Year: 1888

page_text: Date of Application, 18th Jan., 1888
Complete Specification Left, 20th Sept., 1888
--- Complete-Specification Accepted, 26th Oct., 1888
I, MARTIN PULVERMANN, of No. 12, Cooper's Row, Crutched Friars, in the city
of London, Merchant, do hereby declare the nature of this invention (a communi-
cation from abroad by Carl Bohmeyer, of Halle on the Saale, in the Empire of
Germany) to be as follows:-
-
This invention relates to electric clocks and has for its chief object to remove the
armature of the electro magnet as far from the arbor of the time wheel as possible
whereby the resistance to the movement due to the weight and length of the hands is
reduced to a minimum and consequently also the quantity of electricity necessary for
operating the clock.
According to my said invention the time wheel is operated through the medium of two
levers which at one end are pivoted on the same axis as the time wheel. The other
ends of the said levers are connected to the two ends of a lever secured upon the same
axis as a rocking armature, so as to rock therewith.
The said armature is polarized and is arranged in connection with the poles of an
electro magnet the cores of which are connected to a permanent magnet so that they
are constantly magnetized.
The armature is of such form that it cannot be in contact with both poles of the
electro magnet simultaneously so that if an alternating current is passed through the
coils of the magnet it will cause the magnet to attract and repel the two ends of
the armature alternately owing to the polarization of the latter and thus cause the
rocking of the same. This rocking motion is communicated to the levers to cause
them to oscillate in opposite directions.
Each lever carries a pawl in engagement with the time wheel which pawls operate
the said wheel alternately, that is to say, when one pawl is moving the wheel, the
other is sliding back over the teeth thereof and vice versa. Stops are provided to
limit the motion of the said pawls.
It is obvious that a single current can be caused to operate several clocks so that
the latter will move synchronously.
Dated the 10th of In
1000

page_text: Improvements in Electric Clocks.
I, MARTIN PULVERMANN, of No. 12, Cooper's Row, Crutched Friars, in the City of
London, Merchant, do hereby declare the nature of this invention (a communi-
cation from abroad by Carl Bohmeyer of Halle on the Saale, in the Empire of
Germany) 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 elecric clocks, and has for its chief object to remove the
armature of the electro magnet, as far from the arbor of the time wheel as possible
whereby the resistance to the movement due to the weight and length of the hands,
is reduced to a minimum and consequently also the quantity of electricity necessary
for operating the clock.
In order to enable the invention to be fully understood, I will describe how it can
be carried into practice by reference to the accompanying drawing, in which
Figure 1 is a back elevation of the mechanism of an electric clock constructed
according to this invention, and
Figure 2 is a side elevation of the same.
Similar letters in both the figures indicate similar parts.
According to my said invention, the escapement wheel d is operated through the
medium of two levers a and b which at one end are pivotted on the same axis c as the
escapement wheel. The other ends of the levers a and b are connected at e and f
respectively to the two ends of a lever g secured upon the same axis h as a rocking
armature so as to rock therewith.
The armature i is polarized and is arranged in connection witn the poles j and k of
an electro magnet the cores of which are connected to a permanent magnet m·so
that they are constantly magnetised.
The ends of the cores which project from the coils 1, 2 are almost half cut away, as
shown in figure 2 so that the ends of the armature work close to the faces thus
formed without touching them, and by this means the ends of the armature are
strongly attracted by using only a weak current.
The armature i is of such form that it cannot be in contact with both poles of
the electro magnet simultaneously so that if an alternating current is passed through
the coils of the magnet it will cause the magnet to attract and repel the two ends of
the armature alternately owing to the polarization of the latter, and thus cause the
rocking of the same. This rocking motion is communicated to the levers a and b to
cause them to oscillate in opposite directions.
Each lever a and b carries a pawl n and o respectively in engagement with the
escapement wheel d, which pawls operate the said wheel alternately, that is to say,
when one pawl is moving the wheel the other is sliding back over the teeth thereof
and vice versa. The pawl o is pivotted to a curved plate a¹ forming part of the
lever b.

page_text: A stop p is provided on the curved plate a' and a similar stop q is provided on the
lever a to prevent the pawls from lifting after each forward movement of the escape-
ment wheel d and thus temporarily prevent the further forward movement of the
said wheel.
s, are the usual motion wheels, t is the minute hand, and u the hour hand.
The action is as follows :-
-
The parts of the clock being in the position shown in figure 1 if an electric current
be sent through the coils 1, 7 of the electro magnet in one direction the pole k will
attract one end of the armature i whilst the pole j will repel the opposite end of the
same. The levers a and b will be thereby operated by the lever 9 and the pawl o of
the lever b will carry the escapement wheel d forward one tooth and thereby operate
the hands of the clock the other pawl n meanwhile riding over the teeth; the free end
of the pawl o will then be under the pin or stop 7 and the escapement wheel will thus
be prevented from making any further forward movement. The electric current then
passes through the coils 1, 1, in the opposite direction and the pole j will attract while
the other pole k repels the armature i which therefore oscillates on its pivot h and
moves the levers a and b back into the position shown in figure 1. The pawl n is
thus caused to move the wheel d another tooth forward and to come under the pin
or stop p while the pawl o rides over the teeth. The said pin or stop p and pawl n
now lock the wheel so as to prevent its further forward movement until the levers a
and 6 are again operated in a reverse direction by an opposite current and so on.
It is obvious that a single current can be caused to operate several clocks so that
the latter will move synchronously.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed, I declare that what I claim is :—
(1) An electric clock in which a polarized armature gives motion to two levers
each actuating a pawl in such a manner that the said pawls, through suitable gearing,
alternately operate the escapement wheel so as to advance the hands of the clock,
each pawl in turn temporarily preventing the further forward movement of the
escapement wheel after such pawl has advanced it one tooth.
(2) The improved electric clock herein before described and illustrated in the
accompanying drawing.
Dated the 20th dow of Sautronban 1000