Ex Parte Watanabe et al

Patent Trial and Appeal Board

Jan 29, 2014

11730093 (P.T.A.B. Jan. 29, 2014)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________________

Ex parte KATSUJI WATANABE, YASUO SHIMIZU
and TAKAHIRO AOKI
____________

Appeal 2011-010386
Application 11/730,093
Technology Center 3600
____________

Before: JENNIFER D. BAHR, PATRICK R. SCANLON and
WILLIAM A. CAPP, Administrative Patent Judges.

CAPP, Administrative Patent Judge.

DECISION ON APPEAL

STATEMENT OF THE CASE
Appellants seek our review under 35 U.S.C. § 134 of the final
rejection of claims 1 and 3-5 under 35 USC § 103(a) as being unpatentable
over Cheng (US 6,155,376, iss. Dec. 5, 2000) and Appleyard (US 6,357,313
B1, iss. Mar. 19, 2002). We have jurisdiction under 35 U.S.C. § 6(b). An
oral hearing in accordance with 37 C.F.R. § 41.47 was held on January 23,
2014.
We AFFIRM.
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THE INVENTION

Appellants’ invention relates to power steering systems. Spec. 1.
Claim 1, reproduced below, is illustrative of the subject matter on appeal.
1. An electric power steering apparatus comprising:
a motor;
a worm gear provided on a rotational shaft of the motor
so as not to rotate with respect to the rotational shaft;
a worm wheel gear which meshes with the worm gear
and links to a steering system;
a gear housing to which a motor housing of the motor is
attached, and which accommodates the worm gear and the
worm wheel gear;
a decentering device which makes the rotational shaft
approach to or depart from a rotational axis of the worm wheel
gear in a parallel manner thereto, by rotating the motor housing
with respect to the gear housing;
a first bearing which is accommodated in the motor
housing and supports one end of the worm gear;
a second bearing which supports another end of the worm
gear; and
a bearing cap which accommodates the second bearing
therein and is attached to the gear housing, wherein:
a first decentering amount is provided between a center
of a first protruding coupling portion of the motor housing and
a center of the rotational shaft of the motor;
a second decentering amount is provided between a
center of a second protruding coupling portion of the bearing
cap and the center of the rotational shaft of the motor;
the first decentering amount is equivalent to the second
decentering amount, thereby enabling the bearing cap to be
attached to the gear housing after an adjustment of a backlash
between the worm gear and the worm wheel gear; and
the first protruding coupling portion of the motor housing
extends towards and opposes the second protruding coupling
portion of the bearing cap.
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OPINION
Appellants argue claims 1 and 3-5 as a group. App. Br. 8-15. We
select claim 1 as representative. See 37 C.F.R. § 41.37(c)(1)(vii) (2011).
The Examiner finds that Cheng discloses all of the elements of
claim 1 except for a bearing on the distal end of the worm gear shaft
characterized by a decentering amount and capped with a bearing cap
attached by bolts to the gear housing through arc shaped bolt holes. Ans. 4-
5. The Examiner relies on Appleyard as disclosing Cheng’s missing
elements. Ans. 5.
The Examiner finds that Cheng, upon modification by Appleyard,
would be capable of making the worm gear shaft approach or depart the
rotational axis of the worm wheel gear in a parallel manner. Ans. 6. The
Examiner further finds that Cheng, upon such modification, discloses a
protruding motor housing coupling that extends towards and opposes the
bearing cap coupling. The Examiner finds that the combination of Cheng
and Appleyard discloses the claimed invention except for an equivalent
decentering amount. Id.
The Examiner concludes that it would have been obvious to a person
of ordinary skill in the art at the time of the invention to provide for
equivalent decentering. Ans. 6-7. According to the Examiner, such amounts
to the mere optimization of a result effective variable which is within the
ambit of ordinary skill. Ans. 7.
Appellants traverse the Examiner’s rejection by first arguing that the
cited prior art fails to teach or suggest both a first decentering amount and a
second decentering amount on the respective proximal and distal ends of the
worm gear shaft. App. Br. 9. In response, the Examiner observes that
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Cheng discloses one decentering device and Appleyard discloses another
decentering device. Ans. 8, 11. According to the Examiner, therefore, the
proposed combination has first and second decentering devices. Id.
We agree with the Examiner that the proposed combination meets the
limitations directed to two decentering amounts. Taken in context, the two
respective decentering amounts in claim 1 relate to providing decentering
devices at two different locations along the shaft of the worm gear. As we
understand the Examiner’s proposed combination, an eccentric would be
provided at each of two different positions along the shaft of the worm gear.
This would result in decentering amounts being provided at each of the two
eccentric locations. See Cheng, Figs. 2-6, Appleyard, Figs. 1, 2. Adding a
second decentering device to an apparatus that already uses a first
decentering device to adjust backlash does not impart patentability to
Appellants’ invention. See In re Harza, 274 F.2d 669, 671 (CCPA 1960)
(“[i]t is well settled that the mere duplication of parts has no patentable
significance unless a new and unexpected result is produced”).
Next, Appellants argue that the proposed combination fails to disclose
that the two decentering amounts are equal. App. Br. 10-12. Appellants
contend that the structural arrangement of having two equal decentering
amounts provides a particular advantage over the prior art, namely, it
enables the bearing cap to be attached to the gear housing after adjustment of
a backlash between the worm gear and worm gear wheel. App. Br. 12;
Reply Br. 4.
In response, the Examiner states that providing equal decentering
amounts is a function of the intended use of the apparatus and, therefore, is
entitled to little patentable weight. Ans. 9. The Examiner also explains that
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an amount of decentering constitutes a value that falls within an adjustable
range. Ans. 14. According to the Examiner, a person of ordinary skill in the
art would recognize that an adjustable value could be optimized. Id. The
Examiner concludes that it would have been obvious at the time of the
invention to optimize a decentering amount to reduce backlash. Id.
Appellants reply that the decentering amount limitations are directed
to a structural arrangement of parts, not an intended use. Reply Br. 3.
Appellants further reply that the decentering amounts may be equal
independent of the amount of backlash adjustment. Reply Br. 4. Appellants
argue that Cheng and Appleyard both teach backlash adjustment without
equal decentering. Reply Br.5. Appellants conclude that the Examiner has
failed to demonstrate that the invention is obvious, because, according to
Appellants, the Examiner was required to find a single prior art reference
that teaches two decentering devices with equal decentering amounts. Id.
We do not find Appellants’ arguments to be persuasive. Appleyard
discloses that bearings can be situated on both the proximal and distal ends
of an electric motor worm gear shaft. Appleyard, fig. 1. Cheng provides a
decentering device on the proximal end of a worm gear shaft. Cheng, figs.
2, 7-9; col. 4, ll. 7-12.1 Appleyard provides a decentering device on the

