Year: 1887

page_text: Date of Application, 21st May, 1887.
Specification Accepted, 21st June, 1887.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E. 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 :—
Most of the self acting electric clocks now in use are going rather irregularly,
because they are either too much dependent on the strength of the current or receive
their impetus at irregular intervals; the contact makers also are mostly defective.
In the clockwork represented in the accompanying drawings these defects aro
entirely avoided because in this construction the motive force is not electricity but a
spring by which also the oscillation of the pendulum is regulated. The pendulumi.
receives its impetus exactly every minute or half minute according to whether the
clock is to indicate seconds or half seconds.
The mechanism of the clock is represented in Figs. 1-4 as applied to a seconds
pendulum and in fig. 5 to an anchor escapement. Figs. 6-9 represent different
constructions or modifications of the contact maker. The principal advantage of this
construction is that it has no wheels whatever with exception of those for the hands
and that it may be used as a motor for synchronising other electrical clocks.
A wheel A with 60 teeth carries on its spindle the mechanism for the hands.
Beneath the wheel A is the electro-magnet B which when the circuit is closed operates
the armature fixed on lever C. To this lever C is pivotted a pawl D which moves the

page_text: wheel A for the space of one tooth at each movement of the armature. A catch E
and the screw F prevent the wheel A from moving more than one tooth at a time.
The stroke of lever is limited by the insulated screws a and b. The screw bis
provided with an ebonite pin c while screw a has a platinum armature which makes
contact in case the clock is used to regulate and synchronise other clocks. To the
upper part of the frame is pivotted an elbow lever & in the vertical arm H of which
is journalled the spindle of a wheel J with 30 teeth subject to a little friction from .a
spring e. On the end of the spindle is mounted or fixed a boss f which carries two
pins g and Fig. 3, which do not turn in the same plane. A pawl K engages with
the teeth of the wheel so that at every movement of the elbow lever the wheel is
moved one tooth. The screw i prevents the wheel from moving more than one tooth.
Above the lever C is a small two armed lever L the lower arm of which is always in
contact with lever C under the influence of a spiral spring k. The lever will
always abutt against the screw b when the current is not closed because it is under the
influence of the spiral spring which is stronger than k. The upper arm of lever L
ends in a bevilled pallet face as also does the arm M pivotted to one arm of lever G.
The spring may be replaced by an adjustable weight m as represented in fig. 4.
Level with the centre of the wheel J a slide n is loosely attached to the frame which
slide carries two pins o and p corresponding to pins g and h (fig. 3). To the outside
of the slide is fixed a platinum point q and opposite this fixed to the frame an insulated
contact springr.
When the clock is to be set going the pendulum is set in motion with the elbow
lever G attached thereto and the pawl K will move the wheel J for the space of one
tooth with every reciprocating movement of the pendulum. The pins g and h will
also be turned with the wheel J and when they come into a horizontal position the
pin h will move the pin p and with it the slide n to the right thus establishing contact
between g and r.
The course of the current now is as follows: The positive current passes from the
springs fixed to the frame (fig. 2) to the insulated spring t fixed to the plate of the
works. This establishes the communication between the frame and the works. From
the spring the current passes through the electromagnet B to the contact spring to
the slide n and through the works to the negative pole. At the same time the
electro-magnet B will attract the armature with the lever C which will move to the
right and the pawl D will move the wheel A one tooth. As soon as this is done
the lever L will be free and its upper arm will press against the inner side of arm M.
When the pendulum now swings back the pallet face will touch, the spring & will come
into action and give the pendulum a fresh impetus. After a time the pin g will move
the pin o with the slide n to the left and the current will be broken because the
contact between q and r is broken. This play will be repeated with every revolution
of the wheel J which will be every minute with a seconds pendulum. If a half
seconds pendulum be used either transmission gear of two to one must be used for the
hand mechanism or the wheel A must be provided with 120 teeth.
In figure 5 the same mechanism is represented adapted to clocks with anchor
movement. The anchor N carries the wheel J at its lower arm while the upper arm
engages with the catch of the balance. The lower arm also ends here in a pallet face.
The action is the same as in the pendulum clock with exception of the mechanism
for the hands which is actuated in a different manner.
The pivot o of the lever carries a small toothed segment u which gears with a
pinion provided with two bevilled catches x, y one of which always engages with the
wheel P having 60 teeth. With each movement of the lever C the catches x, y will
alternately engage with the wheel P and move this for the space of one tooth. In this
case also the contact will be made every minute as the balance makes one reciprocating
movement every second.
If line wires be connected to the screws z and w this clock may be used to
synchronise others.
Figures 6 to 8 represent a mercury contact which consists of a segment Q pivoted

