Improvements in or appertaining to Electrical Clocks and similar Instruments.
Year: 1895

page_text: Date of Application, 23rd Jan., 1895
Complete Specification Left, 23rd Oct., 1895--Accepted, 23rd Apr., 1896
PROVISIONAL SPECIFICATION.
Improvements in or appertaining to Electrical Clocks and similar
Instruments.
We, FRANK HOPE-JONES of Prenton Road West, Birkenhead in the County
of Chester, Electrician, and GEORGE BENNETT BOWELL of Sissinghurst, in the
County of Kent, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
Whereas in electrical clocks and the like up to. the present time considerable
difficulty has arisen owing to the unreliability of the electrical contacts and the
general complication of the mechanism made use of:
This, our invention relates in part to a new device whereby all the energy
required to maintain the swinging of the pendulum or balance wheel in the time-
piece, or to drive the striking train or other similar mechanism is mechanically
transmitted through the electrical contact surfaces, thus ensuring absolute reliability.
with regard to the electrical circuit or circuits. +
As an illustration of one method in which this may be accomplished but without
in any way binding ourselves to this alone, we will describe the following:-
Motion is imparted to the clock by means of a weight transmitting its energy
through a click and ratchet-wheel, a magnet being employed to replace the weight
in such a position that it may operate upon the next tooth after it has descended a
certain distance. The circuit of the electro-magnet and, its battery is closed by a
contact of the moving weight with: the armature which is at rest, the electro-
magnet thus being energized, the armature transmits its energy, through the
electrical contact, the circuit, being broken by the sudden arrest of the said
armature against a fixed stop, no such stop being provided for the weight at that.
point.
4
This our invention also relates to a contact, one moving part of which is driven
against a spring or weight by a ratchet wheel. or its equivalent upon the train
through the medium of a link. This link is so arranged as to be knocked out of
engagement with its driving tooth at the completion of the stroke of the armature
of the electro-magnet employed to wind-the-clock.
A
It is generally advisable to prevent the pressure.being taken off the escapement
during the operation of electrical winding, as it is very desirable that a clock.
which may be used to control other dials should be a reliable-timekeeper. It will
be obvious that this object has been in view in the design of the controller as above
described, particularly with regard to the even tension upon the going train. The
maintenance of the pressure upon the going train during electrical winding may be
accomplished in the following manner-
The ratchet wheel as described above may, be mounted loosely on the arbor
connecting it with the train, a spring being arranged between them to transmit the
whole or a part of the power derived from the weight. A click is provided in
connection with the ratchet wheel in order to prevent a backward movement of
the said ratchet wheel when the pressure of the weight is relieved.
Or if desired the electrical driving movement as above described may be in, part
luplicated and arranged so that one weight or spring exercises its force upon the
escapement at the moment of replacement of the other.
Or this may be done by means of an additional electro-magnet controlled by the

page_text: same circuit; or the electro-magnet used for winding may also be adapted for this
purpose.
It will be understood that we have so far referred to a single electric clock.
This clock we term a "controller." When it is desired that time should be
indicated in additional places the use of similar clocks with pendulums or balance
wheels in such places may be dispensed with.
For this purpose we employ novel methods of propelling and locking the fingers
on subsidiary dials or other instruments by means of the intermittent electric
current governed by the contact in the "controller'
" as above described.
One such method consists of toothed wheels driven by pallets entering against
the inclined surfaces of their teeth; the pallets being arranged so that by means of
springs or similar devices the one may gain upon the other during a portion of the
cycle of operations, or the wheels may be so arranged that the wheel being driven
by one pallet may be caused to gain upon the wheel being released by the opposite
pallet, the object of either of the above arrangements being to carry the hands
through that portion of their cycle which would otherwise be a dead centre.
In another method the clock is constructed upon ordinary lines in that it is
driven by a spring or weight and controlled by an escapement, the winding of the
spring or weight and the action of escapement being simultaneously effected by
means of an electro-magnet in the circuit as above described; or the escapement
may be combined with the pawl which connects the spring or weight to the wheel
work..
:
It will be obvious that the apparatus above described as the "controller" need
not be provided with indicating hands.
It will be readily understood that in the complete system of electrical clocks as
above described, convenient switches may be provided by which the hands upon
the dials in the circuit may be set on or put back without in any way interfering
with the vibrations of the pendulum.
To set the clocks forward a push is provided to operate the circuit of the dials
and their battery. To set the clocks back a two way switch is employed, the
movement of which disconnects the dials and their battery from the controller and
its battery until replaced into its normal position. This switch may be so arranged
that it is automatically replaced after any desired interval of time. This may be
accomplished by the use of a rotating ratchet wheel and a lever furnished with a
click. The switch is held in its normal position by the lever and when the clocks
are to be set back the lever is drawn the desired distance away from the switch,
the click passing over the teeth of the ratchet wheel, so that in due time, the said
lever returns and replaces the switch.
