IMPROVEMENTS IN SELF-ACTING RAILWAY-BRAKES
Year: 1880

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 14th August 1880.
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 is intended to be applied to railway carriages and waggons
whether constructed on the American or English systems, the term carriage being
hereinafter used indifferently for a passenger carriage or goods waggon. The
brake is entirely self-acting and independent, and is especially valuable for goods
trains, as it requires no connection with the breaks of other carriages or with
other carriages themselves except the ordinary couplings always used.
The Invention may be stated generally to consist in the combination with the
longitudinally movable draw or coupling bar of a railroad carriage, of a brake
mechanism operated to apply the brakes by a movement of the said bar in a
direction contrary to that in which the carriage is moving, whether it be going
forward or backward. The one upon the front end of the carriage only acts in
this way, the one upon the other end acting in an opposite direction. The
Invention is more especially intended to procure a motion that shall automatically
apply brakes of various kinds at required times, this motion to be derived from
the drawing or pushing under certain circumstances of the buffer, or coupling, or
draw bar; for instance, when a train is running ahead, if steam be shut off and the
engine brake applied, the carriages will push forward against the engine and thus
cause the brakes upon the carriages to be applied. Or if a train is backing and
steam be shut off and the engine brake applied, the carriages will draw upon their
Гоміл 071

page_text: couplings and thereby cause the carriage brakes to be applied. In short, whether
the locomotive be drawing or backing any checking of its speed by the operation
of its own brake or other sudden action will cause the brakes to be immediately
applied to any carriages in the train that may be fitted with this improved brake
gear so long as the motion of the locomotive continues to be retarded and until the i
train is very nearly or quite at a stand still, but the loosening of the brake of the
engine and its increase of speed on the application of steam will immediately
release the carriage brakes.
I will first describe one arrangement of the brake as applied to a carriage
constructed on the American or bogie system, but which with slight modification
may be adapted to carriages with side buffers on the English system, it being only
necessary to provide a means whereby the inward motion of the buffer heads shall
be transferred to the draw bar. The usual central buffer and draw bar slides in a
fixed guide and is kept in a certain position by springs when no strain is exerted
upon it. To this bar is jointed a brake controlling lever, which in this case is a
compound lever, consisting of a small lever pivoted on a larger one. Noither lever
has a rigidly fixed position, the smaller one being free at one end to move between
two stops upon the larger lever (subject to the restraint of a fulcrum pin at that
end to be hereafter described). The larger lever is free to move at either end
(except that it is also subject to the control of the same fulcrum pin) and at the
centre so far as a pin in a slot in the guide frame of the buffer bar will allow it to
go, both levers being held in a nearly central position by the springs when no strain
is exerted upon the buffer.
The end of the larger lever opposite the fulcrum pin is connected by a lever
and rods to the brake levers, which are so pivoted that while any outward push
upon the lever has no effect upon the brake, a drawing towards the centre applies
the brake shoes to the wheels, and consequently whichever way the lever may
be moved from a central position the brake is applied by one or the other of the
levers.
The fulcrum pin above mentioned is connected to one arm of an elbow lever
whose other arm extends down to the wheel axle, and has at its lower end a
semicircular flange concentric with the axle and having a semicircular recess in its
side. Cylindrical weights slide freely upon radial rods fixed on the axle, and as
the axle revolves slowly the weights slide in and out, but when the axle attains a
high speed the woights are held out by contrifugal force. A collar on the axle, but
prevented from turning therewith beyond a certain distance by two stops, carries
a semi-circular flange, whose periphery is just under the inner ends of the
cylindrical weights when they are in their outermost positions, but is of a greater
radius than the other flange on the elbow lever. These two flanges and the weights
and stops are in such relative positions that the collar flauge after turning with
the axle until stopped (when it remains stationary until the revolution of the axle
is reversed) will be in such a position that as a weight comes up with the revolution
of the axle, it will first slide inwards until it rests upon the collar flange, upon
which it will slide until it drops off, when, if the train is going very slowly, it will
enter the recess in the other flange. Then as the axle continues to rotate and carry
round the weight the latter will be rolled against the latter flange, and acting as a
friction roller will push the lever away and thereby draw down the fulcrum pin.
Except the axle be revolving very slowly the weights will not drop quickly enough
to enter the recess, and they will consequently have no effect upon the fulcrum
pin.
The operation of the brake is as follows:-Supposing both levers of the
compound lever are in a central position and that the train is at a stand still;
now if the engine commence drawing the carriage the buffer bar will be drawn out
a certain distance, the small lever will be drawn forward upon the large lever, and
the fulcrum pin will come up behind it. If steam be shut off and the engine and
carriages continue to run [with their previously acquired momentum at about a
.uniform speed or uniformly diminishing speed no power is exerted upon the brake,

page_text: but if the engine brake be applied the carriages will press forward against the
engine and against one another and press back the buffer bar and thereby apply
the brake. This will continue while the engine break is applied, and until the
carriage axle revolves sufficiently slowly to allow one of the centrifugal weights to
drop into the recess, and by moving the elbow lever draw down the fulcrum pin
to release the brake from the pressure of the buffer rod.
