9254865 et al.

Patent Trials and Appeals Board

Mar 26, 2020

90013980 - (D) (P.T.A.B. Mar. 26, 2020)

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.
90/013,980 07/12/2017 9254865 MTD-865Reexam 9011
32425 7590 03/26/2020
NORTON ROSE FULBRIGHT US LLP
98 SAN JACINTO BOULEVARD
SUITE 1100
AUSTIN, TX 78701-4255
EXAMINER
ENGLISH, PETER C
ART UNIT PAPER NUMBER
3993
MAIL DATE DELIVERY MODE
03/26/2020 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 PATENT TRIAL AND APPEAL BOARD
Ex parte MTD PRODUCTS INC.
Patent Owner and Appellant

Appeal 2019-001226
Reexamination Control 90/013,980
Patent 9,254,865 B21
Technology Center 3900
BEFORE DANIEL S. SONG, MEREDITH C. PETRAVICK, and
WILLIAM V. SAINDON, Administrative Patent Judges.
SONG, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(b) and 306, the Patent Owner2 appeals
from the final rejection of claims 1–20. We have jurisdiction under
35 U.S.C. § 6(b).
We are informed that the ’865 Patent was involved in a litigation,
which has been dismissed with prejudice due to settlement, and also was the

1 Issued February 9, 2016 to Schaedler et al. (“the ’865 Patent”).
2 The real party in interest as MTD Products Inc. Appeal Br. 1.
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

2
subject of a request for Inter Partes Review for which the Board denied
institution. Appeal Br. 1. In addition to its Appeal Brief and Reply Brief,
the Appellant also relies on two declarations of Dr. Charles Reinholtz filed
on January 22, 2018 (“Reinholtz Decl. 1”) and April 9, 2018 (“Reinholtz
Decl. 2”) in support of patentability.
We AFFIRM.
THE INVENTION
The ’865 Patent is directed to a steering system. Title. In particular,
the patent is directed to the steering systems for Zero Turn Radius (“ZTR”)
vehicles, such as a lawn and garden tractor. Spec. col. 1, ll. 22–24; col. 6, ll.
41–46. There is a known angular relationship for front steering wheels to
obtain a given turn radius without causing the wheels slide or scuff, referred
to as Ackermann3 steering geometry. Spec. col. 7, l. 61–col. 8, l. 10.
Figures 3A and 3B of the ’865 Patent show the steering angles for a tight
right turn (3A) and a zero radius turn (3B):

3 Ackermann steering geometry is represented by the following
mathematical relationship:

where θo is the turn angle of the outside wheel; θi is the turn angle of the
inside wheel; “w” is the vehicle track width; and “l” is the vehicle
wheelbase.
Reinholtz Decl. 1 ¶¶ 30–31.
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

3

Figure 3A depicts the angles of the front wheels of a vehicle making a
tight right hand turn around a center point C. Figure 3B depicts the vehicle
making a zero radius turn around center point C.
The ’865 Patent discloses that:
When front wheels 18 make the turn depicted in FIG. 3A, they
take two distinct arc-like paths P i and Po, which ideally will have
a common center point C located along the axis that extends
through the center of both drive wheels 16. Lines Li and Lo
extend from center point C and intersect the paths P i and Po,
respectively, of the two wheels at the rotational centers of the
wheels. The use of a substantially-true Ackermann steering
geometry . . . can help to avoid scrubbing rubber from the tire
tread on the outboard wheel or damaging vegetation under the
front wheels.
Spec. col. 7, l. 67–col. 8, l. 10.
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

4
To implement such steering, the ’865 Patent discloses the use of non-
circular gears that attain non-uniform gear ratios. Spec. col. 11, ll. 12–16;
col. 11, l. 59–col. 12, l. 1; Figs 8A–8C.
CLAIMED SUBJECT MATTER
The claims are directed to a steering system. Claim 1, reproduced
below, is illustrative of the claimed subject matter:
l. A vehicle comprising:
a chassis;
a left front steerable, non-driving wheel coupled to the
chassis and capable of turning more than 90 degrees left;
a right front steerable, non-driving wheel coupled to the
chassis and capable of turning more than 90 degrees right;
left and right rear drivable wheels coupled to left and right
hydrostatic drive units;
a first gear pair that turns the right front steerable, non-
driving wheel, the first gear pair comprising:
a first wheel gear having a first wheel gear pivot
axis and a first wheel gear pitch line that changes in
distance from the first wheel gear pivot axis; and
a first steering gear engaged with the first wheel
gear, the first steering gear having a first steering gear
pivot axis and a first steering gear pitch line that changes
in distance from the first steering gear pivot axis;
a second gear pair that turns the left front steerable, non-
driving wheel, the second gear pair comprising:
a second wheel gear having a second wheel gear
pivot axis and a second wheel gear pitch line that changes
in distance from the second wheel gear pivot axis; and
a second steering gear engaged with the second
wheel gear, the second steering gear having a second
steering gear pivot axis and a second steering gear pitch
line that changes in distance from the second steering gear
pivot axis;
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