The striking gear is arranged as follows:-
A dividing plate may be driven by any electro-magnetic device, preferably that
described above, against an air or other resistance which may take the usual form
of a fan or fly, the train being locked on the dividing plate alone by a detent
operated by an electro-magnet energized momentarily at the hours or hours and
quarters. In some cases it is advisable to provide the detent with a spring which
causes it to move in the reverse direction to the dividing plate at the moment of
disengagement. To synchronise a series of these clocks they are connected to a
line upon which an electrical pressure is exerted at certain periods determined by
the standard time-piece; in the event of the clock being fast or slow a circuit is
formed from the line through a commutator and one or other of two electro-
magnets so arranged as to increase or diminish the free length of the pendulum or
its equivalent.
Turret clocks may be controlled by the apparatus above described, whether the
said turret clocks are driven by weights, or by hydraulic or electric power.
'
We will describe our apparatus as being electrically driven from a local circuit
though it will be understood that we arrange the same action when making use of
weights or water as a motive power, detents or valves and barrels or cylinders
being substituted for the parts here described as switches, and electro-magnets.

page_text: One part of a circular insulated-gap switch is driven by a "dial" movement
from any time circuit governed by a controller as above described; the other
portion of the said switch being turned by the centre wheel of the secondary
mechanism. This gap-switch closes a local circuit through a motor, this circuit
being broken from a part of the going train or by the gap-switch itself.
In the
case of a turret clock of unusual size, a relay may be employed.
By this arrangement it will be seen that not only is the train governed under
normal conditions by the dial movement and gap-switch, but in case of a temporary
failure of the local or power circuit, synchronisation is re-established between the
primary time circuit and the hands of the turret clock when the failure of the
local circuit is rectified.
'
Dated this oond d
1005
i
Improvements in or appertaining to Electrical Clocks and similar
Instruments.
We, FRANK HOPE-JONES of Prenton Road West, Birkenhead, in the County
of Chester, Electrician, and GEORGE BENNETT BOWELL of Sissinghurst in the
County of Kent, Electrical Engineer, 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 :-
Whereas in electrical clocks and the like up to the present time considerable
difficulty has arisen owing to the unreliability of the electrical contacts and the
general complication of the mechanism made use of:
This our invention relates in part to a new device whereby all the energy
required to maintain the swinging of the pendulum or balance wheel in the time-
pièce, or to drive the striking train or other similar mechanism is mechanically
transmitted through the electrical contact surfaces, thus ensuring absolute reliability
with regard to the electrical circuit or circuits.
The method in which this is accomplished may be described with reference to
C C¹ are
Figure 1 in which B is a pendulum supported by suspension spring s.
two adjustable weights on the driving levers or gravity pieces, c1 c2, centred at b¹ b*
and limited in stroke by the banking pins d³ d'. d, d' are armatures also centered
at 1 and 2, in the fields of the electro-magnets D D₁ and adapted to lift the
driving levers alternately by means of the hooks e e¹. Said driving levers operate
the pendulum through their lower arms and are platinized at the points of contact
with the latter c³ c. X. is an electrical indicating dial, either of one of the forms
to be shortly described or of any known design capable of showing the time-keeping
performances of the pendulum B.
In the drawing, the pendulum is shown travelling towards c³. The lower end of
the lever is in electrical connection with the upper end of the pendulum rod and
the circuit is from the battery through line 3 magnet D, line 4, contact c, spring S,
line 5, dial X and back to the battery. The magnet D is now energised and holds
When however
the weight C and lever c¹ in the position shown in the drawing.
the pendulum has travelled a little further, the driving lever c² is arrested by the
hook e', the circuit above described is broken at c', and the driving lever c¹ falls
upon the pendulum, thus closing the circuit from the battery through line 6;
magnet D', line 7 contact c³ spring S line 5, dial X and back to battery.
Magnet D now re-sets weight C¹ with its driving lever c³ and the pendulum
continues to vibrate to the end of its arc and in returning, the driving lever C¹

page_text: exercises pressure upon the pendulum for a longer period than it had done during
the latter half of the last vibration, thus providing the impulse. The mechanism
being symmetrical the cycle of operations is the same on the other side.
If it be desired that the weight be re-set at less frequent intervals than is the
case with the above, we prefer to do so not by lengthening the pendulum but by
introducing intermediate mechanism as follows:--
Motion is imparted to the clock by means of the weight transmitting its energy
through a click and ratchet wheel, a magnet being employed to replace the weight
in such a position that it may operate upon the next tooth after it has descended a
certain distance. The circuit of the electro-magnet and its battery is closed by a
contact of the moving weight with the armature which is at rest, the electro-
magnet thus being energized, the armature transmits its energy through the
electrical contact, the circuit being broken by the sudden arrest of the said
armature against a fixed stop, no such stop being provided for the weight at that
point.
