IMPROVEMENTS IN SELF-ACTING RAILWAY BRAKES
Year: 1881

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of "IMPROVEMENTS
IN SELF-ACTING RAILWAY BRAKES." A communication from abroad by
John Van Dussen Reed, of the City, County, and State of New York, United
States of America.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 10th August 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN SELF-ACTING RAILWAY BRAKES." [A com-
munication from abroad by John Van Dussen Reed, of the City, County, and
State of New York, United States of America.]
.
This Invention relates to automatic railway brakes. The improvements about
to be described are applicable in great measure to automatic brakes in general, but
are here described as adapted to the automatic double acting system set forth in
former Letters Patent granted to the said Alexander Melville Clark, dated
August 14, 1880, No. 3305.
This automatic brake is one of that class in which the brake chain is wound
upon the brake shaft at required times by friction rollers (one upon the wheel axle
and one upon the brake shaft) being brought into contact one with the other by
the motion of the draw bar. In brakes of this class difficulty has been experienced
in causing the chain to be unwound from the brake shaft when the brake is
released without the use of strong springs to withdraw the brake shoes from the
wheels, and these stiff springs take so much from the power of the hand
brake when it is necessary to use it that they are objectionable upon that
account.
This Invention has first for its object to provide a spring that shall act upon the
automatic brake shaft and cause the chain to be unwound whenever the brake is
released without interfering in any way with the action of the hand brake. This
I accomplish by combining with the automatic brake mechanism a spring (termed
by me a throw-off spring), which is put under tension when the brake is applied,'

page_text: and which is attached to or connected with the automatic brake mechanism at
some point intermediate between the device that imparts power to the automatic
brake mechanism and the point at which the hand brake rod is attached to tho
brake mechanism under such an arrangement that it will act only upon the
automatic brake applying mechanism and not upon the hand brake connections.
The Invention further relates to means for limiting the amount of brake power
that is automatically applied, and to this end it consists in combining with the
automatic brake applying mechanism a spring, which when the strain upon the
brakes exceeds a certain limit will yield to permit the separation of communicating
parts of said mechanism far enough to prevent the transmission of further power
to the brakes while at the same time keeping the brakes applied.
The Invention consists further in various details of construction and arrangement
to be hereafter explained.
The car frame, the draw bar, the draw timbers, the bogie truck frame, the wheels
and axles, the hand brake, and the safety beams, are all similar to those already in
use, and a centrifugal, or more properly a gravity arrangement, similar in its
action to those described in the previous Letters Patent above referred to is
employed.
This improved brake consists of an upper brake shaft having a bearing at one
end in the draw timber and at the other in the car frame; upon the end of this
shaft nearest to the draw timber is a flanged pulley, and a chain attached to and
wound once or twice about its periphery reaches down and is connected to the side
of a friction pulley upon another brake shaft, hereafter referred to as the lower
brake shaft. Another chain is fastened to the side of the first pulley and is
fastened to the end of the equalising lever at the same place as the hand brake
rod. A spring (the throw-off spring hereinbefore referred to) is coiled loosely about
the upper brake shaft, and one end is fastened to the car frame and the other to
the shaft in such a way that it is wound up or tightened when the chain is wound
upon the shaft, and unwound when the chain is unwound. The other or lower
brake shaft is parallel to one of the axles and has a bearing at either end in castings
fastened to the safety beams. This shaft carries the friction pulley above mentioned,
and 'there is another friction pulley clamped upon the axle directly opposite to it.
The casting supporting one end of this brake shaft is bolted to one of the safety
beams and the shaft enters an oblong curved recess near the bottom of the casting;
it also passes through a bearing and a link, the link being pivoted to the casting
in such manner that when the shaft is raised the link will cause the end of shaft to
follow in the curved recess. This link when in its lowest position rests upon a
shoulder upon the casting. A shoulder on the bearing rests upon this link, and
the hole through the bearing is large enough to allow the shaft to pass through it
without coming into forcible contact with its sides, so that as the bearing is pressed
downward by what I call the relief spring, which is confined between the shoulder
of the bearing and a screw adjusted cap, the bearing will not rest directly upon the
shaft but will impart its downward pressure to the erid of the shaft through the
medium of the link. The other end of this brake shaft enters an oblong recess in
the other casting, the said casting being bolted to the other safety beam. In a
curved guide, slot, or recess in one end of this casting an oscillating casting fits
loosely, a flange of the latter entering the recess of the former, and the end of a
sliding pin that passes through a boss on the casting rests against the inner edge
of the flange in such position that a stop piece on the oscillating casting will cross
its path when movement is given to the latter casting. The end of the shaft
passes through an opening in the oscillating casting and forms a support therefor.
A vertical lever is placed directly against the oscillating casting, the shaft also
passing through it, and two studs fastened in the lever pass loosely through slots
in the oscillating casting and serve to maintain the lever in its position. A spring
placed between this lever and the casting tends to keep the lever back with the
said studs against the rear ends of the slots.
The sliding pin above referred to is made to slide in and out by the gravity or

page_text: centrifugal arrangement as hereafter described; when it is out it allows the casting
to partake of whatever motion the lever may have; but when it is in it obstructs
the passage of the stop piece and causes the lever to make one or the other of the
studs its fulcrum according to the direction of the lever's movement, and to apply
a forward movement to the lower brake shaft. A movement of the lever in either
direction produces a like effect upon the end of the lower brake shaft, that is, if the
upper end of the lever is moved forward after the movement in corresponding
direction of the oscillating casting is stopped by the sliding pin, the lower stud
becomes the fulcrum, and when the lever is moved backward and the like
movement of the casting is prohibited by the sliding pin, the upper stud becomes
the fulcrum, but in either case the result is the same and the shaft is pressed
forward.
The gravity or centrifugal arrangement is similar in principle and action, though
of a modified form, to that described in the former 'Letters Patent before referred to.
I now employ preferably two weights or wheels that slide freely upon radial arms
between the boss, to which arms are fixed, and collars at the ends of the arms
provided with springs which serve to cushion the blow of the falling weights upon
the end of the arms. I prefer to clamp this arrangement upon a different axle of
the same truck from that upon which the friction drum is clamped.
A casting bolted to a safety beam has two lugs at its lower extremities, and a
fork has lugs upon it to correspond to the said lugs, and a pin passes through the
two upon one side, and a rod through the two at the other, forming a working
point. A cam is fixed to this fork at a proper height to allow the weights to pass
clear of it when thrown out by centrifugal force, but to be in their pathway when-
ever they shall have fallen a certain distance toward the centre before they come
into contact with it. When the cam is in the pathway of the wheel weights it is
pressed backward by them.
It should be understood that this mechanism does not depend entirely upon
centrifugal force to operate it, as it is more properly a gravity arrangement, and
the speed at which it may be made to operate depends upon the shape and size of
the wheels and cam, and not upon the centrifugal force. As, for instance, if the
wheels be large and the cam long, the axlo must revolve at a very low speed (so
low as to almost entirely overcome centrifugal force) to give the weight sufficient
time to slide in upon the arm after the arm leaves a horizontal position and before
the weight reaches the cam; if it has not time the weight will fall upon the top of
the cam and will slide over it without forcing it back. In this case the only
advantage of centrifugal force is that it renders the action noiseless. A hookerl
stop piece reaches out from the safety beam and limits the forward movement of
the fork. The rod passes freely through the lug of casting, but is keyed to the
fork. A piece having two arms is keyed to the said rod, one of these arms is
weighted and serves to hold the fork forward, and from the other an arm reaches
out to the sliding pin before described and passes through it, the whole forming a
connection by means of which the weights are made to draw the pin at desired
times, and by which said pin is forced in again when the weights are not operating.
A horizontal lever at about the level of the tops of the safety beams is pivoted at
one end, and connected by a slot at the other end to the upper end of the vertical
lever previously referred to. The horizontal lever has a slot at its centre curved to
a radius, of which the centre pin or king bolt of the truck forms the centre. In
said slot is the lower end of another vertical lever, which is supported between the
draw timbers by an arm jointed to it and reaching out from the rear of the draw
bar. The upper end of the lever is forked and straddles a fixed rod, and is held
between spiral springs, nuts, and collars upon the rod, so that the lever is about
vertical when no pressure is exerted upon the draw bar. The springs, one or the
other, compress to admit of a forward or backward movement of the draw bar that
hall exceed the amount required at the lower end of the lever to actuate the brake
movement. One spring is usually made to serve the purpose, for which, for
convenience of illustration, I have described the two hore:

page_text: i
Having now described the different parts of this improved brake, I will next
proceed to describe the method of its operation.
We will suppose that at the present time the car is at rest, but that it is about
to be pulled forward; to do this the draw bar must be drawn upon sufficient to
compress the draw spring slightly. This will draw upon the upright lever just!
described, and cause its lower end to be thrown forward against the front of the
slot in the horizontal lever, and this latter will then be pushed forward and carry
with it the top of the vertical lever, which imparts motion to the oscillating casting,
which, if the sliding pin be withdrawn, will be carried about enough to allow
the pin to fall below the stop piece when it enters. If the pin should not be
withdrawn the stop piece will come against it, and there remain until the axle has
made not to exceed one balf a revolution, when the pin must be withdrawn by the
action of the weights on the cam and allow the stop piece to pass. The pin will
continue to draw and fall back so long as the speed of train does not exceed the
limit at which the weights are set to operate, say about one mile an hour. When 1
the speed shall exceed that, the pin will enter below the stop piece, and the brake
mechanism is in readiness to act whenever the draw bars shall receive an inward
thrust. Now if a brake be applied to the engine or to the cars in advance of this
one, the draw bar will receive such a thrust, and the result will be that the three
several levers just referred to will be forced back. The oscillating casting will
partake of the motion of the lever until the stop piece strikes the sliding pin when
the upper stud will become a fulcrum, and the end of the lower brake shaft
will be pressed forward sufficiently to bring the friction pulleys into contact, and
cause the revolving motion of the axle to be imparted to the said brake shaft.
This will cause the chain to be wound up on the said shaft, quite fast at first, in
consequence of the chain being fastened near the rim of the pulley, and slowly
afterward, when it winds upon the shaft itself. This will continue until the
requisite pull upon the other chain connected to the equalising lever is obtained
when a further strain will overcome the pressure of the relief spring against the
link, and will allow the lower shaft to rise. As the shaft rises the link draws it
backward, and causes the pulleys to be drawn apart sufficiently to stop any
greater pulling upon the chain. It will be seen that by these means the tension
of the relief spring is made to perfectly control the amount of brake power
obtained. As the chain is wound upon the slower shaft, it is unwound from the
pulley upon the upper shaft, and the other chain is wound upon the upper shaft,
fast at first and slower afterward. This chain pulls directly upon the equalising
lever and applies the brake in the same manner as the hand brake. While this
chain is being wound up the throw off spring upon the shaft is being tightened,
so that when the brake is applied, the said spring applies considerable power to
the shaft.
The brake is now applied and will continue so until either the inward pressure
upon the draw bar is relieved, or until the speed of the train is sufficiently reduced
to allow the weights to draw the sliding pin. When from either of these causes
the friction pulleys are allowed to separate, the chain will immediately unwind by
reason of the great strain upon it, assisted by the throw off spring upon the upper
shaft. The chains being fastened to the pulleys at a distance from the centre
renders it easier for the chains to unwind when the force is nearly expended.
The action of the throw off spring and the manner of fastening the chains have
been found to obviate a difficulty that could not be otherwise satisfactorily over-
come in brakes of this class, viz., the tendency of the brake to only partially
release itself. If the train is backed, the draw bar will be pushed in when the
train starts, and the levers will partake of this movement, and the pin will fall in
above the stop piece, and the mechanism will be so adjusted that an outward pull
upon the draw-bar will apply the brake in precisely the same manner as an
inward thrust when the car had been started by a pull upon the draw-bar instead
of the push that it required to shut it in this instance, except that now the lower
stud will act as the fulcrum. It is obvious that the action of the draw-bar

page_text: upon the brake will be the same whether it is at the forward or the rear end of
the car, and that but one set of mechanism is required; but if desired, the
connection may be made with the draw-bar at the other end of the car in such
manner and by such modification of the parts that a pull upon that draw-bar will
cause the upper end of the lever to be thrown back, at the same time as the draw-
bar at this end causes the lower end to be thrown forward, and the motion of the
lever will be thereby increased.
The relief spring may be a helical spring, or may be similar to a clock spring.
The described brake arrangement may be made single acting, that is, to operate
only when the car receives its momentum by a pull upon the draw-bar by
resisting the forward movement of the horizontal lever to a degree that shall allow
the sliding pin to drop below the stop pin when the lever is drawn forward as the
train starts, but without sufficient motion to bring the friction pulleys into contact
when the sliding pin is upon the upper side of the stop piece.
I do not restrict myself to the exact construction of the relief arrangement
consisting of a spring bearing and link, as described, for it is manifest that the
spring may be otherwise applied for the purpose of limiting the amount of brake
power.
I remark also that I do not restrict myself to the particular arrangement of the
throw off spring. It is manifest that it may be applied at various points in the
automatic brake mechanism between the point at which the hand brake is con-
nected and the lower brake or friction roller shaft, the essential feature being that
it shall act, in the manner herein before indicated, on the automatic brake applying
mechanism without influencing or offering any obstacle to the application of the
hand brake. By connecting, in the manner described, the chains to their respective
pulleys, these chains will be wound up more rapidly at the time when less power
is required for the operation, and afterwards less rapidly but with greater power, in
this way increasing the efficiency of the brake applying mechanism. Hooks or
lugs or irregular shaped pulleys may be used to take up the chains faster at the
first, and thereby serve the same purpose as fastening the chains away from the
centre.
A continuous chain running from a small grooved pulley upon the lower brake
shaft to a similar larger one upon the upper shaft may be employed instead of the
single chain, as described.
I will now describe a modification of the above described mechanism. In
common with the said mechanism the one about to be described contains a friction
pulley shaft movable to and from the car axle, and provided with a relief spring
which yields to permit the separation of the shaft and axle when the strain on the
brakes exceed the prescribed limit; also an upper brake or winding shaft combined
with a throw-off spring which is put under tension when the automatic brake
mechanism is applying the brakes. I also make use of a centrifugal or gravity
mechanisin for operating at required times the device which disconnects the friction
pulley shaft from the mechanism by which it is forced towards and into engage-
ment with the car axle, said centrifugal or gravity mechanism being similar in
principle and general mode of operation to that before described, but differing
therefrom in construction and arrangement.
The present improvements principally relate to the devices whereby the instrú-
mentalities for moving the-friction pulley shaft to and from the axle are thrown
into and out of operative connection with the mechanism, which is caused to act
on the same by the movement of the draw-bar, the object being to reduce the
number of and simplify the parts, and obtain a nechanism which, while entirely
effective, shall be free from complication and not liable to get out of order. The
lower brake shaft upon which the friction pulley is fixed is supported in end
bearings which are elongated to permit the shaft to be moved to and from the
adjoining axle, so as to bring at required times its pulley into contact with the
friction drum on the axle.
In the one bearing the shaft is received in a box movable in the bearing, and

