IMPROVEMENTS IN BRAKES
Year: 1877

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
BRAKES." A communication from abroad by John Hardy and John George
Hardy, both of Vienna, in the Empire of Austria.
Sealed the 15th February 1878, and dated the 28th November 1877.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 28th November 1877.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN BRAKES." A communication from abroad by
John Hardy and John George Hardy, both of Vienna, in the Empire of Austria.
This Invention relates chiefly to what are known as vacuum brakes, that is to
say, brakes operated by atmospheric air acting upon one side of a piston or
diaphragm, from the opposite side of which the atmospheric pressure is removed by
the production of a vacuum, and it consists of improvements having for their
object,―
First. Providing apparatus for causing the brakes to be automatically put on as
soon as air is admitted voluntarily or accidentally into the pipes leading to the
vacuum brake apparatus.
Secondly. The provision of means for automatically regulating the supply of
steam to air ejectors of any kind of vacuum brake in such a manner that a
constant vacuum may be maintained in the pipes leading to the vacuum brake
apparatus.
And, Thirdly. The combination with friction wheels operated by the motion of
the vehicle of vacuum apparatus for maintaining the said wheels in suspension as
long as a vacuum is preserved in the pipes, but allowing them to drop into contact
with the railway carriage axle as soon as air is admitted into the said pipes.
In carrying out the first part of this Invention a reservoir is arranged on each

page_text: carriage, which reservoir communicates at one end with the exhaust pipe only and
at the other end with the valve box of a double piston valve communicating with
the exhaust pipe, with the atmosphere, and with the pipe leading to the vacuum
brake cylinder. The end of the reservoir communicating with the exhaust pipe
only is provided with a valve opening only towards the said exhaust pipe, but
closing as soon as the pressure in the exhaust pipe exceeds that in the said
reservoir. This reservoir is to be kept constantly exhausted, and its capacity is
preferably larger than that of the vacuum brake cylinder. The piston valve at the
other end of the reservoir is so constructed and arranged that as soon as air is
admitted into the exhaust pipe running along the train such valve will be
displaced, and will shut off the communication of the vacuum brake cylinder with
the atmosphere, and putting it into communication with the reservoir from which
the air has been exhausted will cause the piston in the vacuum cylinder to draw on
the brakes. The two portions of the double valve which are carried on one and the
same piston rod are constructed of different areas, the larger end working next
to the exhaust pipe, whilst the other or smaller end works in one end of the
reservoir.
The inner sides of the large and small piston valves are in communication with
the pipe leading to the vacuum brake cylinder. The said double piston valve is
arranged so that in one position the larger piston valve will close the com-
munication between the vacuum brake cylinder and the atmosphere, while the
small piston valve will open the communication between the vacuum brake
cylinder and the reservoir, whereas in the other or normal position the communi-
cation between the vacuum brake cylinder and the atmosphere will be open whilst
the exhausted reservoir will be closed.
The action of this automatic brake apparatus is as follows:-Before starting the
train a vacuum is produced by any well-known means in the exhaust pipe running
along the train. The valve at one end of each reservoir will open and allow each
reservoir to be exhausted until the desired vacuum is produced. As soon as the
vacuum in the exhaust pipe is less than that in the reservoirs the said valves will
close and preserve the vacuum produced therein.
The double piston valve, arranged at the other end of each reservoir, and
consisting, as before mentioned, of a large piston fixed at one end and a small piston
fixed at the other end of a piston rod, will now be in such a position that the end
of the exhausted reservoir will be closed by the small piston valve, while the large
piston valve will leave open in the piston chamber an aperture communicating with
the atmosphere. The vacuum brake cylinder will therefore now be in com-
munication with the atmosphere, and the brakes will be off the wheels. As soon
as air enters into the exhaust pipe running along the train, the pressure on one side
of the larger end of the double piston valve, neutralizing the pressure on the other,
the atmospheric pressure will force the smaller valve towards the reservoir, and
this being connected with the larger valve draws the latter with it, thereby closing
the aperture arranged in the piston chambers and cutting off the communication
with the atmosphere. As the small piston valve moves it will also open the
communication between the exhausted reservoir and the vacuum brake cylinder,
and the latter will thus be exhausted and the brakes be applied.
The second part of the said Invention relates to means for automatically
regulating the supply of steam to an air ejector, so as to constantly maintain a
vacuum in the exhaust pipes and their connections.