The maintenance of the pressure upon the going train during electrical winding
may be accomplished in the following manner. The ratchet wheel as described
above may be mounted loosely on the arbor connecting it with the train, a spring
being arranged between them to transmit the whole or part of the power derived
from the weight. A click is provided in connection with the ratchet wheel in
order to prevent a backward movement of the said ratchet wheel when the pressure
of the weight is relieved.
This may be described with reference to Figure 2, in which A a is the escape-
ment driving the pendulum B. The wheel b (which gears with the 'scape wheel A)
and the ratchet wheel c are mounted on the same arbor 6. One or other of these
wheels is loose upon the arbor and is connected therewith. by means of a spring
only. The click 62 pivoted at 3 prevents a backward movement of the ratchet
wheel c. C is a weight on a bell crank lever C2, centered at which lever may
be rigid or may take the form of a spring. The arm C³ of this lever is provided
with a suitable 'electrical contact surface. The weight C communicates its down-
ward thrust to the ratchet wheel c through the medium of the click c. D is an
electro-magnet having an armature d pivoted at d¹ and provided with a contact
screw d². This armature is limited at each extremity of its stroke by the
stops d³d, and is provided with a resistance spring d³. The movement of the
lever C on its pivot is also limited by the armature contact screw d² and the stop c
The contact is in electrical connection with the clock frame while the contact d
is in electrical connection with the coils of the magnet D. This magnet D with
its armature d and stop d³ is electrically insulated from the frame by insulators D³.
The circuit through the battery and magnet D is therefore only complete when
contact touches contact d².
The action of the apparatus is as follows:-
When the pendulum is started, the weighted lever C2 in its descent causes the
contact piece c³ to approach the contact screw d² thereby closing the electrical
circuit of the magnet D and causing the armatured to be attracted and brought to
rest against the stop carrying the lever C2 along with it; but as no such stop is
provided for the lever C³ at that point the driven portion of the contact, that is
the lever C2 still continues its motion while the driving portion, or the armature,
is carried back to its normal position by the spring d³. It will be understood that
during the operation of electrical winding as above described the spring between
the wheels bc is maintaining the normal pressure upon the escapement.
If desired the electrical driving movement as above described may be in part
duplicated and arranged so that one weight or spring exercises its force upon
the escapement at the moment of replacement of the other. This may be described
with reference to Figure 3 in which the-weight C, click c; lever C2 arm C³,
magnet D and armature-d constitute the driving mechanism operating wheel b and
escapement A a, as shown in Figure 2.
The similar parts, weight C', click c', lever C₁ arm C³, maguet D' and

page_text: armature d' constitute a duplicate driving mechanism also operating wheel b, the
two devices working alternately and so keeping a continual force upon the
escapement.
We have so far described instruments in which the energy for driving
the pendulum or balance wheel has been stored in a weight free to fall, but it must
be understood that our invention is equally applicable to instruments in which
the energy is stored in a spring in tension. Now a spring does not possess the-
qualities of a weight with regard to inertia and momentum and it will be observed.
that the breaking of the contact above described is to some extent assisted by the
momentum of its driven portion. In order that this assistance may not be lost.
when it is desired that the power be stored in a spring, we either retain the
weight Cand counterbalance it or we provide a flywheel moving on the same arbor.
or geared thereto. This may be described with reference to Figure 4, which
shows the winding apparatus as applied to a portable time piece in which the
balance wheel scape wheel 4th, 3rd and centre wheel are of ordinary construction..
C' is a fly wheel centered at 6' having a pinion on its arbor gearing with rack 6
at the extreme end of lever C2. Spring D* provides the turning force. Magnet D,.
armature d arm C2, click C etcetera operate as in Figure 2.
This our invention also relates to a contact one moving part of which is driven
against a spring or weight by a ratchet wheel or its equivalent upon the train, through
the medium of a link. This link is so arranged as to be knocked out of engagement
with its driving tooth at the completion of the stroke of the armature of the electro
magnet employed to wind the clock. This may be described with reference to Figure 5,
in which the escapement A a, pendulum B, wheel b, driving disc c with click 62.
and magnet D with armature d are the same as shown in Figure 2. is a wheel!
fixed upon the arbor 61 in rigid connection with the wheel b. The driving disc c
is loose on the arbor b¹ and connected therewith by a spring. E is a rod pivoted
on the armature at e² carrying a link e adapted to engage in the teeth of the
wheel and having at its extreme end a contact spring El adapted to close the
circuit of the electromagnet D by its contact with the insulated pillar F..
The movement of rod E and link 3 is guided by the banking pins c and ed. e' is a.
pawl engaging in the teeth of the wheel c.
The action of the apparatus is as follows:-
When the pendulum is started wheels bb gradually rotate and cause the
rod E E' to approach the pillar F and touch the same thereby closing the circuit.