5
a steering wheel that can receive a steering input from an
operator of the vehicle;
a speed pedal that can receive a speed input from an
operator of the vehicle;
first and second speed cams oriented parallel to each other
and coupled to the speed pedal, the first speed cam including a
first curved slot and the second speed cam including a second
curved slot, the first and second curved slots having the same
shape, where movement of the speed pedal causes the first and
second speed cams to rotate in the same direction and by the
same amount about an axis extending through each of the first
and second curved slots;
a first follower that rides in the first curved slot and that
will move in response to steering wheel movement to a right-
hand turn from a straight-ahead position; and
a second follower that rides in the second curved slot and
that will move in response to steering wheel movement to a left-
hand turn from a straight-ahead position;
where the left and right hydrostatic drive units are capable
of driving the left and right rear drivable wheels at different
speeds and in different directions; movement of the steering
wheel without a speed input from the speed pedal does not cause
rotation of the left and right rear drivable wheels; and the same
one of the left and right rear drivable wheels will rotate faster
than the other of the left and right rear drivable wheels in both
forward and reverse for a turned position of the steering wheel.
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

6
REFERENCE(S)
The prior art relied upon by the Examiner is:
Name Reference Date
Claude 1,748,061 Feb. 25, 1930
Paramythioti 3,550,708 Dec. 29, 1970
Hauser US 6,962,219 B2 Nov. 8, 2005
Hauser4 US 2003/0102171 A1 June 5, 2003
Irikura US 2003/0106725 A1 June 12, 2003
Barnes GB 2 303 829 A Mar. 5, 1997
LazerZ Exmark Mfg. Co. Inc.
LazerZ Brochure
1995
REJECTIONS
The Examiner rejects various claims under pre-AIA 35 U.S.C.
§ 103(a) as follows:
1. Claims 1–10 as unpatentable over Hauser in view of Irikura,
Claude, and Barnes. Final Act. 4.
2. Claims 11–20 as unpatentable over Hauser in view of Irikura,
Claude, Barnes, and LaserZ. Final Act. 12.

4 The Examiner observes that:
Hauser ’171 is the pre-grant publication of the
application that later issued as Hauser ’219. Accordingly,
Hauser ’171 contains the same disclosure as Hauser ’219.
However, Hauser ’171 qualifies as prior art under pre-AIA 35
USC 102(b) with respect to the claims of Patent No. 9,254,865
whereas Hauser ’219 qualifies as prior art under pre-AIA 35
USC 102(e).
Final Act. 6.
The Appellant simply refers to these references as “Hauser.” Appeal
Br. 4. Accordingly, we also refer to these references herein as “Hauser.”
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

7
3. Claims 16–20 as unpatentable over Hauser in view of Irikura,
Claude, Barnes, LaserZ, and Paramythioti. Final Act. 13.
OPINION
Only those arguments actually made by Appellant have been
considered in this decision. Arguments which Appellant could have made
but chose not to make in the Brief have not been considered and are deemed
to be waived. See 37 C.F.R. § 41.37(c)(1)(iv); see also In re Jung, 637 F.3d
1356, 1365 (Fed. Cir. 2011) (“it has long been the Board’s practice to
require an applicant to identify the alleged error in the examiner’s
rejections”); Ex Parte Frye, 94 USPQ2d 1072, 1075–76 (BPAI 2010,
precedential). In addition, although the declarations of Dr. Reinholtz have
been fully considered, we omit citations to the declarations when citing to
the Appeal Brief that cites or quotes the declarations.

Rejection 1: Hauser, Irikura, Claude, and Barnes
The Examiner finds that Hauser discloses the invention substantially
as recited in independent claims 1, 11, and 16, but finds that Hauser fails to
disclose “a steering system having first and second gear pairs with a variable
gear pitch line (claims 1 and 11) or non-uniform gear ratio (claim 16).”
Final Act. 4–6. Indeed, Hauser fails to disclose a specific steering system
for the steerable front wheels.
The Examiner correctly finds that Irikura discloses:
a zero turn radius (ZTR) steering system including first and
second gear pairs 101R, 101L on opposite sides of the vehicle,
with each gear pair 101R, 101L comprising: a wheel gear 59 . .
. and a steering gear 58 engaged with the wheel gear 59 . . .
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

