In- PROVEMENTS IN HYDRAULIC BREAKS FOR RAILWAY ROLLING STOCK, PARTLY APPLICABLY TO THE SUDDIVINA AD LANDED AD TEED TWIT ALLAD WALTER
Year: 1870

page_text: LETTERS PATENT to George Pearson Renshaw, of Park Valley, in
the County of Nottingham, Engineer, for the Invention of "In-
PROVEMENTS IN HYDRAULIC BREAKS FOR RAILWAY ROLLING STOCK, PARTLY
APPLICABLY TO THE SUDDIVINA
AD
LANDED AD TEED TWIT
ALLAD
WALTER
"
Sealed the 20th June 1871, and dated the 30th December 1870.
PROVISIONAL SPECIFICATION left by the said George Pearson
Renshaw at the Office of the Commissioners of Patents, with his
Petition, on the 30th December 1870.
I, GEORGE PEARSON RENSHAW, of Park Valley, in the County of
Nottingham, Engineer, do hereby declare the nature of my said In-
vention for "IMPROVEMENTS IN HYDRAULIC BREAKS FOR RAILWAY ROLLING
STOCK, PARTLY APPLICABLE TO THE SUPPLYING OF THE TENDER OR FEE TANK WITH
WATER," to be as follows:-
This Invention relates to a peculiar combination and arrangement of
mechanism for applying railway breaks by means of hydraulic pressure,
and is partly applicable to the supplying of the tender or feed tank

page_text: with water, and consists in the employment of a cistern containing
water or other liquid placed under the seat of the railway carriage
protected from the weather and filled from the outside.
A pipe connects the cistern with a hydraulic bellows, having vulca-
nized india-rubber strengthened with cloth for the covering or other
flexible material impervious to water. If the ends of the bellows
have an area of fifty square inches (which corresponds to 8 inches
diameter nearly,) and the head of water be two feet, the upper end
will have a lifting force of fifty pounds. This is multiplied say as 5 to 1
by a lever which actuates the break blocks. The bellows are ordinarily
empty, the water or other liquid being let out by an escape valve, but
when a cord extending along the train is tightened by a wheel in the
guard's van, or on the tender, or both, a lever is raised and depresses a
vertical rod which lifts the cistern valve with which it is connected and
admits the water from the cistern to the bellows by means of the pipe
before referred to. The exit or outlet valve from the bellows is then
kept closed till the cord is slackened. A small semaphore signal is
employed, which shows at the side of the carriage if any brake is not
properly taken off while the train is running. A weight serves to
depress the bellows, and so through the lever removes the breaks from
the peripheries of the wheels. The above sizes of parts give about two
hundredweight pressure on the break blocks, and the pipe is made of
sufficient sectional arca to allow this pressure to be applied by the
descent of the water very quickly. If greater pressure be required the
bellows may be increased in size, or the cistern placed higher in the
carriage so as to give a greater head of water, or (which I prefer) an
independent and similar bellows acting on the opposite side of the
carriage may be employed. These hydraulic brakes may be applied to
all or only some of the carriages in a train, and the cord may serve also
as the means of communication from the guard to the driver by being
connected with a whistle or gong in the usual manner.
the cistern valve and lowers the cord-actuated lever through the vertical
rod when the cord is slack.
•
A weight closes
When the train has to ascend heavy inclines a second cord similar to
the first, but secured at the ends may be used to raise the cistern valves
permanently by setting free detents or catches to keep the valves up.
This cord is stretched by the parting of the carriages if such should
accidentally occur on an incline.

