IMPROVEMENTS IN RAILWAY BRAKES
Year: 1876

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
RAILWAY BRAKES." A communication from abroad by John Hardy and John
George Hardy, both of Vienna, in the Empire of Austria, Engineers,
PROVISIONAL SPECIFICATION left. by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 5th December 1876.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN RAILWAY BRAKES." A communication from abroad
by John Hardy and John George Hardy, both of Vienna, in the Empire of Austria,
Engineers.
This Invention relates more particularly to the pistons and cylinders of air brakes,
to the arrangement of separate pipes for exhausting the air from such cylinders on
the engine and tender and on the carriages, and to the couplings of such pipes.
The brake apparatus consists of a vacuum cylinder containing a piston packed
with a ring or disc of leather or other flexible material, as below described, and
when the air is exhausted from the cylinder the piston will by the pressure of the
atmosphere be forced into the same. The piston is connected by a rod with the
brake lever, so that the brakes will be applied when the piston is drawn into
the cylinder. The outer rim of the said ring or disc of leather or other flexible
material is fixed to the cylinder and the inuer part to the piston, which fits quite
loosely into the cylinder, so that, although the arrangement will be quite air-tight,
there will be no friction against the sides of the cylinder when the piston moves
to or fro.,
To guard against friction of the piston a piston rod running through the back or
upper end of the vacuum cylinder may be used. In this case instead of using a
stuffing box to pack such guide rod the hole may be covered by a cap long enough
to allow the play or stroke of the piston, this cap being cast or rivetted air-tight to
the cylinder. The ring or disc of leather or other flexible air-tight material forming
the packing between the piston and cylinder may be connected to both, in different
ways, without departing from the principal of this Invention.
One mode consists in fastening the flexible disc between two smaller iron discs

page_text: forming the piston, and then fastening the rim of the said flexible disc between the
flanges of two halves of the vacuum cylinder.
Another mode consists in making the cylinder of one piece, and fixing the outer
rim of the flexible disc to a ring to be then fastened or rivetted inside the cylinder.
The diameter of the flexible disc may be about two-thirds larger than that of the
iron disc forming the piston. By the above-described construction of piston and
cylinder a smaller and lighter cylinder may be used than heretofore in air brakes,
and the flexible packing will not be exposed to injury and be but little subject to
wear and tear.
The vacuum cylinder may be arranged vertically or horizontally to the brake
levers.
The connection of the ejector or air pump with the brake apparatus on the engine
and tender is effected by a pipe separate from that connecting the same ejector or
air pump with the brake apparatus on the carriages. By means of this arrangement
when the ejector or air pump is set in action the brakes will be applied to the
wheels of the engine and tender at about the same time and with as full power as
they will be applied to the last carriage of the train; the stopping of the train can
therefore be effected more quickly and without danger of the carriages running
together. By the above method, and in consequence of the small air space in the
cylinders, only one comparatively small pipe is required to run throughout the
train.
The couplings of the air pipes between the carriages are arranged so that should
the carriages separate by any accident cocks in the said pipes will be shut, so as to
keep the air from entering. This is effected by arranging on the end of each pipe
on each carriage a stop cock in such a manner that should the carriages separate
and the coupling hose be torn asunder this stop cock will be closed.
The coupling ends of the pipes are also arranged at some distance above the
buffers, so that the coupling pipes are out of the way of the buffers and coupling
chains.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 31st May
1877.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN RAILWAY BRAKES." A communication from
abroad by John Hardy and John George Hardy, both of Vienna, in the Empire of
Austria.
The said Invention relates to brakes operated by atmospheric air acting upon one
side of a diaphragm or piston working within a cylinder from which, at the opposite
side of such diaphragm or piston, the atmospheric resistance is removed by the
production of a vacuum by means of an ejector, air pump, or other suitable air-
exhausting apparatus, and it consists,―
1st. Of an improved arrangement and mode of combining together a diaphragm
or piston and a cylinder, such diaphragm or piston consisting of a rigid disc or discs
which fit loosely within a cylinder open at one end and closed at the opposite end,
and are packed with a ring or disc of leather or other suitable material attached at
its inner portion to the diaphragm or piston, and at its rim or periphery to the
cylinder, at or about the centre of the length of the latter, in such a manner that
when the air is exhausted the diaphragm or piston will be forced into the cylinder
by the pressure of the atmosphere, and the brakes to which the diaphragm or piston
is connected will be applied, a complete immunity from friction of the diaphragm or
piston against the sides of the cylinder being insured by reason of the loose fit of
the former therein, whilst at the same time an air-tight closure is obtained.

