Improved System of Fitting up Electric Bells.
Year: 1897

page_text: Date of Application, 4th Mar., 1897
Complete Specification Left, 4th Dec., 1897-Accepted, 26th Feb., 1898
Improved System of Fitting up Electric Bells.
I, HENRY WILLIAM JOHNSTON, of Dunros, Strathtay, in the County of Perth,
North Britain, Gentleman, do hereby declare the nature of this invention
to be as follows:-
This invention relates to an improved system of fitting up electric bells and a
new plan for indicating where the call has been made.
In carrying out my invention I employ only two main wires and branches from them
to the various contact makers. The indicator is actuated by an electro magnet
in circuit with the two main wires the armature of which is connected to an escape-
ment and escapement wheel in such a manner that with each completion of the
circuit the escapement wheel is allowed to turn to the extent of a space between
two pallets. The escapement wheel is actuated by a spring or weight. On the
same spindle as the escapement wheel there is an indicator which moves in front
of a dial to show the number of times the circuit has been completed. When the
spindle carrying the escapement wheel begins to turn it completes the bell circuit
and the bell continues to ring till the indicator is put back to the zero position.
The pushes or contact makers at the various places are constructed so that when
operated in order to ring the bell they each make a different number of contacts
and brakes and the circuit of the electromagnet is completed a different number
of times for each place. Thus the escapement wheel will be allowed to revolve
by a different number of steps for each place, and the indicator will show where
the bell has been rung.
The contact maker may be constructed either to pull out or turn round in order to
make the required number of contacts. The moving part of each contact maker is
provided with the required number of metallic pieces separated by insulating material.
When the contact maker is worked each metallic piece completes the circuit and
the insulating material breaks the circuit. Thus the circuit will be completed
and broken the required number of times at each place.
Dated this 2nd dose of Hamb
1907
BOTTOMLEY & LIDDLE,
154, St. Vincent Street; Glasgow,
Applicant's Patent Agents.

page_text: 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 an improved system of fitting up electric bells and a
new plan for indicating where the call has been made.
In carrying out my invention I employ only two main wires and branches from them 5
to the various contact makers. The indicator is actuated by an electro-magnet
in circuit with the two main wires, the armature of which is connected to an escape-
ment and escapement wheel in such a manner that with each completion of the
circuit the escapement wheel is allowed to turn to the extent of a space between
two pallets. The escapement wheel is actuated by a spring or weight. On the
same spindle as the escapement wheel there is a pointer which moves in front
of a dial to show the number of times the circuit has been completed. When the
spindle carrying the escapement wheel begins to turn it completes the bell circuit
and the bell continues to ring till the pointer is put back to the zero position.
The pushes or contact makers at the various places are constructed so that when
operated in order to ring the bell they each make a different number of contacts
and brakes and the circuit of the electro-magnet is completed a different number
of times for each place. Thus the escapement wheel will be allowed to revolve
by a different number of steps for each place, and the pointer will show where
the bell has been rung.
The contact makers may be constructed either to pull out or turn round in order to
make the required number of contacts. The moving part of each contact maker is
provided with the required number of metallic pieces separated by insulating material.
When the contact maker is worked each metallic piece completes the circuit and
the insulating material breaks the circuit. Thus the circuit will be completed
and broken the required number of times at each place.
In order that my invention may be properly understood and readily carried into
effect I have hereunto appended one sheet of drawings of which
Figure 1 is a diagram of the improved system.
Figure 2 is an elevation of the indicator.
Figure 3 shows the interior of the indicator.
Figure 3 is an enlarged view of the escapement.
Figure 4 is a plan of the indicator.
Figures 5 and 6 represent one form of contact maker.
Referring to Figure 1, A, A, A, are the various contact makers connected by branch
wires B, B, to the main wires C, C. D is the battery for actuating the electro-
magnet in the indicator G, E is the bell, and F the bell battery. The indicator
consists of an electro-magnet a Figure 3 in circuit with the main wires C, C. The
armature of this electro-magnet is connected by an arm b₁ to an escapement b.
The arm 6' is pivoted at 62 and the other end of the arm is connected to the spiral
spring 6 which pulls this end down. The escapement b engages in the teeth of
an escapement wheel c on the same spindle e às the pointer d Figure 2, which
moves in front of the dial f. This escapement wheel is actuated by a spring or
weight c. Every time the circuit of the electro-magnet is made the armature is
attracted and the escapement is tilted. The right hand pallet then engages with
a tooth of the escapement wheel. When the circuit is broken the spiral spring b
draws the armature away from the electro-magnet and the left hand pallet again
engages with a tooth of the escapement. Thus for each make and brake of the
electro-magnet circuit the escapement wheel is turned to the extent of one tooth.
On the spindle e there is a cam g against which a metal spring h presses. When
the pointer is at zero the spring presses against a piece of vulcanite or other insula-
ting material, but when the escapement wheel begins to turn the spring comes
on to a strip of metal and so completes the bell circuit. One wire of the bell circuit
is connected to the terminal k which is in metallic connection with the metallic
strip on the cam g. The other part of this wire is connected to the metal spring h.
When the pointer is at zero the spring is pressing against the vulcanite and the bell
circuit is broken, but when the escapement wheel begins to move the spring presses

page_text: on the metal strip and the bell circuit is completed. The bell continues to ring
till the pointer is turned back to the zero position. In order to prevent two calls
being made at the same time I provide a vessel i containing mercury pivoted to the
framework, which when the pointer is at zero is held in a level position by the
arm j attached to the spindle e as shown in Figures 3 and 7 but when the escape-
ment wheel begins to turn the arm j releases the mercury vessel and the spiral
spring tilts it as shown in Figure 8. One of the main wires is broken and con-
nected to two terminals in the mercury vessel. When the vessel is level the two
parts of the main wire are connected by the mercury and the circuit can be completed
by the contact makers, but when the vessel is tilted the mercury runs to one end
and the connection between the two parts of the main wire is broken and the circuit
cannot be completed by the contact makers until the pointer is put back to zero.
Between the two sides of the mercury chamber there is a small aperture at i the
size of which can be regulated by means of the screw i. The mercury having to
flow through this aperture when the trough is tilted it will take a few seconds
to drain through and the two parts of the main wire will remain connected while
the contact maker is being operated.
One form of contact maker is shown at Figures 5 and 6. In Figure 5 the cover
is partly cut away to show the interior. The cover can be turned round by the
handle and is provided with a number of studs 7, the number corresponding to
the number of makes and brakes to be made by the contact maker. As the cover
is turned round each stud comes in contact with the springy piece m and pushes
it against the spring contact piece n and completes the circuit. Thus for each
complete revolution of the cover of the contact maker the circuit is made and
broken a certain number of times and the escapement wheel is turned through
the same number of teeth. The number of studs is different for each position of the
contact maker. By this arrangement the indicator shows where the bell has been
rung.
The form of contact maker may be varied. It might be an ordinary push which
would be worked by hand to make the number of contacts for the position it is
placed.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:
The improved system of fitting up electric bells by which only two main wires
are required for any number of call stations the call stations being connected by.
branches to the main wires, substantially as described and illustrated on the accom-
panying sheet of drawings.
T
1007
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow,
Applicant's Patent Agents.