1

The parties had initially submitted a series of back-andforth briefing, including a number of replies and sur-replies,

all of which was stricken by the court when each side was ordered

to submit a single brief setting forth all of its claim

construction arguments.

UNITED STATES DISTRICT COURT

DISTRICT OF NEW HAMPSHIRE

Best Management Products, Inc.

v. Civil No. 07-151-JL

 Opinion No. 2008 DNH 099

New England Fiberglass, L.L.C.

and Mark Richardson

O R D E R

The plaintiff, Best Management Products, Inc. (“BMP”)

alleges that the defendants, New England Fiberglass and Mark

Richardson, its president and sole owner, (collectively, “NEF”),

are infringing BMP’s patent for an oil and debris separator to be

installed in a catch basin, United States Patent No. 6,126,817

(filed Oct. 3, 2000). The parties differ over the meaning of the

phrase “a vent mounted on the wall of said hood and extending

upwardly therefrom” as it appears in independent claims 1, 5-6,

10, and 15 of the patent. The court received briefing and

conducted a hearing on this issue in accordance with Markman v.

Westview Instruments, Inc., 517 U.S. 370, 388 (1996).1

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 1 of 27
2

In construing a patent, this court’s “task is not to decide

which of the adversaries is correct” in its proffered

interpretation, but to fulfill the court’s “independent

obligation to determine the meaning of the claims,

notwithstanding the views asserted by the adversary parties.” 

Exxon Chem. Patents, Inc. v. Lubrizol Corp., 64 F.3d 1553, 1555-

56 (Fed. Cir. 1995).

3

These principles were discussed with reference to nearly

the same authorities in this court’s claim construction order in

Velcro Indus. B.V. v. Taiwan Paiho Ltd., 2005 DNH 035, 1-3. 

Because the parties agree that these principles are controlling,

what follows is an essentially verbatim quotation from that

order.

2

This court has jurisdiction over this matter under 28 U.S.C.

§§ 1331 (federal question) and 1338(a) (2006) (patents). For the

foregoing reasons, the court adopts--with some deletions and

modifications--NEF’s proffered interpretation of the disputed

phrase, construing it to mean:

a separate hollow fitting affixed to the wall of said

hood, said fitting having a lower end communicating with

a hole in the wall of the outlet hood and an upper end

extending upwardly from said hood to a position above

said hood.2

I. APPLICABLE LEGAL STANDARD3

“It is a bedrock principle of patent law that the claims of

a patent define the invention to which the patentee is entitled

the right to exclude.” Innova/Pure Water, Inc. v. Safari Water

Filtration Sys., 381 F.3d 1111, 1115 (Fed. Cir. 2004). The

meaning of language in a patent claim presents a question of law

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 2 of 27
3

for the court to decide. Markman, 517 U.S. at 388. In the

absence of an express intent to impart a novel meaning to the

claim terms, the words take on the full breadth of the ordinary

and customary meanings attributed to them by those of ordinary

skill in the art. See, e.g., Metabolite Labs., Inc. v. Lab.

Corp. of Am. Holdings, 370 F.3d 1354, 1360 (Fed. Cir. 2004),

cert. denied, 126 S. Ct. 2976 (2006); Tate Access Floors, Inc. v.

Interface Architectural Res., Inc., 279 F.3d 1357, 1370 (Fed.

Cir. 2002).

To ascertain this meaning, the court must first examine the

intrinsic evidence, which includes the claims themselves, the

specifications, and any prosecution history submitted by the

litigants. E.g., Goldenberg v. Cytogen, Inc., 373 F.3d 1158,

1164 (Fed. Cir. 2004) (citing Vitronics Corp. v. Conceptronic,

Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). The court starts

with the actual language of the claim. E.g., Int’l Rectifier

Corp. v. IXYS Corp., 361 F.3d 1363, 1370 (Fed. Cir. 2004); 3M

Innovative Props. Co. v. Avery Dennison Corp., 350 F.3d 1365,

1370 (Fed. Cir. 2003). “If the claim language is clear on its

face, then [the] consideration of the rest of the intrinsic

evidence is restricted to determining if a deviation from the

clear language of the claims is specified.” Interactive Gift

Express, Inc. v. Compuserve Inc., 256 F.3d 1323, 1331 (Fed. Cir.

