Improvements in connection with Brake Mechanism of Railway Vehicles.
Year: 1892

page_text: Date of Application, 6th Oct., 1892-Accepted, 12th Nov., 1892
COMPLETE SPECIFICATION.
Improvements in connection with Brake Mechanism of Railway
Vehicles.
I JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of
Middlesex Gentleman do hereby declare the nature of this invention (which has
been communicated to me from abroad by The Loughridge Brake and Car
Company a Corporation organized under the Laws of the State of New Jersey
U.S.A. and having an office in the City of Camden in said State) and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
This invention consists mainly in so constructing what may be termed the
"compensating element of brake mechanism for railroad vehicles that the said
compensating element, while substantially retaining its various positions of
advancement, cannot by reason of any of its compensating or adjusting movements
lock the brake shoes in contact with the wheels. The invention also consists in a
special combination of parts in the brake gear whereby the compensation may be
effected either automatically or by hand without any material change in known
constructions of braking mechanism whether actuated by hand or by power, and
the invention also comprises means for facilitating hand adjustment and means for
aiding the movement in taking up slack and for preventing such sudden reversing
of the moving element of the take up device as would preclude the holding of the
additional advance movement.
"
In the accompanying drawing the improved compensating device is illustrated
in connection with an element of the brake gear which is known as the "dead
lever, although, as hereinafter specified, the essential features of the invention may
be adopted in connection with any class of compensating devices in which a rack
and pawl or interlocking racks are used as elements.
Fig. 1 is a view partly in section and partly in elevation illustrating the appli-
cation of the improved device for taking up slack as applied to a form of brake
gear commonly used in the United States of America ;
Figs. 2 and 3 are diagrams on a larger scale illustrating the operation of the
device;
Figs. 4 and 5. are detached views illustrating modifications of the same;
Fig. 6 is a view similar to Fig. 1, but illustrating the compensating device in
another form and applied to brake gear having the brake beams hung somewhat
differently from those shewn in Fig. 1;
Fig. 7, is a view illustrating the form of compensating device shewn in Fig. 6.
but as applied to another form of brake gear;
Fig. 8 is an enlarged view illustrating the action of the compensating device
shewn in Figs. 6 and 7; and,
Figs. 9, 10 and 11 are views illustrating modifications in the construction of
such forms of compensating device.
In Figs. 1, 6 and 7, A Å¹ represent the inner sides of the wheels at one side of
the truck and B B two brake beams suspended from the truck and carrying the
brake shoes a al respectively, the shoe a acting on the wheel A and the shoe a'
acting on the wheel A.'.
Hung to a bracket bon the brake beam B is what is known as the "live"
lever D of the brake gear, the long arm of this lever being connected by a rod d
to the brake operating device, either hand or power, the short arm of the lever
being connected by a rod f to the short arm of another lever D¹ known as the
"dead
lever and which is hung to a bracket on the brake beam B¹. The
upper end of this dead lever is guided in a slotted arm or bracket 9 which in

page_text: the case of the truck shewn in Fig. 1 is hung to a lug g' on the bolster F of the
truck and rests upon a pin i projecting from the dead lever as shewn, while in the
case of the truck shewn in Fig. 6 it is rigidly mounted upon the bolster F and in
the truck shewn in Fig. 7 is mounted upon and projects inwardly from one of the
sills of the truck.
The upper end of the dead lever is usually retained longitudinally in the guide g
by means of a pivot pin constituting the fulcrum of the lever and as the shoes or
other portions of the brake gear wear, or as the parts of the gear slacken by
reason of the strength or "spring" of any of the said parts the pin must be
shifted so as to advance the upper or fulcrum end of the lever in the guide in
order to compensate for such wear or slackening.
The object of this present invention is to dispense with this adjustable fulcrum
pin and to provide an automatic compensating fulcrum which will follow any
advance in the movement of the fulcrum end of the dead lever or equivalent part
of the braking mechanism and will hold so much of the said advance as is
necessary for taking up the slack but will permit a slight backward movement
after each advance so as to prevent the locking of the brake shoes in contact with
the wheels.