page_text: combined with a relief spring which permits the shaft to recede from the axle
when the strain on the brakes becomes excessive. The shaft is connected to the
upper brake or winding shaft by a chain attached to the side of the friction pulley,
and to a drum fast on the upper shaft, around which drum the chain passes once
or twice. The upper shaft is supported in proper bearings at one end in the draw
timber and at the other end in the car frame, and is combined with a throw off
spring which is put under tension when the shaft is rotated to apply the brakes,
and acts when the brakes are to be taken off to assist in unwinding the chain.
The parts above described in their general arrangement and mode of operation
resemble the like parts of the automatic brake mechanism previously described;
they require therefore no special description here.
Within
I now proceed to describe the instrumentalities whereby the friction pulley shaft
is at stated times thrown into and out of operative connection with the car axle
which carries the friction drum. The friction drum, which is hollow, is made in halves,
which are clamped upon the axle. The space within the drum communicates with
the outside only through a narrow annular slot in one side of the drum.
the drum is placed the contrifugal arrangement which consists of preferably four
wheel weights, which can slide in or out upon radial studs which extend through
and from the inner hub of the drum to and through the outer circumference of
the drum. A shoulder upon each of the studs prevent it from slipping outwardly,
and when the drum is clamped upon the axles the inner end of the stud rests
against the axle and is thereby prevented from slipping inwardly. The action and
purpose of these wheel weights are similar to those before described to auto-
matically destroy working connection between the draw-bar and its attached
mechanism, and the brake applying mechanism when the car is moving very slowly,
and to allow it to be established when the train moves at a greater speed. The
hub of the drum is elongated upon that side of the drum in which the opening is,
and is formed with a wide peripheral groove. To a transom of the truckframo
is bolted a bracket which supports a curved lever secured in place by a bolt
passing loosely through its rear end in such a way as to hold the lever in position
without preventing it from rocking. The lever is curved at about its centre and
nearly balanced, so that it will rock upon the upper surface of the arm on which
it rests.
The front end of the lever is bent horizontally to a right angle and bevelled, and
this end projects into the interior of the friction drum through the annular slot
and extends into the plane of revolution of the wheel weights, so that the lever
will be pushed by the wheel weights whenever the axle revolves slowly enough to
allow the latter to fall toward the axle before reaching the bevelled end of the
lever. The lateral vibration of the lever is limited by a stop piece or plate
preferably of hardened steel) of proper size rivetted to the under side of the lever
and resting in the groove. The lever is designed to act on a sliding locking cross
pin, which, at one ond, is received in a horizontally elongated bearing, and at the
other end passes through a strap or loop like bearing piece on the under side of
the horizontal arm of the bracket. The pin has a spiral spring upon it by which
it is normally held in a position where it will extend across a narrow longitudinal
slot formed in the front portion of the horizontal arm of the bracket, and it is
moved in the opposite direction by means of the lever, which is provided with a
shoulder that bears laterally against a collar on the pin. The pin, by means of a
hook like link, is connected with the friction pulley shaft, so that the two shall
move together when the pin is moved back and forth longitudinally of the car, the
link being constructed so that it may be hooked upon or unhooked from the pin at
pleasure, its hook end lying between two collars on the pin. This movement of
the pin causes the shaft to be drawn towards the axle, and is effected through the
intermediary of a vertical lever which is connected with the draw-bar, and projects
through the slot in the bracket, and when in operative position extends down
behind the pin. When the parts are in this position, if the vertical lever be
vibrated in a direction to throw its lower end forward, this end will bear against

page_text: the pin and press it forward also; and through the intermediary of the link
similar movement will be imparted to the friction pulley shaft, which will thus bo
drawn towards the car axle and friction drum thereon. When, on the other hand,
the pin, by the action of the curved lever, is pushed back from across the slot,
operative connection between the vertical lever and the pin is destroyed, and the
lever ceases to affect the friction pulley shaft. The manner of connecting the vertical
lever, which, for convenience sake, I will term the draw-bar-lever, with the draw-bar
is as follows:-To the rear of the draw-bar is loosely connected by means of the draw-
bar bolt an L shaped strap or bar having at its rear end a hole or opening so as to
loosely encircle the upper end of the vertical lever. Vertically beneath this bar and
below the draw-bar timbers I arrange another bar, which is a slide bar, supported in
bearings formed the one in the turned down loop of a U shaped piece secured to
the under side of the draw-bar timbers in the place usually occupied by the "draw-
bar guides," and the other in a bridge piece fastened to the underside of said
U shaped piece. The slide bar is also formed at its rear with a hole or opening, so
as to also encircle the vertical lever. The sliding movement of the latter bar is
subject to the control of springs, which encircle it between its bearings, and aro
separated by a central pin or shoulder on the bar. The spring in front is light,
and the spring in rear is heavy, so that a backward movement of the bar will
compress the heavy spring, and a forward movement of the bar will compress the
light spring. Each bar at the point where the opening in it is formed for the
passage of the vertical lever has a notch, and on the vertical lever is a corresponding
spline or feather, which at two points at which the lever when in position meets
the bars is cut away. In putting the lever in place it is pushed upward through
the openings in the bars, its feather registering with the notches. As soon as it is
in place it is turned so as to carry its feather out of register with the notches, and
is thus held securely in position. The connections between the L shaped bar and
the draw-bar, and between the two bars and the lever, should be free enough to
allow the lever all needed latitude of movement. The mode of operation is as
follows: When the train first starts (supposing it to be drawn) the draw-bar will
be drawn forward, carrying with it the connecting strap and the upper end of the
vertical draw-bar lever; the lower end of the said lever will consequently be
thrown backward in the slot in the bracket, the slide bar acting as a fulcrum.
While the car is moving very slowly the spring pin will be forced out frequently
by the action of the centrifugal weights upon the curved lever, and by the action
of this lever in turn upon the spring pin, and will thus be disengaged from the
vertical draw-bar lever. As soon however as the speed of the axle becomes
sufficient to prevent the centrifugal weights from acting upon the curved lever, the
spring pin will be forced inward by its spring, and its end will project across the
slot in front of the draw-bar-lever. Now if a brake be applied to the locomotive,
or to any one car in the train ahead of the one having this brake upon it, the
draw-bar will be forced backward, and this will cause the lower end of the draw-
bar-lever to be thrown forward, and that will carry with it the end of the spring
pin in front of it, and that in its turn will draw the friction pulley shaft forward
until its pulley or drum and the drum upon the axle are brought into contact, and
the brake applied in a manner similar to that before described. When the train is
again nearly at a standstill, the centrifugal weights will act upon the curved lever
to cause the spring pin to be withdrawn and disengaged from the draw-bar-lever,
thereby allowing the friction pulleys on the shaft and axle to become separated
and the brake to be released. If when the train is started it is pushed instead of
being drawn, the draw-bar will be forced backward, and the lower end of tho
draw-bar-lever will consequently be thrown forward, so that when the centrifugal
arrangement ceases acting on the spring pin, the end of the pin will be forced
across the slot behind the draw-bar-lever. Under these circumstances any further
forcing in of the draw-bar will only cause the draw-bar-lever to be forced against
the forward end of the slot, while an outward pull upon the draw-bar will cause
the said lever to be thrown back against the spring pin; but inasmuch as the

