Simpson Strong-Tie Company Inc. v. Columbia Insurance Company

NOTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
SIMPSON STRONG-TIE COMPANY INC.,
Appellant
v.
COLUMBIA INSURANCE COMPANY,
Appellee
______________________
2023-1944
______________________
Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. PGR2021-
00109.
______________________
Decided: January 7, 2025
______________________
RICHARD CRUDO, Sterne Kessler Goldstein & Fox
PLLC, Washington, DC, argued for appellant. Also repre-
sented by K RISTINA CAGGIANO K ELLY , MICHELLE
HOLOUBEK, WILLIAM MILLIKEN.
BRADLEY SCOTT E IDSON, Stinson LLP, St. Louis, MO,
argued for appellee. Also represented by K URT J AMES ,
J OHN R. SCHROEDER.
______________________
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SIMPSON STRONG- TIE COMPANY INC. v.
COLUMBIA INSURANCE COMPANY
2
Before REYNA, T ARANTO, and CHEN, Circuit Judges.
T ARANTO, Circuit Judge.
Columbia Insurance Co. owns U.S. Patent No.
11,021,867. After Columbia brought an infringement ac-
tion against Simpson Strong-Tie Company, Inc., Simpson
petitioned the Patent and Trademark Office (PTO) to insti-
tute a post-grant review, under 35 U.S.C. § 321, of all the
claims of the ’867 patent for unpatentability. See generally
35 U.S.C. §§ 321–329. The PTO’s Patent Trial and Appeal
Board, acting for the PTO’s Director, instituted the post-
grant review and eventually determined in its final written
decision that most, but not all, claims of the ’867 patent
were unpatentable, as Simpson asserted. At issue before
this court are several claims that survived the review. In
particular, the Board rejected indefiniteness and enable-
ment challenges to claims 13, 14, and 18–20 of the patent
as issued and to substitute claim 32 added during the re-
view. Simpson Strong-Tie Co. v. Columbia Insurance Co.,
PGR2021-00109, 2023 WL 2598961, at *4 (P.T.A.B. Mar.
15, 2023) (Decision).
Simpson appeals. We clarify that, for one claim (and
its dependents) modified by a certificate of correction under
35 U.S.C. § 255 after the post-grant review was sought, the
Board’s final written decision adjudicates the patentability
only of the uncorrected version, not the corrected version.
With that clarification of the decision’s scope, we affirm.
I
A
The ’867 patent describes a hanger for use in construct-
ing buildings—specifically, for attaching a horizontal piece
such as a joist or floor truss to a vertical wall when extra
wallboard or similar sheathing is to be added to the wall
for fire-retardant purposes. ’867 patent, col. 1, lines 19–21,
32–36; id., col. 3, lines 63–64; id., col. 4, lines 18–24, 31–33.
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SIMPSON STRONG- TIE COMPANY INC. v.
COLUMBIA INSURANCE COMPANY
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One embodiment is illustrated by the below figure. In that
embodiment, a channel-shaped portion (38) supports the
structural component (not shown) that sits on the base (44)
between its side walls (46) and butts up to the back wall(s)
of this portion (48). A connection portion (42) is used to
attach the hanger (26) to the wall framing (not shown) and
contains flat back flanges (66) that lie on the building’s wall
(and are parallel to the channel portion’s back wall(s) (48)).
An extension portion (40) contains extension flanges (60)
perpendicular to the back flanges that extend to meet the
channel portion’s back wall(s) (48). The space (68) between
the back flanges (66) and the channel portion’s back wall(s)
(48) is where fire-retardant sheathing (not shown) fits. Id.,
col. 2, lines 45–50; id., col. 4, lines 34–37; id., col. 5, lines
1–3.
Id., Fig. 2.
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SIMPSON STRONG- TIE COMPANY INC. v.
