NEW OR IMPROVED APPARATUS FOR SYNCHRONISING CLOCKS
Year: 1877

page_text: LETTERS PATENT to James Brockie, of Canonbury, in the County of
Middlesex, for the Invention of "NEW OR IMPROVED APPARATUS FOR
SYNCHRONISING CLOCKS."
Sealed the 19th February 1878, and dated the 17th December 1877.
PROVISIONAL SPECIFICATION left by the said James Brockie at the Office
of the Commissioners of Patents on the 17th December 1877.
JAMES BROCKIE, of Canonbury, in the County of Middlesex.
IMPROVED APPARATUS FOR SYNCHRONISING CLOCKS."
"NEW OR
This Invention has reference to a more simple and efficient arrangement of
mechanism than has heretofore been used for moving the minute hands of clocks
(or other equivalent lever fixed on its spindle), so as to set them to zero or true
time, and so synchronise the clocks in a more simple manner than hitherto at each
hour or other set periods by the action of an ordinary cowl or other electro-magnet
to each clock, and improved arrangement of mechanism actuated by electric wires
reversing the current by an observatory or other exactly-timed normal or standard
clock.
And the nature and novelty of the Invention consist essentially in the employ-
ment of a bar, preferably S shaped, moving on a centre or spindle acting upon the
minute or other hands of clocks, so as to bring the hands to a given point on the
dial at a given time. The object of the Invention being to enable any number of
clocks to be electrically synchronised or corrected by a standard timekeeper at
stated intervals.
The method of carrying out the Invention is substantially as follows:-The clocks
intended to be synchronised or corrected are connected electrically with a reliable
standard clock or other time indicator in a manner well understood and known by
electricians; and an electro-magnet is fixed to each clock to supply the motive-
power for working the apparatus. The duty of this magnet is to cause the spindle
of the bar or duplex S cam to revolve one quarter of a revolution, or nearly so,
which spindle is made to project through a small hole made in the dial of the clock
Prine Rd 1

page_text: to be corrected, preferably behind the minute hand, at zero or 12 o'clock. This
said quarter turning of the said spindle is obtained by means of a lever attached to
the armature of the magnet; this lever has a slot at its extremity, into which the
pin of a small crank works, being keyed or fixed to the inner end of the spindle of
the bar or S cam to be rotated.
It will be seen that on completing the circuit or passing a current of electricity
round the magnet the keeper will be attracted to it, and the gearing above described
will cause the spindle to revolve; the extent of said revolution will of course
depend upon the relative lengths of the lever attached to the armature and the
crank, also the travel of the armature, but these are so arranged that the spindle
and its acting bar or S cam will make a quarter turn, or nearly so, upon the arma-
ture being attracted to the magnet; when the current ceases, the armature retires
from the magnet by means of a balance weight, spring, or their equivalent, which
would bring the spindle to its original or normal position.
The influencing or moving and correcting of the minute hand of the clock by
this improved arm or S cam on the outer end of the spindle is effected as follows:--
Suppose the clock is required to be corrected at every hour, the apparatus is so
fixed that the said spindle carrying the rocking S shaped bar or cam projects
through the dial at a point in perpendicular line with the zero point, as a rule near
the end of the clock-hand radius, the exact perpendicular position being determined
by the particular construction of the clock, two pins being fixed on the inner or dial
side of the hand to be corrected of such length that they clear the dial, the exact
position of these said pins being such that when the clock hand points to zero the pins
will be equidistant from and in perpendicular line with the said projecting spindle
which carries the S shaped bar or cam; the bar must be between the clock hand and
the dial, and in such horizontal position that the pins and hand clear it as they pass
near the zero point The mechanism being thus arranged, it will be seen that
should the clock hand be, say, ono minute fist or slow of the zero point at the
instant it is to be synchronised it will be adjusted by causing the S shaped bar or
can to assume a perpendicular from a horizontal position, so that the said bar
will catch one or other of the said pins in the hand and push it exactly to the
zero point.
The extent of correcting power of this apparatus will of course depend upon the
length of the S shaped bar and the distance of the pins apart.
It will be seen that by attaching an apparatus such as above described to a clock
or clocks, and connecting them electrically with a standard timekeeper or indicator,
when this said standard clock transmits a current of electricity exactly at every
hour the magnet in the other clocks, or those to by synchronised, will cause the S
shaped bar to assume a perpendicular position, and thus correct the hands in the
manner described if they should be either fast or slow of the zero point.
Instead of the S shaped bar a straight bar might be employed, but the S shape
is preferred, as it works more satisfactorily by giving a wider range of correcting
power.
By another arrangement, in order to make the rocking bar or cam act on the
clock hand itself if required, and not on pins or blocks fixed upon it, a pin is
placed on each end of the bar of such length that when the bar is in its normal or
horizontal position the hand just clears the pins; and in order that they may still
control the hand, the spindle, on the arrival of the current, is moved slightly
forward as well as turned round or oscillated, which forward movement brings the
pins and bar within ange of the hand on opposite sides, this forward movement
being obtained by means of a radius bar fixed on the spindle and working in a slot
cut at an angle, or an analogous device, so that when the bar is oscillated, as before
described, by the magnet on completing the electric circuit, it would bring the hand
to zero, whether it had gained or lost time, and instantly assume its normal
position with the pins back behind the hand as soon as the circuit is broken by
the standard electric clock; and instead of giving this forward motion of the aim
or bar and its pins, a thin plate of steel or other equivalent could be rivetted to the