8
wherein each of the wheel gears 59 and the steering gears 58
has a gear pitch line that has different distances from its
respective pivot axis at different locations along the pitch line,
i.e., having a variable gear pitch line providing a non-uniform
gear ratio.
Final Act. 6–7, citing Irikura, Figs. 36 and 41–44; ¶¶ 131–134, 138, 140,
176–182.
The Examiner also correctly finds that Irikura “specifically teaches
that [the disclosed] steering geometry prevents transverse slipping (i.e., tire
scrub or wheel skid) of the steerable wheels 41R, 41L.” Final Act. 7, citing
Irikura ¶¶ 189, 196.
The Examiner further finds that Claude discloses that designing a
steering system satisfying the Ackermann equation was known, teaches a
differential cam equation, and discloses a steering system that requires “at
least one of steering cams [be] formed with a variable pitch line providing a
non-uniform (differential) steering ratio.” Final Act. 7, citing Claude, Fig. 2;
pg. 1, l. 33–pg. 2, l. 18; pg. 2, l. 127. In that regard, the Examiner also finds
that Claude discloses an intermediate cam disc with variable pitch for
driving the steering cam. Final Act. 7–8, citing Claude, pg. 1, l. 98–pg. 2, l.
2.
The Examiner concludes that:
Therefore, both Irikura ’725 and Claude teach steering
systems having first and second gear/cam pairs with a variable
gear/cam pitch line (claims 1 and 11) or non-uniform gear/cam
ratio (claim 16). From these teachings of Irikura ’725 and
Claude, it would have been obvious to one of ordinary skill in
the art at the time the invention was made to modify Hauser . . .
by providing the steering system with first and second gear
pairs with a variable gear pitch line (claims 1 and 11) or non-
uniform gear ratio (claim 16) because such a steering system
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

9
provides the advantage of optimal steering as a result of
location of the steerable wheels on tangents of concentric
circles having their common center coincident with the
rotational axis of the rear drive wheels. Further, such a
modification is obvious because it involves the mere
combination of one known type of steering system taught by
Irikura ’725 and Claude with the vehicle of Hauser . . .
according to known methods, yielding only a predictable result.
Final Act. 9–10.
The Examiner further finds that Hauser also fails to “teach speed cams
provided with curved slots such that movement of the steering wheel without
a speed input from the speed control member does not cause rotation of the
left and right drivable wheels.” Final Act. 10. However, the Examiner finds
that Barnes teaches a ZTR steering system having speed cams with arcuate
slots that receive followers, and concludes that provision of such speed cams
would have been obvious to one of ordinary skill in the art. Final Act. 10–
11, citing Barnes, Figs. 1–5 and disclosures pertaining thereto.
The Patent Owner does not contest that the references describe each
limitation of the claims. Instead, the Patent Owner attacks the Examiner’s
combination of Hauser, Irikura, and Claude, as discussed infra.

Prima Facie Case of Obviousness
The Patent Owner initially argues that “the Office has not satisfied its
burden to produce a prima facie case of obviousness because it does not
explain how or why a POSITA[5] would have arrived at the Irikura/Claude
steering system.” App. Br. 18; see also App. Br. 19. According to the

5 That is, a person of ordinary skill in the art.
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

10
Patent Owner, “despite recognizing that Irikura ’725’s steering system is
gear-based and Claude’s steering system is cam-based, the Office has not
explained how or why a POSITA would have applied Claude’s cam-based
teachings to Irikura’s gear-based teachings or vice-versa,” and that it “must
guess at the meaning of the Irikura/Claude steering system” and whether
Irikura’s steering gear units are being modified or Claude’s steering cams
and cam disc are being modified to be gears. App. Br. 20.
We disagree with the Patent Owner, and find the rejection as set forth
above provides sufficient notice to the Patent Owner and the Board as to the
basis of how these references are being applied in the present rejection. See
35 U.S.C. § 132(a); 37 C.F.R. § 1.104(a)(2), (c)(2). The Examiner has relied
on Irikura for its disclosure of a zero turn radius (“ZTR”) steering system
utilizing gear pairs that have variable gear pitch line that provides a non-
uniform gear ratio to prevent transverse-slipping of the wheels. Final Act.
6–7. The Examiner has also relied on Claude to establish that a steering
system having variable pitch for providing Ackermann steering was known
in the art. Final Act. 7–8. The Examiner further explained that “it would
have been obvious to one of ordinary skill in the art at the time the invention
was made to modify Hauser . . . by providing the steering system with first
and second gear pairs with a variable gear pitch line . . . or non-uniform gear
ratio.” Final Act. 10.
Thus, the Examiner has made it sufficiently clear that mower of
Hauser is being modified to include a steering system with Irikura’s non-
uniform ratio gear pairs, and is concluding that any modification required to
the gear pairs to attain substantially Ackermann steering would have been
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

11
obvious and within the skill of a person of ordinary skill in the art in view of
Claude. See also Final Act. 7–8. The rejection relies on Claude for
evidence that Ackermann steering system was known, and that providing
variable ratios/pitch line along the interface of the system components, i.e.,
the cams to provide such steering was also known, such that to any extent
Irikura’s gear pairs do not provide substantially Ackermann steering in view
of the lack of explicit reference to Ackermann or its representative equation,
it would have been obvious and within the skill of those of ordinary skill in
the art to modify the gear pairs accordingly to achieve substantially
Ackermann steering. The Patent Owner appears to require the Examiner to
set forth the specific manner in which the structure of Claude can be bodily
incorporated into the non-uniform ratio gear pairs of Irikura, but does not
fully consider what Claude was cited for. The Examiner does not propose to
incorporate physical components from Claude; rather the Examiner cites
Claude as evidence of what a person of ordinary skill in the art would know.
In view of the above considerations, we find the rejection sufficiently
clear in setting forth a prima facie case of obviousness, and we are not
persuaded by the Patent Owner’s arguments to the contrary.

