IMPROVEMENTS IN CONTINUOUS BRAKES FOR RAILWAY TRAINS
Year: 1879

page_text: LETTERS PATENT to Thomas Gething Clayton, of Derby, in the County of
Derbyshire, Engineer, for the Invention of "IMPROVEMENTS IN CONTINUOUS
BRAKES FOR RAILWAY TRAINS."
aled the 18th April 1879, and dated the 14th February 1879.
PROVISIONAL SPECIFICATION left by the said Thomas Gething Clayton
at the Office of the Commissioners of Patents on the 14th February 1879.
THOMAS GETHING Clayton, of Derby, in the County of Derbyshire, Engineer.
"IMPROVEMENTS IN CONTINUOUS BRAKES FOR RAILWAY TRAINS."
My Invention relates to improvements in continuous brakes for railway trains,
whereby I obtain greater simplicity and efficiency and a more rapid application of
automatic vacuum brakes.
One part of these improvements consists of a cylinder hung vertically upon a
top centre or upon compound trunnions fixed to the upper part of the carriage
framing with a piston to work inside it, the rod of which is connected direct to the
lever upon the rocking shaft of the brake.
A second part of these improvements consists of an open ended cylinder placed
inside a large casing or chamber, which will surround and support the cylinder
and at the same time form a large space for a reserve of vacuum to be used when
required for applying the brake. This large casing or vacuum chamber is carried
by a trunnion on each side which rest upon brackets bolted to the underframe of
the carriage, thus allowing this vacuum chamber and the cylinder in it to oscillate
according to the radiation of the lever upon the rocking shaft.
By preference I make the working parts of brass or other anticorrosive metal,
so as to avoid rust, and thereby always insure a clean smooth working surface in
the cylinder.
The object of hanging the cylinder upon a central point at the top is to get a
direct and straight line pull when the brake is applied between that point and the
joint where the piston rod is connected with the lever of the rocking shaft, thus
providing by the oscillation or swinging of the cylinder for the radiation of the
lever of the rocking shaft either longitudinally or laterally, and thereby avoiding
side strain or any twist of the piston in the cylinder, andalso any scraping of the
Price G71

page_text: piston rod against the side of the hole in the bottom cover of the cylinder; a further
object for its vertical position is that from the weight of the piston and rod and
lever the brake will fall off of itself and remain so when not in use, thereby
_keeping the brake blocks away from the wheels without the assistance of springs or
other similar appliances.
Between the bottom cover of the brake cylinder and the main pipe running
-along-the-train-I-place_a_flexible_pipe, and exhaust the air out of the cylinder in
-the-ordinary-manner-by-an-air-pump-or-ejector-on-the-engine. I first draw the
-air-from-the-bottom-side-of-the-piston-which-ensures_the_brake_coming_off_the_
wheels either
when-standing-at-a-station-or-when-the-train-is-running,-and-then-
through a very small hole in the piston, such as that described in the Specification
to my Letters Patent No. 946, dated 8th March 1878, suck the-air from the top
side of the piston and the large chamber until the vacuum becomes equal on both
sides. I intend making use of the small hole above alluded to with these improve-
ments in the first place to graduate the pressure of the brake blocks on the wheels
as the train is coming to a stand, to prevent skidding and jerking and to let the
brake off to enable an engine man to start his train away from a station without
first having to create a vacuum to take it off and to facilitate the attachment and
detachment of carriages at stations, as more fully set forth in the Specification to
my Letters Patent No. 946, A.D. 1878.
When the brake is not in work, or when the cylinder is quite exhausted of air
on both sides of the piston and is ready for action, the piston will lie close down
npon the bottom cover of the cylinder; but when air is admitted from the main
pipe to the underneath side of the piston the pressure of the atmosphere will raise
the piston and apply the brake, and when the air is again exhausted through the
main pipe it will at the same time draw down the piston flat upon the cylinder
cover which will fill all vacant space, and as there will be no vacant or useless
space under the piston to be filled with air before the piston moves upwards the
rapidity of action and the power of the brake will be increased.
