IMPROVEMENTS IN APPARATUS USED IN WORKING BRAKES ON RAILWAY TRAINS
Year: 1879

page_text: LETTERS PATENT to Richard David Sanders, of Birmingham, in the County of
Warwick, Mechanical Engineer, for the Invention of "IMPROVEMENTS IN
APPARATUS USED IN WORKING BRAKES ON RAILWAY TRAINS."
Sealed the 26th August 1879, and dated the 12th March 1879.
PROVISIONAL SPECIFICATION left by the said Richard David Sanders at
the Office of the Commissioners of Patents on the 12th March 1879.
RICHARD DAVID SANDERS, of Birmingham, in the County of Warwick, Mechanical
Engineer. "IMPROVEMENTS IN APPARATUS USED IN WORKING BRAKES ON
RAILWAY TRAINS."
My Invention has reference to brakes used on railway trains of the kind
commonly called continuous brakes, which said brakes are operated either by com-
pressed air, or by vacuum or exhaustion.
My improvements are applicable to the said brakes whether the pressure or
exhaust be employed to press the brake blocks upon the wheels or be employed to
hold the brakes out of action, the pressure of the brake blocks upon the wheels
being in the latter case effected by weighted levers or springs.
The principal objects effected by my Invention are simplicity in construction and
efficiency, and great rapidity in action.
The first part of my Invention consists of the following arrangement of parts for
effecting greater rapidity of action in the brakes than can be obtained when the
governing valves are actuated in the ordinary manner, that is, by a separate piston
and valves in a separate chamber placed between the reservoir and brake
cylinder.
I make the piston of the brake cylinder hollow, the interior of the hollow piston
rod being divided longitudinally into two independent passages. One of these
passages is open at top and bottom, its top being furnished with a valve by which
it may be closed, and its bottom end opening into the atmosphere. The second of
these passages in the piston rod is open at top and closed at bottom.
I fix a rod near the centre of the inner side of the cylinder cover, and pass the end
of the said rod into the second passage in the hollow piston rod, which passage serves
as a guide for the said rod. A recess or notch is made near the lower end of the said
ID 077

page_text: rod, and on that side of it on which the valve on the first named passage is situated.
Upon the piston making a slight upward movement the arm of the valve herein
before described engages in the notch or recess in the stationary rod, and the valve
is thereby opened, and compressed air allowed to escape from the cylinder. The
discharge of the compressed air is thus effected with great rapidity.
The second part of my Invention consists in an improved automatic valve to be
placed in the brake van or in any other convenient part of the train for admitting
air into the continuous pipe running along the train, so that air is admitted to both
ends or from as many points in the continuous pipe as may be required; by which
arrangement greater rapidity of action is obtained than when one opening only is
made in the continuous pipe.
The said automatic valve or apparatus consists of a piston or diaphragm enclosed
in a cylinder or chamber, which is connected with a small valve chamber on one
side of it. The said piston or diaphragm is connected to the lever of the valve in
the said valve chamber. The area of the piston. or diaphragm is much greater than
that of the valve, and a small hole is made in the said piston or diaphragm for
slowly equalizing the pressure on both sides of the piston, in the way described in
that part of the Specification of Letters Patent granted to me on the 30th day of
April 1874, No. 1522, which relates to signalling.
When the exhaustion in the continuous pipe and on one side of the piston or
diaphragm is slightly reduced, the pressure on the other side of the piston over-
coming that on the small arca of the valve, the piston rises and the valve is opened
and retained in its open position until equal pressure is again slowly restored on
both sides of the piston. A spring restores the piston to its normal position, thereby
closing the valve.
The first described part of my Invention may be made to work by vacuum or
exhaust, and the second described part by compressed air by modifications which I
do not consider it necessary here to describe.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Richard David Sanders in the Great Seal Patent Office on the 6th
September 1879.
RICHARD DAVID SANDERS, of Birmingham, in the County of Warwick, Mechanical
Engineer. " IMPROVEMENTS IN APPARATUS USED IN WORKING BRAKES ON
RAILWAY TRAINS."
My Invention has reference to brakes used on railway trains of the kind commonly
called continuous brakes, which said brakes are operated either by compressed air,
or by vacuum or exhaustion.
My improvements are applicable to the said brakes whether the pressure or
exhaust be employed to press the brake blocks upon the wheels or be employed to
hold the brakes out of action, the pressure of the brake blocks upon the wheels
being in the latter case effected by weighted levers or springs.
The principal objects effected by my Invention are simplicity in construction and
efficiency, and great rapidity in action.
The first part of my Invention consists of the following arrangement of parts for
effecting greater rapidity of action in the brakes than can be obtained when the
governing valves are actuated in the ordinary manner, that is, by a separate piston.
and valves in a separate chamber placed between the reservoir and brake
cylinder.
