Improvements in Electric Clocks.
Year: 1890

page_text: Date of Application, 10th Oct., 1890-Accepted, 15th Nov., 1890
COMPLETE SPECIFICATION.
Improvements in Electric Clocks.
I, DAVID FAIRGRIEVE of 26 Narrowgate, Alnwick in the County of Northumber-
land, Watchmaker and Jeweller, 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:-
This invention relates to that class of electric clocks known as sympathetic clocks
in which one primary clock conveys absolutely isochronous movement by means of
magneto electric currents, to any number of affiliated clocks, inserted in the circuit
of the battery at any distance from the primary clock.
The chief features characteristic of my said invention consist in providing means
or apparatus for :-firstly, driving the pendulum of the primary clock; secondly,
transmitting the electric current from the primary clock to the secondary clocks in
circuit; and, thirdly, for actuating the striking mechanism.
In the accompanying drawings
Figure 1 is the regulating arrangement for pendulum and means for transmitting
the driving current,
Figure 2 is the primary clock and striking apparatus for transmitting the striking
current to the secondary clock or clocks.
Figure 3 is the secondary clock.
Figure 4 is a modification of the regulating arrangement for primary clocks shown
in Figure 1.
Figure is the striking apparatus of the secondary clock worked by a current
transinitted direct from the pendulum of the primary clock Figure 4.
In carrying out my invention the pendulum A is suspended by an ordinary spring
and provided at its upper end with an arm or lever a'. Two weighted contact levers
or rods B, B1, are suspended, one on each side of the pendulum A, from pivots b¹
and rest upon stops. The lower weighted ends of the levers are fitted with platinum
points 3. The lower weighted ends of the levers are fitted with platinum
points. The pendulum, as it oscillates, slightly raises each lever B, B1, thus making
and breaking contact alternately. A plate is adapted to the upper end of one of
the pivotted levers or rods B to which a spring is secured, having a right angled
extension and bevelled nose piece c³. C is an electro magnet and Can armature,
weighted to the desired extent to serve as a gravity piece, which is pivotted at c; the
end of the armature, which consists of a fine metal rod, being prolonged and bent up
at right angles, the hooked extremity e resting on the nosepiece e of the spring .
Z, Figure 1, is the battery. The electric current passes from Z to the terminal c
above the pendulum A. It is led through the latter and from thence upwards
through each lever or rod B, B'. The current which passes through the lever B and
from the binding screw c along the wire is the "striking" current, whilst that
which passes through the lever B₁, binding screw and magnet C by way of the
wire a is the "driving" current. The wire c acts as a common return for both
currents. On being started, and swung to the left, the pendulum A comes in contact
with the lever or rod B, which, together with the plate 6' and spring 6' is slightly
raised, so that the hooked extremity 2 of the weighted armature C¹ disengages with
the nose piece of the spring ; the weighted armature then descends and rests
upon the projecting arm a¹ so as to give impetus to the pendulum A during the first
arc of its oscillation when returning in the opposite direction.
After passing the vertical, the pendulum makes contact with the opposite lever or
rod B', the electric circuit is thus completed and the armature C attracted to the
magnet C, whilst the hooked extremity presses against, and, after passing rests upon
the nose-piece c³ of the spring b. The pendulum is thus caused to vibrate continuously

