AN IMPROVED WATCHMAN'S ELECTRIC TELL-TALE AND FIRE ALARM
Year: 1877

page_text: LETTERS PATENT to William John Hancock and Stephen Mitchell Yeates, of
Dublin, in tho County of Dublin, Ireland, for the Invention of "AN IMPROVED
WATCHMAN'S ELECTRIC TELL-TALE AND FIRE ALARM."
Sealed the 20th October 1877, and dated the 24th April 1877.
PROVISIONAL SPECIFICATION left by the said William John Hancock and
Stephen Mitchell Yeates at the Office of the Commissioners of Patents on the
24th April 1877.
WILLIAM JOHN HANCOCK and STEPHEN MITCHELL YEATES, of Dublin, in the
County of Dublin, Ireland. "AN IMPROVED WATCHMAN'S ELECTRIC TELL-TALE
AND FIRE ALARM."
Our said Invention consists, first, in the application of electricity to tell-tale
clocks for mills, factories, warehouses, stores, banks, jails, workhouses, hospitals,
asylums, steam and sailing vessels, by means of which an alarm is given if contact
is not renewed at the proper time; and secondly, of a contrivance by which an
alarm can be given from any number of stations or compartments, and an improved
indicator that shews which compartment the signal is sent from.
The first part of our Invention is effected by fixing a pin, wheel, or cam on the
minute arbor of any ordinary clock; this lifts an arm carrying two contact springs S
and S¹ on to a stop fixed in the armature of an electro-magnet, which holds said
arm in position until contact is made by the person in charge; if left in this
position longer than the proper time, the cam in revolving makes contact with the
spring S, and shews that the person in charge has not renewed the contact or has
been absent from his post.
If, instead of making contact at the proper intervals, permanent contact is made
by the watchman, the electro-magnet will not hold the arm and springs in position,
and the cam in revolving comes into contact with spring S³, and thereby gives an
alarm by ringing a bell or other signal.

page_text: When a number of stations are to be signalled from, a small shaft is fitted with a
corresponding number of cams and contact springs, with an indicator or number
fixed in electrical circuit with each.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William John Hancock and Stephen Mitchell Yeates in the Great
Seal Patent Office on the 24th October 1877.
WILLIAM JOHN HANCOCK and STEPHEN MITCHELL YEATES, of Dublin, in the
County of Dublin, Ireland. "AN IMPROVED WATCHMAN'S ELECTRIC TELL-TALE
AND FIRE ALARM."
Our said Invention consists, first, in the application of electricity to tell-tale
clocks for mills, factories, warehouses, stores, banks, jails, workhouses, hospitals,
asylums, steam and sailing vessels, by means of which an alarm is given if contact
is not renewed at the proper time by the watchman in charge; and secondly, of a
contrivance by which an alarm can be given from any number of stations or com-
partments, and an improved indicator that shows which compartment the signal is
sent from.
The first part of our Invention is effected by fixing a pin, wheel, or cam on the
minute arbour of any ordinary clock; this lifts an arm carrying two contact
springs S and S' on to a stop fixed in the armature of an electro-magnet, which
holds said arm in position until contact is made by the person in charge; if left in
this position longer than the proper time, the cam in revolving makes contact
with the spring S, and shows that the person in charge has not renewed the contact
or has been absent from his post.
If, instead of making contact at the proper intervals, permanent contact is made
by the watchman, the electro-magnet will not hold the arm and springs in position,
and the cam in revolving comes into contact with the spring S', and thereby gives
an alarm by ringing a bell or other signal.
When a number of stations are to be signalled from, a small shaft is fitted with a
corresponding number of cams and contact springs, with an indicator or number
fixed in electrical circuit with each.
In order that our said Invention may be more readily understood, we proceed to
describe the accompanying Drawings.
Fig. 1 shows the application of our improved electric tell-tale and fire alarm to
the face of an ordinary clock, as illustrating the first part of our Invention.
Fig. 2 shows the complete apparatus detached, and Fig. 3 represents the apparatus
illustrating the second part of our Invention.
It will be obvious that the minute hand in moving round the dial (Fig. 1) will
carry the cams of the arbour in contact with the insulated piece of ivory attached
to the extremity of the arm S¹ which causes the arm A to slip on to the ivory
stop B attached to the armature C; if held in this position the cam in revolving
strikes the spring S, and shows that contact has not been made at the proper time.
Should permanent contact be made by the watchman in charge instead of contact
at the proper intervals, the electro-magnet will not hold the arm and springs in
position, and the cam will then come in contact with the arm S¹, and thereby give
an alarm by ringing a bell or other signal.
The second portion of our Invention is illustrated in Fig. 3, the action of which
may be described thus:-t, t, are cams which rotate with the arbour of an ordinary
clock, and act on the arms S, S¹, in the manner described in reference to Figs. 1
and 2. On this arbor is a tangent screw or other contrivance by which the drum D
is caused to revolve. Round the periphery of this drum a slip of paper is secured
which receives a mark from the pencils p, p, carried by the vertical arms E, F, each

page_text: time contact is made by the person in charge. Two pencils only are shown in the
Drawing, but it will be readily understood that any number may be employed
corresponding to the number of apartments to be signalled from.
Instead of pencils steel points may be used to puncture the paper, thus making
an indelible record.
Having thus described the nature of our said Invention, and the manner in
which the same may be carried into effect, we would have it understood that what
we consider to be novel and useful, and therefore claim as the Invention secured to
us by the herein-before in part recited Letters Patent is,―
First. The application of electricity to tell-tale clocks in the manner substantially
as herein described and set forth.
Second. The employment of a contrivance or apparatus operated by electricity,
substantially as described in reference to our accompanying Drawings, in the
manner and for the purpose specified.
In witness whereof, we, the said William John Hancock and Stephen Mitchell
Yeates, have unto this our Specification set our hands and seals, this
Twenty-third day of October, in the year of our Lord One thousand eight
hundred and seventy-seven.
20
Witness,
J. A. FAHIE,
2, Nassau St.,
Dublin.
WILLIAM JOHN HANCOCK.
W. J. HANCOCK.
(L.S.)
STEPHEN MITCHELL YEATES. (LS.)