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 3 of 27
4

2001); see also Int’l Rectifier, 361 F.3d at 1370; Anchor Wall

Sys., Inc. v. Rockwood Retaining Walls, Inc., 340 F.3d 1298,

1306-1307 (Fed. Cir. 2003).

Although the court must therefore construe the claims in

light of the specifications, it must take care not to read

limitations from the specifications into the claims. Innova/Pure

Water, 381 F.3d at 1117; Liebel-Flarsheim Co. v. Medrad, Inc.,

358 F.3d 898, 904 (Fed. Cir. 2004). “If the meaning of the claim

limitations is apparent from the totality of the intrinsic

evidence, then the claim has been construed.” Interactive Gift,

256 F.3d at 1332. If, and only if, a “genuine ambiguity” still

persists, the court may turn to extrinsic evidence, such as

expert testimony, to interpret the claim. Intel Corp. v. VIA

Techs., Inc., 319 F.3d 1357, 1367 (Fed. Cir. 2003) (citing

Vitronics, 90 F.3d at 1582); see also, e.g., Sunrace Roots Enter.

Co. v. SRAM Corp., 336 F.3d 1298, 1307 (Fed. Cir. 2003).

II. BACKGROUND

BMP holds an assignment of the patent-in-suit from its

inventors, Lee A. Duran and Thomas J. Mullen III; Mullen, one of

BMP’s principals, accompanied its counsel at the Markman hearing. 

The patent discloses “a trap which is installed in . . . catch

basins, storm drains and the like and which traps floatable

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 4 of 27
5

debris and liquids of specific gravities that are different from

that of water,” particularly oil. ’817 patent, col.1, l.10-14. 

While existing technology had achieved this effect through “a

complicated structure including a plurality of separating

partitions,” the patented invention employs “a separating

structure that is relatively easy to install into a existing

catch basin while enabling maintenance of the outlet pipe through

which filtered water is discharged.” Id., col.2, l.5-17.

The invention contemplates a hood which “is sealably mounted

to the basin wall around its outlet and extends downwardly below

it to prevent materials such as oil and floatable debris from

being drawn downstream into the outlet.” Id., col.2, l.63-66. 

Of crucial relevance to the dispute between the parties, “[a]n

anti-siphon vent extends up from the hood . . . to equalize air

pressure between the compartment enclosed by the hood and ambient

air above the basin.” Id., col.3, l.1-3. As Mullen explained at

the Markman hearing, this vent thus serves to prevent materials

floating inside the basin above the bottom of the hood from

nevertheless being sucked underneath it as the water in the basin

seeks its own level by filling the airspace inside the hood.

So the patent claims, in relevant part:

a hood extending along an axis, and having a wall

shaped to partially sealingly fit around the outlet of

an interior wall of the waste water basin so as to

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 5 of 27
4

The other disputed claims (5-6, 10, and 15) contain the

same language quoted in the second indented paragraph of claim 1,

i.e., col.7, l.41-47, except that claims 5-6 and 10 omit the

phrase “to inhibit siphoning of [the] water mixture from inside

said waste water basin through said compartment into said

outlet,” while claim 15 replaces that phrase with “so as to

inhibit siphoning action from said outlet causing a drawing of

waste water from the basin,” col.10, l.20-23. Aside from BMP’s

claim differentiation argument, discussed infra, the parties do

not attribute any significance to these differences in construing

the phrase at issue, which appears in each of the disputed

claims. So the court will not refer to these other disputed

claims further, citing to the language of claim 1 only.

6

define at least a partially sealable compartment

therewith . . . [and]

a vent mounted on the wall of said hood and extending

upwardly therefrom, the vent opening into the

compartment to provide air communication with the

compartment upon mounting of the hood to the interior

wall of the waste water basin to inhibit siphoning of

[the] water mixture from inside said waste water basin

through said compartment into said outlet.

Id., col.7, l.34-47 [claim 1].4

BMP claims that NEF is infringing on the patent by marketing

its own hooded outlet covers; NEF denies this and has

counterclaimed, asserting that its products do not infringe, that

the patent is invalid, and that BMP has maintained this suit as

an illegal attempt at a monopoly in violation of New Hampshire’s

Consumer Protection Act, N.H. Rev. Stat. Ann. § 358-A. NEF

contends that the disputed claim language--“a vent mounted on the

wall of said hood and extending upwardly therefrom”--requires a

“separate, hollow fitting affixed, set or supported on the wall

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 6 of 27
5

Though the relationship between the claims and the

allegedly infringing products has no relevance to the claim

construction inquiry itself, a court cannot legitimately exercise

its judicial power to undertake the inquiry without an actual

controversy as to whether the claims cover the products. See

Vivid Techs., Inc. v. Am. Science & Eng’g, Inc., 200 F.3d 795,

803 (Fed. Cir. 1999) (“although the claims are construed

objectively and without reference to the accused device, only

those terms need be construed that are in controversy, and only

to the extent necessary to resolve the controversy”). Of course,

the court expresses no view on the issues of infringement or

validity at this stage.

