Appeal No. 97-0210
Application No. 08/157,050
The method may additionally comprise the step of
maintaining the voltages of the currents
proportional to the rotational speed of the rotor.
This enables the motor to more readily develop and
maintain torque.
By short-circuiting the windings, the motor becomes
asynchronous. Further, decreasing the voltages decreases the
rotational speed of the rotor, as the speed of the rotor is
proportional to the voltages of the currents. As claim 11
does not preclude additional factors for adjusting the speed
of the motor, and Demeter teaches a step of maintaining
voltages proportional to the rotor speed, Demeter meets the
limitation of adjusting the speed of rotation of a pole-
changing asynchronous motor by decreasing the voltage
supplied. Accordingly, we find that Demeter does anticipate
claim 11. In addition, since claims 23 and 24 stand or fall
with claim 11, we also affirm the obviousness rejection of
claims 23 and 24.
Claims 2 through 21 each require two speed ranges, one in
which the speed is adjusted stepwise, and the other in which
the speed is adjusted continuously. Demeter discloses a
stepwise increase in speed when the motor is synchronous, and
a continuous adjustment in the speed when the motor is
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