In backing the action is similar, except that the position of the levers and pins is
reversed, and the brake is applied by the drawing out of the buffer bar by the
momentum of the carriages.
Thus whether pulling or backing, so long as the speed of the engine is not
suddenly checked, there will be no effect on the brake, but the moment the speed
of the engine is checked, the buffer and draw bar is moved in a direction opposite
to that in which the carriage is moving, and the leverage instantly changes from
one end of the compound lever to the other, and the brakes are applied. Discs
may be used instead of levers, and the motion procured by the levers may be made
to apply the brake in various ways by clutches, by friction, or by levers. A latch
may be made to hold the fulcrum pin down until the axle again attains speed
enough to prevent the weight dropping into the recess, when the weight will
unlock the latch and allow the fulcrum pin to rise.
I will now describe a modification in which different means are employed for
drawing the fulcrum pin, and also for applying the brake.
A piston working in a cylinder (or a bellows like diaphragm) has a valve which
allows the contained air to be expelled when the diaphragm or piston is pressed
upward, but prevents the air re-entering except through a small hole, so as to
retard the descent of the diaphragm or piston. To the diaphragm or piston is
jointed the free end of a lever, which rests upon a double cam fast on the wheel
axle. A pawl pivoted to this lever rests in the forked free end of a straight lever
to which the fulcrum pin is jointed, and which when the pawl is in its lowest
position is engaged by the pawl, so that when the latter is pressed up by the cam
the fulcrum pin is drawn down. Before the pawl reaches its highest point, it is
disengaged from the said lever, which is then free to fall. Now if the wheel axle
is revolving rapidly, air enough will not enter through the small hole to allow the
diaphragm or piston to drop eutirely down before the cam again pushes it up, and
consequently the pawl will not fall low enough to engage the lever, and the fulcrum
pin will remain undisturbed. The compound brake controlling lever is connected
with the buffer bar as before, and with the brakes by an endless chain, so
arranged and connected by another chain with an oscillating lever that any motion
of the brake controlling lever either way from its central position will apply the
brakes. Through a hole in the other end of the oscillating lever passes loosely
another endless chain, which passes to and once around a collar upon the wheel
axle. Each side of this chain is fastened to the brake lever, and springs tend to
keep the chain loose about the collar. When the chain is tightened about the
collar, it is wound up upon one side and unwound upon the other, thereby applying
the brake. As the chain winds with the axle, it will run round until one of
two stops upon it causes the chain to be somewhat loosened upon the collar and so
prevent its further winding.
Friction pieces may be placed between the chain and collar to prevent friction
upon the chain when the train is running and the brake not applied. Chains
connect the oscillating lever with a similar arrangement at the other end of the car
and the hand brake.
I will now describe other possible modifications, but the method of operation
remains the same.
The draw bar, its guide, and springs are similar in principle to those already in
use, although somewhat modified in form. Instead of a compound lever I use a
single brake controlling lever, and the fulcrum pin is forced up by a spring, and
serves as a fulcrum for the lever whenever it enters one or other of two holes
in the broader end of said lever. The lever is connected with the draw bar by

page_text: a pin extending up through a slot in the top of the draw bar guide. The longer
end of the lever is connected with the brake rod by a chain, so arranged that
any movement of the lever in either direction causes the brakes to be applied.
Centrifugal roller weights slide on radial arms on the wheel axle, and the fulcrum
pin is connected to one arm of an elbow lever, as in the arrangement first described.
To the other arm of the elbow lever is pivoted a peculiar shaped shifter piece
having two semicircular recesses in its face. This shifter piece is free to be
turned so as to bring either recess over the axle by the cylindrical weights
pushing against it, when they move in the direction in which it is to be shifted.
when the axle revolves slowly, each weight as it passes under the axle drops to
the outer end of the arm, and remains there until it is carried high enough to
cause it to slide in upon the arm, when it will bring up against and rest upon
a curved end or wing of the shifter piece, upon which it will slide until it comes to
the rocess which for the time being is over the axle. If the axle be revolving very
slowly the weight will drop into the recess; but at a higher speed it will be carried
beyond and not fall into the recess. When a ball or weight does fall into the
recess and is then carried forward, it will as it rolls out of the recess push the
elbow lever back, and thus draw down the fulcrum pin. In consequence of
the wing at the end of the shifter piece being longer than the centre, the weights
will still continue to slide upon the wing, even though the one rolling against the
centre shall have pushed the elbow lever back. The object is to draw the fulcrum
pin when the train is running very slowly, and thereby destroy the working
connection between the draw bar and the brake rods, in order that the mechanism
may have opportunity to adjust itself to work properly when the train again
attains a high speed. For instance, if the engine has just begun to draw the train
ahead, and the fulcrum pin being depressed, the brake controlling lever will be
drawn forward until the rear hole in it comes over the fulcrum pin, which will rise
into this hole as soon as the axle revolves fast enough to prevent the weights
falling into the recess in the shifter piece. Under these conditions a pushing back
of the draw bar by the speed of the engine being checked, will cause the brake
controlling lever to apply the brake. When the carriage being backed the action
will be similar, except that the motions will be reversed, and the fulcrum pin will
rise in the foremost hole in the brake controlling lever.
