Improvements in Street Car Brakes.
Year: 1896

page_text: Date of Application (in United Kingdom), 8th Dec., 1896
Improvements in Street Car Brakes.
I, WILLIAM GUNN PRICE, of Number 2020 State Street, in the City of Chicago,
County of Cook, State of Illinois, United States of America, Mechanical Engineer,
do hereby declare the nature of this invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement:-
My invention relates to that class of brakes for vehicles operated by means of
a moving part on the vehicle, and is illustrated in the accompanying drawings,
wherein Figure 1 shows a plan view of a street car truck provided with one form
of my brake mechanism; Figure 2 is a section on line 2-2 of Figure 1, with
parts omitted; Figure 3 is a section through the street car wheel and the friction
disk associated therewith, said disk being connected with the brake shoes;
Figure 4 is a side view of the controlling levers by which the position of the
friction disk is varied; Figure 5 is a plan view of the same with the actuating
screw in position; Figure 6 is a section through the car wheel and friction disk
in which the friction disk is mounted direct upon the axle; Figure 7 is a face
view of the oil box associated with the levers shown in Figure 4; Figure 8 is
a view in part section of a portion of a car truck showing a modified form of
actuating mechanism for the friction disk; Figure 9 is a section on line 9-9
of Figure 8; Figures 10 and 11 are enlarged views of the parts of the friction
disk controlling mechanism which surround the car axle and which are shown
in Figure 9.
Like parts are indicated by like letters throughout the several figures.
I have illustrated in the drawings two forms of my device in order to show
different applications of the same. But it is, of course, evident that I have
not endeavored to show all the different forms which my device may take.
As shown in Figures 1 to 7 inclusive, a friction disk A is associated with one
of the car wheels and is provided with a mechanism by which it may be brought
into contact with such car wheel so as to move therewith. This friction disk
is normally stationary, the axle rotating within the disk, and the disk is con-
nected by intermediate mechanism with the brake shoes associated with the
wheels of the car. The chain or power transmitting device A' is connected at
one end with the disk A, the other end being connected with the equalizer A³,
гр. 022

page_text: This equalizer is connected by the rod A³ with the arm A, which is connected
with the brake beam A. The other end of the equalizer is connected by a
rod A with the lever A', said lever being connected by rods As to the brakes of
the adjacent car or trailer which may be placed at either end of the car carrying
the brake mechanism. The disk A is provided with a hub B, a portion of said
hub being reduced in size, as at B, to carry the actuating mechanism for the
disk (see Figures 3 and 6). As shown in Figure 3, a sleeve B2 provided with
the collar 13 is slipped upon the axle B before the wheel is placed in position
and is held in place by the key B. As shown in Figure 6 this sleeve is omitted,
the collar B being attached diectly to the axle. Two levers C C¹ are provided
with bifurcated ends which engage the reduced portion of the hub B so as to
be interposed between the enlarged part of the hub and the collar B. These
levers are shown in Figures 4 and 5. A screw C2 works in a threaded hole in
the lever C and bears against the lever C, so that when rotated in one direction
the bifurcated ends of the levers are separated so as to force the friction disk
against the wheel. This screw is provided with the toothed head C, said head
being engaged by a toothed lever C which is held in place by means of a nut.
This construction allows the lever to be adjusted to take up the wear of the parts.
This lever is connected by means of the rods C to the pivoted pieces or sockets C
at each end of the car. Said pivoted pieces are constructed so that the handle C
can be inserted therein in order to move them and thus move the screw C². The
levers C and C are pivoted together at and rest upon the cross piece C. The
outer ends of these levers are free to move laterally, but are prevented from moving
away from the brace by means of the guide Co. A lug C on the lever C₁
prevents said levers from moving away from the car axle. It will be seen that
when the parts are in position and the handle C7 is moved, the screw C2 will
be turned so as to separate the bifurcated ends of the collars C C, and since one
of the levers engages the collar 13 and the other engages the hub of the friction
disk A, this movement of the levers will force the disk against the wheel. The
frictional contact between the wheel and the disk causes said disk to rotate,
thereby forcing the brake shoes, by means of the intermediate mechanism,
against the wheels of the car. If the outer ends of the levers C and C¹ are not
free to move laterally, the disk A will be forced with too great a pressure against
its opposed surface when the car is not on a perfectly level track, thereby destroy-
ing the leather disk or washer D which is interposed between the car wheel and
the friction disk. This destroying of the leather disk when the ends of the
levers are rigidly connected with the car frame or truck is due to the slipping
of the car body with relation to the wheels as the level of the two rails upon
which the car runs varies, the car body being thrown to the side which is lowest.
In order to oil the engaging parts of the mechanism for operating the disk, I
may provide an oil cup D which is placed between the bifurcated ends of the
levers and which is held in place by means of the strap D2 preferably of leather.
This oil cup is provided with an oil absorbing material, as for example waste,
and is provided with the openings D3 and the partition D. The brake beam As
is connected with the brake beam E by means of the rods EE (see Figures 1
and 2). When the friction disk 'A is associated with the car wheel, it acts when
in engagement with said wheel, to retard the motion of the wheel. It will
therefore be seen that if the brake shoe opposed to this wheel acts with the same
force as the other brake shoes, this wheel will cease to rotate before the brake
has become fully applied to the other wheels, and a "flat" wheel will result.
In order to avoid this I connect the rods E, and E2 when two such rods are used,
to the brake beam or brake shoe or shoes associated with this wheel so as to
reduce the pressure of the brake shoes. The connection of these rods will be
such that the pressure on the brake shoes opposed to the wheels with which the
friction disk is associated will be less by an amount equal to the retarding effect
of the friction disk than will be the pressure of the brake shoes associated with
the other wheels of the car. In the drawing I have accomplished this result