1 Cheng discloses that the motor and motor shaft can be reoriented
positionally to accommodate a worm gear and worm gear shaft that extend
along a line that is essentially tangent to a worm gear wheel.
In accordance with a preferred embodiment of the
invention, the motor axis 120 extends transverse to the
steering member 32 at a right angle. It is contemplated,
however, that the motor axis 120 could lie parallel to the
steering member 32 or at a different angle, such as 45°,
relative to the steering member.
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distal end of a worm gear shaft. Appleyard, fig. 1, col. 4, l. 54 – col. 5, l. 27.
Combining Cheng with Appleyard results in a worm gear shaft with bearings
and decentering devices at each of the proximal and distal ends of the worm
gear shaft. With respect to decentering amounts, only three possibilities
exist. The decentering amount at the distal end can be less than, equal to, or
greater than the decentering amount at the proximal end. “When there is a
design need or market pressure to solve a problem and there are a finite
number of identified, predictable solutions, a person of ordinary skill has
good reason to pursue the known options within his or her technical grasp.
If this leads to the anticipated success, it is likely the product not of
innovation but of ordinary skill and common sense.” KSR Int’l Co. v.
Teleflex, Inc., 550 U.S. 398, 421 (2007). We agree with the Examiner that it
would have been obvious to one of ordinary skill in the art at the time of the
invention to optimize a decentering amount to reduce backlash. We think
this optimization process would include not only the absolute value of the
decentering amounts at the proximal and distal decentering device, but also
the relative amount of one vis-à-vis the other. 2

Cheng, col. 4, ll. 1-7.
2 Assuming Cheng’s gearbox mounting flange 130 is oriented
perpendicular to the axis of rotation of the electric motor output shaft 120,
which is a common sense, reasonable assumption in view of Figures 2-10, a
person of ordinary skill in the art would reasonably expect the distal, free
end of Cheng’s electric motor output shaft 120 to exhibit approximately the
same amount of decentering movement (B in fig 9, C in fig. 10) at both the
proximal and distal ends of the shaft. Thus, using equal decentering
amounts at both ends of the shaft would be the single, most obvious
alternative to pursue out of the finite number of predictable solutions.
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We are not convinced by Appellants’ argument that the Examiner was
required to find a single reference that disclosed both proximal and distal
decentering devices. See KSR 550 US at 419 (“The obviousness analysis
cannot be confined by a formalistic conception of the words teaching,
suggestion, and motivation, or by overemphasis on the importance of
published articles and the explicit content of issued patents.”). Contrary to
Appellants’ argument, a determination of obviousness does not require the
claimed invention to be expressly suggested by any one or all of the
references. See In re Keller, 642 F.2d 413, 425 (CCPA 1981).
Next, Appellants argue that the equal decentering amount enables the
bearing cap to be attached to the gear housing after adjustment of the
backlash and this structural relationship provides a particular advantage over
the prior art. App. Br. 12. This argument is unpersuasive as Appleyard
allows a bearing cap (flange 102) to be attached to the gear housing after
adjusting the backlash. Appleyard, col. 4, ll. 13-35; fig. 1. Thus,
Appellants’ alleged improvement affords no particular advantage over the
prior art in this respect.
Finally, Appellants offer four additional arguments for patentability.
App. Br. 12-15, Reply Br. 7-9. Appellants argue that: (1) there is no reason
for a person of ordinary skill in the art to modify Cheng as proposed; (2) the
proposed combination would change the principle of operation of Cheng; (3)
the proposed combination would render Cheng unsatisfactory for its
intended purpose; and (4) the proposed combination would not have been
undertaken with a reasonable expectation of success. Id. None of these four
arguments has any substantive merit. The Examiner adequately responded
to these four arguments in the Answer. Ans. 15-20. We adopt the
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Examiner’s findings and well-reasoned analysis and discussion on these
issues as our own.
In view of the foregoing discussion, we believe the Examiner's
findings of fact are supported by a preponderance of the evidence and that
the Examiner's legal conclusion of unpatentability is well-founded.
Accordingly, we sustain the Examiner's unpatentability rejection of claims 1
and 3-5.
DECISION
The decision of the Examiner to reject claims 1 and 3-5 is
AFFIRMED.
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).

AFFIRMED

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