IMPROVEMENTS IN RAILWAY CARRIAGE BRAKES
Year: 1872

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of,
"IMPROVEMENTS IN RAILWAY CARRIAGE BRAKES."-A communication
from abroad by Frederick Alexander Canfield, of Dover, in the
County of Morris, and State of New Jersey, United States of
America.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 18th June 1872.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN RAILWAY CARRIAGE BRAKES," to be
as follows:-
The brake blocks, which may be of wood or any other material used
for that purpose are attached to a flexible iron strap the ends of which
are fastened to the frame of the carriage or other vehicle, which strap
may be three inches wide and a quarter of an inch thick, more or less.

page_text: A vertical brake rod operated by a hand wheel at top has a screwed
lower end passing through a nut fixed to the frame of the carriage. Ou
the extreme end of this brake rod is attached a block having a groove
or channel cut in it lengthwise of the width of the iron strap, through
which groove the strap passes, and is secured by a pin from falling out.
The end of the brake rod is inserted in this block in a socket so arranged
that the rod can revolve without turning the block, and can raise the
block with it as it is raised. When the brake is not in use the brake
rod is screwed upward, carrying with it this block and also lifting the
strap, the effect of raising the strap being to lift the brake blocks and
relieve the wheels from all restraint. When it is desired to apply the
brakes the wheel of the vertical brake rod is screwed down, carrying
with it the strap and the brake blocks, and throwing a part of the
weight of the carriage upon the brakes, which weight can be increased
to any desired extent by diminishing the pitch of the screw, and
increasing the diameter of the wheel of the brake rod.
I am aware that brakes have been used in which the suspended straps
carrying the brake blocks have been depressed by a lever operated by
the hand or foot of the brakesman, but this arrangement has been found
defective, and the present Invention consists in the combination of the
brake strap with a screw operated by a brake wheel, which makes this
form of brake reliable.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 16th December 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of June, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-fifth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Alexander Melville Clark, Her special licence
that I, the said Alexander Melville Clark, my executors, administrators,
and assigns, or such others as I, the said Alexander Melville Clark,

page_text: my executors, administrators, and 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 RAILWAY CARRIAGE BRAKES," a communication to me from abroad by
Frederick Alexander Canfield, of Dover, in the County of Morris, and
State of New Jersey, United States of America, upon the condition
(amongst others) that I, the said Alexander Melville Clark, my executors
or administrators, by an instrument in writing under my, or their, or one
of their hands and scals, should particularly describe and ascertain the
nature of the said Invention, 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 Alexander Melville Clark, 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, reference being had to the accom-
panying Drawings, and to the letters marked thereon (that is to say)
A represents the body of a railway truck of ordinary construction,
such as is used for the transportation of coal; B, B, are the wheels, of
which it has four; C, C, are the brake blocks which may be of wood
or any other material used for that purpose. These blocks are attached
to the flexible iron strap D, the ends of which are fastened to the frame
of the truck at the points E, E. This strap may be three inches wide
and a quarter of an inch thick, more or less; F is a vertical brake rod
which is operated by the wheel G, upon the lower end of which is a
screw H passing through a nut I which is fixed to the frame of the
truck or carriage. On the extreme end of this brake rod is a block K
having a groove or channel cut in it lengthwise of the width of the
iron strap D, through which groove the strap passes and is secured by
a pin from falling out. The end of the brake rod is inserted in this
block in a socket so arranged that the rod can revolve without turning
the block, and can raise the block with it as it is raised.
When the brake is not in use the brake rod is screwed upward
carrying with it the block K, and lifting also the strap D which is

page_text: *secured in the 'block by a pin or otherwise, so that it will be carried
up with the block. The effect of raising the strap will be to lift the
brake blocks C, and relieve the wheels from all restraint.
When it is desired to apply the brakes the wheel G is screwed down,
carrying with it the strap D and the blocks C, C, throwing a part of the
weight of the carriage upon the brakes, which weight can be increased
to any desired extent by diminishing the pitch of the screw and
increasing the diameter of the wheel G. This arrangement can be
modified in a great variety of ways without altering the principle of
operation, the form here shown being a simple arrangement for coal
trucks in which the brakes arc applied to one pair of wheels only.
.
I am aware that brakes have been used in which the suspended straps
carrying the brake blocks have been depressed by a lever operated by
the hand or foot of the brakesman, but this arrangement has been found
defective. The combination of the brake strap with a screw operated by
a brake wheel is the new arrangement, which makes this form of brake
reliable.
Having described the nature of the Invention, and in what manner
the same is to be performed, I declare that what I claim as the
Invention to be protected by the herein-before in part recited Letters:
Patent is, the combination of a metallic brake strap, substantially such
as described, with a screw rod operated by a wheel or handle, sub-
stantially as described, for the purpose of a railway carriage brake, as
described.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Sixteenth day of December,
in the year of our Lord One thousand eight hundred and seventy-
Witness,
JAS. O. DEWEY,
53, Chancery Lanc,
London,
A. M. CLARK. (L.S.).