page_text: back of the hand, with a slot in the centre to clear the pins when the arm is in its
normal horizontal position, and yet allow the pins to move and set the hand to zero
when actuated by the electro-magnet and standard clock, all otherwise as herein-
before described.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Brockie in the Great Seal Patent Office on the 15th June
1878.
JAMES BROCKIE, of Canonbury, in the County of Middlesex.
IMPROVED APPARATUS FOR SYNCHRONISING CLOCKS."
"NEW OR
My said Invention has reference to a more simple and efficient arrangement of
mechanism than has hitherto been used for moving the minute hands of clocks
(or other equivalent lever fixed on its spindle), so as to set them to zero, or true
time, and so synchronise the clocks in a more simple manner than hitherto, at each
hour or other set period by the action of an ordinary coil or other electro-magnet to
each clock, and improved arrangement of mechanism actuated by electric wires
reversing or cutting off the current by an observatory or other exactly-timed normal
or standard clock.
And the nature and novelty of the Invention consist essentially in the employ-
ment of a bar A, Figure 1, preferably S shaped, moving on a centre or spindle
B, acting on the minute or other hands of clocks, so as to bring the hands
to a given point on the dial at a given time. The object of the Invention being to
enable any number of clocks to be electrically synchronised or corrected by a
standard timekeeper at stated intervals.
The method of carrying out the Invention is substantially as follows:-The
clocks intended to be synchronised or corrected are connected electrically with n
reliable standard clock or other time indicator in a manner well known and
understood by electricians, and an electro-magnet is fixed to each clock to supply
the motive power for working the apparatus. The duty of this magnet is to cause
the spindle B, Figure 1, of the bar or duplex cam A to revolve one quarter of a
revolution, or nearly so, which spindle is made to project through a small hole in
the dial of the clock to be corrected, preferably behind the minute hand C, at zero
or 12 o'clock, as shown in Figure 1. This said quarter or partial turning of the
said spindle is obtained by means of a lever D, Figure 2, attached to the armature E
of the electro-magnet F, F, this lever has a slot G at its extremity into which the
pin of a small crank H works, this crank is keyed or fixed to the inner end of the
spindle B, upon which the S cam to be rotated is also keyed or fixed as shown in
Figure 3.
It will be seen that on completing the circuit or passing a current of electricity
round the magnet F, the keeper E will be attracted to it, and the gearing above
described will cause the spindle to revolve; the extent of said revolution will of

page_text: course depend upon the relative lengths of the lever D and crank H, also the travel
of the armature, but these are so arranged that the spindle B and its acting bar or
S shaped cam A will make a quarter turn or nearly so; when the current ceases
the armature retires from the magnet by means of a balance weight, spring, or
other equivalent, which would bring the spindle with its S cam to its original or
normal position; a convenient balance weight is obtained by making the slotted end
of the lever D rather massive as shown in the Drawing, so as to outweigh slightly
the armature E.
The influencing or moving, and correcting of the minute hand of the clock by
this improved arm or S cam on the outer end of the spindle B is effected as follows:-
As before stated, this spindle carrying the cam projects through the dial at or near
the centre of the figure XII., as shown in Figure 1. Two pins P, P, Figures
and 3, are fixed on the inner or dial side of the hand to be corrected, of such length
as to clear the dial M, Figure 3. The exact position of these said pins being such
that when the clock hand points to zero they shall be equidistant from and in
perpendicular line with the said projecting spindle B. The bar or cam A must be
between the clock hand and dial, and in such horizontal position as shown in
Figure 1, that the pins P, P, and hand clear it as they approach and depart from
the zero point. The mechanism being thus arranged it will be seen that should the
clock hand be a little fast or slow (say, about one minute), of the zero point at the
instant the current is sent, the hand will be adjusted by the S cam assuming
a perpendicular position, as the cam will catch one or other of the pins in the hand,
and push it either back or forward as required exactly to the zero point.
The extent of correcting power of this apparatus will depend upon the length of
the S shaped cam and the distance of the pins apart.
It will be seen that by attaching an apparatus such as above described to a clock
or clocks, and connecting them electrically with a standard timekeeper, when the
said standard timekeeper transmits a current of electricity exactly at every hour,
the magnets in the clock to be synchronised will cause the S cams to assume a
perpendicular position, and thus correct the hands in the manner described if they
should be fast or slow of the zero point to the extent of about one minute. When
the current is cut off (or reversed if polarised armatures are used) the S cams will
fall back again to their normal position, and allow the hands to go on.
Instead of the S shaped bar or cam a straight one could be used, but the S shape
is preferred as a rule, as it works more satisfactorily and gives a wider range of
correcting power.
A modification of this plan is adopted by me when the hand itself is required
to be acted upon directly, and not upon pins fixed into it. A pin in this case is
placed on each end of the rocking bar B, of such length that when the bar is in its
normal or horizontal position the clock hand just clears then; and in order that
they may still control the hand the spindle B on the arrival of the current is moved
slightly forward, as well as turned partially round, which forward movement 18
obtained by means of a radius pin or bar fixed on the spindle at the crank end and
working in a slot cut at an angle to the said spindle or an analogous device, so
that when the bar is oscillated, as before described, by the magnet by completing
the electric circuit it would bring the hand to zero, whether it had gained or lost
time, and instantly assume its normal position with the pins back behind and clear
of the hand as soon as the circuit is broken or reversed by the standard clock; and
instead of giving this forward motion to the arm or bar with its said pins a thin
plate of metal or other equivalent could be fixed to the back of the hand, with a
slot or space in the centre to enable the hand to clear the projecting pins when the
arm is in its normal or horizontal position, and yet allow the pins to set and move
the hand to zero by coming in contact with the said plate or plates of metal fixed
to the hand when the magnet causes the arm B to assume a perpendicular position,
all otherwise as herein-before described.
In applying this Invention to clocks having heavy movements, such as turret
clocks. I prefer to use the power of a falling weight to work the S shaped cam,