Hauser
There is no dispute between the Patent Owner and the Examiner as to
the educational background, training, and experience of a person of ordinary
skill in the art. See Reinholtz Decl. 1 ¶¶ 13–15. However, what would have
been obvious to the person of ordinary skill in the art underlies the
substantive arguments of the Patent Owner as discussed infra.
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

12
The Patent Owner asserts that a person of ordinary skill in the art
would have been familiar with Ackermann steering and its importance for
mowers like that disclosed in Hauser because wheel-slip will damage lawns.
App. Br. 26. The Patent Owner also asserts that “Hauser specifies an
Ackermann steering system” (App. Br. 18; see also, e.g., App. Br. 29), and
the declarant testifies that Hauser “calls for” and “requires” Ackerman
steering. See Reinholtz Decl. 1 ¶¶ 17, 37. Based thereon, the Patent Owner
argues that a person of ordinary skill in the art “would have avoided using a
non-Ackermann steering system in a mower like Hauser’s because non-
Ackermann steering systems produce lawn-damaging wheel slip, which was
acutely unacceptable to a POSITA.” App. Br. 18. According to the
declarant, any steering system that is not an Ackerman system would not be
used by a person of ordinary skill because it would be “sub-optimal” and
“wheel slip caused by a non-Ackermann steering system would be
unacceptable.” Reinholtz Decl. 1 ¶¶ 17–18,
The basis for the Patent Owner and the declarant’s assertions as to
Hauser is its teaching that:
Any manner of steering the front wheels 4, 5 may be chosen with
sound engineering judgment. In this way, the front steerable
wheels 4, 5 may be rotated to be substantially tangent to an arc
defined at one point by the radius of turning and by the other
point at the center of each wheel 4, 5.
Hauser, col. 6, ll. 21–26.
The Examiner generally agrees with the Patent Owner “with major
exception,” which is that Hauser “use[s] the qualifier ‘substantially’ . . . and,
therefore, POSITA would understand that these references call for a steering
geometry for the front steerable wheels 4, 5 that ‘substantially’ satisfies the
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

13
Ackermann equation.” Ans. 14. According to the Examiner, such a
qualifier also evinces that a person of ordinary skill “would also understand
that the Ackermann equation is theoretical and difficult to fully satisfy in
reality.” Ans. 14–15.
We generally agree with the Examiner’s assessment, and we find the
Patent Owner and declarant reads too much into the above-reproduced
passage of Hauser. Although Hauser’s disclosure can reasonably
characterized as teaching the desirability of, or “call[ing] for,” an
Ackermann steering, it does not mandate or require strict adherence thereto
at the exclusion of all other types of steering systems. Indeed, Hauser
specifies that “[a]ny manner of steering the front wheels 4, 5 may be chosen
with sound engineering judgment.” Hauser, col. 6, ll. 21–22. In whole, the
Patent Owner’s over-reading of this passage in Hauser negatively impacts
their arguments discussed infra.

Obviousness in view of Irikura and Claude
As noted above, Irikura explicitly discloses gear pairs having non-
uniform gear ratio to allow “the centers of the lateral turning circles of
wheels 41L and 41R, whose radii are extended axes of respective wheels 41,
[to] coincide with the turning center of the vehicle,” and prevent “transverse-
slipping.” Irikura ¶¶ 176, 189; Figs. 36 and 41–44. Claude discloses a
steering system with cams having a variable pitch line for satisfying the
Ackermann equation as well as a derivative equation. Claude, Fig. 2; pg. 1,
l. 33–70.
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

14
Contrary to these explicit teachings, the Patent Owner argues that “a
POSITA would have understood that a gear-based steering system produced
according to the teachings of Irikura ’725, if used in Hauser’s mower, would
cause misalignment of the mower’s wheels,” which would result in “lawn-
damaging wheel slip––rendering the mower unsuitable for use as a mower––
but also frustrates the mower’s ability to approach and perform a zero-radius
turn––rendering the mower unsuitable as a zero-turn vehicle.” App. Br. 24–
25; see also App. Br. 39, 52. The Patent Owner relies on the first
declaration of Dr. Reinholtz in support, which states that:
The steering system described in [Irikura ’725] is not an
Ackermann steering system. Irikura ’725, at first glance,
purports to provide Ackermann steering. However, after
reviewing Irikura ’725’s disclosure, it is readily apparent that
Irikura ’725’s steering system fails to provide the promised
Ackermann functionality. Rather, a mower using Irikura ’725’s
steering system would exhibit considerably more wheel slip
than if it used an Ackermann system.
Reinholtz Decl. 1 ¶ 28.
The declarant utilizes trigonometry and calculus to mathematically
determine the derivative of the Ackermann equation6 and graphs the result
for several values of the ratio of vehicle track width and wheelbase (w/l) to
show that the derivative of the Ackermann equation increases, peaks, and
then decreases. Reinholtz Decl. 1 ¶¶ 30–36. The declarant points to Figures
36 and 40 of Irikura and its disclosure that the gear ratio “reduce[s] the rate