The magnet D attracts its armature d which, rotates the wheel c through the..
pawl to the extent of one tooth. The rod EE is simultaneously moved
towards E and at the same time is forced upwards by the banking pin which
acts upon the inclined surface of link 3. Said link is thus liberated from the
tooth by which it was driven just after click 62 has fallen into the next tooth. The
rod E E' now falls against banking pin c and the electrical circuit is broken,
the spring d causing the armature to return to its normal position.
It will be understood that we have so far referred to a single electric clock..
This clock we term a "controller" and it is obvious that it need not be provided
with indicating hands. When it is desired that time should be indicated in
additional places the use of similar clocks with pendulums or balance wheels in.
such places may be dispensed with.
For this purpose we employ novel methods of propelling and locking the fingers-
on subsidiary dials or other instruments by means of the intermittent electric
current governed by the contact in the "controller" as above described. One-
uch method consists of toothed wheels driven by pallets entering against the
nclined surfaces of their teeth; the pallets being arranged so that by springs or
imilar devices the one may gain upon the other during a portion of the cycle of
perations; or the wheels may be so arranged that the wheel being driven by one
allet may be caused to gain upon the wheel being released by the opposite pallet,
he object of either of the above arrangements being to carry the bands through
hat portion of their cycle which would otherwise be a dead centre. This part of

page_text: the invention may be described with reference to Figures 6 to 10 in which similar
letters indicate similar parts.
In reference first to Figures 6, and 6^, the former showing a dial movement in
which the intermittent current governed by a controller herein before described
causes the electro-magnet D to attract the armature d said armature being pivoted
at d and having an anchor a with pallets a' a' attached at its rear end.
A is a
scape wheel mounted on the arbor , the teeth of which engage the pallets a¹ a².
A pinion upon the arbor 1 gears with the centre wheel b connected with the hands
in the usual way. The pallets a¹ a² are attached to the anchor a, a¹ being in rigid
connection therewith and a² attached by means of the spring arm a³ and abutting
against the stop screw a' as shown in Figure 64 which is a detail drawing to show
the way in which the pallet a² is attached to the anchor a. The pallet a is also
provided with a knee joint at a and spring a to keep it normally closed. The
action is as follows:-' When the armature is attracted the pallet a recedes from
the scape wheel A, and at the same time the pallet a² approaches it and enters
against the inclined surface of a tooth. As pallet a' has not yet unlocked wheel A,
spring arm a will be compressed. When the pallet a' has liberated the scape wheel
the spring a³ will turn it forward a short distance and the return of the armature
will cause pallet a¹ to enter the next tooth and drive the scape wheel a further
distance so that the whole displacement of the wheel is equal to the pitch. It
will be observed that the knee joint as is necessary to enable pallet a² to escape
from wheel A during the return stroke of the armature.
In Figure 7 a magnet D' is employed instead of the spring a³ for the purpose of
making one pallet gain upon the other with a view to carrying the hands through
that portion of their cycle which would otherwise be a dead centre.
The construction is as follows:-
The pallet a is pivoted upon armature Fat f. Said armature is hinged at fl
and is limited in its outward stroke by stop 2. n is a spring normally bearing
against contact screw n¹ in electrical connection with magnet D but said spring
being in the path of armature F will break contact with screw n¹ wherever the
armature is attracted. Pallet a¹ is rigidly fixed to armature d and both armatures
are held in their normal positions by spring F¹. The action is as follows:-The
intermittent current energizes magnets D, D' simultaneously, thus withdrawing
pallet a¹ and turning wheel A by pallet a². Armature F then. engages spring n
and breaks circuit of magnet D thus allowing pallet a¹ to lock wheel A before
pallet a returns.
In Figure 8 the pallets a¹ a² are separately centered at at a on each side of the
anchor a and are held inwards by the spring a³, the anchor a by means of pro-
jections 1, 2, 3, 4, being adapted to lift one pallet out of engagement with the
wheel A and force the other one into engagement with said wheel at every
vibration of the armature. The pallets a a² will thus gain one upon the other
radially and so turn wheel A through that part of its cycle which would otherwise
be a dead centre.
In Figure 9 the pallets a¹ a² are fixed upon the lever a pivoted upon armature d
at a and having a slot at its rear end g. g' is a link centered preferably spring
tight at 2 and supporting lever a by a pin running freely in slot g. When the
armature d is attracted, the pallet a will release wheel A, and pallet a² will enter
the wheel in the same direction until the end of the slot meets the pin on link g²,
engaging with it, the pallet a² will then change the direction of its movement and
will gain upon pallet a¹ circumferentially, thus moving wheel A through that part
of its cycle which would otherwise be a dead centre.