I make the piston rod of the brake cylinder hollow, the interior of the said
hollow piston rod being divided longitudinally into two independent passages.
One of these passages
open at both ends, one end being furnished with a valve
by which it may be closed; the other end opens into the atmosphere. The second
of these passages in the piston rod is open at one end and closed at the other end.
I fix a rod to the inner side of the cylinder cover and pass the end of the said rod
into the second passage in the hollow piston rod, which passage serves as a guide
for the said rod. A projection or enlargement is made near the free end of the said
rod. Upon the piston making a slight inward movement the arm of the valve
herein before described strikes against the projection or enlargement on the
stationary rod, and the valve is thereby opened, and compressed air or other fluid
pressure allowed to escape from the cylinder. The discharge of the compressed air
or other fluid is thus effected with great rapidity.
The second part of my Invention consists in an improved automatic valve to be
placed in the brake van, or in any other convenient part of the train for admitting
air into the continuous pipe running along the train, so that air is admitted at both
ends, or at as many points in the continuous pipe as may be required, by which
arrangement greater rapidity of action is obtained than when one opening only is
made in the continuous pipe for applying the brakes.
The said automatic valve or apparatus consists of a piston or diaphragm enclosed
in a cylinder or chamber which is connected with a small valve chamber on one
side of it. The said piston or diaphragm is connected to the lever of the valve in
the said valve chamber. The area of the piston or diaphragm is greater than that
of the valve, and a small hole is made in the said. piston or diaphragm for slowly
equalizing the pressure on both sides of the piston in the way described in that part
of the Specification of Letters Patent granted to Francis Sanders on the 19th day
of February 1873, No. 625, which relates to signalling, which said Invention was
communicated from abroad by me to him.
When the exhaustion in the continuous pipe and on one side of the piston or
diaphragm is slightly reduced, the exhaust on the other side of the piston or
diaphragm overcoming that on the smaller area of the valve, the piston or diaphragm
rises and the valve is opened and retained in its open position until equal pressure
is again. slowly restored on both sides of the piston or diaphragm.
A spring
restores the piston or diaphragm to the normal position, thereby closing the
valve.

page_text: The first described part of my Invention may be made to work by vacuum or
exhaust, and the second described part by compressed air by modifications which
are hereinafter explained.
I will now proceed to describe, with reference to the accompanying Drawings, the
manner in which my Invention may be performed.
Figure 1 represents in longitudinal section apparatus constructed according to the
first part of my Invention as applied to a piston and cylinder for working brakes
by means of compressed air or any other fluid pressure.
a is the brake cylinder, and a2 the piston of the said cylinder; b is the hollow
piston rod of the piston a², the interior of the said hollow piston rod b being divided.
longitudinally into two independent passages c, d.
· The passage d is open at both ends, its inner end being furnished with a valve e
by which it may be closed, and its outer end or discharge port at fopening into the
atmosphere. The other passage c in the piston rod b is open at its inner end and
closed at it outer end. g is a rod fixed to the cylinder cover, its end passing into
the passage c in the piston rod, the said passage serving as a guide for the said rod.
A projection or enlargement g² is made near the free end of the rod g. Upon the
piston b making a slight inward movement the arm e² of the valve e strikes against
the projection or enlargement g² on the stationary rod g, and the valve e is thereby
opened, and compressed air allowed to escape from the cylinder; the discharge of
the compressed air is thus effected with great rapidity. The compressed air from
the continuous pipe on the train enters the brake cylinder a at h and passes by the
cupped leather m of the piston, and through the small hole i in the piston a² until
an equilibrium of pressure is established on both sides of the said brake piston a².
The effective area of the piston rod side of the piston a² being reduced by the
area of the piston rod b, which is of large diameter, causes the said piston to be
forced to the outer end of its stroke by the excess of pressure on the non-piston rod
side of the said piston. The flange k on the piston rod b is thus brought into contact
with the india rubber or other suitable washer 1, and the pressure upon it due to
the difference of effective areas of the sides of the piston makes an air tight joint
whilst the piston is in the position shewn in the Drawing, which position keeps the
brakes from contact with the wheels.
The action of the apparatus is as follows:--When it is wished to apply the brakes
the pressure in the continuous pipe on the train and consequently on the non-
piston rod side of the piston b is slightly reduced until the pressure on the piston
rod side of the said piston b exceeds that on the other side. The piston is thus
caused to move inwards, which movement opens the valve e, as herein before
described, by which movement the remaining pressure in the cylinder a is imme-
diately discharged through the passage d in the hollow piston rod b and discharge
port f. It will be seen that if the continuous pipe on the train is closed after the
brakes have been applied, equilibrium of pressure will be gradually restored on both
sides of the piston by the flow of the said pressure through the small hole i in the
piston, which piston will gradually return to its normal position and release the brakes.