6 Dr. Reinholtz calculates the derivative equation of the Ackermann equation
to be:

Reinholtz Decl. 1 ¶ 33.
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

15
of increase of lateral turning angle of the outside wheel 41” and “increas[es]
the rate of lateral turning angle of inside wheel 51” to conclude that Irikura
does not satisfy the derivative equation of the Ackermann equation because
the derivative of Irikura continuously increases as steering input increases.
Reinholtz Decl. 1 ¶¶ 39–55.
The Patent Owner also relies on Dr. Reinholtz’s second declaration to
argue that a person of ordinary skill “would not and could not have arrived
at the Irikura/Claude steering system because cams or gears shaped to satisfy
Claude’s differential cam equation [sin α : sin β = x : y] and the Ackermann
equation are physically impossible.” App. Br. 61 (formatting removed).
The declarant uses Claude’s relational expression as an equation, the
calculated derivative equation of the Ackermann equation, and other
mathematical equations derived by applying algebra, trigonometry, and
calculus, to solve Claude’s differential cam equation using selected values
for the variables to conclude that the cams would have to have “a radius that
is larger than the distance between its pivot point and the pivot point of its
driving cam,” which is impossible. Reinholtz Decl. 2 ¶ 31; see also
Reinholtz Decl. 2 ¶¶ 5–9, 11, 12, 16, 17, 23, 27–35; App. Br. 25, 72.
The Patent Owner further argues that Claude’s teachings do not
provide a person of ordinary skill in the art guidance to build a steering
system suitable for Hauser’s mower because Irikura uses gears while Claude
uses cams, which are “distinct mechanical elements that are not simply
interchangeable” such that a person of ordinary skill would have viewed
“Claude’s teachings of the radii of cams, having smooth peripheries, as
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

16
inapplicable to gears with their toothed peripheries.” App. Br. 83–84,
quoting Reinholtz Decl. 2 ¶ 15.
Based on the above, the Patent Owner argues that “a POSITA would
not have modified Hauser to include the Irikura/Claude steering system’s
‘first and second gear pairs with a variable pitch line”’ (App. Br. 25), and
that the “proposed combination would have rendered Hauser’s mower
unsatisfactory for its intended purpose.” App. Br. 18. Indeed, the declarant
testifies that reviewing Irikura “inevitably would have led a POSITA to
abandon any thoughts they had about using Irikura ’725’s steering system in
Hauser’s mower.” Reinholtz Decl. 1 ¶ 29. Similar testimony is provided
with respect to Claude. Reinholtz Decl. 2 ¶ 32. The Patent Owner further
argues that it would have required “a redesign of Irikura[]’s steering
system,” and “[s]uch a redesign would have been tantamount to the design––
from scratch––of a gear-based Ackermann steering system capable of
performing a zero-radius turn, which was beyond the skill possessed by a
POSITA.” App. Br. 83, citing Reinholtz Decl. 1 ¶¶ 63–66.
We do not find these arguments of the Patent Owner persuasive. We
agree with the Examiner that “[t]he declarant contradicts the explicit
disclosure of Irikura,” which “explicitly teaches that the steering system
satisfies (or at least very closely approximates) the Ackermann equation.”
Ans. 15. We agree with, and adopt as our own, the Examiner’s finding that:
Irikura ’725 explicitly teaches that: (a) the steerable wheels 41R, 41L
are moved by the wheel gears 59 into tangential relation to concentric
circles having their common center 196 upon a line of centers 199
coincident with the rotational axis of the rear drive wheels 43R, 43L
of the vehicle (see Figs. 42–44; ¶¶ 0185–0196); (b) such a steering
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

17
geometry prevents transverse slipping (i.e., tire scrub or wheel skid)
of the steerable wheels 41R, 41L (see ¶¶ 0189, 196).
Ans. 15.
We are not persuaded by Dr. Reinholtz’s testimony that a person of
ordinary skill would not have found it obvious to modify the mower of
Hauser to include a steering system having gear pairs with non-uniform gear
ratio like that disclosed in Irikura. Hauser does not provide disclosure of a
steering system for its mower. Thus, in view of the absence of a steering
system for its mower, it would have been obvious to a person of ordinary
skill in the art to have implemented for Hauser’s mower, a steering system
such as that of Irikura, which is disclosed as providing the functionality
generally suggested by Hauser, via gear pairs having non-uniform gear ratio
that allow “the centers of the lateral turning circles of wheels 41L and 41R,
whose radii are extended axes of respective wheels 41, [to] coincide with the
turning center of the vehicle,” and prevent “transverse-slipping.” Irikura ¶¶
176, 189. In this way, Irikura provides a specific steering solution meeting
the characteristics of a steering system called for by Hauser. Hauser, col. 6,
ll. 21–26 (calling for a steering system chosen with “sound engineering
judgment” that includes features such as keeping the front wheels tangent to
an arc defined by the radius of turning).
The Patent Owner and the Examiner further disagree as to whether Dr.
Reinholtz’s mathematical analysis based on the derivative equation of the
Ackermann equation is required for an Ackermann steering system. The
Patent Owner argues that because the derivative equation is “the derivative
of the Ackermann equation,” it must be satisfied to be an Ackermann
steering system, and because Irikura does not satisfy it, the steering system
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