page_text: latter cannot move back of the longitudinal centre of the slot, the operation will
have no effect upon the brake. By making the loop like bearing piece long
enough to allow the pin to travel the full length of the slot, and by placing the
Bupport or fulcrum near the centre of the pin instead of at the end, and by the use
of two of the connecting links, one upon each side of the support, the brake may
be made double acting, that is, to cause a pushing in of the draw-bar to apply the
brake when the train was started by drawing, or to cause a drawing out of the
draw-bar to apply the brake when the train was started by pushing in a many
similar to the brakes described in my Letters Patent herein before referred to.
The spring locking pin can be actuated by means other than the curved lever.
The bracket in this arrangement is a simple L shaped piece having its vertical arın
fastened to the transom. The curved lever is dispensed with and while the friction
drum and centrifugal gravity mechanism are as before carried on the axle, the
drum is a plain one, made in two parts, clamped on the axle and provided with
prolongations which carry the wheel weights and their radial guide studs or
rods which are exposed and not housed within the drum, the collars at the outer
ends of the studs being enlarged to prevent any possibility of the studs catching
the brake chains. The sliding spring pin in this case is operated by the action of
the wheel weights upon a vibratory lever jointed to an L shaped connecting rod or
bar whose upright arm encircles the spring pin between two collars thereon. The
lever is forked so as to straddle the axle, and is pivoted to a supporting bracket.
One of the arms of the forked lever is prolonged before the pivot, and to this
prolongation the connecting bar is jointed. The lever is provided with a cam
which normally projects into the plane of revolution of the wheel weights, so that
when the axle revolves slowly enough to permit the wheel weights to drop toward
the centre before reaching the cam, the lever will, by the action of the weights on
the cam, be pushed back, with the result of pushing back the spring pin from across
the slot in the bracket.
I will now describe an arrangement of the relief spring, by means of which the
power of the brake may be varied to correspond with the load carried by the car.
The spring box for the friction wheel shaft and the bearing piece are like those
herein before described. Upon the top of the spring rests the head of a rod which
extends up through the top of the spring box, and is loosely jointed to a lever
pivoted to the bearing piece, and at its other end hinged to a shaft or bar attached
to the bolster or some other part of the car frame which has the motion of the car
springs between it and the truck frame to which the relief spring arrangement is
fastened. Under this arrangement, as the car body settles upon its springs under
the load placed upon it, proportionate pressure will, through the intermediary of
the instrumentalities just described, be applied to the upper end of the relief spring,
so that a greater strain on the brake chain will be required to lift the friction
wheel shaft and its box when the car is heavily loaded than when it is light. The
motion given by the operation of the springs between the axle journal boxes and
the truck may be employed also to operate the arrangement just described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the.
10th February 1882.
!
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"IMPROVEMENTS IN SELFACTING RAILWAY BRAKES." A com-
munication from abroad by John Van Dussen Reed, of the City, County, and
State of New York, United States of America.
This Invention relates to automatic railway brakes, and has been designed for
carriages or vehicles in which the draw bar and its couplings are so constructed
that the draw bar will receive an inward thrust when the speed of the engine is
suddenly reduced. The improvements about to be described are applicable in
great measure to automatic brakes in general, but are herein described and shown
as adapted to the automatic double acting system set forth in former Letters Patent,
granted to me the said Alexander Melville Clark, dated August 14th 1880,
No. 3305.
This automatic brake is one of that class in which the brake chain is caused to
be wound upon the brake shaft at required times by friction rollers (one upon the
wheel axle and one upon the brake shaft) being brought into contact one with the
other by the motion of the draw bar. In brakes of this class difficulty has been
experienced in causing the chain to be unwound from the brake shaft when the
brake is released, without the use of strong springs to withdraw the brake shoes
from the wheels, and these stiff springs take so much from the power of the hand
brake when it is necessary to use it that they are objectionable upon that account.
This Invention has first for its object to provide a spring that shall act upon
the automatic brake shaft and cause the chain to be unwound whenever the brake
is released, without interfering in any way with the action of the hand brake.
This is accomplished by combining with the automatic brake mechanism a spring
(herein termed a throw-off spring) which is put under tension when the brake is
applied, and which is attached to or connected with the automatic brake mechanism
at some point intermediate between the device that imparts power to the automatic
brake mechanism and the point at which the hand brake rod is attached to the
brake mechanism, the arrangement being such that this throw-off spring will act
only upon the automatic brake applying mechanism, and not upon the hand brake
connections.
The Invention further relates to means for limiting the amount of brake power
that is automatically applied, and to this end it consists in combining with the
automatic brake applying mechanism a spring, which when the strain upon the
brakes exceeds a certain limit will yield, to permit the separation of the cominuni-
cating parts of the said mechanism far enough to prevent the transmission of
further power to the brakes while at the same time keeping the brakes applied.
The Invention consists further in various details of construction and arrange-
ment to be hereafter explained.
In order that the Invention may be more readily understood, I will proceed to
describe it with reference to the accompanying Drawings, in which Figure 1 is a
longitudinal central section of as much of a car or carriage on the bogie system as is
necessary to explain the Invention; Figure 2 is a plan of the same parts in section,
the carriage framing being removed in order to more clearly show the brake
applying mechanism; Figure 3 is a plan of the front portion of one of the bogies;
Figure 4 is a vertical section of the same; Figure 5 is a transverse vertical section
partly in elevation of the front portion of the bogie and carriage framing in
Figure 1; Figure 6 is a similar section through the rear portion of the same bogie;
Figure 7 is an elevation partly in section showing the arrangement of the movable

page_text: casting T and lever n hereinafter referred to; Figures 8, 9, 10, 11, and 12, are
detail views representing the casting S and parts immediately connected with it;
Figures 13 and 14 are like views of the casting T; Figures 15 and 16 are an
elevation and plan respectively of the bracket which receives the casting T;
Figures 17, 18, and 19, are detail views of the centrifugal or gravity mechanism;
Figures 20, 21, and 22, are views of modifications hereinafter referred to. The
same letters of reference indicate the same parts in Figures 1 to 22.
The car frame A, the draw bar B, the draw timbers C, the bogie truck frame D,
the wheels G, and axles E, the hand brake F, and the safety beams H, are all
similar to those already in use, and a centrifugal, or more properly a gravity
arrangement I, similar in its action to those described in the previous Letters
Patent above referred to, is employed.
This improved brake consists of an upper shaft J, having a bearing at one end
in the draw timber C, and at the other in the car frame A; upon the end of this
shaft nearest to the draw timber there is a flanged pulley K; and a chain L,
attached to and wound once or twice about the periphery of this pulley, reaches
down and is connected to an eye bolt in the side of a friction pulley M. upon another
shaft R. Another chain N is fastened to the side of the pulley K and is fastened
to the end of the equalising lever O at the same place as the hand brake rod F.
A spring P (the throw-off spring herein before referred to) is coiled loosely about
the shaft J, as shown in Figure 3, and one end is fastened to the car frame A and
the other to the shaft itself in such way that it is wound up or tightened when
the chain is wound upon the shaft, and unwound when the chain is unwound.
The lower shaft R is parallel to one of the axles E, and has a bearing at either end
in brackets or castings S, S¹, fastened to the safety beams H. This shaft carries
the friction pulley M above mentioned, and there is another friction pulley M³
clamped upon the axle E directly opposite to it. The casting S supporting one
end of this shaft R (see detail views, Figures 8, 9, 10, 11, 12,) is bolted to one of
the safety beams H, and the shaft enters a curved recess a near the bottom of the
casting; it also passes through a bearing b and a link c, the link being pivoted
at c¹ to the casting S in such manner that when the shaft is raised the link will
cause the end of the shaft to follow in the curved recess a. This link c when in
its lowest position rests upon a shoulder d upon the casting S. A shoulder e on
the bearing b rests upon this link c, and the hole through the bearing is large
enough to allow the shaft to pass through it without coming into forcible
contact with its sides, so that as the bearing is pressed downward by what
I call the relief spring f(see Figures 1 and 5), which fits over the stem b¹, and is
confined between the shoulder e of the bearing and a cap f1 adjusted by a set
screw, the bearing will not rest directly upon the shaft, but will impart its
downward pressure to the end of the shaft through the medium of the link. The
other end of this shaft R enters an oblong recess h in the other casting S (see
Figures 15 and 16), the said casting being bolted to the other safety beam. In a
curved guide slot or recess I in one end of this casting the correspondingly curved
flange on the end of an oscillating casting T fits loosely, and the end of a sliding
pink that passes through a boss on the casting S¹ (see Figures 7, 15, and 16),
rests against the inner edge of the flange j in such position, that it will cross the
path of a stop piece k¹ on the casting T when the latter is oscillated. The end of
the shaft R passes through an opening m in the casting T, and forms a support
therefor. A vertical lever n is placed directly against the casting T, the shaft R
also passing through it (see Figure 7), and two studs o fixed to the lever pass
loosely through slots p in the casting T, and having heads o' (see Figure 5) at the
back of the casting serve to maintain the lever n in its position. A spring r
placed between this lever n and the casting T tends to keep the lever back with
the said studs o against the rear ends of the slots p. Tho pin k (Figure 7) is made to
slide in and out by the gravity or centrifugal arrangement, as hereafter described.
When the pin is out, it allows the casting T to partake of whatever motion the
lever n may have, but when it is in it obstructs the passage of the stop piece k¹, and