One mode of carrying out this part of the Invention consists in the employment
of two regulating vacuum cylinders of slightly different areas, the larger in direct
communication with the exhaust pipes, and the smaller in communication with the
said pipes by means of a valve opening outwards, the pistons of which cylinders
are connected to opposite ends of a rocking lever pivotted at its centre, and
arranged in relation to the pistons and in connection with the steam valve in such
a manner that so long as a sufficient vacuum is maintained in the larger cylinder

page_text: its piston will be at one end of its stroke, (say up for example), whilst the piston
of the smaller cylinder will be at the other end of its stroke, viz. (down in the
example assumed), but that, should the vacuum in the pipes be impaired, the
pressure acting on one side of the piston of the larger cylinder being partially
neutralized, such piston will be drawn down under the action of the smaller piston,
whereby the rocking lever will be caused to open the steam valve for the admission
of steam to the ejector until the normal vacuum in the larger cylinder is restored,
when its piston will be again elevated and the steam valve accordingly closed.
According to another modification a single regulating vacuum cylinder in com-
munication with the pipes may be employed, the piston of which cylinder is
connected by a suitable arrangement of levers or rods with the steam valve, so that
the action of the latter shall be regulated by the position of the piston of the vacuum
cylinder in such a manner as to ensure the maintenance of the normal vacuum, or
a compensation for leakage should such normal vacuum be temporarily impaired.
The third part of this Invention relates to vacuum apparatus for working the
friction wheels of chain, vacuum, hydraulic, or other brakes, which apparatus is
constructed in the following manner:-In communication with the exhaust pipes is
a vacuum cylinder, which is so arranged that its piston, held up by the atmospheric
pressure, shall maintain the said friction wheel suspended until the vacuum is
destroyed, either voluntarily or accidentally, when the friction wheel will fall into
contact with the carriage axle, and being thereby rotated will be caused to wind
up a chain or work pumps or exhausters for drawing on the brakes in the usual
manner.

page_text: 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 28th
May 1878.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN 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 that class of railway brakes which are operated
wholly or partially by the pressure of the atmosphere upon a piston working in a
cylinder, from which at the opposite side of such 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,―
First. Of a peculiar arrangement of apparatus, whereby the brakes are applied
automatically as soon as air is admitted either voluntarily or accidentally into the
pipes connected with the said apparatus.
Secondly. In the provision of efficient means for automatically regulating the
supply of steam to the air ejectors of vacuum brake apparatus.
And, Thirdly. Of a peculiar arrangement of apparatus for the purpose of rendering
truly continuous and automatic what are generally known as chain brakes, that
is to say, brakes which are applied by a force generated in one vehicle of a train,
and communicated to one or more vehicles by means of a chain connecting the
brakes on the vehicles.
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 Figures.
Figure 1 is a sectional detail view of a vacuum cylinder with its piston, both of
the construction and arrangement which it is preferred to adopt, but which in
itself forms no part of the present Invention, the same having been protected
by certain prior Letters Patent granted to me, dated December Fifth, One thousand
eight hundred and seventy-six, No. 4704.
Figure 2 is a sectional plan of apparatus arranged in connection with the said
cylinder for ensuring the automatic action of the brakes on the admission of air to
the exhaust pipe.
Figure 3 is a sectional detail drawn to a larger scale of one of the valves herein-
after referred to; and Figure 4 is a view in section shewing another kind of valve
which is not claimed separately as forming part of my present Invention, but
which may be used in place of Figure 3.
Figure 5 is a sectional elevation of an apparatus for automatically regulating
the supply of steam to the ejectors according to the second part of the said
Invention.
Figure 6 represents a longitudinal section of a portion of a brake van having
applied thereto the improvements which form the subject matter of the third part
of the said Invention according to one mode of carrying out the same; and
Figure 7 is a corresponding plan with the body of the vehicle removed.
Figure 8 is a longitudinal section illustrating another modification.
*
In carrying out the first part of the said Invention there are employed,―
First. Vacuum cylinders A, the pistons B of which are connected to the brake
blocks by any suitable arrangement of levers and rods.
Secondly. An exhausted reservoir or reservoirs E, herein-after designated
vacuum reservoirs," arranged in connection with the exhaust pipe, and with
the vacuum cylinders in such a manner that by the admission of air to such
pipe, either accidentally or voluntarily, a communication shall be automatically
established between the vacuum cylinder or cylinders, and the vacuum reservoir
or reservoirs at the same time that the communication between the latter and the

page_text: exhaust pipe is automatically closed, whereupon the vacuum cylinder or cylinders
will be partially exhausted, and the brakes will be accordingly applied under the
atmospheric pressure acting upon the exterior of their pistons.