In order to adapt the herein described automatic brake to carriages with side
buffers on the English system, the draw bar is free to move back far enough to
carry the nut upon its rear end a little away from the spring, in order to get more
motion for operating the brake than would otherwise be possible, although this is
not actually necessary, as the brake may be operated by the motion obtained by
compressing the spring alone. About the draw bar is a fixed collar, and in advance
of this a strong forked piece slides freely upon the draw bar between the collar and
a shoulder upon the draw bar ahead of the fork. The arms of this fork extend
outward and forward, and terminate immediately behind the buffer heads, so that
when the buffers are pushed back, the fork will also be pressed back. The brake
controlling lever, whose action and purpose are the same as when it is applied to
American cars, is pinned loosely to the fork immediately below the draw bar.
The operation of this arrangement is as follows:-When the waggon is being
drawn forward the draw bar will be drawn out until the nut comes against and
somewhat compresses the spring. The collar will bring the fork forward until its
front ends rest against the buffer heads. Now as soon as speed enough is obtained
to allow the fulcrum piu to come up behind the end of the lever, and thereby
establish working connection between the lever and brake shoes, any inward
pressure upon the buffers will cause the brakes to be applied. If the carriage
instead of being drawn ahead had been backed, the buffers, and consequently the
fork, would have been pressed in, the fork so that it would have been against the
collar upon the draw bar, and the nut at the rear end of the bar would have been
away from the spring. The fork would also be back against the collar upon the
draw bar, and when sufficient speed is attained to allow the pin to rise, it will rise

page_text: in front instead of behind the end of the lever, so that any drawing out of the
traction rod will cause the brake to be applied.
Referring again to carriages constructed on the American system, when a
continuous draw bar is used, the brake controlling lever is not pinned directly to
the draw bar, but to a supplemental bar by means of a pin passing up through a
slot in the frame. The supplemental bar passes freely through hangers attached to
the draw bar with a spring between them. The brake controlling lever can be
connected with the brakes, and arranged to operate as previously described, or it
may be combined with mechanism, such as I will now describe.
The brake controlling lever is connected to the draw bar in the manner just
described, but in lieu of a movable fulcrum pin, I use one which is never withdrawn,
and I make use of a different arrangement for dissolving and restoring working
connection at proper times between the draw bar or lever and the brakes. Tho
elbow lever operated from the axle of the carriage by the weights and the shifter
piece, as herein before described, is connected in this instance not to the fulcrum
pin, but to a chain which is attached to the upright arm of an elbow lever pivoted
on the brake controlling lever, and having the end of its horizontal arm forked to
straddle an upright fork on the brake controlling lever. The brake chain is not
fastened to the brake controlling lever, but passes around a sheave on the carriage
frame, and has both its ends attached to the brake rod. One part of the chain has
a collar which passes between the arms of the upright fork, which are far enough
apart to permit the collar to pass between them without obstruction, but below this
wide part of the fork there is a slot which is sufficiently narrow to prevent the
passage through it of the collar, so that when the brake controlling lever is moved
in the proper direction, the upright fork bearing against the collar will draw the
brake chain and so apply the brake, the collar and fork thus taking the place of the
movable fulcrum pin. When the train is moving very slowly, the elbow levor
operated, as herein before described, will, through the intermediary of the chain and
the forked lever which extends under the brake chain, lift the brake chain out of
the slot into the wider part of the fork, which will permit the collar to pass in
either direction without hindrance. Working connection between the brakes and
brake controlling lever will thus be dissolved. When the carriage again starts,
whether going forward or backward, the brake controlling lever will be moved so as
to bring the upright fork to one side or the other, as the case may be, of the collar,
the brake chain still being upheld. As soon however as high speed is attained, the
elbow lever, no longer acted on by the centrifugal weights, will let the brake chain
down into the slot with the collar on the proper side of the upright fork.
I will now describe a modification designed to obtain a certain movement of the
brake controlling lever before the main or regular draw bar is forced in either
direction. Within the usual draw bar is another with its head extending out
beyond the head of the main draw bar. The hole for the ordinary coupling pin is
elongated in the regular draw bar, but is of the usual size in the auxiliary bar, in
order that when the carriage is being moved, the inner bar may be free to move a
certain distance before the coupling pin comes in contact with the end of the slot
in the main draw bar. The latter has secured to it upon the under side a plate, to
which is pivoted one end of the brake controlling lever, whose other end has the
usual chain connection with the brakes. Power is applied to the lever from the
inner draw bar by means of the draft pin which passes from the inner draw bar
into the lever through a slot in the main draw bar.
The brake controlling lever is combined with mechanism for dissolving and
restoring its working connection with the brakes in any of the ways hereinbefore
set forth.