Further, I make the centre hole in the cylinder cover a little larger than the
piston-rod and put an india-rubber ring round the piston rod, so that when the
piston is held down on the cylinder cover by the vacuum (or by its own weight)
it so compresses the india-rubber ring that no air can get into the cyilnder; but
when air is let in below the piston by the engine man for the purpose of applying
the brakes, or by a fracture or separation of the pipes or couplings, the piston
instantly ascends, and then the air rushes in all round the piston rod and assists in
destroying the vacuum (which have held the brake off), thus greatly increasing the
rapidity and power of application.
Should there be any leakage of air in the pipes or couplings the piston would not
ascend on account of the equilibrium of vacuum above and below the piston through
the means of the small hole.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Gething Clayton in the Great Seal Patent Office on the 13th
August 1879.
THOMAS GETHING CLAYTON, of Derby, in the County of Derbyshire, Engineer.
"IMPROVEMENTS IN CONTINUOUS BRAKES FOR RAILWAY TRAINS."
One part of my present Invention consists of a cylinder hung vertically upon a
top centre, as shown in Figures 1 and 2 of the accompanying Sheet of Drawings,
or upon compound trunnions fixed to the upper part of the carriage framing, or
in other ways which substantially answer the same purpose, with a piston to work
inside it, the rod of which is connected direct to the lever upon the rocking shaft
of the brake.
Another part of my present Invention consists of an open ended cylinder with
piston, as shown in Figures 4 and 5, placed inside a large casing or chamber which
will surround and support the cylinder, and at the same time form a large space for
a reserve of vacuum to be in readiness when required for applying the brake. This
large casing or vacuum chamber with the cylinder and piston is carried by a
trunnion on each side, which rest upon brackets bolted to the underframe of the
carriage to allow it to oscillate according to the radiation of the lever upon the
rocking shaft.
'
Another part of my present Invention is to take what is commonly known as a
"Smith's vacuum sack" and fix it inside the brake cylinder or an inner casing, as
shown in Figure 6. The object of this arrangement is to dispense with the friction
of a piston and the necessity for lubrication.
The object of hanging the cylinder upon a central point at the top, as shown in
Figures 1 and 2, or upon compound trunnions, is to get a direct and straight line
pull when the brake is applied between that point and the joint where the piston
rod is connected with the lever of the rocking shaft, thus providing by the oscilla-
tion or swinging of the cylinder for the radiation of the lever of the rocking shaft,
either longitudinally or laterally, and thereby avoiding side strain or any twist of
the piston in the cylinder, and also any scraping of the piston rod against the side
of the hole in the bottom cover of the cylinder. A further object for its vertical
position is that from the weight of the piston and rod and lever the brake will fall
off of itself, and remain so when not in use, thereby keeping the brake blocks
away from the wheels without the assistance of springs or other similar appliances.
Between the bottom cover of the brake cylinder and the main pipe running
along the train I place a flexible pipe and exhaust the air out of the cylinder in the
ordinary manner by an air pump or ejector on the engine. I first draw the air
from the bottom side of the piston, which ensures the brake coming off the wheels,
either when standing at a station or when the train is running, and then through
the very small hole S in the piston, as shown in Figure 2 or 4, being such as that
one described in the Specification to my Letters Patent No. 946, dated 8th March
1878, and in combination with it, together with the holes shown through the sides
of the piston in Figure 5, or by an air passage from the top to the bottom side of
the packing ring on the cylinder side, suck the air from the top side of the piston
and the large chamber until the vacuum becomes equal on both sides. I intend
making use of the small hole above alluded to with these improvements, in the first
place, to reduce the pressure of the brake blocks on the wheels as the train is
coming to a stand to prevent skidding and jerking, aud for letting the brake off to
enable an engineman to start his train away from a station without first baving to
create a vacuum to take it off; and also to facilitate the attachment or detachment
of carriages at stations, as set forth in my Patent Specification No. 946 of 1878.