page_text: by using a different lever arm to connect the rods E and Ea with the brake
beam E than is used to connect them with the brake beam A5.
The hub of the friction disk A is provided with the annular receptacle F for
oil. A wick F is placed within said receptacle, there being an opening through
the hub so that the wick comes in contact with the surface beneath.
hollow receptacle is provided with an oil hole.
This
In Figures 8 to 11 inclusive, I have shown a modification of the actuating
mechanism for the friction disk. In this form of my device. the two.levers H H¹
are loosely connected together by means of the bolt H, the end of the lever H
being loosely held in position by means of the loop H³ on the cross piece Co.
Each of the levers H and H is provided with the enlarged end H which surrounds
the axle, these enlarged ends being located on the reduced portion of the hub
of the friction disk. An intermediate arm H is located between the two levers
and is connected with the arm H so as to be moved thereby, said latter arm
being pivotally connected to the projecting lugs H7 on the levers H and H¹.
This arm He is connected by means of rods with the operating handles on the
car. The arm H5 is bifurcated at one end, the branches H8 of the bifurcated
portion being wedge shaped and being interposed between the ends H* of the
levers H and H. "Either or both of these end pieces H may be wedge shaped
if desired. It will be seen that the ends of the levers H and H' may be separated
by forcing this wedge shaped piece between them, thereby pressing the friction
disk against the wheel. The arm H5 is provided with an adjusting device H
which allows it to be adjusted to take up the wear of the parts. It will be seen
that by this construction the position of the wedge shaped ends H may be con-
trolled by the operating handle on the car. This operating handle is removably
connected with the piece C, said piece being provided with a socket to receive
the handle.
I have shown the above described forms of my device in order to clearly
illustrate its use; but it is of course evident that I have not endeavoured to illus-
trate all the various forms which would embody my invention. This invention
may be used upon vehicles of all kinds, but it is particularly adapted for use upon
street cars operated by electric motors, for when such electric motors are used
the space left on the axles for brake mechanism is very small, and such mechanism
must be of a peculiar construction in order to be used in such connection.
Having now particularly described and ascertained the nature of my
invention and in what manner the same is to be performed I declare that what
I claim is:
1. The vehicle brake illustrated in Figures 1 and 2.
2. A vehicle brake consisting of a friction disk opposed to a moving part on
the car and provided with a hub as shown in Figures 3 and 6, said disk con-
nected by intermediate mechanism with the brake shoes and provided with the
actuating mechanism shown in Figures 4 and 5.1
3. The herein described vehicle brake illustrated in Figures 1 to 5 inclusive.
4. In a brake mechanism the combination of a car wheel with an opposed
movable friction disk, a fixed collar on the car axle, two associated relatively
movable parts interposed between the disk and the collar, and an actuating
mechanism for forcing them apart, as herein shown and described.
5. The herein described brake mechanism illustrated in Figures 8 to 11.
inclusive.
6. The herein described adjusting devices for vehicle brakes.
7. A brake device for street cars comprising a friction device on one axle
opposed to a wheel and which actuates the brake shoes so as to apply them to
the car wheels, means associated with the brake shoes for reducing the pressure
or braking power on one side of brake shoes to an amount approximately equal
to the friction or braking power exercised by the friction device, as herein shown
and described.

page_text: 8. A brake for vehicles consisting of a collar fixed to the axle, a movable disk
in proximity to a wheel and provided with a projecting hub which actuates a
chain or rope to apply the brakes, a portion of said hub being reduced in size
so as to support or carry a mechanism adapted to actuate the disk so as to force
it against the wheel, as herein shown and described.
9. The brake mechanism for vehicles herein described and illustrated in the
drawings.
Dated this 8th day of December 1896
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.