page_text: to the frame and carrying a rectangular arm R provided at its outer end with a
platinum pin. The segment is provided with the pins o and p and is held in position
by means of the spring S. The small boss ffixed to the spindle of the wheel J has in
this instance only the pin h while the pin g is fixed to the lower part of the
pawl H at T.
The action is easy to understand when the pin moves the pin p the segment Q
will be moved also and with it the arm R the platinum pin of which will dip into the
mercury contained in the cup U fixed to but insulated from the frame thereby making
contact. When the pendulum returns the pin g will move the pin o and the segment
will return into its original position consequently the platinum pin will be withdrawn
from the mercury and break the contact.
Figure 9 represents a sliding contact the springs and wo of which are made of
platinum.
Figures 10 and 11 represent the invention adapted to an electric pendulum clock the
hands of which are moved through the movements of the pendulum and in which the
contact is made by the diminution of the oscillations of the pendulum.
The mechanism consists here also of a wheel with sixty teeth A' which is turned
through the movement of the pendulum. The electro-magnet B₁ attracts the
armature C¹ for the purpose of actuating the lever D₁ provided with pallet faces a¹ b¹.
The wheel F on the arm E' carries a boss c¹ to which is fastened a pin d¹. After
every revolution of wheel F' the said pin d¹ will move the pin e¹ on the anchor and
thereby the anchor itself which by means of its pallets and g¹ will move the wheel A'
for the space of one tooth. A spiral spring will return the anchor into its original
position behind the electro magnet B' an arm H' is fixed to the arm E¹ which arm H¹
makes the contact. To the lower end of this arm H is pivoted a small wedge shaped
piece of steel h¹ which slides over a small notched piece of iron J¹ fixed to the contact
spring. When the arc described by the pendulum diminishes the steel piece ¹ will
not fall off the notched iron J¹ and during the return motion of the pendulum the
piece will engage in the notch of J¹ thus depressing the spring i the platinum pin m²
of which will be immersed in the mercury in the cup n¹ thus making contact. The
lever D¹ will now actuated by the spiral spring o¹ give the pendulum a fresh impetus.
It is easily understood that the length of the are described by the pendulum and
consequently the intervals between the contact makings can be regulated by the
spiral spring o'. The stronger the tension of the spring the stronger will be the
impetus given to the pendulum and the longer will be consequently the arc described
by the latter as also the intervals between the contact makings.
To ensure certain contact a platinum plate p¹ is moreover fastened to the contact
spring which plate p¹ makes contact with the contact screw y¹ when the spring is
depressed.
Having now particularly described and ascertained the nature of the said invention
as communicated to me by my foreign correspondent and in what manner the same is
to be performed-I declare that what I claim is:—
1. In electric pendulum clocks the combination of a lever such as L having a pallet
face at one end with an arm or lever such as M having a pallet face to engage with
that of the lever L substantially as and for the purpose herein specified.
2. In electric pendulum clocks in which the contact is made by the diminution of
the are described by the pendulum and in which the hands are also moved by the
motion of the pendulum the combination of a lever such as D' having pallet faces such
as a band a spiral spring such as o for the purpose of giving the pendulum a
uniform impetus at regular intervals independently of the strength of the current
substantially as specified.
3. In electric pendulum clocks the combination with wheel J of contact making
apparatus consisting of pins g and h slide piece n and pins op operating substantially
as and for the purpose specified.

page_text: 4. In electric pendulum clocks contact making apparatus consisting of a segment
lever such as Q carrying pins op in combination with wheel J pins g and harm R and
mercury cup U substantially as specified and shown in figures 6, 7 and 8 of the
accompanying drawings.
5. In automatic electric clocks with balance mechanism the combination with
wheel J of an anchor such as N pallet lever L and adjustable, spring k substantially as
and for the purpose specified.