Ex Parte Borgen

Patent Trial and Appeal Board

Jun 25, 2014

10599109 (P.T.A.B. Jun. 25, 2014)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE PATENT TRIAL AND APPEAL BOARD
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Ex parte EYSTEIN BORGEN
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Appeal 2012-001387
Application 10/599,109
Technology Center 3700
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Before: EDWARD A. BROWN, CHARLES N. GREENHUT, and
PATRICK R. SCANLON, Administrative Patent Judges.

GREENHUT, Administrative Patent Judge.

DECISION ON APPEAL

STATEMENT OF CASE
Appellant appeals under 35 U.S.C. § 134 from a rejection of claims 1–
12. App. Br. 1. We have jurisdiction under 35 U.S.C. § 6(b).
We reverse.
The claims are directed to a method for reduction of axial power
variations of a wind power plant. Claim 1, the sole independent claim,
reproduced below, is illustrative of the claimed subject matter:
Appeal 2012-001387
Application 10/599,109

2
1. A method for controlling the output of a wind power
plant comprising a converter unit, the method comprising
establishing an output power range for the converter unit,
measuring the output power of the converter unit, and if the
output power of the converter unit is within said range,
changing the pitch angle of the rotor blades in order to
minimise variations in the thrust of the rotor blades in the wind
direction individually or collectively, and if the output power of
the converter is outside this range, changing the pitch angle of
the rotor blade in order to bring the power output within the
range.

REFERENCES
The prior art relied upon by the Examiner in rejecting the claims on
appeal is:
Kojima
Rebsdorf
US 4,653,982
US 6,619,918 B1
Mar. 31, 1987
Sep. 16, 2003

REJECTIONS
Claims 1, 6–8 and 10–12 are rejected under 35 U.S.C. § 102(b) as
being anticipated by Rebsdorf. Ans. 4.
Claims 2–4 and 9 are rejected under 35 U.S.C. § 103(a) as being
unpatentable over Rebsdorf. Ans. 6.
Claim 5 is rejected under 35 U.S.C. § 103(a) as being unpatentable
over Rebsdorf and Kojima. Ans. 7.

OPINION
The Examiner found that “[s]ince Rebsdorf makes pitch adjustments
relative to wind speed which is directly correlated to power output as shown
in Fig. 2, a person having ordinary skill in the art at the time of the invention
Appeal 2012-001387
Application 10/599,109

3
that [sic] Rebsdorf makes pitch adjustments relative to power output.” Ans.
8. While graphed against wind velocity, Rebsdorf expressly states that, “the
pitch of the blades is controlled to keep a constant power output.” Col. 3, ll.
25–26; Fig.2 (illustrating a “typical power curve”). This control, in turn,
appears to correlate to reduced or stabilized mechanical loads Lm on the
blades of the rotor. Col. 3, ll. 32–36; Fig. 3. These mechanical loads on the
blades may be related to “thrust,” which is used in Appellant’s Specification
to refer to an axial force exerted on the rotor. Spec. 3:4–6, 13–14.
However, there does not appear to be any disclosure in Rebsdorf of
“changing the pitch angle of the rotor blades in order to minimise variations
in the thrust of the rotor blades” as required by claim 1. (Emphasis added);
App. Br. 8 (paraphrasing this limitation as “stress-reducing” type pitch
adjustments). The phrase “in order to” implies that the control of the pitch
angle is a function of thrust changes. The Examiner has not apprised us of
how this limitation is met by Rebsdorf. Since all of the rejections before us
are based on Rebsdorf allegedly disclosing such a feature, the Examiner’s
rejections cannot be sustained.
DECISION
The Examiner’s rejections are reversed.

REVERSED

Klh