Improvements in Continuous Automatic Air Brakes for Railway Vehicles.
Year: 1897

page_text: Date of Application (in United Kingdom), 16th July, 1897
Complete Specification Left, 16th April, 1898-Accepted, 2nd July, 1898
Improvements in Continuous Automatic Air Brakes for Railway
Vehicles.
We, SOCIETE GENERALE DES FREINS LIPKOWSKI, of 37, Rue Taitbout, Paris,
in the Republic of France, do hereby declare the nature of this invention
to be as follows:-
This invention relates to improvements in continuous automatic compressed
air-brakes constructed on Lipkowski's or any other system.
The improvements more particularly apply to apparatus known as "air dis-
tributors, acting in combination with a double piston brake cylinder fitted with
one of Lipkowski's reducers," or with a single piston brake cylinder of
Wenger's type, and they also apply to the location of the brake-cylinder in the
"reducer" arrangement.
The object of these improvements is to ensure both increased rapidity in the
operation, or compression, of the brake mechanism, and simultaneousness in the
action of the brakes, and also to facilitate the release of such brakes and to avoid
the inconveniences which are apt to result from want of skill on the part of the
attendant. Most of these results are attained automatically, and solely through
the absolutely precise location and adjustment within strictly defined limits of
component parts or devices of the several brakes.
These improvements mainly consist:-
(1) In the employment of a special valve arranged upon the brake cylinder, and
enabling the air,-in the case of double piston cylinder with a reducer, to take
its time so as to pass readily from the brake-cylinder into the reservoir, whenever
the "steering or controlling mechanism is operated, whatever the rapidity of
the accelerated motion of the distributor may be.
(2) In the employment of a double slide valve enabling the air from the main
supply pipe to escape into the atmosphere under each vehicle, so as to bring about
a rapid depression within strictly precise limits; which, however, may be varied
at will before the apparatus is fitted together. This double slide valve is designed
to avoid any communication between the air from the main pipe and the exhaust,
when the brake is taken off, and enables the feeding of the apparatus to be so
retarded as to enable the pressure of the air supplied for the purpose of effecting
the release of the brake, to make its effect more rapidly felt at the rear end of

page_text: ་
the train, which renders the simultaneous operation of the several brakes still
more reliable.
This double slide valve further permits the air of the brake reservoir to be
placed into communication with the cylinder and reducer; and the release to be
effected progressively and rendered controllable at pleasure. Thus by this
arrangement, we obtain greater rapidity in releasing the brake, facility for con-
trolling and varying the same and more reliable simultaneousness in the operation
of the several brakes. These are the important results attained by the improved
arrangements here adapted. The double slide valve may be replaced by a single
slide valve combined with springs such as are used at present, and so timed as to
prevent the accelerating mechanism from being started at the time of the release,
as will be explained further on.
(3) In the employment of a diaphragm as a substitute for the piston previously
referred to, which imparts greater precision to the apparatus when in operation
by avoiding leakage or escapes of air.
(4) In the employment of a distributor which enables single piston brakes of
the Wenger type to participate in all the advantages of our improvements, viz:-
rapid and simultaneous operation, facility of release, and an automatic and strictly
limited, or precisely regulated, operation of all the parts; whereby single piston
apparatus are rendered capable of acting as rapidly as the arrangements compris-
ing two pistons and a reducer, and absolute synchronism is ensured in their opera-
tion relatively to double piston or any other types of apparatus of this class that
may be employed no matter how rapidly operating or how far perfected.
(5) In the general arrangement and operation of the devices employed.
It is generally known that in case of danger accelerated valves are employed
which permit the trains to be very rapidly brought to a standstill. This facility
of instantaneous stoppage is not, however, free from certain objections which may
arise in ordinary traffic; for it may be the cause of ill-timed stoppages, while the
excessive abruptness with which these valves act, causes inconvenience, or uneasi-
ness, to the passengers, in addition to which it has a damaging effect upon the
rolling stock.
And a more serious objection even, than this, arises from the fact
that by a simple indiscretion on the part of the engine driver the train may be
stopped at a dangerous point of the line and become the cause of a grave accident.
In the ordinary train service, also, brakes with accelerating valves, for "block-
ing" trains, are attended with the drawback of being slow in their operation and
exhibiting that want of uniformity, or simultaneousness, to which we have already
referred.
Now the arrangement herein described, whilst retaining all the advantages
derived from acceleration, obviates the inconveniences hitherto experienced
in working the brake "home" or in sudden blocking.
Normally, it is only necessary for the driver to exercise a certain depression,-
(within limits which are widely varied without any inconvenience)-in order to
start the brake mechanism of the first carriage; and as soon as this is done, all the
brake-shoes of the train, with the swiftness of lightning will apply themselves
to their respective wheels. The driver, at this junction, has absolute control over
his entire train and it rests with him either, by a slight depression, to merely slow
or to stop the train altogether, and at once.
The delay which has been observed in the operation of apparatus of the
old types was ascribable to this circumstance; that the whole of the air,
in escaping from the main-pipe, had to make its way through the solitary
valve or tap provided at the "driver's end" of the apparatus.
Now the volume of air exhausted is an important consideration, as its escape
occupies more time in one case than in another, owing to the losses of weight which
have to be overcome. Besides all those inconveniences have had to be contended
with, which resulted from the great bulk of the air being carried towards the
driver's tap, and which, at one time, caused the head carriages of the train to
be unnecessarily relieved from brake action, and at another, subjected the car-