I lay no claim to the application of the small hole in the piston for the purpose of
equalizing the pressure on both sides of the piston, as the object attained is pre-
cisely the same as that described in that part of the Specification of Letters Patent
hereinbefore referred to, granted to Francis Sanders on the 19th day of February
1873, No. 625, which relates to signalling.
By constructing the parts of the apparatus in the manner described and illus-
trated, the brake piston a² itself operates the governing valve e for the discharge of
the pressure, and performs the same function as the separate piston which has been
adopted in other forms of pressure brakes for effecting the same or similar objects.
Simplicity and greater rapidity of action are thus obtained. As regards simplicity,
by dispensing with the separate piston, and as regards rapidity of action, by the
brake piston being the first part moved by the reduction of pressure in the con-
tinuous pipe on the train, when such reduction takes place for the purpose of
applying the brakes..
...

page_text: I make the ring a³ of the piston a³ and the gland 6% of the piston rod of such a
shape as to leave cavities as shewn at a³, 63, which cavities I fill with plumbago or
other solid lubricant, so as to avoid the necessity of frequently applying lubricants.
The cupped leather packing m of the piston and the bush n of the piston rod are
also made of a flexible composition containing a large proportion of plumbago and
lubrication in the ordinary way is thus rendered unnecessary.
Figure 2 represents in longitudinal section a modification of the arrangement
Figure 1, which modification is applicable when the brakes are worked by vacuum
in lieu of pressure.
In this arrangement the governing valve e is placed on the outside of the brake
cylinder a as represented, and the rod g is attached to the hollow piston rod b.
When the vacuum is equal on both sides of the piston a, the said piston is
forced inwards into the position represented by the pressure of the atmosphere
acting on the closed and external end of the piston rod b. In this position of the
piston the brakes are held out of action. On the admission of air into the con-
tinuous pipe on the train and to the non-piston rod side of the piston a², for the
purpose of applying the brakes, the piston moves outwards and the valve e is
opened by the action of the expanded end g of the rod g on the lever e³ of the said
valve e.
A sudden inrush of air then takes place and the brakes are rapidly
applied by the vacuum which is retained on the other side of the piston and in the
reservoir by the check valve p. Where it is desired to employ a pressure of air
greater than that of the atmosphere the valve e may open communication with a
reservoir of compressed air. I find however that air of atmospheric pressure
answers well in practice.
In this arrangement, the washer 7 is on the outside of the gland and the cupped
leather of the piston and the bush of the piston rod are reversed, but they are lubri- .
cated and constructed in a similar manner to the corresponding parts in Figure 1.
- Instead of the rod g which operates upon the governing valve being placed inside.
the brake cylinder and piston rod, it may be attached to the outside of the piston
rod, and Figure 3 shows a modification in which the rod is so placed outside. The
cylinder of the modification, Figure 3, is constructed to work with compressed air
or other fluid pressure, and is similar in its action to the arrangements shown in
Figures 1 and 2. The piston in moving carries with it the rod g, which rod
operates upon and opens the cock or valve q, which cock or valve is closed by the
spring as soon as the lever 8 which works the said cock or valve is disengaged
from the rod g, as indicated in dotted lines in Figure 3.
Figure 4 represents in section a modification of the apparatus, Figures 1, 2,
and 3; a is a collapsing cylinder inserted in a metal casing b. The piston rod c
hollow, and inside the said hollow piston rod c slides a tube d, which is attached.
to the end of the casing b and forms a guide for the hollow piston rod c during the
motion of the moveable head or piston of the collapsing cylinder a. The piston rod
being of large diameter the moveable head or piston of the collapsing cylinder is.
consequently raised and maintained in the position, represented, so long as the
vacuum' or pressure is equal inside the casing b and inside the collapsing cylinder a,
in which position the brakes are off. When the vacuum in the casing b is reduced
for the purpose of applying the brakes, the pressure of the atmosphere acting upon
the moveable head or piston of the collapsing cylinder a forces it down. The first
movement causes the valve e to be opened, essentially in the manner described with
respect to the arrangement Figure 3, and a rapid reduction of the pressure in the
casing bis thereby effected.
Figure 5 represents another modification in which the collapsing cylinder a is
suspended from the top of the central casing b. When the parts of the apparatus
are in the positions represented in the Drawing the brakes are off, the moveable
base or piston f of the collapsing cylinder being kept down by its own weight,
assisted if necessary by a spring. The piston rod in this arrangement is made of
small diameter. Upon the admission of air into the casing for the purpose of.
putting on the brakes, the collapsing cylinder base frises, and the first movement.

page_text: opens the cock or valve g, whereby air is freely admitted into the cylinder and the
brakes rapidly applied.
The said cock g is closed by a spring or weight in connection with the lever by
which the cock is opened.