COLUMBIA INSURANCE COMPANY
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Independent claim 1 of the ’867 patent, on which claims
13 and 14 depend, recites:
A hanger for connecting a structural component to
a wall adapted to have sheathing mounted thereon,
the hanger comprising: . . .
an extension portion including first and second ex-
tension flanges extending from the channel-shaped
portion to the connection portion, each extension
flange being configured to extend through the
sheathing, each extension flange lying in an
extension flange plane, the extension flange
planes being generally perpendicular to the base
plane, the back flange and the channel-shaped por-
tion defining a sheath space sized and shaped to
receive the sheathing therein so that the channel-
shaped portion is located on one side of the sheath-
ing and the back flange is located on an opposite
side of the sheathing when the hanger and sheath-
ing are installed on the wall.
Id., col. 12, lines 15–44 (emphasis added).
Independent claim 161 of the ’867 patent, on which
claims 18–20 depend, recites:
A hanger to connect a joist to a frame wall adapted
to have sheathing mounted thereon so that an in-
terior side of the sheathing faces the frame wall
and an exterior side of the sheathing faces away
from the frame wall, the frame wall including a
wooden upper plate and wooden studs extending
down from the upper plate, the hanger comprising:
1 The “a joist” language, which appeared in the orig-
inal version of this claim, was later changed to “a structural
component” by a certificate of correction. See infra I.B.
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SIMPSON STRONG- TIE COMPANY INC. v.
COLUMBIA INSURANCE COMPANY
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a channel-shaped portion configured to re-
ceive the structural component, the
channel-shaped portion including a base
configured to receive an end portion of the
structural component thereon to support
the structural component and side panels
extending upward from the base; . . . .
Id., col. 13, line 34 through col. 14, line 17 (emphases
added).
Substitute independent claim 24 of the ’867 patent, on
which substitute claim 32 depends, recites:
A hanger for connecting a structural component to
a wall adapted to have sheathing mounted thereon,
the hanger comprising:
a channel-shaped portion configured to receive the
structural component, the channel-shaped portion
including a base configured to receive an end por-
tion of the structural component thereon to support
the structural component, the base having an up-
per surface configured to engage the structural
component, the upper surface lying in a base plane;
a connection portion configured for attachment to
the wall, the connection portion including a back
flange having an upper edge, the back flange ex-
tending from the upper edge in a direction gener-
ally toward the base plane, the connection portion
and channel-shaped portion being in a rigidly fixed,
spaced apart relation relative to one another as
manufactured; and
an extension portion including first and second ex-
tension flanges extending from the channel-shaped
portion to the connection portion, each extension
flange being configured to extend through the
sheathing, each extension flange lying in an exten-
sion flange plane throughout its extent from the
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SIMPSON STRONG- TIE COMPANY INC. v.
COLUMBIA INSURANCE COMPANY
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channel-shaped portion to the connection portion,
the extension flange planes being generally per-
pendicular to the base plane, the first and second
extension flanges and the channel-shaped portion
being formed as one piece of sheet metal, the back
flange and the channel-shaped portion defining a
sheath space sized and shaped to receive the
sheathing therein so that the channel-shaped por-
tion is located on one side of the sheathing and the
back flange is located on an opposite side of the
sheathing when the hanger and sheathing are in-
stalled on the wall.
J.A. 899–900 (cleaned up).
B
Simpson petitioned the Board for a post-grant review
of claims 1–23 of the ’867 patent on August 13, 2021. Simp-
son Strong-Tie Co. v. Columbia Insurance Co., PGR2021-
00109, 2021 WL 3610030 (P.T.A.B. Aug. 13, 2021) (Peti-
tion); see 35 U.S.C. § 321. Simpson argued that claims 1–
23 failed to meet the definiteness requirement of 35 U.S.C.
§ 112(b); claims 5 and 17 failed to have an adequate written
description as required by § 112(a); claims 1–4, 6, 10, and
11 were anticipated, i.e., failed to meet the novelty require-
ment of § 102; and claims 1–12, 15–17, and 21–23 claimed
obvious subject matter, and thus were unpatentable under
§ 103.