page_text: riages in the rear of the train to excessive pressure. In the most approved types
of quickly-acting brakes hitherto known, about one third of the volume of air con-
tained in the main pipe has generally been discharged. With our present
arrangement, however, it is only necessary for the engine-driver to allow one
twentieth of that volume of air to escape through the tap or valve placed near
him, in order to bring the brakes right home all along the train: hence the
rapidity of the operation of this improved brake arrangement is greatly enhanced.
And as all the brakes operate automatically, the train can be got ready to undergo
their operation with perfect reliability. Again, simultaneousness in the opera-
tion of the several brakes, whilst these remain applied to the wheels, is rendered
a great deal more certain, for it is well known that the moment the proper
relation of pressure and discharge is established in the main pipe, the effect of
the slightest depression will be felt almost instantaneously throughout the whole
length of the said main pipe. It follows, that, the less the amount of air the
engine driver is obliged to draw off through the tap, the more implicitly can the
simultaneous action of all the brakes be depended on. In the present instance
simultaneousness may be said to be increased seven-fold, so that, whereas until
now a space of three seconds was allowed for, as a reasonable time to elapse
between the working of the brakes in the first and last carriages of a train,
respectively, this interval is by our arrangement reduced to one half of a second
only, which, is so far as the operation of the springs at the train couplings is
concerned, is an utterly insignificant interval of time.
The novel arrangements which we have adopted to attain these objects combine
all the advantages resulting from the increased power of Lipkowski's brakes, their
greater controlability, and their comparatively small expenditure of air. But in
addition to these advantages, they possess those resulting from greater speed of
operation, which does not in the least effect any of the distinguishing qualities
of the arrangement, from almost absolute simultaneousness of operation in the
first stage-comprising the process of bringing the brake shoes nearer to the wheels
and that of applying a slight initial pressure; and lastly, while the brakes are
being applied, no matter whether with great or moderate velocity, from very
greatly enhanced-simultaneousness in the operation of them all.
At present, engine-drivers according to the number of carriages to be controlled
by brakes, are under the necessity of allowing greater or less quantities of air to
escape through the taps placed within their reach; and they ascertain the amount
of air thus escaping by time and by the noise which the air makes in issuing; but
to be able to take this as a criterion requires a certain dexterity and a great deal
of practice.
Owing to our present arrangements, however, an engine driver need only apply
an initial pressure of say 200, 300 or 600 grammes (as the case may be) in
order to start the brake mechanism of the first carriage of the train, solely as an
effect of the automatic acceleration, and then to stop the train whenever he thinks
fit by a second depression. It is not therefore necessary for the driver to be
highly skilled or trained before he can effectively and reliably manipulate our
brake apparatus.
The brake apparatus comprises a brake cylinder and air reducer, having the
improved air distributor, a main conduit or train pipe of the brake, which is con-
nected by a branch with the air distributor, and a discharge valve for the brake
cylinder. The piston rod of the brake cylinder is connected to the brake mechan-
ism, comprising the shoes adapted to be applied to the brake wheels.
"
"
"
The brake cylinder is sub-divided into two compartments, called, respectively,
the reservoir and the "cylinder." Within the brake cylinder there is pro-
"reducer." This "reducing
vided a recess or hollow space which is termed a
chamber apertains to the piston rod, is subjected to the action of a repelling
spring, and is integral with the piston reciprocating within the cylinder proper,
while a fixed piston fits within the reducer which works over the said piston.

page_text: "
The reservoir, the cylinder proper, and the reducer, communicates respectively,
through channels or ports with the air distributor.
The foregoing description is given hiere merely to recall the main features of
the original brake, now improved, and in order more clearly to define the nature
of the improvements hereinafter described.
It will first of all be observed that a communication is established between the
cylinder proper and the reservoir by means of a passage and a valve attached to
a flexible diaphragm. The valve rests upon a seat opening into the reservoir.
The diaphragm is subjected to pressure from the cylinder on one side, while its
opposite side receives pressure from the reservoir through the narrow passage or
port, this last mentioned pressure, plus the pressure of the spring, being brought
to bear upon the cap.
66
The object of the valve, which we term a decanting" valve, will be herein-
after described. For the present we will deal with the air distributor, being the
main object of our improvements.
This distributor consists of a main body into which open the three channels,
hereinafter termed the first, second and third channels in front of which there
is a valve-face, having three ports, corresponding to the said channels and also
two orifices one of which, is situated opposite the channel or port, opening into
the external atmosphere, while the other, opens into a passage, provided under-
neath the valve-face at the point where the main pipe opens. On one side of the
valve face there is provided an orifice or port coinciding with the channel which
connects the reservoir and the, distributor case or chamber.
This face forms part of a cylindrical jacket, which is formed in the main body
of the distributor and surmounted by a cap or dome properly secured on the top
of it. The passage just mentioned simply consists of a helical groove formed in
the external surface of the said jacket and designed to place in communication
the tube connecting the distributor to the main pipe, with the upper part of the
piston of the distributor; the lower part of such piston communicating with the
said tube through a port.
Upon the surface opposite to the orifices in the cylindrical jacket there are
arranged two superposed slide valves, quite independent of each other, and
adapted to be operated successively by means of the rod forming part of the
piston. The first or outer slide valve or that one farthest from the centre of the
jacket has 4 ports corresponding to the orifices in the cylindrical jacket, and the
second or inner slide valve possesses a slot or notch, a port, and a connection in
the shape of a shell, supplemented by a conduit. The second slide valve is held
between the collars of the rod forming part of the piston rod, so as to participate
in the movements of the same, while the first slide valve is loose between such
shoulders which, however, act upon it, each in alternate succession with one
stroke lost in between relatively to the movement of the second slide valve. The
first slide valve is to this effect provided with arms upon which act the lateral
extensions of the said collars. A spring presses the first slide-valve against its
face, while another spring presses the second slide-valve against the first one.
The rod secured to the piston is guided by a sleeve forming part of the jacket,
and it has three abutments or stops subjected respectively to the action of three
springs of different and progressive resilience. Two of the stops are passed on to
rod loosely, while the third stop is firmly keyed thereto.
The piston is connected to a flexible diaphragm, properly secured to the body of
the distributor and arranged to divide the same into two parts absolutely inde-
pendent of each other.
At the lower part of the distributor there is an arrangement-called the
expanding" or tension-relieving device, designed to serve as a means for check-
ing or easing the brake-apparatus. This expanding device consists of two dia-
phragms, subjected to the action of a repelling spring and acting upon a spring
controlled valve, arranged to open outwards.
The diaphragms divide the expanding device into three spaces or chambers, 1, 2,