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 14th
February 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 is intended to be applied to railway carriages and waggons,
whether constructed on the American or English systems, the term " 'carriage
being hereinafter used indifferently for a passenger carriage or goods waggon. The
brake is entirely self acting and independent, and is especially valuable for
goods trains, as it requires no connection with the brakes of other carriages, or
with other carriages themselves, except the ordinary couplings always used.
The Invention may be stated generally to consist in the combination with the
longitudinally movable draw or coupling bar of a railroad carriage of a brake
mechanism, operated to apply the brakes by a movement of the said bar in a
direction contrary to that in which the carriage is moving, whether it be going
forward or backward. The one upon the front end of the carriage only acts in this
way, the one upon the other end acting in an opposite direction.
The Invention is more especially intended to procure a motion that shall
automatically apply brakes of various kinds at required times, this motion to be
derived from the drawing or pushing under certain circumstances of the buffor or
the coupling or draw bar. For instance, when a train is running ahead, if steam
be shut off and the engine brake applied, the carriages will push forward against
the engine, and thus cause the brakes upon the carriages to be applied. Or if a
train is backing and steam be shut off and the engine brake applied the carriages
will draw upon their couplings, and thereby cause the carriage brakes to be applied.
In short, whether the locomotive be drawing or backing, any checking of its speed
by the operation of its own brake or other sudden action will cause the brakes to
be immediately applied to any carriagos in the train that may be fitted with this
improved brake gear so long as the motion of the locomotive continues to be
retarded, and until the train is very nearly or quite at a stand still, but the
loosening of the brake of the engine, and its increase of speed on the application of
steam, will immediately release the carriage brakes.
I will first describe one arrangement of the brake as applied to a carriago
constructed on the American or bogie system, but which with slight modification
may be adapted to carriages constructed on the English system with side buffers, it
being simply necessary to provide a means whereby the inward motion of the
buffer heads shall be transferred to the draw bar.
In the accompanying Drawings, Figure 1 is a longitudinal section of a portion of
the bogie truck frame of a carriage provided with one arrangement of the improved
brake; Figure 2 is a transverse section of part of the same; Figure 3 is a plan of
the same partly in section.
Figures 4, 5, 6, and 7 are views of certain parts separately illustrating the
operation of the mechanism. The same letters of reference indicate the same parts
in these seven Figures.
A are the wheels; B, the axle; C, the bogie frame; and D; the brake shoes, all
of the usual construction. The brake levers, rods, &c., are for convenience of
illustration somewhat different from those now used, but are not necessarily so, as
the improvements may be adapted to the brake system already upon the carriages
in various ways. E is the usual central buffer and draw bar, which passes through
a guide frame 63 attached to the frame of the carriage, and has upon it two

page_text: springs a, so adjusted as to hold the bar E in a certain position, except when power
is exerted upon it, when one or the other spring is compressed, and the bar drawn
out or pushed back, according to which way the strain upon it may be. The
inner end of the bar E is pin-jointed at 6 to a small lever F pivoted at one end c to
a larger lever G. Neither of these levers has a rigidly fixed position, the smaller
one being free at one end to move between two pins d upon the larger lever
(subject to the restraint of a fulcrum pin e to be hereafter described), the smaller
lever being held in a central position by the bar E when no strain is exerted upon
the latter. The larger lever G is free to move at either end (except that it is also
subject to the control of the fulcrum pin e) and at the centre so far as the pin b,
which rises in the slot 6 in the guide frame 62 will allow it to go, but is held in a
nearly central position by two springs a¹ and a rod a² when no strain is exerted
upon the bar E. Jointed at f to the end of the lever G is a rod f, which is also
jointed to the end of another lever f¹, fulcrumed at f*, and connected at its other
end to a rod f³, which is jointed at its ends to the brake levers ft. The brake
levers have each a fulcrum pin g working in a slot g¹, in such a way that while
any outward push upon the lever has no effect upon the brake, a drawing towards
the centre applies the brake shoes to the wheels, and consequently whichever way
the lever may be moved from a central position, the brake is applied by one or the
other of the levers. The fulcrum pine cones up through a plate h, fixed to or
forming part of the carriage or the bogie frame, and is pivoted at its lower end h' (see
Figure 2) to the horizontal arm of an L shaped lever H. This lever has its
fulcrum at its elbow, and its other arm extends down towards the wheel axlo B,
and has at its lower end a semi-circular flange H', whose upper surface is concentric
with the axis of the axle. This flange has a semi-circular recess i in its sido
(Figure 5). jare radial arms (two or more in number) fixed upon the axle, and
upon each of these arms is a cylindrical weight & fitted to slide freely between the
axle and pins k³, so that as the axle revolves slowly the weights will slide in and out,
but when the axle attains a high speed the weights will be kept out by centrifugal
force. I is a collar fitting on the axle with sufficient friction to revolve therewith,
and are two pins projecting from the collar, so as to strike a fixed hanger m and
prevent the collar revolving with the axle more than the distance between the two
pins. This collar has a semi-circular flange n radiating from it, whose periphery is
just under the weights k when they are in their outermost positions, but is of
greater radius than the flange H'. These two flanges and the weights and stop
pins are in such relative positions, that after the collar I has turned with the axle
until one of the pins strikes the hanger m (when the collar will have no more motion
until the revolution of the axle is reversed), the flange n will be in the position shown
in Figure 1, one of its ends being vertical and parallel with the recess i in the
flange H, but sufficiently to the back of it, so that as the weight k comes up with
the revolution of the axle, it will first slide inwards until it rests upon the periphery
of the flange n, upon which it will slide along until it comes to its end, when, if
the train is going very slowly, it will drop into the recess i on the other flange H¹.
