Improvements in or relating to Electric Bells.
Year: 1893

page_text: Date of Application, 15th June, 1893
Complete Specification Left, 14th Mar., 1894-Accepted, 14th Apr., 1894
PROVISIONAL SPECIFICATION.
Improvements in or relating to Electric Bells.
I, CHARLES TURNBULL Junior of Hylton Lodge, North Shields in the County
of Northumberland, Electrical Engineer do hereby declare the nature of this
invention to be as follows:-
This invention refers to improvements in or relating to electric bells and consists
in a special arrangement or combination of parts having for its object an improved
regulation or adjustment of the period of electrical contact whereby improved
results may be obtained from the bell.
To accomplish my purpose I find that the following simple arrangement of
mechanism effects superior results: The armature may be hinged pivotted or
otherwise secured at one end so that when the electrical circuit is made the
magnets shall draw it to them and in so doing the opposite end of the armature is
brought against or caused to strike one end of a suitably centred or hinged straight
bent or otherwise formed lever the other end of which carries the bell hammer.
The armature thus throws up or causes the hammer to impinge against the bell
which not only by this special construction effects the ringing of the bell but a
break of the circuit is likewise effected by the impulse the re-making of the circuit
being effected by the return under the action of spring power or gravity of the
hammer or bar centred as described which conveys the current.
Thus when ringing the bell there will be a constant and uniform make and break
of the circuit between the armature and the end or a point on the hammer bar and
this motion will be for the most part governed by the vibratory or other action of
the hammer bar itself instead of by the armature as is the case in most existing
instances and by the improved construction described more uniform and effective
impacts are delivered and in the case of large bells the bell is enabled to be worked
into a state of vibration and consequent resonance incapable of being produced
under the ordinary systems hitherto in use. By a modification the armature end
may be connected to the hammer bar at or about the point where the latter is
hinged or centred so that the prolongation of the bar inay make and break the
circuit with a fixed stop in connection with the battery or generator, the current
passing from the magnets through the armature and bar to the stop aforesaid.
The electric magnets may be of any convenient or special type or construction
and they may be electrified from any convenient source or generator.
Another special advantage accruing to this improved construction is that the
make-and-break point between the armature and the lever aforesaid is automatically
kept cleaner or freer from oxidation than in the arrangements at present in use
whereby greater convenience and economy ensue.
Dated this 14th day of June 1893
A. CRAWHALI CHAPMAN,
3, St. Nicholas Buildings, Newcastle-on-Tyne, Patent Agent.

page_text: Improvements in or relating to Electric Bells.
1, CHARLES TURNBULL Junior, of Hylton Lodge, North Shields in the County
of Northumberland, 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:-
This invention refers to improvements in or relating to electric bells and consists
in a special arrangement or combination of parts having for its object an improved
regulation or adjustment of the period of electrical contact whereby improved
results may be obtained from the bell.
To accomplish my purpose I find that the following simple arrangement of
mechanism effects superior results: The armature may be hinged pivotted or
otherwise secured at one end so that when the electrical circuit is made the magnets
shall draw it to them and in so doing the opposite end of the armature is brought
against or caused to strike one end of a suitably centred or hinged, straight, bent
or otherwise formed, lever the other end of which carries the bell hammer. The
armature thus throws up or causes the hammer to impinge against the bell which
not only by this special construction effects the ringing of the bell but a break of
the circuit is likewise effected by the impulse the re-making of the circuit being
effected by the return under the action of spring power or gravity of the hammer
or bar centered as described which conveys the current.
Thus when ringing the bell there will be a constant and uniform make and break
of the circuit between the armature and the end or a point on the hammer bar and
this motion will be for the most part governed by the vibratory or other action of
the hammer bar itself instead of by the armature as is the case in most existing
instances and by the improved construction described more uniform and effective
impacts are delivered and in the case of large bells the bell is enabled to be worked
into a state of vibration and consequent resonance incapable of being produced
under the ordinary systems hitherto in use.
By a modification the armature end may be connected to the hammer bar at or
about the point where the latter is hinged or centred so that the prolongation of the
bar may make and break the circuit with a fixed stop in connection with the battery
or generator, the current passing from the magnets through the armature and bar
to the stop aforesaid.
The electric magnets may be of any convenient or special type or construction
and they may be electrified from any convenient source or generator.
Another special advantage accruing to this improved construction is that the
make-and-break point between the armature and the lever aforesaid is automatically
kept cleaner or freer from oxidation than in the arrangements at present in use
whereby greater convenience and economy ensue.
I will fully describe my invention with reference to the accompanying drawings
in which Figures 1 and 2 show a front elevation and an underside plan view, Figures 3
& 4 showing front elevations of modified forms of the same apparatus and in the
following description like marks of reference designate like parts.
Referring to the drawings (Figures 1 and 2) a represents an electrical magnet
mounted on a wooden frame a¹ and a' is the armature hinged at a³ in bracket b.
The arm or extension 4 of the armature is designed to make and break contact with
the arm 5 centred at 6 in bracket b'; the arm 5 also carries the hammer bar 8
and hammer 9; 10 is a gong-bell; B represents the battery, T the terminals and T'
the wires leading from the battery round the magnet and thence when the circuit is
completed, through bracket armature a² extension 4 arm 5 and bracket b².