page_text: and 3, connected as follows:--the chamber 1 communicates with the main pipe
through a passage, and with the lower part of the piston through an orifice;
while the chamber 2 communicates with the reservoir through suitable channels,
and the chamber 3 is connected with the cylinder proper, through the medium of
other suitable channels.
An air distributor thus constructed operates in the following manner:-
Before proceeding further it should be observed that under the joint influence
of the above mentioned three springs in the dome the piston is raised and along
with it the said first and second slide valves and, this being so, the orifices in the
jacket and the orifices in the outer slide valve register respectively.
The main air supply, upon arriving through the branch of the train pipe, fills
the chamber of the expansion apparatus and the space below the piston, by pass-
ing through the conduit, and also the part the space above the said piston, by
passing through the helical channel, the orifice in the valve-face, the port of the
first slide-valve, and the slot in the second slide-valve. The air therefore passes
onto the reservoir through the channel of the cylinder proper, into the reducer;
and at the same time it passes into the compartment 2 of the expansion apparatus
and into the compartment 3 through the appropriate channel and passage.
All parts of the apparatus, therefore, are filled with air and the brake is ready
to be operated with a view to its application to the wheels.
The process of applying the brake is sub-divided into two periods, or stages
viz: the preparation stage and the final pressure stage.
The preparation stage comprises the initial depression, which may vary between
250 and 300 grammes of pressure in the main conduit. As soon as the equili-
brium of the piston is destroyed, such piston becomes displaced to the extent of
about 2 millimetres, and the second slide valve attached to it, is shifted accord-
ingly.
The spring is then compressed and the projection or washer on the rod applied
to the sleeve or socket of the jacket.
The resulting displacement of the second slide-valve causes the part of the first
slide-valve to be covered over by the said second valve, so as to cut off any com-
munication between the main conduit pipe and the portion above the piston, and
also, consequently, the communication with the cylinder, reducer and reservoir.
The effect of depression in the main pipe is only felt in the space below the
piston, and it causes such piston to descend for a further space of four milli-
metres, so that the second slide valve, by means of its shell, the pipe and the ports
restores communication between the main pipe and the exhaust; while through
the ports in the face and the first valve it also connects the said shell with the
open air exhaust, through the orifices just before the reducer and the cylinder
are cut off from the reservoir. Thus the main pipe and reducer are at this junc-
ture above started and they, only, for the time being, communicate with the
atmosphere.
It will be observed that the effect of the depression in the main pipe is also felt
in the compartment 1 of the expansion device viz: upon one face, or side, of the
diaphragm of such device, though no real action is produced thereon.
Directly the reducer is started, it is emptied and the piston derives the air from
the cylinder proper, through the decanting valve, into the reservoir, of which the
capacity increases. The position of the operating gearing is at this moment com-
pletely changed, and the brake shoes are applied to the carriage-wheels.
At this period the second stage of the brake-operating process commences, and
it does so in all cases automatically, as a result of the depression in the main
pipe owing to properly regulated acceleration. Under the influence of this depres-
sion, which the mechanism as here arranged, regulates of its own accord, the
piston descends for a further space, and carries along with it not only the second
slide-valve, but also the first slide-valve, since the shoulder of the rod T has just
before, come into contact with the arm of that slide-valve. In consequence of
this simultaneous engagement of the two slide-valves, the reducer is above retained

page_text: in communication with the atmosphere; the orifice of the main pipe being closed
by the slide valve.
The limited depression taking place in the main-pipe asserts itself above the
expansion device, whereof the equilibrium is destroyed; the springs yields to the
pressure, the valve is lifted from its seat, and more or less of the air contained in
the cylinder proper escapes through such valve; with the result that the pressure
in the said cylinder slightly goes down, and by so doing, enables the piston to
act upon the brake-operating gear, so as to bring about a slight application of
the brake if desired; for the accelerating effect may be so regulated as only to
work the operating mechanism itself, and to check its action even before the
equilibrium of the expansion device has been destroyed.
.
The apparatus is now ready for the effective application of the brakes and the
engine driver need only allow a very minute quantity of air to escape in order
to apply the brakes finally and "block" the train; the expansion meantime serving
to adjust and modify their pressure to suit requirements.
To take off the brakes it is only necessary to admit air once more into the main
pipe; as a consequence of which admission the expansion apparatus immediately
applies the valve to its seat, and the piston, is, at once, driven back for a distance
of four millimetres. This initial movement exerts its influence upon the second
slide-valve, which has been moved for a corresponding distance, so as to place
the reservoir in communication with the cylinder and reducer; the main conduit
pipe continuing cut-off. A further movement for a distance of either two or four
millimetres, performed by the said second slide-valve, opens up all the communi-
cations; and a third movement is transmitted to the two pistons, so that the
position of things is restored. It should be observed that these three movements
are performed in practice nearly at the same time, and especially is this so as
regards the first two movements which actually take place simultaneously.
From what has been here stated it will be seen that the depression is produced
in the main pipe, from one carriage to the next, with uncommon velocity and
yet never occasion inconvenient or ill-timed stoppages, such as might otherwise
occur where depression takes place with a view to eventually working the brakes
"home." For it will be understood that owing to the operation of the two slide
valves, and to the action of the decanting valve, the preparation stage is gone
through in the same manner in the case of each one of the brake cylinders, no
matter how long the train may be; and it does so practically at the same moment:
so that the effective application of the brakes is wholly under the driver's control
and subject to his will or judgment. Thus, then, all the advantages enumerated
in an early part of this specification are realised to the full.
When it is desired to obtain the same effects with continuous automatic brakes,
unprovided with an air reducer, the arrangement hereinafter described will be
found serviceable..
In this modification, the distributor comprises, in addition to the expansion
apparatus and distributor proper, formed of the piston and the two slide-valves,
an auxiliary reservoir communicating with the space above the said piston and
with the compartment 2.
The valve-face is here provided with only four ports, one port opening into the
helical passage leading to the main-pipe; another port being connected with
the open air escape pipe, a third port being conected through the channel with the
cylinder proper of the brake cylinder, and the fourth communicating with the
reservoir of such brake-cylinder. The first slide valve has three ports corres-
ponding to suitable orifices. The second slide-valve has one orifice or port, and
two shells, the latter of which opens side-ways into the chamber of space above
the piston.
The tube or jet communicates through the passage with the compartment 1 of
the expansion device. The brake-cylinder, through a passage communicates with
the compartment 3 of the said expansion device. The space above the piston,
being an extension of the auxiliary reservoir, communicates, through a passage

