressurizing the air sucked

from inside the tempering furnace,” as recited in the

‘911 Patent, Claim 1

•

“the temperature of the glass follows a predetermined

heating curve,” as recited in the ‘540 Patent, Claims

3, 12, 13, and 14

•

“a control unit arranged to control the blowing of

pressurized air,” as recited in the ‘911 Patent,

Claim 2

The court held a claim construction hearing on February 23,

2024, during which the parties addressed the contested terms.

(Minute Entry 02/23/2024.) The dispute is thus submitted to the

court and is ready for decision.

II. ANALYSIS

In total, the parties dispute the terms of eight claims, which

can be grouped analytically into three categories: (1) terms that

require the court to engage in standard claim construction (i.e.,

each party submits a proposed construction); (2) terms that Salem

argues are indefinite; and (3) terms that Salem argues are means-

plus-function terms subject to the indefiniteness limitation of 35

U.S.C. § 112 ¶ 6 but Plaintiffs argue are structural terms not

subject to such limitation. (See Docs. 32-2, 38, 40, 45, 46.)

Each of these categories is governed by a different legal standard,

and each will be addressed in turn below.

A. Standard Claim Construction

Claim construction is a question of law for the court.

Markman v. Westview Instruments, Inc., 517 U.S. 370, 384, 389-91

(1996). The claims of a patent define the invention itself,

establishing the metes and bounds of what is protected by law.

Phillips v. AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005) (en

banc). “The construction of claims,” then, “is simply a way of

elaborating the normally terse claim language in order to

understand and explain, but not to change, the scope of the

claims.” Embrex, Inc. v. Serv. Eng’g Corp., 216 F.3d 1343, 1347

(Fed. Cir. 2000) (alterations and citation omitted); see U.S.

Surgical Corp. v. Ethicon, Inc., 103 F.3d 1554, 1568 (Fed. Cir.

1997).

Claim terms should be construed according to the meaning they

“would have to a person of ordinary skill in the art in question

at the time of the invention” (“POSA”). Phillips, 415 at 1313.

Claim construction begins with the language of the claims

themselves, Braintree Labs., Inc. v. Novel Labs., Inc., 749 F.3d

1349, 1354–55 (Fed. Cir. 2014) (citing Interactive Gift Express,

Inc. v. Compuserve Inc., 256 F.3d 1323, 1331 (Fed. Cir. 2001));

Phillips, 415 at 1313-14, and the terms are generally given their

ordinary and customary meaning as understood by a POSA at the time

the patent application was filed. Phillips, 415 at 1312-13. When

deciphering that meaning, courts “first look to, and primarily

rely on, the intrinsic evidence, including the claims themselves,

the specification, and the prosecution history of the patent[.]”

Sunovion Pharms., Inc. v. Teva Pharms. USA, Inc., 731 F.3d 1271,

1276 (Fed. Cir. 2013) (citing Phillips, 415 F.3d at 1315; Vitronics

Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)).

The patent specification in particular “is always highly relevant

to the claim construction analysis[,]” and “[u]sually, it is

dispositive; it is the single best guide to the meaning of a

disputed term.” Phillips, 415 F.3d at 1315 (quoting Vitronics, 90

F.3d at 1582). Beyond that, the prosecution history, which

includes the record of proceedings before the Patent and Trademark

Office, is also “often of critical significance in determining the

meaning of the claims.” Vitronics, 90 F.3d at 1582.

Where intrinsic evidence leaves the term open to either

proposed construction, the court may then 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.” Markman v. Westview

Instruments, Inc., 52 F.3d 967, 980 (Fed. Cir. 1995), aff’d, 517

U.S. 370 (1996). However, although extrinsic evidence may be

probative of a claim’s meaning, it is “less significant” and “less

reliable” than intrinsic evidence. Phillips, 415 F.3d at 1317-18

(quoting C.R. Bard, Inc. v. U.S. Surgical Corp., 388 F.3d 858, 862

(Fed. Cir. 2004)). For example, the opinions of experts can be

helpful in understanding how a POSA would understand a term, but

they are less useful when they are simply “conclusory, unsupported”

definitions, or when they contradict the intrinsic evidence. Id.

at 1318. Expert testimony in particular must be viewed with

caution because it is evidence “generated at the time of and for

the purpose of litigation and thus can suffer from bias that is

not present in intrinsic evidence.” Id. Moreover, this bias “can

be exacerbated if the expert is not one of skill in the relevant

art or if the expert’s opinion is offered in a form that is not

subject to cross-examination.” Id. In the end, there is “no magic

formula or catechism for conducting claim construction.” Id. at

1324. What matters is that the court “attach the appropriate

weight” to the evidence from the various sources, acknowledging

the value and limitations of each kind of evidence. Id.

In the present case, the parties submit only the following

for standard claim construction: “sucking hot air from inside the

furnace.” (‘540 Patent, Claim 1; ‘911 Patent, Claim 1.) The court

takes up that analysis below.

1. “sucking [hot] air from inside the [tempering]

furnace”

Plaintiffs’ Construction Defendant’s Construction

“creating a pressure “moving hot air outside the

differential to pull air at furnace via a vacuum”

elevated temperature from

inside the furnace”

(Doc. 32-2 at 3.) (Doc. 32-2 at 3.)

Claim 1 of the ‘540 Patent provides in full:

The invention claimed is:

1. In a method of heating glass, the method comprising

conveying glass through a tempering furnace during

a heating cycle so that the glass is heated from

above and below, the improvements consisting

essentially of

heating an upper surface of the glass by hot air

jets formed by sucking hot air from inside the

furnace, pressurizing the hot air and recycling the

pressurized hot air back to the upper surface of

the glass for the heating from above, and

blowing air which has been taken from outside the

furnace and which has been pressurized by a

compressor and heated onto a lower surface of the

glass for the heating from below.

(‘540 Patent at Claim 1 (emphasis added).) Similarly, Claim 1 of

the ‘911 provides in full:

The invention claimed is:

1. An apparatus for heating glass, the apparatus

comprising a tempering furnace comprising horizontal

rolls arranged to carry the glass and to form a

conveyor thereof, an upper side return pipe for

sucking air from inside the tempering furnace, a

pressurization unit for pressurizing the air sucked

from inside the tempering furnace, means for blowing

the pressurized air back to an upper surface of the

glass, a compressor for pressurizing air taken from

outside the furnace, a pipe system for conveying the

air pressurized by the compressor to a lower surface

of the glass, and means for heating the air

pressurized by the compressor.

(‘911 Patent at Claim 1 (emphasis added).) The parties dispute

the meaning of the term “sucking [hot] air from inside the

[tempering] furnace” in both phrases. (Doc. 32-2 at 3.)

At the core of the dispute is whether the air must move

outside the furnace before being returned to heat the top surface

of the glass. The parties agree that the claim term involves the

working of some form of pressure differential5 to create the

movement of air and that this air must be at an elevated

temperature. (Docs. 38 at 19-20; Doc. 40 at 21.) However, the

parties disagree as to the path the air flow must take, which

hinges on the interpretation of the word “from” in the claim term.

Salem contends that “from” indicates a pathway of flow that

begins “inside the furnace” and proceeds by moving the hot air

5 Salem characterizes this pressure differential as a “vacuum” and

contends this is consistent with Plaintiffs’ presentation of the term

in the specification and in their proposed construction. (Doc. 38 at

19-20.) Plaintiffs do not specifically refute the “vacuum”

characterization in their briefing, nor did they do so at oral argument.

However, Plaintiffs also did not specifically concede this point, so to

avoid overstating the extent to which the parties agree, the court uses

the broader term “pressure differential,” which encompasses the narrower

term “vacuum.”

outside the furnace. (Doc. 38 at 18.) As intrinsic support for

this construction, Salem points to Figure 1 of both patents:

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(*540 Patent at Fig. 1.) Specifically, Salem notes the depiction

of air moving from the body of the furnace [2] to a pressurization

unit [10] located outside that body through the upper side return

pipe [11], and it points to the corresponding description in the

specification for how the pressurization unit [10] sucks air “from

at least one point inside the furnace,” but

“[plreferably . . . from a middle line of the furnace 1 at the

ceiling of the furnace and from both ends of the furnace” through

the pipe [11]. (Id. at 18-19 (citing ‘540 Patent at 3:49-51).)

According to Salem:

In all embodiments, the air being sucked from the inside

of the furnace is being sent to a location different

11

from the location it was sucked from . . . . Thus, a

[POSA] would understand from the specification that

‘from’ not only describes the origin of the hot air, but

also the intended direction of the hot air.

(Id. at 20 (emphasis in original).) Salem further alleges that

this construction is consistent with the historical record,

specifically the Vehmas patent that is cross-referenced multiple

times in the ‘540 and ‘911 patents. (Id. at 20-21.) In terms of

extrinsic support, Salem relies primarily on the testimony of Mr.

