IMPROVEMENTS IN SYNCHRONIZING CLOCKS
Year: 1883

page_text: LETTERS PATENT to Herbert John Allison, of the firm of Allison Brothers,
""
Patent Agents, of Southampton Buildings, London, for an Invention of
"IMPROVEMENTS IN SYNCHRONIZING CLOCKS communicated to him from
abroad by Robert. W. Wilson, of New Haven, Connecticut, United States of
America
COMPLETE SPECIFICATION filed by the said Herbert John Allison at
the Office of the Commissioners of Patents on the 21st November 1883.
HERBERT JOHN ALLISON, of the firm of Allison Brothers, Patent Agents, of
Southampton Buildings, London, "IMPROVEMENTS IN SYNCHRONIZING CLOCKS"
communicated to me from abroad by Robert. W. Wilson, of Newhaven, Connecticut,
United States of America.
Figure 1, represents a front view, a portion of the front plate broken away for
convenient illustration, and showing the parts in their normal condition.
Figure 2, top or plan view.
Figure 3, front view illustrating the operation of the synchronizing mechanism
on receiving the impulse.
This invention relates to an improvement in device for synchronizing clocks,
that is to say at a predetermined time to automatically set or turn the minute
pointer to a fixed point, if during the previous period it has varied from the true
time, the setting being performed through an impulse received from a distant or some
central point whereby many clocks on the circuit or on different circuits in connec-
tion may be at some predetermined time set to the exact time notwithstanding a
variation either faster or slower during the previous period.
In mechanism for thus synchronizing clocks as hitherto generally employed, a
strong current or impulse has been necessary in order to turn the pointers; in
some cases it is the power of the current or impulse which turns the pointers as in
the well known Lund patents. In others, as for instance in an American patent
granted to the said Robert W. Wilson on November 7th, 1882, N° 267,300, the
current or impulse is required to remove or disconnect the power of the clock
which turns the pointers, and permit the action of a spring to turn the pointers to
the predetermined position. In either case the impulse or current must be very
strong.
The object of my invention is to avoid the necessity of a strong current or
mpulse, and at the same time prevent the power from running down should the

page_text: circuit remain closed, or the impulse continue, and the invention consists principally
in the combination of a clock movement carrying the time pointers, a train of
wheels and power for driving the same independent of the clock movement, with
mechanism whereby a circuit closed or impulse received will liberate the power
to cause the pointers to be turned and arrest the action of the power after
synchronizing shall have taken place whether or not the impulse continue or the
circuit be broken, that is to say, independent of the impulse giving or releasing
device.
In illustrating my invention I show only a general view of the clock movement
which carries the minute pointer A, this being sufficient for the illustration of my
invention, as the mechanism of the clock may be any of the known clock move-
ments. At some convenient position, and preferably as here represented the
independent power for synchronizing is arranged directly over the clock movement,
but it will be understood that it is entirely independent of the clock movement, and
in no connection therewith. This independent power as here represented consists
of a spring B applied to a main wheel by a pawl and ratchet connection in the
usual manner of applying coiled springs to drive clock movements, the spring being
wound in the same manner, a device too well known to require particular
description.
At a position each side of the point where the synchronizing is to be performed,
here represented as at twelve o'clock, two wheels D, E, of equal diameter are
arranged in suitable bearings and geared together. The power is communicated to
a pinion F on the shaft of one of the wheels from the main wheel by an interme-
diate wheel G and pinion H, as seen in Fig. 2. From the shaft of one of the wheels,
say D, an arm a extends radially, and revolves with that shaft. I is the magnet
arranged in some convenient position near or in connection with this independent
movement; K, the armature on the end of an arm L, which extends from a rock-
shaft M. The usual circuit connections are made so that when the circuit is closed
the armature will be drawn to the magnet, and when released will rise from it,
caused so to do by the action of a spring N, or otherwise, represented in the
drawing as raised, that is the circuit open. From the same rock-shaft M an arm P
extends upward, its end turned at right angles to the arm to form a hook b, and
when the circuit is open as shown, the arm a, which extends from the shaft of the
wheel D, stands beneath the hook 6 of the arm P, this arm P therefore holds the
wheel D from revolution, and consequently the power of the main spring in
suspense, but when the circuit is closed, as seen in Fig, 3, the arm P of the rock-
shaft M is drawn out of the path of the arm a so that when the circuit is so closed
the wheel D is free to revolve, as also the wheel E, the two revolving alike. On
the forward end of the shaft of the two wheels D, E, there is arranged respectively
a finger d, e, which extends radially from the shaft; the end of the fingers is turned
outward, as seen in Fig. 2, so as to stand in the plane of the pointer A. Now
suppose the clock to be slow at the time the synchronizing is to be produced, say
standing in the position seen in Fig. 1. At the predetermined time the circuit is
closed, which instantly releases the arm a, and permits the independent movement
which will impart revolution to the wheels D, E, in the direction indicated
by arrows, and as the fingers come around the one at the left will strike the
pointer and bring it to the vertical position between the two fingers, as seen in
Fig, 3, which is the true time. The circuit broken the wheels will continue their
movement until the arm a again comes into engagement with the arm P, and will
there be arrested, the wheels D, E, having made a full revolution, and will so
remain until again the circuit is closed, when they will operate in the same manner.
If instead of slow the pointer is fast, then the finger e on the wheel E will operate
upon the opposite side of that pointer, and return it to the true position between
the two fingers, as seen in Fig. 3. The continued revolution of the wheels after the
synchronizing is produced, brings the fingers to a position out of the path of the
pointer so as not to interfere with its revolution during the rise between the times
of synchronizing.
to run,

