Improvements in Electrical Alarm Apparatus.
Year: 1899

page_text: Date of Application, 14th July, 1899
Complete Specification Left, 14th Apr., 1900-Accepted, 30th June, 1900
PROVISIONAL SPECIFICATION.
Improvements in Electrical Alarm Apparatus.
I, CARL EGGERDING, of 2, l'ischer Strasse, Hannover, Germany, Merchant, do
hereby declare the nature of this invention to be as follows:-
In alarm apparatus according to this invention the current is not interrupted
when the apparatus is in action, but is even strengthened by the short circuiting
of the alarm or call-bell. Consequently, when the bell is rung by completing
the circuit by means of a switch or armature, the armature of the bell is held in
contact permanently-i.e. until the circuit is broken at a suitable point. The
armature or switch may be made as a telephone diaphragm to render the alarm
audible.
The apparatus comprises the following parts:
1. A shunt alarm or call bell such that the current is not interrupted but is
short-circuited when the armature approaches the magnet. The same object can
be attained by using an ordinary alarm or call bell and putting a resistance into
circuit in parallel with it, so that only a portion of the current will pass through
the alarm, whilst the portion passing through the shunt will be utilized for
keeping in contact the falling switch or armature hereinafter mentioned under 4.
2. A push which keeps the circuit closed when in its normal position but breaks
the circuit when its button is pressed.
3. A battery.
4. A contact or switch device which comprises an electro magnet and a pivoted
armature. As soon as the armature of this device has fallen, the current is inter-
rupted. When, however, this armature is raised, the current flows from the
battery conductor into this armature and through a projection on one of the cores
of the magnet into the body of the electro-magnet and thence outwards through
the coils. By means of the magnetization of the cores hereby produced, the iron
armature is held in contact with the said projection and at the same time fulfils
a second purpose if the armature be made like a telephone diaphragm, when any
oscillations of the current passing through the coils of the magnet will be made
audible by the magnetic action of the core which is not provided with the pro-
jection and which is preferably the upper core, upon the armature diaphragm.
If the current is interrupted, the armature falls down automatically, or if it be
pulled down the circuit will be broken.
All the said four parts can be connected together in any desired series, but the
parts alarm or call bell and the push should be placed in the room of the person
to be wakened or called (for instance, in the servants bedroom), and the part con-
tact or switch device in the room of the person wakening or calling the other (for
instance in the master's bedroom).
When the apparatus is out of action the current is cut off because the armature
of the contact or switch device hangs down, and the battery therefore cannot
work.
When it is desired to ring the alarm or call bell, the armature of the switch or
contact device is pushed up into contact with the lower core of the electro-magnet
so as to complete the circuit and cause the current to flow from the battery con-
ductor to the armature just mentioned, thence into the body of the magnet and
through the two bobbins into another conductor, thence through the shunt alarm
or call bell and back through the push and another conductor to the battery. In

