IMPROVEMENTS IN SYMPATHETIC CLOCKS
Year: 1872

page_text: LETTERS PATENT to Frederick James Ritchie, of the City of Edin-
burgh, Scotland, Watch and Clock Maker, for the Invention of
** IMPROVEMENTS IN SYMPATHETIC CLOCKS."
PROVISIONAL SPECIFICATION left by the said Frederick James Ritchie
at the Office of the Commissioners of Patents, with his Petition,
on the 10th July 1872.
I, FREDERICK JAMES RITCHIE, of the City of Edinburgh, Scotland,
Watch and Clock Maker, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SYMPATHETIC CLOCKS," to be as follows:—
A standard or regulator clock has long been used to transmit at
regular intervals currents of electricity, either of the same kind or
alternatively positive and negative as may be required, to one or more
separate dials, on which the same time is produced as is shewn by the
normal clock.

page_text: The companion or sympathetic clocks in use hitherto have either had
their works propelled by a direct push or beat, transmitted from the
normal clock, without having any maintaining or driving power in them-
selves, or have had a motive power in themselves, which required periodical
winding, either with or without a pendulum, and having their time
regulated or controlled by the pulsations of the normal clock transmitted
in the usual way. Neither of these methods has been at all perfect,
while their first and current expenses are great.
My first improvement consists in giving motion to the pendulum of
the sympathetic or subsidiary clock by transmitting, by means of
electricity or electric or magnetic currents in any of the ordinary known
methods or means, the beats of the normal or regulating clock, without
the aid of any other maintaining or driving power in the sympathetic
clock, which thus requires no attention or winding up, while from the
small battery power requisite to sustain the motion of the pendulum by
this method liability of derangement is removed.
My second improvement consists in propelling a train of wheelwork
(which carries the hands) by the oscillations of a pendulum acting on
two arms or pallets suspended on arbors or springs alternately pressing
by force of gravity, or otherwise, on the teeth of the escapement wheel.
The swing of the pendulum to the one side takes the first arm out of
contact with the escapement wheel, and allows the second arm by force
of gravity to press forward the escapement wheel until the succeeding
tooth rests upon the arc formed on the second arm, beyond which it
is impossible to force onwards the wheel until the return swing of the
pendulum raises the second arm out of action, and allows the weight
of the reverse or first arm to propel the wheel in the way above described.
By this means of propulsion the action or movement of the wheel is
instantaneous, and cannot by any force be carried beyond its proper
point of rest, nor can it be turned backwards, except by a force greater
than the weight of the gravity arms. For larger clocks whose hands
are exposed to the wind I use a detent, which falling into each tooth
when advanced by the gravity arm prevents its being turned back.
My third improvement consists in using a pendulum loaded above its
centre of suspension, so as to beat approximately with the normal
pendulum when it is desirable to have corresponding beats, but where
from want of room this cannot be obtained by a pendulum of the same
length. For this purpose I use a coil or coils of wire or magnetic bars

page_text: below and the same above the point of suspension, working into or
around magnets or coils fixed in the casing, and acted upon by the
electric currents in the usual way.
My fourth improvement consists in the adaptation of the means of
propulsion described above, so as to enable a half seconds pendulum
to beat seconds. For this purpose I use only one gravity arm, having
a jointed arc or pallet, which presses forward the wheel at every alternatë
swing of the pendulum until locked as before on its circular part. The
wheel is then held steadily by a detent while the return swing of the
pendulum withdraws the arm from the wheel and frees the jointed arm,
so that it falls, and is ready to take up the next tooth when relieved
from the pendulum.
My fifth improvement consists in applying the foregoing improvements
to a balance instead of and acting in place of a pendulum.
In these different methods it will be seen that it is the vibrations of
the pendulums or balances, and not the currents from the normal clock,
which are recorded by the wheelwork, so that any accidental stopping
of the current for even several seconds will not affect the time shewn
by the sympathetic clock.
My improvements can all be applied to pendulums, which are of
different lengths from that of the normal clock.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick James Ritchie in the Great Seal Patent
Office on the 31st October 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
JAMES RITCHIE, of the City of Edinburgh, in the Kingdom of Scotland,
Watch and Clock Maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters. Patent, bearing date the Tenth day of July; in the year of our
Lord One thousand eight hundred and seventy-two, in the thirty-sixth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Frederick James Ritchie; Her special licence
that I, the said Frederick James Ritchie, my executors, administrators,

