IMPROVEMENTS IN RAILWAY BREAKS
Year: 1872

page_text: LETTERS PATENT to John Clark, of 8, Belmont Terrace, North
Kensington, Parish of Kensington, County of Middlesex, Engineer,
for the Invention of "IMPROVEMENTS IN RAILWAY BREAKS."
PROVISIONAL SPECIFICATION left by the said John Clark at the
Office of the Commissioners of Patents, with his Petition, on the
7th May 1872.
I, JOHN CLARK, of 8, Belmont Terrace, North Kensington, Parish of
Kensington, County of Middlesex, Engineer, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN RAILWAY BREAKS," to
be as follows :—
The object of said Invention is to increase the power of railway breaks
by using compound levers combined with a self-adjusting take-up pawl
for compensating the wear of the blocks, and by arranging the
mechanism so that a series of several carriages can be worked at one
time either by the driver or guard of the train.
•

page_text: In carrying my said Invention into effect in practice I fit the carriage
with blocks, thrust rods, and rocking shaft in the usual manner; but in
the centre of the rocking shaft I fix a cast ratchet wheel with link on
cach side fitted with a take-up pawl to engage the said ratchet teeth.
I also fit a pair of links which press on the said wheel, and cause the
said pawl to mount into a fresh tooth when the blocks wear away by
using, thereby adjusting the blocks. I operate said pawl by compound
levers hung to the framing, and moved at their free end by a chain
carried in pullies attached to the carriage framing.
In operating a series of carriages at one time I join the said chains by
hooks, and by means of a windlass worked either by hand or by fric-
tional contact with one of the axles under the van or tender I enable the
driver or guard to apply the breaks of the several carriages at one time.
I also propose to make the said breaks self-acting by reversing the
action of said compound levers and depressing the free end by a back
weight or spring when the through chain is slackened. I also propose
to move the free end of said compound levers by atmospheric air or other
expansive gas, or by steam enclosed in a cylinder attached to the carriage
framing, and connected by a pipe with suitable couplings along the
train for operating several carriages at one time.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Clark in the Great Scal Patent Office on
the 7th November 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
CLARK, of 8, Belmont Terrace, North Kensington, in the Parish of
Kensington, County of Middlesex, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of May, in the year
of our Lord One thousand eight hundred and seventy-two, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Clark, Her special licence that
I, the said John Clark, my executors, administrators, and assigns, or
such others as I, the said John Clark, my executors, administrators,

page_text: 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 Islo
of Man, an Invention for "IMPROVEMENTS IN Railway Breaks,” upon the
condition (amongst others) that I, the said John Clark, my executors
or administrators, by an instrument in writing under my, or their, or onc
of their hands and seals, 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 John Clark, 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 :—
The object of said Invention is to increase the power of railway breaks
by using compound leverage combined with a self-adjusting take-up
pawl for compensating the wear of the blocks, and by arranging tho
mechanism so that a series of several carriages can be worked at one
time either by the driver or guard of the train.
In carrying my said Invention into effect in practice I fit the carriage
with block hangers, thrust rods, and rocking shaft in the usual manner;
but in the centre of the rocking shaft I fix a cast ratchet wheel with
link on each side fitted with a take-up pawl to engage the said ratchet
teeth. I also fit a pair of links which press on the said wheel, and cause
the said pawl to mount into a fresh tooth when the blocks wear away by
using, thereby adjusting the blocks. I operate said pawl by compound
levers hanging to the framing, and moved at their free end by a chain
carried in pullies attached to the framing.
In operating a series of carriages at one time I join the said chains by
hooks, and by means of a windlass worked either by hand or by fric-
tional contact with one of the axles under the van or tender I enable the
driver or guard to tighten the said chain, and apply the breaks of the
several carriages at one time. I also propose to make the said breaks
self-acting by reversing the action of the said compound levers, and
depressing the free end by a back weight or spring when the through

page_text: chain is slackened. I also propose to move the feec end of said com-
pound levers by atmospheric air or other expansive gas, or steam
enclosed in a cylinder attached to the carriage framing, and connected
by a pipo along the train for operating several carriages at one time.
In describing my said Invention more particularly, reference is made
to the accompanying two Sheets of Drawings.
DESCRIPTION OF THE DRAWINGS.
Sheet 1, Fig. 1, is an elevation; and Fig. 2 is a plan of a carriage or
van framing having one arrangement of my said Invention fitted thereto.
"A" are the blocks; "," the rocking shaft; "C," the thrust rods, all
which are done in the usual manner. Upon the rocking shaft I fit
a cast ratchet wheel "D" fitted with links "E" " and compound
levers "F." At the free ends of said levers I fit a pulley and back
weights, and along the centre line of the carriage I fit several
pullies "G, G," to carry the operating chain " 'H," shown by a dotted
line. The said chain is carried under the pulley in the levers, so that
by tightening the chain the levers are raised, and apply the blocks to
the wheels. "I" is a pawl to engage the teeth of the ratchet wheel.;
and "K" is a pressure block in connection with the self-adjusting
link "L,” which causes the pawl to mount into a fresh tooth as the
blocks wear away. The power to tighten the chain "H" is obtained
from a frictional wheel in contact with the axle. The said wheel is
forced into contact by the guard raising the operating lever "M,” and
depressing the bell-crank lever "N;" "O" is a spiral spring to soften
the frictional bite of the wheel. The said lever "N" may have also a
spring or back weight applied to it to force it into contact to enable the
driver to use the break without the aid of the guard by pulling a catch.
A similar arrangement may also be made with the levers "F" to make
the break self-acting in the event of the train breaking away on an
incline. When several carriages in a train are fitted to act as a con-
tinuous break the parts referred to by letters "A" to "L" are fitted in
the carriages, and the winding part referred to by letters "M," "N,” &
"O" are fitted in the van. The winding parts may also be fitted to the
tender to put the break under the control of the driver.
Sheet 2, Fig. 1, is an elevation; and Fig. 2, a plan of a carriage or
van framing having another arrangement of my said Invention. The
principal part of the fittings are the same as shown in Sheet 1, and are

page_text: lettered with similar letters, but the free ends of the levers "F" are
raised by a cylinder."M" charged by compressed air or steam. The
air or steam is conveyed along the train by a pipe joined by a flexible
coupling at each carriage. The compression is effected in a closed
chamber placed under the tender or other suitable place. The chamber
is shown in section under the carriage framing; it is fitted with a steam
pipe in connection with the boiler at one end, and with an air pipe in
connection with the train at the other end. A moveable disc or
diaphragm is placed inside to prevent the steam mixing with the air.
A two-way cock admits the steam when the break is required, and also
permits the condensed steam to escape from the chamber when the
steam has been shut off. One or more chambers may be used, as cir-
cumstances may require. A self-acting regulating valve may be applied
to the inlet two-way cock to shut off the steam when any required
pressure in the chamber has been attained.
Having now particularly described and ascertained the nature and
object of my said Invention, and the means I propose to carry the same
into effect and practice, I hereby further declare I do not absolutely
restrict myself to the several details shown and described, as from the
nature of the Invention these may be considerably modified in practise
without departing from the principles thereby illustrated, and upon
which my said improvements are based.
In witness whereof, I, the said John Clark, have hereunto set my
hand and seal, this Seventh day of November, in the year of
our Lord One thousand eight hundred and seventy-two.