RT-FILTERTECHNIK GMBH

Patent Trials and Appeals Board

Dec 2, 2021

2021004618 (P.T.A.B. Dec. 2, 2021)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
16/239,736 01/04/2019 Gerhard STEHLE 2018-1321 2060
513 7590 12/02/2021
WENDEROTH, LIND & PONACK, L.L.P.
1025 Connecticut Avenue, NW
Suite 500
Washington, DC 20036
EXAMINER
JOHNSON, JERRY D
ART UNIT PAPER NUMBER
3991
NOTIFICATION DATE DELIVERY MODE
12/02/2021 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
eoa@wenderoth.com
kmiller@wenderoth.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
______________
BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________________

Ex parte GERHARD STEHLE and DIRK SCHOENFELD
____________________

Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2
Technology Center 3900
____________________

Before MICHELLE R. OSINSKI, JILL D. HILL and CYNTHIA L.
MURPHY, Administrative Patent Judges.

HILL, Administrative Patent Judge.
DECISION ON APPEAL

STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant appeals from the
Examiner’s decision to reject the single design claim pending in this appeal.1
We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.

1 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R.
§ 1.42. Appellant identifies RT-FILTERTECHNIK GMBH as the real party
in interest. Appeal Br. 1.
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

2
BACKGROUND
US Patent 9,849,408 (“the ’408 Patent”) issued from U.S. Application
13/261,592, filed February 11, 2013 (“the ’592 Application”). Appellant’s
claimed invention is directed to a filter element. ’408 Patent, Title. The
’408 Patent issued with claims 1–15. Original claims 1 and 4–15 remain
pending and are indicated as allowable by the Examiner. Claims 16–20 are
added in this reissue examination and are rejected. Claim 16 is independent,
and is reproduced below as representative of the claims on appeal, with
certain limitations italicized.
16. A filter element, comprising:
an inner jacket body having an outer contact face with a
cross-sectional shape of a Reuleaux polygon;
an outer jacket body with an inner contact face with a
circular cross-sectional shape; and
a pleated filter web consisting essentially of filter folds
divided at least first, second and third individual groups of a
plurality of said filter folds arranged alongside each other in
sections, said filter folds being between said inner and outer
jacket bodies and contacting the respective contact faces, each
of said filter folds having a fold height, each of said filter folds
in each of said first and second groups having a common or
equal fold height in the respective individual group, said filter
folds of said third individual group being arranged between two
adjacent filter folds of said first and second individual groups,
said filter folds of said third individual group having different
fold heights relative to each other, said different fold heights of
said third individual group being different from the respective
fold heights of the filter folds of adjacent adjoining first and
second individual groups and being less than the fold height of
said first individual group and being greater than the fold height
of said second individual group, said filter folds of said third
individual group adjacent said first and second individual
groups transitioning in a step formation from said filter folds of
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

3
said third individual group to said filter folds of said first and
second individual groups, said filter folds of said first, second
and third individual groups forming an inner cross-sectional
shape of a Reuleaux polygon conforming to said outer contact
face of said inner jacket and an outer cross-sectional shape of a
circle conforming to said inner contact face of said outer jacket.

REJECTIONS
I. Claims 16–20 stand rejected under 35 U.S.C. § 112, second
paragraph, as indefinite. Final Act. 6–7.
II. Claims 16–20 stand rejected under 35 U.S.C. § 251 as an
impermissible recapture of surrendered subject matter. Final Act. 7.

ANALYSIS
We review the appealed rejections for error based upon the issues
identified by Appellant and in light of the arguments and evidence produced
thereon. Ex parte Frye, 94 USPQ2d 1072, 1075 (BPAI 2010) (precedential)
(cited with approval in In re Jung, 637 F.3d 1356, 1365 (Fed. Cir. 2011)
(“[I]t has long been the Board’s practice to require an applicant to identify
the alleged error in the examiner's rejections.”)).
Indefiniteness
Claim 16 recites the “filter folds of said third individual group having
different fold heights relative to each other” and the “third individual group .
. . transitioning in a step formation from said filter folds of said third
individual group to said filter folds of said first and second individual
groups.” The Examiner finds, however, that the ’408 Patent’s original
disclosure teaches that “step formations” are characterized by “individual
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