page_text: with the compartment 3 of the expansion apparatus. All the remaining parts of
the distributor are identical with the corresponding parts of the arrangement
first described, with this difference only-which has already been referred to
before that the cap or dome is here replaced by a chamber which we propose to
call the "auxiliary reservoir."
While at rest the parts of the distributor occupy the positions in which the
main pipe is in direct communication with the compartment 1 of the expansion
device and with the space below the piston, through the helical passages and
the ports also with the space above the said piston and, consequently, with the
cylinder and the reservoir; the piston being maintained in its raised position by
the combined action of the springs in the dome acting upon the rod.
The operation is the same as in the case of the Lipkowski's distributor. By an
initial depression the accelerating action is started, that is to say, the main pipe
is placed in communication with the atmosphere. When the depression, pro-
duced by the escape of air from the main pipe, is sufficient to move the operating
gear and, in fact, to bring about a slight initial application of the brakes, all the
driver has to do is to keep up the depression in the pipe, in order to bring the
brakes to bear upon the wheels with greater or less force, according as he thinks
fit. It should here be observed that the reservoir and cylinder become discon-
nected as soon as the brake-action has been started in the main pipe.
The object of the auxiliary reservoir is to act as a substitute for the reservoir
of the brake cylinder when the pressure therein becomes too low to admit of a
satisfactory operation of the expansion device.
It must be understood that we do not limit ourselves in any way to the special.
shapes or dimensions of parts hereinabove indicated; and that such parts may be
constructed of any suitable metal. Besides, we may replace the double slide-valve
arrangement by a single slide-valve combined with springs, so as to obtain a quick
release of the brakes and avoid the inconvenience of having to re-start the accelera-
tion process; as the slide-valve rapidly slides on the valve-face during the releasing
operation without giving the air time to pass through.
101
1
T 1
1002
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.
COMITLEIEDI MUITICATION.
Improvements in Continuous Automatic Air Brakes for Railway
Vehicles.
We, SOCIETE GENERALE DES FREINS LIPKOWSKI, of 37, Rue Taitbout, Paris,
in the Republic of France, do hereby declare the nature of this invention
and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement:-
This invention relates to improvements in continuous automatic compressed
air brakes constructed on Lipkowski's or any other system.
The improvements more particularly apply to apparatus known as "air dis-
tributors," acting in combination with a double piston brake cylinder fitted with
one of Lipkowski's "reducers," or with a single piston brake cylinder of
the Wenger type, and they also apply to the location of the brake-cylinder in the
"reducer" arrangement.
The object of these improvements is to ensure both increased rapidity in the

page_text: action of the brakes, and also to facilitate the release of such brakes and to avoid
operation, or compression, of the brake mechanism and simultaneousness in the
the inconveniences which are apt to result from want of skill on the part of the
attendant. Most of these results are attained automatically, and solely through
the absolutely precise location and adjustment within strictly defined limits of
the component parts or devices of the several brakes.
These improvements mainly consist: -
(1) In the employment of a special valve arranged upon the brake cylinder, and
enabling the air, in the case of double piston cylinder with a reducer, to take
its time so as to pass readily from the brake cylinder into the reservoir, whenever
the steering" or controlling mechanism is operated, whatever the rapidity of
the accelerated motion of the distributor may be.
(2) In the employment of a double slide valve enabling the air from the main
supply pipe to escape into the atmosphere under each vehicle, so as to bring about
a rapid depression within strictly precise limits; which, however, may be varied
at will before the apparatus is fitted together. This double slide valve is designed
to avoid any communication between the air from the main pipe and the exhaust,
when the brake is taken off, and enables the feeding of the apparatus to be so
retarded as to enable the pressure of the air supplied for the purpose of effecting
the release of the brake, to make its effect more rapidly felt at the rear end of
the train, which renders the simultaneous operation of the several brakes still
more reliable.
This double slide valve further permits the air of the brake reservoir to be
placed into communication with the cylinder and reducer; and the release to be
effected progressively and rendered controllable at pleasure. Thus by this
arrangement, we obtain greater rapidity in releasing the brake, facility for con-
trolling and varying the same and more reliable simultaneousness in the operation
of the several brakes. These are the important results attained by the improved
arrangements here adopted. The double slide valve may be replaced by a single
slide valve combined with springs such as are used at present, and so timed as to
prevent the accelerating mechanism from being started at the time of the release,
as will be hereinafter explained.
(3) In the employment of a diaphragm as a substitute for the piston previously
referred to, which imparts greater precision to the apparatus when in operation
by avoiding leakages or escapes of air.
(4) In the employment of a distributor which enables single piston brakes of
the Wenger type to participate in all the advantages of our improvements viz:-
rapid and simultaneous operation, facility of release and an automatic and strictly
limited or precisely regulated operation of all the parts; whereby single piston
apparatus are rendered capable of acting as rapidly as the arrangements compris-
ing two pistons and a reduced and absolute synchronism is ensured in their opera-
tion, relatively to double piston or any other types of apparatus of this class that
may be employed no matter how rapidly operating or how far perfected.
(5) In the special arrangement of the diaphragms employed in the air distributor
or the decanting valve for the purpose of bringing about perfect tightness and
avoiding injurious reactions, as well as tearing strains produced by air pressure.
(6) In the general arrangement and operation of the devices employed.
It is generally known that in case of danger accelerating valves are employed
which permit the trains to be very rapidly brought to a standstill. This facility
of instantaneous stoppage is not, however, free from certain objections, which may
arise in ordinary traffic; for it may be the cause of ill-timed stoppages, while the
excessive abruptness with which these valves act, causes inconvenience, or uneasi-
ness, to the passengers, in addition to which it has a damaging effect upon the
rolling stock. And a more serious objection even, than this, arises from the fact
that by a simple indiscretion on the part of the engine driver the train may be
stopped at a dangerous point of the line and become the cause of a grave accident.
In the ordinary train service, also, brakes with accelerating valves, for "block-