page_text: causes the lever n to make one or the other of the studs o its fulcrum, according to
the direction of the lever's movement, and to apply a forward movement to the
lower brake shaft, the spring r being compressed. A movement of the lever n in
either direction produces a like effect upon the end of the shaft R, that is to say, if
the upper end of the lever n is moved forward after the movement in corresponding
direction of the casting T is stopped by the sliding pin k, the lower stud o becomes
the fulcrum, and when the lever n is moved backward and the like movement of
the casting T is prohibited by the sliding pin k, the upper stud o becomes the
fulcrum, but in either case the result is the same, and the shaft R is pressed
forward.
The gravity or centrifugal arrangement is similar in principle and action, though
of a modified form to that described in the former Letters Patent before referred to.
I now employ by preference two weights or rollers 1 (see Figures 1, 6, 17, 18,
and 19), that slide freely upon their respective radial arms 2 between the boss 3 to
which the arms are fixed, and collars 4 at the ends of the arms provided with
springs 5, which serve to cushion the blow of the falling weights upon the end of
the arms.
I prefer to clamp this arrangement upon a different axle E of the same
bogie from that upon which the friction drum M is mounted. A casting V bolted
to one of the safety beams has two lugs ¹ (Figures 1, 17, 18, and 19), at its lower
extremities, and a fork W has lugs upon it to correspond to the lugs r¹, and a pin s
passes through the two upon one side, and a shaft t through the two at the other
forming a working point. A cam v is fixed to this fork W at a proper height to
allow the weights 1 to pass clear of it when thrown out by centrifugal force, but
to be in their pathway whenever they shall have fallen a certain distance inwards
toward the centre before arriving opposite to it. When the cam is in the path-
way of the roller weights it is pressed backward by them. It should be understood
that this mechanism does not depend entirely upon centrifugal force to operate it,
as it is more properly a gravity arrangement, and the speed at which it may be
made to operate depends upon the shape and size of the rollers and cam, and not upon
the centrifugal force. For instance, if the rollers be large and the cam long, the axle
must revolve at a very low speed to give the weight sufficient time to slide in upon
the arm after the arm leaves a horizontal position, and before the weight reaches
the cain; if it has not time to do so, the weight will fall upon the top of the cam
and will slide over it without forcing it back. In this case the only advantage of
centrifugal force is that it renders the action noiseless. A catch V' reaches out from
the safety beam and limits the forward movement of the fork W. The shaft t passes
freely through the lug ¹ of casting V, but is keyed to the fork W, and its other
end rests in the bearing g of the casting S (Figures 1, 8, and 9). A two armed
piece w, w (Figures 1, 4, and 5) is keyed to the shaft t, and one of its arms w¹ is
weighted and serves to hold the fork W forward, and the other arm w is connected
by a link to the sliding pin k, which has a hole in which the hooked end of said
link is inserted, the whole forming a connection by means of which the weights 1
are made to draw the pin k at desired times, and by which said pin is forced in
again when the weights are not operating. A horizontal lever X (Figures 2, 3, 5, 7,)
reaches from the casting S to the lever n at about the level of the tops of the
safety beams. It is pivoted at one end on the set screw f³, and has a slot a¹ at the
other end through which the upper end of the vertical lever passes, the latter
being reduced in size so as to forin shoulders for the lever X to rest upon, as
shown in Figure 7. A pin n' passed through a hole in the lever n just above the
lever X prevents the latter rising. The horizontal lever ✗ has a longitudinal
slot at its centre, curved to a radius of which the centre pin or king bolt of the
bogie truck forms the centre so as not to interfere with the swivelling motion of
the bogie. Another vertical lever Y is supported between the draw timbers by an
arm Breaching out from the rear of the draw bar B, in the forked end of which
arm the lever Y is pivoted at y. The lower end of this lever enters the slot as of
horizontal lover ✗, and the upper end is forked and straddles a fixed rod y³
fastened at one or both ends.to.the draw timbers. The upper forked end-of lever Y.

page_text: is held between spiral springs y³, nuts, and collars upon the rod y², so that the
lever Y is about vertical when no pressure is exerted upon the draw bar B. The
one or the other spring y³ compresses to admit of a forward or backward movement
of the draw bar B that shall exceed the amount required at the lower end of the
lever to actuate the brake movement. One spring is usually made to serve the
purpose for which, for convenience of illustration, I have shown the two here.
Having now described the different parts of this improved brake I will next
proceed to describe the method of its operation. We will suppose the car to be at
rest. If now it be drawn forward the draw spring B will be slightly compressed,
the upright lever Y will be drawn forward by the arm B¹ and its lower end will
be pulled forward against the front of the slot a² in the horizontal lever X. This
lever will thereupon be pushed forward and carry with it the top of the upright
lever n, whereby motion is imparted to the oscillating casting T, which, if the
sliding pin k be withdrawn, will be carried about enough to allow the pin k to fall
below the stop piece k¹ when it enters. If the pin should not be withdrawn, the
stop piece will come against it and there remain until the axle has made not
more thon half a revolution, when the pin must be withdrawn by the action of the
weights 1 on the cam and allow the stop piece to pass. The pin will continue
to move in and out so long as the speed of the train does not exceed the limit at
which the weights are set to operate, say, about 1 mile an hour. When the speed
exceeds that, the pin k will enter below the stop piece ¹ and remain, and the
brake mechanism is then in readiness to act whenever the draw bars shall receive
an inward thrust. Now if a brake be applied to the engine or to the cars in
advance of this one the draw bar will receive such a thrust, and the result will be
that the vertical lever Y, the horizontal lever X, and the upper end of the lever n
will be forced back. The oscillating casting T will partake of the motion of the lever n
until the stop piece k strikes the sliding pin k, when the upper stud o will become
a fulcrum, and the end of the shaft R will be pressed forward sufficiently to bring
the friction pulleys M, M¹, which are set a little way apart, into contact, and cause
the revolving motion of the axle to be imparted to the said shaft R. This will
cause the chain L to be wound upon the shaft R, fast at first, in consequence of
the chain being fastened near the rim of the pulley M, and slowly afterward when
it winds upon the shaft itself. This will continue until the requisite pull upon the
other chain N connected to the equalising lever is obtained, when a further strain
will overcome the pressure of the relief spring f against the link c, and will allow the
shaft R to rise. As the shaft R rises, the link c draws it backward and causes the
pulleys M, M³, to be drawn apart sufficiently to stop any greater pulling upon the
chain. It will be seen that by these means the tension of the relief spring fis
made to perfectly control the amount of brake power obtained. As the chain L is
wound upon the shaft R, it is unwound from the pulley K upon the shaft J above,
and the other chain N is wound upon the upper shaft J, fast at first and slower
afterward, as in the case of the chain L. This chain N pulls directly upon the
equalising lever O and applies the brake in the same manner as when hand power
is used. While this chain N is being wound up, the throw-off spring P upon the
shaft J is being tightened, so that when the brake is applied, the said spring P
applies considerable power to the shaft J. The brake is now applied and will
continue so until either the inward pressure upon the draw bar is relieved, or until
the speed of the train is sufficiently reduced to allow the weights I to fall inwards
sufficiently to act on cam v, and thereby cause the withdrawal of the sliding pin k.
When from either of these causes the friction pulleys M, M', are allowed to
separate, the chain N will immediately unwind by reason of the great strain upon
it, assisted by the throw-off spring P upon the upper shaft J. The chains being
fastened to the pulleys at a distance from the centre, renders it easier for the chains
to unwind when the force is nearly expended. The action of the throw-off
spring P and the manner of fastening the chains have been found to obviate a
difficulty that could not be otherwise satisfactorily overcome in brakes of this
class, viz., the tendency of the brake to only partially release itself.

