AN IMPROVEMENT IN THE CONNECTION OF PIPES FOR COMMUNICATING FLUID PRESSURE TO WORK BRAKES ON RAILWAY TRAINS
Year: 1883

page_text: LETTERS PATENT to Charles Denton Abel of N° 28 Southampton Buildings,
Chancery Lane, in the County of Middlesex for an Invention of "AN
IMPROVEMENT IN THE CONNECTION OF PIPES FOR COMMUNICATING FLUID
PRESSURE TO WORK BRAKES ON RAILWAY TRAINS »
communicated to him
from abroad by George Westinghouse Junior of Pittsburgh, Pennsylvania,
United States of America.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 13th November 1883.
CHARLES DENTON ABEL of N° 28 Southampton Buildings, Chancery Lane,
in the County of Middlesex "AN IMPROVEMENT IN THE CONNECTION OF PIPES
FOR COMMUNICATING FLUID PRESSURE TO WORK BRAKES ON RAILWAY TRAINS
"
[communicated to him from abroad by George Westinghouse Junior of Pittsburgh,
Pennsylvania, United States of America]
When the brakes of a railway train are worked by fluid pressure communicated
by pipes extending throughout the train, these pipes have to be connected from
carriage to carriage by flexible hose or multiple jointed pipes so as to allow for the
oscillations of the carriages relatively to one another. These flexible pipe connections
are liable to injury and deterioration, particularly when flexible hose pipes are
used, and when rupture occurs of any one of them the working of the brakes
throughout the train is seriously deranged or altogether prevented. In the case of
the brakes being automatic, the rupture of one of the connections has the effect of
putting on all the brakes of the train, which, in certain circumstances, might be
productive of serious accidents; and when the brakes are non-automatic, the
rupture of a connection prevents the brakes from being worked at all, and therefore
involves very serious danger. This invention relates to means of providing
against such occurrences. For this purpose, instead of a single hose or a single set
of jointed pipes for connecting from carriage to carriage, two separate hose pipes or
[Price 6d1

page_text: two separate sets of jointed pipes are arranged to extend from a valve box on the
one carriage to a similar valve box on the next carriage. The valve box in each
case has a middle chamber communicating with the metallic pipe that is fixed on
the carriage, and has two lateral branches communicating respectively with the two
flexible pipes. These branches are governed by a duplex valve, which, in its
middle position, closes neither branch, but can move to close either but not both at
the same time. When both connections are sound, the valve being subjected to the
same pressure in both directions, has an indifferent position, leaving both branches
open for free passage of fluid along the train pipe. But when either connection
gives way, then, owing to the difference of pressure in the two connections, the
valve is moved so as to close the unsound passage:
In some systems of pneumatic brakes, their working is effected by compressed
air, the pressure in the train pipe being usually greater than the atmospheric
pressure. In such cases the valve is in the middle chamber of the valve box,
capable of moving a little either way so as to seat against the inner face of either
of the lateral branches, and it is conveniently made in the form of a ball resting on
guides. In other systems of brakes, their working is effected by vacuum, the
pressure in the train pipe being below that of the atmosphere. In such cases two
valves connected by a guided stem are employed, so that the one or the other can
seat against the outer face of the lateral passage in which it is situated. In both
cases, a small hole or groove through the valve or seating is provided to allow of a
little leakage for the purpose of establishing equality of pressure in the two
connections while they remain sound, otherwise one of the passages might happen
to be closed by its valve and to remain closed. Each of the two hose or flexible
pipes on one carriage may have its own coupling, by which it is connected to the
corresponding pipe on another carriage. It is preferred, however, to simplify the
operations of coupling and uncoupling by employing a single intermediate coupling,
each half of which has attached to it a valve box of the kind described, the
middle chamber opening to the coupling, and the two lateral passages being
governed by the duplex valve and communicating with the two flexible pipes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Denton Abel in the Patent Office on the 12th May 1884.