Then as the axle continues to rotate, the weight will bo rolled against the
flange H, and acting as a friction roller will pass out of recess i and push the
lower end of the lever H away. By this movement the stress of the spring h³
which presses upward against the lever H will be overcome, and the fulcrum
pin e will be drawn down. This will happen however only when the axle is
revolving very slowly, because at higher speeds the weights will not drop quickly
enough off the flange n to enter the recess i, and they will consequently fall, if at
all, upon the outside of the flange H', and will have no effect upon the fulcrum
pin.
The operation is as follows:-Suppose both levers F, G, to be in a central position
and the train at a standstill. Now if the engine commence drawing the carriage
the bar E will be drawn out until the pin b comes to the forward end of the slot b¹,
the lever F will be drawn against the front pin d upon the lever G, and the
fulcrum pin e will come up behind it. Now if the engine continues drawing, the

page_text: two levers will be held forward, but as there is a considerable space behind the
fulcrum pin, the brake will not be acted on. If steam be shut off and the engine
and carriages continue to run with their previously acquired momentum at about a
uniform speed or uniformly diminishing speed, the levers will assume the position
shown in Figure 3, where the large lever is in a central position, and the short
lever in front of the fulcrum pin, but no power is exerted upon the brake. If
now the speed of the engine be retarded by its own brake the carriages will press
forward against the engine and against one another and press back the buffer bar,
and, as in Figure 3, the wide ends of the levers were already back as far as the
fulcrum pin e would allow them to go, this pressure will force back the other end
of the lever G, as shown in Figure 4, and apply the brake through the medium of
the brake rods and levers. This will continue while the engine brake is applied,
and until the axle B revolves slow enough to allow one of the weights k to drop
into the recess i, and by forcing the elbow lever H outwards draw down the
fulcrum pin e and release the brake. This will not occur until the train has almost
stopped, say, at the last one or two revolutions of the axle.
In backing the train the action is similar except that the position of the levers
and pins is reversed, as shown in Figure 6, and the brake is applied by the drawing
out of the bar E by the momentum of the carriages, as shown in Figure 7. It is
obvious that the action of this arrangement is similar if upon either end of the
carriage. Thus, whether hauling or backing, so long as the speed of the engine is
not suddenly checked, the pin b will bear against one or the other end of the slot b',
and there will be no effect on the lever G, which will, in effect, move upon the
pivot ƒ³ as a fulcrum without operating the brake rods. But the moment the speed
of the engine is checked the bar E is moved in a direction opposite to that in
which the carriage is moving and the leverage instantly changes, the pin e becoming
the fulcrum, the resistance being at f, and the power being applied at b. The
levers F and G are in effect one and the same so soon as they are once positioned,
the lever F being employed in order that it may be shifted from one side to the
other of the fulcrum pin e, according to the direction in which the carriage is
moving, the fulcrum pin e being on the rear side of the lever F relatively to the
movement of the carriage.
Various modifications of the different parts may be made. For instance, it may
be preferable not to have the collar I run directly upon the axle B but upon a
separate concentric bearing, and to have a very small friction upon the axle to
carry it to its proper position. Discs may be used instead of levers, and the motion
procured by the levers may be made to apply the brake in various ways, by
clutches, by friction, or by levers. A latch may be made to hold the fulcrum pin e
down after it has been once drawn down, until the axle again attains speed enough
to prevent the weight dropping into the recess, when the weight will unlock the
latch and allow the fulcrum pin to rise.
The lever should always be long enough so that lost motion between the carriage
frame and bogie truck will not materially affect the brake, and a chain may be
made to connect the fulcrum pin and its lever in order to allow for difference in
motion.
