Improvements in and relating to Electric Clocks.
Year: 1896

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Electric Clocks.
We, JACOB WIESNER of 6 Wagnerstrasse Heidenheim-on-Brenz, and
ALBERT. WITZEL of 55 Reinsburgstrasse, Stuttgart, both in the Empire of
Germany, Mechanic and Manufacturer respectively 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 has for its object an electric pendulum clock operated by means
of a special battery or connected with some already existing source of electricity,
and having a peculiar automatically acting regulator. On a small movement
of the pendulum, an electro-maguet is brought into action, the magnet of which,
towards the end of the pendulum swing, attracts a metal plate or armature attached
to the pendulum and thereby makes the shortened pendulum-oscillation again
a complete one. Merely a weak battery is sufficient to maintain the clock in
automatic operation for a whole year and even longer. An already existing house
supply of electricity, such as for signalling devices, bells or the like may also be
used for this purpose.
If, as is generally the case, a striking mechanism be combined with the clock and
the same is arranged to be wound up also electrically in a simple manner by means
of the same device through which the fingers are moved, a stronger battery will of
course be necessary, but even in this case a galvanic battery such as used for an
ordinary electric bell will be sufficient to keep the clock going for a whole year.
As is well known, the strongest battery is rapidly used up where current is
constantly employed; care is therefore taken by means of a special regulator
in this improved electrical pendulum clock, that the electro-magnet shall, according
to the weight of the pendulum, only come into action once for every 10 to 20 or
even more oscillations of the pendulum, that is to say, the battery after each
expenditure of power has again sufficient time to accumulate.
In the accompanying drawings, Sheet 1 shows the general arrangement of an;
electric clock operated by a separate battery; Figures 1 and 2 are front and side
elevations respectively; Figures 3-5 show the clockwork (without the striking
mechanism) in three separate views with a regulating device for effecting the closing.
of the circuit in the case of too small an oscillation of the pendulum. In this case
the necessary switching and regulating wheels are assumed to be arranged on two
spindles. In a further arrangement shown in Figures 6-8, the switching and
regulating wheels are arranged on one spindle. The figures shown on Sheet 2, are
drawn on a larger scale, Figures 9 and 10 showing one and Figures 11 and 12
another form of regulator, or in other words, special mechanism which produces the
closing of the circuit on too small an oscillation of the pendulum and sets the
electro-magnet in operation.
The action of the electro-magnet on the pendulum is as follows:
At the lowest point (or if desired some other suitable point) of the pendulum B,
there is fixed a metal plate or armature K (preferably of wrought iron) which,
towards the end of an oscillation of the pendulum, comes directly over the poles of
the electro-magnet L arranged beneath to one side of the pendulum, and on the
closing of the circuit, which takes place towards the end of the pendulum swing,
the armature K is attracted by the magnet. It is a question, therefore, in the case
of too small a pendulum-oscillation, to produce a closing of the circuit towards the
end of such oscillation.

page_text: The two regulating devices shown in Figures 3, 4, 5, 9 and 10 and in Figures 6,
7, 8 and 11-14 serve for this purpose. In both regulating devices the closing of
the circuit is effected by means of a pivotally mounted lever H or H', the free end
of which, should the movement of the pendulum be too small, drops and rests
on the point of a screw n, whereby a contact is produced. The current supply is so
arranged that assuming the battery P to be arranged on the clock case, one wire
leads directly to the magnet coil L, the other from the battery P to a pin M
fastened in the metallic clock frame A and insulated by means of discs m, and
provided with a contact screw n; any suitable part of the metallic clock frame A
being connected with the coil L by means of a wire. As lever H or the lever H'
are also in metallic contact with the metallic clock frame A a closing of the
circuit is produced, by the lever H or H' resting on the screw n of the insulating
pin M.
In one regulating device the movement of the pendulum is conveyed to ratchet
wheels E and E¹ and from one of these to the finger mechanism by means
of pawls D and D carried by two arms b mounted on the pin of oscillation C of the
pendulum B.