page_text: If the circuit should remain closed the independent power would continue to
revolve the wheels D, E, but if the circnit be broken during the first revolution of
the wheels D, E, which it easily may be, then the independent power will be
arrested as before described, but to provide against a longer closing of the circuit,
and therefore prevent the wheels from continually revolving, I arrange an arm f
projecting radially from the shaft of the wheel E, but at about a quarter of a turn
back of the position of the arm a, on the other wheel. This arm extends into the
same plane as the hooked end b of the lever P, and so that when the circuit is
closed, as seen in Fig. 3, the arm ƒ will engage the hook b of the arm P and arrest
the further running of the independent movement until such time as the circuit
shall be broken, and then when the circuit is broken the arm P of the rock-shaft
will escape from the arm f of the wheel E and pass into a position to engage the
arm a of the wheel D, as in Fig. 1, the extreme vibration of the arm P being from
a position in the path of one arm a into the path of the arm f and return, hence
but a single revolution of the wheels D, E, can occur at one breaking and closing
of the circuit.
This stopping of the independent movement after closing the circuit occurs after
the fingers d, e, have passed to a position above the ends of the pointer, so that the
pointer may escape from the fingers and move on its course, thus it will be seen
that while the synchronizing is positive, the synchronizing devices cannot by any
possibility interfere with the proper running of the clock, and should the circuit be
accidentally closed and held closed during the time between two synchronizing
periods it can have no effect upon the clock, and thus will not interfere with the
regular running of the clock, as many of the synchronizing devices heretofore
constructed will do.
To prevent the wheels D, E, from running too rapidly I arrange a brake R upon
one of the wheels, or a fly may be introduced, or other known device to prevent
the too rapid running of the wheels under the influence of the power when
liberated.
All the power that is required for the magnet is simply to turn the arm P from
its engagement with the arm a of the synchronizing wheel; that wheel being a
rapidly revolving wheel is capable of imparting but a very slight power or pressure
upon the arm P, hence the electric power required to liberate the synchronizing
mechanism is very small when compared with the electric power required where
that power is applied directly to the turning of the pointers, or where applied to
relieve the pointers from the power of the clock work, as in the patent before
mentioned. The arrangement of a mechanism independent of the clock movement
enables the application of a synchronizing mechanism to many clocks where it
would be difficult to apply it in rear of the dial, as in the Lund and other
patents.
I have represented the clock train as actuated by a spring acting directly on the
main wheel, but it will be understood that this may be a weight, or other known
means for applying power thereto.
I have represented the impulse as being received through an electrical circuit,
but this impulse may be received through any of the known impulse giving
mediums, it only being essential that such impulse received shall be sufficient to
turn the arm P from its engaged position, that is simply to liberate the power.
I have represented the apparatus as operated upon an open circuit, but it will be
understood that if the circuit be a closed circuit the action will be reversed.
Instead of employing the wheels D, E, and their respective arms
as the
synchronizing device, other mechanism may be employed through which the
independent movement or train of gearing may act to turn the pointer at the
predetermined time.
Instead of applying this independent power or train of gearing to operate the
synchronizing mechanism, that mechanism may be held in suspense by this inde-
pendent train of gearing, and so that when the power of that train is liberated by
the impulse it will liberate the synchronizing device and permit it to perform its

page_text: work, and then after it has performed the work of synchronizing to remove it from
its point of action or connection so as to be out of the way and not to interfere
with the turning of the pointers.
I do not wish to be understood as limiting my invention to the particular
device between the independent train of gearing and the pointers to be acted upon,
the essential feature of my invention being the application of a train of gearing
forming a power independent of the clock movement, combined with mechanism
between said independent train and the pointers to be operated upon, the power
of said independent train also independent of the impulse giving devices, the said
impulse giving devices being employed only to permit it to act at a predetermined
time, and having combined therewith mechanism whereby if the liberating force of
the impulse be continued the action of the power which operates the synchronizing
mechanism will be arrested, that is to say independent of the impulse giving or
receiving device.
Having thus described the nature of the said invention, what I claim is :-
First. The combination of a clock movement carrying the time pointer, a train
of wheels and power for driving the same independent of the clock movement,
mechanism substantially such as described between said train and the pointers,
whereby at a predetermined time said independent train will act upon the pointers,
a lever, one arm of which is arranged to receive the impulse and in connection with
said train, whereby the movement of said lever under the said impulse will
liberate the power to cause the wheels of the train to revolve and operate said
synchronizing mechanism, and also arrest the further revolution of the train after
the synchronizing shall have been produced, such arrest being independent of said
impulse, that is, whether or not the power of the impulse be broken or continued,
substantially as described.
Second. The combination of a clock movement carrying the time pointer, a train
of wheels and power for driving the same independent of the clock movement,
mechanism substantially such as described between said train and the pointers,
whereby at a predetermined time said independent train will act upon the pointers,
a lever, one arm of which is arranged to receive the impulse and in connection
with said train, whereby the movement of said lever under the said impulse will
liberate the power to cause the wheels of the train to revolve and operate said
synchronizing mechanism, and also arrest the further revolution of the train after
the synchronizing shall have been produced, and the said lever upon being released
from said impulse will again liberate the said power to cause a slight movement of
the synchronizing mechanisin before said lever will again engage and arrest the
inovement of the train preparatory to the next synchronizing operation, substantially
as described.
Third. The combination of a clock movement carrying the time pointers, a train
of gearing and power for driving the same, independent of the clock movement, the
wheels D, E, carrying respectively the synchronizing fingers d, e, the magnet I,
armature lever L, arm P in connection with said armature lever, the arm a in
connection with the said wheel D, and arm f on the wheel E, substantially as
described.
In witness whereof, I, the said Herbert John Allison, have hereunto set my hand
and seal, this twenty-first day of November in the year of our Lord one thousand
eight hundred and eighty-three.