Lee Fackelman, a “semi-retired” mechanical engineer with a B.S.

and master’s degree in mechanical engineering and nearly 40 years’

experience in the glass tempering industry (Doc. 40-12 at 4,5),

and whom Plaintiffs do not appear to challenge is qualified to

testify as to what a person skilled in the art for purposes of

this case would have known (Cf. Doc. 40 at 18-19 (attacking Mr.

Fackelman’s credibility without disputing his credentials or

experience).). Mr. Fackelman opines that “sucking” a fluid such

as air cannot occur within the same container and concludes, based

on the specification and prior art references, that a POSA would

understand the claim term to necessitate movement outside the

furnace. (Doc. 32-3 ¶¶ 80-85.) That testimony is consistent,

Salem argues, with several dictionary definitions of “from” that

indicate that the term entails a separation, a fact which its

proposed definition recognizes. (Id. at 22 (citing Docs. 38-5,

38-7, 38-8.) Finally, Salem argues that Plaintiffs disclaimed any

broader meaning for “from inside the furnace” in their opposition

to the petition for inter partes review, where they emphasized the

movement of air outside of the furnace as required. (Id. at 22

(citing Doc. 39-11 at 31-32).) For all these reasons, Salem argues

that its proposed construction, which limits the scope of the term

to instances where air moves outside the furnace, is correct and

should be adopted.

According to Plaintiffs, “from” merely indicates the origin

or source of the air, and coverage is not limited to instances

where air moves outside the furnace. (Doc. 40 at 21.) Contrary

to Salem’s position, Plaintiffs note that the source and the

destination of the air are both clearly defined in the patent as

written: the air must come from the inside of the furnace and go

to the upper surface of the glass for heating from above. (Id. at

21-22.) Plaintiffs argue that neither the claims nor the

specifications require that the air be moved outside as it travels

between that source and the destination, and adding such a

requirement is contrary to the history of the patent and its

prosecution. (Id. at 23 (“During prosecution, applicants

repeatedly distinguished over prior art showing the use of fresh

compressed air for the upper convection heating, stating ‘[u]pper

heating by sucking air from inside the furnace is, therefore

contrary to the [Vitkala reference] and its combination with any

reference, even that of Vehmas.’”) (internal citation omitted).)

Plaintiffs contend, moreover, that they never disclaimed devices

that retain air within the furnace in their patent or during

prosecution; on the contrary, they specifically asserted that “the

drawings and the description are illustrations of the invention

and details may vary within the scope of the claims.” (Doc. 46 at

13-14 (citing ‘540 Patent at 5:47-49).)

Plaintiffs argue that their construction more faithfully

represents the actual meaning of the claim term. They point out

that the word “from” throughout the patent and specification is

used to designate the source or origin, making their construction

more consistent with evidence internal to the patent. (Id. at 21-

22 (citing ‘540 Patent at 3:49-54, 4:34-35).) Plaintiffs also

claim their construction is similarly consistent with Figure 1, as

structural unit [1] indicates the whole of the furnace and

encompasses the pressurization unit [10].6 (Doc. 46 at 12-13.)

And as Plaintiffs noted at oral argument, the patent elsewhere

denotes instances when air must be moved or taken from outside the

furnace, as it does with the bottom-side heating, which invites

the inference that this term should not be interpreted in the same

way. (Doc. 89 at 11 (“In fact, if the patentees had intended to

say that upper side air should be taken outside the furnace, they

6 Plaintiffs alternatively argue that even if Figure 1 supports Salem’s

construction, it is but one embodiment of the claimed invention meant

to demonstrate, but not limit, how the patent may be executed. (Doc.

46 at 13.)

would have done it. In fact, they did do it elsewhere in the

claim. For the bottom side blowing, the claim says the air is

taken from outside the furnace. Because the same claim recites

both inside the furnace and outside the furnace, they are presumed

to have different meanings.”).) Thus, Plaintiffs argue, their

proposed construction better represents the term in the patent and

should be selected.

Plaintiffs’ proposed construction indeed better presents the

claim term in a way that helps “explain, but not . . . change, the

scope of the claims” at issue. Embrex, 216 F.3d at 1347

(alterations and citation omitted). As Plaintiffs point out, the

patent defines a source for the air — “inside the furnace” — and

a destination for it — “the upper surface of the glass” — and the

patent states that the air must be pressurized between these two

points. (See ‘540 Patent at 2:13-16.) However, the patent says

nothing of a specific path the air must take to carry out that

process between those points. In this sense, Salem’s proposed

construction adds a prerequisite to what actually appears on the

face of the patent by inserting the requirement that the air move

outside the furnace in order to narrow the patent’s scope. But

the critical feature the claim intends to protect is the source of

the air, which is specified to be “from inside the furnace” for

top-side heating as opposed to “from outside the furnace” for

bottom-side hearing, and not the path through which it travels.

(‘540 Patent at Claim 1.) Indeed, the path through which the air

travels seems to be of no obvious importance to the operation of

the invention.7 On the other hand, “from” is used repeatedly

throughout the specification to denote origin. (See ‘540 Patent

at 3:49-54, 4:34-35.) A POSA reading the claims in light of the

specification and patent history would therefore understand the

feature protected by the term “sucking hot air from inside the

furnace” to be the use of air that is recycled from inside the

furnace, not the route through which it travels. Plaintiffs’

construction is thus more appropriate than Salem’s.

Moreover, Salem’s arguments concerning Figure 1 and

Plaintiffs’ disclaimer are unavailing. Even assuming Figure 1

shows air traveling outside the furnace, as Salem proffers (Doc.

38 at 19), the Federal Circuit “has expressly rejected the

contention that if a patent describes only a single embodiment,

the claims of the patent must be construed as being limited to

that embodiment.” Liebel-Flarsheim Co. v. Medrad, Inc., 358 F.3d

898, 906 (Fed. Cir. 2004) (citing ACTV, Inc. v. Walt Disney Co.,

346 F.3d 1082, 1091 (Fed. Cir. 2003); Apex Inc. v. Raritan Comput.,

7 Salem has argued, through the testimony of Mr. Fackelman and at oral

argument, that the separation cannot be within the same container – here,

the inside of the furnace – which makes specification of the path

implicit and necessary to recite. (Doc. 32-3 at ¶ 80.) However, at no

point does Salem provide any reasoning to support that conclusion. When

considered alongside the fact that Mr. Fackelman never reviewed the

patent prosecution history (Doc. 40-11 at 51, 57-58, 75), this argument

is unpersuasive.

Inc., 325 F.3d 1364, 1377 (Fed. Cir. 2003); Altiris, Inc. v.

Symantec Corp., 318 F.3d 1363, 1373 (Fed. Cir. 2003); Tex. Digit.

Sys., Inc. v. Telegenix, Inc., 308 F.3d 1193, 1204–05 (Fed. Cir.

2002); Teleflex, Inc. v. Ficosa N. Am. Corp., 299 F.3d 1313, 1327

(Fed. Cir. 2002); SRI Int’l v. Matsushita Elec. Corp. of Am., 775

F.2d 1107, 1121 n. 14 (Fed. Cir. 1985) (en banc)). It is only

when “the patentee has demonstrated a clear intention to limit the

claim scope using ‘words or expressions of manifest exclusion or

restriction’” that courts should interpret patents to be narrowed

to the single embodiment described or depicted. Id. (quoting

Teleflex, 299 F.3d at 1327). As already noted, no other part of

the patent or its history reflects an intent to limit the pathway

through which air from inside the furnace must travel. Therefore,

Salem’s argument falls short of supporting its construction even

if the court accepts its interpretation of the figure.

Salem’s disclaimer argument fails for a similar reason: the

Federal Circuit has made clear that a disavowal requires

“expressions of manifest exclusion or restriction, representing a

clear disavowal of claim scope.” Epistar Corp. v. Int’l Trade

Comm’n, 566 F.3d 1321, 1335 (Fed. Cir. 2009) (quoting Teleflex,

299 F.3d at 1325). As Plaintiffs point out, nowhere in the patent,

the patent prosecution history, or their response to inter partes

review do they engage in such a disavowal. (Doc. 46 at 13-14).

In fact, the marked-up diagram that Salem cites as evidence of

Plaintiffs’ disclaimer in their inter partes review response only

serves to bolster Plaintiffs’ argument that what is actually

critical is the distinction between air taken from inside the

furnace for upper-side heating and air taken from outside the

furnace for lower-side heating. (Doc. 39-11 at 31-32.) Therefore,

Salem’s arguments fail to support its position.

For these reasons, the court rejects Salem’s proposed

construction and adopts Plaintiffs’ construction for the term

“sucking [hot] air from inside the furnace” as it appears in Claim

1 of the ‘540 and the ‘911 Patents. The term thus means “creating

a pressure differential to pull air at elevated temperature from

inside the furnace.” (Doc. 32-2 at 3.)

