Improvements in and relating to Electrically Operated Clocks.
Year: 1898

page_text: Date of Application, 19th Dec., 1898-Accepted, 19th Dec., 1899
COMPLETE SPECIFICATION.
Improvements in and relating to Electrically Operated Clocks.
I, HJALMAR EMANUEL ANDERSSON, of 97, Drottninggatan, Stockholm, in the
Kingdom of Sweden, Clock and Watch Maker, 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:-
The clockwork forming the subject of this invention operates substantially as
follows: the electric current is interrupted whenever the balance (or escapement)
wheel, situated in the path of the anchor (or pallets), completes one revolution;
when this occurs an armature operated by electro-magnets is set in motion, and its
motion is utilized in winding up a mainspring; so that the clock is kept going
reliably until the circuit is closed again and the spring once more wound up.
In order to prevent the break of the circuit, which takes place when the winding-
up is completed, from damaging the contacts arranged in the escapement, or path
of the pallets, the clock is fitted with a special current-breaker or switch which
cuts off the current before the contacts are separated. This switch offers the great
advantage that the parts thereof, which are conductors of electricity, are not
damaged by the oxidation arising from the formation of sparks. This enables the
clock to be kept going for an indefinite period of time, so long as the power of the
electrical current is maintained. Besides, the arrangement of this clock offers
the advantage of being extremely simple; which remark in particular applies to
the mainspring which, being wound up periodically and at frequent intervals, may
be very small and simple in construction. It is moreover the only mainspring
which the clockwork possesses both for the moving and striking works, the latter
being connected with and operated by the electrical armature direct.
Referring to the accompanying drawings:-
:-
Figures 1 and 2 represent the mechanism belonging to the moving (or "going")
works.
Figures 3, 4 and 5 show the mechanism devised for the striking works;
Figures 4" 6 and 7 are detail views, and
Figures 8 and 9 show the current breaker being, respectively, a vertical section
and a horizontal section of the same.
To the upper edge of the supporting frame or cage of the clockwork there are
attached two electromagnets 1 between which the swinging or oscillating arma-
ture 2 is interposed; such armature being revolvable on the spindle 5 supported
by the two bottom pieces 3 and 4. Of the two spindles 6 and 7, similarly sup-
ported, one carries the escape wheel 8 of the escapement, and the other, the anchor
or pallets 9. The escapement wheel carries a pin 10 in the path of which there
are located the ends of two wire-springs 11 branching off from the spindle 7.
These springs are secured to a sleeve or socket 12 secured to the spindle 7 and
properly insulated. The electrical current generated in the battery in one direc-
tion, passes through a wire conductor 14, to one of the magnets 1, and hence
through the wire 15, to the other magnet 1; then, through the wire 16, to the
current breaker or cut-off switch 17, and lastly through the wire 18 into the

page_text: clockwork. In the opposite direction, starting from the battery 13,-the current
passes through the conductor 19 to the insulated sleeve or socket 12. From this
diagrammatic exposition of the course taken by the current it will be understood
that, when the pin 10 of the escapement wheel 8, and the wire springs 11, come
in contact with each other, the electrical circuit is closed, whereby a partial
revolution of the armature 2 and spindle or arbour 5 in the direction of the arrow a
Figure 1 takes place. As before mentioned, the effect of this is that the main-
spring is compressed; this being effected by the following arrangement:
The mainspring 20 Figures 2 and 7 is coiled upon a barrel 21, loose upon the
arbour 5, and one end of it is attached to the said barrel 21 while the other end is
connected with the toothed wheel 22 loose upon the arbour 5 and adapted to impart
rotary motion to the escapement wheel. Upon the part of the arbour 5 enclosed
within the barrel 21, a small disc 23, resting against a projection of the arbour,
is mounted; and between this disc and the barrel is arranged a helical spring 24
the power of which is sufficient to lock the barrel to the arbour by frictional
resistance during the winding of the main spring 20, which frictional resistance
is, however overcome whenever said main spring is wound up to excess, thus
allowing the arbour to revolve independently of the said barrel so that a breakage
of the main spring is effectually guarded against.