7

of the outlet hood, . . . having a lower end communicating with a

hole in the outlet hood and an upper end extended upwardly from

the wall to a position above the wall . . . so that the upper end

terminates above flood level.” Under this construction, NEF

argues, its products do not infringe, because they achieve antisiphon venting through the use of a hole in the hood, rather than

the “separate fitting” NEF claims is required by the patent.5

III. ANALYSIS

Neither party asserts that the patent expresses an intent to

impart a novel meaning to the phrase “a vent mounted on the wall

of said hood and extending upwardly therefrom” or that the phrase

lacks clarity. Instead, each contends that the language of the

claims and other intrinsic evidence supports its construction. 

NEF, as just noted, construes the phrase as a “separate, hollow

fitting affixed, set or supported on the wall of the outlet hood,

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 7 of 27
8

the hollow fitting having a lower end communicating with a hole

in the outlet hood and an upper end extended upwardly from the

wall to a position above the wall of the outlet hood so that the

upper end terminates above flood level,” while BMP construes it

as “an opening positioned on the hood wall that provides air

communication between the lower interior hood compartment and the

upper ambient air when the hood is installed.”

“Claim construction begins with the language of the claims.” 

Research Plastics, Inc. v. Fed. Packaging Corp., 421 F.3d 1290,

1295 (Fed. Cir. 2005). Although the court has little doubt that

the word “vent,” taken in isolation, could mean simply “opening”

as BMP suggests, the remainder of the claim language contradicts

this construction. “While certain terms may be at the center of

the claim construction debate, the context of the surrounding

words of the claim also must be considered in determining the

ordinary and customary meaning of those terms.” ACTV, Inc. v.

Walt Disney Co., 346 F.3d 1082, 1088 (Fed. Cir. 2003). The

phrase “a vent mounted on the wall of said hood and extending

upwardly therefrom” contains three qualifiers which, in the

court’s view, make clear that “vent” is not synonymous with

“opening” as BMP suggests: “mounted,” “extending upwardly,” and

“therefrom.”

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 8 of 27
6

The claim likewise refers to the invention as “[a]n

apparatus for mounting around an outlet of a waste water basin,”

’817 patent, col.7, l.28-29, and containing “a mounting flange

located to at least partially surround the compartment around the

outlet,” id., col.7, l.48-49.

9

First, the court disagrees with BMP that the ordinary

meaning of “mounted” encompasses the “positioning” of an opening

in a structure. One does not commonly speak of “mounting” an

opening in a wall, but, as NEF argues, of “making,” “cutting,”

“punching,” or “inserting” it. See Asyst Techs., Inc. v. Emtrak,

Inc., 402 F.3d 1188, 1193 (Fed. Cir. 2005) (applying “ordinary

meaning of ‘mounted on,’ i.e., securely attached, affixed, or

fastened to”); Kinzenbaw v. Case, LLC, 318 F. Supp. 2d 778, 793

(N.D. Iowa 2004) (construing “mounting” in patent claim “to have

its plain meaning which is ‘to fix securely to a support’”),

aff’d, 179 Fed. Appx. 20 (Fed. Cir. 2006) (unpublished

disposition). The interpretation of “mounted” as “affixed,” as

NEF suggests, finds further support in the use of the verb in the

phrase “mounting of the hood to the interior wall of the

wastewater basin” in the very same claim. ’817 patent, col.7,

l.44-45.6 Just “positioning” the hood on the wall of the basin,

rather than “affixing” it there, would not “define at least a

partially sealable compartment” as the claim requires. ’817

patent, col.7, l.36-37. Because “[a] word or phrase used

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 9 of 27
10

consistently throughout a claim should be interpreted

consistently,” Phonometrics, Inc. v. N. Telecom, Inc., 133 F.3d

1459, 1465 (Fed. Cir. 1998), “mount” cannot mean simply

“position” when used in reference to the vent when the verb

necessarily means “affix” when used in reference to the hood. 

