Improvements in Synchronised Electric Clocks.
Year: 1899

page_text: Date of Application, 27th May, 1899-Accepted, 1st July, 1899
Improvements in Synchronised Electric Clocks.
We, SIEMENS BROTHERS & Co. LIMITED, of 12, Queen Anne's Gate, Westminster,
S.W., Electrical Engineers, and EDWARD FRIEDRICH HERMANN HEINRICH
LAUCKERT, of 63, Maryon Road, Old Charlton, Kent, Electrical Engineer, 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:—
Our invention relates to the construction and arrangement of synchronised
electric clocks in such a manner as to avoid sparking on changes of contact, and
to ensure accuracy in the movements imparted as we shall describe referring to
the accompanying drawings.
Fig. 1 is a diagram of the electrical connections at the master clock, Fig. 2
is an elevation and Fig. 3 is a plan of part of the contacts and contact springs at
the master clock.
Fig. 4 is a side view and Fig. 5 is a rear view of the operating gear at one of
the secondary synchronised clocks.
The diagram Fig. 1 shews the electrical connections not in the relative positions
that they really occupy but as if they were spread out so as to avoid the confusion
which would result if the one half of the diagram were drawn behind the other
half.
a is a spindle of the master clock which makes one revolution per minute.
It has fixed on it two arms each carrying a roller but the one roller b is in front
of the other roller c. Each of these rollers as it revolves acts on a projection
depressing a spring, the roller on spring e, the roller e on spring d, these two
springs being side by side as shewn in Fig. 3. A battery of which ƒ and g are
the poles, a resistance and electro-magnet coils i of the secondary clocks (of which
three are indicated) are connected to contracts as shewn, both springs d and e
being connected to one pole f of the battery. When the roller 6 depresses the
spring the connection of spring e with the pole f is broken and connection is
made with pole g so that a current passes from through the magnet coils i in
the one direction and back to the pole f. When the roller e depresses the
spring d, the connection of spring & with pole f is broken and connection is mado
with pole g so that now a current passes through the magnet coils i back to f but
in the opposite direction. Thus every half minute a current is transmitted to the
magnet coils of the secondary clocks, but these currents alternate in direction
so that one of the poles of these electro-magnets is strengthened and the other is
weakened alternately every half minute.
As shewn in Fig. 2 one of the springs, d, normally makes two contacts, the
one connecting it to the resistance, the other k to the battery pole f. When d
is depressed the contact k is broken but j remains in contact until d makes contact
with 7 and depresses it. On the backward movement, the contact j is established
before the contact is broken, so that no sparking occurs at the break of
contact. The contacts made by the spring e are similarly arranged.
As shewn in Figs. 4 and 5 in each secondary clock there is a permanent

page_text: magnet m which by vicinity to an iron spindle carrying an armature n gives it
always the same polarity. On the same spindle are fixed two arms pq linked to two
levers side by side on which are pivoted pawls rs which are engaged with the
teeth of a ratchet wheel t fixed on a spindle of the secondary clock. Under
the armaturen is an electromagnet u having its pole pieces notched to admit
the arms of the armature n. When a current is transmitted from the master
clock it strengthens one pole of the electromagnet u and weakens or even
reverses the other so that one of the arms of n is attracted down thus depressing
one of the pawls rs and turning the ratchet wheel tone tooth. The next current
sent strengthens the pole that was formerly weakened or reversed, and weakens
the pole that was formerly strengthened so that the other arm of n is attracted
down and the other of the two pawls rs is depressed, turning the ratchet wheel
another tooth and so on every half-minute. The spindle of the ratchet wheel t
being suitably geared to the hands of the secondary clock, this clock is obviously
worked in synchronism with the master clock.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is: -
1. In combination with a clock the electrical connections for synchronising
secondary electric clocks substantially as described with reference to Figs. 1, 2
and 3.
2. Electrical synchronising apparatus for secondary clocks, arranged and
operating substantially as described with reference to Figs. 4 and 5.
CITTA
uay
Lana
1033.
ABEL & IMRAY,
Agents for the Applicants.
ABEL & IMRAY,
Agents for the Applicants.