New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1894-10-01

he claims is much more efficient besides possessing
numerous other eXcelences.
Mr. Sperry's idea is to energze his brake not
with current derived from the trolley wire. but with
electricity manufactured on the spot at the moment
OF application Thus he avoids drawing on the
resources Of the power house. and utilities energy
that costs nothing: and what Is Of much more con-
sequence. his mechanism is not rendered he pless by
an interruption Of the regular trolley current When
the latter is shut off entirely in the usual manner
BY the mOtornan. 1t is provided that the motor
shall be changed into generator. Then. instead OF
electricity being converted into power the stored
power Of the moving car is converted into cleo
tricity This operation alone puts a drag upon the
car-axles But there is further check imposed
The current developed under these circumstances
is led off into coils, which Embedded in iron
plates as TO magnetic them. These plates are the
brakes They are not applied to the tire of the
wheels like the ordinary brake. but 10 the nat
inner surface. Magnetic attraction compels them
10 press firmly against the wheel. and thus bring a
second factor friction. into play Finally the excl
taton in the two masses of iron steel, of what
are called "Foucault currents" usually a bother
some phenomenon, in this performs an ac-
ceptabIe service by still further clogging the rota-
ton.
Instead Of having these brakes on all four wheels
of each truck. Mr.. Sperry has but to each axle
The inner face of the wheel is moulded and ground
fat TO afford a good contact; and the brake plate
Is circular. Owing to the method Of its generation
the brakng current dimnshes with the speed OF the
car although some sight residual effects per-
cep,ble after stoppage Hence II is strongest when
most needed and its intensity is automatically regu
lated. This Is Improvement upon hand brakes
and air brakes. II is impossible TO stop wheel
with Mr. Sperrys brake so that the former will slide
on the rail and itself fat: yet in emergency II
can be made TO stop within its own length
II Is said that at such times inmates of the car
feel IL II had struck feather bed or air cushion
and not a solid obstacle. The brake always has
clean surface, too. The ordinary brake-shoe often
has sand and mud thrown upon Its face and this
grit not only prevents good braking contact. but
also acts destructvely the wheel Hence there
is a distinct reduction Of the and tear OF
rolling stock incident to the of such brake.
This device too is said TO be entirely noseess In its
operation. The ordinary hand brake has. in
Instances where this electric brake Is in service
been retained: but ordinarily 1t may be dispensed
with. and the motorman may thus be relieved OF
what is the hardest part OF his work.
The application OF the brake is not entirely auto
matte however. The current which actuates II Is
led through the controller" This Is the mechan-
ism seen the front platform of every trolley car
surmounted with a lever crank by OF
which the motorman regulates the speed OF the
car. Just as ne may gradually increase and de-
crease the amount of propeing current by moving
the handle and fro. just he controls the brak-
ing current when the latter is IL o1eration. The