AN IMPROVED VACUUM BRAKE APPARATUS FOR USE ON RAILWAY TRAINS
Year: 1883

page_text: LETTERS PATENT to Arthur Samuel Hamand, of N° 9, Bridge Street,
Westminster in the County of Middlesex, Member of the Institution of Civil
Engineers, for an Invention of AN IMPROVED VACUUM BRAKE APPARATUS
FOR USE ON RAILWAY TRAINS
COMPLETE SPECIFICATION filed by the said Arthur Samuel Hamand at the
Office of the Commissioners of Patents on the 8th November 1883.
ARTHUR SAMUEL HAMAND of N° 9 Bridge Street Westminster Middlesex Civil
Engineer [Member of the Institution of Civil Engineers,] AN IMPROVED VACUUM
BRAKE APPARATUS FOR USE ON RAILWAY TRAINS
My Invention has reference to that description of apparatus known as Continuous
Vacuum Brakes for use on Railway Trains
The chief objects effected by my invention are; Economy and simplicity in
construction and working, rapid efficiency, and complete and accurate control of
the power of the apparatus.
The principal features of my apparatus are; the application and release of the
brakes on the whole train including Engine and Tender by one operation, the
perpetual creation and maintenance of Vacuum in the brake cylinders, the almost
immediate release of the brakes when desired by means of a novel and peculiar
valve apparatus which also adds to the economy of working the brake, and the
automatic application of the brake to the whole train, including Engine and
Tender, in case of its failure or defectivo adjustment or the severance of the train
accidentally when running.
The apparatus consists of; a vacuum cylinder with piston and rod connected to
the brake gear, two train pipes one of which called the automatic pipe is connected
with both ends of the Cylinders but having in its connection with one end a
differential piston valve, the other pipe called the supplemental pipe is connected
to the same end of the cylinder at which the differential piston valve is fixed and
provided with a check valve between the cylinder and the supplemental pipe. The
train pipes are furnished at their ends with a length of lexible hose having
connections as hereinafter described
.
.

page_text: A compound ejector as hereinafter described is provided as well as an ordinary
Air Pump on the Engine to effect the exhaust. Each ordinary Coach is intended
to have one cylinder of suitable dimensions, the Engine Tender two Cylinders and
the Engine itself another small cylinder for controlling the cocks for the admission
of Steam to the Engine brake. The whole apparatus is controlled by one valve
placed in a position convenient for the Engine driver and a valve for applying the
brake is also provided in each Guards Van.
Having briefly explained the nature of my Invention I now proceed to describe
with reference to the accompanying drawings the manner in which the same is to
be performed
Figure 1, representing in Plan the underframe of a Railway Carriage, shews the
general arrangement of my improved apparatus for working the brakes of
Railway trains by means of vacuum or oxhaustion, and in using the word vacuum
throughout this Specification I must bo understood to mean vacuum more or less
partial
A. is the automatic pipe, B. the Supplemental pipe, C, the Brake Cylinder, D.
the differential piston valve, E. the. Exhaust check Valve, P. the piston rod to
which the brake gear is connected and R. a release cock for admitting air to the
reservoir end of the brake cylinder. a. is a branch pipe connecting the automatic.
pipe A with the brake cylinder C. a. is another branch connecting the brake
cylinder and automatic pipe with the differential piston valve D., b, is a pipe leading
from the supplemental pipe B. through the check valve E to the Cylinder C, r is a
wire or cord for opening the release cock without having to go under the carriage.
The two train pipes are crossed under tho Carriage in order that the pipes may
maintain the same relative positions at each end of the coach. on this account the
hose pipes will also cross diagonally between the Coaches.