See Asyst Techs., 402 F.3d at 1193-94 (construing “mounted on” in

patent claim to mean “affixed to” where “[t]he specification uses

the phrase ‘mounted on’ to refer to a number of other components,

and the context makes clear that the phrase is used in those

instances to mean securely affixed to objects”). 

The court also disagrees with BMP’s argument at the Markman

hearing that “mounted” is synonymous with “positioned” in a more

general sense--though, as just noted, it is the specific usage of

a term in the patent, rather than in unrelated contexts, that

determines its proper construction. In any event, “mounted” is

narrower than “positioned” in that “mounting” denotes the

placement of one object in a contiguous spatial relationship with

another object, while “positioning” can mean simply the placement

of any single object in space, without reference to another

object. The court agrees with NEF, then, that the use of the

term “mounted” to describe the “vent” requires the vent to

consist of an object “separate” from the hood wall.

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 10 of 27
11

Second, the court disagrees with BMP that an “opening” can

“extend” as that word is commonly understood, i.e., to reach from

one point to another. Cf. Intamin, Ltd. v. Magnetar Techs.,

Corp., 483 F.3d 1328, 1336 (Fed. Cir. 2007) (upholding

construction of “length” in phrase “extend the length of” as

“extent from end to end” because, inter alia, “[t]he verb

‘extend’ already suggests that the ‘length’ reaches from one end

to another”); Kinzenbaw, 318 F. Supp.2d at 793 (“‘extend’ means

‘to stretch out in distance, space, or time’”). This is

particularly true when the claim uses “extending” in conjunction

with the modifier “upwardly,” indicating not only a distance

between two points, but in a particular direction. Cf. FlexRest, LLC v. Steelcase, Inc., 455 F.3d 1351, 1362 (Fed. Cir.

2006) (construing “extend” as it appeared in claim to mean

“extend upwardly”).

As with its proffered construction of “mounted” to mean

simply “positioned,” BMP argues that “extend” refers “simply to

the positioning of the vent on the hood,” but, just as “position”

has a broader meaning than “mount,” that verb also has a broader

meaning than “extend,” which, again, requires its object to cover

a distance between two points. Also as in the case of “mounted,”

this conclusion finds further support in the use of “extending”

elsewhere in the claim to refer to “a hood extending along an

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 11 of 27
12

axis,” ’817 patent, col.7, l.34, as well as language elsewhere in

the patent using “extend” in the same sense. See id., col.1,

l.56-57 (describing feature of prior art as “[a]n outlet fitting

[that] extends upward”); id., col.2, l.63-65 (describing feature

of invention as “hood [that] is sealably mounted to the basin

wall around its outlet and extends downwardly below it”), id.,

col.4, l.9-11 (describing feature of embodiment as flange with

“bottom segment that extends laterally and horizontally from the

body”). 

Taking the word “extending” to signify only that the vent is

positioned in the hood wall would also essentially read the word

out of the claim, because the phrase “mounted on the wall of said

hood” already specifies the location of the vent vis-a-vis the

hood wall. It is, of course, a fundamental tenet of claim

construction that “claims are interpreted with an eye toward

giving effect to all terms in the claim.” Bicon, Inc. v.

Straumann Co., 441 F.3d 945, 950 (Fed. Cir. 2006). BMP maintains

that its proffered construction does not offend this principle

because, unlike “mounted,” the term “extending” specifies that

the vent “is positioned to provide air communication between the

lower interior hood compartment and the upper ambient air when

the hood is installed in the catch basin.” But this argument

simply makes “extending” superfluous in light of other language

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 12 of 27
13

in the claim that itself describes the vent as “opening into the

compartment to provide air communication with the compartment

upon mounting of the hood to the interior wall of the waste water

basin.” ’817 patent, col.7, l.42-44. In addition, because it is

the hood wall that defines a partially sealable compartment

within the waste water basin, any vent in that wall will

necessarily provide communication with the ambient air in the

basin, which completely surrounds the wall; in light of this

reality, “extending” must signify something more than just the

“positioning” of the vent in relation to the wall.

