The Indianapolis times. [volume] (Indianapolis [Ind.]) 1922-1965, 1933-09-07
DICkL UT OOfOIION
SL0WNESS AS
WELL AS SPEED,
SAVANTS' COAL
Motor Revolving Twice
Daily Is Constructed by
Westinghouse.
BY DAVID DIETZ
Seripps-HoWard Science Editor


Slowness as well as speed some
times is required even in the
modern high-speed machine age
While automobile and railroad
builders are thinking Of greater and
greater speeds, while engineers are
attempting continuously to speed up
machines. q group of scientists at
the Westinghouse laboratories have
been working to see how slowly they
could make an electric motor go.
They have perfected a timing
motor that will revolve only twice in
the course Of an entire day.
But, according to L. w. Chubb,
director of research of the WeSting-
nous Electric and Manufacturing Co..
and T r. Watts. research engineer
who has co-Operated in the develop
ment. that is only the beginning.
They say that they could slow down
the motor to the point where it
would only make one revolution in
the course of a year.
Used in Building Clock
theoretically. they say, there is
no limit to the slowness which the
new motor can be made to achieve.
To show the usefulness of such a
motor. Chubb and Watts have used
it in the construction of an electric
clock. So far, the clock is labora
tory experiment only and not avail
able commercially.
A feature of the new clock is that
It has only four moving parts, each
one of which is necessary to operate
one of the hands. The clock has
four hands--an hour hand, a minute
hand, a second hand and split
second hand.
The fastest moving part of the
clock operates the spllt-second hand
and makes sixty revolutions per
minute. In other words, one revOlu-
ton of this hand is a second and
its motion over the dial designates
fractions of a second.
All Mechanism Visible
Ordinary clocks use gears to OBJ
tain the slow speeds needed for the
various hands. Even some of the
electric clocks now on the market
have motors which revolve sixty
times a second. Trains of gears or
cogwheels are required to reduce
this speed to that of the hands.
All the mechanism of the clock is
visible through a celluloid face
about 10 inches in diameter,
mounted in a horizontal position.
Just below the outer rim of the
clock face is the stationary portion
of the mechanism. 1t is a wire
wound iron circle known as a stator.
This stator is so wound as to pro-
duce a magnetic field around which
magnetism revolves 5000 times per
minute 1t has lib iron teeth
around its inside edge.
Inside this ring, but not touching
it. is the rotor or rotating portion
of the motor. Its outer edge has
40 iron teeth, two more than the
stator has.
There is a tendency for the mag
netiSm to jump from stator to rotor
when teeth are exactly opposite
each other. But owing to the diff
ferent number of teeth on Stator
and rotor only two teeth are oppo-
site each other at one time.
This gives a vernier effect around
the rest of the circle and the result
is that the rotor moves the distance
of two teeth for each revolution of
magnetism in the stator.
In other words, while the mag
netism is going $500 times a min
ute around the stator. the rotor is
turning only sixty times minute.
This is exactly the speed required
for the split-Second hand.
Around the inner edge of the ro-
tor ring are 122 teeth pointing to-
ward a second rotor ring with 100
teeth around its outer edge. This
brings about a speed of the second
rotor of one revolution per minute.
This is the desired speed for oper-
ating the second hand.
A permanent horseshoe magnet
attached to the second hand rotor
creates a magnetic field which is
used to drive the rotor of the min
ute hand Another magnet attached
to this rotor drives the hour hand
rotor