B. Indefiniteness

Salem challenges the majority of the disputed terms as being

indefinite. A patent claim is invalid for indefiniteness under 35

U.S.C. § 112 “if its claims, read in light of the specification

delineating the patent, and the prosecution history, fail to

inform, with reasonable certainty, those skilled in the art about

the scope of the invention.” Nautilus, Inc. v. Biosig Instruments,

Inc., 572 U.S. 898, 901 (2014). “The definiteness requirement

‘mandates clarity, while recognizing that absolute precision is

unattainable.’” Presidio Components, Inc. v. Am. Tech. Ceramics

Corp., 875 F.3d 1369, 1375 (Fed. Cir. 2017) (quoting Nautilus, 572

U.S. at 910). In other words, “[t]he definiteness requirement

must take into account the inherent limitations of language, but

at the same time, the patent must be precise enough to afford clear

notice of what is claimed, thereby apprising the public of what is

still open to them.” Fairfield Indus., Inc. v. Wireless Seismic,

Inc., No. 4:14-CV-2972, 2015 WL 1034275, at *4 (S.D. Tex. Mar. 10,

2015) (citing Nautilus, 572 U.S. at 907–911). As with claim

construction, the question of indefiniteness is a legal one for

the court to evaluate. Young v. Lumenis, Inc., 492 F.3d 1336,

1344 (Fed. Cir. 2007) ; ePlus, Inc. v. Larson Software, Inc., 700

F.3d 509, 517 (Fed. Cir. 2012) (“[I]ndefiniteness is a question of

law and in effect part of claim construction.”).

A key difference between claim construction and

indefiniteness inquiries, however, relates to burden of proof.

Under § 282 of the Patent Act of 1952, 35 U.S.C. § 282, a patent

is “presumed valid,” and the burden of proving invalidity for

indefiniteness rests on the party asserting such invalidity. 35

U.S.C. § 282(a); see Microsoft Corp. v. I4I Ltd. P’ship, 564 U.S.

91, 95 (2011); Takeda Pharm. Co. v. Zydus Pharms. USA, Inc., 743

F.3d 1359, 1366 (Fed. Cir. 2014). The challenger must prove

invalidity by clear and convincing evidence. Microsoft Corp., 564

U.S. at 95; Takeda Pharm. Co., 743 F.3d at 1366.

Originally, the parties disputed whether the case is ripe for

adjudication of the indefiniteness issue. In the joint claim

construction brief, Plaintiffs argued that an indefiniteness

challenge at the claim construction stage would be premature,

noting that fact discovery was underway and the record was

undeveloped. (Doc. 32 at 3-5.) Plaintiffs reiterated this belief

in their opening claim construction brief. (Doc. 40 at 18-20.)

Defendants contended that the indefiniteness inquiry is proper at

this stage, citing case law finding that the indefiniteness

question is “part of claim construction.” (Doc. 32 at 7 (citing

ePlus, Inc., 700 F.3d at 517; Ultra-Mek, Inc. v. United Furniture

Indus., Inc., Case No. 1:18CV281, 2019 WL 4723351, at *4-5

(M.D.N.C. Sept. 9, 2019); Workshare Tech., Inc. v. Litera Techs.,

LLC, No. 1:11CV285, 2013 WL 1314595, at *3 (M.D.N.C. Mar. 28,

2013); Volumetrics Med. Imaging, LLC v. Toshiba Am. Med. Sys.,

Inc., No. 1:05CV00955, 2011 WL 6934603, at *5-6 (M.D.N.C. Dec. 30,

2011); Akeva L.L.C. v. Adidas Am., Inc., No. 1:03CV01207, 2005 WL

6225278, at *20-21 (M.D.N.C. May 17, 2005)).)

Whatever merit there may have been to Plaintiffs’ procedural

argument, Plaintiffs do not dispute that the record now sits in a

different posture. (Doc. 89 at 34.) Fact discovery is closed,

expert testimony for claim construction has been submitted to the

court, and there is no additional evidence either party intends to

bring forth on the issue of indefiniteness. (Id.) Based on this

posture and these representations, the court finds that

consideration of Salem’s indefiniteness arguments is appropriate

at this time.

Salem maintains that five terms are indefinite, thus

rendering the patent invalid: “the improvements consisting

essentially of” (‘540 Patent at Claim 1); “controlled in a forced

manner . . . in accordance with a heating profile” (‘540 Patent at

Claims 3, 12, 13, 14) and “heat, using forced control . . . in

accordance with a heating profile” (‘911 Patent at Claim 4)8; “the

temperature of the glass follows a predetermined heating curve”

(‘540 Patent at Claims 3, 12, 13, 14); and “from a starting moment

of the heating” (‘540 Patent at Claim 8). Salem raises only

indefiniteness challenges to these terms and does not provide

alternative constructions to those proposed by Plaintiffs.

Accordingly, each claim term will be considered below.

1. “the improvements consisting essentially of”

Plaintiffs’ Construction Defendant’s Construction

Permits the inclusion of Indefinite

components or steps not listed

in the claim, provided they do

not materially affect the

basis and novel properties of

the invention.

(Doc. 32-2 at 1.) (Doc. 32-2 at 1.)

The term “the improvements consisting essentially of,” which

8 The parties represent that these terms are functional equivalents of

one another in the two patents, that they raise the same arguments for

and against invalidity, and that they can be considered together by the

court. (See Doc. 89 at 78, 79; see also Docs. 38, 40 (addressing the

two claim terms together in the same subsection of the briefs).)

appears in Claim 1 of the ‘540 Patent,9 is a transitory term that

both parties agree represents the middle ground between the open-

ended transitory term “comprising” and the closed-ended transitory

term “consisting of.” (See Doc. 38 at 9; Doc. 40 at 7-8.) The

phrase “consisting essentially of” in a patent permits the

inclusion of components not listed in the claim that do not

materially affect the basic and novel properties of the invention.

AK Steel Corp. v. Sollac & Ugine, 344 F.3d 1234, 1239 (Fed. Cir.

2003). The parties’ central dispute over this term is whether the

basic and novel properties anticipated by the ‘540 Patent are

sufficiently definite to be instructive, or whether they are

indefinite, thus rendering the entire patent invalid.

Salem argues that the term is indefinite because the basic

and novel properties of the invention are indefinite such that a

POSA would not know whether additional components he or she was

contemplating were infringing. Relying on the testimony of Mr.

Fackelman, Salem claims the ‘540 Patent’s specification identifies

five basic and novel properties recognizable to a POSA: (1) heating

selective glass “reasonably quickly”; (2) a “reasonably simple”

apparatus; (3) heating coated glass in a “controlled manner”; (4)

achieving “quite a high heating rate”; and (5) keeping the

temperature of the bottom of the furnace “quite low” during a

9 The full text of Claim 1 is laid out in the previous section.

continuous load situation. (Doc. 38 at 10 (citing Doc. 32-2

¶ 42).) According to Salem, each of these properties is somehow

“comparative” in nature (i.e., a term of degree), and where that

is true, Federal Circuit “case law is clear that the objective

boundaries requirement applies to terms of degree.” (Id. (quoting

Berkheimer v. HP Inc., 881 F.3d 1360, 1364 (Fed. Cir. 2018)).)

Salem argues that neither the specification nor the prosecution

history provides a POSA with any such objective method for

evaluating whether any one of the properties has been altered,

much less materially altered. (Id. at 10-11.) Therefore, because

“a [POSA] cannot ascertain the bounds of the basic and novel

properties of the invention,” Salem concludes, Claim 1 and the

terms that flow from it should be deemed indefinite, and the patent

should be declared invalid. (Id. (citing HZNP Meds. LLC v. Actavis

Lab’ys UT, Inc., 940 F.3d 680, 696 (Fed. Cir. 2019); Energizer

Holdings, Inc. v. Int’l Trade Comm’n, 435 F.3d 1366, 1369 (Fed.

Cir. 2006)).)

Plaintiffs dispute Salem’s arguments for indefiniteness on

several grounds. First, they note that Salem’s analysis conflates

the basic and novel properties of the invention with the basic and

novel advantages of the invention conferred by those properties.

(Doc. 46 at 5.) According to Plaintiffs, the characteristics

identified by Mr. Fackelman are not the basic and novel properties

of the invention. (Id.) Instead, Plaintiffs assert the basic and

novel properties are illuminated via the use of Jepson10 claiming,

which is a form of historically recognized patent recitation that

contains a preamble followed by a transition phrase such as

“comprising” or “consisting essentially of” and concludes with the

novel improvements over the prior art. (Doc. 40 at 8.) Here,

those properties are: (1) heating the upper surface of the glass

with recycled hot air from the furnace, and (2) blowing pressurized

air from outside the furnace on the lower surface of the glass.

(‘540 Patent at Claim 1.) Plaintiffs argue that the specification

supports the reading that these are the basic and novel properties

of the invention, while the specification points to the “features”

identified by Mr. Fackelman only as advantages or improvements

that flow from the “heating” and “blowing” Plaintiffs identified.