page_text: A ram or piston action may be substituted for the bellows if desired,
and the ram may be packed so as to move water-tight by cupped leathers
as in the common hydraulic press.
It is also proposed to utilize the water discharged from each brake
bellows if desired, by collecting it in a suitable receptacle from which
it is raised or scooped up by a small revolving fan clamped on one of the
axles of the vehicle, hence it flows through a tube into the corresponding
receptacle of the next carriage before and so on to the tender for
supplementary use in feeding the boiler.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Pearson Renshaw in the Great Seal
Patent Office on the 30th June 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
PEARSON RENSHAW, of Park Valley, in the County of Nottingham,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Thirtieth day of December, in the
year of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said George Pearson Renshaw, Her special
license that I, the said George Pearson Renshaw, my executors, ad-
ministrators, and assigns, or such others as I, the said George
Pearson Renshaw, my executors, administrators, or assigns, should
at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN HYDRAULIC BREAKS FOR
RAILWAY ROLLING STOCK, PARTLY APPLICABLE TO THE SUPPLYING OF THE TENDER
OR FEED TANK WITH WATER," upon the condition (amongst others) that
I, the said George Pearson Renshaw, my executors or administrators,
by an instrument in writing under my hand and seal, should particu-
larly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to

page_text: be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Pearson Renshaw, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon (that is to
say):
My said Invention relates to a mode of applying hydraulic power
to the working of continuous brakes for railway rolling stock for the
prevention of accidents from collision, and for the more economical
working of the railway plant in such manner that cach carriage fitted
with my improvements shall give its own proportion of brake power to
the train and shall be capable of exerting such power independently of
the accidental failure of the brake apparatus of one or more of the other
connected carriages by negligence or otherwise. Also, so that the
train shall admit of being divided, and in which case the brakes in each
part will act separately.
as
The principal special advantages which I desire to secure are
follows, namely:-1. That the brakes shall admit of being applied by
either the guard or the engine driver, and whilst simple in construction
and not requiring frequent attention to keep them in working order
shall act powerfully and smoothly on the wheels of the carriages to
retard and stop the train. 2. That in the event of part of the train
becoming detached by reason of the severance of the couplings arti-
culating and connecting the several carriages, (and this particularly on
inclines) the whole of the hydraulic brakes shall at once apply them-
selves automatically to arrest the revolution of the wheels in the several
and disconnected fractions of the train. 3. That a given and pre-
concerted determinable pressure shall be applied to each respective
carriage wheel so as to obtain the maximum useful retarding force, and
this without the liability to wear and damage the tyres by sliding or
"skidding on the rails, or the risk of "chilling" and fracturing steel
tyres in frosty weather. And 4. That in trains taking on carriages at
junctions carriages not fitted with these special brakes shall admit of
being worked in conjunction with others so fitted.
"
And in order that my said Invention may be fully understood, I
shall now proceed more particularly to describe the same, and for that

page_text: purpose shall refer to the several Figures on the annexed Sheets of
Drawings, the same letters of reference indicating corresponding parts in
all the Figures.
Figure 1 (Sheet 1) of my Drawings is a longitudinal section and
partial elevation of an ordinary railway passenger carriage to which
my peculiar arrangement of hydraulic brake is fitted; and Figure 2
(Sheet 2) represents an end or transverse elevation of the same
carriage.
A is a cistern or reservoir supplied when necessary with water through
the nozzle or spout B. This cistern A may be conveniently placed
beneath the carriage seat, as shown, or at option it may be fixed on the
carriage back or roof, or in any other position, as desired, but always at
a sufficient elevation above the moving details of the brake to secure
hydrostatic power. The cistern A is connected with a small receiver C
by means of a pipe D, and also with the one or more pressure cylinders
One of these cylinders
or diaphragm chambers E, E, E, by the pipe F.
or chambers, is shewn in detail section on a larger scale at Figure 3,
and is herein-after more fully described. The cylinders or chambers E
are firmly attached to the framing of the carriage by an intermediate
framing, and on their tops are corresponding discs or covers G, G, G,
which are lifted through a small space when water from the cistern A
is admitted to the cylinders or chambers E through the supply pipe F.
Between the upper surface of each of the cylinders or chambers E and
the under surface of the corresponding disc G, a diaphragm of india-
rubber strengthened with cloth, or of leather, or other flexible material
impermeable to water is placed to prevent leakage. The discs G act
on the lever H which is counnected with one or more brake blocks I, I,
through the intermediate coupling rods or links shewn in the Drawing,
Fig. 1; but, if desired, the pressure cylinders or chambers E may have
their axes horizontal and so act directly on the brake blocks I without
the intervention of the lever H. I prefer however the first arrangement.
It will also be obvious that the disposition of the pressure cylinders or
chambers E with their attaching framing and of the other adjacent parts
severally may be varied to suit the general arrangement of the carriage
whether provided with brakes between the wheels requiring to be pressed
asunder and in opposite directions, or with brakes (as shewn in the
Drawings) which require to be pulled in the same direction. The hydraulic
power may also be applied on either one or both sides of the carriage