page_text: and assigns, or such others as I, the said Frederick James Ritchie, 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 lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN SYMPATHETIC CLOCKS," upon the condition (amongst others) that I,
the said Frederick James Ritchie, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain 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.
NOW KNOW YE, that I, the said Frederick James Ritchie, do hereby :
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement :-
A standard or regulator clock has long been used to transmit at
regular intervals currents of electricity, either of the same kind or
alternatively positive and negative as may be required, to one or more
separate dials on which the same time is produced as is shewn by the
normal clock.
The companion or sympathetic clocks in use hitherto have either had
their works propelled by a direct push or beat transmitted from the
normal clock without having any maintaining or driving power in
themselves, or have had a motive power in themselves which required
periodical winding either with or without a pendulum, and having their
time regulated or controlled by the pulsations of the normal clock
transmitted in the usual way. Neither of these methods has been at all
perfect, while their first and current expenses are great.
My first improvement consists in giving motion to the pendulum of
the sympathetic or subsidiary clock by transmitting by means of
electricity or electric or magnetic currents in any of the ordinary known
methods or means the beats of the normal or regulating clock without
the aid of any other maintaining or driving power in the sympathetic
clock, which thus requires no attention or winding up, while in con-

page_text: sequence of the small battery power requisite to sustain the motion
of the pendulum by this method liability of derangement is greatly
removed.
This improvement is shewn by means of Figure 1 on Sheet A of the
accompanying Drawings.
A is the pendulum of the regulator clock, which is driven in the usual
manner by clockwork and requires periodical winding up; B and C are
insulated slender springs so placed that the rod of the pendulum A comes
in contact with one or other at each oscillation; D and E are batteries
which may be placed in any convenient position, the positive terminal.d'
of the battery D heing connected with the spring B, and the negative
terminal e¹ of the battery Ẹ being connected with the spring O. The
other terminal of each battery d² and e³ are connected together and sent
to earth. F and F are respectively front and side views of a sympathetic
or subsidiary pendulum which is composed of a coil of insulated copper
wire F³, one end of which terminates in the suspension spring f¹ and
the other in the spring ƒ³, both of which are insulated from each other
and from the fixed suspension piece f³. Another wire connects the
spring with the terminal screw a¹ of the normal pendulum and through
it with its pendulum rod, while a wire leads from the second spring f to
the earth; G and Q are permanent magnets or combination of magnètic
bars having their similar poles placed in proximity, so fixed that the
coil F is free to vibrate over them. The action may be thus explained.
When the normal pendulum A oscillates to the left and comes in contact
with the spring B a positive current from the pole & of the battery D
passes by means of the spring B into the pendulum A, thence by the
terminal screw a and the line wire a³ leading to the screw f' of the
spring f¹ of the subsidiary pendulum F, thence through its ooil F³ to
the springs, and by the screw f" to the earth, and thence to the pole d³
of the battery D. This current while traversing the pendulum coil F³
induces a magnetic action upon the wire causing an attraction to and
repulsion from the respective poles of the permanent magnets G and G¹
which forces the coil and with it the pendulum to swing towards the
left hand. Meanwhile the normal clock pendulum has returned and
broken contact with the spring B and so caused its influence to cease
upon the coil F³. The normal pendulum then oscillates to the right
hand, and coming in contact with the spring O à negative current is
transmitted from the pole e' of the battery E through the spring C and