In order, however, to prevent any possible backward movement of the barrel,
when the spring 20 is compressed to the normal degree, there is provided at one end
of the barrel or drum a ratchet wheel 25 (see Figure 7) which engages with a pawl
or click 26. The arbour 5 is carried round by the armature 2 through the medium
of a spring click 27, secured to the said armature, which operates in conjunction
with a ratchet wheel 28 secured to the arbour 5 (see Figures 2 and 7). The back-
ward motion of the wheel 28 and arbour 5 is prevented, after the spring 20 has
been compressed, by a click 29 secured to the bottom plate 3 and also engaging
with the said ratchet wheel 28. The cut-off switch 17, the construction and opera-
tion of which will be presently described, has for its conducting element a column
of mercury which, when the circuit is to be interrupted, is cut off by means of a
revolvable insulating disc 30 (Figure 3).
The disc is secured to and revolves on a vertical spindle 31 (Figure 4) to the
upper end of which there is secured a fork between the projecting legs or prongs 32
of which oscillates an arm attached to the armature 2. Whenever the armature
has been turned in one or the other direction, the arm 33 will actuate either one
on the other of the prongs 32 and open or close the circuit as the case may be.
The current is cut off when the arm is in the position opposite to that shown in
Figure 1. With regard to the contact device 10, 11, of the anchor escapement,
the arrangement is such, that the current is cut off just before the contacts are
moved apart.
The moment the circuit is interrupted, the armature 2 is acted upon by the
counterpoise weights 34, and by the time the movement is completed, the arm 33
will have resumed the position indicated in Figure 1 i.c. operated the other
prong 32 of the fork, so that the circuit is closed again to repeat its action the
moment contact takes place between the pieces 10 and 11. To render the motion
of the arm 33 slow and uniform, a toothed segment 37 is furthermore provided,
it being rigidly secured to the armature and adapted to operate a fly 38.
A most important part of the clockwork is that, by which the pin 10 and
wire-springs I are prevented from interfering with the going clock when they
meet. As illustrated in Figure 6 the anchor escapement is of the construction in
which the pallets of the anchor 9 are in the shape of an arc of a circle, the centre
of which is formed by the spindle 7 of the anchor. The operation of such an
anchor is well known to be this: When the tooth 361 of the escapement wheel,
for example, is released by the pallet 351 of the anchor, the tooth 361 comes to rest
upon the arc-shaped inner side of the pallet 35, an effect which is produced both
when the pallet has commenced its oscillatory movement towards the centre and
when it has begun to move in the opposite direction.

page_text: It will be readily understood that inasmuch as the escape-wheel remains per-
fectly motionless during this period it is immaterial, so far as the going of the
clock is concerned, that the contacts 10 and 11 are compressed, which they are at
this juncture, as will be understood by reference to Figure 6.
