Ex Parte 6735874 et al

Board of Patent Appeals and Interferences

Sep 28, 2010

95000139 (B.P.A.I. Sep. 28, 2010)

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.
95/000,139 03/29/2006 6735874 086333.00009 8295
1218 7590 09/28/2010
HESPOS & PORCO LLP
110 West 40th Street
Suite 2501
NEW YORK, NY 10018
EXAMINER
FOSTER, JIMMY G
ART UNIT PAPER NUMBER
3993
MAIL DATE DELIVERY MODE
09/28/2010 PAPER
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.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

PROULX MANUFACTURING, INC.
Requester and Respondent

v.

Patent of KWIK PRODUCTS, INC.
Patent Owner and Appellant
____________

Appeal 2010-001227
Reexamination Control 95/000,139
Patent 6,735,874 B2
Technology Center 3900
____________

Before ROMULO H. DELMENDO, KARL EASTHOM, and
DANIEL S. SONG, Administrative Patent Judges.

DELMENDO, Administrative Patent Judge.

DECISION ON APPEAL1

1 The one-month time period for filing a request for rehearing, as recited in
37 C.F.R. § 41.79, and the two-month time period for filing an appeal, as
recited in 37 C.F.R. § 1.304 (see 37 C.F.R. § 1.983(b)(1)), both begin to run
from the “MAIL DATE” shown on the PTOL-90A cover letter attached to
this decision
Appeal 2010-001227
Reexamination Control 95/000,139
Patent 6,735,874 B2
2
Kwik Products, Inc., the owner of the patent under reexamination,
appeals under 35 U.S.C. §§ 134(b) and 315(a)(1) from the Examiner’s final
decision to reject claims 1-6 (Appeal Brief filed April 2, 2009, hereinafter
“App. Br.,” 1; Right of Appeal Notice, hereinafter “RAN,” mailed January
8, 2009). Proulx Manufacturing, Inc., the Third-Party Requester, is a party
to this appeal under 35 U.S.C. § 315(b)(2) and agrees with the Examiner on
all issues (Respondent Brief filed May 4, 2009, hereinafter “Resp. Br.,” 2).
The Requester, however, did not file a cross-appeal urging a different
ground of rejection based on different evidence and/or reasoning.
We have jurisdiction under 35 U.S.C. §§ 134(b) and 315. We
REVERSE.

STATEMENT OF THE CASE
The ‘874 Patent states that the invention relates to cutting heads for
rotary trimmers, which are used to cut vegetation (col. 1, ll. 11-14).
Claim 1, the only independent claim on appeal, reads as follows:
1. A cutting head for a rotary trimmer having two
diametrically opposed cutting flails which extend outwardly
from a spinning assembly including two major assemblies, a
cap assembly and a spool assembly having an axis of rotation, a
bumper for engagement with the ground and means to allow
predetermined lengths of flail to feed outwardly in response to
the striking of the bumper on the ground, the improvement
comprising:
a cam member having a cam slot therein connected to
one of said assemblies, said cam slot being a serpentinous cam
slot having one portion formed by the radial surface of a
washer, said cam slot being defined by radially extending tangs
which are radially spaced, with alternate tangs being spaced
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Patent 6,735,874 B2
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along said axis of rotation so as to define said serpentinous cam
slot, each said tang being of truncated, bell-shaped
configuration so as to avoid stress concentrations;
a follower member connected to the other of said
assemblies and having diametrically opposed cam followers
thereon positioned to ride in said cam slot, said follower
member further including six outwardly extending knobs, said
spool assembly surrounding said follower member and having
six grooves extending parallel to said axis of said spool
assembly, said grooves having parallel sidewalls, with two
diametrically opposed grooves having lateral cutouts at the
lower ends thereof for receiving two of said knobs, said two of
said knobs being positioned in said lateral cutouts to releasably
retain said follower member to said bumper;
said cam follower of the follower member being defined
by four radially spaced tangs extending radially inwardly of
said follower member, each said tang being of truncated, bell-
shaped configuration for minimizing stress concentrations when
said cam follower is engaged in said cam slot; and
biasing means acting between said cam member and said
follower member tending to urge said cam follower into stable
positions on said cam slot when undisturbed by force applied to
said bumper and adapted to be overcome by suitable force
applied to said bumper, said cam slot being generally parallel to
the force applied by said biasing means.
(Claims App’x, App. Br. 27-28.)