page_text: without variation until the strength of the battery becomes insufficient to raise the
weighted armature.
In Figure 2, d, d', d, d³, represent respectively the escapement wheel, third wheel,
centre wheel, and minute wheel of an ordinary clock train of wheels. When the
circuit of the driving current is completed by the pendulum A coming in contact with
the point of the lever or rod B₁ the magnet D of the primary clock attracts the
armature D', the pawl d' of the latter moving the escapement wheel d for half a tooth,
after which the bevelled end of the spring catch d completes the movement. The
vibration of the pendulum is thus transmitted through the primary clock to the
sympathetic or secondary clock at Figure 3. The magnet E armature E' and train of
wheels of the secondary clock, Figure 3, are thus put in synchronous action with
those of the primary or driving clock. The driving current may be put in circuit
with any number of secondary clocks, the current returning to the battery Z from
the magnet of the last secondary clock in circuit along the wire c from the connecting
post y.
"
The "striking" current, which is open once every hour, passes from the lever or
rod B along the wire b to the terminal of the contact spring e, (Figure 2,) through the
latter, and thence through the spindle e' on which are mounted the escapement and
count wheels e, e, to the terminal et attached to the metal framework. After passing
through the second magnet F of primary clock and thence through the magnet G
of secondary clock, the ". striking' current returns along the wire c from the
terminal y to the battery Z. The count wheel e consists of a drum or cylinder which
rotates with the escapement wheel e. Recesses are formed at varying distances in
the circumference of the count wheel e³, in which strips of insulating material aro
inserted, the recesses corresponding to the notches in the count wheels of ordinary
striking clocks. The end of the contact spring e presses upon the periphery of the
count wheel. When the pin e on the minute wheel d³ approaches the hour it
depresses the end of the pivotted lever e, the pawl of which slightly rotates the
escapement wheel e; the circuit is thus completed and the magnet F attracts the
pivotted armature F'. The pawl of the latter, assisted by the spring catch do, thus
rotates the escapement wheel one tooth at each swing of the pendulum. The hammer f
of the bell is adapted to the armature G' of the magnet G of the secondary clock
Figure 3, and is caused to strike by the armature G' which is attracted simultaneously
with the armature F of the primary clock, the number of strokes being governed by
the exposed uninsulated surface of the count wheel e².
Instead of being detached, the apparatus shown at Figure 2 may be adapted to
work with the pendulum Figure 1, in which case the arinature D' and magnet. D,
Figure 2, would be rendered unnecessary, the pawl d' of the armature D¹ working the
escapement wheel d direct from an extension of the armature C¹ Figure 1.
In the modified arrangement Figures 4 and 5 the pendulum A, suspended from the
knife edge c, is provided, in addition to the projecting arm a', with a catch lever a².
The latter, as the pendulum swings, presses against the upper end of the pivotted
catch 6; the horizontal nose piece c then disengages with the weighted armature C',
after which the latter is released and falls upon the projecting arm a' of the pendulum.
The armature C is again attracted to its magnet C when the pendulum swings to the
opposite side and makes contact. The driving current flows from the battery Z along
the wire a, the striking current passing from the battery Z along the wire b. The
contacts for the striking and driving currents, disposed on each side of the pendulum,
· comprise four pivotted levers or rods B, B1, B2, B3, arranged in pairs one above the
other. B₁ B³, are the contact levers for closing the "driving current circuit,
B. B2, those for closing the "striking" current circuit. The upper rods B. B' are
pivotted at a³, the lower ends being weighted and are fitted with platinum contact
points. The two lower rods B2 B3, weighted at their lower ends are pivotted at
or about their centres a. When the pendulum swings to the right, contact is made
with the lower end 63 of the upper rod B which presses against the upper end of the
lower rod B2, thus sending the "striking" current along the wire to the striking
apparatus, which according to this modification, is stationed with the secondary clock.
"

page_text: The "striking" current ceases to flow when the pendulum swings to the left and
coming in contact with the lower end of the upper rod B' presses the latter against the
upper end of the lower rod thus closing the circuit and sending the driving current
along the wire a.
In Figure 5, is the escapement wheel the count wheel, et the pin on the
minute wheel d³; f' the bell, the hammer attached at one end to the pivotted rod g
carrying the armature G' of the magnet G. e is the contact spring the point of
which bears on the count wheel e². As soon as the pin e' of the minute wheel d³,
reaches the hour it raises one end of an arm 2, projecting from the bell hammer f, and
depresses one end of the pivotted rod y so that the pawl g' on the opposite end
slightly rotates the escapement wheel and count wheel e² a sufficient distance to
allow of the point of the contact spring e making contact, whereupon the current flows
through the magnet G and attracts the armature G'. The hour is thus struck at each
swing of the pendulum, the number of strokes being governed by the count wheel e²,
as previously described with reference to Figure 2.
To simplify the working of the escapements the pawls d may be dispensed with,
in which case the ends of the armatures or levers would be bevelled, the teeth of the
wheels being shaped accordingly.
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
clain is
First. The improvements in electric clocks substantially as herein set forth.
Second. In an electric clock the combination with the pendulum A of two weighted
pivotted levers or rods B, B', for alternately making and breaking contact substan-
tially as described herein and shown at Figure 1.
Third. The combination with an electric clock of a weighted armature or gravity
piece C and means for automatically raising and afterwards releasing same in order
to impart motion to the pendulum A substantially as herein described and shown at
Figure 1.
Fourth. The combination with an electric clock of a pendulum A weighted pivotted
contact levers B, B1, B2, B3, and means for releasing the weighted armature C, by
the motion of the pendulum substantially as and for the purposes herein set forth
and shown at Figure 4.
Fifth. The combination with an electric clock of a count wheel e² and ratchet
wheel which are started in motion by the pivotted levere and rotated at each
stroke of the pendulum by the attraction of the armature F¹ substantially as described
herein and shown at Figure 2.
Sixth. The combination with an electric clock of a count wheel e ratchet or
escapeinent wheel e³, set in motion by a pin e on the minute wheel d³; pivotted
lever carrying the bell hammer f, projecting arm f2, pawl 91, and armature G'
substantially as herein described and shown at Figure 5 and for the purposes
specified.
Seventh. The general arrangement of armatures, magnets, lovers, contacts and
connections for transmitting synochronous action from one primary clock to any
number of secondary clocks by means of electric currents substantially as herein
described and shown at Figures to 5 inclusive of the accompanying drawings.
Datal this 30th day of Santamber 1890
JAMES STEVENSON,
Gray's Inn Chambers, 20, High Holborn, London, W.C., Agent for Applicant.