(Compare ‘540 Patent at 2:11-20 (“The idea underlying the invention

is that . . . [t]he upper surface of the glass is heated by hot

10 Jepson claiming originally arose out of Ex Parte Jepson, 243 O.G. 525

(Ass’t Comm’r Pat 1917). The practice has since been codified:

Where the nature of the case admits, as in the case of an improvement,

any independent claim should contain in the following order, (1) a

preamble comprising a general description of all the elements or steps

of the claimed combination which are conventional or known, (2) a phrase

such as “wherein the improvement comprises,” and (3) those elements,

steps and/or relationships which constitute that portion of the claimed

combination which the applicant considers as the new or improved portion.

37 C.F.R. § 1.75(e). It continues to be recognized as a commonplace

practice in patent cases. See, e.g., Ethicon Endo-Surgery, Inc. v. U.S.

Surgical Corp., 93 F.3d 1572, 1577 (Fed. Cir. 1996) (noting that in a

Jepson claim, “the inventive portion of the claim must lie in the clause

beginning: ‘the improvement comprising’”).

air jets formed by sucking air from inside the furnace and

pressurizing the hot air and recycling it back to the upper surface

of the glass. Furthermore, air which has been taken from outside

the furnace and which has been pressurized by a compressor and

heated is blown to the lower surface of the glass.”), 3:8-65

(describing structures for heating the upper side of the glass by

pressurizing air recirculated from the upper side of the furnace),

3:66-4:46 (describing structures for heating the lower surface of

the glass by pressurized air taken from outside the furnace), with

id. at 2:32-46 (stating that the advantages of the invention

conferred by the basic and novel features of the claimed method

include a reasonably quick heating of glass, a reasonably simple

apparatus, achieving a high heating rate and keeping the

temperature of the bottom of the furnace quite low).)

Plaintiffs likewise argue that Salem’s contention ignores the

prosecution history of the patent, in which the ‘540 Patent was

repeatedly distinguished over prior art based on the combination

of the “heating” and “blowing” features. Plaintiffs note that the

prosecution history in several instances focused on the

combination of heated, recirculated air for top-side heating and

blown, outside air for bottom-side heating as the basis for the

invention’s novelty and non-obviousness. (See, e.g., Doc. 40-3 at

273 (“[T]he rejection for obviousness under 35 USC 103 is traversed

by the teaching in Vitkala of fresh compressed air for both the

upper and lower convection heating. Upper heating by sucking air

from inside the furnace is, therefore[,] contrary to [Vitkala]”),

299 (“[T]he Vitkala publication teaches supplying air from outside

the furnace to heat both the upper and lower faces of the glass.

This is directly contrary to claim 1, which requires the heating

of the upper surface to consist essentially of air from inside the

furnace.”), 330 (“[T]he alternatives of recirculation of either

the upper or the lower convection blast stream while using

nonrecirculated blast stream on the opposite glass surface are not

any ‘alternatives’ of existing prior art but a new and unexpected

combination.”), 464 (demonstrating that the Board of Appeals

specifically found that it was not obvious to recirculate furnace

air to heat the top of the glass based on prior art showing the

use of outside air to heat the top of the glass).) Meanwhile,

Plaintiffs point out that Mr. Fackelman’s testimony is unsupported

by the prosecution history, as by his own admission he did not

consider or review the historical record when expressing opinions

on the patent. (See, e.g., Doc. 40-11 at 51 (“I don’t think the

prosecution histories affected me at all because I browsed them

quickly and I - the opinions that I have are based entirely on the

information about legal standards that counsel has taught me and

the patents themselves.”), 57-58 (“I didn’t study those big

prosecution histories and they’re the only prosecution histories

I have ever seen at all. . . . I don’t have any details or opinions

relating to the prosecution histories because I didn’t hardly pay

any attention to them.”), 75 (“I paid very little attention to

that prosecution history.”).)

Finally, Plaintiffs argue that Salem previously agreed with

their proposed construction on this term, and the Patent and

Trademark Appeals Board (“PTAB”) therefore found that Plaintiffs’

construction prevailed. Plaintiffs point to Mr. Fackelman’s

deposition (Doc. 40-11 at 66) as well as Salem’s petition to the

PTAB acknowledging the disputed claim term (Doc. 40-9 at 19-20) as

evidence to support this contention. Salem argues in response,

however, that the transition phrase was not in dispute before the

PTAB and that any of Salem’s prior statements about its

understanding of the patent are not evidence here as to its

meaning, rendering this argument unpersuasive. (Doc. 45 at 8.)

Instead, Salem maintains that even in its opening brief, it

asserted the five basic and novel properties it asserts in its

claim construction briefing, and those should be found to control

here. (Id.)

As an initial matter, Salem is correct that the proceedings

before the PTAB are not instructive on this issue. The PTAB

considers only questions of novelty and non-obviousness as part of

inter partes review, Inter Partes Review, U.S. Pat. & Trademark

Off., https://www.uspto.gov/patents/ptab/trials/inter-partes-

review (last visited Apr. 8, 2024), and the question of

indefiniteness of the term “the improvements consisting

essentially of” was not contested or considered.

Nevertheless, Salem has failed to show by clear and convincing

evidence that the term is indefinite and that the patent is

therefore invalid. Salem rests its entire argument on the

testimony of Mr. Fackelman, yet his testimony suffers all of the

credibility11 issues that Plaintiffs point out. Mr. Fackelman’s

failure to review the full history of the patent, which can be

critical to the understanding of its meaning, Vitronics, 90 F.3d

at 1582, coupled with his own testimony that his opinions come

from Salem’s counsel’s legal teachings, casts serious doubt on his

ability to provide reliable testimony as to the understanding of

these terms – and it is not enough on its own to constitute clear

and convincing evidence. Meanwhile, Plaintiffs offer more than

sufficient evidence not only to rebut Salem’s position but to find

affirmatively that the patent should be interpreted as a Jepson

claim with the “heating” and “blowing” steps being the basic and

novel properties of the invention.

Therefore, the court holds that the term “the improvements

consisting essentially of” is sufficiently definite. As a result,

11 District courts at the claim construction stage are authorized to make

credibility determinations, even on a written record of expert testimony.

Teva Pharms., 574 U.S. at 325-327. Here, the court has reviewed the

deposition transcripts and expert declarations provided to it, and it

has assessed the experts’ credibility in accordance with its power to

make subsidiary factual determinations that support its legal analysis.

Plaintiffs’ construction prevails, and the term will be understood

to include components or steps not listed in the claim so long as

they do not materially alter the “heating” and “blowing” properties

listed.

2. “controlled in a forced manner . . . in accordance

with a heating profile” and “heat, using forced

control . . . in accordance with a heating profile”

Plaintiffs’ Construction Defendant’s Construction

“controlled to heat at a power Indefinite

level in accordance with a

heating profile”

(Doc. 32-2 at 4.) (Doc. 32-2 at 4.)

Plaintiffs’ Construction Defendant’s Construction

“heat at a power level in Indefinite

accordance with a heating

profile”

(Doc. 32-2 at 6.) (Doc. 32-2 at 6.)

The term “controlled in a forced manner . . . in accordance

with a heating profile” appears in several terms in the ‘540

Patent. It first appears in Claim 3, which states in full:

3. A method as claimed in claim 2, wherein during the

blowing on the underside, the underside is heated by

the electric resistors controlled in a forced manner

so as to heat at a power level in accordance with a

heating profile, and during 5 the rest of a heating

cycle, the electric resistors are controlled by

thermoelements such that the temperature of the

glass follows a predetermined heating curve.

(‘540 Patent at Claim 3 (emphasis added).) It next appears in

Claim 12, which states in full:

12. A method as claimed in claim 11,

wherein the lower surface of the glass is heated from

below by means of electric resistors, and when the

blowing on the underside starts, heating effect

given by the electric resistors is increased,

wherein during the blowing on the underside, the

underside is heated by the electric resistors

controlled in a forced manner so as to heat at a

power level in accordance with a heating profile,

and during the rest of a heating cycle, the electric

resistors are controlled by thermoelements such that

the temperature of the glass follows a predetermined

heating curve,

wherein the blowing on the underside ends before the

heating cycle ends, and lasts maximally for 60% of

the heating cycle, and

wherein the blowing on the underside ends no later

than at 80% of the heating cycle.

(‘540 Patent at Claim 12 (emphasis added).) It also appears in

Claim 13 immediately following, which states in full:

13. A method as claimed in claim 10,

wherein the lower surface of the glass is heated from

below by means of electric resistors, and when the

blowing on the underside starts, heating effect

given by the electric resistors is increased,

wherein during the blowing on the underside, the

underside is heated by the electric resistors

controlled in a forced manner so as to heat at a

power level in accordance with a heating profile,

and during the rest of a heating cycle, the electric

resistors are controlled by thermoelements such that

the temperature of the glass follows a predetermined

heating curve,

wherein the blowing on the underside ends before the

heating cycle ends, and lasts maximally for 60% of

the heating cycle, and

wherein the blowing on the underside ends no later

than at 80% of the heating cycle.