4
groups having a common fold height that produces a ‘sharp transition’
between filter fold heights of adjacent groups.” Final Act. 7.
Appellant argues that the Examiner erred in “basing the rejection on
the misinterpretation that a step formation must be from or to an individual
group of folds with a common fold height.” Appeal Br. 3. According to
Appellant, “step formations can and are disclosed to be to and from
individual group III with folds of different fold heights.” Id. According to
Appellant, claim 16 recites filter folds of Group III “that are adjacent the
first and second individual groups that transition in a step formation,” which
is shown in Appellant’s Figure 2b.2 Id.
Appellant explains that the Group III filter fold tips “are analogous to
the exposed edges of the steps of a stairway from a lower floor or landing to
an upper floor.” Id. at 4. Appellant contends that the Examiner is limiting
claim 16 to the embodiments of its Figures 1 and 4, improperly excluding
the embodiment of Figure 2b. Id. Appellant also contends that Figure 2b
was covered by claim 2 of the ’408 Patent, and therefore was not
surrendered. Id.
A decision on whether a claim is indefinite requires a determination of
whether a skilled artisan would understand what is claimed when the claim
is read in light of the specification. See Power-One, Inc. v. Artesyn Techs.,
Inc., 599 F.3d 1343, 1350 (Fed. Cir. 2010); Orthokinetics, Inc. v. Safety
Travel Chairs, Inc., 806 F.2d 1565 (Fed. Cir. 1986). Appellant contends
that a skilled artisan would understand the subject matter of claim 16 “when

2 Appellant refers to an annotated version of its Figure 2b with “steps” a
through e (Appeal Br. 3–4); however, Appellant’s Appendix B does not
include the referred-to figure.
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

5
the claim is read in light of . . . Fig. 2b and the description of the
embodiment of Fig. 2b” in Appellant’s Specification. Appeal Br. 5.
The Examiner responds that the indefiniteness rejection “is not
predicated on limiting claim 16 to the Fig. 4 embodiment to the exclusion of
the Fig. 2b embodiment,” but instead on the teachings of the ’408 Patent
disclosure as a whole. Ans. 3–4. The Examiner cites to Appellant’s
Specification, which discusses a third group of filter folds arranged between
the first and second groups of filter folds, the third group of filter folds
having
in the manner of a step formation . . . a common fold height,
which fold height is different from the respective fold height of
the filter folds of the two adjacent adjoining groups, and/or . . .
in the manner of a curve formation mutually different fold
heights to produce a transition between the fold heights of the
two adjacent groups.
Ans. 4 (citing, inter alia, ’408 Patent 2:6–14 (emphasis added by
Examiner)). The Examiner further cites the ’408 Patent’s disclosure that the
folds of the third group have the same height, or “[a]s an alternative, the
fold height of the corresponding filter folds assigned to the third group can
be designed to follow a wave-shape and/or sine-shaped progression.” Id.
(citing, inter alia, ’408 Patent 2:51–54 (emphasis added by Examiner)).
This disclosure, the Examiner contends, “teaches that the third group
produces a transition between the fold heights of the two adjacent groups in
two different ways: 1) a step formation having a common fold height, or 2) a
curve formation having mutually different fold heights.” Id. (emphasis
added). According to the Examiner, the ’408 Patent thus teaches that “step
formations are characterized by individual groups having a common fold
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

6
height that produces a ‘sharp transition’ between filter fold heights of
adjacent groups as shown in Fig. 1b and Fig. 4.” Id. at 6. As a result, the
Examiner contends, “claims 16-20 are indefinite by requiring the third
individual group [of filter folds] to have different fold heights relative to
each other and also form a step formation transition between filter folds of
the first and second individual groups.” Id.
We agree with the Examiner that Appellant’s Specification discloses
what Appellant refers to as “stepped” third group filter fold height
embodiments in its Figures 1 and 4, which are distinct from the “direct
succession” (’408 Patent 2:30–31) third group filter fold height embodiment
of Figures 2a and 2b that increases or decreases “continuously” (’408 Patent
5:50–61) and the third group filter fold heights of the embodiment of Figures
3a and 3b that “avoid sharp transitions” and increase/decrease “in a flowing
or continuous manner” (’408 Patent 3:43, 6:25–30). Thus, the ’408 Patent
itself appears to distinguish between a stepped transition in Group III where
the filter folds have common heights, and a continuous filter fold height
change in Group III.
Further, we disagree with Appellants’ contention that its Specification
teaches “step formations” including folds having different fold heights, and
we likewise disagree that the fold heights shown in Appellants’ Figure 2b
are described in Appellant’s Specification as being stepped.
Despite our agreement with the Examiner on this issue, and our
disagreement with Appellant’s contention that its Figure 2b can be properly
described as stepped, we are not persuaded that claim 16 is indefinite,
because a skilled artisan would have, like the Examiner and this panel,
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