page_text: ing" trains, are attended with the drawback of being slow in their operation and
exhibiting that want of uniformity, or simultaneousness, to which we have already
referred
Now the arrangement herein described, whilst retaining all the advantages
derived from acceleration obviates the inconveniences hitherto experienced
in working the brake "home" or in sudden blocking. Normally, it is
only necessary for the driver to exercise a certain depression, (within
limits which may be widely varied without any inconvenience) in order to start the
brake mechanism of the first carriage; and as soon as this is done, all the
brake-shoes of the train, with the swiftness of lightning will apply themselves
to their respective wheels. The driver, at this juncture, has absolute control over
his entire train and it rests with him either, by a slight depression, to merely slow
down or to stop the train altogether, and at once.
The delay which has been observed in the operation of apparatus of the
old types was ascribable to this circumstance:-that the whole of the air
in escaping from the main pipe, had to make its way through the solitary
valve or tap provided at the "drivers end" of the apparatus. Now the
volume of air exhausted is an important consideration as its escape occupies
more time in one case than in another, owing to the loss of weight which
has to be overcome. Besides, all those inconveniences have had to be contended
with, which resulted from the great bulk of the air being carried towards the
driver's tap, and which, at one time, caused the head carriages of the train to
be unnecessarily relieved from brake action, and at another subjected the car-
riages in the rear of the train to excessive pressure. In the most approved types
of quickly-acting-brakes hitherto known, about one third of the volume of air con-
tained in the main pipe has generally been discharged. With our present
arrangement, however, it is only necessary for the engine driver to allow one
twentieth of that volume of air to escape through the tap or valve placed near
him, in order to bring the brakes right home all along the train; hence the
rapidity of the operation of this improved brake arrangement is greatly enhanced.
And as all the brakes operate automatically, the train can be got ready to undergo
their operation with perfect reliability. Again, simultaneousness in the opera-
tion of the several brakes, whilst these remain applied to the wheels, is rendered
a great deal more certain, for it is well known that the moment the proper
relation of pressure and discharge is established in the main pipe, the effect of
the slightest depression will be felt almost instantaneously throughout the whole
length of the said main pipe. It follows that, the less the amount of air the
engine driver is obliged to draw off through his tap, the more implicitly can the
simultaneous action of all the brakes be depended on. In the present instance
simultaneousness may be said to be increased sevenfold, so that, whereas until
now a space of three seconds was allowed for, as a reasonable time to elapse
between the working of the brakes in the first and last carriages of a train,
respectively, this interval is by our arrangement reduced to one half of a second
only, which, in so far as the operation of the springs at the train couplings is
concerned is an utterly insignificant interval of time.
The novel arrangements which we have adopted to attain these objects combine
all the advantages resulting from the increased power of Lipkowski's brakes, their
greater controllability, and their comparatively small expenditure of air. But in
addition to these advantages, they possess those resulting from greater-speed of
operation, which does not in the least affect any of the distinguishing qualities
of the arrangement; from almost absolute simultaneousness of operation in the
first stage, comprising the process of bringing the brake shoes nearer to the wheels
and that of applying a slight initial pressure; and lastly, while the brakes are
being applied, no matter whether with great or moderate velocity, from very
greatly enhanced-simultaneousness in the operation of them all.
At present, engine-drivers, according to the number of carriages to be controlled
by brakes, are under the necessity of allowing greater or less quantities of air to

page_text: escape through the taps placed within their reach; and they ascertain the amount
of air thus escaping by time, and by the noise which the air makes in issuing; but
to be able to take this as a criterion requires a certain dexterity and a great deal
of practice.
Owing to our present arrangements, however an engine driver need only apply
an initial pressure of, say, 200, 300 or 600 grammes (as the case may be) in order to
start the brake mechanism of the first carriage and also, consequently, the brakes
of the remaining carriages of the train, solely as an effect of the automatic accel-
eration; and then to stop the train whenever he thinks fit by a second depression.
It is not therefore necessary for the driver to be highly skilled or trained before
he can effectually and reliably manipulate our brake-apparatus.
The invention will be best understood by reference to the accompanying draw-
ings in which :-
-
Figure 1 is a plan on a reduced scale of a four-wheeled railway carriage pro-
vided with an automatic compressed air brake on Lipkowski's system, fitted with
our present improvements.
Figure 2 is a longitudinal section of the brake cylinder with an air reducer
formed in it, and an air distributor constructed in accordance with our improve-
ments.
Figure 3 is a vertical section of the distributor fitted to operate a double piston
cylinder and a reducer, the section being taken on line 3-3, Figure 5.
Figure 4 is a partial vertical section on line 4-4, Figure 5.
Figure 5 is a horizontal section on line 5-5, Figure 3.
Figure 6 is a vertical section on line 6-6, Figure 5.
Figure 7 is a partial horizontal section on line 7--7, Figure 3.
Figures 8, 8, 9, 9, 10 and 10 illustrate the operation of the main operative
parts of the air distributor.
Figure 11 is a vertical section of the air distributor fitted to operate with a
single piston brake cylinder of the Wenger type; the section being taken on
line 11-11 Figure 13.
Figure 12 is a partial vertical section on line 12-12, Figure 14.
Figure 13 is a horizontal section on line 13-13, Figure 11, and
Figure 14 is a partial horizontal section on line 14-14, Figure 11.
Like letters of reference indicate corresponding parts in all the figures of the
drawings.
Referring to Figure 1, A designates the brake cylinder and air reducer and
comprising the improved air distributor B, C represents the main conduit or train
pipe of the brake, which is connected by a branch a with the air distributor B. bis
the discharge valve of the cylinder A. c is the piston rod of the said cylinder A
connected to the brake mechanism comprising the shoes d and d¹ adapted to be
applied to the brake-wheels or drums e el respectively.
<<
The brake cylinder A is sub-divided into two compartments (as shewn in
Figure 2) called, respectively, the "reservoir" A¹ and the "cylinder" A². Within
the brake cylinder there is provided a recess or hollow space A³, which is termed
aL reducer." This "
reducing" chamber is connected to the piston rode which
is subjected to the action of a repelling spring f, and the said chamber is integral
with a pistong reciprocating within the cylinder proper marked A2, while a fixed
piston works within the reducer. The reservoir A', the cylinder proper A³,
and the reducer A³, communicate, respectively, through channels or ports a³, a³, a³
with the air distributor B.
The foregoing description is given here merely to recall the main features of
the original brake, now improved, and in order more clearly to define the nature
of the improvements hereinafter described.
It will first of all be observed that a communication is established between the
cylinder proper A3 and the reservoir A¹ by means of a passage 61 and a valve c¹
attached to a flexible diaphragm c². The valve c¹ rests upon a seat s opening into
the reservoir. The diaphragm c² is subjected to pressure from the cylinder on

