Year: 1887

page_text: Date of Application, 12th Apr., 1887.
Specification Accepted, 13th May, 1887.
I, ALBERT L. PARCELLE, a citizen of the United States, residing at Boston, in the
County of Suffolk, and State of Massachusetts, U.S.A., Electrician, do hereby declaro
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 :-
Heretofore a swinging pendulum driven by an electro-magnet or magnets, whose
circuit is made and broken by the pendulum, has been used to drive the clock-train.
Such pendulums have, however, been ordinary. pivoted rigid pendulums, or have been
suspended by a small metal plate or spring in a manner very common and well
understood. All such apparatus is, however, more or less defective on account of
inequalities in the arcs described by such pendulums in oscillating at different
amplitudes.
The purpose of my invention is mainly to remedy such defects and produce an
electric clock of great uniformity, regularity, and certainty of action. With this
object in view I employ a resilient vibrator which is flexible or elastic in its entire
length. A pendulum of this character describes an approximately true cycloidal arc
and is isochronous under such degrees of amplitude as are required for the operation
of clock mechanism.
So far as I am aware I am the first to use an electrically driven pendulum which
drives the clock train and is resilient throughout its length, and I consider it a primary
feature of my invention. I also use such a pendulum in clocks of other kind. Other
novelties in the structure and organization also belong to my invention, and are
claimed below.
In the accompanying drawings-
Figure 1 is a front view of one form of my invention with the clock face partly
broken away;
Figure 2 is a side elevation of the same;
Figures 3 and 4 are respectively a front view and side elevation on an enlarged
scale of other switch devices and mechanism for driving the clock train by the
pendulum; and
Figures 5 and 6 are detail views illustrating another manner of driving the clock
train from the pendulum.
In the particular organization in which I have chosen to illustrate my invention,
Price Q77

page_text: A represents a vertical frame or back-board on the face of which a casting or frame B,
preferably of metal, carrying the clock-mechanism is maintained. On the upper end
of this frame a split post B¹ is carried or formed, in which the pendulum or vibrator C
is fimly held.
Near the lower end of the frame Fig. 1 are brackets on which motor magnets B² B²
are supported. A bob or weight C' is preferably carried on the end of the pendulum
or vibrator, and may be either a solid mass of metal, or other suitable material, or a
hollow vessel in which shot, sand, or mercury may be placed.
The armature e for the motor magnets B2 B2 is preferably secured upon the lower
end of the pendulum. The magnet or magnets for driving the pendulum may of
course be arranged in any suitable relation to the armature, though they are preferably
arranged as shown, so that the faces of their poles are out of the path or line of
vibration; whereby the pendulum is permitted to swing freely on either side without
coming in contact with the magnets.
and
B B indicate a battery, one pole of which is connected with the magnets B²,
from thence with the switch-brushes s, the opposite pole being connected with a metal
frame or carrying plate B, which is in electrical connection with the contact plates
carried by the switch-block S, as clearly seen in Fig. 1. The sliding block S, of
non-conducting material, moves laterally upon holding and guiding screws as it is
shifted back and forth by the pendulum.
The exact time of movement of the switch may be regulated by means of the
adjusting screws thereon, and the contact of the switch-brush s with the contact plates
on the switch-block may be regulated by adjusting the brushes in their,supports;
see Figs. 1 and 2.
The switch brushes which run upon the sliding block S are each movable endwise
in a socket-piece mounted on the end of an insulating post. The outer end of the
brush is turned down and formed with an eye through which an adjusting screw
working in the block or insulating post passes. Between the downwardly-turned end
of the sliding brush and the socket-block is interposed a coiled spring. On
manipulating the screw the brush may be adjusted end wise.
An impulse of vibration having been imparted to the elastic pendulum, the circuit
of the battery B B, will be alternately completed in the magnets B², and the
movement of the switch by the pendulum will maintain it automatically in vibration.
By adjusting the brushes so that contact will be made on one side before it is
broken on the other, a closed circuit battery may be used.
The clock-train may be of any ordinary construction, but with my improved resilient
pendulum, which is exceedingly uniform in action, a train of the simplest character may
be employed.
Upon reference to Figs. 3 and 4, the preferred manner of working the train from
the elastic pendulum will be plain.
A depending arm D at its lower end embraces the edge of the pendulum, and at its
upper end is fast to a small rock-shaft a pivoted in the clock-train frame and carrying
a cross-army on which are pivoted pawls d. These gravity pawls engage the ratchet-
wheel of the train, as clearly apparent, as the arm D is moved in both directions by
the vibrating pendulum. This construction is similar to that shown in Figs. 1 and 2,
The arcs
except that the arm D engages the pendulum below the pivot of the arm.
described by the end of the arm and the vibrator at that point approximately coincide
instead of being opposed to each other, as is the case where the arm is connected
above its pivot, as in Figs. 1 and 2.
The vibrator may be constructed to make one vibration per second, and in order to
facilitate its adjustment to that rate the bob may be made hollow, as before mentioned,
and filled with some finely-divided weighting substance, so that it may be regulated
with the greatest exactness.
The bob may be supported on the pendulum by an adjusting nut at its bottom;
and in order to still further provide for the nice adjustment and rate of the pendulum,
a sliding weight F may be moved thereon and held by a set-screw.
Instead of using two brushes and two magnet poles opposite to the end of the