On November 30, 2021, before institution of a post-
grant review, Columbia notified the Board of its intent to
file a petition for a certificate of correction under 35 U.S.C.
§ 255. The Board noted that Columbia did not need to ask
its permission before making such a filing, but nonetheless
gave such permission; and it stated that it “d[id] not decide
at this juncture whether the proposed certificate of correc-
tion, if and when issued, would have effect in this proceed-
ing.” J.A. 367–68. On December 2, 2021, Columbia sought
a certificate of correction of claims 5, 11, 16, and 17, and
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SIMPSON STRONG- TIE COMPANY INC. v.
COLUMBIA INSURANCE COMPANY
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the correction issued on December 23, 2021. The correction
relevant to this appeal replaced “a joist” in the preamble of
claim 16 with “a structural component.”
The Board instituted a post-grant review on March 17,
2022. After institution, Columbia filed a contingent motion
to amend the claims under 35 U.S.C. § 326(d)(1), proposing
for particular claims in the patent as issued substitute
claims that the Board should consider if the corresponding
issued claims were held unpatentable. Simpson Strong-Tie
Co. v. Columbia Insurance Co., PGR2021-00109, Paper 46
at 1 (P.T.A.B. June 9, 2022) (Contingent Motion); see 37
C.F.R. § 42.221 (describing motion to amend practice). Co-
lumbia’s listing of the issued claims for which substitutes
were contingently proposed, however, used the versions
from the certificate of correction, J.A. 741 n.4, and the
Board indicated that Columbia should file a revised motion
“us[ing] the conventional underlining and strikethroughs
to designate the [] [c]orrections.” Simpson Strong-Tie Co.
v. Columbia Insurance Co., PGR2021-00109, Paper 51 at
4–5 (P.T.A.B. Sept. 26, 2022) (Preliminary Guidance) (em-
phasis omitted). Columbia did so, showing the corrections
“with additions underlined and deletions stricken-
th[r]ough or double bracketed.” Simpson Strong-Tie Co. v.
Columbia Insurance Co., PGR2021-00109, Paper 53 app. A
at 3 (P.T.A.B. Oct. 13, 2022) (Revised Contingent Motion).
Among the proposed amendments was substitute claim
32 for original claim 9. Revised Contingent Motion, at 7.
Substitute claim 32 depended indirectly on substitute
claim 24. Id. at 3–4, 6–7. Simpson challenged both claims,
as relevant here, for lack of enablement. Simpson Strong-
Tie Co. v. Columbia Insurance Co., PGR2021-00109, Paper
56 at 4 (P.T.A.B. Nov. 23, 2022) (Opposition to Contingent
Motion).
C
The Board issued its Final Written Decision on March
15, 2023. The Board held most claims unpatentable.
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SIMPSON STRONG- TIE COMPANY INC. v.
COLUMBIA INSURANCE COMPANY
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Decision, at *61. This appeal concerns only claims the
Board upheld. In summary: The Board determined that
claims 13, 14, and 18–20 were not shown to be unpatenta-
ble for indefiniteness, id. at *10–15, *61, and it granted Co-
lumbia’s motion to enter substitute claim 32 and
determined that it was not unpatentable for lack of enable-
ment, id. at *47–49.
More specifically, for claims 13 and 14, the Board re-
jected Simpson’s contention that the limitation “each ex-
tension flange lying in an extension flange plane”—in claim
1, on which claims 13 and 14 depend—rendered the claims
indefinite. Id. at *10–14. Simpson argued that the limita-
tion fails to inform a person of ordinary skill of “where the
[three-dimensional] ‘extension flange’ is located relative to
the [two-dimensional] ‘extension flange plane.’” Id. at *10.
The Board concluded otherwise, noting in particular “sev-
eral instances where prior art patents or published patent
applications for joist or structural component hangers de-
scribe various three-dimensional objects or flanges as lying
in planes.” Id. at *11; see also id. at *13–14.