If the striking mechanism is also to be electrically operated, this is effected from
one of the arbors O and O¹ by means of backward transfer wheels on the barrel of
the winding-up spring or the barrel for winding up the weight. A continuous
spring winding-up action then takes place, which is not shown in the drawing on
account of its simplicity.
In order that on the return of the pawls D and D' the ratchet wheels E and E
shall not also be caused to describe a return movement, stop wheels F and F are
arranged in the usual manner on their axes O and O¹ with pawls and engaging
with said wheels F and F.
The lever H is pivoted over the ratchet wheel E on a pin i of an adjustable bar J,
and lies with its projection on the ratchet teeth. This lever H is also provided
with a second projection A, which lies directly over a regulating wheel G which is
fixed on the arbor O', and the function of which is to prevent the lever H descending
at each double oscillation of the pendulum. The lever H rests with its projection A
on the periphery of the disc G which has only a few recesses 9 in such a way that
the lever H can only descend and thus produce a closing of the current if one of the
notches or recesses g lies under the tooth h. Nevertheless a falling of the lever H
is not produced at each notch g, but only when the oscillation of the pendulum is
too small as will be shown in the hereafter described mode of working of
the clock.
The clock runs in the following manner :
If the pendulum B be set in orciliation, the arms & oscillate with it and the
pawls D and D' move the ratchet wheels E and E¹ forward, the arrangement being
such that each regular oscillation of the pendulum corresponds to a rotation to the
extent of one tooth of each of the wheels E and E. If the angle corresponding to
one tooth be called a (Figure 10) the regular oscillation of the pendulum
corresponds to a rotation of the wheels E and E' to the angle a. The regulating
lever H, on which the projections and may be arranged either fixed or
adjustable, is so arranged that when the swing of the pendulumi is a regular one the
projection h rests with its point on the end of the indentation of the teeth e. At
each regular movement forward of the wheel E the projection h will therefore
always rest at the end of the indentation. If the movement of the pendulum be
irregular, that is to say, too small, for instance equal to the angle a' (Figure 10),
the projection & will lie in the indentation instead of at the end, and opportunity is
afforded by this position for the regulating lever H to descend. As mentioned,
the lever H further rests with its second projection A' also on the periphery of a
disc G and a falling or descent of the lever is only allowed when the projection h¹
lies directly over the indentation g of the disc G. Thus the lever H, in order to
fall and produce the closing of the circuit, must lie with its projections and
simultaneously in an indentation of the wheels E and G respectively. This

page_text: engagement naturally lasts only a short time as the indentations g are so arranged
on the disc G that an engagement of the projection h¹ can only take place during a
forward movement (intercalary movement) and the position of rest of the disc G
only takes place when the engaged projection h¹ has again been raised so far that
the lever H no longer encounters the screw n, that is to say when the circuit is
broken.
A second more simple but otherwise similarly working regulating device is
shown in Figures 6-8 on Sheet 1 and in Figures 11-14 on Sheet 2. In this
arrangement in place of two arbors O and Q for the two ratchet wheels E and E¹
and the regulating wheel G, only one arbor O is employed on which the untoothed
ratchet wheel E2, the regulating wheel G, and the toothed counter ratchet wheel F2
are mounted. The arbor O or rather its ratchet wheel E2 is operated from a
lever R revoluble on the arbor O, in a slot of which lever at its upper end a pin r
engages which is connected to the pendulum B and oscillates with it. At the lower
end of the lever R a pawl D' is mounted which moves the untoothed ratchet
wheel E2 forward by clamping it fast. The counter ratchet wheel F2 for preventing
a running back or return movement is assumed to be toothed and a counter pawl f2
engages in the same. A segment shaped projection S is arranged on one of the
sides of the lever R, which projection lies directly against the regulating wheel G
and has its periphery of the same form as the regulating wheel G with the edge of
which it lies flush. A small indentation s is formed in the segment-shaped pro-
jection S and exercises the same function as the wheel E of the regulating device
previously described. A regulating lever H' pivotally mounted on a pin i lies over
this projection S (or the regulating wheel G) as in the first arrangement, but has
only one tooth or projection which bears on the segment S as well as on the
regulating wheel G. If a case arises wherein an indentation g of the regulating
wheel G as well as the notch s of the segmental projection S on the lever R rest
directly under the projection of the lever H', the latter can then fall and make
contact by resting on the screw n.
