IMPROVEMENTS IN APPARATUS FOR WORKING BRAKES ON RAILWAY TRAINS BY COMPRESSED AIR, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO BRAKES WORKED BY OTHER MEANS
Year: 1872

page_text: LETTERS PATENT to George Westinghouse, junior, of Pittsburg,
Pennsylvania, in the United States of America, but at present of
No. 20, Southampton Buildings, Chancery Lane, in the County
of Middlesex, for the Invention of “IMPROVEMENTS IN APPARATUS FOR
WORKING BRAKES ON RAILWAY TRAINS BY COMPRESSED AIR, PARTS OF WHICH
IMPROVEMENTS ARE ALSO APPLICABLE TO BRAKES WORKED BY OTHER MEANS."
Sealed the 18th June 1872, and dated the 24th April 1872.
PROVISIONAL SPECIFICATION left by the said George Westinghouse
at the Office of the Commissioners of Patents, with his Petition,
on the 24th April 1872.
I, GEORGE WESTINGHOUSE, junior, of Pittsburg, Pennsylvania, in the
5 United States of America, but at present of No. 20, Southampton
Buildings, Chancery Lane, in the County of Middlesex, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN APPARATUS
FOR WORKING BRAKES ON RAILWAY TRAINS BY COMPRESSED AIR, PARTS OF WHICH
A

page_text: IMPROVEMENTS ARE ALSO APPLICABLE TO BRAKES WORKED BY OTHER MEANS," to
be as follows:-
My Invention relates to improvements in apparatus for working
brakes on railway trains, which formed the subjects of a Patent granted
to C. D. Abel (being a communication from me), dated 11th August |
1871, No. 2235, and of Patents granted to me bearing date respectively
the 15th September 1871, No. 2436, the 10th October 1871, No. 2684,
the 24th February 1872, No. 595, and of a Provisional Specification
filed by me on the 28th March 1872, No. 933. In the Specifications of
these Patents, and in the said Provisional Specification, I described
various arrangements of pipes, valves, and apparatus whereby compressed
air could be made to operate the brakes, and particularly arrangements
in which duplicate air pipes were connected throughout a train, and
each brake carriage was provided with an auxiliary reservoir of com-
pressed air which could be made to operate the brakes at will when air
was admitted to or allowed to escape from either air pipe, or automatically
when a pipe gave way, or when a carriage became detached from the
train or ran off the line.
The object of one part of my present Invention is a simplification of
the arrangement and construction of valves for effecting these purposes,
and it consists chiefly in the introduction into the system of valves of a
peculiar compound valve arrangement which I will presently describe,
and which may be combined in various ways with valves such as have
been described in the Specifications above referred to, so as to enable the
results above mentioned to be attained in a more complete and simple
manner. In this new valve arrangement there are three valves united
by one stem, and fitted to work in a valve box having three chambers or
compartments. The first chamber communicates at one end with the
air pipe, at the other end with the second chamber, and at the side it
communicates with the auxiliary reservoir. It contains two of the
connected valves, one of which can close the opening to the air pipe, and
the other can close the opening at the opposite end of the chamber which
leads to the second chamber. The former of these valves is of larger
area than the latter, and there are holes through it near its periphery
and beyond its seating, which holes are covered by a disc behind the
valve pressed against its back by a spring. The second chamber com-
municates at one end, as above described, with the first chamber, at the
other end it communicates with the third chamber, and at its side it