But at the same time the arm 33 has come into operation for the purpose of
interrupting the circuit, a movement which begins before the escape-wheel moves
further, and, consequently, before the contacts 10 and 11 have had time to move
apart. When, after the interruption of the circuit, the armature 2 recedes,
together with the arm 33 the said contacts 10 and 11 are separated from each
other owing to the wide space there is now between the prongs 32, before the
circuit is restored again; whereby the immediate repetition of an interruption
of the circuit is obviated. The striking train of the clock is connected with the
electrical armature, whereby it is operated through the agency of the following
mechanism;
The striking train is provided as usual with a striking plate 39 mounted upon the
hour wheel arbour, and with a toothed segment 40 revolvably mounted next to such
plate, which, when the clock is about to strike falls with a projecting arm 41 upon
one of the effsets of the division plate 39. The moment when the clock is to strike
is determined by a disc or plate 42 secured to the minute wheel arbour and formed
with a helical plane. This plate 42 operates a lever 43 connected with the toothed
segment. When the time for striking draws near, the lever 43 moves the toothed
segment 40 away from the bottom piece 3, so that it passes the outer end of the
arbour 44, by its own weight, and drops, with the projecting arm 41 upon the
striking plate 39. When the lever 43 presently loses its support at the highest
end of the helical plane of the plate 42, the toothed segment is moved back towards
the bottom piece owing to the action of a spring 46 mounted upon the arbour 47
of the segment. As the toothed segment is thus moved towards the bottom piece,
its teeth come into gear with a pinion 48 on the arbour 5, while at the same time
the segment operates the end of the arbour 44, so that the latter is moved to the
right. At this point the upper portion 49" of a rod 49, which is connected with
the arbour 44 movable in the longitudinal direction which upper portion is turn-
able in the box 70 with relation to the lower part and of the shaft 44, is conducted
into the path of the pins or teeth 50" of a disc 50 secured to the extreme right-
hand end of the arbour 5 (see Figures 4, 4 and 5). As the disc or plate 50 is
turned in the direction of the arrow shewn in Figure 4" its pins alternately lift
the upper portion 49" of the rod 49 which, through the projection 51 of the hammer
tail 53 carrying the head 52, controls the latter.
In order to turn the plate 50 it is necessary to set the armature 2 in operation
.c. to close the electrical circuit; which effect will be obtained at the identical
moment when the segment 40 comes near to the bottom piece 3 in the manner
described above. On the outside of the latter piece there is provided for this
purpose an arc-shaped contact piece 54, while into the disc-shaped toothed seg-
ment 40 a pin 55 is inserted, the inner end of which rests against the contact
piece 54 when the toothed segment 40 returns in the direction of the bottom 3.
At this moment the circuit is closed and passes from the battery 13 through the
wire 14, magnet 1, wire 15, the other magnet 1, wire 16, cut-off 17, wire 18: then
through the clockwork and also consequently through the toothed segment 40
with the pin 55; and further through the contact piece 54 and wire 56 back to the
battery.
On the closure of the electric circuit the electro-magnets are energized, the arma-
ture 2 caused to make a partial revolution, which as hereinbefore described, is
transmitted to arbour 5 and to the hammer actuating disc 50 thereon, causing the
hammer 52 to strike, and at the same time partially winding up the moto:
spring 20.
As the armature oscillates, its arm 33 acts upon arm 32 of the circuit breaker
to interrupt the circuit, as before described, the armature 2 swinging back and
stablishing the circuit again through the circuit breaker, as herein before explained,

page_text: these operations being repeated so long as the pin 55 on the toothed segment 40
remains in contact with the contact plate 54. It will, however, be observed, that
the toothed segment 40 is in gear with the pinion 48 during the described opera-
tions, so that at each partial rotation of said arbour, the segment or lever will be
moved a certain distance away from the snail or towards its normal position, until
it has cleared the arbor 44, at which moment the contact pin 55 on the lever will
be in register with the sleeve bearing 57 in contact 54, thus allowing the spring 46
to further retract the lever, while the arbor 44 is projected forwardly, thereby
moving the sleeve 70 through the arm 49 in a like direction, and withdrawing the
radial arm 49 from the path of the lifter pins 50 on disc 50, the parts being again
in their normal position, as herein before described.
It is obvious that the number of strokes of the hammer 52 will depend upon
the length of time the contact pin 55 remains in contact with the contact plate 54,
and it is further obvious that this is determined by the striking plate 39, since
the greater the amplitude of the throw of the toothed segment 40 towards said
striking plate, the longer will said contacts remain in contact.
