AN INSTANTANEOUS, SELF-ACTING, AND CONTINUING ALARUM, ACTUATED BY ECCEN- TRIC OR RATCHET WHEELS, BUT REQUIRING NO END COUPLINGS, FOR THE PROTECTION OF PASSENGERS IN RAILWAY TRAINS
Year: 1864

page_text: LETTERS PATENT to John Clark, of the North London Railway Works,
Bow, in the County of Middlesex, Engineer, for the Invention of "AN
INSTANTANEOUS, SELF-ACTING, AND CONTINUING ALARUM, ACTUATED BY ECCEN-
TRIC OR RATCHET WHEELS, BUT REQUIRING NO END COUPLINGS, FOR THE
PROTECTION OF PASSENGERS IN RAILWAY TRAINS."
Sealed the 10th January 1865, and dated the 14th July 1864.
PROVISIONAL SPECIFICATION left by the said John Clark at the Office
of the Commissioners of Patents, with his Petition, on the 14th July
1864.
I, JOHN CLARK, of the North London Railway Works, Bow, in the County
of Middlesex, Engineer, do hereby declare the nature of the said Invention
for "AN INSTANTANEOUS, SELF-ACTING, AND CONTINUING ALARUM, ACTUATED BY
ECCENTRIC OR RATCHET WHEELS, BUT REQUIRING NO END COUPLINGS, FOR THE
PROTECTION OF PASSENGERS IN RAILWAY TRAINS," to be as follows, that is
to say:-
I propose to fix upon the axle or other moving part of the carriage a ratchet
or other wheel, which, on being turned, and the teeth or projecting parts
thereon coming into contact with springs, levers, or a sounding plate, box, or
board on the carriage, shall produce a vibrating, loud, sharp, alarming, and
continuous noise. The contact between the said ratchet or other irregularities

page_text: of the wheel and the sounding media being effected by a sharp pull or
pressure from any compartment or seat of the carriage. In place of using the
ratchet or other wheel, the same result may be obtained by pins or studs fitted
into or upon the axle. I also propose to operate the alarm mechanism by
means of an eccentric wheel, rotating in suspended bearings when brought
into contact with the carriage wheel. The said eccentric or other contact
wheels may be formed or fitted with a number of cavities charged with
detonating or explosive compound, so as to produce a succession of loud
sharp reports during the first rotation of the said wheels in putting on the
alarm.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Clark in the Great Seal Patent Office on the
14th January 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN CLARK,
of the North London Railway Works, Bow, in the County of Middlesex,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of July, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth 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, 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 "AN INSTANTANEOUS,
SELF-ACTING, AND CONTINUING ALARM, ACTUATED BY ECCENTRIC OR RATCHET
WHEELS, BUT REQUIRING NO END COUPLINGS, FOR THE PROTECTION OF PASSENGERS IN
RAILWAY TRAINS," 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 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 Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.

page_text: 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,
that is to say :-
This Invention has for its object the production of a passenger's safety
alarum signal for railway carriages, by which a means is provided for any
passenger instantaneously calling the attention of the guards and engine driver
as well as the other passengers in the adjoining carriages or compartment to
any carriage or particular compartment of any carriage of the train while in
motion, the particular seat from which the apparatus is used being thereby
also indicated.
The accompanying Drawing, which is laid down to a metrical scale of two
feet in an inch, shews a side elevation and transverse sectional view of a first-
class carriage, with the said apparatus as fitted thereto. The same letters
refer to the same parts in both Figs.
The roller a is drawn by a spiral or other spring towards the carriage
wheel, so that when the bolt 6, by which it is kept out of contact, is with-
drawn the spring brings the friction roller into contact with the running wheel
of the carriage. This roller is fastened to the lower end of a spindle or rod c, c,
which is carried inside a case close to the division of the compartment, so
as to be unseen and out of the way. On the top of the said spindle I
mount cross flexible arms d, d, with the small pellets e, e, at their ends, and
I place a sounding plate f, one end of which is free, within reach of these
pellets, so that when they revolve rapidly a very loud and incessant noise is
produced.
In order to give each passenger access to the alarm, I propose to place in
each seat of a first-class carriage a pull chain, wire, or cord in connection
therewith, terminating in a ring or loop, so that passengers, and particularly
ladies, may each pass an arm through the said ring or loop on taking
their seats, and thus be prepared to operate the alarum instantaneously upon
any emergency.
To prevent the alarm from being used wantonly, and to cause the particular
compartment or identical seat from which it may be operated to be indicated;
I form a bight or loop in each pull, out of the reach of the passengers but
accessible for inspection by the guards in charge of the train. Before the
pull can operate the alarm this bight or loop or smaller cord (which is attached
to the pull) has to be broken or separated from its connection, such breakage
or disconnection at once indicating by inspection the particular pull ¸used.

page_text: A second use of these smaller cords, which require a little force to be applied
to release the main pull, is to prevent the alarum from being operated unin-
tentionally or accidentally.
The periphery of the friction pulley is formed with a number of cavities
therein, which cavities, when necessary, may be fitted with detonating matter
so as to produce a succession of loud reports when revolving in contact with
the carriage wheel.
A third modification of this apparatus, keeping the same main parts,
consists of a rotating sounding drum with a ratched or toothed periphery
rotating against a spring pawl fixed to a sounding pedestal or box. This
spring pawl may be formed of a single blade or may be threefold, that is to
say,
with one longer and centre and two shorter and side blades. The object
of the latter mode of forming the spring pawl, sounding tongue, or clapper is
to cause it to give out an alarm sound of itself when the centre blade is caused
to vibrate between the outer ones. The revolving cross arms, revolving
sounding drum, and blade operating ratchet or wheel are worked by the
friction pulley a and shaft c by the forward motion of the carriage in either
direction. The standard g may be mounted upon a hollow box open at one
end or with perforated sides, and fixed to the carriage roof at h, h, when the
sound produced by attaching the standard g is deemed to be insufficient. I
also propose to use a sounding box with a vibrating spring tongue or clapper
on the top or other part thereof, the said tongue or clapper being operated by
the revolutions of the arms d, d, lifting or moving the same when put into
motion by the pulls, friction pulley, and train wheel, as before deseribed.
From the position in which the apparatus is placed on the roof of
the carriage it is beyond the reach of any one intending to prevent its
action by tampering with it. (I may here observe that by uncoupling or
cutting the continuous cord alarums their operation is instantly stopped.)
The attention of the guards and engine driver is attracted simultaneously by
the apparatus now proposed, and a loud and incessant noise being the medium,
it admits of no means of intercepting it. The immediate effect of this noise
upon a person committing an assault would be terror, for he could not con-
tinue his wicked practice while the alarm was sounding above him, and thereby
render his instant detection certain.
Without restricting myself to the precise forms and dispositions of the parts
of the apparatus shewn and described, I claim,―
1st, the taking of the motion from the carriage wheel, axle, or rail by a
moveable friction wheel, brought into contact by releasing a draw bolt by

page_text: means of a looped or bighted pull cord in connection therewith, the said pull
having a terminal arm, ring, or loop fitted thereto at each seat of the
carriage.
2ndly, the rotating pellets and sounding plate, as shewn upon the Drawing,
and the sounding boxes, drums, ratchets, and vanes fitted and operated as
herein explained.
In witness whereof, I, the said John Clark, have hereunto set my hand
and seal, this Fourteenth day of January, in the year of our Lord
One thousand eight hundred and sixty-five.
JNO. CLARK. (L.S.)