IMPROVEMENTS IN MECHANISM FOR ACTUATING RAILWAY BRAKES
Year: 1874

page_text: LETTERS PATENT to Edward, Dunning Barker, of 45, Bedford Row,
in the County of Middlesex, for the Invention of “IMPROVEMENTS IN
D"
Sealed the 26th February 1875, and dated the 29th September 1874.
PROVISIONAL SPECIFICATION left by the said Edward Dunning
Barker at the Office of the Commissioners of Patents, with his
Petition, on the 29th September 1874.
I, EDWARD DUNNING BARKER, of 45, Bedford Row, in the County
of Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MECHANISM FOR ACTUATING RAILWAY BRAKES," to be as
follows:-
―:
This Invention has for its object improvements in mechanism for
actuating railway brakes.
I connect the brake blocks on the opposite sides of the carriage by
cross bars, and I apply a cylinder and piston or their equivalents at-
the centre of these cross bars in such manner that by the admission of

page_text: fluid under pressure or by exhaust the two cross bars forming a pair
can be forcibly drawn together, and the brake blocks at their ends
pressed against the peripheries of the wheels on opposite sides. The
cross bars are suspended from the frame of the carriage by links in such
manner that in case of breakage of the gear the parts will remain sus-
pended, and will not fall upon the way.
In connecting the cross bars with the brake blocks I apply a self-
acting arrangement such as is described in the Specification of a former
Patent, granted to me, and dated 17th of September 1872, No. 2754,
to prevent the brake blocks receding from the wheels further than is
necessary.
SPECIFICATION in pursuance of the conditions of the Letters Patent'
filed by the said Edward Dunning Barker in the Great Seal Patent
Office on the 27th March 1875.
: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD:
DUNNING BARKER, of 45, Bedford Row, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of September, in
the year of our Lord One thousand eight hundred and seventy-four,
in the thirty-eighth year of Her reign, did, for Herself, Her heirs
and successors, give and grant unto me, the said Edward Dunning
Barker, Her special license that I, the said Edward Dunning Barker,
my executors, administrators, and assigns, or such others as I, the
said Edward Dunning Barker, my executors, administrators, and assigns, 1
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 King-
dom of Great Britain and Ireland, the Channel Islands, and. Isle of
Man, an Invention for "IMPROVEMENTS IN MECHANISM FOR ACTUATING
RAILWAY BRAKES," upon the condition (amongst others) that I, the said
Edward Dunning Barker, my executors or administrators, by an in-
strument in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Inven-.

page_text: tion, and in what manner the same was to be performed, and cause the
same to 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 Edward Dunning Barker, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
This Invention has for its object improvements in mechanism for
actuating railway brakes.
I connect the brake blocks on the opposite sides of the carriage by
cross bars, and I apply a cylinder and piston or their equivalents at
the centre of these cross bars in such manner that by the admission of
fluid under pressure, or by exhaust, the two cross bars forming a pair
can be forcibly drawn together, and the brake blocks at their ends
pressed against the peripheries of the wheels on opposite sides. The
cross bars are suspended from the frame of the carriage by links in such
manner that in case of breakage of the gear the parts will remain sus-
pended, and will not fall upon the way.
In connecting the cross bars with the brake blocks I apply a self-
acting arrangement such as is described in the Specification of a former
Patent granted to me, and dated 17th September 1872, No. 2754, to
prevent the brake blocks receding from the wheels further than is
necessary.
In order that my said Invention may be most fully understood and
dilennied into affect I will need to deseriba the Deanings