page_text: the pendulum rod and screw a¹ as before described, but which current
causes repulsion from and attraction to the same poles as before of the
permanent magnets G and G¹ and so imparts motion to the coil in the
opposite direction. These alternate currents of positive and negative
electricity made at regular intervals by the normal clock give motion to
any number of subsidiary pendulums causing them to vibrate in unison
with each other and with the regulating clock.
Very small battery power is required for the purposes described,
inasmuch as the magnetic influence of the current is applied to the
point of the pendulum, where the most powerful effect is produced.
From the momentum of the pendulum also the currents may be
intermitted for several seconds without causing its motion to cease.
Instead of the wire coil being attached to the pendulum rod of the
subsidiary pendulum, and the magnets fixed to the clock case, the
coil or coils may be fixed, and the magnets carried on the pendulum,
as in Figure 2, Sheet A, where H are the magnetic bars, and I, I,
are the coils into which the poles of the magnet enter. One end of
the wire in one coil is connected to one end of the wire in the other coil,
and the other ends are led one to the normal pendulum, and the other
to the earth. Instead of magnetic bars, coils of wire rendered magnetic
by the passing of a current may be substituted. In the finer class of
regulators I prefer using a pair of springs acted on by a wheel in the
train of clockwork, and making contact alternately with the batteries,
instead of the springs acted upon by the pendulum rod as before
described.
My second improvement consists in using a pendulum loaded above.
its centre of suspension, so as to beat approximately with the normal
pendulum when it is desirable to have corresponding beats, but where
from want of room this cannot be obtained by a pendulum of the same
length. For this purpose I use a coil or coils of wire or magnetic bars
below and the same above the point of suspension, working into or
around magnets or coils fixed in the casing, as represented in Drawings,
Figure 3, which are respectively a front and side view. O and O¹ are
coils of wire mounted on a frame R, R, R, R, and suspended on the fixed
piece O by the springs O³ and O. The magnets P and P¹ having their
similar poles in proximity are placed so that the coils vibrate freely
over them. The currents from the normal clock enter by the spring O³
into the coil O, thence into the coil O', and pass on by the spring O* to

page_text: the line wire. The action is similar to that in Figure 1, but doubled
by passing through two coils. The projecting part Q takes the place
of the pendulum rod in Figure 4 in imparting motion to the studs m¹
and n¹ attached to the pallets M, N.
My third improvement consists in propelling a train of wheelwork
(which carries the hands) by the oscillations of a pendulum acting on
two arms or pallets suspended on arbors or springs, alternately pressing
by force of gravity or otherwise on the teeth of the escapement wheel.
This improvement is represented in the Drawing, Figures 4 and 5,
Sheet B, and may thus be described:-L is the escapement wheel,
carrying the seconds hand, and is cut into thirty teeth; m and n are
arbors. carrying pallets M. and N, the points or ends of which pallets
press by force of gravity on the teeth of the 'scape wheel, causing it to
move in the forward direction till stopped by the arc formed on each
pallet respectively. On the same arbors are also fixed arms "carrying
studs m¹ and n¹ to either side of the pendulum rod F.so as to be
alternately acted on or raised by oscillation of the pendulum. The
wheel L is shown at rest on the pallet M, the end of which presses
against the one tooth O, while the succeeding tooth P rests upon the
arc on the under surface of the pallet. When the pendulum oscillates in
the direction of the arrow the stud n¹ by force of gravity follows it, and
(after the pallet M. has been removed by the action of the pendulum
upon the stud m¹) allows the arm carrying the pallet N by force of
gravity to move forward the tooth S against which it has been pressing
until the tooth t is stopped by the arc formed on the upper side of the
pallet N. The reverse oscillation of the pendulum operates upon the
pallets in the same way, but in the reverse order. Additional gravity
weights may be added if necessary on arms m³ and n³ secured to the
arbors. Instead of arbors suspension springs may be used, and the
elasticity of springs may be substituted for the action of gravity in
propelling the wheel. The motion of the seconds hand is instantaneous
and rests "dead" on the division of the dial, and no force, however
great, will cause the wheel to move forward at any time beyond the
arc of the pallet on which it is resting. The wheel cannot be turned
backward, except by a force greater than the weight of the gravity
arms. For clocks in exposed situations a simple detent or catch is
provided, which falling into each tooth when advanced by the pallets
prevents any force from turning the wheel backwards..
.