For claims 18–20, the Board rejected Simpson’s conten-
tion that the claim term “the structural component”—in
the body of claim 16, on which claims 18–20 depend—ren-
dered the claims indefinite because it lacked antecedent
basis. Id. at *14. The Board relied on the phrase “a joist”
in the preamble of claim 16. Id. at *14–15. The Board
agreed with Columbia that the relevant artisan “knows
that joists are a type of structural component” and thus
“would have understood [that] the term ‘a joist’ provided
antecedent basis for the term ‘the structural component.’”
Id. at *14 (citing J.A. 655–56).
For substitute claim 32, the Board rejected Simpson’s
contention that the claim was not enabled because, like
claim 24 on which it depended, it did not claim “a top flange
having fastening elements,” which Simpson asserted was
“essential” for the operability of the described hanger. Id.
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SIMPSON STRONG- TIE COMPANY INC. v.
COLUMBIA INSURANCE COMPANY
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at *47. The Board found no expert testimony to support
Simpson’s assertion that “the skilled artisan would not
have been able to practice the claimed invention, where it
includes hangers without top flanges, without undue ex-
perimentation.” Id. at *48. The Board also noted that the
specification itself discloses that “[o]ther configurations are
within the scope of the present invention, such as a differ-
ent number of nail holes, or alternate fastening structure
such as nailing teeth or other appropriate structure for fas-
tening the hanger to the wall” and concluded that Simp-
son’s “impossibility” argument was not convincing. Id.
(emphasis omitted). The Board further explained that
Simpson’s expert testimony that “face-mounted hangers
were known in the art and that the skilled artisan would
have been familiar with face-mounted hangers” contra-
dicted Simpson’s arguments of undue experimentation. Id.
at *49.
The Director denied Simpson’s request for Director Re-
view on May 8, 2023, and Simpson timely filed its notice of
appeal on May 17, 2023. See 35 U.S.C. §§ 141(c), 329; 37
C.F.R. § 90.3(a)(1). We have jurisdiction under 28 U.S.C.
§ 1295(a)(4)(A).
II
We review the Board’s legal conclusions without defer-
ence and its factual findings for substantial evidence. In re
Gartside, 203 F.3d 1305, 1316 (Fed. Cir. 2000). We decide
de novo whether challenged agency action is “not in accord-
ance with the law or without observance of procedure re-
quired by law.” EmeraChem Holdings, LLC v. Volkswagen
Group of America, Inc., 859 F.3d 1341, 1345 (Fed. Cir.
2017) (cleaned up) (citing 5 U.S.C. § 706).
Whether a claim construction is correct is a question of
law, with analysis of intrinsic evidence reviewed without
deference and any relevant subsidiary factual findings re-
viewed for substantial evidence. Teva Pharmaceuticals
USA, Inc. v. Sandoz, Inc., 574 U.S. 318, 329, 331–32 (2015);
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SIMPSON STRONG- TIE COMPANY INC. v.
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In re CSB-System International, Inc., 832 F.3d 1335, 1340
(Fed. Cir. 2016). Indefiniteness and enablement are both
questions of law decided de novo, but findings of factual
underpinnings are reviewed for substantial-evidence sup-
port. See Akzo Nobel Coatings, Inc. v. Dow Chemical Co.,
811 F.3d 1334, 1343 (Fed. Cir. 2016) (discussing indefinite-
ness); Trustees of Boston University v. Everlight Electronics
Co., 896 F.3d 1357, 1361 (Fed. Cir. 2018) (discussing ena-
blement). A claim is unpatentable for indefiniteness if it
“fail[s] 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). A
claim is unpatentable for lack of enablement if it does not
“teach those skilled in the art how to make and use the full
scope of the claimed invention without undue experimen-
tation.” Trustees, 896 F.3d at 1362 (citing Genentech, Inc.
v. Novo Nordisk A/S, 108 F.3d 1361, 1365 (Fed. Cir. 1997))
(internal quotation marks omitted); see Amgen Inc. v.