The vacuum cylinders and their appurtenances, which may be of any suitable
description, are preferably as shewn of the construction described in the Specifi-
cation forming part of the said former Letters Patent, No. 4704 76. The cylinder A
is formed of two truncated cones A¹, A³, of a flat shape at both ends, and meeting
or united at their bases, such cylinder being constructed of open work at its end a,
and closed at its opposite end a¹. The piston B may consist as shewn of two
rigid discs b, b, constituting the piston head, which is as nearly as possible of the
same diameter as the head of the cylinder A, but fits loosely within it, and is
attached by the sack b¹ made of leather or other suitable material. The sack may
be attached to the piston head, either by being interposed between the two discs
which form the piston head and secured by rivets c, c, or in any other suitable
manner, so as to form a closed connection with the piston head at or near its
circumference, and the exterior edge or circumference of the sack is secured at b² to
the cylinder A at the point of junction of the bases of the truncated cones of
which it is formed, that is to say, at or about midway between the extremities of
the cylinder.
The piston B is connected to the brake levers and rods by means of a rod D,
which may be arranged in any usual or suitable manner.
It will be obvious from an inspection of the Drawing that on exhausting the air
from the interior of the cylinder A (which operation is effected by the outlet h
being placed in communication with the vacuum reservoir E, as herein-after
explained) the piston B will, by the pressure of the atmosphere acting upon its
exterior surface be forced into the cylinder, and caused to assume the position
indicated by dotted lines in Figure 1, and the brakes will be applied.
With the vacuum cylinders constructed as herein-before described are connected
the vacuum reservoirs and their accessories, which are interposed between the
vacuum cylinders and the exhaust pipes, and are constructed and arranged in the
manner next herein-after explained.
The vacuum reservoirs E, which are made, by preference, of a capacity about
3 times that of the corresponding vacuum cylinders which they are intended to
operate, are each provided with two valves g', h¹, respectively at opposite ends
thereof. The valve g¹ opens outwards, and through the intervention of a branch
pipe E' places the reservoir in communication with the exhaust pipe F leading from
the ejector or other air exhausting apparatus, so that under the action of the said
ejector or exhaust apparatus a vacuum will be produced in the reservoir whilst the
valve g will close should the pressure in the exhaust pipe exceed that in the
reservoir. The valve h¹, which opens inwards, is connected by a spindle h² with
a packed piston valve H (see Figures 2 and 3) of greater area, working in a
valve box H', a partition i, performed at k', being provided in order to form à
seating for the said piston valve H when closed. The valve box H¹ communicate's
at one end through the intervention of a branch pipe I with the exhaust pipe F,
and at its opposite end by means of the perforations and the branch pipe I' with
the vacuum cylinder A, and intermediately through an aperture with the
atmosphere.
The compound valve h¹, H, is so arranged that in one position (videlicet, that indi-
cated by dotted lines in Figure 3) the valve H will close the communications at k, k¹,
between the vacuum cylinder A whilst the valve h¹ will open the communication
between the vacuum cylinder A and the vacuum reservoir E, whereas in the other
or normal position (which is indicated by full lines in the Drawing) the com-
munications at h, k, between the atmosphere and the vacuum cylinder will be open
whilst the valve h', and consequently the communication between the cylinder and
the exhausted reservoir, will be closed.
This automatic brake apparatus is operated in the following manner:- One of
the vacuum reservoirs E and vacuum cylinders A being taken as an example of

page_text: the operation of the whole, before starting the train a vacuum is produced in
the exhaust pipe F, the valve g at one end of the reservoir E opens, allowing the
reservoir to be exhausted until the desired vacuum is attained, and closes when-
ever the vacuum in the exhaust pipe is less than that in the reservoir, thereby
preserving the vacuum produced in such reservoir. In this condition of the
reservoir the compound valve h¹, H, will be in the position indicated by full lines
in the Drawings, the reservoir being closed at that end by the valve h' whilst the
valve H leaves open the apertures h, k, communicating between the atmosphere
and the pipe I. The vacuum cylinder A will therefore now be in communication
with the atmosphere, and the brakes will be off the wheels. On the admission,
however, of air to the exhaust pipe F, either voluntarily under the action of an
attendant opening an air valve, or accidentally by the rupture of the exhaust pipe,
or from any other cause the atmospheric pressure on the outer side of the valve H
neutralizes or partially neutralizes the atmospheric pressure on the other or inner
side, and the pressure of the air contained in the valve box H' acting on the inner
side of the valve ¹ forces the valve into the reservoir E, and thus opens the
communication between the vacuum reservoir and the vacuum cylinder, at the
same time, the valve being connected with the valve H draws the latter with it,
thereby closing the apertures k, k', and cutting off the communication between the
vacuum cylinder A and the atmosphere. The vacuum cylinder is thus exhausted,
or partially exhausted, and the brakes are applied. In this position, which is
indicated by dotted lines in Figure 3, the parts will remain until the vacuum in the
exhaust pipe F and its branches is restored to such a degree that the pressure on
the outer side of the valve H is reduced sufficiently to allow that on the inner side
to produce the reverse action of the valve. When this takes place the valve H will
return to the position indicated by full lines in the Drawing, thereby closing the
valve, and placing the vacuum cylinder A in communication with the atmosphere
through the apertures k, k¹, when the brakes will consequently be removed from the
wheels.