Third, the claim describes the vent as “extending upwardly

therefrom”--i.e., from “the wall of said hood”--further

indicating that the vent reaches from the wall to some point

beyond it, rather than consisting merely of an opening in the

wall. BMP disputed this conclusion at the Markman hearing,

arguing that the phrase referred to an opening “extending

upwardly” from the inside wall of the hood to the outside wall of

the hood. Based on the principle that a pronoun refers to its

nearest antecedent noun, however, the “there” in “therefrom”

refers to the “hood,” not to its “wall.” See In re Hyatt, 708

F.2d 712, 714 (Fed. Cir. 1983) (“A claim must be read in

accordance with the precepts of English grammar.”).

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 13 of 27
7

In NEF’s proffered construction, the upper end extends

upwardly from the wall, rather than the hood, but this

construction is inconsistent with the claim and the specification

for the reasons just discussed.

14

And, grammatical technicalities aside, one would expect the

disputed phrase to refer specifically to the hood’s inside wall

if BMP’s construction were correct--just as the claim refers

specifically to “the interior wall of the waste water basin” as

the place for the “mounting of the hood” itself. ’817 patent,

col.7, l.44-45. Indeed, the specification teaches that “[a]n

anti-siphon vent mounted to the hood extends upwardly therefrom,”

id., col.2, l.27-28 (emphasis added), removing even the slightest

doubt that the vent extends upwardly from the hood, rather than

from its interior wall. The court agrees in substance with NEF

that “extending upwardly therefrom” requires the vent to have “a

lower end communicating with a hole in the wall of the outlet

hood and an upper end extending upwardly from said hood to a

position above said hood.”7

“In some cases, the ordinary meaning of claim language as

understood by a person of skill in the art may be readily

apparent even to lay judges, and claim construction in such cases

involves little more than the application of the widely accepted

meaning of commonly understood words.” Phillips v. AWH Corp.,

415 F.3d 1303, 1314 (Fed. Cir. 2005) (en banc). Because the

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 14 of 27
15

words at issue--“vent,” “mounted,” and “extending upwardly

therefrom”--are “commonly understood,” and the parties agree that

those words as used in the claim simply have their “widely

accepted meaning,” this appears to be such a case. Accordingly,

the court need consider the remaining intrinsic evidence for the

sole purpose of “determining if a deviation from the clear

language of the claims is specified.” Interactive Gift, 256 F.3d

at 1331; accord Phillips, 415 F.3d at 1316-17 (observing that

“the specification may reveal a special definition given to a

claim term by the patentee that differs from the meaning it would

otherwise possess” or “an intentional disclaimer, or disavowal,

of claim scope by the inventor”).

The parties point to nothing in the specification that would

justify a departure from the clear language at issue here. And

BMP cites to only three passages from the specification in

support of its proffered construction. First, based on

statements describing the “object of the present invention” as

“to provide a means for equalizing pressure between a catch basin

and its outlet pipe” and “to provide a discharge path for gases,”

’817 patent, col.2, l.48-54, BMP argues that one skilled in the

art would “understand that the primary purpose of the vent is to

provide air communication,” which could be achieved by a simple

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 15 of 27
8

The court notes at the outset that these statements

describe the object of the invention as a whole, rather than the

“vent” required by the claims, and therefore shed little light on

the elements of the vent set forth in the claims. 

16

hole in the hood wall.8 BMP makes a similar argument based on

the teaching in the specification that “[t]he anti-siphon vent is

sized to equalize air pressure between the compartment enclosed

by the hood and ambient air above the basin.” Id., col.3, l.1-3.

When a claim discloses a particular structure, however, its

literal scope is limited to that structure, and does not extend

to different structures that happen to have the same “purpose.” 

See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d

558, 589 (Fed. Cir. 2000) (“language reciting . . . structure

narrows the literal scope of the claim”), rev’d on other grounds,

535 U.S. 722 (2002); Wright Med. Tech., Inc. v. Osteonics Corp.,

122 F.3d 1440, 1443 (Fed. Cir. 1997) (disagreeing with

construction of term to include every structure “that meets the

functional objective of the invention”); Envtl. Instruments, Inc.

v. Sutron Corp., 877 F.2d 1561, 1564 (Fed. Cir. 1989) (rejecting

argument to extend the literal scope of a claim beyond its

language to the patent’s “teachings”). Whatever the

specification might disclose to a skilled artisan about the

“purpose” of the vent described in the claims, that teaching

cannot broaden their literal language without ignoring the

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 16 of 27
9

Furthermore, as emphasized by NEF in its briefing and at

the Markman hearing, other parts of the specification appear to

use the terms interchangably. See ’817 patent, col.4. l.32-34

(referring to same structure in figs. 1-4 as both “vent” and

“vent pipe”); id., col.7, l.3-8 (referring to same structure in

fig. 12 as both “vent pipe” and “vent”). 