Figure 6 represents in section my improved automatic valve for admitting air
into the continuous pipe at any part of the train at which such valves are placed.
By the application of these valves the continuous pipe is opened in several places
simultaneously, or nearly so, and a freer admission of air into the pipe is effected
than is the case where only one valve, usually on the engine, is opened.
b is a piston or diaphragm, having an area in excess of the area of the small
valve a.
The said piston or diaphragm is connected to the lever e, which operates
upon the valve a to force it open. A small hole c is made in the piston or
diaphragm b for slowly equalizing the vacuum on both sides of the piston or
diaphragm in the way described in the Specification of the before recited Letters
Patent.
When the vacuum in the continuous pipe is suddenly reduced for the purpose of
applying the brakes, the vacuum on the upper side of the piston or diaphragm b
overcoming that on the small area of the valve a the piston or diaphragm b rises,
and the valve a is forced open, thereby admitting air into the continuous pipe for
the rapid application of the brakes. The valve a is retained in its open position
until equal pressures are again slowly restored on both sides of the diaphragm
through the small hole c. As the equilibrium of the piston or diaphragm is being
restored the said piston or diaphragm is forced downwards into its normal position
by the spring d. The valve a is thereby closed and the continuous pipe may be
again exhausted for the purpose of taking off the brakes and restoring the power
in the reservoirs for operating the brakes.
When the vacuum in the continuous pipe is slightly reduced the equilibrium of
the diaphragm or piston is not destroyed sufficiently to open the valve a by reason
of the small hole c.
By the arrangement last described the brakes can when desired be applied with
moderate force, but in cases of emergency they may be applied with full force.
Figure 7 represents a modification of my improved automatic valve as arranged
for working with compressed air or other fluid pressure. The action of this valve
is the reverse of that described for working with a vacuum or exhaust, and its
action will be readily understood by reference to the Drawing, the parts of
Figure 7 being marked with the same letters of reference as corresponding parts in
Figure 6.
Figure 8 represents in longitudinal section a modification of the automatic valves.
described with references, Figures 6 and 7.
This modification resembles the construction of safety valve for which Letters
Patent were granted to George Sanders on the 19th day of September 1868,
No. 2897, which I communicated to him from abroad.
The Drawing shows an arrangement suitable where compressed air or fluid
pressure is used, but by slight modifications it can be used for vacuum without
essentially departing from the nature of the Invention.
In this arrangement a piston b is employed to operate the valve a instead of the
diaphragm used in the before described arrangements. The area of the valve a is
larger than the area of the piston b, so that when equal pressures act simultaneously.
on the underside of a and the top side of b the said valve a is kept firmly pressed
against its seat, as shown. The pressure from the continuous pipe e on the train
passes to the reservoir c through the small hole d, and thus acts upon the
piston b.
When the pressure in the continuous pipe is reduced for the purpose of putting
on the brakes with full force the compressed air in the reservoir c acting upon the
upper side of the piston 6 depresses the said piston and opens the valve a, and
allows the remaining pressure in the pipe e to escape through the ports f, as indi-
cated by the arrows. As the pressures upon the piston b and valve a are equalized

page_text: by the passage of compressed air from the reservoir c through the small hole d, the
said piston and valve are forced upwards by the spring g and the valve a again
seated for the purpose of allowing the pressure to be restored in the continuous
pipe for taking off the brakes.
Having now described the nature of my Invention and the manner in which tho
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 improvements in apparatus used in working
brakes on railway trains;-
First. Constructing, arranging, and working the parts of brake cylinders and
their appliances for operating brakes on railway trains, substantially as hercin before
described and illustrated in Figures 1, 2, 3, 4, and 5 of the accompanying Drawings,
that is to say, the construction and arrangements of parts described and illustrated
whereby the first motion of the piston of the brake cylinder is made to operate
upon a cock or valve, by the opening of which the introduction of atmospheric or
compressed air, or the escape of compressed air is immediately permitted and
the brakes brought into action with great rapidity, substantially as described and
illustrated.
Secondly. The automatic valves, substantially as hereinbefore described and
illustrated in Figures 6, 7, and 8 of the accompanying Drawings, for simultaneously
permitting the escape of compressed air (when the brakes are worked by compressed
air) from the brake apparatus at different parts of the train, or for simultaneously
permitting the entrance of atmospheric air (when the brakes are worked by vacuum
or exhaust) into the brake apparatus at different parts of the train, thereby rapidly
bringing the brake apparatus into action.
In witness whereof, I, the said Richard David Sanders, have hereunto set my
hand and seal, this Second day of September, in the year of our Lord One
thousand eight hundred and seventy nine.
Witness,
RICHARD SKERRETT,
Clerk to George Shaw,
Birmingham.
RICHARD DAVID SANDERS. (L.S.)