IMPROVEMENTS IN APPARATUS FOR COMMUNICATING OR SIGNALLING BETWEEN PARTS OF RAILWAY TRAINS
Year: 1874

page_text: LETTERS PATENT to William Pinkerton, of Londonderry, in the
County of Londonderry, Ireland, Engineer, for the Invention of
"IMPROVEMENTS IN APPARATUS FOR COMMUNICATING OR SIGNALLING BETWEEN
PARTS OF RAILWAY TRAINS."
Sealed the 3rd November 1874, and dated the 4th May 1874.
PROVISIONAL SPECIFICATION left by the said William Pinkerton at
the Office of the Commissioners of Patents, with his Petition, on.
the 4th May 1874.
I, WILLIAM PINKERTON, of Londonderry, in the County of London-
derry, Ireland, Engineer, do hereby declare the nature of the said In-
vention for "IMPROVEMENTS IN APPARATUS FOR COMMUNICATING OR SIGNALLING
BETWEEN PARTS OF RAILWAY TRAINS," to be as follows, that is to say :-
"

page_text: .
locomotive in a position in which it can be most easily seen by the
driver. This indicator is formed with a circular or other conveniently
shaped case, and has fixed on a central arbor an index or pointer
arranged to sweep over a dial having marked on it the various com-
munications or signals that may be required. In general the following
will be found suitable, namely, "stop, all right, stop at station."
On the index arbor there is a ratchet wheel, having acting on it a
lever and spring pawl, which at each action gives the arbor and index a.
quarter of a turn (or other part of a turn according to the number and
arrangement of signals adopted). There is a spring holding catch,
which retains the arbor and index in any position to which it may have
been moved until released by means of a handle under the control of
the driver, and when released the index returns to its zero position by
the action of a weight or spring.
A steam whistle for drawing the attention of the driver is arranged to
be sounded by the mechanism working the indicator, and the action is
transmitted to such mechanism by levers and rods, links or shafts, which
are by preference arranged to pass overhead to the back end of the tender,
so as to be quite clear of the coals. At the back of the tender the
transmitting details are connected to a communicating cord extending
along the carriages, and arranged in a well-known way, each carriage.
having its separate length, which on making up the train is connected
to those of the next carriages. Each carriage is fitted with a small flag
stand, in which the rod of a flag can slide vertically. The flag rod can
be raised by a cord passing over a pulley, and thence down to a handle
inside the carriage, and when raised the flag is held up by a spring catch
gearing into ratchet teeth on the side of the rod. This holding-up catch
can be released by means of a cord, which is accessible to the guard
only. At the bottom of the flag rod there is a pulley, over which the
communicating cord is passed, and when the flag is raised this pulley
draws up a loop of the cord between two stationary guide pulleys.
With this arrangement the communicating cord can be pulled by the
guard at the back end of the train; or it may be acted on by a passenger
in any one of the carriages, the raising of the flag indicating the parti-
cular carriage in the latter case.
A passenger can only give one signal, which will cause the index on

page_text: same time; the guard however can give two or more signals by pulling
the cord so many times in immediate succession, which action whilst
sounding the whistle twice or oftener will move the indicator index two
or more stages from its zero point, and so show the desired signal.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Pinkerton in the Great Seal Patent.
Office on the 3rd November 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
PINKERTON, of Londonderry, in the County of Londonderry, Ireland,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of May, in the year
of our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, tl said William Pinkerton, Her special licence,
that I, the said William Pinkerton, my executors, administrators, and
assigns, or such others as I, the said William Pinkerton, 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
thercin expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, tho
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN APPARATUS FOR COMMUNICATING OR SIGNALLING BETWEEN PARTS OF RAILWAY
TRAINS," upon the condition (amongst others) that I, the said William
Pinkerton, my executors or administrators, by an instrument in writing
under my, or their, or one 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 Scal Patent Office within six calendar months next.
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Pinkerton, do hereby declaro
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