In the construction shewn in Figs. 1. 2 and 3 a rack m is hung to the upper
end of the dead lever, this rack having a longitudinal slot m' for the reception of
the pivot pin n on the lever the said rack being adapted to engage with a pawl
tooth at the end of the guide g.
When therefore, there is such slack in the braking mechanism that the upper
end of the dead lever owing to the shaking and jarring of the car moves forward
or in the direction of the arrow Fig. 1. there will also be a forward movement of
the rack m and if this movement is to the extent of a tooth of the rack the latter
will be caught by the pawl tooth p and prevented from returning, the slot m¹
however permitting such play of the upper or fulcrum end of the dead lever
independently of the rack as will insure the carrying of the brake shoes free from
contact with the wheels after each advance movement of the lever, as will be
understood on reference to the enlarged views Figures 2 and 3 of the drawing.
To provide for taking up slack by hand a rods is hung to the upper end of the
dead lever, this rod being supported upon a roller s¹ which is hung in a bracket
depending from the car sill or frame. The rod s terminates at a point convenient
to the end of the car so that it can be readily manipulated and will afford provision
for taking up the slack in the brake gear by an outward pull upon the rod when-
ever it is desired, as for instance when the brake hose is being coupled between
the cars, the brake shoes, owing to the slot m always falling clear of the wheels
when the rod is released after being pulled forward.
Mounted upon the rod s is a weight t and after each forward movement of the
dead lever the momentum of this weight must be overcome before there can be any
reverse movement of the lever, hence ample time is afforded for the rack m to
engage with the pawl tooth p after each successive forward movement of the said
rack. A spring w mounted upon a loop y at the end of the guide g serves to press
downward upon the outer portion of the rack m and thereby prevent it from
being jarred or shaken out of engagement with the pawl tooth although the
weight of the rack itself may in some cases be relied upon to keep it in engagement
with the pawl.
Besides performing the function above described the weighted rod serves to aid
in the movement of the dead lever to take up slack, for whenever there is any
bumping of the car or other arrest of its forward movement the weighted rod
tends to move forward along with the rest of the brake gear, it being understood
that the slack is generally taken up by that dead lever which is at the foremost
end of the car of the car because of the said tendency of the entire brake gear
to move forward when the movement of the car is arrested.
Palpable modifications of the construction shewn in Figures 1, 2 and 3 are the
reversal in the relation of the rack and pawl, such as shewn in Figure 4, the pawl

page_text: in that case being carried by the dead lever and the rack being formed on the
guide or the reversal in the relation of the slot m' and pin n shewn in Figure 5
where the slot is shewn as formed in the dead lever and the pin is carried by the
rack m a like arrangement of pin and slot being also permissible when the pawl p
is the element carried by the dead lever.
The weighted rod s may in some cases be combined with the dead lever, as shewn
by dotted lines in Figure 1 the rod in that case being supported so as to relieve the
lever of its weight and permit said lever to move more easily, a simple rod in this
case running from the lever to the end of the car to form the pulling rod, or the
weight may if desired be mounted directly on the lever as shewn by dotted lines in
Figure 2.
Another means of effecting a falling off or backward movement of the com-
pensating device after each advance or forward movement so as to permit the shoes
to fall clear of the wheels is that shewn in Figures 6 to 11 where instead of
providing a lost motion connection between the dead lever and the compensating
rack or pawl the said rack or pawl is hung to the dead lever by a close fitting pivot
but has its toothed portion undercut so that after the rack has advanced sufficiently
to permit one of its teeth to engage with the pawl or the pawl has advanced
sufficiently to engage with one of the teeth of the rack, such act of engagement will
permit a back movement of the rack or pawl and consequently of the end of the
dead lever carrying the same sufficient to cause the brake shoes to fall clear of the
wheels.
In the construction shewn in Figures 6, 7 and 8 the undercut rack m is adapted
to engage with the undercut tooth at the outer end of the guide g while in
Figure 9 an undercut tooth on a pawl p' carried by the dead lever is adapted to
engage with an undercut rack m on the guide g and in Figure 10 an undercut
tooth on a pawl hung to the dead lever engages with a ladder-like rack formed by
transverse bars or pins carried by the guide, and in Figure 11 an undercut rack
hung to the dead lever is supported vertically by a roller v on the guide and is
engaged by a pawl tooth p³ pivoted to a lug on said guide.