Sanofi, 598 U.S. 594, 610, 612 (2023) (stating that “the
specification must enable the full scope of the invention as
defined by its claims” and that “a specification may call for
a reasonable amount of experimentation to make and use
a patented invention”).
A
We begin with Simpson’s argument that claims 13 and
14 are indefinite because they “fail[] to define the extension
flange plane with reasonable certainty.” Simpson Opening
Br. at 38. As part of this argument, Simpson challenges
the Board’s construction of the relevant claim term. Id. at
47–51. Simpson’s arguments are unpersuasive.
The Board construed “each extension flange lying in an
extension flange plane” as requiring that “for each exten-
sion flange[,] an extension flange plane is within the extent
of the extension flange from the channel-shaped portion to
the connection portion.” Decision, at *13. Simpson chal-
lenges that construction on the ground that it “does not
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SIMPSON STRONG- TIE COMPANY INC. v.
COLUMBIA INSURANCE COMPANY
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account for the extension flanges’ bends” and, actually,
could not do so, because “requiring the entirety of the ex-
tension flanges to lie in a plane effectively makes it impos-
sible for a multi-planar extension flange to satisfy the
limitation.” Simpson Opening Br. at 49–50. Relatedly,
Simpson contends that, with a two-dimensional “plane” re-
quired, a skilled artisan could not tell where on the three-
dimensional flange the relevant plane is, making the claim
language indefinite. Id. at 41–42.
One problem with Simpson’s argument is that it mis-
reads the Board’s construction as requiring the flange to lie
entirely within the plane, when the Board’s construction
requires something like the opposite, i.e., that the plane be
within the extent of the flange. Decision, at *13. A second
problem is that the Board plainly did “account for the ex-
tension flanges’ bends,” Simpson Opening Br. at 49, ex-
plaining, with reference to an illustration, that “the bends
(or bent portions) at the ends of the extension flanges . . .
have radiuses small enough to allow an extension flange
plane to remain within the extent of the extension flange
from the channel-shaped portion to the connection portion,”
Decision, at *12.
Simpson’s challenge rests at bottom on reading the
claim language, which does refer to a flange lying in a
plane, as having a mathematical (geometrical) meaning—
i.e., as using “plane” as something having only two dimen-
sions, which cannot contain a three-dimensional, multi-
planar object. The “impossib[ility]” of that result, Simpson
Opening Br. 49–50, shows that the Board was correct to
reject the attribution of a mathematical meaning in the
present context, which instead calls for a meaning in which
“plane” refers to an orientation of a (largely planar) object.
Decision, at *12. Though perhaps not necessary, expert
testimony explained that, in this context, the relevant ar-
tisan “would recognize that when the phrase ‘lying in a . . .
plane’ is used in reference to a three[-]dimensional object—
in this case the extension flange—the end-to-end extension
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of the object can be effectively described as being arranged
in the plane.” J.A. 3597–98 ¶ 119. And the usage is con-
firmed by “various prior art references,” which “describe
objects, particularly joist hanger objects, as lying in
planes.” Decision, at *11 (citing J.A. 3602–13 ¶¶ 128–44);
see In re Cortright, 165 F.3d 1353, 1358 (Fed. Cir. 1999)
(“Prior art references may be ‘indicative of what all those
skilled in the art generally believe a certain term means.’”
(quoting Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576,
1584 (Fed. Cir. 1996))). These references include two of
Simpson’s own patent applications, both of which describe
three-dimensional objects as lying in a plane. See, e.g., J.A.
3602 ¶ 130 (“stiffening elements”); J.A. 3603 ¶ 131 (“return
leg(s)”); J.A. 3604 ¶ 132 (“flanges”).