The Examiner relied upon the following as evidence of
unpatentability (Ans. 3-4):
Proulx 4,097,991 July 4, 1978
(Proulx ‘991)
Proulx 4,259,782 Apr. 7, 1981
(Proulx ‘782)
Proulx 4,458,419 July 10, 1984
(Proulx ‘419)
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Reexamination Control 95/000,139
Patent 6,735,874 B2
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Proulx 4,959,904 Oct. 2, 1990
(Proulx ‘904)
Tomita 2001/0016163 A1 Aug. 23, 2001
Takemura 2002/0073813 A1 June 20, 2002
S. Timoshenko & Gleason H. MacCullough, Elements of Strength of
Materials 24-25 (1935).
Stephen Timoshenko, Strength of Materials Part II: Advanced Theory
and Problems 498-99 (1956).
Declaration of Martin M. Balaban, Ph.D., filed March 28, 2006
(hereinafter “Balaban Declaration”), ¶¶ 15-17, 23, 27.
Declaration of Richard A. Proulx filed September 21, 2006
(hereinafter “Proulx Declaration”), ¶¶ 4, 6.

The Examiner rejected claims 1-6 under 35 U.S.C. § 103(a) as
follows:
I. Claims 1-6 as unpatentable over Proulx ‘782 in view of
Proulx ‘419, Proulx ‘991, Elements of Strength of
Materials, and Strength of Materials Part II: Advanced
Theory and Problems (Ans. 4; RAN 3-17); and
II. Claims 1-6 as unpatentable over Proulx ‘782 in view of
Proulx ‘419, Proulx ‘991, Elements of Strength of
Materials, Strength of Materials Part II: Advanced
Theory and Problems, Tomita, and Takemura (Ans. 4;
RAN 17-19).

ISSUES
The Examiner acknowledges that Proulx ‘782, the principal prior art
reference, does not describe tangs (on a cam member and a follower
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Patent 6,735,874 B2
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member) having “truncated, bell-shaped configuration[s] for minimizing
stress concentrations,” as recited in claim 1 (Ans. 5; RAN 7). The Examiner
asserts, however, that the “those portions of the truncated bell-shaped
configuration constituting rounded free ends of the tang . . . have not been
considered in the rejection to perform a structural function of any kind, but
only to involve what amounts to an ornamental design” (Ans. 5; RAN 9).
The Examiner expressed doubt that “the truncated bell-shaped
configurations in the trimmer disclosed by [the ‘874 Patent] will provide
greater contact surfaces or a reduction in stress concentrations over that of
the Proulx ‘419 configuration” (Ans. 5, 12; RAN 9). Notwithstanding these
assertions, the Examiner first relied on Proulx ‘419 for the proposition that
“providing the tangs such as those of Proulx ‘782 with tapering shapes”
would have “avoid[ed] excessive pressures” (Ans. 10; RAN 7-8). The
Examiner then relied on Elements of Strength of Materials, Strength of
Materials Part II: Advanced Theory and Problems, Tomita, and Takemura
for the proposition that these references would have further suggested fillets
or rounded corners in the tangs to reduce stress concentrations (Ans. 13, 18;
RAN 8, 17).
The Requester states that it “is in complete agreement with the
position of the Examiner in the [RAN]” (Resp. Br. 2).
The Patent Owner contends that the Examiner used impermissible
hindsight because the rejections rely on the disclosure of the ‘874 Patent as a
“blueprint” to reconstruct the claimed invention (App. Br. 13). According to
the Patent Owner, “there is no suggestion or teaching in either of the
publication references to provide fillets to the hypothetical, tapered tang
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structure which the Examiner has created, in a vegetation trimmer
environment where the contacting tangs violently engage each other” (App.
Br. 19). Specifically, the Patent Owner asserts that the “tangs” of Proulx
‘419 are already optimized in terms of contact area between the cam and the
cam follower to result in an “extremely robust, trouble-free and reliable”
device, and therefore a person of ordinary skill in the art would not have
further modified them in the manner proposed by the Examiner (App. Br.
19, partially quoting Proulx ‘419 at col. 2, ll. 61-64; Reply filed on August
21, 2006). The Patent Owner also asserts that “[i]t is hard to conceive that
tang structures embedded well within a cutting head were designed for
ornamental purposes” (Patent Owner’s Rebuttal Brief filed August 12, 2009
at 4).
Thus, the issues in this appeal are:
(1) Did the Examiner err in finding that the rounded ends of the
bell-shaped tangs recited in claim 1 serve an ornamental purpose?
(2) Did the Examiner articulate a reason based on some rational
underpinning sufficient to support a conclusion that it would have been
obvious to a person of ordinary skill in the art to combine the references in
the manner claimed?