(‘540 Patent at Claim 13 (emphasis added).) Finally, it appears

in Claim 14, which states in full:

14. A method as claimed in claim 1,

wherein the lower surface of the glass is heated from

below by means of electric resistors, and when the

blowing on the underside starts, heating effect

given by the electric resistors is increased,

wherein during the blowing on the underside, the

underside is heated by the electric resistors

controlled in a forced manner so as to heat at a

power level in accordance with a heating profile,

and during the rest of a heating cycle, the electric

resistors are controlled by thermoelements such that

the temperature of the glass follows a predetermined

heating curve,

wherein the blowing on the underside ends before the

heating cycle ends, and lasts maximally for 60% of

the heating cycle, and

wherein the blowing on the underside ends no later

than at 80% of the heating cycle.

(‘540 Patent at Claim 14 (emphasis added).)

The related term “heat, using forced control . . . in

accordance with a heating profile” appears only once in Claim 4 of

the ‘911 Patent, which states in full:

4. An apparatus as claimed in claim 3, wherein the

control unit is arranged to control the lower

electric resistors to heat, using forced control, at

a power level in accordance with a heating profile

simultaneously with the blowing of pressurized air

on the lower surface of the glass

(‘911 Patent at Claim 4 (emphasis added).)

As noted, the parties represented to the court that both of

these terms can be considered together. (Doc. 89 at 78-79.) As

with the other terms, Salem contends that they are indefinite,

while Plaintiffs provide a proposed construction and contend they

are sufficiently definite to be valid.

Salem contends that these terms are indefinite because they

fail to provide a POSA with sufficient detail to know whether he

is infringing on the protected heating processes. Salem posits

that when a claim “requires that an artisan make a separate

infringement determination for every set of circumstances in which

the composition may be used, and when such determinations are

likely to result in differing outcomes (sometimes infringing and

sometimes not), that construction is likely to be indefinite.”

(Doc. 38 at 14 (quoting Halliburton Energy Servs., Inc. v. M-I

LLC, 514 F.3d 1244, 1254-55 (Fed. Cir. 2008)).) Here, Salem argues

that heating glass “according to a heating profile” and using

“forced control” are distinct processes, but the patents fail to

provide direction to a POSA how to do both simultaneously. (Id.

at 13.) Salem further contends that the patents’ single

description of a heating profile is inconsistent with how a POSA

would have understood a heating profile under the prior art. (Id.

(citing ’540 Patent at 4:65-5:2).) Moreover, per the testimony of

Mr. Fackelman, Salem argues that invocation of both a heating

profile and forced control, which are two different ways to heat

glass, creates ambiguity and difficulty for a POSA, especially

without a recipe for a particular heating profile. (Id. (citing

Doc. 32-3 ¶¶ 49-52).) Given that a wide variety of factors such

as glass size, composition, thickness, and ambient environmental

factors would impact whether a certain “heating profile” would

properly heat a particular piece of glass “using forced control,”

Salem argues, the specification provides insufficient detail to

teach a POSA to heat glass using forced control in accordance with

a heating profile in different circumstances. (Id. at 13-14.)

Therefore, it concludes, the term should be invalidated for

indefiniteness.

Plaintiffs deny that the patent provides insufficient detail

on this point. According to Plaintiffs, the patents’

specifications provide clear descriptions that distinguish between

heating based on a heating profile and heating based on the control

of a thermoelement, and the claimed term language here clearly

refers to the former. (See ‘540 Patent at 4:49-5:46; ‘911 Patent

at 4:55-61, 5:1-3, 5:12-20.) In addition, Plaintiffs note that

the specifications and patent prosecution histories’ references to

the Vehmas Patent provide further instruction for a POSA seeking

to understand how this method and apparatus operate. (See Doc.

40-3 at 72 (explaining that “[w]hat is known as a heating profile

can be created for the furnace by means of electric resistors,

convection blowing having at the same time enabled the raising of

the furnace capacity”), 77-78 (noting that the Vehmas Reference

adds that “when the glass 4 arrives in the furnace, the upper

resistors 5 are on according to a predefined heating profile”).)

As Plaintiffs point out, Salem’s expert Mr. Renald Bartoe12 at the

inter partes review stage previously represented his opinion that

a POSA would have understood what a heating profile was based on

the information provided; that he or she would need to vary the

heating profile’s parameters across various dimensions based on

the type, size, and thickness of the glass to be tempered; and

generally how to make those variations. (Doc. 40 at 12-13 (citing

Doc. 40-5 ¶ 128).) While Plaintiffs concede Salem’s point that

the patents do not provide specific recipes for heating, they

contend they do not need to, as it is enough that a POSA would

know he needed a recipe and could determine one based on his

experience with the prior art. (Id. at 13 (citing In re Buchner,

929 F.2d 660, 661 (Fed. Cir. 1991); Hybritech, Inc. v. Monoclonal

Antibodies, Inc., 802 F.2d 1367, 1384 (Fed. Cir. 1986).)) Thus,

Plaintiffs contend, the term should not be deemed indefinite and

their proposed construction should control.

12 Mr. Bartoe holds a B.S. in biochemistry and, like Mr. Fackelman, has

over 40 years’ experience in the glass tempering and ceramics industry.

(Doc. 40-5 at 10-17.) Plaintiffs accept him as having expert

qualifications to offer opinions on the glass tempering industry and

what a POSA would have understood. (Cf. Doc. 40 at 18-19 (comparing Mr.

Bartoe’s findings against Mr. Fackelman’s while assuming both of their

qualifications in the industry to offer such findings).)

Salem again has not shown by clear and convincing evidence

that these terms are indefinite. Apart from the problems already

raised with relying on the testimony of Mr. Fackelman, Salem’s

arguments misconstrue the actual protections of the patents.

Though Salem acknowledged at oral argument that the patent did not

need to be tailored to a specific type of glass, it also asserted

that in order for these terms to be definite, some specific heating

profiles would need to be disclosed on the face of the patent.

(Doc. 89 at 80, 83-86.) As Plaintiffs pointed out, this

misunderstands what the patents actually seek to protect: it is

not the specific recipes (of which there would be scores, depending

on the type and application of the glass) that matter here, but

whether a POSA would know it needed to use some recipe to heat the

glass in accordance with the method recited and how to go about

determining what that recipe would be. (See id. at 88 (“These

claims and these patents aren’t directed to recipes for specific

kinds of glass. They are not directed to individual heating

profiles for particular glass tempering applications. This patent

does not need to provide a thousand different recipes or heating

profiles in order to support these claims.”).) There is ample

evidence in the record to suggest that a POSA would understand

this fact. The prosecution history and Salem’s own Mr. Bartoe

point out that the practice of creating heating profiles and the

variables to consider are already established under the prior

art — specifically the Vehmas patent — such that a POSA would have

sufficient knowledge to understand the terms here. (Doc. 40-3 at

72, 77-78; Doc. 40-5 ¶ 128.) While Salem argued that it would

take a person of greater than ordinary skill in the art to know

how to do this (Doc. 89 at 82), this blanket assertion without

additional support is not enough to carry the burden of showing

indefiniteness by clear and convincing evidence, and Mr.

Fackelman’s testimony likewise does not suffice to cross that

hurdle. Therefore, Salem has not shown that either of these terms

is indefinite and thus invalid as a matter of law.

Having reviewed Plaintiffs’ constructions for both terms, the

court adopts them. The term “controlled in a forced

manner . . . in accordance with a heating profile,” as it appears

in the ‘540 Patent, Claims 3, 12, 13, and 14, will be construed to

mean “controlled to heat at a power level in accordance with a

heating profile.” (Doc. 32-2 at 4.) The term “heat, using forced

control . . . in accordance with a heating profile,” as it appears

in the ‘911 Patent, Claim 4, will be construed to mean “heat at a

power level in accordance with a heating profile.” (Doc. 32-2 at

6.)

15. “the temperature of the glass follows a

predetermined heating curve”

Plaintiffs’ Construction Defendant’s Construction

“the temperature of the glass Indefinite

follows a heating curve

determined beforehand”

(Doc. 32-2 at 10.) (Doc. 32-2 at 10.)

Salem raises a near identical dispute over the term “the

temperature of the glass follows a predetermined heating curve” as

it does over the prior two terms.13 Salem does not address the

term separately and instead combines its arguments for the prior

two terms with this one. (See Doc. 38 at 12-15.) In essence, it

argues that “predetermined heating curve” is also indefinite

because there are no specific instructions for what to consider or

how to calculate the heating curve, and without these boundaries,

a POSA would have no understanding of when he was infringing. (See

Doc. 89 at 86-88.) It again offers the testimony of Mr. Fackelman

and supporting case law to support this contention. (Doc. 38 at

12-15 (citing Doc. 32-3 ¶¶ 55, 57).) Plaintiffs respond by noting

that the important term of limitation is that the curve must be

“predetermined,” or set beforehand, and so long as a POSA engaged

in the well-understood process of calculating a heating curve based

on the variables of the specific glass beforehand, he or she would

13 This term likewise appears in Claims 3, 12, 13, and 14 of the ‘540

Patent, which are recited in full above.

be infringing. (Doc. 40 at 13-15.) This is sufficiently clear on

the face of the patent, Plaintiffs contend, and they argue that

the term is therefore not indefinite for the same reasons as above.