page_text: If the train is backed, the draw bar will be pushed in when the train starts, and
the levers will partake of this movement, and the pin k will fall in above the stop
piece k, and the mechanism will be so adjusted that an outward pull upon the
draw bar will apply the brake in precisely the same manner as an inward thrust
caused it to be applied when the car had been started by a pull upon the draw
bar, except that now the lower stud o will act as the fulcrum of the lever n. It is
obvious that the action of the draw bar upon the brake will be the same whether
it is at the forward or the rear end of the car, and that but one set of mechanism
is required, but if desired the connection may be made with the draw bar at the
other end of the car. To do this the rod y', instead of being stationary as in
Figure 1, is free to slide in bearings 3 (see Figure 20) fixed to the draw timbers.
The lever Y is pinned to the rod y² so that the two move together, and either one
or the other of the spiral springs y³ is compressed between one or the other of the
bearings when the lever Y is pushed or drawn. Now if a rod or chain 3 be
attached to the end of this rod y' and to the other draw bar, a pull upon that
draw bar will cause the upper end of the lever to be thrown back at the same
time that the draw bar at this end causes the lower end to be thrown forward, and
the motion of the lever will be thereby increased. It is preferred that one of the
springs should be longer than the other, as shown in Figure 20. The relief®
spring P may be a helical spring, as in Figures 3 and 5, or it may be similar to a
clock spring, as in Figures 21 and 22.
The described brake arrangement may be made single acting (that is, to operate
only when the car receives its momentum by a pull upon the draw bar) by resisting
the forward movement of the horizontal lever X to a degree that shall allow the
sliding pin k to drop below the stop piece when the lever is drawn forward as the
train starts, but without sufficient motion to bring the friction pulleys M, M¹, into
contact when the sliding pin k is upon the upper side of the stop piece k¹.
I do not restrict myself to the exact construction of the relief arrangement
consisting of a spring bearing and link, as described, for it is manifest that the
spring may be otherwise applied for the purpose of limiting the amount of brake
power. I remark also that I do not restrict myself to the particular arrangement
herein shown of the throw off spring. It is manifest that it may be applied at
various points in the automatic brake mechanism between the point O, at which
the hand brake is connected, and the lower shaft R, the essential feature being
that it shall act, in the manner horeinbefore indicated on the automatic brake
applying mechanism without influencing or offering any obstacle to the application
of the hand brake. By connecting in the manner described the chain L to the
pulley M, and the chain N to the drum K, these chains will, as before mentioned,
be wound up more rapidly at the time when less power is required for the
operation, and afterwards less rapidly but with greater power, thus increasing the
efficiency of the brake applying mechanism. Hooks or lugs or irregular shaped
pulleys may be used to take up the chains faster at the first, and thereby serve the
same purpose as fastening the chains away from the centre. Set nuts may be
placed upon the bar connecting the vertical lever Y with the push bar for the
purpose of adjusting the position of the lever, instead of using the nuts upon the
rod y carrying the springs. A continuous chain running from a small grooved
pulley upon the lower shaft R to a similar larger one upon the upper shaft J may
be employed instead of the single chain as described.
I will now describe a modification of the above described mechanism. In
common with the said mechanism that about to be described contains a friction
pulley shaft movable to and from the wheel axle and provided with a relief spring,
which yields to permit the separation of the shaft and axle when the strain on the
brakes exceeds the prescribed limit; also an upper or winding shaft combined with
a throw-off spring, which is put under tension when the automatic brake mechanism
is applying the brakes. I also make use of a centrifugal or gravity mechanism for
operating at required times the device which disconnects the friction pulley shaft
from the mechanism by which it is forced towards and-into engagement with the

page_text: wheel axle, said centrifugal or gravity mechanism being similar in principle and
general mode of operation to that before described, but differing therefrom in
construction and arrangement.
The present improvements principally relate to the devices whereby the
instrumentalities for moving the friction pulley shaft to and from the axle are
thrown into and out of operative connection with the mechanism which is caused
to act on the same by the movement of the draw bar, the object being to simplify
and reduce the number of the parts, and obtain a mechanism which, while entirely
effective, shall be free from complication and not liable to get out of order. I will
proceed to describe these improvements with reference to Figures 23 to 37 of the
accompanying Drawings; Figure 23 is a perspective view of part of a bogie truck;
Figure 24 is a longitudinal section of the same together with the draw bar and
timbers and a portion of the car frame; Figure 25 is a plan of the same; Figure 26
is an elevation; and Figure 27 is a plan on a larger scale of that portion of the
mechanism which operates on the friction pulley shaft; Figure 28 is a sectional
elevation on line x-x, Figure 27; Figures 29 and 30, are longitudinal and transverse
sections respectively of the centrifugal or gravity mechanism; Figure 31 is an
elevation of that bearing for the friction pulley shaft which carries the relief spring;
Figure 32 is an elevation of the other bearing for the said shaft; Figures 33
and 34 represent respectively in perspective and inverted plan those portions of
the mechanism which are connected to the draw bar and draw timbers; Figures 35, 36,
and 37, represent modifications to be hereinafter described. The same letters of
reference indicate the same parts in Figures 23 to 37.
In these Figures, A, are portions of the car frame; B, are the draw timbers;
C is the bogie frame; D, the transom; E, are the safety beams; F, the axles;
G, the wheels; and H, portions of the hand brake mechanism, all of which are of
ordinary or suitable construction; I is the friction pulley shaft upon which is fixed
the friction pulley I', said shaft being supported in end bearing I, I³, (shown more
clearly in Figures 31 and 32) which are elongated to permit the shaft to be moved
to and from the adjoining axle F, so as to bring at required times its pulley I'
into contact with the friction drum F' on the axle. In the bearing 1 the shaft I
is received in a box a, movable in the bearing and combined with a relief spring a¹,
which permits the shaft to recede from the axle when the strain on the brakes
becomes excessive. The shaft I is connected to the upper or winding shaft J by a
chain K attached to the side of the friction pulley I¹ and to a drum J₁ fast on the
shaft J, around which drum the chain passes once or twice. The shaft J is
supported in proper bearings at one end in the draw timber, and at the other end
in the car frame, and is combined with a throw-off spring J' which is put under
tension when the shaft is rotated to apply the brakes, and acts when the brakes are
to be taken off to assist in unwinding the chain L from the shaft. This chain Lis
attached at one end to the side of the drum J¹, and at the other to the equalising
lever M, at the same point at which the hand brake rod H is connected to the
lever. The parts above described in their general arrangement and mode of
operation resemble the like parts of the automatic brake mechanism previously
described. They require therefore no special description here.
I now proceed to describe the instrumentalities whereby the friction pulley
shaft is at stated times thrown into and out of operative connection with the axle
which carries the friction drum. This friction drum, which is hollow, is made in
halves, which are clamped upon the axle, as shown in Figures 29 and 30. The
space within the drum cominunicates with the outside only through a narrow
annular slot 6 in one side of the drum. Within the drum is placed the centrifugal
arrangement which consists of preferably four roller weights c which can slide in
or ont upon radial studs c' which extend through and from the inner hub of the
drum to and through its outer circumference. A shoulder upon each of the studs
prevents it from slipping outwardly, and when the drum is clamped upon the
axles, the inner end of the stud rests against the axle and is thereby prevented
from slipping inwardly. The action and purpose of these roller weights are similar