Figure 2. represents in longitudinal Section my improved brake cylinder which
has its sides composed preferably of Steel or wrought iron sheet bent to the
cylindrical shape, having the two abutting edges planed true, with hoops, g. 9.
shrunk on to maintain its shape, the joint being made good with cement, or if
preferred the joint may be welded. The Covers c. c. slightly domed or buckled are
inade of a larger diameter than the Cylinder itself to form flanges, through which
pass several bolts, d. d. d. extending from Cover to Cover. Upon these bolts
being drawn up tight the two covers are pressed firmly against the ends of the
Cylinder. The edges of the Cylinder may either fit into a shallow groove in the
Covers prepared to receive them or the edges may butt on the Cover, some packing
medium being interposed to make a tight joint. One side of each Cylinder Cover
is prolonged and turned at right angles for the purpose of convenient attachment
to the underframe of the Coach. In one of the Covers is fitted a Stuffing box, 8,
through which passes the piston rod P, and which contains a cup leather or other
suitable packing, 2. The Piston P' is made of a buckled plate of such a shape as
to fit up closely into the hollow of the Cylinder Cover. The edge of the plate is
turned downwards and a ring of channel section, e, is shrunk on to the flange thus
formned. In this ring are placed three hoop springs, r, side by side, on which is
laid a band of metal sheet, i, Outside this band are placed rubber rings, p¹, circular
in section and laid side by side. This constitutes the packing of the Piston the
hoop springs maintaining the rubber rings always in close contact with the
Cylinder. A cup leather packing may be used if preferred. A washer of some
elastic medium, w, forms a cushion for the piston to butt against and adds security
against leakage. The piston rod is continued through the piston both ways, one
end passing through the Stuffing box, 8, and is connected with the brake levers,
the other end, being continued inside the cylinder some distance, carries on its
end a moveable piston guide. This guide consists of a boss, h, having a washer, W',
on each side of it, and being free to revolve on the piston rod, P, has not less than
three arms, m, equidistant from each other, each arm terminating in a small
roller, t, bearing upon the interior of the cylinder. These rollers are set at an angle
with the axis of the Cylinder the result being that as the piston moves the rollers

page_text: pass spirally round the interior of the Cylinder thus always travelling over new
surface for wenr. The piston rod being supported at both ends effectually
prevents any straining or undue wear that would take place if the piston rod
were supported at one end only, and obviates also the use of a very deep piston
with its consequent unnecessary weight and friction such as is used in some
existing forms of brake apparatus. A fixed guide for the piston rod may if
preferrod be used in the place of the foregoing moveable one. a, is the branch
pipe communicating between the automatic pipe, A, and the Stuffing box end of
the Cylinder, a, a pipe communicating between the automatic pipe A and the
reservoir end of the Cylinder having on it the differential piston valve D, and b.
is a pipe joining the Supplemental pipe, B., to the reservoir end of the brake
Cylinder having in it the check valve E. The brake gear is so arranged and
balanced that the normal position of the piston shall be at the Stuffing box end of
the Cylinder and the brakes are then all off. When the brakes are applied the
piston, P., travels up the Cylinder and the moveable piston guide in addition to
its forward motion turns spirally. The rubber packing rings, p¹, will also have a
tendency to roll and so present new surfaces to wear.
Figure 3 is a Section of part of the piston, shewing the packing rings et cetera
to an enlarged scale, the same letters indicating the same parts as in Figure 2.
Figure 4 Shews to an enlarged Scale a Section of part of the piston as adapted
for a Cup leather packing. Pl being the piston e. an angle iron ring shrunk on,
p the Cup leather packing and e. a moveable ring for securing the Cup leather
and bolted to the piston
Figuro 5 shews a vertical Section and Figure 6 a sectional plan at centre, of
the differential piston valve. D is a metal Casing or valve chamber divided near its
lower end by a rigid partition X, having a projecting boss through which slides
the hollow piston rod, y, attached at its upper end by flanges, y³, to a flexible
diaphragm, y', preferably of India rubber. The Valve box is thus divided into
three parts or chambers marked respectively 1. 2. and 3. The piston rod terminates
in a disc valve, y³, which abuts against a rubber seating, y',-X is a ferrule keeping
the rubber in position. The piston rod, y, is open at its upper end and has also
openings, y, just above the valve, y³, thus forming a passage always open, between
chambers and 3. 3º, is a Stop to prevent the piston moving upwards beyond a
certain distance. X is a hole which, when the valve, y³, is lifted from its seating,
comes opposite to a corresponding hole, X, in the boss of the partition X. X' is
nhole covered by an ordinary flap valve, opening inwards, of India rubber;
X³, hinged at one side and Stiffened at the back with a metal plate X, In place of
the rubber flap valve, X5, an India rubber ball valve may be used. The piston
Rod, Y, with the diaphragm y' and valve y³ may be termed as a whole the "piston
valvo.' The diaphragm, y', is made of a larger area than the valvo, y³, sny four
times the area, consequently a given vacuum acting on the diaphragm, y³, will
balance one of four times the intensity acting on the valve y',
The upper
chamber 1. is in Communication with the automatic pipe and the lower one 3
Communicates with the reservoir end of the brake cylinder.