page_text: following statement in writing, reference being had to the accom-
panying Drawings, that is to say :-
My said Invention relates to improved and simplified apparatus for
communicating or signalling between parts of railway trains; and in
order that the nature of and manner of performing the same may
be properly understood, I hereunto append a Sheet of explanatory
Drawings or Diagrams to be herein-after referred to, and representing
parts of the apparatus I employ. In these Drawings the same reference
numerals are used to mark the same or like parts wherever they are
repeated.
Figure 1 is a sectional plan of indicating mechanism, and Figure 2 is a
front, clevation or face view of the same, but with parts of the dial shown
open so as not to hide the internal details. This indicating mechanism
is to be fixed on the locomotive, on the weather board, or in any position
in which it can be most easily scen by the engine driver. The indicator
is formed with a circular or other conveniently shaped case 1; and on a
central arbor 2, projecting through the plate 3 (Figure 1), and carried.
at the back by a bracket 4, there is fixed an index or pointer 5 arranged
to sweep over a dial, having marked on it the various communications
or signals that may be required. In general the following will be found
suitable, namely, "stop, all right, stop at station."
On the index arbor 2 there is fixed a ratchet wheel 6, having acting
on it a lever 7 and spring pawl 8, which at each action (imparted as
herein-after explained) gives the arbor 2 and index 5 a quarter of a turn
(or other part of a turn, according to the number and arrangement of
signals adopted). There is a spring holding catch 9, which, acting on
another ratchet wheel 10 fast on the arbor 2, retains the arbor and
index 5 in any position to which it may have been moved until released
by means of a handle 11 under the control of the driver. This handle 11
is on a spindle passing through the plate 3, and having two wipers or
arms 12 fixed on it in positions to act on the catch 9 and on the catch 8,
which latter is then in the same position as the catch 9. When the
catch 9 is relieved the index 5 returns to its zero position by the action
of a spring or of a weight 13 mounted on a stud, and formed with an
arc-shaped toothed rack 14 to gear with a pinion 15 fast on the
arbor 2.
A steam whistle 16 for drawing the attention of the driver is provided

page_text: may be variously arranged.
In the modification shown in the Drawings a horizontal spindle 17,
carried in small brackets attached to the weather board, has two arms or
levers fixed upon it, and one of these 18 is connected by a rod 19 to the.
pawl lever 7, by which the indicator mechanism is worked, the other
lever 20 being connected by a rod 21 to the parts by which the signalling
action is communicated from the rest of the train. The spindle 17 is.
shown as itself directly attached to the cock plug of tlie steam whistle 16,
but if preferred the whistle may be made with a lift valve, as is now
common, and such lift valve may be moved by a third lever on the
spindle 17. Each carriage of the train is to be fitted with a small flag:
stand 22 shown in sectional elevation in Figure 3, and made so that the
rod 23 of a flag can slide vertically in it. The flag rod 23 can be raised
by a cord 24, passing over a pulley 25, and thence down to a handle. 26.
inside the carriage; and when raised the flag is held up by a spring.
catch 27 gearing into ratchet teeth on the side of the rod 23. This
holding-up catch 27 can be released by means of a cord 28, which must
be arranged to be accessible to the guard only. At the bottom of the
flag 23 there is fitted a pulley 29, over which is passed a cord 30 forming
a part of the communicating cord extending along the train, and con-
nected to the indicator and other details on the locomotive, each carriage
being provided with its own separate length, which on making up the
train is connected to those of the next carriages. On the flag rod 23
being raised its pulley 29 draws up a loop of the communicating cord 30°
between two guide pulleys 31, and one end of the cord being held at the
rear end of the train the pulling up of the loop causes the mechanism
on the locomotive to be acted on. With this arrangement the com-
municating cord 30 can be pulled by the guard at the rear end of the
train, or it may be acted on by a passenger in any carriage fitted with
the flag apparatus; but in the latter case the raising of the flag will
indicate the particular carriage.
A passenger can only give one pull or signal, which will cause the
index 5 on the locomotive to point to "stop," the whistle 16 being
sounded at the same time; the guard however can give two or more
signals by pulling the cord 30 so many times in immediate succession,
which action, whilst sounding the whistle 16 twice or oftener, will move

page_text: the indicator index 5 two or more stages from its zero point, and so
show the desired signal.
Figure 4 is a Diagram showing a convenient arrangement of parts for
transmitting the communicating movement over the tender to the
locomotive, together with other details. The bell crank 32 may be
jointed to the rod 21, shown in Figure 2, and a chain or rod 33 may.
proceed from the upper arm of the bell crank to the back of the tender
at a height clear of any operations with coals on the tender. At the
back of the tender the rod 33 may be connected to a lever, to which can
be hooked the communicating cord 30 of the next carriage of the
train. The rod 33 is shown as also jointed to a bell crank 34 carried by
the tender, and to the other arm of this bell crank there is connected a
rod 35 working in brackets guides 36, and fitted with a stop at the
bottom, and with a weight 37 at its upper part. The stop checks the
moving of the rod 33 too far, and the weight 37 returns the parts to
their positions after each action, for which latter purpose a spring might
be used instead if preferred.
Having thus particularly described my said Invention, and the manner
of performing the same, I have to state that I do not restrict myself
to the precise details herein described or delineated, but that what. I
believe to be novel and original and claim as the Invention secured to
me by the herein-before in part recited Letters Patent is, the arranging
or combining together of the parts of apparatus for communicating or
signalling between parts of railway trains, substantially in the improved
manner herein-before described.
In witness whereof, I, the said William Pinkerton, have hereunto
set my hand and seal, this Thirty-first day of October in
the year of our Lord, One thousand eight hundred and seventy-
four