Improvements in and connected with Brake Shoes for Electric Braking Apparatus.
Year: 1897

page_text: Date of Application, 25th Jan., 1897-Accepted, 13th Mar., 1897
COME DUID SI DUITATION.
Improvements in and connected with Brake Shoes for Electric
Braking Apparatus.
We, THE BRITISH THOMSON-HOUSTON COMPANY, LIMITED, of 83, Cannon
Street, in the City of London, Electrical Engineers, do hereby declare the nature
of this invention (which has been communicated to us from abroad by Frank
E. Case, of Schenectady, County of Schenectady, State of New York, United
States of America,) and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :--
Our invention relates to brake shoes for electric braking apparatus, and their
mounting; and has for its object to provide a form of shoe and a mounting therefor,
which may be adapted not only to original installations, but also to old cars of any
type. It consists briefly of a special form of shoe which is best adapted to our
invention, although the invention is not confined entirely to its use, and a means of
preventing the rotation of this shoe which shall be in a measure independent of
the truck and capable of application to all existing apparatus with which we are
familiar.
Our invention is best understood by reference to the drawings, in which
Fig. 1 is a side elevation of the two shoes applied to the axles of a trailer car
without motors;
Fig. 2 is a modified form to be applied to a motor car;
Fig. 3 is an enlarged detail view of the shoe in side elevation ;
Fig. 4 is a plan of the parts shown in Fig. 3;
Fig. is a section upon the line 5-5 of Fig. 3;
Fig. 6 is a sectional detail upon the line 6-6 of Fig. 3.
In Fig. 1, A, A are the car wheels, B, B the shoes, which are duplicates ; C is a
connecting bar independent of the truck frame, having lugs c, c upon its ends to
prevent its displacement; D, D are retaining plates secured by bolts to the brake
shoe.
The special construction of the shoe and bar is best shown in Fig. 3. In that
figure b, b1 are lugs which are formed upon the shoes, as shown particularly in
Fig. 6.
Between the lugs the bar C is placed, its action being to prevent the
rotation of the brake shoe. It makes with the lugs a slightly loose fit so as not to
cramp in turning corners or in minor motions of the axle. The same parts are
shown in Fig. 4; E being the car axle, and K being the collar keeping the shoe in
proper place on the axle E. The lug is threaded into the axle, and the set-
screw L engages with the collar to take up any play that may arise from wear of
the parts. This is best shown in Fig. 5, which also best illustrates the retaining
plate D. As will be seen from comparison of Figs. 3 and 5, this plate is inter-
mediate between the sets of lugs b, b¹ on each side of the center, and it is secured by
bolts to the body of the brake shoe. Opposite the plate is a coil spring bearing
against the bar C and preventing any rattling of the bar C and shoe. The
spring should be just sufficiently stiff for this. The bar C is made a slightly
loose fit in the recess formed by the plate D and the shoe, so that the bar will not
cramp in vibrations of the axle. Each of the brake shoes B is provided at its
upper portion with an oil cup B' having a hinged cover B2 held in close position by
means of a spring hinge B³, all as clearly shown in Fig. 5 of the drawing. N, Nare

page_text: the coils embedded in the brake shoe, their use being well understood. I is the
co-operating disc secured to the axle and forming a friction surface for the shoe.
Referring now to Fig. 2, we show how a single shoe may be mounted upon an
idle axle of the truck and embody. our invention. In this case G is a cross bar or
other convenient portion of the truck, which is not illustrated as a whole, and H is a
pin. The bar C is in this figure shown as bent so as to engage with the cross
bar G and is held in place by the pin H.
In Fig. 3 the electric connections are indicated at x, y, but these form no special
part of the present invention, being well known in the art.
The construction described is one well adapted to the idle axles of electric cars
or other vehicles, the ordinary forms of brake shoe being intended only for
application to motor-driven axles, and being therefore arranged to be supported
upon a part of the motor. As ordinarily arranged, these shoes are inconvenient of
application to idle axles, and require, when so adapted, to be secured at some point
to the truck frame, so that their rotation may be prevented. In many forms of
equipment the truck frame is not sufficiently strong to provide for this, and to such
apparatus the form of our invention shown in Fig. 1 is well adapted, as it brings
no additional strain upon the truck; but in motor-driven cars the trucks are
ordinarily amply strong so that the brake shoes may be used as shown in Fig. 2.
Having now particularly described and ascertained the nature of this invention
(as communicated to us from abroad) and in what manner the same is to be
performed, we declare that what we claim is :-
1. A disc electro magnet brake shoe, having a disc mounted on a car axle, and
provided on its face with sets of lugs and a retaining plate intermediate of said
lugs in combination with a locking bar located in said lugs and held in position
by said plate, the bar being secured to prevent rotation of the shoe, as herein set
forth.
2. A pair of disc electro magnetic brake shoes, each mounted on a separate car
axle and each having lugs and a retaining plate, in combination with a locking bar
engaging said lugs on both shoes.
3. In combination, a brake-shoe provided with lugs having a recess between
them, a bar in the recess, a plate for retaining the bar in position, and a spring for
taking up the play of the
the parts
Dated this 20th day of January 1897.
For the Applicants,
J. C. CHAPMAN,
70, Chancery Lane, London, W.C., Chartered Patent Agent.