page_text: communicates with the brake cylinder. Within this chamber there is
no valve, but the stem connecting the two valves above mentioned with
the third valve passes through it. The third chamber communicates at
one end, as stated above, with the second chamber, and at the other end
5 it is open to the atmosphere. It contains the third valve which can
close the passago from the second chamber.
The operation of these valves is as follows:-Assuming that the
auxiliary reservoir is not charged with compressed air, when compressed
air is admitted to the air pipe its pressure acting on the larger area of the
first valve causes it to open and so to admit air from the charged pipe
into the first chamber, the other end of which is closed by the second
valve being pressed against its seat by the opening of the first valve.
The air thus admitted into the first chamber, passes through the holes
near the periphery of the first valve, pressing away the disc which covers
5 them, and finds its way by the side opening of the chamber to the
auxiliary reservoir which it charges with compressed air. At the samė
time the third valve in the third chamber is opened, it being on the same
stem with the first valve, and thus air from the brake cylinder is free to
escape through the second chamber past the third valve into the third
O chamber, whence it escapes into the atmosphere, so that the brakes are
taken off by relieving the piston in the brake cylinder from pressure.
If now it be required to put on the brakes air is allowed to escape from
the air pipe either by turning a cock or opening a valve by hand, or
automatically when the air pipe gives way or when a carriage becomes
5 detached from the train or runs off the line, as described in the Specifi-
cations above referred to.
The auxiliary reservoir having been charged as above described with
compressed air, the pressure of the air in it communicated through the
side opening in the first chamber acts in that chamber on the disc which
closes the holes in the first valve, and forces that valve against its seat,
thereby closing communication with the air pipe. At the same time
this closing of the first valve causes the second valve to be opened and
the third valve to be closed, these valves being both on the same stem
with the first valve. Compressed air thus passes from the auxiliary
reservoir past the second valve into the second chamber, and thence by
the side opening of that chamber to the brake cylinder where it acts on
the piston so as to apply the brakes. At this time the end of the second
chamber is closed by the third valve so that the compressed air cannot
▲ 2

page_text: escape by the third chamber to the atmosphere. Thus by means of this
triple valve arrangement when the air pipes are charged with compressed
air the auxiliary reservoir is charged and the brakes are taken off, and
when air is discharged from the air pipes the brakes are put on by the
action of the air stored in the auxilliary reservoir. I have described the
action of this valve arrangement as if it communicated with only one air
pipe. By combining it however with double valves connected by a stem,
such as have been described in the Specifications above referred to, either
or both of the duplicate air pipes serve to work upon the auxiliary
reservoir and brake cylinder as above described. By referring to the
above-named Specifications it will be seen that these double valves are of
two kinds, one which opens the passage from the pipe of higher pressure
and closes the passage to the pipe of lower pressure, and the other which
closes the passage from the pipe of higher pressure and opens that to
the pipe of lower pressure.
In connecting the duplicate air pipe with the valve box above described
and with the brake cylinder such double valves are arranged as follows :—
The branch pipes from the two air pipes lead to double valves of both
kinds. From the side of the valve box of the first kind a pipe leads to
the triple valve box, and from the side of the valve box of the second
kind a pipe leads to one end of a valve box of the first kind, the other
end of which communicates with the second chamber in the triple valve
box, while its middle communicates with the brake cylinder. By this
arrangement of the two kinds of double valves in combination with the
triple valves either of the pipes that contains air of higher pressure
supplies the auxiliary reservoir, or both pipes if charged can supply it or
can supply the brake cylinder directly, or either of the pipes may be out
of use while the other remains effective.
Another part of my present Invention relates to the packing of pistons
used in pneumatic brake apparatus. For this purpose I employ a cup
leather of the kind ordinarily used for pistons of pumps, but as when
such a leather is used only occasionally in an air cylinder it is apt to dry
and shrink, I fit within it a metallic spring ring which presses its edge
outwards so as to keep it in contact with the interior surface of the
cylinder in which the piston works.
When the brake blocks become worn it is necessary to extend the
stroke of the levers and rods which work them so as to bring them to