page_text: to those before described, viz., to automatically destroy working connection
between the draw bar and its attached mechanism, and the brake applying
mechanism when the car is moving very slowly, and to allow it to be established
when the train inoves at a greater speed. The hub of the drum is elongated
upon that side of the drum in which is the opening b, as shown in Figure 29, and
is formed with a wide peripheral groove d. To the transom D is bolted a
bracket N whose lower arm supports a curved lever e, see Figures 24, 25, 20, and 27,
secured in place by a bolt f passing loosely through its rear end in such a way as
to hold the lover in position without preventing it from rocking. The lever is
curved at about its centre and nearly balanced so that it will rock on the upper
surface of the arm on which it rests. The front end of the lever is bent
horizontally to a right angle and bevelled, as shown at e¹ in Figure 27, and this
end projects into the interior of the friction drum F' through the annular slot b,
as shown in Figures 27 and 29, and extends into the plane of revolution of the
roller weights c so that the lever will be pushed by the roller weights whenever
the axle revolves slowly enough to allow them to fall toward the axle before they
reach the bevelled end of the lever. The lateral vibration of the lever is limited
by a stop piece or plate e* (preferably of hardened steel) of proper size rivetted to the
underside of the lever and resting in the groove The lever e is designed to act on
a sliding locking cross pin g which at one end is received in a horizontally elongated
bearing g¹ (Figure 32), and at the other end passes through a strap or loop like
bearing piece g on the underside of the horizontal arm of the bracket N. The pin
has a spiral spring hupon it bearing at one end against plate Is, and at the other
against a collar h¹ shrunk on the pin by which it is normally held in a position where
it will extend across a narrow longitudinal slot i formed in the front portion of the
horizontal arm of the bracket N, and it is moved in the opposite direction by means
of the lever e, which is provided with a shoulder e that bears laterally against a
collar h² on the pin, as shown in Figure 28. The pin by means of a hook like linkj
is connected with the friction pulley shaft I, so that the two shall move together
when the pin is moved back and forth longitudinally of the car, the link being con-
structed, as shown in Figure 20, so that it may be hooked upon or unhooked from the
pin at pleasure, its hook end lying between two collars h³, hs, on the pin. This move-
ment of the pin causes the shaft I to be drawn towards the axle, and is effected
through the intermediary of a vertical lever O which is connected with the draw
bar and has a flattened lower end that projects through the slot i in the bracket N,
and when in operative position extends down behind the pin g. When the parts
are in this position, if the lever O be vibrated in a direction to throw its lower ond
forward, this end will bear against the pin g and press it forward also, and through
the intermediary of the link j similar movement will be imparted to the friction
pulley shaft I, which will thus be drawn towards the axle F. When on the other
hand the pin by the action of the curved lever e is pushed back from across the
slot i, operative connection between the lever O and the pin is destroyed, and
the lever ceases to affect the friction pulley shaft. The manner of connecting the
vertical lever O, which for convenience sake I will term the draw bar lever, with
the draw bar is as follows:-To the rear of the draw bar P is loosely connected by
means of the draw bar bolt k an L shaped strap or bar Z having at its rear end a
hole or opening so as to loosely encircle the upper end of the lever O, as shown in
Figure 33. Vertically beneath this bar and below the draw bar timbers is
arranged another bar m which is a slide bar supported in bearings n formed, the
one in the turned down loop of a U shaped piece o secured to the underside of the
draw bar timbers in the place usually occupied by the draw bar guides, and
the other in a bridge piece o¹ fastened to the underside of the piece o. The slide
bar m is also formed at its rear with a hole or opening so as to also encircle, like
the bar 1, the vertical lever O. The sliding movement of the bar m is subject to
the control of springs p, p¹, which encircle it between its bearings n, and aro
separated by a central pin or shoulder p* on the bar m. The spring p' in front is
light and the spring p in rear is heavy, so that a backward movement of the bar

page_text: .
will compress the heavy spring, and a forward movement of the bar will compress
the light spring. Each bar at the point where the opening in it is formed for the
passage of the vertical lever has a notch r, and on the vertical lever O is a corre-
sponding spline or feathers, which at two points s' at which the lever when in
position meets the bars is cut away, as shown in Figures 24 and 33. In putting
the lever in place it is pushed upward through the openings in the bars, its feather
registering with the notches. As soon as it is in place it is turned so as to carry
its feather out of register with the notches (see Figure 33), and is thus held
securely in position. The connections between the L shaped bar and the draw
bar, and between the two bars and the lever, should be free enough to allow the
lever-all-needed latitude of movement. The mode of operation is as follows:-
When the train first starts (supposing it to be drawn) the draw bar will be drawn
forward carrying with it the connecting strap and the upper end of the vertical
draw bar lever O; the lower end of the said lever will consequently be thrown
backward in the slot i in the bracket N, the slide bar m acting as a fulcrum
and the light spring p' yielding for any excessive amount of motion. While
the car is moving very slowly the spring pin g will be forced out frequently
by the action of the centrifugal weights upon the curved lever e, and by the
action of this lever in turn upon the spring pin, and will thus be disengaged
from the lever O. As soon however as the speed of the axle becomes
sufficient to prevent the centrifugal weights from acting upon the levere the
ping will be forced inward by its spring, and its end will project across the
slot i in front of the draw bar lever O. Now if a brake be applied to the locomotive
or to any one car in the train ahead of the one having this brake upon it the draw
bar will be forced backward, and this will cause the lower end of the draw bar
lever to be thrown forward, and that will carry with it the end of the spring pin
in front of it, and that in its turn by means of the connecting link will draw the
friction shaft pulley forward until its pulley or drum and the drum upon the axle
are brought into contact, and the brake applied in a manner similar to that before
described. The heavy spring p will yield for backward motion of the draw bar in
excess of that required to apply the brake. When the train is again nearly at a
standstill the centrifugal weights will act upon the curved lever e to cause the
spring pin g to be withdrawn from across the slot i, and thus disengaged from the
draw bar lever O, thereby allowing the friction pulleys on the shaft I and axle to
become separated and the brake to be released. If when the train is started it
is pushed instead of being drawn, the draw bar will be forced backward, and the
lower end of the draw. bar lever O will consequently be thrown forward, so that
when the centrifugal arrangement ceases acting on the spring pin g the end of the
pin will be forced across the slot i behind the draw bar lever. Under these
circumstances any further forcing in of the draw bar will only cause the draw bar
lever to be forced against the forward end of the slot, while an outward pull on the
draw bar will cause the said lever to be thrown back against the spring pin g, but
inasmuch as the latter cannot move back of the longitudinal centre of the slot the
operation will have no effect upon the brake. The springs p, p', will yield also in
this case to allow for excessive motion of the draw bar. Upon bogies having no
safety beams the supports for the shafts, and such other portions of the mechanism
shown in the Drawings as bolted to the safety beams are fastened to the transom
instead. By making the loop like bearing piece g³ long enough to allow the pin
to travel the full length of the slot i, and by placing the support or fulcrum near
the centre of the pin instead of at the end, and by the use of two of the connecting
links j, one upon each side of the support, the brake may be made double acting,
that is, to cause a pushing in of the draw bar to apply the brake when the train
was started by drawing, or to cause a drawing out of the draw bar to apply the
brake when the train was started by pushing, in a manner similar to the brakes
described in the Letters Patent hereinbefore referred to. The spring locking pin g
can be actuated by means other than the curved lever e. One arrangement for the
purpose is shown in sectional front elevation in Figure 35, and in plan in

