IM- PROVEMENTS IN THE MEANS OF ACTUATING ELECTRIC DIALS OR CLOCKS
Year: 1864

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County,
of Middlesex, Engineer and Patent Agent, for the Invention of "IM-
PROVEMENTS IN THE MEANS OF ACTUATING ELECTRIC DIALS OR CLOCKS."-A
communication from abroad by Anatole Jean Baptiste Lesieur and
Pierre Désiré Prud'-homme, Mathematical Instrument Maker, both of
29. Boulevart St. Martin. Paris.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 27th'
September 1864.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,:
Engineer and Patent Agent, do hereby declare the nature of the said..Inven-
tion for "IMPROVEMENTS IN THE MEANS OF ACTUATING ELECTRIC. DIALS OR CLOCKS,"
to be as follows:-,
.Up.to the present time the mechanism of electric clocks has consisted: of an:
electro-magnet, which becomes active on the passage of the current :being so,
magnetised for the special object of acting on an armature in proximity.to.its:
poles; this armature communicates motion direct .to the wheel, mechanism.
and hands, whatever may. otherwise be the arrangement of the mechanism...
This method possesses serious disadvantages,. the result of which is to cause
inaccuracies in the times indicated, the principal causes of which are that, 1st,

page_text: when the electro-magnet becomes active its armature must first overcome
the inertia due to the material; next, that of the tension of the antagonistic
spring; and, lastly, the resistance due to the wheelwork. Now, as it is just
at this moment that the armature is at the greatest distance from the poles
of the electric magnet, it results 'that the attractive force is found to be of
minimum effect, and if the pile becomes weakened either by a reduction in
the temperature or from other cause, the magnetism, although actually taking
place, is not of sufficient power to overcome all these resistances simul-
taneously, hence it inevitably results that variations occur in the time
indications. 2ndly, to obviate this, piles of excessive power have been
adopted, which is a disadvantage of another character, as the latent mag-
netism prevents the antagonistic spring from bringing back the armature to
position, thus rendering the clock still imperfect. It is also well known that
notwithstanding the precautions taken for ensuring the necessary contact for
completing the voltaic circuit, it often happens that the current does not pass,
on which occasions the wheel mechanism will not act, so causing the clock to
lose time.
I will now proceed to describe an arrangement for obtaining synchronism
in the movements of all the clocks in a town or otherwise.
In the annexed Drawing; A, B, represents a pendulumi of sufficient length
to produce a complete oscillation' in half a second; C, soft iron armature;
fixed at lower end of pendulum B; D, electro-magnet placed at a certain
distance from armature C, and so that its upper surface will permit of the
pendulum. oscillating freely without striking it; E, lever fixed to the pen-
dulum at F, having a projecting tooth rotating the ratchet wheel G the
extent of a tooth for every two oscillations of the pendulum; H, fixed steel
point on which rests the end of lever E, and having a notch at its end to
allow of the lever being depressed in a given time in order to advance the
ratchet G. one tooth only, said ratchet communicating motion to the wheel
mechanism. The parts communicating this motion being required to close
the circuit every second, the electro-magnet.. D. will consequently become
active at each second for a certain length of time, and as the pendulum A, B,
is of such length as to produce two oscillations per second, it results that it
becomes attracted by the temporary magnetism of the electro-magnet every
time its armature passes in proximity thereto.. The pendulum first produces
slight oscillations, the extent of which are very rapidly increased, and in a
few moments it oscillates precisely as if it was regulated by an ordinary.clock-
work movement; the lever E then acts on a tooth or ratchet: G, & so
works the hands.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
27th March 1865.
:
:
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and;
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her. Letters
Patent, bearing date the Twenty-seventh day of September, 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 William Clark, Her special licence that. I, the said.
William Clark, my executors, administrators, and assigns, or such others,
as I, the said William 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 "IMPROVEMENTS IN THE MEANS OF ACTUATING ELECTRIC DIALS OR CLOCKS,"
a com to me from abroad by Anatole Jean Baptiste Lesieur and Pierre
Désiré Prud-homme, Mathematical Instrument Maker, both of 29, Boulevart..
St. Martin, Paris, upon the condition (amongst others) that I, the said
William 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.
NOW KNOW YE, that I,' the said William 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 follow-
ing statement, reference being had to the Sheet of Drawings hereunto
annexed, and to the letters and figures marked thereon (that is to say):-
. Up to the present time the mechanism of electric clocks has consisted of
an electro-magnet which becomes active on the passage of the current, being.