18
of Irikura is not an Ackermann steering system. App. Br. 35, 39–48. The
Examiner responds that “the declarant seeks to add a further requirement” to
what is considered to be an Ackermann steering by requiring satisfaction of
the derivative equation, but “fails to provide any independent corroboration
(e.g., a printed publication such as Wong7) showing that this relationship is,
in fact, required.” Ans. 16; see also Ans. 19. The Examiner and the Patent
Owner/declarant further disagree as to whether the derivative equation is
merely pertinent to the steering shown in Figure 3B of the’865 Patent in
which the wheels follow the same arc, which is not the case in Irikura. Ans.
17; Reinholtz Decl. 2 ¶ 26.
We do not find this dispute regarding the derivative of the Ackermann
equation and its relevance to Irikura to be dispositive for the reasons
discussed infra, but nonetheless, find the Examiner’s position more
persuasive. The evidence of record indicates that to be considered an
Ackermann steering system in the art, it must satisfy a geometric equation.
Reinholtz Decl. 1 ¶¶ 30–31; Claude, pg. 1, ll. 33–35; Wong, pgs. 336, 337.
There is no indication except for the assertions of the declarant that the
derivative equation must also be satisfied in order for a suspension system to
be considered an Ackermann steering system in the art.
Regardless of the above, even if Irikura fails to satisfy perfectly the
derivative equation, and thus, is incapable of providing perfect Ackerman
steering as Dr. Reinholtz attests, the Patent Owner’s arguments presume that
Hauser mandates a perfect Ackermann steering system. As discussed above,

7 Wong, Theory of Ground Vehicles, 3rd Ed. (2001), pg. 336, 337. Final
Act. 3.
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

19
the passage of Hauser relied upon by the Patent Owner suggests the
desirability of an Ackermann steering system, but it does not mandate or
require strict adherence thereto at the exclusion of all other types of steering
systems. Thus, the Patent Owner’s assertion that the combination of Houser
and Irikura would not be made is premised on the incorrect assertion that
Hauser mandates an Ackermann steering system at the exclusion of all other
steering systems, and that systems providing imperfect steering cannot be
used. In that regard, we generally agree with the Examiner that “[e]ven if
Irikura ’725 is incapable of providing complete Ackermann functionality, it
nevertheless fulfills the lesser call of Hauser . . . for a steering geometry that
‘substantially’ satisfies the Ackermann equation.” Ans. 16.
The Patent Owner’s arguments against Claude stand on similar
footing. As the Examiner responds, “[t]he declarant contradicts the explicit
disclosure of Claude,” which “discloses an improved steering system
including steering cams providing for pure rolling movement of the steered
wheels” to avoid wheel skid, and at least substantially satisfies the
Ackermann equation. Ans. 18, citing Claude p. l, ll. 1–5, 33–81. Similar to
Irikura, we further agree with the Examiner that “[e]ven if Claude is
incapable of providing complete Ackermann functionality, it nevertheless
fulfills the lesser call of Hauser ’219 or Hauser ’171 for a steering geometry
that ‘substantially’ satisfies the Ackermann equation.” Ans. 18.
As to the Patent Owner’s arguments based on Claude’s use of cams in
contrast to Irikura’s use of gears, we find this argument unpersuasive
because, as noted above, the rejection relies on Claude as evidencing that
designing steering system to have Ackermann geometry was known and
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

20
practiced in the art, and thus, to any extent Irikura’s gear pairs do not
provide a substantially Ackermann steering system as disclosed, it would
have been obvious to further modify Irikura to provide such a steering
system.
In addition, although Claude does use the term “cam” to refer to
structural components, it also appears to use the term to more broadly refer
to non-circular rotation about offset centers of rotation along the interface of
the components, and discloses use of gears in attaining such movement.
Claude, pg. 1, ll. 23–32 (“the path to the solution is by . . . the determination
of the method of calculating the steering cams, their development and
optimum form and, connected therewith, the form of the gearing which as
the support or the generator of the steering cams transmits the movement to
the steering wheels of the vehicle in suitable manner” (emphasis added)); pg.
1, ll. 49–54 (“Fig. 1 shows the wheels with the new cam mechanism and a
cam bar drive. Fig. 2 discloses the theoretical construction of the cams. Fig.
3 is a view showing a development of the cams.”). In that regard, Figure 2
of Claude clearly shows the interface of its components as having a curved,
non-circular shape, which would suggest similar shape in a gear interface to
the extent mating gears are not shown.
Regardless, Claude further discloses an alternative having a gear
implementation/embodiment, thereby establishing that it was known to have
implemented cam-based suspension geometries and systems using gears
instead of cams. Claude, pg. 1, ll. 51–55 (“Fig. 4 illustrates an embodiment
of the gearing illustrated diagrammatically in Fig. 3.”); pg. 2, ll. 113–128
(“The steering gear shown in Fig. 4 does not differ in principle from the
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