Figures 8, 9, and 10 show a modification in which different means are employed
for drawing the fulcrum pin and also for applying the brake; Figure 8 being a
plan, Figure 9 a longitudinal section, and Figure 10 a detail view. A piston n
working in a cylinder n¹, Figure 9 (or a bellows like diaphragm, Figure 10) has a
valve o which allows the escape of the contained air when the diaphragm or piston
is pressed upward, but is closed by a spring n¹ to prevent the air re-entering except
through a small hole during the descent of the diaphragin or piston which is
thereby retarded. A rod o³ connected to the diaphragm or piston is jointed to the
free end of a horizontal lever o¹ which is pivoted at the other end o³ to the bogie
frame. Either a lug p or a roller upon the lower side of the lever o¹ directly under
the rod o³ rests upon a double cam p¹ fast on the wheel axle B. The fulcrum pin e
is in this case jointed to a straight lever J fulcrumed at J', and pressed upon by a

page_text: spring to force the pin e upward. A pawl K pivoted to the free end of the
lever o¹ rests in and against the forked free end of the lever J, and has a notch 8 in
it which, when the pawl K is in its lowest position, will engage the end of tho
lever, as seen in Figure 9, so that when the pawl is pressed up by the cam p¹acting
on the lever o¹, this end of the lever J will be raised and the fulcrum pin e
consequently drawn down. Before the pawl reaches its highest point its upper end
will come into contact with a projection 8', and be forced away from the lever J
sufficiently to disengage the latter from the notch and allow the lever to fall. Now
if the wheel axle has attained sufficient speed, air enough will not enter through
the small hole to allow the diaphragm or piston to drop entirely down before the
cam p' again pushes it up, and, consequently, the notch's in the pawl will not full
low enough to engage the lever J, and the fulcrum pin will remain undisturbed. A
wide plate L carries two rollers t one on each side of and in line with the free end of
the brake controlling lever G. An endless chain u passes around these rollers, and one
part is attached at t¹ to the free end of the lever G. Directly behind the rear roller
when the lever G is in its central position is another chain u¹ attached to chain u, so
that any motion of the lever G in either direction will draw on the chain u¹. This
chain u¹ is fastened to one end of a lever M, fulcrumed at M², and having at tho
other end a hole through which passes loosely an endless chain v, which also
passes once around a collar w upon the wheel axle B. Each side of this chain v is
fastened to the brake lever f, and each side has a spring y attached to it and
pulling in such a direction as to tend to keep the chain loose about the collar w.
When the chain is tightened about the collar by the movement of lever M,
the friction causes the chain to be wound up upon one side and unwound upon
the other, the drawing side pulling upon the brake lever ƒ' and applying the
brake.
As the chain winds with the axle it runs through the hole in lever M until one
of two stops upon it arrives at and draws the lever M towards the axle, causing
the chain to be somewhat loosened upon the collar, and so preventing its further
winding. Friction pieces may be placed between the chain and collar w to
prevent friction upon the chain when the train is running and the brake not
applied. The chains run to a similar arrangement upon the bogie truck at the
other end of the carriage, and the chains 2¹ to the hand brake.
I will now describe other practical modifications:-Figure 11 is a plan,
Figure 12 a longitudinal section, and Figure 13 a sectional end elevation of so
much of n bogie truck as needed to illustrate this modification of the Invention ;
Figure 13 is a detail; Figures 14, 15, 16, 17, are plans of the brake lever operating
mechanism in various positions.
A are the wheels; B, the axlo; C, a portion of the truck frame; D, the brake
beam; E, the brake shoes; F, the brake lever; and G, rods; H is the draw bar,
and I, J, its guide and springs. Bolted to the draw bar guide I is a plate a,
through a hole in which passes a vertical pin b. This pin serves as a fulcrum for
the lever K whenever it passes up into one or the other of the holes c in the
bronder end of the lever. Power is applied to the lever by means of the pivoting
pin & which connects it with the end of the draw bar H and extends up through
a longitudinal slot d¹ in the top of the draw bar guide. To the longer end of the
lever is attached a chain L which runs from one side direct to the brake rod G,
and from the other around a sheave e, and then back to the brake rod, so that any
movement of the lever in either direction causes the brakes to be applied. Upon
the axle B is a collar f, from which radiate four arms g with cylindrical weights g¹
sliding on them as the axle revolves, if said axle be not revolving at so high a
speed as to cause the centrifugal force to overcome the force of gravitation. A
lever M. pivoted to a support secured to the frame O has the end of one arm pinned
to the pin b, so that any downward movement of this end of the lever draws the
pin down, while upon the other hand the spring 6' forces this end of the lever
upward when the other end of the lever is disengaged. Pivoted at h to the other
arm of this lever is a peculiar shaped piece N which is free to turn upon the stud

page_text: or pin h as far as the pin i in the slot i will allow it to go, that being from the
position in which it is shown in Figures 11 and 12 to one in which the semicircular
recess in the side of piece N will occupy the position there occupied by the
recess. This shifting is done by the weights g' pushing against the piece N when
they move in the direction in which it is to be shifted. This piece N has curved
wings which are a little longer than the centre (see Figure 11), and also a little
higher (see detail Figure 13ª), except that there is a small piece at the centre
which is placed back a little way from the front, and is only employed to assist
in the changing of position. The action of the weights is similar to that before
described, that is to say, when the axle revolves slowly, each weight as it comes up
slides inwards against one of the wings of the piece N, upon which it slides until
it comes to the recess k. If the axle be revolving very slowly the weight will
drop into the recess. If, however, the axle has any considerable speed the weight
will not drop into the recess, but in consequence of the wing being thicker or
higher than the centre it will be carried beyond the recess and fall upon the
centre 7, upon which it will slide until it falls off the point of N and passes around
under the axle again. When a weight does fall into the recess and is then
carried forward against the centre of the piece N it will as it rolls out of the recess
push the piece N back, which movement causes the lever M to draw down the
fulcrum pin b and thus release the lever K. In consequence of the wing being
longer than the centre of piece N the weights will still continue to slide upon the
wing, even though the one rolling against the centre shall have pushed the piece
back. The object is to draw the fulcrum pin when the train is running very
slowly, and thereby destroy the working connection between the draw bar and the
brake rods, in order that the mechanism may have opportunity to adjust itself to
work properly under the circumstances to which it may be subjected when the
train again attains a high speed. For instance, if the engine has just begun to
draw the train ahead, and the fulcrum pin b being depressed the draw bar will be
drawn out, thus drawing forward lever K until the rear hole c comes over the
fulcrum pin b, which will at once rise up into this hole as soon as the axle revolves
fast enough to prevent the weights g¹ from falling into the recess in the shifter
piece N, the pin remaining in the hole c and there forming a fulcrum for the lever,
as indicated in Figure 14, until the train has again almost stopped. In the mean
time while any drawing out of the draw bar or its being forced back to a centro
position by the spring J will not materially affect the brake chain L a pushing
back of the draw bar will cause the lever K to draw upon that part of the chain
passing around the sheave, and will thereby apply the brake, as in Figure 15.