The relative dimensions of the valves h¹, H, will be regulated by the degree of
sensitiveness required in the apparatus, that is to say, by the minimum degree of
pressure in the pipes at which it is desired that the brakes should be applied, as will
be well understood by persons skilled in the arts.
With the view of diminishing friction the modification of valve shewn in Figure 4
may be advantageously adopted, in which a sack H. having suitable rigid discs d, d,
and a suitable washer d is substituted for the rigid packed piston H, Figures 2
and 3. The dotted and full lines in Figure 4 indicate the same respective positions
of the valve as the corresponding lines in Figure 3, and the operation of the two
forms of apparatus is similar, the communication between the atmosphere and the
vacuum cylinder being either closed or open, according as the valve H is in contact
with its seat i, closing the apertures k', or is removed from its seat, leaving the said
apertures open, whilst the valve h¹ is open or closed as the case may be. The
valve may also be modified in the manner shewn in Figure 4, or in any other
suitable manner, so long as the proper proportion of its dimensions to those of the
valve H are preserved.
The second part of the said Invention, which is illustrated in Figure 5 of the
Drawings, relates to means for automatically regulating the supply of steam to an
air ejector, so as to constantly maintain a vacuum in the exhaust pipe and its
connections, and it consists in the employment of a regulating vacuum cylinder, such
for example as that shewn at A³, the piston B³ of which is connected by a lever
arm K with a cock L for controlling the ingress of steam proceeding from the
boiler by a pipe l, and its egress by the pipe m.
This cock may either constitute the steam valve for regulating the supply of steam
to the ejector, or as preferred it may be employed to control the admission of steain
to the slide or distributing valve of a small steam cylinder, the piston of which is
connected to and actuates the main steam valve for regulating the supply of steam
to the ejector. In either case so long as a vacuum is maintained in the cylinder A³,

page_text: the cock L will be closed, the piston B³ being in its highest position as shewn by
the full lines in the Drawing; but should the vacuum be impaired the piston B³ will
descend under the action of a spring n either to its lowest position, as shewn by the
corresponding dotted lines, or to a position intermediate between its two extreme
positions, according to the degree of deterioration of the vacuum, thereby opening
the steam-cock L, and admitting steam to the ejector until the vacuum is restored
to its required maximum, when the piston B³ will be again elevated by the atmos-
pheric pressure overcoming the force of the spring n, and the cock L accordingly
closed.
The vacuum cylinder A³ is held out of action when the air valve is opened by the
engine driver in order to apply the brakes, the air valve being connected with a stop
cock arranged in the pipe communicating with such vacuum cylinder, which stop
cock is closed by the act of opening the said air valve.
The third part of the said Invention is intended to remedy a defect which at
present exists in what are known as chain brakes, that is to say, brakes which are
applied by the winding up of a chain by means of friction wheels brought into
contact with the axle or other revolving portion of a carriage or guard's van.
These brakes are at the present time not in the true sense of the word either
continuous or automatic, and they are not under the control of the engine driver.
They are as a rule applied by the guard releasing by hand a weighted lever, which
brings the friction wheel into contact with the axle of the carriage; and inasmuch as
the power derived in this manner is only sufficient to operate the brakes upon a
limited number of carriages, it is obvious that in a long train the train is divided
into a number of sections by the guard's vans from which the brakes are applied, so
that the action is not simultaneous.
The breaking away of the train in like manner does not necessarily cause the
application of the brakes unless the guard's attention is drawn to the fact, and the
engine driver has no means before starting of ascertaining whether the brakes are
all in working order or of simultaneously applying them when required.