21
steering gear shown in Figs. 1 and 2. The bevel pinion K2 is the support of
the circular steering cam corresponding to the cam disc E. The bevel pinion
K' with its driving parts is a generator of the steering cam calculated from
the relations . . . corresponding to the cam disc A. The bevel pinion K is the
intermediate member controlling the two bevel pinions K' and K2 in
dependence on one another corresponding to the cam disc J in Fig. 2 or the
cam bar replacing it in Fig. l.”).
Therefore, even if Irikura’s gear pairs with non-uniform gear ratio
needed to be redesigned to provide substantially Ackermann steering, Irikura
and Claude provide sufficient evidence that such redesign would have been
within the skill and creativity of a person of ordinary skill in the art. In that
regard, we further find the declarant’s treatment of a person of ordinary skill
in the art to be problematic. On the one hand, the declarant asserts that a
person of ordinary skill in the art as having the skills and knowledge to
review both Irikura and Claude, and despite their explicit disclosures
regarding minimizing transverse slip, would have deduced using
trigonometry and calculus in the specific manner set forth in the declarations
to attain the derivative Ackermann equation, and determine that these
references do not disclose Ackermann steering systems. Reinholtz Decl. 1
¶¶ 13–15, 56–61; Reinholtz Decl. 2 ¶¶ 5–18, 21–23, 27–32. On the other
hand, the declarant states that this same person of ordinary skill, upon
concluding that these references do not disclose Ackermann steering
systems, would have abandoned using either Irikura or Claude, discard their
teachings, and would have been incapable of applying the same skill and
knowledge to remedy any purported deficiencies of the disclosed steering
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

22
systems. Reinholtz Decl. 1 ¶¶ 29, 62–66; Reinholtz Decl. 2 ¶ 32. In
particular, the declarant states that modifications would have to replace gears
and linkages, as well as steering gear box and pivotal joints with new
components so as to result in Ackermann steering, and that the specific
needs of a zero-turn radius Ackermann steering system are more
complicated and beyond the skill of those of ordinary skill in the art.
Reinholtz Decl. 1 ¶ 64.
However, we do not agree with the Patent Owner that a person of
ordinary skill and creativity would have simply abandoned the teachings of
Irikura and Claude considering their explicit teachings and lack of any
steering system in Hauser. Indeed, in view of the evidently high skill of
those of ordinary skill in the art attested to by the declarant, it is not apparent
why such a person would not have the skills to apply the same skills and
knowledge, as well as creativity to modify the variable gears of Irikura to
any extent necessary, with or without Claude teachings, or why such
modifications would have been beyond their skill and creativity.
Accordingly, we find this testimony of the declarant to be not credible, and
agree with the Examiner that “[t]he teachings of Claude and Irikura ’725
provide POSITA with an adequate understanding of the use a variable gear
pitch line providing a non-uniform gear ratio in order to achieve a ZTR
steering system that satisfies (or at least substantially satisfies) the
Ackermann equation and provides for the pure rolling movement that is
desired for eliminating wheel skid.” Ans. 22.

Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

23
Teaching Away
The Patent Owner further argues that “when properly considered in its
entirety, Irikura ’725 would have led a POSITA away from the proposed
combination” because Irikura “teaches abandonment of a configuration in
which each of two hydrostatic transmissions . . . controls a respective one of
two driving wheels” as disclosed in Hauser. App. Br. 18; see also App. Br.
91–92. Thus, the Patent Owner argues that:
To use Hauser’s hydrostatic drive units 16, 18––the alleged left
and right hydrostatic drive units of the claims––a POSITA
would have had to ignore the primary purpose of Irikura [], i.e.,
to avoid the “labor [required] for precise coincidence between
the capacities of” the pumps and motors of the hydrostatic drive
units.
App. Br. 95–96, quoting Irikura ¶ 8; see also Rebuttal Br. 5–6.
The Examiner finds that the prior art teaches well-known alternative
transmissions, and concludes that a person of ordinary skill in the art would
have found it obvious to utilize such known transmissions based on “the
known advantages/disadvantages thereof as well as the particular design
criteria involved.” Ans. 18; see also Ans. 23.
We generally agree with the Examiner. Although the Patent Owner is
correct that Irikura discloses the disadvantage of using hydrostatic drive
units for separately driving left and right wheels, and further discloses its
solution therefor, as discussed above, Irikura also clearly teaches a steering
system for the steerable front wheels for use in a zero radius turn vehicle.
There may be many reasons that a person of ordinary skill in the art may
have implemented only Irikura’s teachings with respect to the steering
system, but not its teachings regarding hydrostatic drive units. For example,
Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

