IMPROVE- MENTS IN ELECTRO-MAGNETIC CLOCKS AND OTHER TIMEKEEPERS
Year: 1865

page_text: LETTERS PATENT to Richard Archibald Brooman, of 166, Fleet Street,
in the City of London, Patent Agent, for the Invention of "IMPROVE-
MENTS IN ELECTRO-MAGNETIC CLOCKS AND OTHER TIMEKEEPERS."—A com-
munication from abroad by Jean Theodore Scholte, of Paris, France.
Sealed the 27th November 1865, and dated the 2nd June 1865.
PROVISIONAL SPECIFICATION left by the said Richard Archibald Brooman
at the Office of the Commissioners of Patents, with his Petition, on the
2nd June 1865.
I, RICHARD ARCHIBALD BROQMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN ELECTRO-MAGNETIC CLOCKS AND OTHER TIMEKEEPERS," to be
as follows::
This Invention consists in the employment of electricity to set timekeepers
going directly by electro-magnetism, in such manner that the electric current
only exerts its action when the pendulum is reduced to a fixed minimum of
oscillation, and that a new impulse by electro-magnetic power only takes
place when the force of the preceding impulsion is spent, it is therefore the
clock itself which regulates the supply of electricity after a time depending.
upon the power of the battery with a constant current or not.
Lfit.at the bottom of a seconds or half seconds pendulum an armature, the
direction of which is perpendicular to the plane of oscillation; under the
armature is an electro-magnet capable of attracting the armature when the

page_text: jendulum returns from its greatest amplitude to the left or to the right to the
position of repose. This impulsion of the electro-magnet does not, however,
take place after every oscillation, but only when the amplitude diminishes to
a certain, degree. The current, which in this case passes though the electro-
magnet, ceases when it has acted upon the armature in such manner as to
impart a new impulsion to the armature. If then the battery is of great
power, the impulsion will be powerful, and consequently the amplitudes of
oscillation will be relatively great, therefore a certain number of oscillations
is necessary in order that the pendulum, in consequence of the friction and of
the resistance of the wheelwork, may be reduced to the minimum of ampli-
tude, which causes a fresh impulsion from the electro-magnet. If on the
contrary the battery is weak, the impulsions will be weak, but more rapid,
because after each impulse the pendulum will only exceed very slightly
the minimum of amplitude. To obtain the impulse at the moment of the
minimum of amplitude, I arrange at the extremity of the pendulum the
mechanism shewn in the accompanying Drawing."
.I .
A, B, and C are three brass columns; A is insulated, and A and C carry
screws a and b to regulate their height; D is a lever resting upon the
column C; this lever free to pivot upon the column B is furnished at c with a
notched steel block; F is a second lever hinged at d to the lever D, and
drawn downwards by the spiral spring E. To prevent this second lever when
at rest, touching the column A, but to permit it to approach as nearly as.
possible, I use a screw G, which passes through the levers D and F. The
pendulum P carries a readily movable steel pin g, which at each oscillation of
the pendulum slides upon the block c. If the amplitudes of oscillation have
diminished so far that the pin is prevented from sliding when the pendulum
beats to the left, then on its return the lever D will be pressed down for a
noment; and the lever F will touch the column A; contact is then established,'
which allows the current to circulate in the electro-magnet; for the current:
then starts from the battery through the wire i, the spiral spring E, 'the
lever F, the column A, and returns through the electro-magnet and the
wire m. The mechanism. whereby these independent oscillations. of the
pendulum are communicated to the clockwork is as follows:-At the upper
part of the pendulum there is a double arm lever k, the arm at every
oscillation to the left is displaced once from its position to the left, and the
arm m¹ rises; this arm carries a springin, which acts upon the wheel o, and
causes it to advance one tooth each time that the arm m³ rises and falls.. The
wheel o has 80 teeth for a half seconds pendulum, and completes two re-
volutions in a minute. The arm m' is held up at n to prevent it falling too:

page_text: low. The wheel o carries an endless screw p in a horizontal position parallel
with the plane of oscillation of the pendulum. This screw gears into a wheel
D' with 120 teeth, and this wheel consequently completes one revolution in an
hour. This wheel carries the minute hand, and to it the hour hand is
connected in the ordinary manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Archibald Brooman in the Great Seal Patent Office
on the 2nd December 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of London, Patent
Agent, send greeting.
WHEREAS Her most 'Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of June, in the year of our Lord One
thousand eight hundred and sixty-five, in the twenty-eighth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said Richard Archibald Brooman, Her special licence that the said
'
executors, administrators, and assigns, or such other's
as I, the said Richard Archibald Brooman, 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 law-
fully might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN ELECTRO-MAGNETIC CLOCKS AND OTHER TIMEKEEPERS,"
(communicated to me from abroad by Jean Theodore Scholte, of Paris, France,)
upon the condition (amongst others) that I, the said Richard Archibald Brooman,
my executors or administrators, by an instrument in writing under my,
their, or one of their hands and seals, should particularly describe and, ascer-
tain 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.
"
or
NOW KNOW YE, that I, 'the said Richard Archibald Brooman, 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
following statement thereof, reference being had to the Drawings hereunto
annexed, that is to say:-