The circuit must, in accordance with what is above stated be completely closed
until the pinion has operated the last tooth of the toothed segment 40; but by
that time the pin 55, also, must have come to position directly opposite the aper-
ture 57, which implies a supervening interruption of electrical connection between
the pin 55 and the contact piece 54. This however must be guarded against lest
the above mentioned contacts should be destroyed. To this end an insulated
piece 58 Figure 3 is attached to the bottom piece 3 and connected by the conduc-
tor 59 with the battery 13; such insulated piece 58 also serving as a means for
the attachment of one arm of a U-shaped spring 60. When the arm 33 begins to
oscillate to the left of the position indicated in Figure 3, for the purpose of inter-
rupting the circuit, the free end of the spring 60 is pressed against the arm 33
which condition of things will prevail until the said arm 33, by its movement,
has completed the interruption of the circuit. The circuit is thus broken only in
the cut off however, since, even after the contact between the pin 55 and contact
piece 54 has been destroyed, the current may still pass from the clockwork through
the arm 33 then through the spring 60, piece 58 and conductor 59 to the bat-
tery 13; next through the wire 14, one electro-magnet 1, the wire 15 and the other
electro-magnet 1; and now through the wire 16, the cut-off-switch and the
conductor 18.
The part of the cut-off which acts as an electrical conductor is as before stated
a column of mercury, which is divided by a non-conductor, say, a small plate of
mica if it be desired to interrupt the circuit the characteristic features of thesc
cut-off devices resides in the fact that the column of mercury is formed with a
large sectional area at the point of contact, and that both ends, viz., the mercury
and the mica, are surrounded by an oily liquid whereby an absolutely effective
interruption of current is provided for; for in the circuit breaking arrangements
of this class, hitherto known, this drawback is noticeable, that the mercury escapes
through the slit or seam of the tube surrounding it, so that the column of mercury
gradually shrinks; also, the mercury is apt to burn into and through the lamina
of mica which of course interferes with the proper interruption of the circuit.
These defects are entirely remedied by the lubricating fluid: and owing to the
large sectional area of the mercury column, the further advantage is secured that
the contact surface at all times remains perfectly clean, in-as-much as the impurities
produced by oxidation are displaced in the outward direction.
Figures 8 and 9 of the accompanying drawings show this circuit breaker being,
respectively, a horizontal section and a vertical section thereof.
In the tube 71 is confined a column of mercury 72, the conducting wires entering
the mercury at the two close ends of such tube. In an outer cylinder tightly
enclosing the tube 71, a spindle or arbour 31 is revolvably mounted, said spindle
having a plate 30 of insulating material-preferably mica-secured thereon. The
said tube 71 is cut through on the level of the plate 30; and the groove, formed

page_text: by such cut, being just wide enough for the plate 30 to be moved backwards and
forwards through it with perfect ease whenever the spindle or arbour is turned.
When the plate has moved into the position shown in full lines in Figure 9 it has
thereby completely severed the column of mercury and consequently interrupted
the electrical connection; whereas when the said plate is turned back to the posi-
tion indicated in the same figure in dotted lines, the connection is restored, the
two bodies of mercury, which had been separated, being thereby allowed to unite
into one unbroken body again.
In the cylinder 73 is contained the lubricating liquid by which the mercury is
prevented from adhering to the mica plate.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:—
1. Electrical clockwork the main features of which are, firstly, that the escape-
wheel 8, within the anchor-escapement of the clock, is fitted with a contact-
piece 10, which, during the rotation of the escape wheel S, is adapted to come in
contact with a second electrical contact piece 11, insulated from the clockwork;
and secondly that the mainspring 20 of the clock is connected with an armature 2
revolvable upon an arbour 5; such armature being arranged to be attracted, and
consequently turned, by an electro-magnet 1 electrically connected with the clock-
work; the main spring 20 of the clock being compressed by the said armature 2
and the circuit being thereby closed.