page_text: one side, while its opposite side receives pressure from the reservoir through the
narrow passage or port 62; this last mentioned pressure, plus the pressure of
the spring s being brought to bear upon
the
03.
cap
..
The object of the valve c', which we term a decanting" valve will be herein-
after described. For the present we will deal with the air distributor, being the
main object of our improvements.
This distributor (Figures 3 to 7) consists of a main body into which open the
valve-face g having
three channels a¹ a² a³ in front of which there is a
ports o¹³ corresponding to the said channels a¹ a² and a³ and also two addi-
tional orifices or ports o and o5 one of which o, is situated opposite the channel or
port 6, opening into the external atmosphere, while the other o, opens into a
passage 15, provided underneath the valve-face g¹ at the point where the main pipe
opens. On one side of the valve face g¹ there is provided an orifice or port of coin-
ciding with the channel a¹ which connects the reservoir and the distributor case or
chamber.
This face g¹, forms part of a cylindrical jacket G which is formed in the main
body of the distributor and surmounted by a cap or dome G₁ properly secured on
the top of it. The passage 1³ just mentioned simply consists of a helical groove
formed in the external surface of the said jacket and designed to place in com-
munication the tube L, connecting the distributor to the main pipe, with the
upper part of the piston I of the distributor; the lower part of such piston, com-
municating with the said tube L through the port l¹.
Upon the valve face g¹, opposite to the orifices 02, 03, 01 and 05 there are
arranged two superposed slide valves t and t¹, quite independent of each other,
and adapted to be operated successively by means of the rod T connected with
the piston I. The slide valve t has 4 ports e, e¹, e², e³ corresponding to the
orifices 02, 03, 04, 05 respectively, and the slide valve t'. has a recess or passage i,
a port, and a connection in the shape of a shell, supplemented by a conduit &³.
The slide valve t¹ is held between the collars f¹ and f of the rod T, so as to parti-
cipate in the movements of the same, while the slide valve t is loose between such
shoulders which, however, act upon it, each in alternate succession, with one
strcke lost in between, relatively to the movement of the slide valve t¹.
slide-valve t is to this effect provided with arms g² g2 upon which act the lateral
extensions of the said collars f¹ f. A spring presses the slide-valve t against
the face g¹, while another spring presses the slide-valve t' against t.
The
The rod T, secured to the piston I, is guided, at g³, by a sleeve forming part
of the jacket G, and it has three abutments or stops h¹ h2 h³ subjected respect-
ively, to the action of the springs u³ ³ of different and progressive resilience.
The stops h¹³ are passed onto the rod T loosely, while the stop 2 is firmly keyed
thereto.
The piston I is. connected to a flexible diaphragm I¹ properly secured to the
body of the distributor and arranged to divide the same into two parts absolutely
independent of each other.
"
At the lower part of the distributor there is an arrangement called the "expand-
ing
or tension-relieving device, designed to serve as a means for checking or
easing the brake-apparatus. This expanding device consists of two dia-
phragms, subjected to the action of a repelling spring f and acting upon a
spring-controlled valve l, arranged to open inwards (Figure 3).
The diaphragms divide the expanding device into three spaces or cham-
Obers 1, 2 and 3, connected as follows: the chamber 1 communicates with the main
pipe through a passage l¹, and with the lower part of the piston through an
orifice 0 (Figure 3); while the chamber 2 communicates with the reservoir A¹
through the channels and a¹ (Figure 4); and the chamber 3 is connected with
the cylinder proper, marked A2 through the medium of the channels and a²
5. (Figure 3).
An air distributor thus constructed operates in the following manner: -
Before proceeding further it should be observed that under the joint influence