FINDINGS OF FACT (“FF”)
1. The ‘874 Patent discusses Proulx ‘782 (the prior art reference
applied in the rejections as the closest prior art) in the context of
a device over which the invention of the ‘874 Patent is an
improvement (col. 1, l. 20 to col. 2, l. 60).
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2. Figure 3 (Prior Art) of the ‘874 Patent, which is identical to
Figure 10 of Proulx ‘782, is reproduced below:

Figure 3 (Prior Art) of the’874 Patent depicts an exploded view
of the flail feedout assembly disclosed in Proulx ‘782, wherein
the assembly includes: follower member 218 with upwardly
facing tangs 222 and knobs 214, 216; a cam member 228 with
generally rectangular tangs 236, which in concert with vertical
abutment 232, define a serpentinous cam groove 224; and a
spool assembly with grooves 200, 202 and cutouts 210 and 212
above a bumper 44’ (‘874 Patent at col. 3, l. 30 to col. 4, l. 10;
Proulx ‘782 at col. 4, l. 50 to col. 5, l. 50).
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3. The ‘874 Patent describes the operation of the prior art device
of Proulx ‘782 as follows (‘874 Patent at col. 3, l. 32 to col. 4, l.
2; Proulx ‘782 at col. 5, ll. 7-50):
[W]hen the bumper 44’ is bounced or
momentarily pressed on the ground, knobs 214 and
216 are forced out of the cutouts 210 or 212,
wherein they are retained against the force of
spring 82’ [not shown in Figure 3 above] to hold
the spool in the assembly, and knobs 214 and 216
ride upwardly in the grooves 200 and 202 against
the force of the biasing spring 82’. The latter
presses downwardly on the upper surface 220 of a
follower member 218. Rotation of the spool
assembly 42’ is slowed or stopped during the
bounce or pressing of the bumper 44’ against the
ground to allow line to feed out. When the bumper
44’ is no longer pressed against the ground, the
knobs 214, 216 are spring-urged back into cutouts
210, 212 to again retain the spool . . . .
Follower member 218 also includes four
uniformly spaced upwardly facing tangs 222
adjacent the upper surface 220 of the follower
member 218. The position and spacing of the
tangs 222 determine, in part, the amount of
filament segment 20’ released per filament release
cycle when the bumper 44’ is bounced or
momentarily pressed on the ground. The tangs
222 ride in a serpentinous cam groove 224 formed
adjacent the upper surface 226 of a cam member
228 . . . [T]he tangs 222 are restricted to motion
within the cam groove 234 and, depending upon
the rotational direction of the spool 24’, the tangs
222 move from one adjacent vertical surface 232
to the next facing vertical surface in the same
direction.
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4. Relative to the prior art device disclosed in Proulx ‘782, the
‘874 Patent states that “[t]he configuration of the subject
invention results in better force distribution and the reduction of
stress concentrations when the tangs and prongs engage each
other, thereby resulting in a smoother feedout of the filament
and a structurally enhanced feedout assembly” (col. 2, ll. 52-
56).
5. Figure 4 (within the scope of the claimed invention) of the ‘874
Patent Specification is reproduced below:

Figure 4 of the ‘874 Patent depicts an exploded view of a flail
feedout assembly 300 for use in the claimed cutting head,
wherein the assembly includes: a follower member 302 with
upwardly facing bell-shaped tangs 308 and knobs 312; a cam
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member 304 with bell-shaped tangs 334, which in concert with
vertical abutment 330, define a serpentinous cam groove 324;
and a spool member with grooves 350 and 352 and lateral
cutout 358 (col. 3, ll. 3-4; col. 4, l. 11 to col. 5, l. 27).
6. The ‘874 Patent Specification identifies the key difference
between the claimed subject matter and Proulx ‘782 as follows
(col. 4, ll. 61-67):
[I]nstead of being generally rectangular in plan
form, as illustrated in FIG. 5D, each tang is of a
truncated, bell-shaped configuration and thus is
defined by multiple radiuses. As a result, each
tang 308, 334 is configured to avoid stress
concentrations upon impact of the cam member
and the follower member during a flail feedout
operation.
7. Figures 4-6 of Proulx ‘419 are reproduced below:

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Figures 4-6 of Proulx ‘419 depict a flail feedout mechanism in
which four-sided cams 124 and 136 provide, in essence,
triangular tangs that interact with relief surfaces on cam
follower 86 (col. 5, ll. 32-60).
8. Proulx ‘419 teaches that “since large abutment surface areas are
presented between the cams and the cam follower, the device is
extremely robust, trouble-free and reliable” and that the
“engagement surfaces have a relatively large contact area to
reduce the pressure applied thereto” (col. 2, ll. 61-64; col. 3, ll.
7-10).
9. Elements of Strength of Materials (incomplete excerpt) appears
to teach that, in the case of a plate having two portions of
different widths, the maximum stress occurs at the junction or
shoulder where the two portions meet and that it is customary
“to specify a minimum radius of fillet to prevent the
development of progressive cracks at reentrant corners” (p. 24).
10. Strength of Materials Part II: Advanced Theory and Problems
(incomplete excerpt) appears to teach that stress concentrations
in (e.g., nut and bolt) may be relieved “considerably by
eliminating sharp reentrant corners and introducing fillets of
generous radius, by designing fillets of proper shape, by
introducing relieving grooves, etc.” (pp. 498-99).
11. Tomita teaches that stress concentration in a turbine blade may
be suppressed by providing a fillet made to an elliptical curve (¶
0056).
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12. Takemura discloses a metal-bonded drilling and boring tool in
which the tool has a connecting portion connecting a rod-
shaped body to an enlarged mounting portion that has a smooth
concave portion to suppress stress concentration occurring at
the rod-shaped body (¶ 0070; Fig. 12).
13. The Balaban Declaration reveals that Dr. Balaban is not a
person of ordinary skill in the art of cutting heads or flail
feedout mechanisms for rotary trimmers (Balaban Decl. ¶ 2).
14. Notwithstanding the teachings of Elements of Strength of
Materials, Strength of Materials Part II: Advanced Theory and
Problems, Tomita, and Takemura, Dr. Balaban testifies that
“[r]adiusing the vertices of the tangs as well as their bases to
provide the ‘truncated bell-shaped configuration’ does not
minimize stress concentrations as claimed” and that “stress
concentrations will be unaffected by radius changes at the tang
vertices” (Balaban Decl. ¶¶ 15-17; emphases added).
15. Dr. Balaban further acknowledges that the triangular tangs of
Proulx ‘419 “increased the contact area of the cam member
tangs and eliminated any stress points on the cam member
tangs” (Balaban Decl. ¶ 23; emphasis added).
16. Mr. Proulx states that he is the President of Proulx
Manufacturing, Inc. (Requester) (Proulx Decl. ¶ 1).
17. Mr. Proulx testifies that the “over-engineered for strength”
trimmer of Proulx ‘419 “has not had a single complaint from an
OEM” and that “there are no internal corners where stress
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might be concentrated as would be the case with a radially
projecting tang” (Proulx Decl. ¶¶ 4, 6).
18. Mr. Proulx emphasizes that he “can unequivocally state that
stress concentrations are not and never have been an issue with”
the trimmer heads disclosed in Proulx ‘419 (Proulx Decl. ¶ 6).