page_text: bear on the periphery of the wheels.. When the brakes are worked by
pneumatic apparatus, this necessary extension of stroke is a source of
loss, because a part of the stroke of the piston which moves the brakes
is thereby occupied in merely taking up the slack of the levers, rods,
and brake blocks before the latter come to bear upon the wheels.
Part of my Invention relates to a mode of compensating for such
wear of the brakes, and I effect this in the following manner :-I provide
the rod which works the brakes with ratchet teeth, and I mount a pawl.
on a fixed part of the carriage frame, and another pawl on the lever
which moves the brake rod. Both these pawls are pressed by springs so
as to engage in the ratchet teeth of the brake rod. When the lever is
moved by the piston of the pneumatic brake apparatus, the pawl of the
lever being engaged in the ratchet teeth of the brake rod moves that
rod, and thereby causes the brakes to be applied. When the lever is
released and the brakes taken off by the action of a spring or counter-
weight in the ordinary way, the fixed pawl engaging in the ratchet teeth.
of the brake rod prevents that rod from moving back more than is.
sufficient to release the brake blocks from the wheels, while the pawl of
the lever in its back stroke can slip one or more of the ratchet teeth.
At the next forward stroke of the lever for putting on the brakes, its
pawl, engaging thus one or more teeth behind the point where it had
previously engaged, moves the brake rod so as to put on the brakes
without the loss of stroke consequent on the wear of the blocks.
Sometimes the brakes, instead of being acted on by a rod worked by a
lever, are moved by a rod worked by a pinion or by a chain wound on a
wheel. In such cases I fix on the spindle of the pinion or chain wheel
a ratchet wheel, and I mount a pawl on a fixed part of the carriage
frame and another pawl on the lever which works the pinion or wheel, the
action of these two pawls engaging with the teeth of the ratchet wheel
having a similar effect in taking up slack or compensating for the wear
of the brake blocks to that described with reference to the action of
the pawls on the ratchet teeth of the brake rod.
In suspending the brake blocks from the carriage framing certain
freedom must be allowed them to permit of the vertical oscillations of
the carriage on its springs while the brakes are bearing on the wheels,
and to allow for the wear of the blocks themselves. When the brakės

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Westinghouse in the Great Seal Patent
Office on the 25th July 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
WESTINGHOUSE, junior, of Pittsburg, Pennsylvania, in the United
States of America, but at present of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of April, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said George Westinghouse, junior, Her
special licence that I, the said George Westinghouse, junior, my executors,
administrators, and assigns, or such others as I, the said George Westing-
house, junior, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN APPARATUS FOR WORKING BRAKES ON RAILWAY TRAINS BY
COMPRESSED AIR, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO BRAKES
WORKED BY OTHER MEANS," upon the condition (amongst others) that I, the
said George Westinghouse, junior, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said George Westinghouse, junior, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to the
accompanying Drawings and to the figures and letters marked thereon,
that is to say:-
HEREAWAMants in annamatus for working brakes

page_text: in railway trains, which formed the subjects of a Patent granted to
Charles Denton Abel (being a communication from mc), dated the 11th
August 1870, No. 2235, and of Patents granted to me bearing date
respectively the 15th September 1871, No. 2436, the 10th October 1871,
No. 2684, the 24th February 1872, No. 595, and the 28th March 1872,
No. 933. In the Specifications of those Patents were described various
arrangements of pipes, valves, and apparatus whereby compressed air
could be made to operate brakes, and particularly arrangements in which
duplicate air pipes were connected throughout a train, and cach brake
carriage was provided with an auxilliary reservoir of compressed air, 1
which could be made to operate the brakes at will when air was admitted
to or allowed to escape from either air pipe, or automatically when a pipe
gave way, or when a carriage became detached from the train or ran
off the line.
The object of one part of my present Invention is a simplification of 1
the arrangement and construction of valves for effecting these purposes,
and it consists chiefly in the introduction into the system of valves of a
peculiar compound valve arrangement which I will presently describe,
and which may be combined in various ways with valves such as have
been described in the Specifications above referred to, so as to enable the 2
results above mentioned to be attained in a more complete and simple
manner, as will be understood on reference to the accompanying
Drawings, and to the letters and figures marked thereon.
Figure 1 represents a section of the compound valve arrangement, con-
sisting of three valves A, B, and O, united by one stem D, fitted to work 2
in a valve box having three chambers or compartments. The first or
upper chamber communicates by the end passage E with the pipe by
which compressed air is conveyed throughout the train, and by the side
passage F with the auxiliary reservoir of compressed air. In this
chamber there are two of the valves A and B, of which the upper valve A 3
has a greater area than the lower valve B, and has holes through it near
its periphery covered by a disc a, pressed against its back by a spring.
The second chamber communicates by a side passage G with the brake
cylinder, and the third chamber has an opening H to the atmosphere.
This third chamber contains the third valve O, which can close 3
upwards against a caoutchouc or leather seating c, when the valve A is
closed against its upper scat. The seating e is made with a little space
between its inner edge and the body of the valve box, so that when the