The court agrees with Plaintiffs. As with the prior two

terms, the court here finds that Salem has not met its burden to

demonstrate that the term is indefinite by clear and convincing

evidence. Plaintiffs are correct that what matters is a POSA would

know to determine the heating curve ahead of time and he has the

skill from knowledge of the prior art to do so. In addition, the

‘540 Patent does provide one example of a predetermined heating

curve, creating an even stronger inference that a POSA would have

the information needed to understand and navigate the confines of

the patent. (See ‘540 Patent at Figure 2.)

Therefore, the court denies Salem’s indefiniteness challenge

here as well and, having reviewed Plaintiffs’ proposed

construction, adopts it. The term “the temperature of the glass

follows a predetermined heating curve,” as it appears in the ‘540

Patent, Claims 3, 12, 13, and 14, will be understood to mean “the

temperature of the glass follows a heating curve determined

beforehand.” (Doc. 32-2 at 10.)

16. “from a starting moment of the heating”

Plaintiffs’ Construction Defendant’s Construction

“when heating of the glass Indefinite

begins”

(Doc. 32-2 at 8.) (Doc. 32-2 at 8.)

Lastly in its indefiniteness arguments, Salem argues that the

term “from a starting moment of the heating” in Claim 8 of the

‘540 Patent is indefinite because it is not specific as to which

heating it refers. Claim 8 reads in full: “A method as claimed

in claim 5, wherein the blowing on the underside starts at a moment

of 25 to 405 from a starting moment of the heating.” (‘540 Patent

Claim 8 (emphasis added).) According to Salem, Claim 8 depends

from Claim 5,14 which depends from Claim 1, which recites two

distinct heatings: “heating from above and below.”15 (See Doc. 38

at 17.) As set out earlier, Claim 1 provides:

The invention claimed is:

1. In a method of heating glass, the method comprising

conveying glass through a tempering furnace during

a heating cycle so that the glass is heated from

above and below, the improvements consisting

essentially of

14 Claim 5 provides: “A method as claimed in claim 1, wherein the blowing

on the underside ends before the heating cycle ends, and lasts maximally

for 60% of the heating cycle.” (‘540 Patent at Claim 5.)

15 Salem also notes that apart from the convection heating described in

Claim 1 for the bottom side of the glass, there is also heating “by

means of electrical resistors” that takes place on the bottom side, which

is recited in Claim 2. (‘540 Patent at Claim 2.) Salem argues that

this further contributes to the confusion. (Doc. 45 at 9-10.)

heating an upper surface of the glass by hot air

jets formed by sucking hot air from inside the

furnace, pressurizing the hot air and recycling the

pressurized hot air back to the upper surface of

the glass for the heating from above, and

blowing air which has been taken from outside the

furnace and which has been pressurized by a

compressor and heated onto a lower surface of the

glass for the heating from below.

(‘540 Patent at Claim 1.) Salem then argues that Claim 8 is not

specific about which of the two heatings in Claim 1 the “starting

moment” is meant to refer and that the specification and

prosecution histories likewise do not illuminate this point. (Doc.

38 at 18.) Therefore, it argues, the claim term is indefinite

under the Nautilus standard. (Id.)

Plaintiffs rebut Salem’s argument by noting that a common

sense reading of the language of the claims makes clear that the

patent refers to the top-side heating. According to Plaintiffs,

Claim 1 recites a topside and a bottom-side heating. (‘540 Patent

at Claim 1.) They contend that Claim 8 refers to the delayed start

of “underside blowing” (the method for bottom-side heating), which

Plaintiffs argue logically means that the delayed start refers to

the only other heating step recited in Claim 1 — heating from

above — as it cannot start later than, or be delayed as to, the

same underside blowing. (Doc. 40 at 15.) Plaintiffs assert that

this reading is confirmed by the specification and the testimony

of Salem’s own expert, Mr. Bartoe. (Id. (citing ‘540 Patent at

Fig. 2, 5:6-27, 5:39-43; Doc. 40-5 at 89-90.) Therefore, they

contend, this term should be deemed sufficiently definite.

The court is persuaded by Plaintiffs’ logic and finds that

Salem has failed to demonstrate by clear and convincing evidence

that the term is indefinite. While Salem argues that Plaintiffs’

reasoning ignores the existence of a second type of bottom side

heating (namely, the heating of the lower surface of the glass

from below by means of electrical resistors), that other heating

is referenced in Claim 2 of the ‘540 Patent, which is outside of

the dependency chain of Claim 8. When the claim chains are read

together, Claim 8 necessarily refers to top-side heating described

in Claim 1 and not the same bottom-side heating it describes.

Therefore, the court declines to find this term is indefinite and,

having reviewed Plaintiffs’ construction, adopts it. The term

“from a starting moment of the heating,” as it appears in the ‘540

Patent, Claim 8, will be understood to mean “when heating of the

glass begins.” (Doc. 32-2 at 8.)

C. Means-Plus-Function and Section 112, Paragraph 6

Finally, there is a subset of the claim terms that Salem

contends are indefinite and which Salem argues are means-plus-

function terms. Means-plus-function claim limitations, authorized

by 35 U.S.C. § 112 ¶ 6, allow a patentee to draft claims “as a

means or step for performing a specified function without the

recital of structure, material, or acts in support thereof[.]”

This provision allows “patentees to express a claim limitation by

reciting a function to be performed rather than by reciting

structure for performing that function[.]” Williamson v. Citrix

Online, LLC, 792 F.3d 1339, 1347 (Fed. Cir. 2015) (en banc). In

this way, § 112 ¶ 6 allows a patentee to claim “not what an

invention is but what an invention does.” Stephen Winslow, Means

for Improving Modern Functional Patent Claiming, 98 Geo. L.J. 1891,

1892 (2010) (emphasis omitted).

The parties here dispute both whether certain terms are means-

plus-function terms and, if so, whether they clear the limitation

set by § 112 ¶ 6. When a claim term uses the word “means” and

accompanies it with a description of a component’s function, there

is a rebuttable (although not a “strong”) presumption that the

term is a means-plus-function phrase under § 112 ¶ 6, and the party

alleging otherwise has the burden of overcoming it. Williamson,

792 F.3d at 1348–49. Conversely, where a claim does not use the

word “means,” there is a rebuttable presumption of equal strength

that the term is not a means-plus-function term, and the burden to

overcome it rests with the party seeking to the application of

§ 112 ¶ 6. Id. The presumption can be overcome and § 112 ¶ 6

will apply “if the challenger demonstrates that the claim term

fails to recite sufficiently definite structure or else recites

function without reciting sufficient structure for performing that

function.” Id. at 1348 (internal quotation marks omitted). The

Federal Circuit has explained that “[g]eneric terms such as

‘mechanism,’ ‘element,’ ‘device,’ and other nonce words that

reflect nothing more than verbal constructs may be used in a claim

in a manner that is tantamount to using the word ‘means’” and

therefore may trigger § 112 ¶ 6. Id. at 1350.

The inquiry for the court is whether “the claim language,

read in light of the specification, recites sufficiently definite

structure” such that it avoids being defined merely by its

function. Robert Bosch, LLC v. Snap-On Inc., 769 F.3d 1094, 1099

(Fed. Cir. 2014); see Williamson, 792 F.3d at 1349. While a

specification that describes only how a component part interacts

with other parts of the invention may be sufficient to impart

structure, the specification must still implicitly limit the claim

term to some specific structure or structures. See Inventio AG v.

ThyssenKrupp Elevator Ams. Corp., 649 F.3d 1350, 1358–59 (Fed.

Cir. 2011) (“The written descriptions also show how the elements

are connected together and to the elevator control and computing

unit components of the elevator system.”), overruled by

Williamson, 792 F.3d 1339 (Fed. Cir. 2015); cf. Media Rights

Techs., Inc. v. Capital One Fin. Corp., 800 F.3d 1366, 1372–73

(Fed. Cir. 2015) (applying § 112 ¶ 6 when the only structural

description in the specification was but one example of the

disputed claim term). If a term is sufficiently structural on its

own, then it is not a means-plus-function term, but if it is not,

then § 112 ¶ 6 applies. Williamson, 792 F.3d at 1347-49.

If the court determines that § 112 ¶ 6 applies, it next

examines “whether the specification discloses sufficient structure

that corresponds to the claimed function.” Id. at 1351. The

“scope of coverage [is restricted] to only the structure,

materials, or acts described in the specification as corresponding

to the claimed function and equivalents thereof,” and the court

has a duty to construe the term to fit that limitation. Id. at

1347; see Verint Sys. Inc. v. Red Box Recorders Ltd., 166 F. Supp.

