Improvements in Apparatus for Synchronizing Clocks.
Year: 1886

page_text: Date of Application, 8th Oct., 1886.
Complete Left, 24th Mar., 1887.
Complete Accepted, 26th Apr., 1887.
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Synchronizing Clocks.
I CHARLES ERNEST HOEFLING, of 19 and 21 Queen Victoria Street, in the City of
London, Superintendent do hereby declare the nature of this invention to be as
follows:
My invention has reference to clock synchronizing apparatus of the kind in which one
or more clocks have their hands set, or moved, to the exact time once an hour, or at any
other prearranged intervals, by means of devices acted upon by an electric current
from a standard or normal clock or time keeper.
In apparatus of this description, as heretofore constructed, there have usually been
two pins, or arms, projecting through the dial of the clock to be sychronized, one at
each side of zero, and, when the current from the standard or normal clock has arrived
at the completion of the hour, the said pins or arms have been caused, by means of an
electro-magnet, armature, and intermediate mechanism, to move to and meet at the
zero point, and in their movement to shift the minute hand exactly to zero, if it is not
there already. When the apparatus works properly the current lasts only a few
seconds and, on its ceasing, the armature and the pins, or arms, are returned by means
of a weight to their normal position where they remain until the current from the
normal clock again arrives.
But it sometimes happens that, owing to the current becoming more or less per-
manent, or to an accumulation of dirt, or to some other cause, the armature remains
in contact with the magnet, so that the pins, or arms, after having been moved to
the zero point, remain there and consequently retain the minute hand and stop the
clock.
The object of my invention is to overcome this objection and, for this purpose, I so
arrange the synchronizing, or setting, devices that if, owing to the current becoming
permanent or to any other cause, the armature remains in contact with the electro-
magnet, the minute hand is not retained and therefore the clock is not stopped or its
regular working interfered with.
I employ, as the devices which act directly upon the minute hand, a pair of arms
which are free to move on horizontal axes or pivots, and have counterweights that

page_text: keep them normally in a horizontal position in line with each other, or approximately
so. The arms have each a tail, and these tails meet or overlap each other in front of
a vertical slot in the clock dial. A pin, which is connected to the armature of the
electro-magnet, projects through this slot. When the current arrives from the standard
clock and the armature is therefore attracted by the magnet, the pin, above mentioned,
moves down the slot and, in so doing, pushes down the tails of the setting arms and
thus causes the arms themselves to rise to the vertical position, that is to say: to zero
and, grasping the minute hand, they set it to zero. Immediately the pin has passed
the tails the counterweights return the setting arms to their horizontal position, clear
of the minute hand. The pin, in again rising after the current ceases, has only to
slightly move the setting arms in passing them, because their tails are bevelled on the
under side. Should the pin fail to rise, owing to the current becoming permanent, or
to any other cause, the setting devices being, and remaining, clear of the minute hand,
the regular working of the clock is not interfered with.
If, instead of acting directly upon the minute hand, the setting devices are arranged to
act upon a false hand behind the dial on the arbor of the minute hand the said devices
will be placed at the back of the dial and the pin connected with the armature need
not then project through the dial; the slot can therefore be dispensed with.
Although I have described my invention as applied to electrically worked synchro-
nizers it is applicable to synchronizers in which the setting devices are operated at
prearranged times from a standard time keeper by other than electrical means,
pneumatic for example.
Data this 8th dox of Ontober 1906
J. C. MEWBURN,
169, Fleet Street, London,
Agent.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Synchronizing Clocks.
I, CHARLES ERNEST HOEFLING of 19 and 21 Queen Victoria Street, in the City of
London, Superintendent, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement:-
My invention has reference to clock synchronizing apparatus of the kind in which
one or more clocks have their hands set or moved to the exact time once an hour or at
any other prearranged intervals by means of devices acted upon by an electric current
from a standard or normal clock or time-keeper.
In apparatus of this description as heretofore constructed there have usually been
two pins or arms projecting through the dial of the clock to be synchronized one at
each side of zero and when the current from the standard or normal clock has arrived
at the completion of the hour, the said pins or arms have been caused, by means of an
electro magnet, armature and intermediate mechanism, to move to and meet at the