CHARLES DENTON ABEL of No: 28 Southampton Buildings, Chancery Lane
in the county of Middlesex "AN IMPROVEMENT IN THE CONNECTION OF PIPES
FOR COMMUNICATING FLUID PRESSURE TO WORK BRAKES ON RAILWAY TRAINS
"
A communication to me from abroad by George Westinghouse Junior of Pittsburgh
Pennsylvania, United States of America
When the brakes of a railway train are worked by fluid pressure communicated
by pipes extending throughout the train, these pipes have to be connected from
carriage to carriage by flexible hose or multiple jointed pipes so as to allow for the
oscillation of the carriages relatively to one another. These flexible pipe connections
are liable to injury and deterioration, particularly when flexible hose pipes are
used, and when rupture occurs of any one of them, the working of the brakes
throughout the train is seriously deranged or altogether prevented. In the case of
the brakes being automatic, the rupture of one of the connections has the effect of
putting on all the brakes of the train, which, under certain circumstances, might
be productive of serious inconvenience and even danger, on account of the
unexpected stoppage of the train; and when the brakes are non-automatic, the
rupture of a connection prevents the brakes from being worked at all and therefore
involves very serious danger. This invention relates to means of providing
against such occurrences. For this purpose, instead of a single hose or a single
set of jointed pipes for connecting from carriage to carriage, two separate hose pipes,
or two separate sets of jointed pipes are arranged to extend from a valve box on
the one carriage to a similar valve box on the next carriage. The valve box in
each case has a middle chamber communicating with the metallic pipe that is fixed
on the carriage and has two lateral branches communicating respectively with the
two flexible pipes. These branches are governed by a duplex valve, which, in its
middle position, closes neither branch but can move to close either by not both, at
the same time. When both connections are sound, the valve, being subjected to
the same pressure in both directions, has an indifferent position leaving both
branches open for free passage of fluid along the train pipe. But, when either
connection gives way, then, owing to the difference of pressure in the two
connections, the valve is moved, so as to close the unsound passage.
In some systems of pneumatic brakes, their working is effected by compressed
air, the pressure in the train pipe being usually greater than the atmospheric
pressure. In such cases, the valve is in the middle chamber of the valve box,
capable of moving a little either way, so as to seat against the inner face of either
of the lateral branches, and it is conveniently made in the form of a ball resting
on guides. In other systems of brakes, their working is effected by vacuum, the
pressure in the train pipe being below that of the atmosphere. In such cases, two
valves, connected by a guided stem are employed, so that the one or the other can
seat against the outer face of the lateral passage in which it is situated. In both
cases a small hole or groove through the valve or seating is provided to allow of
a little leakage for the purpose of establishing equality of pressure in the two
connections while they remain sound, otherwise one of the passages might happen
to be closed by its valve and to remain closed. Each of the two hose or flexible
pipes on one carriage may have its own coupling, by which it is connected to the
corresponding pipe on another carriage. It is preferred, however, to simplify the
operations of coupling and uncoupling by employing a single intermediate coupling
each half of which has attached to it a valve box of the kind described the middle

page_text: chamber opening to the coupling and the two lateral passages being governed by
the duplex valve and communicating with the two flexible pipes.
DESCRIPTION OF THE DRAWINGS
Fig 1. is a longitudinal section and fig 2 is a transverse section of the valve box
for brake pipes having internal pressure above that of the atmosphere. Fig. 3 is a
longitudinal section and fig 4 is a transverse section of the valve box for brake
pipes having internal pressure below that of the atmosphere The middle chamber A
of the valve box communicates by a branch B with the fixed pipe of the carriage.
Each of the branches C C is made as a nozzle to receive on it one of the flexible
hose connections which forms the communication to a corresponding branch C or C¹
on the next carriage. When jointed pipes are used instead of flexible hose, the
branches C C¹ are made of suitable form to connect to the joints of the pipe. In
the sides of the middle chamber A are orifices having round them valve
seatings D D. The seatings in figs. 1 and 2 are internal to receive a ball valve E,
which is guided by ribs F along which it can freely move to seat itself either on D
or on D¹. When one of the flexible connections, such as that which is attached
to C, gives way, the pressure in that connection becomes immediately reduced
below that in A, and consequently the valve E seats itself as shewn in fig. 1, and
as the valve on the next carriage takes a corresponding position, the damaged
connection becomes thus cut off from the train pipe, the undamaged connection
with its valve orifices D¹ open, maintaining the continuity of the communication
throughout the train. The seatings D D¹ in figs. 3 and 4 are external and two
valves G G¹ are connected by ribs H which serve as guides so that the two valves
can move to or fro together. When one of the flexible connections such as that
which is attached to C, gives way, the pressure in that connection is immediately
raised above that in A where there is a partial vacuum, and consequently the
valve G seats itself, as shewn in fig. 3 and as the corresponding valve on the next
carriage also seats itself, the damaged connection becomes cut off from the train
pipe, the undamaged connection with its valve orifices D¹ maintaining the continuity
of the communication throughout the train.
