Improvements in Electrically Operated Clocks.
Year: 1897

page_text: Date of Application, 31st. Dec., 1897-Accepted, 14th May, 1898,
COMPLETE SPECIFICATION.
Improvements in Electrically Operated Clocks.
I, RICHARD BURK, of the Wurttembergische, Uhrenfabrik Schwenningen," of
Schwenningen, in the Empire of Germany, Watch and Clock Maker, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
This invention relates to a pendulum clock with a peculiarly arranged electric
operating device for the movements and a striking mechanism operated directly
from the pendulum and regulated from the movements.
The operation of the movements is effected from the pendulum guide by a
closing of the circuit only every 40-50 pendulum oscillations, whilst by means
of an induction coil and an armature on the pendulum the gradually diminish-
ing pendulum swing is again rendered fully complete so that it is sufficient again
for a large number of pendulum oscillations. The striking mechanism is operated
by the contact of the pendulum guide on the hammer lever, whilst the larger
force necessary is produced automatically by a more frequent closing of the
circuit on the pendulum oscillations; a separate circuit closing device being there-
fore unnecessary.
As only one closing of the circuit is necessary for the move-
ments after about 40-50 oscillations, sufficient force exists for driving the striking
mechanism as the possibility is afforded of closing the circuit at each oscillation.
In the accompanying drawings:-
Figures 1 to 6 show the means for regulating the closing of the circuits for
the movements, and the operation of the striking mechanism by the oscillating
pendulum guide;
Figures and 5 are rear elevations;
Figures 3 and 4 front elevations; and
Figures 2 and 6 side views of the pendulum clock.
Figures and S are enlarged views of the pawl and ratchet mechanism in two
positions.
Figures 9 to 12 show a modification in which the contact is made by the paw!
directly.
The actual pendulum and the induction apparatus are not shown in the draw-
ing, as both these arrangements are of themselves well known.
The driving or operating of the hand mechanism by the pendulum Figures 1
and 5, takes place in this improved clock from a pawl D mounted by means of a
cock on the pendulum guide B, which pawl engages in a ratchet wheel E from
the arbor of which the hand mechanism is moved by any known means such as
worm gear O, and bevel gearing o², o². The number of pendulum oscillations as
is well known, is dependent on the length iof the penduluin and not on the extent
of swing. Even if the latter be altered; the number of oscillations undergoes no
diminution. The difference in the extent of swing of the pendulum diminishes
only very slightly after each swing, when the movement only is driven, and in
order to cause the induction apparatus to come effectively into operation, when
a given minimum is reached, it requires a larger number of oscillations of the
[Price 8d.]

page_text: pendulum or a corresponding diminution in their extent of swing before the
circuit is effectively closed. The ratchet wheel E must however only be moved for-
ward one tooth even with the largest extent of swing. In order that this may
take place even with larger pendulum swings, slide bridges R and J are arranged
by the side of the ratchet wheel E, which bridges allow the pawl D resting on
the wheel E by its own weight to only move forward the wheel each time to
the extent of one tooth.
In order that the pendulum oscillations, which naturally become smaller, may
still remain large enough to move the ratchet wheel E one tooth further forward,
an induction apparatus is employed, the armature of which is so arranged on
the pendulum that it swings past the poles of the induction apparatus near enough
to be attracted by this latter on the closing of the circuit. The supply wire is
connected with the clockwork by means of terminals M¹ M² insulated from one
another and from the clock, in which terminals there are mounted contact
screws m¹ m³.
In order that the circuit may be closed on a corresponding diminution of the
arc of oscillation of the pendulum B, a series of levers are arranged consisting of
two-armed levers G and H, the latter of which carries two contact springs h¹ h³
which in the normal position of the lever H are kept away from the contact
points m² m² by their own weight.
In the case of too short a pendulum swing, the upper point of the loosely
hanging lever G rests so close to a tooth of the ratchet wheel E that the indenta-
tion lies directly in front of the point. The pawl 1 falling into the indentation,
then lies in front of the point g, and on the pawl moving forward, not only is
the ratchet E moved but the lever G is turned, the under part g¹ encounters. the
lever H, turns the same on its fulcrum and brings its springs ³ ³ into contact
with the contact screws m² m², whereby a circuit is established. This contact is
only momentary as the part g¹ passes over the lever H and allows the latter to
return to its normal position. The arm g' is revolubly. mounted on the end of
lever G in such a way as to be free to swing out sideways, so that on the return
of the lever G the arm g¹ will slide along or run round the bevelled end of the
lever H (Figure 6) into its position of repose without again turning the lever H.
The position of the induction apparatus is such that the armature oscillating with
the pendulum at the moment of the closing of the circuit stands at a suitable
distance from the magnet poles in order to be capable of being attracted by these
latter.
In the case of a sufficiently large pendulum swing, the pawl will not engage
the point g and the lever H will not be operated because in such case the ratchet
wheel E will have been rotated the full extent of one tooth so that the point g will
lie by the side of a tooth and not of an indentation and the pawl D in sliding
down the back of the tooth will thus be kept clear of the point g and will ride
down the back of the latter as shown in Figure 7, whereas in the case of a short
swing of the pendulum the ratchet will be rotated less than the extent of one tooth
and consequently the point will now lie by the side of an indentation instead of
a tooth as shown in Figure 8 so that the pawl in dropping or sliding into the
indentation will encounter the front of the point g and push the latter at the
same time as it pushes the ratchet E.
The striking mechanism is directly operated from the pendulum. In order to
regulate the number of strokes, the same construction is employed as in the
ordinary striking mechanisms. It consists of a star wheel W with a ratchet
snail W pin wheel Zand pawl w, a regulator V with teeth and lever arm V
with pin v to engage the ratchet snail, gathering piece U and faller T¹ with a
releasing elbow piece . This ordinary striking mechanism, by means of a
separate device attached thereon, operates the throwing in or out of action of a
lever S fixed on an arbor 1, on the lower end of which lever a catch is mounted,
Figures 1 and 5. When the lever S assumes the position shown in Figure 5,
the catch will stand over the check lever U3 which is mounted on the same