page_text: This Invention consists in the employment of electricity to set timekeepers
going directly by electro-magnetism, in such manner that the electric current
only exerts its action when the pendulum is reduced to a fixed minimum of
oscillation, and that a new impulse by electro-magnetic power only takes
place when the force if the preceding impulsion is spent, it is therefore the
clock itself which regulates the supply of electricity, after a time depending
upon the power of the battery with a constant current or not.
I fit at the bottom of a seconds or half seconds pendulum an armature, the
direction of which is perpendicular to the plane of oscillation; under the
armature is an electro-magnet capable of attracting the armature when the
pendulum returns from its greatest amplitude to the left or to the right to the
position of repose. This impulsion of the electro-magnet does not, however,
take place after every oscillation, but only when the amplitude 'diminishes to
a certain degree. The current, which in this case passes through the electro-
magnet, ceases when it has acted upon the armature in such manner as to
impart a new impulsion to the armature. If then the battery is of great
power the impulsion will be powerful, and consequently the amplitudes of
oscillation will be relatively great, therefore à certain number of oscillation's is
necessary in order that the pendulum, in consequence of the friction and of
'the resistance of the wheelwork, may be reduced to the minimum of ampli-
'tude, which causes a fresh impulsion from "the electro-magnet. If on the
contrary the battery is weak, the impulsions will be weak, but more rapid,
because after each impulsé thé pendulum will only exceed very slightly 'the
minimum of amplitude. To obtain the impulse at 'the 'moment of the
minimum of amplitude, I arrange at the extremity of the pendulum the
mechanism shewn at Figure 1 of the accompanying Drawings.
A, B, and C, are three brass columns; A is insulated, and A 'and 'C 'carry
screws a and b to regulate their height; D is a lever 'resting 'upon the
column C; this lever, free to pivot upon the column B, is 'furnished at c with
a notched steel block; F is a second lever hinged at d to the lever D, 'and
drawn downwards by the spiral spring E. To prevent this 'second 'lever 'when
at rest touching the column A, but to permit it to approach as nearly as
possible, I use a screw G, which passes through the levers D and F. The
pendulum P carries a readily movable steel pin g, which at each oscillation of
the pendulum slides upon the block c. If the amplitudes of oscillation have
diminished so far that the pin is prevented 'from sliding when the pendulum
beats to the left, then on its return the lever D will be pressed down for a
moment, and the lever F will touch the column A, contact is then established,
which allows the current to circulate in the electro-magnet; for the current

page_text: then starts from the battery through the wire i, the spiral spring E, the
lever F, the column A, and returns through the electro-magnets and the
wire. m. The mechanism whereby these independent oscillations of the
pendulum are communicated to the clockwork is as follows:-At the upper
part of the pendulum there is a double arm lever k, the arm at every
oscillation to the left is displaced once from its position to the left, and the
arm m' rises; this arm carries a spring n, which acts upon the wheel o, and
causes it to advance one tooth each time that the arm m' rises and falls. The
wheel o has thirty teeth for a half-seconds pendulum, and completes two revo-
Jutions in a minute. The arm m¹ is held up at n to prevent it falling too
low. The wheel o carries an endless screw p in a horizontal position parallel
with the plane of oscillation of the pendulum. This screw gears into a wheel
D' with 120 teeth, and this wheel consequently completes one revolution in
an hour. This wheel carries the minute hand, and to it the hour hand is
connected in the ordinary manner.
Instead of the arrangement of contacts above described more simple
arrangements, such, for example, as that represented in Figure 2, may be
adopted for common timekeepers.
The mechanism for closing the current and the electro-magnets together or
separately may be fitted in any convenient position, & at a greater or less
height in relation to the pendulum.
And having now described the nature of the said Invention, and in what
'manner the same is to be performed, I declare that I claim constructing
electro-magnetic clocks and other timekeepers substantially as herein-before
described and represented in the accompanying Drawings.
In witness whereof, I, the said Richard Archibald Brooman, have here-
unto set my hand and seal, this Thirtieth day of November, One
thousand eight hundred and sixty-five.