page_text: valve C bears against it the pressure of air above the seating shall press
it against the raised annular edge of the valve C, and thereby ensure the
tightness of its closure.
The operation of these valves is as follows:-Assuming that the auxiliary
reservoir is not charged with compressed air, when compressed air is
admitted into the air pipe it enters by the passage E, and its pressure
acting on the larger valve A opens it and closes the valve B. The
compressed air thus admitted flows through the holes in the valve A,
pressing away the disc that covers them, and by the passage F to the
auxiliary reservoir which it charges. At the same time the valve C being
on the same stem with A and B is opened, and air from the brake
cylinder issues by the passage G past the valve C, and through the
opening H to the atmosphere, so that the brakes are taken off by
relieving the piston in the brake cylinder from pressure. If now it be
required to put on the brakes air is allowed to escape from the air pipe
either by opening a cock or valve by hand, or automatically (in the manner
described in the Specifications referred to above) when the air pipe or
its connections give way, or when a carriage becomes detached or runs
off the line.
The auxiliary reservoir: having been charged with compressed air as
described above, the pressure communicated through the passage F
acting on the larger area of the valve A, and finding no escape by the
holes in its periphery, which are closed by the disc, raises that valve
against its-seat, and so closes communication with the air pipe by the
passage F. At the same time the valve B is opened and the valve O
closed, compressed air then flows from the auxiliary reservoir by the
passage F past the valve B, through the passage G to the brake cylinder,
where it acts on the piston so as to put on the brakes.
Thus by means of this triple valve arrangement when the air pipes
communicating with E are charged with compressed air, the auxiliary
reservoirs are charged and the brakes are taken off, and when air is
discharged from the air pipes the brakes are put on by the action of the
air stored in the auxiliary reservoir.
Fig. 2 represents a section of a construction of such a valve box in
which the lower valve O is replaced by a sliding ring K. In this case
the opening to the atmosphere is a side passage H, and the com-
munication to the brake cylinder is by the end passage G.

page_text: Fig. 3 represents a sectional plan on the line X, X. The ring K acts
as a circular slide which closes the opening H when the valve A is
seated, and leaves it open as shown in Fig. 2 when the valve B is seated.
The ring is divided at one side to allow it to spring so as to make an air-
tight fit in the cylindrical part of the valve box in which it fits, and a
steady pin k projecting into the slit of division prevents the ring from
turning round. The ring is connected to the valve stem by a pin ɩ,
passing through the sides of the ring and the stem. The action is in this
case the same as that described with reference to Fig. 1. Two such
valve arrangements as have been last described may be combined with a
double valve in the manner represented diagrammatically in Fig. 3ª. In
this arrangement the air pipe communicates with the valve box A by
the aperture P, the auxiliary reservoir communicates with the valve
box D by the aperture R, and the brake cylinder communicates with
the double valve box B by the aperture C. Also the two valve boxes 1
A and D communicate at their upper parts by a pipe E, and each has its
opening F and G to the atmosphere operated by the sliding ring. The
valves in A are loaded by a weight or spring so as to keep them down,
unless sufficient pressure of air be admitted by the pipe -P to overcome
the load and close the upper valve. When air is admitted gradually 2
by P, it passes the upper valve in A through the pipe E, and past the
upper valve in D to the reservoir by the pipe R; the lower valves in A
and D remaining closed, and the openings G and F remaining open. If
however air be admitted suddenly by P, the pressure closes the upper
valve in A and opens the lower, passing to the valve box B so as to close 2
communication with D, and to the brake cylinder, where it acts on the
piston so as to put on the brakes, no air being admitted to the reservoir:
If now air be discharged from P the brakes will be released, air escaping
from the brake cylinder by the route by which it entered. If however
the reservoir has been charged, then the discharge of air from the pipe P, 3
effected either by hand or automatically, in case of accident will cause
the valves in A to descend, and the pressure of air in the reservoir will
lift the valve in D, so that air can pass the lower valve and thence to
the brake cylinders, having closed communication with A by means of
the valves in B, and also having closed the escape aperture G by the 3
raising of the sliding ring. By again admitting air to the reservoir as
first described, the valves in D become seated downwards as well as
those in A, and the apertures F and G being thus opened the air escapes
from the cylinder and the brakes are released.