7
understood what is claimed. The issue here is more a question of whether
the scope of claim 16 is contemplated by the original disclosure.
Recapture
This Application seeks a broadened reissue of the ’408 Patent. A
patentee can broaden claims in its issued patent within two years if the
patentee can show “error.” See 35 U.S.C. § 251 (the “Reissue Statute”).
However, not every circumstance “that might be labeled ‘error’ is
correctable by reissue.” Hester Indus., Inc. v. Stein, Inc., 142 F.3d 1472,
1479 (Fed. Cir. 1998). One circumstance “that does not satisfy the ‘error’
requirement” of the Reissue Statute “is embodied by the recapture rule.” In
re Youman, 679 F.3d 1335, 1343 (Fed. Cir. 2012). “The recapture rule bars
a patentee from recapturing subject matter, through reissue, that the patentee
intentionally surrendered during the original prosecution . . . to overcome
prior art.” Id. Determining whether reissue claims violate the recapture rule
requires a three-step analysis. Id. “Under the first step, we determine
whether and in what aspect the reissue claims are broader than the patent
claims.” Id. (internal quotations omitted). Under the second step, we
“determine whether the broader aspects of the reissue claims relate to
surrendered subject matter.” Id. (internal quotations omitted). If the reissue
claims are broader relative to the patented claims in a manner related to
surrendered subject matter, then under the third step, we “determine whether
the surrendered subject matter has crept into the reissue claim.” Id. at 1344.
Violation of the recapture rule, may be avoided if “the [reissue] claims
are materially narrowed in a way that avoids substantial or whole recapture
of the surrendered subject matter.” Id. at 1344–45. The materially
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

8
narrowing analysis is conducted on a limitation-by-limitation basis and the
frame of reference is the original claim. Id. at 1345, 1346; see also id. at
1347 (“[I]f the patentee modifies the added limitation such that it is broader
than the patented claim yet still materially narrows relative to the original
claim, the recapture rule does not bar reissue.”). “[A] limitation that is
added during prosecution to overcome prior art cannot be entirely eliminated
on reissue because doing so would constitute recapture of the surrendered
subject matter.” In re Mostafazadeh, 643 F.3d 1353, 1359 (Fed. Cir. 2011).
The Examiner finds that original independent claim 1 was replaced to
change the Group III filter fold height description from including “a step
formation having a common fold height . . . and/or . . . a curve formation
having different fold heights” to being limited to “a step formation having a
common fold height.” Final Act. 8–9; ’592 Application, Amendment of
November 14, 2013, p. 3. According to the Examiner, this claim
replacement limited the claims to a “step formation” with a common fold
height, surrendering the alternative embodiment “of a curve formation
having different fold heights.” Id. at 9. The Examiner asserts that the
recapture rule, thus, bars Appellant from recapturing the “curve formation
having different fold heights” subject matter surrendered in the claim
replacement. Id. We note, further, that remarks regarding this claim
replacement stated that using “each of the respective three groups having a
common or equal fold height . . . is not disclosed or rendered obvious from
the cited documents.” See ’592 Application, Request for Reconsideration
dated May 9, 2017, p. 2; ’592 Application, Amendment dated October 31,
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

9
2016, p. 8; ’592 Application, Amendment dated April 6, 2016, p. 8; ’592
Application, Amendment dated August 26, 2014, p. 8.
Regarding the three-step recapture analysis, the Examiner contends
that: (1) claims 16–20 “no longer require ‘each of said filter folds of said
third individual group in a step formation having a common or equal fold
height different from the respective fold heights of the filter folds of adjacent
adjoining first and second individual groups,’” making them broader in
scope than the original claims; (2) Appellant amended the original claims “to
require each of the filter folds of the third individual group to have a
common or equal fold height which differed from the adjacent adjoining first
and second individual groups in a step formation and argued those
limitations distinguished the claims from the applied prior art,” such that
“the broader aspects of the reissue claims relate to subject matter
surrendered in the original prosecution;” and (3) because the limitation of
the third individual group fold being “in a step formation” and “having a
common or equal fold height” was argued by Appellant to distinguish over
the prior art during prosecution of the ’592 Application, addition of a
narrowing limitation in an unrelated aspect does not prevent impermissible
recapture. Final Act. 10. The Examiner determines that claims 16–20 have
not been materially narrowed to prevent elimination of the limitation of the
third group filter folds being “‘in a step formation having a common or equal
fold height different from the respective fold heights of the filter folds of
adjacent adjoining first and second individual groups.’” Id. at 11.
Appellant argues that the Examiner errs by “basing the rejection on
the contention that any limitations added to the independent claim during the
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