17

“bedrock principle of patent law that the claims of a patent

define the invention to which the patentee is entitled the right

to exclude.” Innova/Pure Water, Inc., 381 F.3d at 1115.

BMP also argues that, because the specification

distinguishes between the terms “vent” and “vent pipe” in two

places, “vent” cannot refer only to a structure comprised of a

“pipe” in the manner NEF suggests. But NEF does not propose to

limit the scope of “vent” to a “pipe,” but to a “separate hollow

fitting”--a limitation that is consistent with the parts of the

specification describing the “vent” as a “vent pipe,” which is

simply one example of a “separate hollow fitting.”9 Indeed, the

written description specifically contemplates that such a fitting

may form part of the vent, teaching that “[t]he vent can be open,

but preferably is terminated either with a filter . . . or a with

a flapper valve . . . . Other fittings adapted to control the

flow of air and to prevent the entrance of water can be used.” 

’817 patent, col.4, l.35-40 (references to figure omitted). 

As this passage indicates, the embodiments disclosed in the

parts of the specification relied on by BMP actually support

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 17 of 27
18

NEF’s reading of the disputed claim language. One of those

embodiments teaches that the “[v]ent can be formed of a PVC vent

pipe and mounted to the upper part of the wall . . . . [A]n

upper end of vent pipe is provided with a 90E elbow.” ’817

patent, col.4, l.32-35 (emphases added; references to figure

omitted). The other describes “a pressure-equalization vent

having a vent pipe whose end segment is bent back.” Id., col.6,

l.53-54 (emphasis added; references to figure omitted). 

Consistent with the claim language “a vent mounted on the wall of

said hood and extending upwardly therefrom,” these embodiments

thus disclose an independent structure affixed to the hood wall

and having an “end,” rather than merely an “opening” in the hood

wall. The same is true of the other disclosed embodiments, which

describe the vent as “sufficiently long so that its upper end

terminates above flood level,” id., col.5, l.64-65, and refer to

“a float valve assembly . . . mounted to a flange at the end of

[the] vent pipe,” id., col.7, l.9-11. Indeed, in discussing this

particular embodiment, the patent explains that, while “[t]he

vent pipe is made sufficiently long so that its end segment is

above static level and a liquid normally cannot enter the vent

pipe,” the float valve serves to prevent this from happening even

when “as a result of heavy rains, the incoming mixture may reach

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 18 of 27
19

a flood level” in the catch basin higher than the “static level.” 

Id., col.6, l.57-65 (references to figure omitted).

BMP argues that relying on these embodiments to limit the

scope of “vent” flies in the face of the well-settled rule

against reading limitations from the embodiments into the claims. 

Innova/Pure Water, 381 F.3d at 1117. As the Federal Circuit has

explained, however, “claims ‘must be read in view of the

specification, of which they are a part.’” Phillips, 415 F.3d at

1315 (quoting Markman v. Westview Instruments, Inc., 52 F.3d 967,

978 (Fed. Cir. 1995), aff’d, 517 U.S. 370 (1996)). So,

“[a]lthough claims need not be limited to the preferred

embodiment when the invention is more broadly described, neither

do the claims enlarge what is patented beyond what the inventor

has described as the invention.” Inpro II Licensing, S.A.R.L. v.

T-Mobile USA, Inc., 450 F.3d 1350, 1355 (Fed. Cir. 2006)

(internal quotation marks omitted). As discussed supra, the

clear language of the claims does not allow “vent” to be

construed as “opening”; the description of the embodiments simply

confirms this conclusion. “The construction that stays true to

the claim language and most naturally aligns with the patent’s

description of the invention will be, in the end, the correct

construction.” Renishaw PLC v. Marposs Societa’ per Azioni, 158

F.3d 1243, 1250 (Fed. Cir. 1998).

