Improvements in Electric Apparatus for the Control of Watchmen.
Year: 1886

page_text: Improvements in Electric Apparatus for the Control of Watchmen.
We, OTTOKAR SKRIVAN, Manufacturer, and FRANCIS DVORÁK, Electrician, both of
Vinohrady, Prague, Bohemia do hereby declare the nature of our invention for
IMPROVEMENTS IN ELECTRIC APPARATUS FOR THE CONTROL OF WATCHMEN and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement :—
The object of our invention is to manufacture and apply improved electrical
apparatus for the control of watchmen, and to secure proper attention to their duties.
Our invention consists in the application of an improved controlling clock;
improved dials in electric communication with such controlling Clock; and an
improved arrangement of electric bell, in combination with a normal Clock and
switch.
Fig. 1 shews the system when no current is passing..
Figs. 2 and 3 respectively shew the system when the switch is arranged for the
bell to give single strokes, and to ring continuously as hereafter explained.
Referring to Fig. 2, VIII is the arrangement of the electric bell apparatus, the
bell itself being removed to shew the position of the electro magnets. This consists
of a metallic plate upon which the two magnets are fixed. The plate is formed with
three terminals 15, 16 and 17, to which the wires 8, 10 and 14 are attached.
When the current passes by the wire 10, through the terminal 16, to the one
magnet 19 only, and back through the terminal 17 and wire 14, the armature 18 is
drawn to and retained by the one magnet 19, and the hammer strikes the bell but
once. But when the current is passed by the wire 8, terminal 15, through both
magnets 19 and 20, and back through the terminal 17 and wire 14, the lammer
attached to the arm 18 then strikes the bell continuously, on the well-known make
and break system-VII is a normal Clock having a plate revolving with the minute
hand once every hour, upon which are fixed 4 studs r, r, s, s, which consequently
make and break contact every quarter of an hour, m. m are the contact springs.
The watchman's dials, shewn in Figs. 6, 7 and 8, and the positions of which are
indicated by the numbers I. II. III. and IV, in Figs. 1 2 and 3, consist of a dial
plate Fig. 6, and ratchet and contact mechanism, as shewn in Figs. 7 and 8 ; Fig. 7
being a side view and Fig. 8 a back view.

page_text: The position of the controlling Clock is shewn at IX in Figs. 1. 2 and 3, and
enlarged in Figs. 4 and 5; Fig. 4 being a plan view and Fig. 5 an end view of
the same.
The Levers c. c¹ form armatures of the electro magnets M and M', the spring L
having a tendency to withdraw the armature from the magnets.
The Lever c, contact spring c and ratchet 6 form an escapement which controls the
rotation of the ratchet wheel b. This ratchet wheel is attached to the same shaft as
the nut (Fig. 5).
At each change of the magnetic current in M and M' therefore the ratchet b will
make a quarter of a revolution.
In the commutator of each station I. II. III. IV two discs D and E are mounted
on the spindle which carries the hand R (Figs. 6, 7 and 8). The disc D is provided
with four broad teeth (or as many as there are divisions in each hour or other period
of time) which, when the hand R is turned, causes contact with the spring m.
This spring is insulated from its plate. If the hand R is placed on a number, the
current will go through the commutator. It will be interrupted, if the hand R is
placed between two numbers, as well as at the moment of its turning from one number
to the next. To prevent the hand being turned the wrong way, the disc H is formed
with ratchet teeth and a pawl P. This ratchet has twice as many teeth as the disc D,
to ensure the position of the hand R. When the hand R is placed between two
numbers it means Danger."
The dial plates of the controlling clocks being provided with as many divisions and
numbers as there are stations to be visited during the longest night or other period,
each movement of the hand R from one number to the next produces a momentary
interruption of the current, the armature c will be momentarily separated from its
magnets, and again attracted by them, which produces half a revolution of the
ratchet 6 and of the nut f. The hand of the controlling clock then advances a distance
of one division. At the same moment of interruption the bell VIII sounds, after
which the apparatus resumes its normal state, if no interruption has taken place.
The operation of the system is as follows:-
The current from the battery A passes through the wire 1, switch B, and wire 2,
to the plate IX; where it divides, and thence through the electro-magnets M
and M to the stations I II III and IV whence it goes to earth. The armature of
each electro magnet is, as explained, opposed by a spring and has arms c¹ c², which
make contact with the wires 3, 4, when the current ceases to pass through the magnet.
This interruption having been effected by the watchman, the current finds a passage
through one of the wires 3, 4, its course being directed according to the position of
the switch, either through the wires 3 and 10 to the bell VIII, or through the wires 4
and 8 to the bell, returning thence in both cases to the battery by the wire 14.
In the former case the bell gives a single stroke, in the latter it rings continuously,
as explained.
Should the watchman neglect to turn any of the hands R in duo time, and to the
correct numbers, the succession of the contacts g, h, r, r, and s, s, will be disturbed,
and, at the end of the set division of time, the normal clock VII will establish contact
between one of the wires 5, 6, and the wire 7, which joins wire 8, and send the current
from plate IX through the coil of the electro magnet connected with the bell VIII,
thus informing the Controller that the watchman neglected to turn the hand R as he
should have done. The Controller thus discovers at which of the stations the neglect
occurred, on looking at the hands of the controlling clock IX, which will shew exactly
the positions of the hands R.
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. The construction of the station commutator, so arranged that on turning the
hand R the watchman turns also the disc D (with as many teeth of contact as there
are numbers on the dial plate of the commutator) and the ratchet disc H (this disc

page_text: having twice as many teeth as the contact disc) substantially as herein before described
and shewn on the drawings.
2. The construction of the electric controlling Clocks shown in Figs. 4 and 5 with
electro magnets M and M (or one only for each controlling clock), an armature with
escapement, ratchet wheel b, and nut in combination with the pins and alternating
contacts I
and of the same, as well as with the alternating contacts r, r, s, 8, of a
normal clock VII, and in connection with an electric bell VIII, through which the
current is sent each time when an interruption in the circuit occurs or is produced,
either by the commutator or by an accident, substantially as herein before described
and shewn on the drawings.
3. The combination of the contact nut f of each controlling Clock with the
contacts, and s, s of the normal clock VII in such a way, that no current is sent
by the normal clock through the bell VIII if the hand R has been operated,
substantially as herein before described and shewn on the drawings.
4. The application of any ordinary transmitter switch or stop, so as to enable the
controller to send a current through the coil of a second electro magnet connected
with the electric bell, so arranged as to give only single strokes instead of continued
ringing, and so that the regular attendance of the watchman may be communicated
by regular and single strokes of the bell, if desirable, substantially as heroinbofore
described and shewn on the drawings.
Dated this 16th day of December 1886.