page_text: consequence of this the alarm or call bell is rung and the armature of the contact
or switch device remains in contact with the core projection, since the shunt
alarm or call bell does not break the circuit. At the same time the oscillations
of the current produced by the shunt alarm or call bell cause the armature of the
switch or contact device to vibrate and thereby make the alarm in the servant's
room audible in, for instance, the master's room.
If, now, the person to be wakened presses the push button, the current is inter-
rupted, and the armature of the switch device falls down and thereby indicates
that the person in question is awake.
Dated this 14th day of July, 1900
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.
SALE Apparatus.
"'
1, CARL EGGERDING, Merchant, of Hannover, Fischer Strasse 2, Germany, 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:-
The present invention relates to an improved electric waker, in which the
current is not interrupted when the alarm is in action, but on the other hand by
the alarm being short circuited the current is reinforced. By this means, after
the alarm has been set in action by closure of the circuit by means of a hinged
contact plate, it is enabled to hold the contact plate permanently on its contact
i.e. until the circuit is broken at a suitable place. The hinged contact may at the
same time be constructed as a telephone membrane for rendering the call audible.
The arrangement is shewn in the accompanying drawing and consists of the
following parts:
1) A short circuit call bell N which does not interrupt the electric current
when in action but short circuits same at the contact a by the approach of the
armature to the magnet. The same purpose can also be effected by the employ-
ment of an ordinary bell and the introduction of a resistance parallel thereto, so
that only a part of the current traverses the former, while the other part the
current passing through the resistance serves to hold the hinged contact plate,
described under 4, against its contact. This parallel resistance must however
possess a large selfinductive power, so that current pulsations or waves emanating
from the bell magnet may be supplemented therein, thereby allowing them to
traverse the magnet of the hinged contact-plate and produce the oscillations of
the same, as will be after described.
2) The press button R. This in its normal condition leaves the circuit closed.
As soon as it is pressed it opens same.
3) The battery B.
4) The contact device k, which is shewn in operation at K¹. It consists of an
electromagnet with the two cores b and c and also of an iron hinged contact
plate d. This latter is shewn at K open, and at K' closed or in the operative
position. With this device the circuit is broken, as soon as the plate has fallen.
When the same is raised the current passes from the line wire IV through the
plate over the contact c, (see K¹) through the body of the magnet and thence
through the coils to the exterior. By the magnetisation of the cores b and c
thereby produced the iron contact plate is held against the slightly protruding
core c.
Simultaneously the plate & performs another purpose, as it is constructed as

page_text: a telephone membrane and renders audible any oscillations in the current pass-
ing through the coils in the manner similar to the action of the alarm apparatus
by means of the magnetic action of the upper core bon the said plate d. When
the current is interrupted the plate falls down automatically and also by pulling
the plate away the circuit is broken.
The said described four parts may be connected up with each other in any
order of precedence however R and N are to be placed in the neighbourhood of
the person to be awakened. (e.i. in the servants bedroom) and K in the neigh-
bourhood of the person awakening same (e.g. in the master's or mistress's bed-
room).
In the inoperative condition the current is interrupted by the hanging down
of the plate and consequently the battery is out of action. Should it be desired
to wake somebody, the plate d is turned up. The circuit is hereby closed and the
current passes from the line wire IV to the plate, over c in the magnet body, then
through the two coils in the line wire 1. "Thence through the short circuiting
call bell N, line wire II, and conducting part of the press button R and line
wire III back to the battery. The bell N is thereby set in action and the plate d
remains in contact with c as the short circuiting call bell does not interrupt the
current. Simultaneously the oscillations in the intensity of the current, pro-
duced by the short circuiting of the bell, set the plate d in vibration, which ren-
ders audible, in, for instance, the mistress's bedroom, the progress in the awaken-
ing of the servant.
If the person to be awakened now presses the press button R, the current is
interrupted and the plate & falls, and indicates thereby that the said person has
been roused.
The arrangement as described is then again in its inoperative position and.
ready to be employed again.
Should it be intented to interrupt the progress of the wakening from the room
of the waker or operator the contact plate d is raised by hand away from c so that
the current is interrupted.
The alarm device as herein before described obviates the drawbacks of the con-
tinuous alarm of hitherto devised constructions and no third circuit is required,
so that the component parts of the device may be brought in connection with any
existing electrical (bell) appliance. Any disputes with the person to be wakened
as to whether the alarm has been in action or not are completely avoided by the
action of the device as described.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is as follows:-
-
1.) An electric waker or call bell consisting of the combination of a short
circuiting bell or call with a falling contact plate held in operative position by an
electro magnet until the circuit is broken by means of a normally closed push
button device, substantially as set forth.
2.) An electric waker or call bell, the whole constructed, arranged and adapted
to operate, substantially as described with reference to the accompanying
drawings.
.
Dated this ffth day of April 1900.
B. REICHHOLD,
International Patent Office, 32, Ampthill Square, London, N.W.,
And at Berlin, Germany,
Agent for the Applicant.