The action of the differential piston valve is as follows
Supposing that a vacuum is being created in the train pipes the piston Valve
lifts and air is exhausted from the brake cylinder, part of it passes through the
supplemental pipe and part through the hollow piston rod. y, and thence through
the branch pipe, a¹, to the train pipe, A. The central chamber, 2, of the Valve
box is also exhausted in consequence of the piston valve having moved upwards,
and brought the hole, X², in the piston rod, y, opposite to the hole, X³, in the boss
through which it slides; or in the event of the piston not moving upwards
sufficiently far to do this, the same result would be obtained though more slowly
by the air being withdrawn around the piston rod, y, where it passes through the
lower partition, X.
If now it is desired to apply the brake air is admitted to the train pipe, A, and
thereby the Piston Valve is tightly pressed on its scating, y', thus cutting off the

page_text: Communication between the automatic pipe, A, and the reservoir end of the brake
Cylinder, C, at the same time the air flows into the central chamber, 2, through the
small flap valve, X, in the lower rigid partition, X.
When a vacuum is again created in the automatic pipe, A, of an intensity just
exceeding one fourth of that of the vacuum now existing in the brake Cylinder, C.,
and therefore acting on the lower and smaller end of the piston valve, y³, the air
in the central chamber expanding raises the diaphragm and attached piston valvo
and thus reopens communication between the automatic pipe A, and the reservoir
end of the brake Cylinder, C., causing equalization of the vacuum in the cylinders
and train pipes and releasing the brakes in one fourth of the time which would
otherwise be necessary.
Then the two holes, X", and X³, will again be opposite each other, the central
chamber, 2, will therefore be exhausted and the vacuum on both sides of the flexible
diaphragm, y', being equal, the piston valve will descend by gravity to its normal
position.
The piston valve may if preferred be placed horizontally or otherwise, a spring
being used to replace gravity for closing the valve.
The piston valve is made to fit the hole in the boss of the lower rigid partition
well, and no packing is used, hence there is little or no friction for the piston to
over come. It must be understood that the holes, X2, X³, are not essential for the
working of the piston valve, but are merely used to obtain a more speedy
exhaustion of Chamber, 2, after the piston has lifted and so released the brakes.
Figure 7, is a Sectional Elevation and Figure 8 a plan of the Exhaust Check
Vale, [sic] v, being a Valve box, b, b, the branch pipes leading respectively to the
Cylinder and supplemental pipe, v', being a ball valve of wood or other suitable
material coated with India rubber, v².
Figure 9 is a front Elevation and Figure 10 a section at centre of the hose
Coupling. h, is the nozzle of the Coupling to which the hose pipe is attached, ' is
an india rubber packing ring held in place by the ferrule, h³ h³, h³, are the clip
levers which engage with the flange of the opposite coupling and are kept up tight
by the springs, h. To separate the Coupling the clipping levers are depressed
so as to clear the flange and the coupling drawn apart. In the event of a break
away upon a moderate pull coming on the hose pipes, the clips would slip off the
flanges and the Couplings be parted without damage. On every Vehiclo double
blank Couplings will be fitted to which the Couplings of the train pipes will be
attached at the rear of the train.
"
In place of the hinged spring lever catches fixed clips may be used, the back of
the flange being slightly inclined so that when the Couplings are put together the
Clips passing through recesses in the flanges made to receive them, a slight turn
will suffice to cause the clips to grip tightly and so maintain an air tight joint.
These clips would in the case of separation of the train also disengage themselves
by slipping off the inclined plane on which they rest.
Another form of coupling is shewn in Figure 14 in which ', is one end of a
hose coupling terminating in a conical metal nozzle provided with a Stop flange at
the larger end of the cone. is a double conical union socket with a rubber
lining, . Each hose Coupling end is provided with one of theso union sockets,
which, when not in use, hangs suspended from it by a chain, , or other convenient
attachment.