page_text: vibrator, a single brush S and one magnet B2 may be employed as in Fig. 3, the
natural resilience of the vibrator serving to return it properly to the field of the
magnet. The arrangement will be plain from the drawing and does not require more
specific description.
Stops d¹ may be provided against which the ends of the pawls d strike when moved
a given distance, so as to throw the pawls out of engagement with the driving ratchet
wheel. The effect of this arrangement is that the ratchet is driven a given distance
for each vibration irrespective of the amplitude of the vibration.
The pendulum, its magnets, and the other devices, constitute a motor having an
ample capacity to drive the train, and the motor-magnets being placed out of the path
of vibration permit the pendulum to have a large amplitude of motion. As the clock-
train is driven a given distance for each vibration, irrespective of the amplitude of the
pendulum, a battery of a strength slightly in excess of what is absolutely needed may
be employed, and in that case variations in the battery strength will not be noticeable,
or cause any variation of the clock-train..
As seen in Figs. 5 and 6, instead of having the rocking arm D directly embrace the
pendulum, an interposed pivoted arm D¹ may be employed for the purpose.
By mounting all the parts of the apparatus upon a common frame, expansion and
contraction, due to changes in temperature, are in a large measure compensated.
Of course any other arrangement of circuits, other than that shown, may be
employed, and obviously many details may be varied.
The elastic pendulum may be accurately adjusted so as to have a normal rate of one
beat per second at the particular locality where the clock is situated; and having, as
before suggested, a surplus of power, it will continue to accurately drive the train
irrespective of variations in the battery. Any of the ordinary forms of battery may,
therefore, be used for long periods of time.
The spring-bar pendulum thus driven will, when the battery power is removed,
continue to vibrate in exact time for a period amply sufficient to permit a change of
battery, or the repairing of such slight defects as may arise.
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. The combination, substantially as set forth, of a bar of resilient material forming
an elastic vibrating pendulum capable of bending from end to end, a clock-train driven
thereby, an armature on the pendulum, and a magnetic pole or poles for driving the
pendulum having their faces located outside of the line or path of vibration.
2. The combination, substantially as set forth, of a pendulum formed of a thin bar
of yielding elastic metal, rigidly clamped at one end and capable of bending from end
to end as it vibrates, a clock-train driven by said pendulum, an armature on the
pendulum, an electro-magnet or magnets having their poles located outside of the
path of vibration, and switch devices.
3. A clock pendulum formed of a thin bar of yielding elastic material rigidly
clamped at one end and capable of bending from end to end as it vibrates.
4. The combination of the elastic or resilient arm clamped at one end, constituting
a spring pendulum capable of bending from end to end, a clock-train driven thereby,
an armature on the end of the pendulum, an adjustable weight on the pendulum,
whereby its rate of vibration may be modified, an electric circuit, motor magnets,
and switch devices.
5. The combination of the vibrator, the armature thereon, a motor magnet or
magnets, switch devices, a clock-train, the actuating arm interposed between the
vibrator and clock-train, pawls carried by said arm, the ratchet wheel of the clock-train
with which they engage, and devices which throw the pawls out of engagement with
the ratchet wheel when it has been rotated a given distance by the driving pawls.
6. The combination of the electrically-driven vibrator, the electric circuit, and switch
devices, a clock-train actuated by the vibrator, and actuating mechanism interposed
between the clock-train and the vibrator, whereby the train is driven a definite distance
at each vibration of the vibrator irrespective of the amplitude of vibration.

page_text: 7. The combination of an electrically-driven spring-bar pendulum clamped at one
end and consisting of a bar of elastic material capable of bending in its entire length,
and a clock-train actuated thereby, substantially as and for the purpose set forth.
8. The combination of the electrically-driven spring-bar pendulum, the clock-train
actuated thereby, and the adjustable weight F for varying the normal rate of
vibration.
9. The combination of the electrically-driven spring-bar pendulum, consisting of a
flat resilient bar of uniform thickness and resilience throughout its length, and the
clock-train actuated thereby, substantially as and for the purpose set forth.
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040
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AT
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