page_text: arbor 3 on which the hammer arm X of the hammer is mounted. In the position
shown in Figure 1, on the other hand, the catch of the lever S lies in front of
the check lever U³. Consequently in this latter case at each double oscillation
of the pendulum guide B the latter pushes the lever S and the lever U³ is turned
by the catch s¹, that is to say, the hammer is raised and then allowed to fall
and is then caused to strike, whilst in the position shown in Figure 5 the hammer
check lever U³ is not moved. The rod is provided as a check for the hammer
and bears against the cock u to prevent the hammer falling too low (Figure 5).
The throwing into or out of action of the lever S and its catch s¹ is effected by
means of the device shown in Figures 3 and 4.
A cam s³ is fixed on the arbor 1 of lever S, which cam by means of a projection T
on the faller T¹ and also by means of a further separate pawl lever 1 is retained
in this position. During the releasing by the hand mechanism, the faller T" which
is pivoted at 2 is raised by the releasing elbow, Figure 3, which is engaged
by pins carried by pin wheel Z driven from the hand mechanism, and the
projection T is removed from the cam whilst simultaneously a hook 2 of a
further lever T3 pivoted on the faller T engages over the projection of the
lever T. At the conclusion of the throwing into action, that is to say at the
commencement of the striking, the faller T falls back, the hook draws the pawl
lever Tupwards and the hook of the latter releases the cams, so that the lever
arm S mounted on the same arbor with it together with the catch s is free to
move under the impulse of a counterweight on the lever S, into the space
between the pendulum guide B and the hammer check lever U. Each pendulum
oscillation to this side will then be transferred by means of the catch s to the
hammer lever Us and thereby also to the hammer .. Simultaneously with the
striking the rack will be drawn back tooth by tooth by means of a lever U¹
mounted at the other end of the hammer arbor 3, and a gathering piece U having
a tooth u re-engaging in the rack and finally brought into its position of repose.
The faller Twill then drop down into a position of repose, Figure 4, and the hooks t
and of the levers T and T3 will be disengaged so that the cam ³ again lies in
its position of repose and the catch s is retained in the position over the hammer
check lever U³.
The advantage of this striking mechanism is that it requires no electrical device
or separate electrical arrangement, the hammer being caused to strike merely by
encountering the oscillating pendulum.
With no other movement than that herein before described could the striking
mechanism be simultaneously operated, as during the striking considerably more
power is necessary, increasing with the number of strokes. The movements,
immaterially whether they are electrical or driven by weights or springs, must
always have conveyed to them as far as possible an exactly suitable even driving
power, which could not possibly temporarily effect the operation of the striking
mechanism. The permanent increase of the driving power such as would be
absolutely necessary for thus driving the striking mechanism, would lead to such
irregularities in the going that the object of the entire clock would be destroyed
and it would become useless.
The movement herein before described always regulates itself automatically as
is apparent from the specification. Its consumption of power is always exact and
instantaneous, and may increase to a considerable multiple for the requirements
during the striking, as for instance, when only working the clock-work move-
ment a contact is at the most only necessary every 40-50 pendulum oscillations,
whilst in the case of striking which more rapidly diminishes the length of oscilla-
tion of the pendulum the possibility is afforded of having a contact at each
oscillation.
It will be readily understood that whilst I have only described the electric
contact as being made by a series of levers under the action of the pawl D, the
said pawl may itself close the circuit by dropping into contact with a suitable
contact piece. Such modification is shown in Figures 9 to 12 of the accompany-