page_text: Figure 36. The same letters of reference indicate the same parts as in Figures 23,
to 34. The bracket N in this arrangement is a simple L shaped piece having its
vertical arm fastened to the transom D. The curved lever e is dispensed with, and
while the friction drum and centrifugal gravity mechanism are, as before, carried.
on the axle, the drum is a plain one made in two parts, clamped on the axle, and
provided with prolongations which carry the roller weights and their radial guide
studs or rods, which are exposed as shown and not housed within the drum, the
collars at the outer ends of the studs being enlarged to prevent any possibility of
the studs catching the brake chains. The sliding spring pin g in this case is
operated by the action of the roller weights upon a vibratory lover P' jointed to an
L shaped connecting rod or bar R, whose upright arm encircles the spring pin
between two collars fixed thereon. The lever is forked so as to straddle the axle,
and is pivoted at a to a U shaped supporting bracket S. One of the arms of the
forked lever is prolonged before the pivot as at PS, and to this prolongation Ps the
connecting bar R is jointed. The lever is provided with a cam T which normally
projects into the plane of revolution of the roller weights, so that when the axle
revolves slowly enough to permit the roller weights to drop toward the centre
before reaching the cam, the lever will, by the action of the weights on the cam,
be pushed back, with the result of pushing back, through the instrumentality of
bar R, the spring pin from across the slot in the bracket.
Figure 37 represents in sectional elevation an arrangement of the relief spring a',
by means of which the power of the brake may be varied to correspond with tho
load carried by the car. The spring box a for the shaft I and the bearing piece 1³
are like those similarly lettered in the previous Figures. Upon the top of the
spring rests the head a² of a rod a³, which extends up through the top of the
spring box, and is loosely jointed at a to a lever pivoted at a to the bearing
piece I², and at its other end hinged at a to a shaft or bar as attached to the
bolster or some other part of the car frame which has the motion of the car springs
between it and the bogie frame, to which the relief spring arrangement is fastened.
Under this arrangement, as the car body settles upon its springs under the load
placed upon it, proportionate pressure will, through the intermediary of the instru-
mentalities just described, be applied to the upper end of the relief spring, so that
a greater strain on the brake chain will be required to lift the friction wheel
shaft I and its box a when the car is heavily loaded than when it is light. The
motion given by the operation of the springs between the axle journal boxes and
the bogie may be employed also to operate the arrangement just described.
Having described the nature of the said Invention and the manner of performing
the same, I declare that. what I claim as the Invention to be protected by the
herein before in part recited Letters Patent is,—
1st. The combination with the axle and friction pulley thereon, and the friction
pulley brake shaft operated to bring its pulley into contact with the friction pulley
on the axle at the times and in the manner, substantially as hereinbefore described,
of the relief spring arranged and operating to permit said shaft to recede from the
axle when the strain upon the brakes exceeds the prescribed limit, substantially
as and for the purposes hereinbefore set forth with reference to Figures 1 to 22 of
the Drawings.
2nd. The combination with the lower or friction pulley shaft and the upper or
winding shaft, of the connecting chain attached to the lower shaft, substantially
as hereinbefore described with reference to Figures 1 to 5, whereby the said
chain in applying the brakes is wound up rapidly at first and more slowly
afterwards.
3rd. In combination with the upper or winding shaft and the equalising lever,
the connecting chain attached to said shaft, substantially as herein before described
with reference to Figures 1 to 5, .so that when the brakes are applied it shall be
wound up rapidly at first and more slowly afterwards.
4th. The combination with the two shafts R, J, and the brake mechanism
operated thereby, of the chains connecting said parts to one another, and the-brake

page_text: mechanism arranged, substantially as hereinbefore set forth, with reference to
Figures 1 to 5, so that in applying the brakes they shall wind up rapidly at first
and more slowly afterwards.
5th. The combination with the lower or friction pulley shaft, of the castings S¹, T,
lever n, stop pin k, and their adjuncts, said parts being arranged for joint operation,
substantially as herein before set forth with reference to Figures 1 to 22.
6th. The combination, substantially as herein before set forth with reference to
Figures 1 to 22, with castings S', T, lever n, stop pin k, and their adjuncts, of the
levers X and Y, the equalising rod and spring or springs controlling the latter and
the draw bar.
7th. The combination, substantially as herein before set forth with reference to
Figures 1 to 22 of the lower or friction pulley shaft, the casting S, the relief
spring and bearing, and link c, the castings S, T, lever n, and stop pin k, and
their adjuncts, the upper brake or winding shaft, and the levers X, Y.
8th. The combination, substantially as herein described, with the lower or
friction pulley shaft R of the upper or winding shaft J, said parts being connected
with one another and with the brakes in the manner substantially as hereinbefore
set forth with reference to Figures 1 to 5 of the Drawings.
9th. The combination with the, wheel weights and their supporting arms and
springs of the vibrating cam yoke, the weighted rock shaft t, link a, and stop
pink, substantially as hereinbefore set forth with reference to Figures 1 to 22 of
the Drawings.
10th. The combination with the equalising lever and hand brake rod attached
thereto of the automatic brake or winding shaft connected with said equalising
lever, and the throw off spring connected to the brake applying mechanism,
substantially as herein described with reference to Figures 1 to 22 so as to be put
under tension only when the automatic brake shaft is operated to apply the
brakes.
11th. The combination with the automatic brake applying mechanism and the
throw off spring of the hand brake rod connected with said mechanism at a point
intermediate between the brake shoes and point at which the throw off spring is
attached to said mechanism, substantially as and for the purposes hereinbefore set
forth with reference to Figures 1 to 22 of the Drawings.
12th. In an automatic brake of the kind described a spring so arranged that
tension upon it shall be applied or increased when the automatic brake is applied❤
and shall be released or lessened when the automatic brake is. released for the
purpose of assisting in the release of such brake, said spring to act upon the
automatic brake and not upon the hand. brake, substantially as specified with
reference to Figures 1 to 22 of the Drawings.
13th. The combination of the draw bar, the vertical draw bar lever, the slotted
bracket, the friction pulley shaft, the sliding spring cross or locking pin connected
with said shaft, the centrifugal weights, and mechanism intermediate between
said pin, and weights operated by the latter to withdraw said pin from operative
connection with said lever, at the times and in the manner substantially as herein-
before set forth with reference to Figures 23 to 37 of the Drawings.
14th. The centrifugal weight device and friction drum mounted on the same
axle, in combination with the friction pulley shaft movable to and from said axle,
the shaft operating mechanism connected with and actuated by the movement of
the draw bar, and means, substantially as described, acted on at stated times by
the centrifugal weights to destroy operative counection between said mechanism
and shaft, substantially as herein beforo set forth with reference to Figures 23 to 37
of the Drawings.
15th. The combination, substantially as hereinbefore set forth with reference to.
Figures 24, 25, 33, 34, of the draw bar, the draw bar lever, the connecting bar Z,
the slide bar m, and the springs P. P².
16th. The slide bar m, its U shaped bearing piece o, o', and springs p, p³, arranged
on the underside of the draw bar timbers, in combination with the draw bar, the

page_text: draw bar lever, and the connecting `bar 1, substantially as set forth with reference
to Figures 33 and 34.
17th. The combination with the vertical draw bar lever and longitudinally
slotted guide bracket N of the friction pulley shaft, the sliding spring cross pin, the
lever e, the wheel axle and centrifugal weights thereon, substantially as and for
the purposes hereinbefore set forth with reference to Figures 23 to 37.
18th. The hollow friction drum mounted on the wheel axle, and provided with
an annular side slot, as described in combination with the centrifugal weights
housed within said drum and the lever e, substantially as set forth with reference to
Figures 26 to 30.
19th. The sliding spring cross pin in combination with the friction pulley shaft
and the connecting hook link, said shaft and pin being mounted in bearings so as
to be movable to and from the wheel axle, substantially as set forth with reference
to Figures 23 to 32.
20th. The friction pulley shaft and relief spring in combination with mechanism
arranged and operating substantially as described to increase the pressure upon the
relief spring proportionately to the increase of load carried by the car, substantially
as set forth with reference to Figure 37.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Tenth day of February, A.D. 1882.