Correcting Simpson’s misunderstanding of the claim
language defeats almost all of Simpson’s indefiniteness ar-
guments. Simpson makes one indefiniteness argument
that is related but slightly different. It asserts that the
claims are indefinite because they take an “internally in-
consistent approach for defining the planes,” pointing to
another limitation that defines the “base plane” by refer-
ence to the base’s “upper surface.” Simpson Opening Br. at
39–41; see ’867 patent, col. 12, lines 22–24 (“the base hav-
ing an upper surface configured to engage the structural
component, the upper surface lying in a base plane”). But
the in-context meaning of “plane” to designate orientation
can apply to both an object like a flange and a “surface” of
such an object. This other claim language does not contra-
dict the proper orientation understanding of “plane” and
“lying in” language or, therefore, show indefiniteness. Ac-
cordingly, we agree with the Board that claims 13 and 14
are not unpatentable for indefiniteness.
B
We reject Simpson’s challenge to the Board’s upholding
of claims 18–20 as well. Simpson Opening Br. at 26–38.
This challenge focuses on language in claim 16 as issued,
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on which claims 18–20 depend: “a channel-shaped portion
configured to receive the structural component, the chan-
nel-shaped portion including a base configured to receive
an end portion of the structural component thereon to sup-
port the structural component and side panels extending
upward from the base.” ’867 patent, col. 13, lines 40–45.
Before the certificate of correction, the preamble referred
to “a joist”; after, it referred to “a structural component.”
See supra p. 7.
1
We see no reversible error in the Board’s rejection of
Simpson’s indefiniteness challenge to the pre-corrected
version of claim 16. Simpson argues that the phrase “the
structural component” in the body of the claim requires an
antecedent (because of “the”) but that it is unclear what
that antecedent is. We disagree. It is clear what the ante-
cedent is—namely, the phrase “a joist” in the preamble. It
is a familiar role for preambles to provide antecedents for
phrases in the body of the claim. See, e.g., In re Fought,
941 F.3d 1175, 1178 (Fed. Cir. 2019). That is just what “a
joist”—and only “a joist”—does.
The phrase “the structural component” in the claim
body therefore means “a joist.” It has an antecedent basis
that itself has not been shown to lack a meaning that would
be reasonably certain to a relevant artisan. Nautilus, 572
U.S. at 901. That conclusion appears sufficient to uphold
the Board’s rejection of the indefiniteness challenge.
But it is worth adding the following about the claim
limitation as a whole (quoted above), given a contention
made by Columbia. The claim body’s phrase (with the
“joist” meaning) limits what is claimed, as it helps define a
property of the claimed hanger—by what it is “configured
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to” allow to fit into it and be carried by it.2 But the claim
does not require actual use of a joist, rather than, say, a
truss. And it may well be that a hanger configured to re-
ceive and carry a joist is not materially different from one
configured to receive and carry a truss (or any other con-
templated “structural component”), as suggested by the
specification’s repeated treatment of at least joists and
trusses together. See ’867 patent, col. 1, lines 32–36; id.,
col. 4, lines 10–12; see also J.A. 3623–24 ¶¶ 174, 175.
We conclude that we have been presented no persua-
sive basis for upsetting the Board’s rejection of the indefi-
niteness challenge to pre-correction claim 16 or, therefore,
claims 18–20, which depend on pre-correction claim 16.
2
We also conclude that the Board did not, in fact, adju-
dicate the patentability of post-correction claim 16 or,
therefore, post-correction claims 18–20.
In the institution decision, the Board assessed the in-
definiteness challenge to claim 16 “based on the original
phrasing.” J.A. 524. The Board did not indicate that it
would be adjudicating the post-correction version when it
insisted that Columbia alter its presentation in the contin-
gent motion to amend, as described supra p. 7. In the final
written decision, the Board indicated that it had not
reached a conclusion about “whether the Certificate of Cor-
rection has effect in this proceeding.” Decision, at *14 n.4,
*15; see also J.A. 368 (Dec. 2, 2021 Order). The Board
stated that “[its] determination as to [Simpson’s] indefi-
niteness challenge is based on the original phrasing of
2 Simpson suggests that the Board determined that
the preamble of claim 16 was not “limiting,” Simpson Open-
ing Br. at 38, but that assertion is incorrect, as the Board
found the preamble of only claim 1, not 16, to be non-limit-
ing. See Decision, at *19–20.