When the brake is not in work, or when the cylinder is exhausted of air on both
sides of the piston, and is ready for action, the piston will be close down upon the

page_text: bottom cover of the cylinder, but when air is admitted from the main pipe to the
underneath side of the piston the pressure of the atmosphere will raise the piston
and apply the brake, and when the air is again exhausted through the main pipe
it will at the same time draw down the piston flat upon the cylinder cover,
excluding all useless-space-and-as-there will be no vacant or useless space_under
the piston to be refilled with air before the piston moves upwards the rapidity of
application of the brake will be increased, and the maximum force will be the
sooner exerted on the brake-blocks.
Further, I make the piston-rod hole in the cylinder cover a little larger than the
rod.and without any stuffing box and put an india-rubber ring round-the piston--
rod, so that when the piston is held down on the cylinder cover by the vacuum (or
_ by its own weight) it so compresses the india rubber ring that no air can get into
the cylinder, but when air is let in below the piston by the engineman or guard for
the purpose of applying the brakes, or when a fracture or a separation of the pipes
or couplings takes place and admits the air, the piston instantly ascends and the air
rushes in round the piston-rod and assists in destroying the vacuum, thus greatly
increasing the rapidity of application. Should there be any leakage of air in the
pipes or couplings the piston would not ascend, because an equal vacuum would be
maintained above and below the piston through the sinall holes or passages.
In order to make the details of my improvements of continuous brakes better
understood I will now describe them as shown in the accompanying Drawings, upon
which similar letters of reference indicate similar parts where such parts appear or
may be seen in each of the Figures respectively.
Figures 1 and 2 represent the cylinder hung vertically in the centre at top by
means of the iron bar A resting upon the brackets B, which are bolted to the
carriage framing, and the clip or strap C which goes over the bar A, thus allowing
the cylinder to oscillate in either direction necessary to form a straight line between
the centre at C and the pin which connects the piston rod and the brake lever N
at D. The cylinder E may be made in the form of a tube and placed in between
the top and bottom cylinder covers, as shown, and may be made of any anti-
corrosive metal. F is an ordinary piston packed with leather or any other suitable
material; G is the piston rod, coated with brass or any suitable metal to prevent
corrosion; H is the rocking shaft with suitable levers and rods attached; J is the
connecting pipe between the bottom of the cylinder and the main pipe of the train;
and K is the pipe leading to the auxiliary reservoir for vacuum.
Figure 3 is an outside view of the vacuum chamber or casing M, shown in Figures
4, 5, and 6, which is carried on the side trunnions L resting on the brackets B. The
piston rod G is coupled to the brake lever Nat D, and as the brake lever N radiates
in its movement so the vacuum chamber or casing and cylinder oscillate on the
trunnions to correspond with it.
Figures 4 and 5 show the open ended cylinder E inside the vacuum chamber or
casing M, also the piston F which works up and down in the cylinder E. The
piston F in Figure 4 is an ordinary packed piston, but with a high june ring, as
shown, to keep the piston from twisting in the cylinder. The piston F-in-Figure 5-
is packed or made air tight by a solid round india rubber ring P, which as the
piston ascends or descends rolls between the sides of the piston and cylinder. At X
there is a recess round the piston, which is more distinctly shown by the enlarged
view, Figure 7, in which is placed the india rubber packing ring P, and then the
piston is pressed down to the bottom of the cylinder, when the instant the brake
is applied and the piston ascends the packing ring is rolled into the narrow space Y;
which compresses it sufficiently to cause it to bear the pressure of the air.
The groove or recess X is made round the piston below the straight line surface;
for the purpose of giving liberty to the packing ring, so that it may rectify or
replace itself in its proper position again should it have become displaced, and also
for the purpose of taking the compression off the packing ring when the brake is
standing out of use.
'
. . S indicates the small hole in the piston F, which is the same and for the saine

page_text: purpose as the small hole referred to in the Specification to my Letters Patent
No. 946 of 1878; and immediately below the packing ring P of piston F, in
Figures 5 and 7, there are a few small holes through the piston, pointed to by T, for
the purpose of more rapidly sucking the air from above the piston and out of the
large vacuum chamber." When the piston rises these holes are immediately covered
by the roller packing, and the power of the vacuum is thereby preserved in the
chamber or casing until destroyed by the leakage of air through the small hole S;
when the vacuum above has been entirely destroyed, the piston will of its own
weight descend to the bottom of the cylinder, and the holes will then be again
uncovered.