page_text: zero point and in their movement to shift the minute hand exactly to zero if it is not
there already. When the apparatus works properly the current lasts only a few
seconds and on its ceasing the armature and the pins or arms are returned by means
of a weight to their normal position where they remain until the current from the
normal clock again arrives.
But it sometimes happens that owing to the current becoming more or less perma-
nent or to an accumulation of dirt or to some other cause the armature remains in
contact with the magnet so that the pins or arms after having been moved to the zero
point remain there and consequently retain the minute hand and stop the clock.
The object of my invention is to overcome this objection and for this purpose I so
arrange the synchronizing or setting devices that if owing to the current becoming
permanent or to any other cause the armature remains in contact with the electro
imagnet the aninute hand is not retained and therefore the clock is not stopped or its
regular working interfered with.
I employ, as the devices which act directly upon the minute hand, a pair of arms
which are free to move on horizontal axes or pivots and have counterweights that keep
them normally in a horizontal position in line with each other or approximately so.
The arms have each a tail and these tails meet or overlap each other in front of a
vertical slot in the clock dial. A pin which is connected to the armature of the electro
magnet projects through this slot. When the current arrives from the standard clock
and the armature is therefore attracted by the magnet the pin above mentioned moves
down the slot and in so doing pushes down the tails of the setting arms and thus
causes the arms themselves to rise to the vertical position, that is to say to zero and
grasping the minute hand they set it to zero. Limmediately the pin has passed the
tails the counterweights return the setting arms to their horizontal position clear of
the minute hand. The pin in again rising after the current ceases has only to slightly
move the setting arms in passing them because their tails are bevelled on the underside.
Should the pin fail to rise owing to the current becoming permanent or to any other
cause the setting devices being and remaining clear of the minute hand the regular
working of the clock is not interfered with.
My invention will be fully understood on reference to the annexed drawings in
which Figure 1 is a face view of a portion of a clock fitted with my improved synchro-
nizing apparatus. Figure 2 is a back view as seen from the line 1---1 in Figure 3,
and Figure 3 is a plan. Figure 4 is a detached view in elevation of the two setting
arms and Figure 5 a plan of the same. a is the clock dial and b the minute hand.
e is an electro magnet in connection with the standard clock from which the electric
current arrives at the completion of every hour. is the armature of the magnet and
e is a weight that normally keeps the armature from the magnet. f is a pin attached
to the armature and projecting through a vertical slot g in the clock dial; when the
armature is attracted to the magnet this pin moves down the slot and while the arma-
ture is returning to its normal position the pin again moves up the slot. h are a
pair of arms free to move on horizontal axes or pivots ii and carrying counter-
weights that keep them normally in a horizontal position as clearly seen in
Figure 1. These arms have each a tail 7 and the two tails inect or overlap each other
in front of the vertical slot g. It will readily be understood that when the current
arrives from the standard clock and the armature d is therefore attracted by the electro
magnet c and the pin consequently moves down the slot g, this pin pushes down
the tails of the arms and thus causes the arms themselves to rise to the vertical
position, that is to say, to zero, as seen in Figure 6; the minute hand is thus set to
zero the armsh grasping between them a pin m on the back of the minute hand.
n is a stop or abutment against which the arms come. Immediately the pin
passed the tails 11 the counterweights kk return the arms to the horizontal position
seen in Figure 1. The tails of the arms being bevelled on the underside the pin / has
only to slightly move the arms in passing them in again rising. It will also be readily
seen that should the pin fail to rise the setting arms
regular working of the clock because they are clear of
The axes or pivots ii of the arms a are shown as
So.
has
will not interfere with the
the minute hand and remain
being in pieces o o fixed to

page_text: the back of the clock dial. The electro magnet c is represented as supported by a
bracket p and the armature by arms qq.
If instead of acting directly upon the minute hand, the setting devices h h are
arranged to act upon a false hand behind the dial on the arbor of the minute hand, the
said devices will be placed at the back of the dial and the pin f need not then project
through the dial; the slot g can therefore be dispensed with. Or, by having the
tails behind the dial instead of in front of it as shown, the pin need not project
through the dial and the slot g is unnecessary.
Although I have described my invention as applied to electrically worked synchro-
nizers it is applicable to synchronizers in which the setting devices are operated at
prearranged times from a standard time keeper by other than electrical means,
pneumatic for example.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim in respect.
of apparatus for synchronizing clocks is:-
1. A pair of setting devices which after every setting operation effected under the
action of mechanism controlled by the standard clock return automatically to their
normal position, whether the said mechanism resumes its normal position or not,
substantially as and for the purpose set forth.
2. The pair of setting arms or devices h h with their tails 11 and counterweights kk
in combination with the actuating pin or device f controlled by the standard clock,
substantially as set forth.
3. Constructing apparatus for synchronizing clocks as hereinbefore described and
represented in the annexed drawings.
J. C. MEWBURN,
169, Fleet Street, London,
Agent.