10
prosecution of the original patent may not be changed, even when that
limitation is unnecessary to distinguish the prior art . . ., and related
narrowing recitations are added in the reissue claims.” Appeal Br. 6.
The Examiner answers that, in response to a prior art rejection during
prosecution of the ’592 Application, Appellant limited the claims to the
stepped embodiment of Group III filter folds having a “common or equal
fold height” by removing language drawn to an alternative limitation of filter
folds having a “curve[d] formation,” and argued those limitations
distinguished the claims from the applied prior art. Ans. 8, 9–10; ’592
Application, Amendment of November 14, 2013, p. 9 (“[T]he fold heights
[of Haberkamp] vary continuously so as not to have the common fold
heights in each of the respective first, second, and third individual groups.”).
Thus, the Examiner is certainly not contending that any limitations added
during prosecution of an original patent cannot be removed during reissue.
This argument is not persuasive of Examiner error.
Based on the evidence set forth above, we agree with the Examiner
that (1) claims 16–20 are broader in scope than the original claims because
they do not require the Group III filter folds to have a common or equal fold
height, and (2) during prosecution of the ’592 Application, Appellant
amended the original claims to require each of the Group III filter folds to
have a common or equal fold height, and argued that the common or equal
fold height limitation “distinguished the claims from the applied prior art,”
such that “the broader aspects of the reissue claims relate to subject matter
surrendered in the original prosecution.” Final Act. 10.
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

11
Appellant also argues that the above-discussed changes to the claim
language and argument regarding patentability over Haberkamp do not
establish “intentional surrender” of “step formation and common or equal
fold height” in Group III, because “a step formation and a common or equal
fold height in the third individual group were not required in the arguments
distinguishing Haberkamp.” Appeal Br. 6. According to Appellant, “[f]or
subject matter to be surrendered, there must be ‘a deliberate withdrawal or
amendment to secure the patent.’” Id. (citing Medtronic, Inc. v. Guidant
Corp., 465 F.3d 1360, 1375 (Fed. Cir. 2006)).
Regarding intentionality of the subject matter surrendered during
prosecution of the ’592 Application, the Examiner responds that “the
cancellation or amendment of the original claim . . . to overcome prior art is
a deliberate action that necessarily excludes the inadvertence or mistake
contemplated by the statute’s error requirement.” Ans. 11. We agree with
the Examiner that, in this case, Appellant’s removal of the non-stepped
embodiment by amendment, and subsequent argument that the common fold
height differentiates the claim from Haberkamp, leads to a logical
conclusion that the surrender of non-common fold heights was intentional.
Relevant to step (3) Appellant contends that Haberkamp was
distinguished during prosecution of the ’529 Application by arguing that the
embodiment of Haberkamp’s Figures 14 and 15 has continuously-variable
fold heights rather than “the common fold heights in each of the respective
first, second and third individual groups as recited in claim 15.” Appeal Br.
7. Appellant also contends that claim 16 still recites a step “at each end of
the third . . . group,” such that “the step formation limitation is not
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

12
eliminated” in claim 16 and “is made more specific by the reference to the
two filter folds adjacent the first and second individual groups.” Id. at 7–8.
Thus, Appellant argues, even if the original claims of the ’592 Application
covered the embodiment of Figs. 2a–2b and were amended to exclude that
embodiment, those circumstances need not constitute a surrender. Appeal
Br. 8 (citing Medtronic, 465 F.3d at 1375; In re Youman, 679 F.3d 1335
(Fed. Cir. 2012)). In fact, Appellant argues, changing claim scope from a
“common fold height to different fold heights in the third individual group is
not an elimination of the common fold height feature,” but rather “is a
material narrowing of a related feature that was recited in original patent
claim 2 [that was] never surrendered.” Id. at 8. Appellant contends that,
thus, “claim 16 corrects original patent claim 2 (now cancelled) to avoid the
inconsistency relative to the fold heights of the filter fold in the third
individual group.” Id.
Appellant further argues that the step formation is not eliminated in
pending claim 16, which requires the step formation “at each end of the third
individual group adjacent the first and second individual groups,” such that
“each claim 16 step formation is relative to an individual group with filter
folds of equal height to distinguish Haberkamp.” Appeal Br. 7–8.
The Examiner responds that Appellant’s argument is inconsistent with
the ’408 Patent’s teaching that “step formations are characterized by
individual groups having a common fold height that produces a ‘sharp
transition’ between filter fold heights of adjacent groups as shown in Fig. 1b
and Fig. 4.” Ans. 11. The Examiner contends that Appellant’s argument, “if
accepted, would completely eliminate the difference between filter folds of
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