3d 364, 375 (S.D.N.Y. 2016) (“The ambiguity [provided for in § 112

¶ 6] comes at the cost of constraining the reach of the claim.”)

“The construction of a means-plus-function limitation follows

a two-step approach.” Omega Eng’g, Inc. v. Raytek Corp., 334 F.3d

1314, 1321 (Fed. Cir. 2003); see Rain Computing, Inc. v. Samsung

Elecs. Am., Inc., 989 F.3d 1002, 1007 (Fed. Cir. 2021). The first

step requires identifying the function, “staying true to the claim

language and the limitations expressly recited by the claims.”

Omega, 334 F.3d at 1322. The second step is “ascertain[ing] the

corresponding structures in the written description that perform

those functions.” Id. “Under this second step, structure

disclosed in the specification is corresponding structure only if

the specification or prosecution history clearly links or

associates that structure to the function recited in the claim.”

Sony Corp. v. Iancu, 924 F.3d 1235, 1239 (Fed. Cir. 2019) (citation

omitted). Put differently, the “focus of the ‘corresponding

structure’ inquiry is not merely whether a structure is capable of

performing the recited function, but rather whether the

corresponding structure is ‘clearly linked or associated with the

[recited] function.’” Cypress Lake Software, Inc. v. Samsung

Elecs. Am., Inc., 382 F. Supp. 3d 586, 599 (E.D. Tex. 2019)

(alteration in original) (quoting Medtronic, Inc. v. Advanced

Cardiovascular Sys., Inc., 248 F.3d 1303, 1311 (Fed. Cir. 2001)).

Under § 112 ¶ 6, however, “if a person of ordinary skill in

the art would be unable to recognize the structure in the

specification and associate it with the corresponding function in

the claim, a means-plus-function clause is indefinite.”

Williamson, 792 F.3d at 1352; see EON Corp. IP Holdings LLC v.

AT&T Mobility LLC, 785 F.3d 616, 621 (Fed. Cir. 2015) (means-plus-

function claim limitations must “satisfy the definiteness

requirement of § 112 ¶ 2”); In re Aoyama, 656 F.3d 1293, 1294,

1297-98 (Fed. Cir. 2011) (finding a means-plus-function software

patent claim was invalid as indefinite for failure to disclose the

corresponding algorithm performing that function); Default Proof

Credit Card Sys., Inc. v. Home Depot U.S.A., Inc., 412 F.3d 1291,

1302-03 (Fed. Cir. 2005) (invalidating a means-plus-function claim

for indefiniteness for lack of a structure in the specification

corresponding to the claimed function).

As with claim construction itself, the “determination that a

patent claim is invalid for failure to meet the definiteness

requirement” of § 112 ¶ 6 is “a legal conclusion that is drawn

from the court’s performance of its duty as the construer of patent

claims[.]” All Dental Prodx, LLC v. Advantage Dental Prod., Inc.,

309 F.3d 774, 778 (Fed. Cir. 2002) (alterations and citations

omitted); see Atmel Corp. v. Info. Storage Devices, Inc., 198 F.3d

1374, 1379 (Fed. Cir. 1999). As to the burden of proof, “[t]he

party alleging that the specification fails to disclose sufficient

corresponding structure must make that showing by clear and

convincing evidence.” TecSec, Inc. v. Int’l Bus. Machines Corp.,

731 F.3d 1336, 1349 (Fed. Cir. 2013); see Nature Simulation Sys.

Inc. v. Autodesk, Inc., 50 F.4th 1358, 1361 (Fed. Cir. 2022)

(“United States patents are accompanied by a presumption of

validity, 35 U.S.C. § 282, and invalidity must be established by

clear and convincing evidence.”); Dow Chem. Co. v. Nova Chemicals

Corp. (Canada), 809 F.3d 1223, 1227 (Fed. Cir. 2015) (Moore, J.,

concurring in the denial of rehearing en banc)

(“Precedent . . . requires that the burden of proving

indefiniteness remains on the party challenging validity and that

they must establish it by clear and convincing evidence.”).

Salem contends that two terms, “a control unit arranged to

control the blowing of pressurized air” and “a pressurization unit

for pressurizing the air sucked from inside the tempering furnace,”

are means-plus-function terms and are either invalid for

indefiniteness or substantially limited in scope by the operation

of § 112 ¶ 6. Plaintiffs maintain that both are sufficiently

structural terms rather than means-plus-function terms and propose

a valid construction for each. The court addresses the arguments

for each of these terms in turn below.

1. “a control unit arranged to control the blowing of

pressurized air”

Plaintiffs’ Construction Defendant’s Construction

“a controller to control air Indefinite

flow of pressurized air.”

(Doc. 32-2 at 12.) (Doc. 32-2 at 12.)

The parties dispute whether “a control unit arranged to

control the blowing of pressurized air” as it appears in Claim 2

of the ‘911 Patent is a means-plus-function term. Claim 2 of the

‘911 Patent reads in full:

2. An apparatus as claimed in claim 1, the apparatus

further comprising a control unit arranged to

control the blowing of pressurized air provided by

the compressor on the lower surface of the glass to

end before a heating cycle ends and such that the

blowing lasts maximally for 60% of an entire heating

cycle.

(‘911 Patent at Claim 2 (emphasis added).) Salem argues that this

term is means-plus-function: though the term does not recite the

word “means,” Salem contends it is nevertheless a means-plus-

function term because “control” is a functional descriptor that

modifies the nonce term “unit.” (Doc. 38 at 16-17 (citing Diebold

Nixdorf, Inc. v. Int’l Trade Comm’n, 899 F.3d 1291, 1298 (Fed.

Cir. 2018); Huawei Techs. Co. Ltd. v. T-Mobile US, Inc., No. 2:16-

CV-00056-JRG-RSP, 2017 WL 2267304, at *17-19 (E.D. Tex. May 24,

2017); Williamson, 792 F.3d at 1351).) Salem asserts that the

specification provides no additional structural details beyond

depicting the control unit as a “black box,” and it notes that

Plaintiffs have not pointed to any evidence, either intrinsic to

the patent or extrinsic, to suggest that the unit is structural in

nature. (Id. (citing ’540 Patent at 4:52-57, Fig. 1; Doc. 32-

3 ¶¶ 65, 67 (Fackelman testimony)).) Therefore, Salem argues, the

term should be interpreted as means-plus-function subject to the

limitations of § 112 ¶ 6.

Plaintiffs deny Salem’s contention and argue that the

presumption is in their favor here, noting that the term does not

recite the word “means” and that Salem has failed to meet its

burden to overcome it. Plaintiffs maintain that “control units or

controllers” are well-recognized structural units in patent law

that a POSA would understand, particularly by reference to the

depictions of how it interacts with other structures. (Doc. 40 at

16-17 (citing Doc. 40-5 at 139 (providing Mr. Bartoe’s testimony

that “[c]ontrol units or controllers were commonly used to ensure

that the glass tempering furnace was set to the correct temperature

for a particular glass tempering application” and would have been

obvious to a POSA)).) Plaintiffs also note that the term “control

unit” is further defined within the patent by reference to the

other components with which it interacts and how it relates to

other structural entities, particularly in Figure 1, citing case

law that reflects support for this reasoning. (Id. (citing ‘911

Patent at. Fig. 1 (showing a schematic diagram of how control unit

21 interacts with other components, particularly inverters 16 and

19, resistors 5 and 6, pressurization unit 10 and compressor 17);

United States Well Servs. v. Tops Well Servs., No. 3:19-CV-00237,

2020 WL 9439469, at *22-24 (S.D. Tx. Sept. 18, 2020) (finding that

“centralized control unit” is not subject to § 112 ¶ 6 where the

intrinsic evidence describes functions of and the structural

interactions between “other components” and the “centralized

control unit” includes a schematic of how the “centralized control

unit” interacts with other components)).) Thus, Plaintiffs argue,

the term is not means-plus-function in nature.

As an initial matter, Plaintiffs are correct that, in the

absence of the term “means” in the patent, Salem bears the burden

of showing that it is means-plus-function. Williamson, 792 F.3d

at 1348. Thus, while Salem argues that Plaintiffs have pointed to

no evidence supporting their reading of the claim term as non-

means-plus-function, it is Salem’s burden to show that the

presumption in Plaintiff’s favor is inapplicable.

The court finds on the evidence before it that Salem has not

made a sufficient showing to accomplish this. Though it cites

numerous cases with the term “control” as an adjective and “unit”

as a nonce term,16 the term “control unit” is made distinct in this

case, as Plaintiffs point out, by other reference to what it is,

what it does, and how it interacts with other parts of the patented

apparatus. Courts, including the Federal Circuit, have recognized

that relational language to corresponding components can render a

term sufficiently structural. Inventio AG, 649 F.3d at 1358-59;

Ultra-Mek, Inc. v. United Furniture Indus., Inc., No. 1:18CV281,

2019 WL 4723351, at *6 (M.D.N.C. Sept. 26, 2019); U.S. Well Servs.,

2020 WL 9439469. Here, the provided schematic of the control unit

shows it attaches and works with six other components of the glass

tempering invention, and the patent otherwise provides context in

the specification and history for how these pieces relate to one

another. (See, e.g., ‘911 Patent at 4:58-63.) Thus, the term

“control unit” is not unmoored from any structural implication, as

Salem suggests, but rather incorporates structure through its

interactions.