When it is required to couple a train pipe the nozzle on either side is thrust
into the double conical union and in order to prevent its coming apart accidentally
or otherwise an elastic metal or rubber safeguard, 1, fixed at its centre to the
middle of the union socket, is provided having loops or eyes at its ends, which are
drawn over hooks situated on the under side of the coupling ends. The rubber
lining of the union socket would be made preferably with ribs around its
interior circumference lying parallel to the bases of the cones.
If preferred cones with the rubber lining may form the termination of the hose
coupling and the loose union may be double conical Sections with their larger ends

page_text: united and in this case the union would be inserted in the coupling ends in stead
of the Coupling ends being inserted in the union socket
These joints also will come apart without injuring the hose coupling in case of
accidental division of the train.
Figure 11 is a Sectional Elevation and Figure 12 a Sectional Plan, on line Z. Z.
of the drivers valve for working the brake. A is the automatic pipe, B, the
supplemental pipe and O the pipe leading to the exhaust apparatus n. is the body
of the valve in which works the hollow plug valve, n³, open at the bottom and
having an opening n², in the side. n³ is a cap to keep the valve in position, n' is a
washer, n³ is the lever for working the brake and n an opening for admitting
air to the train pipe A. The normal position of the Valve is that shewn on the
drawing in which there is free communication between the exhaust apparatus and
the train pipos.
The Exhaust of the Reservoir End of the brake cylinders is continuously carried
on by means of the Communication with the exhaust apparatus which is always
maintained through the Supplemental pipe, B. This enables the brake to be
applied in any degree, with any number of repetitions, or continuously when
descending long inclines and preserves throughout its automatic character with
undiminished power.
When it is desired to apply the brake the driver's valve is turned so as to close
the passage between the exhaust pipe, O, and the automatic pipe, A, a still further
turning brings the opening n³ opposite to that marked no and so admits air to the
automatic pipe A which causes the pistons to move in the cylinders and apply the
brakes.
$
To release the brakes the drivers valve is set back to its normal position and the
automatic pipe is again exhausted
Another part of my invention consists of an arrangement for warming and
drying the air required for applying the brakes before its admission to the train
pipes by causing it to pass through a heated chamber in order to heat it and
deprive it of its moisture and so prevent the accumulation of water and the risk of
its freezing in the brake apparatus
Another part of my invention relates to an improved machine for exhausting
air from the brake apparatus which may be termed the Compound Ejector but any
other exhaust apparatus may be used without departing from the nature of my
Invention. This is shewn in Figure 13 and consists of:-
A Vertical tube, ¹, slightly coned and Surrounded by a casing, k², for a Steam
jacket which is covered by some non-conducting material. This tube is Surmounted
by a chamber of larger diameter having a Steam inlet, -The train pipes are
connected to the top of this chamber by the pipe O, which is continued downwards
through the Steam chamber by the thin tube, k, which nearly closes the upper eud
of the vertical tube ³, leaving a small annular space for the admission of Steam.-
and, are respectively inlet and outlet connections for supplying the Steam
jacket Round the base of the vertical tube, kl, is an annular chamber, 7, provided
with a water inlet, ka, and continued downwards as a conical tube, P, The annular
Chamber is so arranged as to leave an annular space round the base of the
vertical tubo k' for the admission of water into the lower tube, k³.
This apparatus is placed at such a level on the Engine that the discharge nozzle
at the base of the tube, k, is never lower than the highest water level in the tender
or tank of the Locomotive.
The action of the apparatus is as follows;-Steam is admitted through the
inlet,, to the Steam chamber whence it rushes into and down the vertical
tube, k, drawing with it air from the pipe O. The Steam and air proceeding down
the lower tube, , draw in a supply of water through the inlet, ks, which is
connected with the tank or tender of the Engine. The Steam jacket around the
upper tube, k, maintains the temperature of the Steam admitted and so by
preventing condensation preserves its energy and enables it to draw the air down

page_text: the upper tube, k¹, with full velocity and establish an impetus. Upon the current
of mixed steam and air reaching the base of the tube, k, the addition of the water
-condenses the Stenm thus accelerating the impetus of the moving column and
consequently exhausting the air at a more rapid rate than when steam alone is
used. Under the base of the lower tube is a receptacle for the condensed
products of the ejector with a pipe to lead the same back to the Engine tank or
tender.
