IMPROVEMENTS IN ELECTRIC CLOCKS
Year: 1882

page_text: LETTERS PATENT to Jean Paul Arnold Schlaefli, of Soleure in the Canton of
Soleure, Switzerland and temporarily of Clerkenwell in the County of
Middlesex for an Invention of IMPROVEMENTS IN ELECTRIC CLOCKS
PROVISIONAL SPECIFICATION left by the said Jean Paul Arnold Schlaefli
at the Office of the Commissioners of Patents on the 7th July 1882..
JEAN PAUL ARNOLD SCHLAEFLI of Soleure in the Canton of Soleure,
Switzerland, and temporarily of Clerkenwell in the County of Middlesex
"IMPROVEMENTS IN ELECTRIC CLOCKS."
This Invention relates to an improved secondary electric clock to be actuated
by a weight 'raised periodically by a current sent at frequent intervals from a
central station.
The mechanism of the clock is somewhat similar to that described in the
specification of former Letters Patent granted to Alexander Melville Clark dated
14th June 1881 No 2579. It consists of a horizontal lever of sufficient weight to
actuate the mechanism provided with an armature and raised periodically by an
electro magnet in circuit from the central station, the said lever being provided
with a propelment acting intermittently on the minute wheel arbor whose
movement is controlled by an escapement as hereafter described. The propelment
consists of a ratchet wheel fast on the arbor and having 60 teeth if the current is
Bent every minute, or other number of teeth corresponding to the frequency of the
transmission of the current, said wheel being actuated by an arm or pawl pendent
loosely from the propelment lever and held up to the wheel by a spring.. A spring
click engaging with the wheel prevents its return when the lever and propelment
pawl are raised. A spur wheel on the same arbor gears with a pinion on the axis
of an escapement wheel having three teeth (more or less, according to the ratio of
the wheel and pinion) at wide intervals around its circumference, with which.
engage a spring detent which is raised by and with the propelment lever to permit
the advance of the escapement wheel one tooth on the descent of said lever, at
which moment the detent is dropped in front of the next succeeding tooth. The
escapement wheel is held stationary during the rise of the propelment lever by
another detent or brake which comes into action when the first one is disengaged
and is raised free of the wheel by the propelment lever in its descent to permit the
advance of the wheel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Jean Paul Arnold Schlaefli in the Great Seal Patent Office on the
6th January 1883.
JEAN PAUL ARNOLD SCHLAEFLI of Soleure in the Canton of Soleure,
Switzerland, and temporarily of Clerkenwell in the County of Middlesex
"IMPROVEMENTS IN ELECTRIC CLOCKS."
"
This Invention relates to an improved secondary electric clock to be actuated
by a weight raised periodically by a current sent at frequent intervals from a
central station.
The mechanism of the clock consists of a horizontal or gravity lever of sufficient 1
weight to actuate the mechanism, provided with an armature and raised periodically
by an electro magnet in circuit from the central station, the said lever being
provided with a propelment acting intermittently on the minute wheel: arbor
whose movement is controlled by an escapement as hereafter described more
fully in detail with reference to the accompanying drawings which represent 1
different views of a secondary clock.
Figure 1 is a rear elevation of the clock mechanism with the back plate of the
frame removed. Figure 2 is a plan, and Figure 3 is,a side elevation of the
mechanism.
1
A is the lever by whose gravity the mechanism is intermittently actuated. It 2
is pivoted at a between the front and back plates. of the clock. frame. Its short
arm carries the armature B of an electro magnet. C fixed at one side of the. frame
and whose coils are connected with the terminals D D',. the one directly and the
other through the metallic frame of the clock. E is the propelment arm or pawl
pendent from the gravity lever A to which it is loosely pivoted at e. This pawl 2
is pressed by a spring e¹ into engagement with a ratchet wheel F fast on the
minute hand arbor G, the said wheel having 60 teeth if the current is sent every
minute, or other number of teeth corresponding to the frequency of the trans-
mission of the current. A click ƒ pressed by a spring fl into engagement with
the wheel F prevents its return when the lever A and propelment pawl E are 3
raised. A spur wheel H also fast on the minute hand arbor G gears with a
pinion i on the axis of an escapement wheel I having three teeth (more or less,
according to the ratio of the wheel and pinion and the intervals at which the
current is transmitted) at equal distances around its circumference with which an
escapement detent K on an arbor k¹ is made to engage by a spring k.
detent K is raised when the lever A rises by an arm a¹ which takes under it and
is attached to the lever A in order to permit of the escapement wheel I being
advanced one tooth by the descent of said lever A, at which moment the detent K
is dropped in front of the next succeeding tooth of the wheel. The escapement
wheel I is held stationary during the rise of the gravity lever A by another detent 4
or brake L.which is pressed by a spring against the wheel I when the detent K
is disengaged and is raised free of the wheel by a stud on the gravity lever
pressing in its descent upon the tail end of the detent in order to permit the
advance of the wheel.
The
This clock has no pendulum or balance wheel to regulate its rate of going, which 4
is dependent only upon the frequency of the transmission of the current, the
minute hand being moved intermittently at minute intervals over the distance of
one minute space on the dial and remaining stationary between whiles. The
minute hand is fixed on the arbor G and the hour hand is actuated therefrom
through the usual "motion work."

page_text: The line wire is attached to the terminals D D', of which the one D is in
electrical connection with the back plate of the clock frame, and the other is
insulated therefrom. The electric current is transmitted periodically by the closing
of the circuit by a normal clock at a central station as is well understood, a
number of these secondary clocks being placed in the same circuit and actuated
from the normal clock,
Having described the nature of my Invention and the manner of performing the
same, I declare that what I claim as my Invention to be protected by the
hereinbefore in part recited Letters Patent is.
1st. The combination and arrangement of clock mechanism, substantially as
herein shown and described for operation by the periodical transmission of the
electric current, as specified.
2nd. In an electric clock the combination with the electro magnet, the gravity
lever, and the propelment as described, of the escapement controlled substantially
as shown and described by the gravity lever for limiting the movement of the
hands at each descent of the gravity lever.
In Witness whereof I the said Jean Paul Arnold Schlaefli have hereunto set
my hand and seal this twenty eighth day of December A.D. 1882