An Improved Method of Synchronizing Clocks, and Apparatus therefor.
Year: 1894

page_text: Date of Application, 17th Mar., 1894
Complete Specification Left, 15th Dec., 1894-Accepted, 17th Apr., 1895
PROVISIONAL SPECIFICATION.
An Improved Method of Synchronizing Clocks, and Apparatus
therefor.
I, WILLIAM CRUYT, of 42 Rue des Bogards, Brussels, in the Kingdom of
Belgium, Managing Director of the "Société La Précision," Electrical Clock
Manufacturers, do hereby declare the nature of this invention to be as follows:-
This invention relates to a method of synchronizing clocks and to apparatus
therefor, and comprises the improvements hereinafter indicated.
The object of my said invention is to provide improved means whereby a clock
or set of clocks may be synchronized by a standard or mother clock which at a
predetermined hour makes an electric circuit and so gives rise to a current for a
very short time.
The arrangements hitherto devised have operated somewhat in the manner
following that is to say :-At a suitable interval of time before a predetermined
hour the standard or mother clock closes a connection, and when the clock to be
regulated reaches the hour it also makes a connection so that a circuit is formed
in which an electric current flows through the connection before established by
the mother clock and also through the connection made by the clock to be
regulated, this current stops the clock which is to be regulated. When the
mother clock reaches the hour, it breaks the connection which it before established
and thus re-starts the clock to be regulated. It will be seen from this description
that the wires leading from the mother clock to the clock to be regulated must
be in use for some time in order to accomplish the regulation.
According to my invention I so provide that the clock to be regulated, herein-
after called the second clock, stops itself by electrical or mechanical means as
soon as it reaches the predetermined hour, and is re-started by a current of very
short duration which is caused to flow by the mother clock when it reaches the
predetermined hour. By this means the wires from the mother clock are only
used for a very short period of time.
I also provide according to my invention a safety device by means of which, if
the mother clock should fail to re-start the second clock, the said second clock
will re-start itself after the lapse of a suitable interval of time.
The second clock is as is customary regulated so as to gain a few seconds per day
on the mother clock.
According to one method of carrying out my invention I provide a local circuit
which contains an electromagnet and two contact switches.
One of the switches is closed and opened at short intervals as long as the second
clock is going. The other switch is automatically closed by any suitable means as
soon as the said second clock reaches the predetermined hour, and is also arranged
to be opened by a current sent through a circuit which circuit is closed when the
mother clock reaches the predetermined hour.
The operation of synchronizing is as follows. The second clock being slightly
in advance of the mother clock reaches the predetermined hour and closes the
local circuit by means of the second switch above mentioned. The current

page_text: flowing in the local circuit then stops the clock by means of an electromagnet
and suitable mechanism. When the mother clock reaches the predetermined hour
it causes a current to flow which current breaks the local circuit at the second
switch and thus re-starts the clock. It will be observed that the current sent
through the main circuit by the mother clock may be of very short duration
since as soon as the second clock starts again it breaks the local circuit by the
first switch above mentioned.
I provide a safety device which re-starts the second clock by breaking the
local circuit if the standard clock fails to do so as hereinabove mentioned. For
this purpose the second clock is furnished with electrical winding up gear which
is put in operation whenever the said clock makes the local circuit. This may
be done by so arranging a lever, for instance one of the levers of the striking
part of the clock, that the local circuit cannot be made until the lever is lowered.
The lowering of the lever makes contact for the winding up circuit which causes
the winding mechanism to operate to restore the lever to its original position.
This takes a longer period of time than the clock gains on the standard clock per
day so that if the synchronizing mechanism acts at all it will act before the lever
has reached its normal position. If however the standard clock fails from any
cause to act on the synchronizing mechanism the lever on regaining its normal
position breaks the local circuit and re-starts the clock.
In another method of carrying out my invention I provide mechanical means
for actuating a detent which stops the second clock as soon as it reaches a pre-
determined hour. The electrical device for re-starting the clock consists of an
electromagnet which acts upon the detent so as to cause it to release the pendulum
or otherwise re-start the clock when a current is sent round the magnet. The
current which lasts for a very short time is controlled by the standard clock as
hereinbefore mentioned.
The stopping mechanism is preferably constructed as follows. The detent is
pivoted to a fixed part of the frame or case and has pivoted on itself a lever
which is provided with two stepped portions or notches. These stepped portions
engage with a pin on a second lever also pivoted to the frame. A spring may be
provided which maintains the notched lever in contact with the pin on the second
fever. The said second lever is supported by a cam disc which is rotated by a
suitable automatic winding device as soon as the second clock reaches a pre-
determined hour, the time required for the cam disc to make one revolution
being greater than the period of time which the second clock gains on the standard
clock in a day. Under the normal conditions the uppermost step or notch of the
notched lever is supported on the pin of the second lever which second lever is
in turn supported by a projecting part of the cam disc and the detent is not in
engagement with the pendulum or other going portion of the clock. When the
predetermined hour is reached by the second clock the cam disc is caused to
rotate as hereinabove indicated. The second lever then drops a short distance as
the projection on the cam disc moves away and the stepped lever also drops
allowing the detent to rise and stop the clock. If now the mother clock reaches
the predetermined hour it makes a circuit and a current flowing round the electro-
magnet above-mentioned causes it to act on the detent lever to raise it and put the
detent out of gear so as to re-start the second clock. The stepped lever being
raised with the detent lever engages by its second or lower notch with the pin on
the second lever and maintains the detent lever in a raised position although no
current may be flowing round the electromagnet. The cam disc still revolving
approaches its original position and a second projection thereon strikes the tail of
the notched lever causing the second notch to become disengaged from, and the
first or upper notch to become engaged with, the pin on the second lever. As soon
as this has occurred the first mentioned projecting part of the cam disc raises
the second lever and so returns all the parts to their normal position. The winding
mechanism then stops. Should no current be caused to flow in the electromagnet
the second clock will not be re-started until the cam disc has completed its