It is possible that, when the increase of pressure above that of the atmosphere or
the reduction of pressure below that of the atmosphere is first effected, one or
other of the orifices D D¹ might be closed by the valve, and if this closure continued,
the closed connection would be useless. To prevent this from occurring, a little
leakage is allowed past the valve by cutting a small groove, such as L, in one of
the valve seatings or drilling a small hole, such as K, through one side of the
central chamber. The leakage through these small passages is sufficient to equalise
in a short time the pressure in the two branches, but not sufficient to interfere
with the working of the brakes, when either connection is closed by its valves, in
case of a damaged hose pipes.
By thus employing two sets of flexible connections from carriage to carriage,
instead of one set, the risk of the unexpected action or inaction of the brakes is
greatly diminished, as the simultaneous damage of both connections is highly
improbable. The use of duplicate connections might be objected to because it
involves a double operation in coupling and uncoupling them when the carriages
are brought together or taken apart. In order to remove this objection, the two
flexible or jointed pipes proceeding from the two branches C C¹ of the valve box of
one carriage, instead of extending to two separable couplings in the middle, and
thence to the corresponding branches of the valve box on the next carriage, are
connected to two branches of a similar valve box attached to one part of a single
separable coupling. Thus, in the connections from carriage to carriage there are
four valve boxes of the kind described, one on each of the two carriages, and one
on each half of the single separable coupling between the carriages. This
arrangement is shewn at fig. 5, where B¹ B' are the two valve boxes, one on each
of two coupled carriages, B³ B are the two similar valve boxes, one on each half of

page_text: the single separable coupling X and Y¹ Y² Y³ Y' are the two pairs of flexible hose
pipes, each pair connecting the valve box of a carriage to the valve box of the half
coupling. By this arrangement, all the advantages of the duplicate connections are
maintained without duplication of the coupling or uncoupling operation, there
being only one coupling to deal with between each pair of carriages.
It is sufficient to have the above mentioned leakage passage on one side only of
the valve box A, because, when the connections are arranged as shown at fig 5, the
leakage of B¹ will communicate with the branch y³ while that of B³, being on the
opposite side, will communicate with the branch y¹, so that, whichever side the two
valves may accidentally close on first charging the pipes, there will always
be a leakage either from B¹ into y² or from B³ into y'. This will, of course, also
be the case with the first described arrangement with the double coupling, as the
valve boxes being all made of the same hand, the positions of the leakage passages
will of course be reversed at the contiguous ends of the two carriages.
Having thus described the nature of this invention and in what manner the same
is to be performed, as communicated to me by my foreign correspondent I claim,
First: In combination with two sets of flexible hose or jointed, extending from
carriage to carriage, each set having its own intermediate separable coupling the
use of a pair of valve-boxes, each communicating with the fixed pipe of its carriage,
and each provided with a duplex valve substantially as and for the purpose herein
set forth.
Second: In combination with two sets of flexible hose or jointed pipes connecting
carriage to carriage with a single intermediate separable coupling the use of two
pairs of valve boxes each of the one pair communicating with the fixed pipe of its
carriage and each of the other pair communicating with one part of the coupling
and each provided with a duplex valve, substantially as and for the purpose herein
set forth,
In Witness whereof, I the said Charles Denton Abel have hereunto set my hand
and seal this twelfth day of May in the year of our Lord one thousand eight
hundred and eighty-four.
CHA³. D. ABEL (LS.)