page_text: By combining the valve arrangement described with double valves
connected by a stem such as have been described in my former Specifi-
cations, either or both of the duplicate air pipes communicating
throughout the train can operate the auxiliary reservoir and brake
cylinder. On referring to the above-named Specifications it will be seen
that these double valves are of two kinds one (like B in Fig. 34) which
opens the passage from the pipe of higher pressure, and closes the
passage to the pipe of lower pressure, and the other which closes the
passage from the pipe of higher pressure and opens that to the pipe of
lower pressure. In connecting the duplicate air pipes with the reservoir
and brake cylinder, such double valves may be combined with the triple
valve arrangement in the manner shown in the diagram plan, Fig. 4.
In this diagram A and B represent the two air pipes communicating
throughout a train, R. the auxiliary reservoir, and C the brake cylinder;
Tis the triple valve arrangement above described, and D is one of the
double valve arrangements described in the Specifications above referred
to, whereby either of the pipes A or B that contains air at lower
pressure than the other is cut off. It will be seen that compressed air
conveyed along either or both of the pipes A and B will operate on the
auxiliary reservoir R and the brake cylinder O by means of the triple
valve arrangement T in the manner above described.
Sometimes it is desirable that either of the two communicating air
pipes may be employed to charge the reservoir, while the other pipe may
be used to operate the brakes. An arrangement of valves for this pur-
pose is shewn in the diagrammatic plan, Figure 5, where A and B
represent the two air pipes; O, the brake cylinder; R, the auxiliary
reservoir; T, the triple valve arrangement above described; D¹ and D
double valves such as that marked D in Figure 4; and E, one of the
other kind of double valve arrangements described in the former Specifi-
)cations referred to above, whereby the pipe containing air at higher
pressure is cut off from communication. From this arrangement it will
be seen that one of the pipes, such as A, may be employed to charge the
reservoir R, the compressed air from A passing by the one end of E and
past one of the valves in D', acting on the large valve in T, so as to
it and the farthest valve, and close the middle valve of T, and
passing the larger valve of T to the reservoir R. At the same time the
other pipe B may be charged with compressed air for putting on the
brakes, the air from that pipe passing the open valve e', and thence by.
the pipe G to the valve box D³ (where it will open the valve d¹ and
¡ open

page_text: close d), and thence to the brake cylinder C, where the pressure will act
on the piston so as to put on the brakes. If now the pipe B be relieved
of pressure, then the valve e being closed and e¹² being open the air in the
pipe G will have its pressure reduced. The valves d, d', will then be in
equilibrium, allowing the air from the brake cylinder to escape past
either or both of them, and either past the third valve in T to the
atmosphere, or by the pipe G and past the valve e' to the discharge
pipe B. Again assuming the reservoir R to have been charged with
compressed air, and the pipe B to be relieved of pressure, by relieving
the other pipe A of pressure the brakes will be put on for the valves
in E, and D' being in equilibrium the pressure is taken off the largo
valve in T, which is therefore closed, opening the second valve in T and
closing the third, so that compressed air will flow from R, past the
open valve in T, and opening the valve d, and closing d' into the brake
cylinder C.
Two pipes communicating throughout a train may be applied in con-
nection with valves in the manner represented on the diagram plan,
Figure 6. Here the one air pipe A is shewn with branches A¹ at each
end of the carriage for convenience of coupling, as has already been
described by me in the former Specifications referred to.
The other pipe x communicates with the triple valve arrangement T.
Assuming that is charged with compressed air it charges the auxiliary
reservoir R, keeping open the large valve in T and the third valve, and
closing the middle valve. Then compressed air admitted into the pipe A
will open the valve d and close d³, and pass into the brake cylinder C so 2
as to put on the brakes. And when air is discharged from A the
vàlves d and ď being in equilibrium the air from C will pass either d
into the pipe A or d³, past the third valve in T to the atmosphere, and .
thus the brakes will be taken off. Again, the pipe A being relieved of
pressure the brakes can be put on by discharging air from the pipe x, for 3
then the larger valve in T and the third valve will be closed, and the
middle valve will be opened, so that compressed air will flow from the
reservoir R past the valve & to tho. brake cylinder O. The air can be
discharged from ≈ either by a cock or valve opening directly to the
atmosphere, or by a cock Y in a branch connecting with A. In this 3
case the air admitted from x to A may serve for signalling by sounding
whistles or working gauges connected to the pipe A in the manner
described in former Specifications referred to.