When the carriage is being backed by the engine the action will be similar, except
that the motions will be reversed, inasmuch as the draw bar will be forced back
when the carriage begins to move, and the fulcrum pin will rise in the foremost
hole c in the lever K, as shown in Figure 16. When, under these conditions, the
brake is applied to the engine so as to check its speed, the draw bar will be drawn
out and the end of the lever K will pull directly upon the brake rod, as seen in
Figure 7. When the steam is shut off from the engine and the train allowed to
run of its own momentum the brakes will not be applied. More or less than four
of the cylindrical weights g¹ may be employed.
In Figure 18 I have illustrated the method of adapting the herein described
automatic brake to carriages constructed on the English system, the means here
described being capable of being readily adapted to all the different arrangements
of automatic brake herein described. The draw bar H is free to move back far
enough to carry the nut upon its rear end a little way from the spring in order to
get more motion for operating the brake than would otherwise be possible, although
this is not actually necessary, as the brake may be operated by the motion obtained
by compressing the spring alone. Upon the draw bar is a fixed collar x, and in
advance of this a strong forked piece Z slides freely on the draw bar H between
the collar and a shoulder upon the draw bar in front of the fork. The arms of
this fork Z extend outward and forward, and terminate immediately behind the

page_text: buffer heads Y, as shown, so that when the buffers are pushed back the fork Z will
also be pressed back. The brake controlling lever K and fulcrum pin bare in
action and purpose the same as before, the lever K being pinned loosely to the
fork Z immediately below the draw bar. The operation of this arrangement is as
follows:-
When the carriage is being drawn forward the draw bar will be drawn out
until the nut comes against and somewhat compresses the spring. The collar a
will bring the fork forward until its front ends rest against the buffer hends. Now
as soon as speed enough is attained to allow the fulcrum pin 6 to come up behind
the end of the lever K, and thereby establish working connection between the
lover K. and brake shoes, any inward pressure upon the buffers will cause the brakes
to be applied.
If the carriage instead of being drawn ahead had been backed, the buffers and
consequently the fork Z would have been pressed in so that the fork would have
been against the collar x, and the nut at the rear end of the bar would have been
away from the spring, and when sufficient speed is attained to allow the pin b to
risc, it will rise in front instead of behind the end of lever K, so that any drawing
out of the draw bar will cause the brakes to be applied.
Referring again to carriages constructed on the American system, I have shown
in Figure 19 a continuous draw bar H¹. In this arrangement the lever K is not
pinned directly to the draw bar but to a supplemental bar H³ by means of pin d
passing up through a slot d' in the frame. The bar H2 passes frecly through the
hangers I attached to the draw bar and carrying between them a spring Ji
the bar H and held between two washers on the latter as shown. The lever K
can be connected with the brakes and arranged to operate as previously described,
or it may be combined with mechanism such as shown in Figures 20, 21, and 22,
which I will now describe.
upon
Figure 20 is a plan, Figure 21 an end elevation, and Figure 22 a longitudinal
section of so much of the brake mechanism as needed to illustrate the Invention.
The draw bar H is of the usual construction, and with it I prefer to use, in lieu of
the ordinary buffer spring, a spring shown at J2 called the "Vose Equalizer
Spring," which consists of one spiral spring surrounding two smaller ones, the same
being so formed and arranged with respect to one another that the outer spring will
be somewhat compressed before the inner ones receive pressure. I prefer to have
the outer spring comparatively light in order that the draw bar may move a certain
distance in either direction before the heavier and shorter inner springs begin to
be compressed. The same result can be obtained by using heavy and light springs
in various other ways. The lever K is connected to the draw bar in the manner
illustrated in Figure 19, but in lieu of a movable fulcrum pin as hereinbefore
described, I use a permanent fulcrum pin b which is never withdrawn, and I make
use of a different arrangement for dissolving and restoring working connection
at proper times between the draw bar or lever and the brakes. The elbow lever M
operated from the axle of the carriage by the weights g, g¹, and the shifter piece N
as hereinbefore described, is connected in this instance, not to the fulcrum pin but
to a chain m which passes up over a guide pulley on the lever K and is attached
to the upright arm of an elbow lover O pivoted at n on lever K, and having the
end of its horizontal arm forked, as shown in Figure 20, to straddle a fork P
swivelled on a vertical axis on the lever K. The brake chain L is not fastened
to the lever K, but passes from the brake rod G to and around the pulley e on the
carriage frame and thence back to the brake rod. One part of the chain passes
between the arms of the fork P and is provided at that point with a collar or
enlargement p. The arms of the fork P are far enough apart to permit the
collar to pass between them without obstruction, but below this wide part of
the fork there is a slot r through which the chain passes, and which is sufficiently
narrow to prevent the passage through it of the collar, so that when the lever K is
moved in the proper direction, the fork P bearing against the collar p will draw
the brake chain and so apply the brake, the collar and fork thus taking the place

page_text: .