The heat absorbed by the water thus used as well as the Steam employed
are not lost, being returned to the tank as water at an increased temperature
Another part of my invention relates to a steam cock for automatically regulating
the action of the Engine Steam brake.
Of this steam cock Figure 15 is an Elevation, Figure 16 a Sectional Plan through
centre and Figure 17 an Elevation of the plug of the cock showing the outlet for
Steam Referring to the above mentioned figures is the body of the cock,
the plug working in it-the lever for turning the plug, actuated either directly
or indirectly by the piston rod of a vacuum cylinder, is the Steam inlet, 7³ the
outlet for Steam to the Engine brake, a Slotted hole in the plug always open
for the passage of Steam, is a pear shaped hole for admitting a variable quantity
of Steam to the Steam brake.
In connection with this part of the apparatus I provide also an ordinary cock
for discharging the contents of the brake cylinder. This is worked by a rod also
actuated by the vacuum cylinder passing through a friction clutch situated at one
end of a lever the other end of which is fixed on the spindle of the cock
The action of these two cocks is as follows-Upon air being admitted to the
automatic pipe and the pistons of the vacuum cylinders being set in motion the
piston rod actuates either directly or indirectly both cocks closing by its earliest.
motion, the discharge cock which being done the rod actuating it proceeds to slide
through the friction clutch as far as necessary, at the same time the admission
Steam cock is turned, the pear shaped hole, 77, admitting a gradually increasing
quantity of Steam until the brakes are applied with their full power.
When it is required to take off the brakes and the recreated Vacuuin moves
back the pistons towards their normal positions in the vacuum cylinders, the
receding piston rod actuates the Steam cocks in the reverse direction, first
opening the dischargo eock, the rod of which thereafter slides through tho
friction clutch for the rest of its motion and also closing the admission Steam
cock.
The advantage of this arrangement is the automatic application and release of
the Steam brake on the Engine in the same degree that the brakes are applied
and released on the vehicles composing the train
The action of the complete brake apparatus will now be described
The hose pipes must first all be coupled up those at the tail of the train being
placed upon the blank Couplings. The driver's valve must be in the position
shewn in Figure 11 in which the air inlet is closed, but communication open
between the exhaust and the train pipes.
The ejector must then be put in operation for a few seconds which will create
a vacuum throughout the whole of the brake apparatus. During the running of
the train the air pump or ejector, as the case may be, will maintain or augment
such a vacuum as is necessary to work the brakes.
When it is desired to apply the brakes, the Driver's. valve is turned so as to
close the communication between the Exhaust and the automatic pipe and admit
air to the latter. The pistons then move in the brake cylinders so as to cause,
through the levers and rods, the brake blocks to press against the wheels, and also
cause the Steam cocks to be turned so as to operate the Steam brake on the Engine.
At the same time the exhaust apparatus goes on adding to the vacuum in tho
reservoir end of the brake cylinders through the supplemental pipe, thus maintaining
the original power of braking the train

page_text: To release the brakes the driver's valve is turned back, closing the air inlet
and reopening the communication between the exhaust and the automatic pipe.
The driver's valve being now in its normal position both train pipes are in
communication, not only with the exhaust, but also with each other and the high
Vacuum in the Supplemental pipe at once exhausts some of the air from the
automatic pipe, equalizing the vacuum in the two train pipes. At the samo time
the ejector is set going and as soon as a vacuum just exceeding one fourth (or such
other proportionate amount as is determined on) of that existing in the brake
Cylinders has been created the differential piston valves open and the vacuum
throughout the brake apparatus of the whole train is thereby immediately equalised
and the brakes fully released.
The most rapid stop of the train may be made by working the ejector at the
same time that air is admitted to the automatic pipe.
Assuming the extreme case of their being no vacuum existing at the moment
when it is necessary to apply the brakes, by opening the air valve and starting
the exhaust the brakes will at once be put on though less rapidly than if a vacuum
had been previously provided throughout the train, but any such vacuum so
created would be retained in the brake cylinders and would be available in case,
for instance, of the train becoming divided, for automatically braking the train
and its parts, while on the other hand no other continuous brake yet known is
capable of doing so much.