page_text: of the three springs u¹ u² u³ the piston I is raised and along with it the slide
valves and t¹, and, this being so, the orifices 03, 03, 04, 05 and the orifices e e¹ e² eð
register respectively; the orifice coincides with the orifice e¹ and the slot or
recess corresponds to the orifices e e as shown in Figures 3 and 4.
The main air supply C, upon arriving through the branch a of the train pipe
and jet L, fills the chamber 1 of the expansion apparatus and the space below the
piston I, by passing through the conduit ; and also the space above the said
piston, by passing through the helical channel 1, the orifice in the valve-face g¹
the port of the slide valve t and the slot or recess in the slide-valve t¹. The
air therefore passes onto the reservoir A' through the channel a¹ of the cylinder A³,
the ports i, e, 02 and the channel a²; and into the reducer A³, through the
ports, e, o and the channel a³; and at the same time it passes into the com-
partment 2 of the expansion apparatus through the channel a' and passage 1;
and into the compartment 3 through the channel a² and passage 13.
All parts of the apparatus, therefore, are fitted with air and the brake is ready
ir be operated.
The process of applying the brake is subdivided into two periods, or stages, viz.
the preparation stage and the final pressure stage.
The preparation stage comprises the initial depression, which may vary between
250 and 300 grammes of pressure in the main conduit. As soon as the equilibrium
of the piston I is destroyed, such piston becomes displaced to the extent of about
2 millimetres, and the slide valve t, attached to it, is shifted accordingly.
The spring u is then compressed and the projection h¹ applied to the sleeve
or socket g3 (Figure 8).
.
The resulting displacement of the slide-valve t¹ causes the port of the slide
valvet to be covered over by the said valve t¹ (see Figures 8 and 8^) so as to cut
off any communication between the main conduit pipe and the portion above the
piston I, and also, consequently, the communication with the cylinder, reducer
and reservoir.
The effect of depression in the main pipe is only felt in the space beneath the
piston I, and it causes such piston to descend for a further space of four milli-
metres, so that (as shown in Figures 9 and 9*) the slide valve t, by means of its
shell, the passage 23 and the ports o3 and 05, restores communication between
the main pipe and the exhaust; while through the ports o³ and e¹ it also connects
the said shell with the open-air exhaust 64,-through the orifices e² and o4,-just
before the reducer and the cylinder A² are cut off from the reservoir A¹. Thus
the main pipe and reducer are at this juncture alone started and they, only, for
the time being, communicate with the atmosphere.
it will be observed that the effect of the depression in the main pipe is also
felt in the compartment 1 of the expansion device, viz. upon one face, or side,
of the diaphragm of such device, though no real action is produced thereon.
Directly the reducer is started, it is emptied and the piston g drives the air from
the cylinder A2, through the decanting valve c¹ into the reservoir, of which the
capacity increases. The position of the operating gearing is at this moment com-
pletely changed and the brake-shoes are applied to the carriage wheels.
At this period the second stage of the brake-operating process commences, and
it does so in all cases automatically, as a result of the depression in the main pipe
owing to properly regulated acceleration. Under the influence of this depression,
which the mechanism, as here arranged, regulates of its own accord, the piston I
descends for a further space, and (Figures 10 and 10^) carries along with it not
only the slide valve t, but also the slide valve t, since the shoulder f of the
rod T has, just before, come into contact with the arm of that slide-valve. In
consequence of this simultaneous engagement of the two slide valves, the reducer
A is alone retained in communication with the atmosphere; the orifice o³ of the
main pipe being closed by the slide valve t.
The limited depression taking place in the main pipe asserts itself at 7 above
the expansion device, whereof the equilibrium is destroyed; the spring f yields to

page_text: the pressure; the valve is lifted from its seat; and more or less of the air, con-
tained in the cylinder A2, escapes through such valve; with the result that the
pressure in the said cylinder goes down slightly and, by so doing, enables the
piston to act upon the brake operating gear, so as to bring about a slight applica-
tion of the brake if desired; for the accelerating effect may be so regulated as
only to work the operating mechanism itself, and to check its action even before
the equilibrium of the expansion device has been destroyed.
The apparatus is now ready for the effective application of the brakes and the
engine driver need only allow a very minute quantity of air to escape in order
to apply the brakes finally and block" the train; the expansion meantime serv-
ing to adjust and modify their pressure to suit requirements.
"
To take off the brakes, it is only necessary to admit air once more into the main
pipe as a consequence of which admission the expansion apparatus immediately
applies the valve to its seat, and the piston I is, at once, driven back for a dis-
tance of four millimetres. This initial movement exerts its influence upon the
slide valve t', which has been moved for a corresponding distance, so as to place
the reservoir in communication with the cylinder and reducer; the main conduit
pipe continuing cut-off. A further movement for a distance of either two or
four millimetres, performed by the said slide valve opens up all the communi-
cations and a third movement is transmitted to the two slide valves and t,
so that things are restored to the position illustrated in Figure 3.
It should be observed that these three movements are performed in practice nearly
at the same time, and especially is this so as regards the first two movements
which actually take place simultaneously.
*
From what has here been stated it will be seen that the depression is produced
in the main pipe, from one carriage to the next, with uncommon velocity and yet
never occasions inconvenient or ill-timed stoppages, such as might otherwise occur
where depression takes place with a view to eventually working the brakes
home." For it will be understood that, owing to the operation of the two slide-
valves and t, and to the action of the decanting" valve c¹, the preparation
stage is gone through in the same manner in the case of each one of the brake-
cylinders, no matter how long the train may be and it does so practically at the
same moment; so that the effective application of the brakes is wholly under the
driver's control and subject to his will or judgment. Thus, then, all the advan-
tages enumerated in an early part of this specification are realised to the full.
When it is desired to obtain the same effects with continuous automatic brakes,
unprovided with an air-reducer, the arrangement shown in Figures 11 to 14 will
be found serviceable; it being simply a modified form of the arrangement des-
cribed in the above.
In this modification, the distributor comprises,--in addition to the expansion
apparatus and distributor proper, formed of the piston I and the two slide-
valves and an auxiliary reservoir Q communicating with the space above the
said piston I (Figure 11) and with the compartment 2.
.
The valve face g is here provided with only four ports; the port of opening
into the helical passage leading to the main pipe; the port of being connected
with the open-air escape pipe 64; the port of being connected through the chan-
nel with the cylinder proper of the brake-cylinder; and the port o communi-
cating with the reservoir of such brake-cylinder. The slide-valve has three
ports, e, e², et corresponding to the orifices 02 04 and of o7, respectively. The slide
valve has one orifice or port, 2, and two shells and, the latter of which opens
sideways into the chamber or space above the piston I.
The tube or jet L communicates through the passage with the compartment 1
of the expansion device. The brake cylinder, through the passage 13, communi-
cates with the compartment 3 of the said expansion device. The space above the
piston I being an extension of the auxiliary reservoir, communicates through
the passage with the compartment 3 of the expansion apparatus. All the
remaining parts of the distributor are identical with the corresponding parts of