page_text: "
and equally to what are known as 'flap," or to "sliding" brakes. The
admission of the water to the pressure cylinders or chambers E, and the
consequent application of the brake blocks to the wheels is regulated
and governed by an inlet valve K, and there is likewise an outlet valve L
situated below on the same or a different rod, by which latter valve
the water may escape from the pressure cylinders or chambers E into
the catch trough or troughs M when it is intended to cause the breaking
power to cease. The brake blocks I are then removed from the wheels
by the combined weights of the discs G and lever H, supplemented if
necessary for that purpose. The valves K and L if on the same rod are
made cylindrical on a portion of their length, and filling the orifices in
their respective valve seats, and in all cases so that the exit valve L
may not open till the inlet valve K has closed in order to prevent a
waste of water. From the catch trough M the discharged water runs
through small apertures in the side of the fan casing N which surrounds
one of the running axles O of the carriage. This fan casing N is
suspended at one end from a cross bar which rests on the opposite axle
boxes by a rod made adjustable in length, and at the other end it is
hinged to the supply pipe F or other suitable part of the framing so as
to be able to rise and fall with the play of the springs. The fan
casing N may be cased in wood or other material imperfectly conducting
heat to prevent the freezing of the water in frosty weather, it should
also be put on the axle in two parts. A cock P is likewise provided by
which the water may be run off at such times as the carriage is required
to stand in a siding or other exposed place. The constant agitation of
the water, the normal state of emptyness of the pressure cylinders or
chamber E, and the short time the water remains in the catch trough M
however, will ordinarily be sufficient to secure immunity from injury to
the action of the brake at general temperatures, and in extreme cases it
will be easy to introduce sufficient boiling water to prevent the working
water from freezing. Within the fan case N a fan or dash wheel Q is
fixed by screw clamps on the carriage axle O and consequently revolving
with the latter. This fan by centrifugal force throws the water up one
or the other of the inclined spouts R, R, (according to the direction
of the motion of the train) and returns it to the original level in
the cistern A and the connected supplementary receiver C. Or
otherwise the discharged water may be used to supplement the supply
of feed water in the tender or tanks in the manner herein-after explained.
Or lastly, the escaped water may be allowed to run to waste. S, S, are

page_text: joints in the inclines covered with india-rubber rings to allow for play.
If necessary, the fan may be made to act as an ordinary centrifugal
pump raising the water up vertical pipes to the cisterns, but the
inclines shewn would seem more generally suited to the varying
velocities of a railway train, and the usual arrangements of the carriages.
Figure 3 shows one of the pressure cylinders or chambers before
referred to in section on an enlarged scale, a being the cylinder of cast
iron; the moveable disc or cover; c the connecting passage for the
water, and d the flexible diaphragm. The surfaces between which the
latter is compressed and secured may be roughened by being turned
with a coarse cut or left in rings in order to hold the flexible material
more firmly.
Figure 4 shows the arrangement of the cord for allowing the valve K to
admit water to the pressure cylinders or chambers E, and so apply the
brakes at the will of the guard or driver. This cord or other flexible
connection is passed over pulleys on the carriages from the guard's van
in the rear of the train to the tender or engine at its front in the same
manner as the commonly used cord communication between guard,
passengers, and driver. If any carriage in the train is not fitted with
the hydraulic brake the cord is simply passed by it and on to the next.
The cord is shewn passing under pulleys e, e, working the valve rods by
means of levers in such manner that when the cord is tense the inlet
valves K are kept closed, and consequently the pressure cylinders or
chambers E empty, and the brake blocks I off the wheels. And con-
versely when the cord is slackened a spiral spring for a suitable weight
then causing the inlet valves K to be opened, but all this arrangement
may be evidently reversed as the cylinders or chambers may be
ordinarily filled with water, and the cord normally slack, though
this alternative plan does not appear so expedient. The communica-
ting cord g is fastened at the one end around a wheel in the guard's
van by which it may be wound in to suit the length of the train
in the usual manner, whilst the other end is secured to the
periphery of a light wheel on the tender or engine, and around which it
is coiled, and either of these wheels is capable of being fixed or released
at pleasure by a detent h. A certain degree of strain or tension is kept
on the cord g by means of a tension weight and pulleys as shewn
in Fig. 4 or other suitable arrangement in the guard's van, and the
rapid opening of the inlet valve K and closing of the outlet valve L, and