page_text: revolution and will not of course be synchronized by the mother clock but will
be slow.
Dated this 17th day of March 1894.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
An Improved Method of Synchronizing Clocks, and Apparatus
therefor.
I, WILLIAM CRUYT, of 42 Rue des Bogards, Brussels, in the Kingdom of
Belgium, Managing Director of the "Société La Précision," Electrical Clock
Manufacturers, do hereby declare the nature of this invention and in what manner
the same is to be perforined, to be particularly described and ascertained in and
by the following statement :-
This invention relates to a method of synchronizing clocks and to apparatus
therefor, and comprises the improvements hereinafter indicated.
The object of my said invention is to provide improved means, whereby a clock
or set of clocks may be synchronized by a standard or mother clock which ai a
predetermined hour makes an electric circuit and so gives rise to a current for
a very short time.
The arrangements hitherto devised have operated somewhat in the manner
following that is to say :-At a suitable interval of time before a predetermined
hour the standard or mother clock closes a connection, and when the clock to be
regulated reaches the hour it also makes a connection so that a circuit is formed in
which an electric current flows through the connection before established by the
mother clock and also through the connection made by the clock to be regulated,
this current stops the clock which is to be regulated. When the mother clock
reaches the hour, it breaks the connection which it before established and thus
re-starts the clock to be regulated. It will be seen from this description that the
wires leading from the mother clock to the clock to be regulated must be in use
for some time in order to accomplish the regulation.
According to my invention I so provide that the clock to be regulated, herein-
after called the second clock, stops itself by electrical or mechanical means as soon
as it reaches the predetermined hour, and is re-started by a current of very short
duration which is caused to flow by the mother clock when it reaches the
predetermined hour. By this means the wires from the mother clock are only used
for a very short period of time.
The second clock is as is customary regulated so as to gain a few seconds per day
on the mother clock.
3
The accompanying drawing represents a form of device adapted for use when
the line is at disposal only during the time the regulation is being effected.
The regulating apparatus comprises a clockwork moving very rapidly at the time
of the disengagement which may be determined at any given moment by the
second clock. The principal shaft of the wheel work carries exteriorly a disc with
a lateral pin t and a cam which moves with it during the regulation. Normally,
that is to say at rest, the cam F is placed above in the vertical plane passing
through the centre of the disc and upon the cam bears a stud or projection on a
horizontal lever Q pivoted at one of its extremities at O"; laterally from the
lever Q projects a pin s upon which will bear one or the other of the notches a
of a lever N suspended at O' to a rocking lever M and always tending to move
towards the pin under the pulling action of a spring m. The rocking lever M
placed at definite height above the lever Q terminates at one extremity in an

page_text: articulated hook V which normally allows the pendulum R to pass, and at the
other extremity it carries the armature S of the electromagnet E included in the
circuit.
.
The drawing shows the parts in their normal position or at rest; it will be seen
that the second clock is not influenced, even if the current passes through the line
for other service and attracts the armature, because it lowers the hook V which
cannot rise above the position which is assigned to it by the notch bearing upon
the pin on descending again. The regulation will thus be easily understood.
Supposing that, the second clock is 10 seconds in advance. Arriving at about this
time before twelve it disengages the clockwork which moves at an accelerated
velocity; the cam F turning with its disc in the direction of the arrow, leaves the
stud which falls with the whole system upon the periphery of the disc, thus
raising the hook V and stopping the second clock. On the arrival of the regulator
at twelve the current is sent from any central point through the line of the
electromagnet E which attracts the armature S, lowering the hook V and liberating
the pendulum R. At the moment when the armature S is attracted the notch
of the lever N, having been raised independently of the lever Q. will bear, under
the action of the spring m upon the pin s, thus keeping the hook V lowered without
the ulterior intervention of the electromagnet so that the line can thus again be utilized
for other services. In the meanwhile the cam F has arrived before the other side
of the stud g which it will raise to its normal position with its lever Q; now this
movement would be impossible if the pins remained in the notch r', from which it
must therefore be disengaged at the same moment. This disengagement is effected
by the lateral pint of the dise which has arrived at the same moment before the
tail-piece of the lever N which it pushes back passing below its extremity in order to
move to the other side, while the notch r re-descends upon the pin s, placing the
whole again in the normal position upon the cam F at the moment when the disc
ceases to move with the clockwork which actuates it and causes it to recommence
exactly the same operations in each fresh regulation.
The clockwork employed for actuating the cam disc F may be wound up at fixed
periods exactly like an ordinary clock by the aid of suitable key or it may also be
wound up automatically.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, declare that what I
claim is: :-
In a regulating apparatus for synchronizing a set of clocks the combination with
the electromagnet of the regulating circuit of a detent not included in the circuit
and bearing upon a cam disc actuated by a clockwork the detent consisting of a
simple lever combined with an intermediate lever having two notches bearing upon
a pin of the detent with a rocking lever having a stop hook and an armature to
which it is articulated in order to stop by the hook the pendulum by reason of the
fall of the system on the passage of the cam disc and in order to put it in motion
again at a given moment by the momentary attraction of the armature of the
rocking lever by the electromagnet, the intermediate lever then keeping the stop
hook lowered and bringing back the whole of the regulating apparatus to the
normal position by its combination with a lateral pin of the cam disc, the whole
substantially as described with reference to the accompanying drawing and for the
purpose specified.
ני.
TY
1
1 1005
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.