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 19 of 27
20

Accordingly, the court cannot adopt BMP’s proffered

construction of “a vent mounted on the wall of said hood and

extending upwardly therefrom” to mean “an opening positioned on

the hood wall that provides air communication between the lower

interior hood compartment and the upper ambient air when the hood

is installed.” As NEF persuasively argues, this construction

reads all of the limitations on “vent” out of the disputed phrase

because, as noted supra, the balance of the claim teaches--in

language virtually identical to that proposed by BMP--that the

vent “open[s] into the compartment to provide air communication

with the compartment.” ’817 patent, col.7, l.42-44. BMP’s

reading, then, ignores the basic premise of patent law that

“[e]ach element contained in a patent claim is deemed material to

defining the scope of the patented invention.” Warner-Jenkinson

Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 29 (1997). 

While the court believes that NEF’s proffered construction

is more faithful to the language of the claims and

specifications, the court nevertheless declines to adopt that

construction in its entirety. NEF argues that the disputed

phrase means “a separate, hollow fitting affixed, set or

supported on the wall of the outlet hood, the hollow fitting

having a lower end communicating with a hole in the outlet hood

and an upper end extended upwardly from the wall to a position

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 20 of 27
21

above the wall of the outlet hood so that the upper end

terminates above flood level.” Though “in clarifying the meaning

of claim terms, courts are free to use words that do not appear

in the claim so long as the resulting claim interpretation

accords with the words chosen by the patentee to stake out the

boundary of the claimed property,” Pause Tech. LLC v. TiVo,

Inc., 419 F.3d 1326, 1333 (Fed. Cir. 2005) (internal bracketing,

ellipse, and quotation marks omitted), a court cannot read

limitations into a claim any more than it can read them out. 

See, e.g., Innova/Pure Water, 381 F.3d at 1117 (quoting McCarty

v. Lehigh Valley R. Co., 160 U.S. 110, 116 (1895)). 

The court believes that NEF’s proposed construction contains

a limitation unsupported in the claim language or elsewhere in

the intrinsic evidence, namely, “so that the upper end terminates

above flood level.” NEF finds its sole support for this phrase

in the embodiments, discussed supra, containing a float valve

assembly to prevent the liquid in the catch basin from leaking

into the vent when the liquid reaches a “flood level” exceeding

the length of the vent pipe. The other disclosed embodiments of

the invention, however, do not include the float valve assembly;

in those embodiments, “[t]he vent pipe is made sufficiently long

so that its end segment is above the static level and a liquid

normally cannot enter the vent pipe.” ’817 patent, col.6, l.57-

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 21 of 27
10The court also declines to construe mounted as “affixed,

set or supported” in the manner NEF suggests. In this context,

“set” and “supported” are merely synonyms of “affixed,” and

therefore lend no additional content to the construction of the

disputed phrase; courts must guard against this kind of “overconstruction” of patent claims. “An overly precise or specific

interpretation of claim language, especially language with a

plain meaning, may be deemed excessive in that it invades the

province of the trier of fact.” 5A Donald A. Chisum, Chisum on

Patents § 18.03[1][b], at 18-93--18-94 (2001 & supp. 2006)

(footnote omitted). 

22

60 (emphasis added; references to figure omitted). The patent

further explains that “[u]nder normal conditions . . . [this]

static level coincid[es] with respective lower segments” of the

inlet and outlet pipes of the catch basin “but above the bottom

edge where the intake to [the] compartment of [the] hood begins.” 

Id., col.5. l.18-21 (references to figures omitted). Because the

patent clearly discloses embodiments in which the vent terminates

above this static level, rather than above flood level, the court

cannot read the limitation “so that the upper end terminates

above flood level” into the claims.10 See, e.g., Innova/Pure

Water, 381 F.3d at 1117.

The court also disagrees with NEF that BMP is estopped from

seeking its proffered construction of “a vent mounted on the wall

of said hood and extending upwardly therefrom” by the prosecution

history of the ’817 patent. NEF argues that, after the examiner

rejected what are now claims 5 and 6, the patentees amended them

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 22 of 27
11Claim 1 was initially rejected as unpatentable because the

examiner believed that prior patents had made the proposed

invention obvious. Though the patentees eventually overcame this

rejection, they did not do so by adding the disputed limitation,

which, again, was contained in claim 1 as originally submitted.