page_text: instead of a current of electricity, the duty devolving upon the current in such
cases being merely to release the said falling weight at the proper time during the
intervals of correction, which may be hourly or only daily; the weight is gradually
raised by the clockwork in order that it may again be ready to descend when
released. Instead of the falling weight acting thus directly upon the S cam a
wheel, having, say, four projecting arms on its outer circumference and driven by a
separate weight or other motor could be made to act upon the cam, the magnet in
this case allowing the said wheel to make one quarter of a revolution only for each
current sent, all in manner following:-Upon any convenient spindle or arbor of
the clockwork I place an arm or lever E, Figure 4, having two pins F, F, near its
extremity, corresponding to the pins in the clock hands before described. Parallel
to and in close proximity to this said arm and between the said pins I poise
an S shaped cam A in such position that the pins F, F, and lever E clear it in
passing, but upon the cam assuming a perpendicular position the pins F, F, will
come within its range and be moved by it should the lever E be out of the true
perpendicular, as previously described. Now in order to obtain the requisite
movement of the cam I key a lever B, B, on the same spindle upon which the said
cam is also keyed; this double lever has a balance weight W at its extremity to
keep it in a horizontal position and against the stop S. Parallel and very close to
this said lover I place a longer lever C, C, with a heavy weight at its extremity; a
stop T limits the fall of this said lever. A sliding pin D is placed in this lever C
so that when the lever is raised this sliding pin will be pressed back by the side of
the lever B as it passes in an upward direction, it being wedge shaped for this
purpose, as shown in Figure 5, and when the lever C gets above the lever B the
pin shoots out again, and thus overlaps the lever B. A catch now secures the
weighted lever C, and it is this catch which the current from the standard clock
releases. It will be seen that upon the catch being drawn back by the current the
weighted lever C is free to fall, and in its downward course it carries the lever B
with it by means of the projecting pin D until this pin slips past the end of the
lever B owing to the difference of radius of the two levers B and C; when the
lever B thus escapes the pin D the balance weight W tilts it up again against
the stop S, carrying the cam with it to its normal position. Should the arm E
have been slightly out of the perpendicular when the weighted arm C began to
descend, the cam A. would have adjusted it and then fallen back again, as shown in
Figure 4, to allow the arm to go on again, thus the clock would be corrected at
that particular time.
As before stated, instead of using a falling weight to act thus directly upon the
cam spindle by the lever B a wheel, shown in dotted lines at N in Figure 4 could
be used. The current in this case is made to let the wheel make one quarter of a
revolution, and in so doing one of the arms of the said wheel comes in contact with
the lever B and pushes it downwards until it slips past it in an analogous manner
to the weighted lever C before described. The advantage in thus using a separate
motor to drive the correcting cam is that no additional work is given to the clock,
as in the method immediately before described.
The details of these various modes by which motion could be imparted to the
Scam or bar might be modified to a great extent, according to the particular con-
struction of clock or other circumstances, but I find the methods described to be
simple and to work well.
Having now described the nature of my said Invention and how the same is to
be performed, I hereby claim,-
First. The general arrangement and construction of apparatus, substantially as
herein described, for the purpose of synchronising clocks or other registers.
Second. The synchronising of clocks or other timekeepers by means of an
$ shaped cam or bar acting upon two pins or projections in the lever or pointer to
be corrected, the said cam or lever being preferably moved by mechanism such as
shown in Figures 1 to 5 of the accompanying Drawings.
Third. The arrangement of the cam, as described, wherein the spindle carrying

page_text: the correcting lever is caused to move forward as well as round, substantially as
herein set forth.
Fourth. The means or method described and shown in Figure 5 for the appli.
cation of this Invention to turret or other clocks having heavy movements, or any
mere modification thereof.
In witness whereof, I, the said James Brockie, have hereunto set my hand
and seal, this Thirteenth day of June, in the year of our Lord One
thousand eight hundred and seventy-eight.