page_text: so magnetised for the special object of acting on an armature in proximity to its
poles; this armature communicates motion direct to the wheel mechanism and
hands, whatever may otherwise be the arrangement of the mechanism. This
method possesses serious disadvantages, the result of which is to cause inac-
curacies in the times indicated, the principal causes of which are that, 1st,
when the electro-magnet becomes active its armature must first overcome the
inertia due to the material; next, that of the tension of the antagonistic
spring; and, lastly, the resistance due to the wheelwork. Now, as it just
at this moment that the armature is at the greater distance from the poles of
the electro-magnet, it results that the attractive force is found to be of
minimum effect, and if the pile becomes weakened either by a reduction' in
the temperature or from other cause, the magnetism, although actually taking
place, is not of sufficient power to overcome all these resistances simul-
taneously, hence it inevitably results' that variations occur in the-time indi-
cations. 2ndly, to obviate this, piles of too great power have been adopted,
which is a disadvantage of another character, as the latent magnetism pre-
vents the antagonistic spring from bringing back the armature to position,
thus rendering the clock still imperfect. It is also well known that not-
withstanding the precautions taken for ensuring the contact necessary for
completing the voltaic circuit, it often happens that the current will not pass,
on which occasions the wheel méchanism will not act, so causing the clock to
lose'time.
"
.
With a view to obviate these disadvantages and ensure regularity in the
time indications, I will now proceed to describe an arrangement for obtaining
synchronism in the movements of all the clocks in a town or otherwise.
In the annexed Drawing, A, B, represents a pendulum of sufficient length
to produce a complete 'oscillation in half a second; C, soft iron armature
fixed at lower end of pendulum B'; D, electro-magnet placed at a suitable
distance from armature C, and so that its upper surface will permit of the
pendulum oscillating freely without striking it; E, lever fixed to 'the pendulum
at F, and carrying a projecting tooth rotating the ratchet wheel G the
extent of a tooth for every double oscillation of the pendulum; H, fixed steel
point on which rests the end of lever E, and having a notch at its end to
allow of the lever being depressed in a given time in order to advance the
rátchet G one tooth only, said ratchet 'communicating motion to the wheel
mechanism. The parts communicating this motion being required to close
the circuit every second, 'the electro-magnet D will consequently become active
at each second for a certain length of time, and as the pendulum A, B, is of
such length as to produce two oscillations per second, it results that it becomes

page_text: attracted by the temporary magnetism of the electro-magnet every time its
armature passes in proximity thereto. The pendulum first produces slight
oscillations, the extent of which are very rapidly increased, and in a few
movements it oscillates precisely as if it was regulated by an ordinary clock-
work movement; the lever E then acts on a. tooth of ratchet G, and so works
the hands.
This improved means of actuating electric timekeepers is also applicable to
a balance-wheel arrangement furnished with a spiral spring.
Having described the nature of this Invention, and the manner of per-
forming the same, I declare that what I claim as the Invention to be protected
by the herein-before in part recited Letters Patent is, the use of a pendulum
governed by magnetism for communicating motion to the mechanism of all
kinds of electric dials or clocks, as herein-before described.
In witness whereof; I, the said William Clark, have hereunto set my.
hand and seal, this Twenty-fifth day of March, in the year of our Lord
One thousand eight hundred and sixty-five.
Witness,
JAMES DAISH,
53, Chancery Lane,
London.
W. CLARK. (L.S.)