page_text: The operation and precise novel effect produced from the improved construction
described is as follows:
When the current is switched on from the battery the magnet attracts the
armature. The armature raises arm 5 and when the armature strikes the magnet the
contact is instantly broken because the momentum imparted to the hammer causes
arm 5 to continue travelling in the same direction until it strikes the bell. The
armature rebounds from the magnet and falls back onto the adjusting screw S and
the hammer rebounding from the bell, the arm 5 renews the contact with arm 4 of
armature when the operation is repeated.
Thus instead of the armature governing the motions of the hammer bar as
hitherto has been the case, the latter governs the armature motions so that not only
is the armature made to keep time with the hammer but the periods of electrical
contact between 4 and 5 are more prolonged whereby a more powerful and efficient
impact is obtained.
In Figure 3 the armature is pivotted to the hammer-bar at N, and P is a fixed
point or fulcrum (and also a terminal) where make-and-break of contact is effected.
Thus when the armature strikes the magnet the contact is broken by the momentuin
in hammer causing end E of bar to depart from P, as shown in the drawing the
rebound of the hammer causing the contact between E and P to be renewed.
In Figure 4 wherein two magnets are shown mounted on a light frame-work
the bent end 4' of the armature is used to make and break contact with the arm 5
of the bell crank centred at 6 in insulated bracket ; the arm 7 in this case
carries the hammer bar 8 and hammer 9.
It will be observed that in the apparatus described the electrical circuit is not
broken until the armature actually has struck the magnet and that the contact must
break at this particular point the result of which is that the hammer is thrown
against the bell with great force whereas if the contact was broken before the
armature struck the magnet, the force of the hammer against the bell must be
materially reduced.
Immediately contact is broken the armature falls back its full distance onto the
regulating screw S where it waits until the haminer falls back to renew the contact
and repeat the operation.
Further, electric bells constructed as herein described have a great range of
power, for if a powerful battery is connected to the bell the adjusting screw may
be set back to increase the armature stroke in which case the hammer will hit the
bell with very powerful blows whereas as hitherto constructed increase of battery
power has the chief effect of increasing the frequency instead of the actual power
of the blows.
The strokes of the bell are by my invention so distinct that the vibration of the
gong is not unduly interfered with as in bells hitherto constructed.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In electric bell apparatus the combination with an electro-magnet and
vibrating armature having a fixed extension 4 thereon of a vibrating arm 5 pivotted
at 6 carrying the hammer-bar 8 and hammer 9 the make-and-break point of the
electrical circuit being between the extension 4 aforesaid of the vibrating armature
and the vibrating arm 5 substantially. as and for the purpose set forth with reference
to Figures 1 and 2 of the drawings.
2. In electric bell apparatus the combination with an electro magnet and
vibrating armature having a fixed extension 4 thereon the travel of the said
armature being regulated by screw S of a vibrating arm 5 pivotted at 6 carrying
the hammer-bar 8 and hammer 9 the make-and-break of the electrical circuit being
between the extension 4 aforesaid of the vibrating armature and vibrating arm 5
substantially as and for the purpose set forth.
3. In electric bell apparatus the combination with an electro magnet and

page_text: vibrating armature having a fixed extension 4 thereon the outer end of which is
pivotted to an intermediate point N on the hammer bar of a make-and-break point of
electrical circuit between the inner or shorter end E of the hammer bar extension
and point P to which the circuit wire is connected the several parts being
arranged and adapted to operate as set forth with reference to Figure 3 of the
drawings.
4. In electric bell apparatus the combination with an electro-magnet or magnets
and vibrating armature having a fixed extension 4, 4" thereon of a vibrating
bellcrank 5, 7, pivotted at 6 carrying the hammer-bar 8 and hammer 9 the make-
and-break point of the electrical circuit being between the extension 4" aforesaid
of the vibrating armature and the arm 5 of the vibrating bellcrank substantially
as and for the purpose set forth with reference to Figure 4 of the drawings.
5. In electric bell apparatus the combination or arrangement of parts comprising
the several improvements herein described, the parts being arranged, designed and
adapted to operate in the several instances substantially as and for the purpose
herein set forth.
Dated this 13th day of March 1894.
A. CRAWHALL CHAPMAN,
3, St. Nicholas Buildings, Newcastle-on-Tyne, Patent Agent.