In Figure 10 two wheels A c are employed, connected by the springs a³ and a
attached to wheel A which engage the pillar g³ fixed in wheel c. The pallets a¹ a²
are rigidly fixed to anchor a attached to armature d. The attraction of the
armature drives wheel A half a tooth and the return of the armature drives wheel c
half a tooth.
In another method the clock is constructed on ordinary lines in that it is driveṇ

page_text: by a spring or weight and controlled by an escapement, the winding of the spring
or weight and the action of the escapement being simultaneously effected by means
of an electro magnet in the circuit as above described; or the escapement may
be combined with the pawl which connects the spring or weight to the wheel work.
This may be described with reference to Figure 11, which shows a dial move-
ment. In this the intermittent current governed by the controller hereinbefore
described causes the electro-magnet D to attract the armature d, said armature
being pivoted at d¹ and having an anchor a (with pallets a¹) attached at its rear
end, and a driving. pawl c' pivoted upon one of its arms. In this figure, A is a
'scape wheel, the teeth of which engage the pallets a¹. C is a ratchet wheel, the
teeth of which are adapted to be engaged by the driving pawl c¹.
The 'scape
wheel A and the ratchet wheel C are mounted on the same arbor . One or other
of these wheels is loose upon the arbor and is connected therewith by means of the
spring only. A pinion upon the arbor b' gears with the centre wheel b connected
with the hands in the usual way. The click pivoted at 63 and held upwards by
the spring prevents a backward movement of the driving wheel.
It will be obvious that when the armature is attracted and released it will wind
one tooth of the driving wheel C, at the same time allowing the 'scape wheel A to
progress one tooth.
It will be readily understood that in the complete system of electrical clocks as
above described convenient switches may be provided by which the hands upon the
dials in the circuit may be set on or put back without in any way interfering with
the vibrations of the pendulum.
To set the clocks forward a key is provided to operate the circuit of the dials
and their battery. To set the clocks back, a two way switch is employed, the
movement of which disconnects the dials and their battery from the controller and
its battery until replaced into its normal position.
This switch may be so arranged that it is automatically replaced after any
desired interval of time. This may be accomplished by the use of a rotating
ratchet wheel and a lever furnished with a click. The switch is held in its normal
position by the lever and when the clocks are to be set back the lever is drawn the
desired distance away from the switch the click passing over the teeth of the
ratchet wheel, so that in due time the said lever returns and replaces the switch.
This may be described with reference to Figure 12, in which the circuit of the
dials DDD may be disconnected from the pendulum, or controller, B, for any
desired length of time by a backward movement of the hand D2 upon an instrument
which we will call a "controller dial" operated by the magnet D' shown diagram-
matically. In the drawing the lever H and the contact points 9 g form a two
way switch which is normally in such a position that the circuit is from 9 through
the controller B, the dial magnet D¹, the lever H, contact 9, dials DDD and
back to the battery at g'. When the switch H is reversed the circuit is from gº
through B D' H and 9 returning to the battery at g³.
D' represents the coils of the magnet which operates the minute hand D2 by
means of any known form of dial movement or those described with reference to
Figures 6 to 11. The band D2 is spring tight upon its arbor and has a ratchet
wheel in rigid connection with it. 3 is a similar ratchet wheel in rigid
connection with the dial movement. h is a lever pivoted upon the centre wheel
arbor and held by the spring against the short arm of the lever H. ¹² are
clicks pivoted upon the lever and adapted to engage in the teeth of the ratchet
wheels and h³.
The mode of action is as follows:-
When the hand D2 is turned backwards lever is raised by means of the ratchet
wheel and click against the spring, causing the switch H to cut the
dials D D D and their battery cut of circuit, click * in the meantime passing over
the teeth of the wheel 3 and preventing the sudden return of the hand D². The
progress of the hand, though assisted by the spring through the medium of
wheel is controlled by the dial movement D' in the usual manner. When the

page_text: band has reached the position which it occupied before being moved backwards the
switch H is reversed.
If it is desired that sufficient latitude be provided to allow of the hands being
turned back several hours, the lever h is mounted on a screw thread so that the
number of hours may be recorded by the lateral position of the lever along the
screw. This arrangement ensures that the lever h passes clear of the contact
lever H at the completion of the first revolution backwards.
This device may be more clearly shown with reference to Figure 13, in which
.h is mounted on the screw ' by means of the collar 8. is a detent carrying the
-clicks and is connected to lever h by the runner passing through a clearance
hole in said lever h. is a ratchet wheel in rigid connection with the minute hand
as described in Figure 12, and 3 is a ratchet wheel rigidly connected to the
arbor 10 which is driven by any known form of dial movement or those described
with reference to Figures 6 to 11. The spring may be connected to the collar ³
by a piece of chain or similar flexible material.