page_text: Instead of one pipe A with branches A', as shewn in Figure 6, two pipes A
and B, with a third pipe X, may be employed, as shewn in the diagram
plan Figure 7. Here it will be seen that either of the pipes A or B can
be employed to work the brakes, while X when charged is employed to
charge the reservoir R, and when discharged to permit the air stored in
the reservoir to work the brakes. The contents of the pipe X may be
discharged into the atmosphere by a cock or valve, or into one of the
other pipes, as A, by means of a branch provided with a cock or valve,
the pipe A being thus rendered available for communicating signals.
The three pipes A, B, and X may be employed with a combination of
valves such as is shewn in the diagram plan, Figure 8, where F repre-
sents a double valve arrangement, such as was described in previous
Specifications referred to, having the upper valve ƒ of larger area than
the lower valve ft. D is a double valve arrangement like that described
above and marked with, the same letter, and G is a check valve of any
known form. It will be seen that the reservoir R can be charged from
the pipe X, the valve f being opened and closed by the pressure of
the air in the pipe X. At the same time the brakes can be put on by
charging either or both of the pipes A or with compressed air, and
taken off by discharging the air from both. Again, if the pipes A and B
be closed and air be discharged from X, the air stored in the reservoir R
closes the valve f, opens f', and passes G to the brake cylinder C, so as
to put on the brakes, and also to charge the pipes A and B for communi-
cating signals.
B
It will readily be understood that the several kinds of valve arrange-
ments described in this and in the former Specifications referred to
can be combined in many other ways so as to effect the working of
brakes and communication of signals according to various systems of
operation. The arrangements shewn in the diagrams, Figures 4, 5, 6, 7,
) and 8, described above are given as examples of how such combinations
of valves may be made, and although in these, for the sake of distinctness,
the several valves are shewn as if they were fitted in separate chambers,
it may be readily understood that they might be fitted into separate
compartments of one valve box so as to secure greater simplicity and
3 compactness of construction.

page_text: leather of the kind ordinarily used for pistons of pumps; but as when
such a leather is used only occasionally in an air cylinder it is apt to dry
and shrink, I fit within it a metallic spring ring which presses its edge
outwards so as to keep in contact with the interior surface of the
cylinder in which the piston works. Figure 9 represents a section of a
piston packed in this manner. P is the piston; L, the cup leather; and
R is a metallic spring ring inserted within the cup leather in a groove
formed in the edge of the piston.
When the brake blocks become worn it is necessary to extend the
strokes of the levers and rods which work them, so as to bring them to
bear on the periphery of the wheels. When the brakes are worked by
pneumatic apparatus this necessary extension of stroke is a source of
loss, because a part of the stroke of the piston which moves the brakes
is thereby occupied in merely taking up the slack of the levers, rods,
and brake blocks before the latter come to bear upon the wheels.
]
P
Part of my Invention relates to a mode of compensating for such wear
of the brakes, and this I effect in the manner shewn in Figure 10, which
represents a side view of a brake lever and rod arranged according to my
improvements. L is the lever which is fitted to work on the fulcrum
pin Z, being moved in the direction of the arrow for the purpose of putting a
on the brakes; R is the rod connected to the brake blocks or to the
levers which work them. The rod R is made with ratchet teeth, into
which engage a pawl mounted on the pin and another pawl Q
mounted on a pin q on the lever L; a rod S surrounded by a helical
spring is connected to the pawl Q, and passes freely through a slotted 2
hole in the tail of the pawl P. The spring being inserted between the
two pawls in a state of compression acts on both of them so as to cause
them to engage in the teeth of the ratchet rod R; T is a pin on the
lever L acting as a guide to the rod R. When the lever L is moved by
the piston of the brake cylinder or by other means in the direction of the 3
arrow, the pawl Q being engaged on a tooth of the rack moves the rod R
in the direction of the arrow, and thus causes the brakes to be applied,
the pawl P slipping along one or more teeth of the ratchet.
When owing to the wear of the brake blocks the rod R has to be
moved more than one tooth of the ratchet so as to apply the brakes with 3
sufficient force to the wheels, the pawl P having slipped more than one
tooth drops into the hollow of the next tooth, and when the lever L is