PRINCIPLES OF LAW
The Supreme Court of the United States explained that “a patent
composed of several elements is not proved obvious merely by
demonstrating that each of its elements was, independently, known in the
prior art.” KSR Int’l v. Teleflex, Inc., 550 U.S. 398, 418 (2007). “Although
common sense directs one to look with care at a patent application that
claims . . . the combination of two known devices according to their
established functions, it can be important to identify a reason that would
have prompted a person of ordinary skill . . . to combine the elements in the
way the claimed new invention does.” Id. While the Supreme Court
warned against “[r]igid preventative rules that deny factfinders recourse to
common sense,” it stated that the “factfinder should be aware . . . of the
distortion caused by hindsight bias and must be cautious of arguments reliant
upon ex post reasoning.” Id. at 421.
The initial burden of establishing a prima facie case of unpatentability
rests on the Examiner. In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992).

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ANALYSIS
As stated above, the Examiner’s basic position is that the substitution
of the generally-rectangular tangs of Proulx ‘782 with the triangular tangs of
Proulx ‘419, followed by further modification of the resulting device with
fillets (as shown in Tomita, Takemura, and the two textbook references) and
truncation of the vertices to arrive at tangs with a “truncated, bell-shaped
configuration,” would have been obvious to a person of ordinary skill in the
art (Ans. 5, 10, 12; FF 1-12).
We must agree with the Patent Owner that the Examiner’s rejections
are not well founded. For one thing, the Examiner has not directed us to any
credible evidence in support of obviousness that a person of ordinary skill in
the art would have truncated and rounded the triangular tangs of Proulx ‘419
for ornamental purposes.
Moreover, as pointed out by the Patent Owner, “there is no suggestion
or teaching in either of the publication references to provide fillets to the
hypothetical, tapered tang structure which the Examiner created, in a
vegetation trimmer environment where the contacting tangs violently engage
each other” (App. Br. 19-21).2 Specifically, although explicit suggestion or
teaching need not be found in the reference relied upon, the Examiner has
not directed us to any persuasive evidence that a person of ordinary skill in
the art would have perceived any need to address a stress problem when the
tangs of Proulx ‘782 are substituted with the tangs of Proulx ‘419, which are

2 The same or similar argument is made against Tomita and Takemura (App.
Br. 23-24).
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already provided with “engagement surfaces [that] have a relatively large
contact area to reduce the pressure applied thereto” (FF 8).
The theory that a person of ordinary skill in the art would have further
modified the combination of Proulx ‘782 and Proulx ‘419 in view of the
other references is severely undercut by the Examiner’s own relied-upon
evidence and factual findings. The Requester’s expert, Dr. Balaban, testified
that the “truncated, bell-shaped configuration” recited in the claims would
not reduce stress concentrations (FF 14). Similarly, Mr. Proulx, Requester’s
President, stated that the device of Proulx ‘419 was “over-engineered for
strength” and “that stress concentrations are not and never have been an
issue” (FF 17-18). The Examiner, too, found that “rounding of the free ends
[of the tangs]” would not result in the “avoidance of stress concentrations”
(Ans. 5). These facts directly contradict the Examiner’s obviousness
conclusion that it would have been obvious to a person of ordinary skill in
the art to further modify the triangular tangs of Proulx ‘419 and/or the
generally rectangular tangs of Proulx ‘782 to a “truncated, bell-shaped
configuration” in view of the applied prior art references to reduce stress
concentrations.
Given these contradictions in the Examiner’s own factual findings and
relied-upon evidence in support of the obviousness conclusion, we must
agree with the Patent Owner that the rejections are based on impermissible
hindsight reconstruction.

CONCLUSION
On this record,
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(1) the Examiner erred in finding that the rounded ends of the bell-
shaped tangs recited in claim 1 serve an ornamental purpose, and
(2) the Examiner failed to articulate a reason based on some
rational underpinning sufficient to support a conclusion that it would have
been obvious to a person of ordinary skill in the art to combine the
references in the manner claimed.

DECISION
The Examiner’s decision to reject claims 1-6 is reversed.
REVERSED

saw

FOR PATENT OWNER:
HESPOS & PORCO LLP
110 WEST 40TH STREET
SUITE 2501
NEW YORK, NY 10018

FOR THIRD-PARTY REQUESTER:
RICHARD E. LYON, JR.
HOLLAND & KNIGHT LLP
633 WEST FIFTH STREET 21ST FLOOR
LOS ANGELES, CA 90071-2040