page_text: 2ndly. In the employment of two separate pipes or series of pipes leading from
the ejector, air pump, or other air-exhausting apparatus for exhausting the air from
the vacuum cylinders of the engine and tender and from those of the carriages
respectively.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the corresponding Figures.
Figures 1, 2, and 3, are sectional detail views of a vacuum cylinder with its
diaphragm or piston constructed, arranged, and combined together according to
three several modifications of the said Invention.
Figure 4 represents a side elevation with the near wheels removed of an engine
and tender with one of a train of carriages shewing two independent pipes or series
of pipes communicating one between the ejector and the engine and tender, and the
other between the ejector and the train of carriages, and also illustrating the
application of the vacuum cylinder.
Referring to Figures 1, 2, and 3, A is the diaphragm or piston consisting in the
examples illustrated of two rigid discs a, a, which fit loosely within the cylinder B
open at its end b and closed at its opposite end b', and are packed with a ring or
disc a of leather or other suitable material at its inner portion interposed between
and attached by rivets c, c, or otherwise to the discs a, a, and at its rim or periphery
at secured to the cylinder B at or about midway, that is to say, at or about the
centre of the length of the latter. The mode of constructing the rigid portion of
the diaphragm or piston, and of attaching the flexible portion or packing a¹ thereto,
may be modified in various ways, but in all cases it is essential that the diameter of
such rigid portion should be less than the internal diameter of the cylinder, or
when the cylinder is made of a taper form or varying size on its interior then that
the diameter of the rigid portion should be less than the internal diameter of the
said cylinder at the smallest part thereof. The flexible disc or packing a¹, the
approximate diameter of which is, say, about two-thirds greater than the diameter
of the rigid portion, may also be attached to the cylinder B in various ways.
In the Drawings, at Figures 1 and 2 respectively, there are shewn two modes of
attachment.
In the modification illustrated by Figure 1 the cylinder B is made in two
halves, B1, B3, between the respective flanges d, e, of which the rim or periphery a²
of the flexible disc or packing a is secured by boits f
In the modification shown in Figure 2 the body of the cylinder is made in one
piece and the rim or periphery a² of the flexible disc or packing a¹ is connected to
the cylinder B by means of a ring g and rivets for similar fastenings. The mode
of connection may however be otherwise varied, but in all cases it is essential that
the rin or periphery a² of the flexible disc or packing a¹ should be attached to the
cylinder B at or about midway, that is to say, at or about the centre of the length
of the latter.
The piston A is connected to the brake levers C (shewn in Figure 4) by means of
a rod D (Figures 1, 2, 3, and 4), which may be arranged either at right angles to
In order to
such levers, as shown in Figure 4, or in a line therewith, or otherwise.
further diminish any tendency to friction of the diaphragm or piston the rod D
may be provided with a tail or prolongation D¹ (Figure 3) extending through the
near or upper end or head b' of the cylinder B, whereby a guide is obtained for the
diaphragm or piston in its traverse. In lieu of employing a stuffing box with
which to pack such guide the hole in the head b¹ may be covered by a cap E either
cast (as shewn) or rivetted air-tight to the cylinder, and of sufficient length to
admit of the requisite stroke of the diaphragm or piston.
It will be obvious from an inspection of the Drawing that on exhausting the air
from the interior of the cylinder B through the outlet, to which the vacuum pipe
leading from the ejector, air pump, or other air-exhausting apparatus is connected,
the diaphragm or piston A will by the pressure of the atmosphere acting upon its

page_text: exterior be forced into the cylinder and caused to assume the position indicated by
dotted lines in Figures 1, 2, and 3, and the brakes F (Figure 4) will be applied.
The said Invention admits of the use of a cylinder of smaller dimensions and
lighter construction than it has been heretofore practicable to employ in air-brakes,
and by the improved arrangement moreover the liability to abnormal injury of the
flexible ring or packing is obviated, whilst at the same time a considerable
diminution is effected in the ordinary wear and tear.
Figure 4 illustrates a mode of carrying out the second part of the said Invention,
which consists in the employment of two separate or independent pipes or series of
pipes between the ejector, air pump, or other exhausting apparatus, on the one hand,
and the engine with its tender and the train of carriages on the other hand. In
the example assumed an ejector is represented as employed, but it will be obvious
that this part of the Invention is equally applicable when an air pump or other
air-exhausting apparatus is substituted for the ejector. G is the ejector; B, the
vacuum cylinder of one, H, of a train of carriages; and B¹, B¹, the vacuum
cylinders of the engine I and tender K.
It will be seen that the vacuum cylinder B of the carriage H is connected with
the ejector by means of a pipe L, whilst the vacuum cylinders B¹, B¹, of the
engine I and tender K are connected with the said ejector by another pipe L'
separate from and independent of the pipe L, which forms the communication
between the ejector and the vacuum cylinders of the train of carriages. By means
of this arrangement when the ejector, air pump, or other air-exhausting apparatus
is set in action the brakes will be applied to the wheels of the engine and tender,
and to the whole of the carriages, even to the last carriage of the train, nearly
simultaneously and with uniform maximum power. The motion of the train can
therefore be arrested more promptly and without liability to the concussion of the
carriages composing the train, whilst at the same time by the above method, and by
reason of the small air space in the cylinders, only one comparatively small pipe is
required to run throughout the train.
Having now described and particularly ascertained the nature of the said
Invention, and some modes of carrying the same into effect, I would observe in
conclusion that I am aware that it has been previously proposed to employ a
diaphragm or piston working loosely within a cylinder, and connected or secured
thereto by a flexible disc or packing, and therefore to this in itself I lay no claim,
but what I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,―
First. Connecting or securing the rim or periphery of the flexible disc or packing
of such diaphragın or piston to the cylinder at or about midway, or at the centre
of the length of the latter, substantially as and for the purposes herein-before
described.
Secondly. The employment of two separate or independent pipes or series of
pipes communicating the one between an ejector, air pump, or other air-exhausting
apparatus and the vacuum cylinders of the carriages composing the train, and the
other between such ejector, air pump, or other air-exhausting apparatus and the
vacuum cylinders of the engine and tender, substantially as and for the purpose
herein-before described.
Thirdly. The prolongation D' guided in the cap E, substantially as and for the
purpose herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this my Speci-
fication set my hand and seal, this Thirtieth day of May, One thousand
eight hundred and seventy-seven
J. HENRY JOHNSON. (L.S.)