Moreover, Salem’s own representations to the court and the

16 For the proposition that “unit” is a nonce term, Salem relies

predominantly on Diebold Nixdorf, Inc., 899 F.3d at 1298; Huawei Techs.

Co. Ltd., 2017 WL 2267304 at *17-19; Dionex Softron GmbH, 811 F. App’x

at 632; and WSOU Investments LLC v. Google LLC, Nos. 2022-1066, 2022-

1067, 2023 WL 6210607 (W.D. Tex. Sept. 25, 2023). For the proposition

that adding the word “control” fails to impart any additional structure,

Salem looks to Williamson, 792 F.3d at 1351; IPS Group, Inc. v.

CivicSmart, Inc., No. 17-CV-632-CAB-(MDD), 2018 WL 6567843 (S.D. Cal.

Mar. 29, 2019); and Anderson Corp. v. Fiber Composites, LLC, 474 F.3d

1361 (Fed. Cir. 2007).

evidence it presents undermine its position that “control unit” is

a means-plus-function term because of a lack of structure. When

asked at oral argument how the term should have been phrased to be

sufficiently structural in Salem’s view, counsel noted that “the

patentee could have recited a more definite structure in the art,

such as a controller,” as “[a] controller is a known component in

the electrical engineering field.” (Doc. 89 at 62.) However, as

Plaintiffs point out, Salem’s own expert, Mr. Bartoe, in his

testimony presented “control units or controllers” as

interchangeable terms with identical meanings, both of which are

known and understood by a POSA in the field. (See id. at 70; Doc.

40-5 at 139.) While Salem notes that Mr. Fackelman disagreed with

Mr. Bartoe’s characterization of these two as interchangeable, Mr.

Fackelman’s testimony suffers all of the previously discussed

credibility problems along with a substantial new one raised by

Plaintiffs: his own patent uses the term “control unit” as a

meaningful term in the art. (See Doc. 40-11 at 107.) Therefore,

the court declines to find that Salem has met its burden of showing

this term is means-plus-function.

Salem conceded at oral argument that if the court held the

term was not means-plus-function, no additional inquiry into the

structure or definiteness of the term under § 112 ¶ 6 would be

required. (See Doc. 89 at 76-77.) Thus, having found the term is

not means-plus, the court declines to engage in the § 112 ¶ 6 two-

step inquiry. The court thereby adopts Plaintiffs’ proposed

construction. The term “a control unit arranged to control the

blowing of pressurized air,” as it appears in the ‘911 Patent,

Claim 2, will be interpreted to mean “a controller to control air

flow of pressurized air.” (Doc. 32-2 at 12.)

3. “a pressurization unit for pressurizing the air

sucked from inside the tempering furnace”

Plaintiffs’ Construction Defendant’s Construction

“a pressurizing unit that Governed by 112(6).

pressurizes air by applying Function: “pressurizing the

over pressure with respect to air sucked from inside the

the pressure of the furnace.” tempering furnace,”

Structure: turbochargers or

heat-endurance compressors.

(Doc. 32-2 at 9.) (Doc. 32-2 at 9.)

Finally, Salem challenges “a pressurization unit for

pressurizing the air sucked from inside the tempering furnace,” as

it appears in Claim 1 of the ‘911 Patent, which reads in full:

1. An apparatus for heating glass, the apparatus

comprising a tempering furnace comprising horizontal

rolls arranged to carry the glass and to form a

conveyor thereof, an upper side return pipe for

sucking air from inside the tempering furnace, a

pressurization unit for pressurizing the air sucked

from inside the tempering furnace, means for blowing

the pressurized air back to an upper surface of the

glass, a compressor for pressurizing air taken from

outside the furnace, a pipe system for conveying the

air pressurized by the compressor to a lower surface

of the glass, and means for heating the air

pressurized by the compressor.

(‘911 Patent at Claim 1 (emphasis added).)

The argument and analysis for whether “a pressurization unit

for pressurizing the air sucked from inside the tempering furnace,”

as it appears in Claim 1 of the ‘911 Patent is largely duplicative

of that for the preceding “control unit” term, which the parties

acknowledge. (Doc. 89 at 78.) Plaintiffs again assert that the

presumption lies in their favor, given that the term does not use

the word “means” and that the term “pressurization unit” is a well-

understood structural term that implicates a category of devices

in the art such that it avoids § 112 ¶ 6. (See Doc. 40 at 24-26.)

Salem maintains that despite not using the word “means,” the term

is subject to § 112 ¶ 6 because “pressurization unit” is another

“nonce” term with a functional adjective that is not sufficiently

defined by its structure in the art and is instead defined by its

functional operations. (Doc. 38 at 23-24.) Parties did not

address this issue at oral argument, instead opting to rest on

their briefs. (Doc. 89 at 78.)

As with the prior terms, Salem has not overcome the

presumption that this term is not means-plus function. Because

the parties in their briefs to some extent conflate the first stage

of the analysis, determining whether the term is a means-plus-

function term because it is not structural on its own, with the

second stage of the analysis, determining whether the term is

indefinite for failing to provide a sufficient structural

limitation, it is unclear what evidence each offers on the first

issue. However, because the presumption falls in Plaintiffs’

favor, this deficiency primarily undermines Salem’s arguments.

The only evidence that Salem expressly cites as indicating that a

“pressurization unit” is not a term of art in the field of

tempering glass or sufficiently structural on its own is the

testimony of Mr. Fackelman, which the court has already

discredited. (See Doc. 38 at 24 (citing Doc. 32-3 ¶ 91).) At a

minimum, Plaintiffs have pointed to the testimony of Salem’s other

expert, Mr. Bartoe, suggesting that a POSA would understand the

term (Doc. 40-5 at 40-43, 123-24) and several instances in the

specification (‘911 Patent at 3:57-58, 3:66-4:4, 3:54-62) that

tend to suggest a “pressurization unit” would be understood as a

defined class of structural components within the state of the

art. Salem has not provided the court with credible testimony to

refute either this evidence or the general presumption in

Plaintiffs’ favor.

As a result, this court finds that the term “a pressurization

unit for pressurizing the air sucked from inside the tempering

furnace” is not a means-plus-function term. Thus, it is not

limited by the requirements of § 112 ¶ 6, and the court need not

engage in that analysis. Plaintiffs’ proposed construction

prevails. The term “a pressurization unit for pressurizing the

air sucked from inside the tempering furnace,” as it appears in

Claim 1 of the ‘911 Patent, will be construed to mean “a

pressurizing unit that pressurizes air by applying over pressure

with respect to the pressure of the furnace.” (Doc. 32-2 at 9.)

III. CONCLUSION

For the reasons stated, the court finds that Plaintiffs’

arguments prevail in all instances, and each of their proposed

constructions is adopted.

IT IS THEREFORE ORDERED that the disputed claim terms be

construed as follows:

•

“sucking [hot] air from inside the [tempering]

furnace,” as recited in the ‘540 Patent, Claim 1, and

in the ‘911 Patent, Claim 1, will be construed to mean

“creating a pressure differential to pull air at

elevated temperature from inside the furnace.”

•

“the improvements consisting essentially of,” as

recited in the ‘540 Patent, Claim 1, will be construed

to include components or steps not listed in the claim

so long as they do not materially alter the “heating”

and “blowing” properties listed.

•

“controlled in a forced manner so as to heat at a

power level in accordance with a heating profile,” as

recited in the ‘540 Patent, Claims 3, 12, 13, and 14,

will be construed to mean “controlled to heat at a

power level in accordance with a heating profile.”

•

“heat, using forced control, at a power level in

accordance with a heating profile,” as recited in the

‘911 Patent, Claim 4, will be construed to mean “heat

at a power level in accordance with a heating

profile.”

•

“the temperature of the glass follows a predetermined

heating curve,” as recited in the ‘540 Patent, Claims

3, 12, 13, and 14, will be construed to mean “the

temperature of the glass follows a heating curve

determined beforehand.”

•

“from a starting moment of the heating,” as recited

in the ‘540 Patent, Claim 8, will be construed to mean

“when heating of the glass begins.”

•

“a control unit arranged to control the blowing of

pressurized air,” as recited in the ‘911 Patent, Claim

2, will be construed to mean “a controller to control

air flow of pressurized air.”

•

“a pressurization unit for pressurizing the air sucked

from inside the tempering furnace,” as recited in the

‘911 Patent, Claim 1, will be construed to mean “a

pressurizing unit that pressurizes air by applying

over pressure with respect to the pressure of the

furnace.”

/s/ Thomas D. Schroeder

United States District Judge

April 18, 2024