This arrangement of holes, after the brake has been applied, ensures the brake
being taken off again clear from the wheels, by the air ejector on the engine creating
a greater vacuum under the piston than there would be above it, until the holes
become uncovered, thereby drawing the piston down. The pipe J leads to the main
pipe. Figure 6 shows a vacuum chamber or reservoir, the same as M in Figures 4
and 5, carried on trunnions, and the piston rod is connected to the brake lever in
the same manner as shown in Figures 1 and 3; it has a cylinder or casing E fixed
inside the vacuum chamber M, and inside this cylindrical casing is fixed the india
rubber sack V, securely fastened air tight at the top to the casing E, and at the
bottom to the piston or disk F, which is a little slack in the casing. The air is
exhausted from the bottom of the piston or disk through the pipe J, and thence
through the little hole S, or through the little hole S and the valve W combined,
from the inside of the india rubber sack V and chamber M. After the air has been
exhausted, or partly exhausted, in the way above described, the brake is applied by
letting air in again under the piston or disk, which instantly rises and lifts the
lever N; the brake will then remain on either until the vacuum is destroyed by the
leakage of air through the small hole S, or until the engineman draws down the
piston or disk with the air ejector on his engine. By this arrangement of exhausting
the air from both the outside and the inside of the india rubber sack V, and then
letting it in again under the piston or disk, a continuous brake is made to work
automatically with one india rubber sack without friction and without lubrication.
If preferred the india-rubber sack V may be fixed in a separate cylinder or casing,
such as the casing E closed at the top, with an auxiliary reservoir for vacuum, in
which case the cylinder or casing E may be suspended from the top or carried on
trunnions. With a view to exhausting the inside of the sack V, and the vacuum
chamber or casing M, or an auxiliary reservoir connected therewith more rapidly, I
place in the piston or disk the valve W, which is of a very simple construction, so
loaded with a spring or otherwise as to resist the pressure of the atmosphere when
the brake is applied, and one that will remain closed until the piston or disk has
returned to the bottom of the cylinder or casing E, when the stalk or bottom part
of the valve comes down upon the cylinder cover, and is thereby lifted up, opening
a way for the air to be rapidly sucked out of the sack V and the chamber M by the
ejector or air pump.
Having now described and ascertained the nature of my said Invention, and the
manner in which the same is or may be performed, what
I claim as of my Invention, and as secured to me by the hereinbefore in part
recited Letters Patent is,-
First. The hanging of the brake cylinder and connecting to the brake lever,
substantially in the manner hereinbefore described, and shown in Figures 1 and 2
of the accompanying Drawings, and for the object as herein-before set forth.
Second. The placing of an open ended brake cylinder inside the vacuum chamber,
substantially as herein before described, and shown in Figures 4 and 5 of the accom-
panying Drawings.
"
Third. The combination, substantially as hereinbefore described and set forth in
connection with Figure 6 of the Drawing, of what is commonly called a Smith's
vacuum brake sack" within an air tight casing, for the purpose specified.
1

page_text: Fourth. The holes through the sides of piston, as pointed to by T in Figures 5
and 7, substantially as hereinbefore described, and for the purpose set forth.
Fifth. The recess round the piston, as pointed to by X in Figures 5 and 7, sub-
stantially as herein before described, and for the purposes set forth.
Sixth. Making-the-piston-rod.hole_in_the_cylinder cover an air inlet, by making
it larger than the rod and without a stuffing box, substantially as and for the purpose
hereinbefore described.
Seventh. The arrangement-of-the-valve. W in piston or disk F, as shown in
Figure 6, so that it may operate substantially-as-and-for-the-purpose hereinbefore
Witness,
J. CARNALL.
THOB. G. CLAYTON. (L.S.)