of the movable fulcrum pin. When the train is moving very slowly, the lever M
operated as herein before described will, through the intermediary of chain m, draw
back the vertical arm of elbow lever O; the horizontal arın of said lever which
straddles the fork P and extends under the brake chain will thus be caused to rise
and lift the brake chain out of the slot r into the wider part of the fork, which will
permit the collar p to pass in either direction without hindrance. Working
connection between the brakes and lever K will thus be dissolved and the lever
will be free to move without operating the brakes. When the carriage again
starts, whether going forward or backward, the lever K will be moved so as to
bring the fork P to one side or the other, as the case may be, of the collar p, the
brake chain still being upheld by the elbow lever O. As soon however as high
speed is attained, the lever M, no longer acted on by the centrifugal weights, will
permit the elbow lever O to drop, thus letting the brake chain down into the slot r
with the collar p on the proper side of the fork P.
In Figures 23 and 24 is illustrated a modified construction of the draw bar,
designed to obtain a certain movement of the lever K before the main or regular
draw bar is forced in either direction. Within the usual draw bar H is another
and somewhat similar one H3, with its head extending out beyond the head of the
main draw bar. The hole for the ordinary coupling pin s is elongated in the regular
draw bar H, as shown at t, but is of the usual size in the auxiliary bar H³, in order
that when the carriage is being moved the inner bar may be free to move a certain
distance before the coupling pin s comes in contact with the end of slot t in the
main draw bar. The latter has secured to it upon the underside a plate, to which
is pivoted at 6 one end of the lover K, whose other end has the usual chain
connection with the brakes. Power is applied to the lever from the inner draw bar
by means of the draft pin d, which passes from the inner draw bar into the lever
through the slot d in the main draw bar. The lever K is combined with
mechanism for dissolving and restoring its working connection with the brakes in
any of the ways hereinbefore set forth.
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
hereinbefore in part recited Letters Patent is,-
1st. The combination, substantially as hereinbefore set forth, with the brake
shoes and the longitudinally moving draw-bar of mechanism, such as is herein
described, on the one hand connected with and deriving movement from the draw-
bar, and on the other hand connected with and arranged to operate the brake shoes
when the carriage is running in either direction, whether being pushed or drawn,
and mechanism, such as is herein described, arranged and operating when the carriage
moves slowly to dissolve working connection between the draw-bar and the brake-
shoes, and when the carriage moves at a higher rate of speed to permit working
connection between said parts to be automatically re-established, said connection
being automatically varied to accord with the direction of movement of the carriage,
so that in whichever direction the carriage moves, and whether being pushed or
drawn, the brakes shall be operated by a force or pressure upon the draw-bar in
a direction contrary to that which it received while the carriage was being
propelled.
2nd. The combination of the draw-bar, the brake controlling lever, the movable
fulcrum pin, the brakes and connections between the said brakes and the brake
controlling lever, the said parts or their respective equivalents being combined, and
operating in the manner and for the purpose substantially as herein before set forth
and illustrated in various modifications shown in the annexed Drawings.
3rd. The use in combination of the longitudinally movable draw-bar, the fulcrum
pin, the brake controlling lever movable in regard to the fulcrum pin (and connected
to the carriage frame and to the draw-bar substantially as described) and springs,
whereby said lever is held in a central or nearly central position when not acted
on by the draw-bar, substantially as herein before set forth.
4th. The use in combination of the longitudinally movable draw-bar, the brake

page_text: controlling lever connected to said bar and to the carriage frame, substantially as
described, the brakes and means for connecting them with said brake controlling
lever, in combination with the movable fulcrum pin and mechanism, substantially
as described, operated from the revolving axle of the carriage or truck to depress
5 said pin and disengage it from the brake controlling lever, at the time and in the
manner substantially as hereinbefore set forth.
5th. The respective combinations of parts forming the respective modifications
used for applying and removing brake power automatically, substantially as herein
described and illustrated respectively in the Drawings annexed in Figures 1 to 7,
and in Figures 8 to 10, and in Figures 11 to 17, and Figure 18, and in Figures 19
to 24.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Twelfth day of February, A.D. 1881.
A. M. CLARK. (L.S.)