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claim 16.” Decision, at *15 (emphasis added). When it
added that it “would reach the same result regardless of
whether the Certificate of Correction has effect in the pro-
ceeding,” id. (emphasis added), it was stating only a self-
evident truism: When the sole basis for the indefiniteness
contention about claim 16 (the fact that “the structural
component” was not identical to “a joist”) was eliminated,
of course the indefiniteness challenge on that basis would
be meritless.
We see nothing in the final written decision that fairly
supports an understanding of the decision as adjudicating
the patentability of post-correction claim 16 (or the deriva-
tively corrected dependent claims). Given our clarification
in that way of the scope of the Board’s decision, Simpson
agrees that we need not address its arguments about pro-
cess errors by the Board. Oral Arg. at 00:40–01:01,
https://oralarguments.cafc.uscourts.gov/default.aspx?fl=23
-1944_12062024.mp3.
C
Simpson’s final argument is that substitute claim 32 is
not enabled because, like substitute claim 24 (on which it
indirectly depends), it does not claim the “top flanges”—
which Simpson says are “essential” because, without them,
the claimed invention would be “inoperable.” Simpson
Opening Br. at 52–54. The Board rejected that argument.
Decision, at *47–49. We agree with the Board.
First, the specification does not support Simpson’s ar-
gument that the top flanges are “essential.” Rather, the
specification contains a “broad disclosure” describing other
means of attachment: “Other configurations are within the
scope of the present invention, such as a different number
of nail holes, or alternate fastening structure such as nail-
ing teeth or other appropriate structure for fastening the
hanger to the wall.” ’867 patent, col. 6, lines 53–57, quoted
in Decision, at *48. The specification also repeatedly refers
to “a connection portion [] configured for attachment to the
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SIMPSON STRONG- TIE COMPANY INC. v.
COLUMBIA INSURANCE COMPANY
16
wall,” without limiting such connection portion to a top
flange. ’867 patent at Abstract; id., col. 2, lines 18–19, 49–
50. Because the specification indicates that the top flanges
are not “essential,” Simpson’s position is not supported by
our predecessor court’s decision in In re Mayhew, which in-
volved a claimed invention that was “practicable because
of” the essential feature and a patent that did not contem-
plate an embodiment without that feature. In re Mayhew,
527 F.2d 1229, 1232–33 (CCPA 1976).
The Board considered Simpson’s argument that expert
testimony offered by Columbia conceded inoperability
without the top flanges, but it determined that Simpson
was “mischaracterizing the . . . testimony.” Decision, at
*48. It explained that “Dr. Serrette testifie[d] that the spe-
cific hanger shown in the drawings of the ’867 patent, spe-
cifically Figure 2, would be inoperable if one simply cut off
the top flanges,” not that the relevant artisan would be un-
able to practice the claimed invention without undue ex-
perimentation. Id. (emphasis added). The Board further
found that Simpson cited “no testimony from [its own ex-
pert] Mr. Fennell that the skilled artisan would not have
been able to practice the claimed invention, where it in-
cludes hangers without top flanges, without undue experi-
mentation.” Id. Relatedly, the Board found that prior art
describing face mounted (as opposed to top mounted) hang-
ers “plainly contradicts [Simpson’s] allegation that it would
have been ‘impossible’ or would have required undue ex-
perimentation for the ordinarily skilled artisan to have
practiced the claimed invention, where it includes hangers
without top flanges (i.e., is a face mount hanger rather than
a top mount hanger).” Id. at *49. We see no reversible er-
ror in those determinations or in the Board’s rejection of
the enablement challenge to substitute claim 32.
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SIMPSON STRONG- TIE COMPANY INC. v.
COLUMBIA INSURANCE COMPANY
17
III
For the foregoing reasons, we affirm the Board’s final
written decision as to claims 13, 14, 18–20, and substitute
claim 32.
AFFIRMED
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