page_text: moved back so as to relieve the brakes, the pawl P'prevents the rod R
from moving back farther than the clearance between its point and the
face of the tooth which it has slipped. The lever. L, however, makes its
full stroke back with its pawl Q slipping the teeth of the ratchet, and
this pawl at the next forward stroke of the lovor acts on a fresh tooth,
so that a small stroke of the lever L serves to put on the brakes. Thus it
will be seen that the stroke of the lever for applying the brakes need
never exceed the amount necessary to move the ratchet rod one tooth,
however much the brake blocks may be worn, or the connections to
them slackened. The ratchet teeth may be in duplicate, one set being
fixed at the side of the other, so as to halve the spaces without diminish-
ing the strength of the teeth.
.
Sometimes the brakes instead of being acted on by a rod worked by a
lever are moved by a rod worked by a pinion or by a chain wound on a
wheel. In such cases I fix on the spindle of the pinion or chain wheel
a ratchet wheel, and I mount a pawl on a fixed part of the carriage
frame, and another pawl on the lever which works the pinion or wheel,
the action of these two pawls engaging with the teeth of the ratchet
wheel, having a similar effect in taking up slack or compensating for the
wear of the brake blocks to that described with reference to the action of
the pawls on the ratchet teeth of the brake rod. In such cases instead
of a ratchet wheel, a plain wheel with friction pawl like that used for
silent feed may be employed.
In suspending the brake blocks from the carriage framing certain
freedom must be allowed them to permit of the vertical oscillations of
the carriage on its springs while the brakes are bearing on the wheels,
and to allow for the wear of the blocks themselves. When the brakes
are taken off this freedom in the hanging of the blocks permits them to
cant, so that they bear on the wheels when it is not desired that they
should do so.
'
Another part of my Invention relates to a mode of hanging the brake
blocks so that when the brakes are on they shall have the necessary
freedom to accommodate themselves to the conditions of oscillation and
wear, and that when the brakes are taken off the brake blocks shall not
touch the periphery of the wheels. For this purpose I arrange the sus-
pension of the brake blocks in the manner shown in Figure 11, which
represents a side view of a brake block B with one of its suspending

page_text: rods S, and part of the rod R which works it to and from the periphery of
the wheel. The rod S is connected to the block B by a pin P working
freely in a slotted hole. From the sides of the rod S horns 8, 8¹, project,
and lugs b, b¹, projecting from the side of the block B rest on the horns
and act as fulcra, on one or other of which the block B can work so as
to accommodate itself to the periphery of the wheel, notwithstanding its
wear or the vertical oscillations of the carriage, the slotted hole P giving
it freedom.
When the block is drawn away from the wheel by the rod R it hangs
on the two fulcra b, b', so as to be clear from the wheel throughout its :
length.
Figure 12 represents a side view of a brake block B suspended in a
manner somewhat similar to that just described for a like purpose; but
in this case the horns of the suspending rods S are dispensed with by
placing the suspending pin P below the brake. rod R, and providing a 1
stud or stop T on the block B, which, when it is pulled away from the
wheel, bears against the rods S, and prevents the block being pulled over
into such an attitude that its lower part can touch the wheel.
The modes herein described of compensating for the wear of the brake
blocks, and for steadying them while providing for wear and oscillation 2
when the brakes are worked by compressed air, are applicable also when
the brakes are worked by other means, as may readily be understood, for
if the brake lever, instead of being moved by a piston, were moved by
some other power such as that of a screw worked by hand, the connection
above described of the lever to the brake rod by means of ratchet and 2
pawls, and the mode above described of suspending the brake blocks,
can be applied either conjointly or separately for the purposes above
mentioned.
Having thus described the nature of my Invention, and the manner
in which the same is to be performed, I claim,—
First. The use in railway brake and signal apparatus worked by fluid
under pressure of a valve arrangement, substantially as herein described
in reference to Figs. 1, 2, and 3.
3
Second. The several combinations of such valve arrangement with
other valves, communicating pipes, reservoirs, and brake cylinders, 8
substantially in the manner and for the purposes described in reference
to Figs. 4, 5, 6, and 7.