24
engineering considerations such the specific application, manufacturability,
durability, serviceability, and other considerations such as costs and market
familiarity. Although the Patent Owner argues that “the Office fails to
enumerate any advantages of Hauser’s drive units 16, 18 and/or
disadvantages of Irikura ’725’s driving/steering unit 10 that would have led
a POSITA to choose Hauser’s drive units over Irikura ’725’s” (App. Br. 96),
we find sufficient, the Examiner’s general reasoning in view of the art that a
person of ordinary skill in that art would have considered numerous factors,
and that it would have been obvious to such a person to have applied the
multiple independently teachings of Irikura selectively. Further, the
Examiner’s rejection begins with Houser, which already has a hydrostatic
drive system specified, and directs one of skill in the art to find a suitable
manner of steering it. Thus, we see no reason the Examiner would have had
to address keeping Houser’s existing drive system. We think it is
unreasonable, and do not expect, the Examiner to articulate the rejection in
such level of detail asked for by the Patent Owner, who essentially relegates
a person of ordinary skill to an automaton that would have bodily
incorporate all the teachings of Irikura into the mower of Hauser.
Therefore, in view of the above, we affirm Rejection 1. The
remaining dispute between the Examiner and the Patent Owner regarding the
broader scope of the claims on appeal is moot. Ans. 17; App. Br. 86; see
also Final Act. 18, 20, 22.

Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

25
Rejection 2: Hauser, Irikura, Claude, Barnes and LaserZ
The Examiner rejects claims 11–20 as unpatentable over Hauser in
view of Irikura, Claude, Barnes, and LaserZ. Final Act. 12. The Patent
Owner relies on arguments submitted with respect to Rejection 1 for
patentability of these claims. App. Br. 97. However, as discussed above,
these arguments are unpersuasive.
The Patent Owner also points out that independent claim 11 recites
that the left and right front steerable, non-driving wheels are “rotatable to a
zero radius turn.” Appeal Br. 98. The Patent Owner then argues that “[a]s
shown above, a POSITA would have understood that neither Irikura ’725’s
steering system nor Claude’s steering system provides this functionality”
(Appeal Br. 98), and that “[t]he Examiner’s Answer fails to respond to this
independent basis for reversing its rejection.” Rebuttal Br. 7.
This argument is unpersuasive. Although the Patent Owner has
argued that the steering systems of Irikura and Claude do not provide fully
Ackermann steering as discussed above, Irikura clearly discloses a zero
radius turn capable steering system. Irikura, Fig. 44; ¶ 194 (“left wheel 43L
serving as inside wheel 43 rotates backward while right wheel 43R serving
as outside wheel 43 rotates forward, so that the turning center of the vehicle .
. . is placed on the lateral middle point between wheels 43L and 43R. . . .
Since point 196 coincides with the lateral middle point of the vehicle, the
vehicle turns centering on its own lateral middle point. In other words, the
vehicle spins.”).
Therefore, Rejection 2 is affirmed.

Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

26
Rejection 3: Hauser, Irikura, Claude, Barnes, LaserZ and Paramythioti
The Examiner rejects claims 16–20 as unpatentable over Hauser in
view of Irikura, Claude, Barnes, LaserZ, and Paramythioti. Final Act. 13.
The Patent Owner relies on arguments submitted with respect to Rejection 1
for patentability, noting that deficiencies of the proposed combination of
Hauser, Irikura, and Claude is not remedied by the remaining references
relied upon by the Examiner. App. Br. 99. Thus, being unpersuaded of
deficiencies in the combination of Hauser, Irikura, and Claude, we affirm
Rejection 3.
CONCLUSION
The Examiner’s Rejections 1–3 are AFFIRMED.
DECISION SUMMARY
In summary:
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1–10 103(a) Hauser, Irikura,
Claude, Barnes
1–10
11–20 103(a) Hauser, Irikura,
Claude, Barnes,
LaserZ
11–20
16–20 103(a) Hauser, Irikura,
Claude, Barnes,
LaserZ,
Paramythioti
16–20
Overall
Outcome
1–20

Appeal 2019-001226
Reexamination Control 90/013,980
Patent US 9,254,865 B2

27
REQUESTS FOR EXTENSIONS OF TIME
Requests for extensions of time in this ex parte reexamination
proceeding are governed by 37 C.F.R. § 1.550(c). See 37 C.F.R. § 41.50(f).
AFFIRMED

SDC

For Appellant:

NORTON ROSE FULBRIGHT US LLP
98 San Jacinto Boulevard, Suite 1100
Austin, TX 78701-4255

For Third Party Requester:

James W. Miller, (General)
527 Marquette Avenue, Suite 1960, Rand Tower
Minneapolis, MN 55402