According to this part of the present Invention these defects are remedied, by
applying to the lever which sustains the weight in each guard's van, the vacuum
cylinder herein-before referred to, or what is known as Smith's vacuum sack, in
such a manner that when the air is exhausted from the cylinder, the lever which
keeps the friction wheels out of action is held in suspense, and the friction wheel is
thus maintained out of contact with the axle of the carriages.
For the purpose of effecting the exhaustion of the air from the cylinders in the
guards' vans, they are connected with the ejector on the engine by a line of pipes,
and whilst the train is in motion, the engine driver by means of the ejector main-
tains a vaccuum in the cylinders, and keeps the brake out of operation. It is
manifest that so soon as air is admitted into the pipes, either accidentally or inten-
tionally, the levers in the guards' vans are simultaneously and automatically released,
the friction wheels come into contact with the axles, and the brakes are forthwith
applied throughout the train.
In order to ensure the maintenance of the necessary vacuum to keep the brakes
out of operation, there is combined with the apparatus above-described under this
head of the said Invention, the apparatus herein-before described under the second
head of the said Invention, whereby the ejector is automatically set in operation
so soon as the vacuum in the pipes and cylinders falls below any desired point.
Figures 6 and 7, and Figure 8 illustrate respectively two modifications of this part
of the said Invention.
Referring to Figures 6 and 7, M is a friction wheel which is suspended at o, so as
to be capable of being moved into and out of contact with a collar or flange p on the
axle N of one pair of the wheels O of the carriage, and is connected by a rod O' and
a weighted bell-crank lever p¹ to the rod D' of the piston of a vacuum cylinder A*.
This cylinder communicates by an exhaust pipe F with the ejector situate on the
engine, and under the action of the said ejector a vacuum is produced in the cylinder
A, the vacuum being maintained at the required standard by means of the regu-

page_text: lating vacuum cylinder A³ described under the second head of the said Invention.
The piston of the cylinder A, and the parts connected therewith are so arranged
that so long as the vacuum is maintained in the pipe F, the piston will be
in its elevated position, and will hold the friction wheel M in suspension, as
shewn in the Drawing, but that when the vacuum is destroyed or sufficiently
impaired, either voluntarily or by accident, the friction wheel M will fail by the
gravitation of the weighted lever p¹ into contact with the collar or flange p on
the revolving carriage axle N, whereby rotatory motion will be transmitted to the
said friction wheel, which will be thus caused to wind up a chain P upon a drum Q
for drawing on the brakes through the intervention of rods q in any usual or suitable
manner.
In the modification illustrated by Figure 8, the friction wheel M with the drum Q
are made of sufficient dimensions, and so arranged that the wheel M shall be brought
into contact with the flange p on the axle N without the aid of additional weight
so soon as the atmospheric pressure on the under side of the piston of the vacuum
cylinder A is neutralized or partially neutralized by the destruction or sensible
deterioration of the vacuum in the said cylinder.
The full lines in Figure 8 denote a similar position to that indicated in Figures 6
and 7, and the dotted lines indicate the other position.
A chain r, Figures 6 and 7, leading to a lever within the reach of the guard, is
provided for the facility of applying the brakes by hand when necessary.
When desired, vacuum reservoirs are provided, situate on the engine or guards'
vans, or both, and with which the exhaust pipe F may be placed in communication
so as to facilitate the maintenance of the vacuum without the liability of the position
of the piston of the cylinder A4 being materially influenced by a slight leakage in
the cylinders or their connections.
Having now described and particularly ascertained the nature of the said Inven-
tion, and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion that 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. The combination of parts consisting of a vacuum cylinder or cylinders, and
a vacuum reservoir or reservoirs constructed and arranged and fitted with accessories
so as to operate substantially in the manner and for the purposes herein-before
described, and as illustrated by Figure 2 of the Drawings, the compound valve
being such as is shewn in Figure 3 or as is shewn in Figure 4, or any equivalent
valve.
Secondly. The employment of a vacuum cylinder for automatically regulating
the supply of steam to the air ejectors of vacuum brakes, substantially in the manner
herein-before described.
Thirdly. The combination of parts constituting brake apparatus, wherein a chain
brake is worked by a system of vacuum cylinders, pipes, and automatic regulating
apparatus combined, substantially as herein-before described, so as to render the
action of such chain brakes continuous and automatic.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, the Twenty-eighth day of May, One
thousand eight hundred and seventy-eight.
J. HENRY JOHNSON. (L.S.)