Should any accident happen to the hose pipes or the train become divided, the
brakes would be instantly automatically applied throughout the train including
the Engine, the check valves in the connecting branches between the Supplemental
pipe and the reservoir ends of the brake cylinders ensuring ample vacuum being
retained to completely arrest the train and its parts.
It will be seen that while the brake is automatic under all Conditions yet there
is the advantage of being able to maintain or augment the brake power to any
extent and for any length of time without taking the brakes off, an invaluable
property in a brake for descending long and heavy gradients, or where repeated
light applications of the brake are necessary.
The Engine is fitted with two vacuum gauges, one on the automatic pipe and
the other on the supplemental pipe, by which latter the driver always sees the
precise vacuum existing at any time in the brake cylinders.
Each Guard's Van is fitted with a gaugo to shew the condition of the brake and
a valve for admitting air to the automatic pipe in case of necessity for the Guard
to stop the train.
"
It inust be understood that the brake is perfectly automatic and complete
without the supplemental pipe and the latter may be omitted without departing
from the nature of my invention.
The differential piston valve may be fitted to some forms of vacuum brake such
as those known as the "Sanders" and "Clayton."
Having now described the nature of my invention and the manner in which
the same is to be performed I wish it to be understood that I do not limit myself
to the precise details herein described and illustrated as the same may be varied
without departing from the nature of my invention.
But I claim as my invention of an "Improved Vacuum Brake apparatus for use
on Railway Trains";
First, Constructing, arranging, and working the parts of brake Cylinders and
their appliances for operating brakes on Railway Trains substantially
as herein before described and illustrated in Figures 1. 2. 3. 4. 5. 6. 7
and 8 of the accompanying drawings either with or without the pipe
and apparatus for Supplementing the vacuum in the brake Cylinders.
Second, The use, in combination with vacuum brake apparatus, of a valve
apparatus constructed and acting substantially as described with
reference to Figures 5 and 6 or any other similar valve apparatus
whereby a proportionally low vacuum is enabled to lift a valve against

page_text: the pull due to a proportionally higher vacuum in the brake cylinder,
and so equalize the vacuum existing in the brake cylinder and the train
pipe.
Third, The use of a brake Cylinder constructed and arranged substantially as
described with reference to Figure 2.
Fourth. The use of a moveable piston rod guide substantially as described and
illustrated in Figure 2 with special reference to the method of arranging
and fixing the rollers so as to cause the guide to move spirally.
Fifth, The method of packing the piston in the brake cylinder by means of rubber
rings pressed outwards by springs substantially and in the manner set
forth and illustrated in Figures 2 and 3.
Sixth, The use of a check valve consisting of a ball of wood or other hard substance
and coated with Some pliable material such as India rubber substantially
as described and illustrated in Figures 7 and 8.
Seventh, The use of Couplings constructed Substantially and in the manner
described and illustrated in Figures 9. 10 and 14.
Eighth. The use in connection with vacuum brako apparatus of a controlling or
regulating valve for working the brakes substantially as described and
illustrated in Figures 11 and 12.
Ninth. The construction and working of a compound ejector for creating the
Vacuum substantially as described and illustrated in Figure 13 with
special reference to the use of a warm jacket and the addition of water
for the purpose of Condensing the Steam and accelerating the exhaust
Tenth. The use of a drying chamber from which to draw the supply of air for
applying the brakes.
Eleventh. The use of a Second or supplemental train pipe for maintaining or
increasing the vacuum in the reservoir ends of the brake Cylinders, tho
branch connections with the latter being provided with check Valves to
retain the vacuum in the cylinders and preserve the automatic character
of the apparatus
Twelfth. The arrangements herein described of pipes, valves, cocks, cylinders and
passages whereby vacuum brakes are operated substantially and in the
manner set forth.
In Witness whereof I the said Arthur Samuel Hamand have hereunto set my
hand and seal this seventh day of November in the year of our Lord One Thousand
Eight Hundred and Eighty Threo
ADTITITD
STAHAN