page_text: My fourth. improvement consists in the adaptation of the means of
propulsion described above so as to enable a half seconds pendulum to
beat seconds. For this purpose I use only one gravity arm having a
jointed pallet, which presses forward the wheel at every alternate swing
of the pendulum until locked as before on the arc on the upper side of
the pallet, as shewn in Figure 5, Sheet B. T is the 'scape wheel carry-
ing the seconds hand, and is cut into sixty teeth. The arbor carries
an arm with a jointed pallet R, the weight of which is slightly over-
balanced by an adjustable poise P. Two studs p¹, p³, are placed to limit
the play of the pallet. The end of this pallet pressing against the tooth
of the wheel causes it to move forward until the succeeding tooth
touches the arc and presses the pallet against the lower stud p¹, beyond
which no force will cause the wheel to move. Another arbor S carries
an arm S¹ with a small notch which falls upon the point of a tooth of
the wheel, and until relieved no force will cause the wheel to move
either backwards or forwards. When the pendulum F oscillates towards
the right hand in the direction of the arrow it leaves the notch on S¹
holding the wheel firm, and then raises the arm r² (carrying the jointed
pallet) out of contact with the wheel. When the aro has cleared the
tooth of the wheel the point of the pallet is raised by the preponderance
of the weight P, and will on the return swing of the pendulum press
against the following tooth of the wheel in readiness to move it forwards
as soon as the pendulum rod acting on the stud S³ raises the arm S¹ from
the tooth. The wheel is then carried forward by the weight of the
pallet R until locked as before.
Figure 6, Sheet B, is an enlarged drawing of the pallet, R, Figure 5.
H is the arm carrying it; m is the framework for carrying the studs p', p²,
and is fixed to arm H. N is the part of the pallet which moves on the
centre K, and is loaded with the adjustable poise P.
My fifth improvement consists in applying the foregoing improve-
ments to a balance instead of and acting in place of a pendulum. The
escapement I have invented for this is shewn on Figure 7, Sheet B.
y is a wheel in connection with the train of wheelwork carrying the
hands, and is held steady by a very slender spring Z. X is a roller
fixed to the arbor of the balance, and has a jointed pallet projecting
beyond its periphery, which is pressed outwards by a slender spring.
When the balance vibrates in the direction of the arrow the projecting
pallet carries forward the tooth of the wheel. The pallet in returning

page_text: clears the tooth by the action of the jointed arm, and being then pressed
outwards by its spring is in readiness to carry forward the succeeding
tooth upon the next vibration of the balance.
In all these different methods it will be seen that it is the oscillations
of the pendulum or balances, and not the currents from the normal
clock, which are recorded by the wheelwork, so that any accidental
stopping of the current for even several seconds will not affect the time
shewn by the sympathetic clock.
My improvements can all be applied to pendulums which are of
different lengths from that of the normal clock.
new,
Having explained the way in which my improvements are worked out
I have to mention that I do not claim all that has been described as
but that what I claim as my Invention is, the giving motion to
the pendulums or balances of sympathetic clocks entirely by currents of
electricity transmitted from the normal clock without the aid of any
other maintaining or driving power in the sympathetic clock, and that
substantially by the means herein set forth and partially illustrated on
the accompanying two Sheets of Drawings.
In witness whereof, I, the said Frederick James Ritchie, have here-
unto set my hand and seal, this Thirteenth day of September,
in the year of our Lord One thousand eight hundred and seventy-
two.