Upon commencing to set back the hands of the governing dial several hours, the
action of the apparatus is as follows:-
Lever h leaves contact lever H and rotates upon the screw motion being
transmitted to it from the hand by click detent with its runner . When
the hands have been moved back as far as desired click 2 prevents their return by
engaging ratchet ³, which gradually rotates with the dial movement above
alluded to. Thus it will be seen that if the hands for instance have been turned
back 3 hours the wheel 3 will not allow lever to replace the switch H until it
has made 3 revolutions.
The striking gear is arranged as follows:-
A dividing plate may be driven by any electro-magnetic device, preferably that
described above, against an air or other resistance which may take the usual form
of a fan or fly, the train being locked on the dividing plate alone by a detent
operated by an electro-magnet energised momentarily at the hours or hours and
quarters. In some cases it is advisable to provide the detent with a spring which
causes it to move in the reverse direction to the dividing plate at the moment of
disengagement.
This may be described with reference to Figure 14 which illustrates the method
we adopt for controlling single stroke electric bells at the hours only. n² is an
armature lever pivoted at n³ in the field of the magnet M, said armature being
limited in its stroke by stop pin n' and contact piece n³ n is a lever pivoted upon
the armature at n' and limited in its stroke by stop pin n³ and contact piece n°.
1 is a snail or cam in rigid connection with a minute hand of a clock in any part of
the system adapted to raise lever n into contact with n at each hour; the
magnet M will then withdraw the lever n but will maintain the contact at n°.
The magnet D, armature d, ratchet wheel c of 78 teeth on arbor 1, weighted
lever C, with arm C³ form the driving gear as described with reference to
Figure 2. This or any suitable method of propulsion is employed to drive the
dividing plate L on arbor 6. L³ is a fan or fly geared to arbor 6 through the
medium of wheels L₁ L' and their pinions.
Detent m spring mounted on armature m², centred at m³ in the field of magnet M¹
engages dividing plate L. m is a lever in rigid connection with armature m2 and
adapted to lift spring m from contact piece m when magnet M' is energised.
N N' are single stroke electric bells in the circuit of magnet D.
The action of the apparatus is as follows:--
The circuit of magnet M is closed at the hour by means of wheel I as above
described. The circuit of magnet M¹ is now closed at and. and operates.the
armature m² breaking the circuit at mo. The dividing plate L being now liberated
by detent m¹ will be driven forward by weight C against the fan L³, and the bell
circuit will be closed at d² as often as is required, the number of strokes being
dependent upon the extent of the travel of dividing wheel L passed detent m
between the hour notches on its periphery.

page_text: When the hourly-revolving wheel is available adjacent to the striking mechanism,
we modify the arrangement as shown in Figure 15. Lever n is pivoted on
armature d and is in electrical connection with the dividing plate L being provided
with insulated collar n¹º.
Dividing plate L has insulated sections upon its periphery instead of notches,
and detent m² takes the form of a contact spring bearing upon it, said contact
spring being in electrical connection with contact piece n°.
The action is as follows:-
At the hour, the wheel I carries the lever n into contact with no and thus closes
the circuit of bells N N¹ and magnet D through contact d2 which is normally
closed. The bells ring and the weight C is reset simultaneously. The weight
then drives the dividing plate L against fan L³ and the operation repeats itself
until spring m² encounters an insulated section of dividing plate when the circuit is
broken. To synchronise a series of these clocks they are connected to a line upon
which an electrical pressure is exerted at certain periods determined by the standard
time-piece; in the event of the clock being fast or slow a circuit is formed from the
line through a commutator and one or other of two electro-magnets so arranged as
to increase or diminish the free length of the pendulum or its equivalent.
Referring to Figure 16 which shows the details of the synchronising mechanism.
In this B is a suspension spring supporting the pendulum rod B of a controller
which it is desired to synchronise, and which will in future be referred
to as a "subcontroller," B* is a frame capable of movement in a vertical direction,
at the lower end of this frame are two jaws which fit against the suspension spring
and by their position determine the free length of the pendulum B. D'D³ are
two electro-magnets operating upon the armature d which is centred at d¹ and
carries the forked extension piece d' engaging with a pin upon the sliding frame B².
A commutator J mounted upon the wheel in the going circuit of the pendulum
to be synchronised, that is to say either mechanically or electrically connected with
the pendulum B is so arranged that if the pendulum to be synchronised is either
fast or slow, the periodic current from the master clock energises one or other of
the electro-magnets D² D³.
The action of the apparatus is as follows
-
Suppose the sub-controller to be say a minute slow at the time of synchronisa-
tion, then commutator J will complete a circuit from the line through magnet D³
enabling the synchronising current to energise it, attract the armature d and thus
shorten the effective length of the pendulum. This will put a gaining rate upon
the clock and the commutator will eventually reach such a position that the
synchronising current will energise the magnet D' and so lengthen the pendulum.
It will be understood that the length of pendulum required for absolutely correct
time keeping is somewhere between the limits of variation allowed by the sliding
frame B².