2. In the electric clockwork characterised in the first claim, the arrangements
consisting in the provision of a cut-off switch 17 controlled by the armature 2,
between the electro magnet 1 and the clockwork; which is so connected with the
armature 2 that the current is interrupted before the contacts 10, 11, operated by
the escape-wheel 8, have been moved apart, for the purpose of preventing any
formation of sparks between the said contacts 10 and 11.
3. In the clockwork characterised by the first and second claims, the arrange-
ments which consists in constructing the electrical contacts 10 and 11 which serve
to close the circuit in the shape of a pin 10 projecting from the side of the escape
wheel 8 and of two or more pins or spring wires 11 projecting from the arbour 7
of the pallets 9 into the paths of the pin 10; whereby the relative inward position
of the contact pieces is so adjusted that contact takes place between them the
moment the pallet 35 of the anchor 9 slides over the tooth 36 of the escape wheel 8
which is stationary; all for the purpose of preventing the contacts 10 and 11, when
they meet, from interfering with the proper operation of the clock.
4. In the electrical clockwork characterised in the first claim, the arrangements
whereby the armature 2 revolvable on the arbour 5 is connected with such arbour
by the ratchet-wheel 28 firmly secured upon the said arbor, with which a click 27
secured to the armature is adapted to engage; and wherein the said arbour 5
carries the drum or barrel 21 which serves for securing or retaining the main-
spring 20 of the clock; a click 29, secured to the frame or cage of the clockwork,
being adapted to engage with the said ratchet-wheel 28, whereby the arbour 5 and
drum 21 are prevented from turning backwards after the spring 20 has been wound
up.
5. In the clockwork constructed in accordance with the fourth claim the arrange-
ment wherein on the part of the arbour 5 carrying the armature 2, which is con-
tained in the interior of the drum 21, a helical spring 24 is provided, said spring
being more powerful than the main spring 20; the end of such helical spring
resting partly against the bottom of the drum 21 and partly against the projec-
tion 23 formed on or secured to the said arbour 5, for the purpose of enabling the
drum 21 to revolve upon the arbour 5 in the event of the main spring being over
wound.
6. In the clockwork characterised in the first claim the arrangements wherein
the pinion 48, which, when the clock is about to strike comes into gear with the

page_text: striking train of the clock through the medium of a toothed segment 40 secured
on to the arbour 5 which is set in rotary motion by the armature 2; while the
said segment 40 is provided with a contact piece 55 which comes into contact with
another contact piece when the pinion 48 is thrown into gear in the manner just
stated the said second contact piece being arranged in a convenient position on
or in the clockwork, but insulated therefrom; a pin-wheel 50 being furthermore
secured to the arbour 5 of the armature 2 and serving to operate with striking
hammer 52 by means of its pins or sprockets; all for the purpose of enabling the
armature 2 to be turned backwards and forwards after the circuit has been closed,
according as the current is cut off by the switch 17 or turned on again; thereby
causing the clock to strike and imparting rotary motion to the toothed segment
and also eventually guiding such segment so that it remains out of contact with
the contact piece 54.
7. In the clockwork constructed in accordance with the sixth claim, means for
preventing sparking between the contacts 54 and 55 referred to in the sixth claim
when the current is cut off after a rotary movement of the toothed segment 40;
the arrangement consisting of a spring 60 secured to but insulated from the clock-
work at one of its extremities, while its other free end lies in contact with a
movable piece 33 firmly connected with the armature 2, while this armature is
performing its own movements, for the purpose of bringing about an interruption
of the circuit.
8. In the clockwork constructed in accordance with Claim I a circuit-breaker
of mercury wherein the column of mercury, being a conductor of electricity, is
adapted to be cut through by a reciprocating thin plate of insulating material
such as mica or the like, moving at right angles to a set column of mercury, for
the purpose of interrupting a current; the main feature being that both parts
viz., the column of mercury and the insulating plate are located within a case or
chamber filled with a lubricating liquid, for the purpose of preventing the mercury
from burning on or into the said insulating plate, and eventually burning through
the same.
Dotad ih 101.
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.