page_text: consequent operation of the brakes is promoted by the spiral spring or
weight at f. If the cord g be broken by any of the carriages becoming
detached the valves will necessarily be actuated and the brakes applied
automatically in the same manner as by the ordinary slacking of the
cord by the guard or driver.
It is evident that the temporary application of the brakes by the
guard may be used by him as a signal to the engine driver, and also if
the cord be violently pulled down by an affrighted passenger it may be
made to cause a bell to strike similar to those fixed to give alarm by
raising the tension weight. Thus the same cord may serve for all
purposes of intercommunication in the train. In certain cases a small
stream of water may be diverted from the supply pipe F on to the brake
blocks to prevent them firing in hot weather.
To illustrate the power of the brake if we take the cistern A as con-
taining seven gallons or seventy pounds avoirdupois, of water (and
which will suffice for two consecutive actions) and the average head of
water (as the pressure will differ in the cylinders or chambers E) at two
feet, and also the diameter of each of the three pressure discs G at
eighteen inches, the net pressure on the brake blocks will be about
twelve hundredweight if the leverage at H is as two to onc. At T in
Fig. 1, is shewn a handle connected with the valves K and L in the
supply pipe F. This handle is to enable the porters or other attendants
of the train to shut the inlet valves K, and so prevent the operation of
the brakes whilst separating carriages from or adding carriages to the
train at stations, and the handle is capable of being fixed up by a pin
and chain to keep the valve K shut and the brakes off.
Fig. 5 shews an arrangement by which the water raised up either
of the inclines by the revolution of the fan runs from the one or the
other receptacle into the catch trough of the next carriage to be again
lifted and so transferred and caused to flow on till it reaches the feed
tank or tender to be used to supplement the supply for replenishing the
water in the boiler. The object of this arrangement is to supersede the
In short and what are
necessity for a separate tender in certain cases.
called "local" trains made up of a very limited number of carriages the
brakes throughout the train may be worked from the feed tank by means
of flexible pipes connecting the several carriages in lieu of providing
separate cisterns in the latter.
It will also be evident that some of the other details may be varied

page_text: according to circumstances without affecting the general principle of
their design, for example bellows like the well-known hydrostatic bellows
may be substituted for the cylinders or chambers with flexible diaphragms
or rams, or pistons may be employed as used in hydraulic presses.
But I have described the details as they would seem generally best adapted
for practical application.
Having now described and particularly ascertained the nature of my
said Invention 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,―
1st. The application of the natural pressure resulting from the super-
position of a head of water to actuate the brakes of railway rolling stock
by means of water admitted to cylinders or chambers with flexible
diaphragms or to bellows or other equivalent apparatus as herein-before
described.
2nd. The subsequent raising of the water so applied by means of fans
on the revolving axles of the carriages whereby such water after
having actuated the brakes can be either returned to the reservoir or
transferred to the tender or feed tank of the boiler as herein-before
described.
3rd. The working of the valves which operate the brakes by means of
cords or other flexible connections in such manner as to be under the
control of either guard and engine driver and generally of both, and so
as in the event of breakage of the connecting couplings of the train to
cause the breaks to act instantaneously and automatically as herein-before
described.
In witness whereof, I, the said George Pearson Renshaw, have to
this my Specification, set my hand and seal, this Twenty-ninth
day of June One thousand eight hundred and seventy-one.