We
Turret clocks may be controlled by the apparatus above described whether the
said turret clocks are driven by weights or by hydraulic or electric power.
will describe our apparatus as being electrically driven from a local circuit though
it will be understood that we arrange the same action when making use of weights
or water as a motive power; detents or valves and barrels or cylinders being
substituted for the parts here described as switches and electro magnets.
One part of a circular insulated gap switch is driven by a "dial" movement from
any time circuit governed by a controller as above described, the other portion of
the said switch being turned by the centre wheel of the secondary mechanism. This
gap switch closes a local circuit through a motor, this circuit being broken from a part
of the going train or by the gap switch itself. In the case of a turret clock of unusual
size, a relay may be employed.
This may be described with reference to Figure 17 in which R is a motor driven
from a local circuit, its speed being reduced by the gear wheels R¹ R² R³ and R',
the last named being in connection with the minute hand of the dial on arbor r.
D

page_text: 6 is a wheel mounted loosely upon arbor and revolved hourly by means of pawl 2º¹
click armature d and magnet D or by means of any suitable dial movement such
as those described with reference to Figures 6 to 11 in the time circuit of any
controller. is an arm mounted loosely on arbor r in electrical connection with
motor R and connected with wheel 6 by means of spring being held in the
position shown by pin fixed in wheel b. 6 is a contact piece mounted on
wheel R and in electrical connection with motor R.
The action of the, apparatus is as follows-
The intermittent current from the controller will revolve wheel 6 by means of
the pawl and ratchet movement shown, and the switch 3 will be closed. The
motor R will then revolve until the contact on wheel R has been carried out of
the range of arm r³.
1
By this arrangement it will be seen that not only is the train governed under
normal conditions by the dial movement and the gap switch, but in case of a
temporary failure of the local or power circuit, synchronisation is re-established
between the primary time circuit and the hands of the turret clock when the
failure of the local circuit is rectified..
In order to avoid the too constant starting and stopping of the motor, it is
sometimes convenient to adjust its speed only slightly in excess of that required to
revolve wheel R* hourly and insert a rheostat in the motor armature circuit to be
mechanically operated by a slight movement of contact piece so that upon the
advance of the train a certain distance electrical resistance is thrown into the motor
armature circuit by the separation of the pin and arm ³ and thus the motor R
is slowed down; it may be considerably but is not absolutely stopped. Such a
rheostat may consist for example of a series of carbon plates placed between the
pin 7 and arm or so connected with these parts that as the distance between said
pin and arm increases the plates are less pressed together and their resistance
therefore increased.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In an electric apparatus for driving a pendulum (in which the power required
to maintain its swing is mechanically transmitted through the surfaces of the
contact) the use of two gravity pieces or arms so arranged as to be alternately
raised or operated by two electro magnets, the contacts for the control of which
are made on the pendulum itself by the said gravity arms, substantially as
described.
2. In an electric clock, the combination of a going train, a winding device
actuating the same, an electro magnet capable of periodically winding up the
driving device on completion of the circuit, a vibrating armature to said electro
magnet and a contact device formed of a moving part of the driving device and the
said armature whereby when the driving device has run down to a given extent it
shall make contact with the armature and thus close the circuit and allow the
electro magnet to wind or set up the winding device.
3. In an electric clock the combination of an escapement device A, a driving
wheel C, oscillating lever c having pawl c¹ and contact arm c³, the electro magnet
and armatured with an electric circuit controlling the magnet and made whenever
the lever arm c³ comes in contact with the armature whereby whenever the arm
is caused to descend sufficiently by the weight Ca contact is made, the magnet
draws in the armature which throws up the lever, thus rewinding the clock.
4. An electric clock in which the driving device is automatically wound up by
an electro magnet in part duplicated and arranged so that one weight exercises its
force upon the escapement at the moment of replacement of the other substantially
as and for the purposes described.
5. An electric clock in which the driving device is automatically wound up by

page_text: au electro magnet (as described with reference to Figure 2) and in which the
power required to drive it is stored in a spring instead of in a weight, the use of a
geared fly wheel substantially as and for the purposes described.
6. In an electric clock in which the driving device is automatically wound up by
5 an electro magnet, a contact, one moving part of which is driven against a spring
by a ratchet wheel, through the medium of a link, which link is knocked out of
engagement at the completion of the stroke of the armature of the electro magnet
employed to wind the clock substantially as described and shown with reference to
Figure 5.
7. In an electric clock in which the contact link is raised by the going train,
forming said link with a wedge shaped surface and in combination therewith a
pin C or its equivalent substantially as and for the purposes described.
8. In a clock dial apparatus in which an intermittent electric current is employed
to revolve the hands, a scape-wheel operated upon by two pallets, one of which is
spring mounted upon a knee joint so that it may gain upon the other circum-
ferentially during the cycle of its movement substantially as and for the purposes
described.
