Improvements in Electric Bells.
Year: 1889

page_text: Date of Application, 3rd Apr., 1889
Complete Specification Left, 1st Jan., 1890-Accepted, 8th Mar., 1890
Improvements in Electric Bells.
We DAVID REID, and JAMES KEAN, both of 18 Cambridge Street, Glasgow, in the
County of Lanark, North Britain, Philosophical Instrument Makers do hereby declare
the nature of this invention to be as follows:-
This Invention relates to Electric Bells and is designed for the purpose of providing
an electric bell which can be rung with less battery power than those in ordinary
use.
In carrying out our Invention we employ a relay connected to the battery and bell,
and we use the same battery for actuating both the relay and the bell, one terminal of
the coil of the relay is connected to one pole of the battery direct, and the other
terminal of the coil of the the relay is connected to the other pole of the battery through
the bell-push, or other contact maker which may be at a considerable distance from
the bell. One pole of the battery is also connected to the armature of the relay
while the other pole of the battery is connected through the circuit of the bell to a stop
of the armature. This second circuit is completed when the armature is attached
to the stop. When it is desired to ring the bell, contact is made at the bell-bush, or
other contact maker. This completes the circuit of the relay and the whole current
from the battery flowing through the coil of the relay magnetises the soft iron core
which attracts the armature till it comes in contact with the stop. This completes the
The resistance of
bell circuit, and sends part of the current through the bell coils.
the coil of the relay is much greater than that of the bell coil, so that, although
sufficient current goes through the relay to keep the armature in contact with the stop
after it has been once attached to it, the greater part of the current goes through the
circuit of the bell, and causes it to ring. At every brake of the bell vibrator the bell
circuit is broken and the full current goes through the relay. Thus the magnetism
of the core.is maintained strong enough to keep the armature pressed against the
stop.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Petitioner's Agents.
COMPLETE SPECIFICATION.
Improvements in Electric Bells.
We, DAVID REID, and JAMES KEAN, both of Cambridge Street, Glasgow, in the
County of Lanark, North Britain, Philosophical Instrument Makers 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:
This Invention relates to electric bells and is designed for the purpose of providing
an electric bell which can be rung with less battery power than those in ordinary
use.
In carrying out our Invention we employ a relay connected to the battery and bell
and we use the same battery for actuating both the relay and the bell; one terminal
of the coil of the relay is connected to one pole of the battery direct, and the other
terminal of the coil of the relay is connected to the other pole of the battery through
the bell-push or other contact maker which may be at a considerable distance from the
bell. One pole of the battery is also connected to the armature of the relay, while the
other pole of the battery is connected through the circuit of the bell to the stop of
the armature. This second circuit is completed when the armature is attracted to the

page_text: stop. When it is desired to ring the bell, contact is made at the bell-push or other
contact maker. This completes the circuit of the relay, and the whole current from
the battery flowing through the coil of the relay magnetizes the soft iron core, which
attracts the armature till it comes in contact with the stop.. This completes the bell
circuit and sends part of the current through the bell coils. The resistance of the coil
of the relay is much greater than that of the bell coil, so that although sufficient
current goes through the relay to keep the armature in contact with the stop after it
has been once attracted to it, the greater part of the current goes through the circuit
of the bell and causes it to ring. At every brake of the bell vibrator the bell circuit
is broken, and the full current goes through the relay. Thus the magnetism of the
core is maintained strong enough to keep the armature pressed against the stop.
In order that our Invention may be properly understood and readily carried
into effect we have hereunto appended an explanatory sheet of drawings in the
several Figures of which corresponding parts are marked with the same letters
of reference.
Figure 1 shews the method of connecting the bell and relay in accordance with this
Invention, and Figures 2, 3, and 4 illustrate modifications in which the bell and relay
are combined.
In Figure 1, A is the relay; B the bell; C the key or push for completing the
circuit to ring the bell; and D is the battery. On making the connection at C
the current from the battery passes through the line wires and relay, and the soft
iron of the relay is magnetized. The armature a of the relay is attracted and the
circuit of the bell is completed by making the connection at a¹.
The current
from the battery is thus divided, part going through the bell, and part through
the line and relay. The bell circuit is arranged to have much less resistance than
the line and relay. Thus the greater part of the current will go through the bell
and cause it to ring. At every brake of the bell vibrator the bell circuit is
broken, and the full strength of the current from the battery goes through the
relay. Thus the magnetism of the core of the relay is maintained strong enough
to keep the armature pressed against the stop a'. In this way the armature and
bell are alternately fed from the same battery.
The arrangement may be modified so as to have the relay and bell combined,
as shewn at Figures 2 and 3.
Figure 2 shews an iron rod turned out so as to form two reels; the upper reel
filled with silk covered wire acts as a so-called single pole bell, the other reel
filled with a finer wire forms a single pole relay.
On making the connection at the push the current goes through the relay coil, and
the armature a is attracted till it comes in contact with the stop a¹. A second circuit
is thus completed through the armature a, the metal core of the bell coil, and the bell
coil, and as this latter circuit is of small resistance, sufficient current passes to ring the
bell.
In Figure 3 the two reels shewn have a few layers of fine wire, which is the relay
coil. The yoke a of the magnet is connected to the framework by a light flat spring,
so that it serves as the armature for the relay. On the top of the fine wire there is
wound a thicker wire, which forms the bell coil. When the line wires are connected
the current from the battery passes through the fine coil, attracts the armature of the
relay (the yoke of the bell magnet), makes the contact at a³, short circuiting the
battery through the metal core and the thick wire coil, causing the bell armature
(the yoke of the relay magnet) to be attracted. By means of any of the foregoing
plans a 4-inch bell may be easily made to ring on a circuit of 100 Ohms. resistance
(about 4 miles of No. 11 iron telegraph wire) by means of one Leclanche cell. Two
cells will ring a 6-inch bell at the same distance. For shorter distances-say 1' mile
of No. 11 iron wire-the fine wire coil may be dispensed with; the one coil being
used alternately as the relay and as the bell coil.
The connections are shewn at Figure 4. In this arrangement the coils, should be
wound with as high a resistance as is consistent with ability to give a good strong
ring; for the higher the resistance the better will be the relay action. In following

page_text: the path of the current it will be seen that the weak line current first passes through
the coils magnetizing the cores just enough to pull up the relay armature and
make the contact at a. When this is done, the current has as before a choice of two
paths, one through the line and coils, the other through the wire E and coils. The
current is thus split into two parts, both of which pass through the coils, each helping
to attract the armature and ring the bell.
A good modification of this plan is to wind the magnet with a pretty high resistance
and connect the contact stud a not with the outer end of the coil but with some of
the convolutions nearer the core so as to cut out the outer convolutions and so reduce
the resistance of the ringing circuit.
Other modifications for carrying out our Invention may readily be suggested, and
the foregoing are given as illustrations.
Having now particularly described and ascertained the nature of our said Inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
The arrangement of bell relay and battery by which only one battery is required
for actuating the relay and ringing the bell.
Dated this 31st day of December 1889.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Agents.