23

to include the disputed limitation, giving rise to the inference

that the limitation was necessary for patentability. See

generally Warner-Jenkinson, 520 U.S. at 33. But, as BMP points

out, those claims--which were eventually allowed as independent

claims--had been submitted as claims dependent on claim 1, which

in its original form contained the limitation “a vent mounted on

the hood of said wall and extending upwardly therefrom.” Letter

from Louis H. Reens & Yuri Kateshov to Ass’t Comm’r for Patents,

at 2 (Mar. 20, 2000). And the examiner had not rejected what are

now claims 5 and 6, but simply objected to them as “dependent

upon a rejected base claim,” explaining that they “would be

allowable if rewritten in independent form including all of the

limitations of the base claim,” Official Action, USPTO, at 5

(Dec. 22, 1999)--which, as just noted, already contained the

limitation at issue.11 By rewriting the dependent claims at

issue to include this limitation, then, the patentees did not

narrow them to avoid prior art in a manner giving rise to

prosecution history estoppel. See Festo, 535 U.S. at 737. So

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 23 of 27
12The court considers the prosecution history relevant to the

language at issue only insofar as it reveals yet another example

of the patentees speaking of the vent as a “vent pipe.” In

describing the invention generally--i.e., not in reference to any

particular claim or embodiment--the patentees stated, “A vent

pipe is provided on the hood so that the compartment formed

between the hood and the wall of the basin is maintained at

outside air pressure. This inhibits the siphoning of liquid.” 

Letter from Reems & Kateshov, supra, at 9-10. “Statements that

describe the invention as a whole, rather than statements that

describe only preferred embodiments, are more likely to support a

limiting definition of a claim term.” C.R. Bard, Inc. v. U.S.

Surgical Corp., 388 F.3d 858, 864 (Fed. Cir. 2004).

24

the court has not relied on that doctrine in adopting in part

NEF’s proffered construction of the disputed phrase.12 

Finally, BMP argues that, because claim 7 discloses the

apparatus “as defined in claim 6 wherein the vent is a pipe,”

’817 patent, col.8, l.61-62, the doctrine of claim

differentiation requires claim 6 to be read broadly enough to

encompass a version of the invention wherein the vent is not a

pipe. As an initial matter, because the court construes the

disputed phrase, in part, as “a separate hollow fitting,” claim

6--as well as all of the other claims at issue--could encompass a

vent comprised of structure besides a pipe, as already discussed.

Furthermore, “the doctrine of claim differentiation is not a

hard and fast rule,” but simply “create[s] a presumption that

each claim in a patent has a different scope,” and “[t]hat

presumption is especially strong when the limitation in dispute

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 24 of 27
25

is the only meaningful difference between an independent and 

dependent claim.” SunRace Roots Enter., 336 F.3d at 1302-03

(internal quotation marks omitted). Here, “pipe” is not the only

meaningful difference between independent claim 6 and its

dependent claim 7: claim 7 discloses not only a pipe, but that

the upper end of the vent pipe has a floatable element

. . . so as to prevent . . . liquid from entering the

sealable compartment through the vent pipe when the 

. . . liquid rises in the waste water basin to move the

floatable element to seal the vent pipe.

’817 patent, col.8, l.62-67. This disclosure, which appears to

correspond to the vent equipped with the float valve discussed

supra, contains a number of limiting elements besides “pipe”

itself. As the Federal Circuit has instructed, “that the claims

are presumed to differ in scope does not mean that every

limitation must be distinguished from its counterpart in another

claim, but only that at least one limitation must differ.” Kraft

Foods, Inc. v. Int’l Trading Co., 203 F.3d 1362, 1368 (Fed. Cir.

2000). Because there are a number of limitations present in

claim 7 that are absent from claim 6, the doctrine of claim

differentiation does not support BMP’s view that “vent” means

simply “opening,” particularly where, as discussed at length,

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 25 of 27
13Because the court considers the meaning of the disputed

phrase clear from this intrinsic evidence, the extrinsic evidence

submitted by NEF has not been considered.

26

that reading finds no support in the language of the claims

themselves, the specification, or the prosecution history.13

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 26 of 27
27

IV. CONCLUSION

For the foregoing reasons, the court construes the phrase “a

vent mounted on the wall of said hood and extending upwardly

therefrom” to mean “a separate hollow fitting affixed to the wall

of said hood, said fitting having a lower end communicating with

a hole in the wall of the outlet hood and an upper end extending

upwardly from said hood to a position above said hood.” 

SO ORDERED.

____________________________

Joseph N. Laplante

United States District Judge

May 12, 2008

cc: David A. Anderson, Esq.

Richard J. Basile, Esq.

Walter B. Welsh, Esq.

Scott E. Daniels, Esq.

Case 1:07-cv-00151-JL Document 45 Filed 05/12/08 Page 27 of 27