9. In a clock dial apparatus in which an intermittent current is employed to
revolve the hands, an auxiliary magnet and armature as and for the purpose
described.
10. In a clock dial apparatus in which an intermittent current is employed to
revolve the hands an anchor adapted to lift one pallet out of engagement with the
driving wheel and to force the other into engagement with said wheel alternately
in such a manner that they may gain one upon the other radially substantially as
and for the purposes described.
11. In a clock dial apparatus in which an intermittent electric current is
employed to revolve the hands, a scape wheel with pallets for driving the same,
said pallets being mounted upon a lever hinged to the armature of the electro-
magnet at one end and slotted upon a radius arm at the other end, so that one
pallet may change the direction of its movement and gain upon the other
circumferentially as and for the purpose described.
12. In a clock dial apparatus in which an intermittent electric current is
employed to revolve the hands, an anchor with two pallets rigidly attached thereto
and two wheels coupled together by springs so arranged that each paliet drives its
wheel to a given extent before the other wheel is unlocked substantially as and for
the purpose described.
13. In a clock dial apparatus an electro-magnetic device actuating the escape-
ment and the winding device simultaneously, whereby at each stroke of the
escapement the apparatus is wound up to the exact extent to which it would be run
down by the movement of the escapement.
14. The combination of the electro-magnet D, the armature d, the anchor a,
carried thereby, the pawl e' carried by mechanism da, and actuating the winding
wheel C, whereby the clockwork is wound up simultaneously with the action of the
escapement, substantially as described in Figure 11.
15. The combination of the electro magnet D, the vibrating armature lever d,
the anchor a, the pawl c¹ driving wheel C, and the spring c³ connected at its ends
to the arbor of the escape wheel, and driving wheel C respectively.
16. The method of setting back the time of a circuit of electric clocks which
consists in connecting the hand of one dial with a contact making device in such
manner that by putting back the said hand the contact device shall cut out the
circuit from the other clocks until its dial has returned into synchronisation with
he others.
17. In an electric clock installation the combination in a single dial of a contact
levice actuated by the backward movement of the hand in the main circuit
hereby if the hand of this governing dial be set back a given amount the circuit
hrough the remaining dials is cut off until the governing dial has again arrived at
he point of synchronisation with the other dials.

page_text: 18. The combination of the hand D2, the wheel h, the lever h having a pawl
device holding wheel from turning in one, direction, the contact lever H with
the two circuits, the main circuit 96, B, D, H. 9', D, D, D, g' and the extra
circuit 9, B, D, H, 9ª 9º.
19. The combination of the hand D2, the wheels h and h³, lever h carrying
pawls and h², the contact lever H and the main circuit and the extra circuit
substantially as described.
20. In a governing dial the mechanism substantially as described with reference
to Figure 13 for allowing the hands to be turned back to the extent of several
revolutions.
21. In electric clocks, a striking device consisting of a train of wheels, a
resistance such as a fan, and a ratchet on the slowest member of that train, a
dividing plate having spaces proportionate to the numbers 1 to 12 inclusive, with
pawl catching into the dividing plate, a rotating projection synchronously connected
with the minute hand and adapted to liberate said pawl by means of an electro-
magnet and a rewinding electro magnetic device and contact brought into action by
the partial running down of the said motive device.
22. In electric clocks, a striking device consisting of a train of wheels, a
resistance such as a fan and a ratchet -on the slowest member of that train, a
dividing plate having insulated sections proportionate to the Nos. 1 to 12 inclusive,
with a contact brush resting upon dividing plate, a rotating projection synchronously
connected with the minute hand and adapted to close the circuit of the rewinding
electro magnetic device.
23. The combination with the suspension spring of an electric clock pendulum
of two electro magnets having their poles substantially opposite each other and
close together, a vibrating armature between the two magnets and connected to
this armature, a frame terminating in a fork on each side of the suspension spring,
whereby according as the armature is lifted up or down by the respective magnet
the pendulum is made to gain or lose.
24. The method of synchronising electric clocks which consists in causing a
synchronising current independent of the ordinary working current to impart to
the pendulum a gaining or losing rate substantially as described.
25. In a synchronising device for electric clocks the combination of the electro
magnets D2 D3, the vibrating lever armature d d', the sliding frame R³, the
suspension spring B' and the pendulum B substantially as described.
26. The combination of an electro-motor in a local circuit with an electric clock
dial apparatus adapted to revolve by a step by step, movement in a time circuit, in
which the motor operates the hands of a turret clock by the progression of the
dial movement in such a manner that in the event of temporary failure of the
motor circuit synchronisation is re-established between the primary time circuit
and the hands of the turret clock when the failure of the local circuit is rectified
substantially as described.
Dated this 22nd day of October 1905
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Birmingham, and London, Patent Agents.