page_text: and at their lower ends they are coupled together in pairs by the cross
bars e, e.
For additional security in case of breakage the cross bars e are sus-
pended from the frame by light rods or links f, f; the links pass
through the bars and receive beneath them india-rubber blocks ƒ³, ƒ³,
which, whilst allowing freedom of play check vibration and rattling.
The blocks f¹ are supported upon metal discs, and keys are passed
through the rods beneath them. h is a cylinder; it is attached by the
forked rod i with one of the cross bars e. The cylinder contains a
piston, and the rod h¹ of the piston is pin jointed to the other cross bar e.
The cylinder and piston are thus held suspended by their connection
with the cross bars. There is a spring which tends to retain the piston
at the further end of the cylinder, and then the brake blocks are held
off the wheels; but when water is made to enter the cylinder beyond
the piston the spring is compressed and the bars e, e, are drawn
together; k is a flexible pipe adapted to bear a high pressure by it;
the cylinder h is put into communication with the supply pipe 7. At
the ends of the carriages the pipes are coupled throughout the train by
means of tubes of vulcanized india-rubber strengthened with canvas.
The pipes 1, 1, are kept full of water, and when it is desired to apply
the brakes pressure is applied to the fluid in the manner described
in the Specifications of former Patents granted to me (No. 587, in
the year 1869, and 2754, in the year 1872) or by other convenient
means.
.
By slight modifications, without departing substantially from the
arrangement shown, air or other fluid under pressure or exhaust may
be substituted for water under pressure. m is a cock for closing the
passage between the pipes k and 1, which may at times be necessary
when any of the parts are out of repair; thus, any one set of brakes
in the train may be put out of action without interfering with others.
Figure 4 shows to a large scale a section of the cylinder h, together
with the piston, piston rod, and spring. The cupped leather which
forms the water-tight joint is not shewn.
Figure 5 is a side elevation, and Figure 6 an end elevation showing
the arrangement which I employ to prevent the brake blocks receding
to an inconvenient distance from the wheels. m* is a link having an
elongated eye m³, and a fixed pin n passes through it so that the link.

page_text: is free to play to the extent only of the elongation of the eye. At its
further end the link has ratchet teeth m², and it passes through a guide
loop n attached to the hanger d. This guide loop carries a pawl o
which takes into the ratchet teeth m³. The pawl and the loop are both
held in a frame p, also shown at Figure 7, and in this frame is contained
an india-rubber block which nips them together. The block » abuts
directly beneath a small casting s in the form of a double hook, which
at one end catches upon the frame p, and at the other upon the guide
loop n*, but allowing some freedom for motion.
It will be seen that the link m* offers no impediment to the movement
of the brake block towards the wheel, its teeth passing the pawl if
necessary, but it prevents the block receding from the wheel beyond the
distance which the elongation of the eye admits. As the brake block
wears it will be compensated by the passage of a tooth beneath the
pawl. The brake block in addition to being pin jointed to the hanger d
is controlled at its upper end by a self-adjusting forked link t. This link
is pin jointed to the brake block, and surrounds the hanger d; it also
receives within it the small casting u and the coiled spring v. The
spring surrounds a pin u¹ fixed in the casting, and bears against the
back of the link which is perforated for the passage of the pin, and thus
prevents the top of the block from hanging on the wheel when the
brake is not in action. The casting u carries a pawl u* which takes into
the teeth; d* is a pin on the hanger supporting the link, and d** is
another pin to prevent the pawl becoming displaced. If the link / were
not so arranged, as the brake block became worn the top of the block
would be held too far off the wheel, causing the blocks when the brake
was off, to touch the wheel at the bottom; to obviate this, on the block
wearing sufficiently, on the application of the brake the pawl u³ will slip
a tooth on the forked link t, and the forked link t will thus be prevented
from holding the top of the block by means of the spring so far off the
wheel.
In place of a cylinder and piston well-known equivalents for these
instruments may be substituted, but the arrangement shown is preferred.
In place of arranging the four brake blocks of a set to nip one pair
of wheels, each brake block may be arranged to press upon a separate
wheel; but this arrangement will cause a strain to be thrown upon
the axle box guides, and consequently I prefer the arrangement which
the Drawing shows.

page_text: What I claim as my improvements in machinery for actuating railway
brakes is, the combination of a cylinder and piston or their equivalents,
with cross bars armed each with two brake blocks, arranged and operating
substantially as described.
I also claim the arrangement of mechanism for preventing the
brake blocks receding from the wheels further than is necessary, and
to compensate for the wear of the brake blocks, substantially as
described.
I also claim the general arrangement of the machinery, substantially
as described.
In witness whereof, I, the said Edward Dunning Barker, have
hereunto set my hand and seal, this Twenty-fourth day of March,
in the year of our Lord One thousand eight hundred and seventy-
five.
EDWARD D. BARKER. (L.S.)