This regulating device works as follows:-
The indentations g of the regulating wheel G are so arranged according to the
division of the toothed counter ratchet wheel F that one space between two
notches g corresponds to the number of teeth on the wheel F. If the pendulum
makes its regular swing, the tooth ½ of the regulating lever will at the end of one
stroke of the pendulum, stand at the end of the indentation g of the regulating
disc G. If the swing of the pendulum be too small the indentation g comes into
the position shown in dotted lines instead of the oue shown in full lines, that is to
gay under the tooth h. The notch s of the segmental projection S on the lever R
will, at each oscillation of the pendulum or of the lever R, also move under the
projection near the end of the pendulum stroke. If therefore it should happen
that both slots g auds lie under the projection h, the lever H will fall and make
contact. The period of contact of the lever H and the screw n is thus only a
very short one and thus the consumption of the battery current is very
moderate.
The second regulating device is thus very suitable especially for very strong
batteries or for the connection of clocks with powerful sources of current, for
instance such as is employed for electric lighting and the like. It is evident that
the levers H and H' may also be arranged in such a way that the contact may
be established by raising the lever instead of lowering it, which may be obtained,
for instance, by selecting the point of rotation between ¹ and n, Figure 9, or
between h and n, Figure 12.
The disc G and its indentations g are so arranged that the electro-magnet L
only acts when the metal plate or arinature K on the pendulum B approaches it,
and the operation ends as soon as the armature has passed about half the distance
over the magnet coil.
It is assumed in the drawing that the clock drives the fingers mechanism from
the arbor O. The striking mechanism may be constantly wound up (as experiments

page_text: have shown) from the same arbor, or from the arbor O', by means of some
stronger battery without essentially shortening the running time of the clock in
such way therefore that the striking mechanism requires no especial
winding up.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. A clock with means for electrically operating the fingers and striking
mechanism, characterized by two ratchet wheels (E and E') operated by two
pawls (D and D¹) which are mounted on arins (b), b respectively oscillating with
the pendulum (B); and by a regulating disc (G) mounted on the axis of one
of the ratchet wheels, and having its periphery provided with a suitable
number of indentations or notches (g) so that by means of a pivoted lever (H),
having projections or teeth (4 and ¹) which rest on the ratchet wheel (E) and on
the regulating disc (G), an electric circuit is, established by the lever (H) falling
and making contact with a screw point (n) the monent when owing to too small an
oscillation of the pendulum the projections of the lever (H) rest simultaneously in
the indentation between two teeth of the wheel and in an indentation or notch (g)
in the disc (G), whereby an electro-magnet L acting on a metal plate or
armature (K) on the pendulum is excited and attracts the metal plate (K) thereby
bringing the diminished swing of the pendulum again up to its normal extent,
substantially as described.
2. A modification of the herein described device for electric pendulum clocks,
consisting in the employment of one spindle (O) instead of two ratchet wheels (E
and E) and two spindles (O and O') on which spindle an untoothed stop ratchet (E)
a regulating disc (G) and a toothed counter ratchet (F2) are mounted; a lever (R)
caused to oscillate on said spindle by the pendulum (B) and to move intermittently
by means of its pawl (D2) the ratchet wheel (E2) together with the regulating
disc (G); and a segment-shaped projection (S) carried by said lever (R) and
provided with a notch (s), in its periphery, which segmental projection lies directly
beside the regulating disc (G), so that the tooth (h) of the pivoted regulator
lever (H) rests both on the regulating disc (G) and on the segmental projection (S),
whereby when too small a swing of the pendulum takes place, both indenta-
tions (g and s) lie for a short time partially under the projection (h) and allow the
lever regulator (H') to fall, thereby making contact between the lever (H') and a
contact screw (n) in order to excite an electro-magnet substantially as described.
Dated this 10th day of February 1896.
WM. P. THOMPSON & Co.,
Of 6 Lord Street, Liverpool, Agents for the Applicants.