13
the third group being in the manner of [1] a step formation or . . . [2] a curve
formation” as originally recited in the ’592 Application. Id. According to
the Examiner, eliminating this difference would be inconsistent with the
’408 Patent’s Specification, which “teaches that the third group produces a
transition between the fold heights of the two adjacent groups in two
alternative ways: 1) a step formation having a common fold height, or 2) a
curve formation having mutually different fold heights.” Id.
The Examiner has the better argument. Under the third step, “[u]nless
the claims are materially narrowed in a way that avoids substantial or whole
recapture of the surrendered subject matter, the surrendered subject matter
has crept into the reissue claims and they are barred under the recapture
rule.” In re Youman, 679 F.3d at 1344–45. As explained above, during
prosecution of the ’592 Application, Appellant amended only the limitation
regarding the fold height of the Group III filter folds. The overall story told
by carefully reviewing the original filing and prosecution of the ’592
Application is that Appellant surrendered its embodiment with non-
common/non-equal Group III fold heights to overcome Haberkamp as prior
art.
We are not persuaded that the recited “step” from the Group III filter
folds from or to each of the adjacent Group I or Group II filter folds can be
construed as the same “step” that is recited in claim 1 of the ’408 Patent,
which we understand from the Specification of the ’408 Patent to be a term
used to describe the formation of Group III filter folds when those folds have
a common height rather than any kind of flowing or continuous
increase/decrease in filter fold height that Appellant now seeks coverage for.
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

14
Thus, although claim 16 recites the term “step,” the common or equal fold
height of the Group III filter folds, which we determined was argued as
overcoming Haberkamp, has been eliminated in its entirety.
We are further not persuaded by Appellant’s argument that “claim 16
corrects original patent claim 2 (now cancelled) to avoid the inconsistency
relative to the fold heights of the filter fold in the third individual group.”
Appeal Br. 8. Original claim 2 of the ’408 Patent recites the Group III filter
fold heights “produc[ing] a transition between the fold heights of the
adjacent adjoining first and second individual groups.” Appellant fails to
explain how this transition producing recitation of claim 2 supports
Appellant’s position that there was no surrender of non-common filter fold
heights during prosecution of the ’592 Application, and an explanation is not
evident to us.
Appellant then argues that pending claim 16 “substitutes the common
or equal fold height of the filter folds of the third individual group of
original patent claim 1 with the filter folds of the third individual group
having different fold heights relative to each other,” which “materially
narrows this substituted limitation of patent claim 1 in related aspects to
avoid an impermissible recapture.” Appeal Br. 10. For the reasons
discussed above, we disagree that replacing common filter fold heights with
different filter fold heights, given the prosecution history of the ’592
Application, materially narrows the claim in a way that prevents recapture.
For the reasons explained above, we sustain the Examiner’s § 251
rejection of claim 16.
Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

15
Appellant argues that each of dependent claims 17 and 18 further
avoids impermissible recapture by reciting “the different fold heights of the
third individual group progressively changing between the fold height of the
first” and second groups. Appeal Br. 10. Similarly, Appellant argues that
each of claims 19 and 20 further avoids impermissible recapture by reciting
“the filter folds of each of the first, second and third individual groups have
different heights.” Appeal Br. 10–11.
We determine above that replacing common filter fold heights with
different filter fold heights does not materially narrow the claim in a way
that prevents recapture. Likewise, further defining the fold height
differences does no more to materially narrow the claims in a manner that
avoids recapture. Thus, we sustain the Examiner’s § 251 rejection of claims
16–20 as well.
DECISION SUMMARY
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
16–20 112 second
paragraph
Indefiniteness 16–20
16–20 251 Improper
Broadening,
Reissue
16–20
Overall
Outcome:
16–20
TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

Appeal 2021-004618
Application 16/239,736
Reissue of US Patent 9,849,408 B2

16
AFFIRMED