page_text: the arrangement first described, with this difference only-which has already
been referred to before-that the cap or dome G¹ is here replaced by a chamber Q
which we purpose to call the "auxiliary reservoir."
While at rest the parts of the distributor occupy the positions in which they are
shown in Figures 11 and 12; that is to say, the main pipe is in direct communi-
cation with the compartment 1 of the expansion device and with the space below
the piston I, and, through the helical passage and the ports o³, e and i also with
the space above the said piston I and, consequently, with the cylinder and the
reservoir; the piston being maintained in its raised position by the combined
action of the springs u, u¹, and u² acting upon the rod T.
The operation is the same as in the case of the Lipkowski distributor. By an
initial depression the accelerating action is started, that is to say the main pipe
is placed in communication with the atmosphere through 1, 2, 2, 04 and 6.
When the depression, produced by the escape of air from the main pipe, is suffi-
cient to move the operating gear and, in fact, to bring about a slight initial appli-
cation of the brakes, all the driver has to do is to keep up the depression in the
pipe, in order to bring the brakes to bear upon the wheels with greater or less
force, according as he thinks fit. It should here be observed that the reservoir
and cylinder become disconnected as soon as the brake-action has been started in
the main pipe.
The object of the auxiliary reservoir is to act as a substitute for the reservoir
of the brake cylinder when the pressure therein becomes too low to admit of a
satisfactory operation of the expansion device.
It must be understood that we do not limit ourselves in anyway to the special
shapes or dimensions of parts hereinabove indicated; and that such parts may
be constructed of any suitable metal. Besides, we may replace the double slide-
valve arrangement by a single slide-valve combined with springs, so as to obtain
a quick release of the brakes and avoid the inconvenience of having to re-start
the acceleration process; as the slide-valve rapidly slides on the valve face dur-
ing the releasing operation without giving the air time to pass through.
Having now particularly described and ascertained the nature of our said in-
vention and in what manner the same is to be performed, we declare that what we
claim is-
1. In continuous automatic compressed air brakes, the principle of initial and
limited acceleration, with a view to the initial displacement of the working gear
and the commencement of a slight and strictly limited brake-action.
2. In continuous automatic compressed air brakes the provision of a double-
slide-valve arrangement, whereby, when the brake is to be applied, the accelera-
tion process may be started, while, when the brake is being released, such start-
ing of the acceleration cannot take place; which object can also be attained by
the combination of a single slide valve with suitably adapted springs.
3. In continuous automatic compressed air brakes, constructed on Lipkowski's
system, the provision of a valve, termed the decanting valve enabling the air to
pass from the cylinder into the reservoir the moment the working gear is set in
operation, substantially as specified with reference to Figure 2 of the drawings.
4. In air distributors for continuous automatic compressed air brakes, the com-
bination of the piston (I) subjected to the influence of the main pipe, with a
flexible membrane or diaphragm, for the purpose of ensuring greater precision in
the operation of the brakes, substantially as specified.
5. In continuous automatic compressed air brakes constructed in Lipkowskis
system, the provision of two slide valves (t and t¹) independent of each other and
connected, though with the loss of one stroke, in the case of one of the two valves
―with a piston (I); such slide valves operating in conjunction with the orifices
or ports (02 03 04 and 05) of a valve face (91), communicating respectively, with the
cylinder proper, the reducer, the atmosphere and the main pipe, as and for the
purpose specified with reference to Figures 3 to 10 of the drawings.

page_text: 6. The combination of slide-valves (such as t and t¹ (referred to in Claim 5,
with springs such as u¹ u² u³) and stops (hi h² h³) for the purpose of dividing the
movement of the slide valve t¹ into three fractions or strokes; the valve t parti-
cipating only in the 3rd of such strokes of the valve t, as and for the purpose
specified with reference to Figures 3 to 10 of the drawings.
7. In continuous automatic compressed air brakes, constructed on the Lip-
kowskis' system, the combination of the following parts: slide valves (such as t
and t and as referred to in the 5th and 6th Claims); a valve-face (such as g¹)
with ports communicating with the reservoir, cylinder reducer, the open air and
the main pipe, through a helical groove in the piston (I); an expansion chamber
subdivided into three compartments connected, respectively, with the main pipe,
reservoir and cylinder (all of which parts go to form the air distributor; the said -
expansion chamber being provided with an escape or exhaust valve discharging
into the open air; and a brake cylinder comprising the cylinder proper, a reser-
voir and a reducing chamber; all operating as and for the purposes stated with
reference to Figures 3 to 10 of the drawings.
8. In continuous automatic compressed air brakes of the Wenger type, the
combination, in the air distributors, of the following parts; slide valves (as shown
at tand and referred to in the 5th and 6th Claims); a valve-face (such as g¹)
the orifices or ports of which communicate, respectively, with the main pipe,
through a helical groove with the open air, and with the cylinder proper and
reservoir of the brake-cylinder; a piston I and an expansion chamber subdivided
into three compartments communicating, respectively, with the main pipe, the
space above the piston I, the expansion chamber comprising a valve discharging
into the open air; and the brake cylinder; all operating as and for the purposes
specified with reference to Figures 11 to 14 of the drawings.
9. In continuous automatic compressed air brakes of the Wenger type, the
combination of the slide-valves tt, valve face g¹, the piston I of the expansion
apparatus, and the brake cylinder, with an auxiliary reservoir Q placed in direct
communication with the top of the piston I; all arranged and operating as and
for the purposes specified with reference to Figures 11 to 14 of the drawings.
10. The continuous automatic compressed air brake on the Lipkowski system,
as hereinabove both generally and specifically described with reference of
Figures 1 to 10 of the drawings.
11. The continuous automatic compressed air brake of the Wenger type, as
hereinabove both generally and specifically described with reference to Figures 11
to 14 of the drawings.
..
100
1
ม
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.