In applying the weighted rods to a compensating device having the undercut
rack or pawl the said rod is connected directly to or forms a continuation of the
said rack or pawl as shewn for instance in Figures 6 and 7.
The use of the weighted rod while preferred for the reasons before given, is not
absolutely essential in every case, as the shaking movements of the dead lever may
be wholly relied upon to effect the taking up of the slack in the brake gear if
desired, or the compensating rack or pawl may be provided with suitable hand
holds as shewn for instance by dotted lines in Figures 8 and 10 to facilitate the
movement of the said parts in taking up slack by hand.
Although the improved compensating device is illustrated in the drawing only as
applied to the dead lever of the braking mechanism, it should be understood that
the invention is not limited to the use of the said compensating device in this
connection.
As an instance of another use of the same may be cited its application to the
intermediate lever of a braking device, such for instance as shown at E in Figure 15
of the United States Patent Number 422,237, as a substitute for the filling
block J which is there shown as a means for holding the fulcrum of the lever in its
successive positions of advancement, and the feature of undercutting or the lost
motion connection may be applied with the advantages hereinbefore noted to all of
that, class of compensating devices which consist of a rack and pawl for interlocking
racks used in connection with various forms of car braking mechanism.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1st. The hereinbefore described device for compensating for wear or looseness of
parts of brake mechanism of railway vehicles the said compensating device comprising

page_text: elements with undercut engaging portions or lost motion connections whereby after
each successive advance or movement of compensation, there will be a slight
backing off to prevent the locking of the brake shoes against the wheels of the
vehicle substantially as hereinbefore described.
2nd. The combination of the dead lever of railway vehicle brake mechanism with
an engaging rack and pawl for retaining the fulcrum end of the said lever in its
successive positions of advancement, one or both of the said engaging portions
having undercut teeth, or the portion which is hung to the dead lever having a
slotted connection therewith substantially as hereinbefore described.
Third. The combination of the dead lever of railway vehicle brake mechanism
an operating rod extending towards the end of the vehicle and serving as a means
of adjusting the said lever to take up slack, and a rack and pawl compensating
device for retaining the lever in its successive positions of advancement, one of the
elements of the said device being hung to the lever, substantially as herein before
described.
Fourth. The combination of the dead lever of railway vehicle brake mechanism
a rack and pawl compensating device for retaining the said dead lever in its
successive positions of advancement one element of the said device being hung to
the dead lever, and a momentum weight serving to aid the take-up movements of
the lever and to prevent rapid reversing of the same substantially as hereinbefore
described.
Fifth. The combination of the dead lever of railway vehicle brake mechanism
an operating rod extending towards the end of the vehicle and serving as a means
of adjusting said lever to take up slack, a weight mounted upon the said rod, and a
rack and pawl compensating device for retaining the lever in its successive positions
of advancement, one of the elements of the said device being hung to the lever,
substantially as hereinbefore described.
Sixth. The combination of the dead lever of railway vehicle brake mechanism, a
rack and pawl compensating device for retaining the said dead lever in its successive
positions of advancement, one element of the said device being hung to the dead
lever by a slotted connection and an operating rod connected to the dead lever
independently of the said element of the compensating device substantially as
herein before described.
Seventh. The combination of the dead lever of railway vehicle brake mechanism,
a rack and pawl compensating device for retaining the said dead lever in its
successive positions of advancement, one of the elements of the said device being
hung to the dead lever by a slotted connection, and an operating rod connected to
the dead lever independently of the said element of the compensating device, the
said rod having a weight mounted upon it substantially as hereinbefore described.
Eighth. The combination of the dead lever of railway vehicle brake mechanism,
a rack hung to the free end of the said dead lever and a guide for the said lever,
the said guide having at its outer end a pawl tooth for engaging with the teeth of
the rack, substantially as hereinbefore described.
Ninth. The combination of the dead lever of railway vehicle brake mechanism, a
rack hung to the lever, and a guide for the said lever having at the outer end a
pawl tooth for engaging with the teeth of the rack and a yoke carrying a spring
which presses upon the rack and holds it in engagement with the pawl tooth,
substantially as herein before described.
Dated this 6th day of October 1892.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, Agents.