page_text: ing drawings, in which Figures 9,.10 and 11 are respectively a front view, plan
view, and a section on the line x-x of Figure. 1. Figure 12 similarly to Figure 9
shows the mechanism in a characteristic position of working. The cock d is
omitted in Figs. 9, 11, and 12 for the sake of clearness.
A is the rear frame plate of the clockwork which latter is driven by a recipro-
cating pendulum B by means of a pawl D and ratchet' wheel E. Behind the
pendulum and separated from the plate A by a strip R¹ of insulating material
there is arranged a fixed contact piece P over which the pawl D'extends by means
of a lateral continuation . A lever G provided with a counterweight G¹ is
pivoted at G2 in front of the ratchet wheel E but also within reach of the pawl D
and when in a position of repose is supported by a pin 2. № M³ are terminals,
the latter of which (M) is also insulated from the plate A.
This arrangement works in the following manner:
With a maximum oscillation of the pendulum B, that is to say shortly after
the latter has received an impulse from the electromagnets (which are not here
shown) the amount to which the pawl D each time rotates the ratchet wheel E
is equal to the indentations of the wheel E, that is to say the extent of rotation
is such that the wheel E always and successively remains standing with one of
its teeth in proximity to the upper point of the lever G, or rather with the next
indentation which is to be engaged by the pawl I always covered
by the point of this lever G. The pawl D cannot therefore during such
maximum pendulum oscillations engage the point of the lever G to impart an
oscillation to the latter, but on engaging with the wheel E the said pawl will
always bear on the upper end of the lever G, and, on the rotation of the wheel E,
will slide along this end (see Figure 12) without its arm d encountering the con-
tact piece P.
When however the pendulum oscillations become smaller upon a minimum
oscillation being reached the wheel is no longer moved by the pawl exactly the
distance of from one tooth to the next so that the indentation next engaged by
the pawl is not fully covered by the lever G and the pawl can therefore drop quite
to the bottom of said indentation and thus come in front of the point of the lever G
as shown in Figure 9 instead of riding on the top of said lever as shown in
Figure 12. The arm of the paw! D therefore encounters the contact piece P
and the circuit is closed the current flowing through the contact piece P from the
terminal M to the pawl D, thence through the pendulum B and the pendulum
support (not shown) to the plate A and thereby to the terminal M so that the
electro-magnet-in circuit with said terminals is excited and attracts the pendulum,
thus imparting to the same a fresh impulse. The maximum duration of engage-
ment of the pawl D with the wheel E and lever G, and of the interruption of the
closed circuit, is determined on the one hand by a roller J and on the other hand
by the bevelling of the insulating piece R¹ on which the arm d¹ of the pawl
slides at each end of the pendulum oscillations.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed; I declare that what I
claim is:
on
1. In electrically operated clocks having an increase in the swing of
the pendulum after a number of pendulum oscillations have taken place,
a circuit closing device comprising a lever (G) revolubly mounted
the arbor of the ratchet wheel (E) and a pivoted contact lever (H)
carrying contact springs (h! h³) adapted to be operated by said revoluble
lever (G), the whole characterised by the ratchet wheel (E) being moved
forward only one tooth by means of a pawl (D) mounted on the pendulum guide
at each swing of the pendulum whether the extent of swing be large or small
whilst when the extent of swing is a minimum the pawl (D) comes in front of
-the point (g) of said revoluble lever (G) and in pushing the ratchet wheel forward
also turns said lever which then operates the contact lever (H) and thus moves

page_text: the contact springs of the latter into momentary contact with two terminals
(mm) thereby closing the circuit, substantially as described.
2. In electrically operated clocks such as described, the direct operation of the
striking hammer (X) by the pendulum guide (B), by means of a catch (s) pivoted
on a lever (S) and adapted to drop between the pendulum guide (B) and the
hammer lever (U³) the moment a cam (3) mounted on the same arbor (1) as said
lever is released from a projection (1) on the faller (T) when the latter is lifted
by the ordinary striking mechanism, whilst after the striking is completed and
the faller (T) has descended, the cam (83) and lever (S) are turned back and the
catch (s) is again raised and retained by means of a pawl lever (1) which is
released from a hooked lever (T2) and allowed to engage the cam, substantially
as herein before described.
3. An electrically driven pendulum clock of the kind described characterised
by an oscillating lever (G) being arranged in proximity to the ratchet wheel (L),
which lever with its upper end extends nearly to the height of the indentations
or intervals between the teeth of the ratchet wheel (E), so that during the
maximum oscillations of the pendulum and the maximum rotations of the ratchet
wheel (E), the latter will always remain standing with the next indentation
behind or covered by the point of the lever (G) whereby the pawl cannot drop
quite to the bottom of the indentation between but must in rotating the wheel (15)
slip over the upper end of the lever (G), whilst when the minimum oscillation is
attained the next indentation to be engaged by the pawl (D) is brought in front
of or uncovered by the point of the lever (G) so that the pawi (1) can drop to the
bottom of the interval between the teeth and thus close the electric circuit by
coming in contact with a contact piece (P) substantially as hereinbefore described
ated this 30th day of December 1897.
WM. P. THOMPSON & Co.,.
Of 6, Lord Street, Liverpool, Agents for the Applicant.