Improvements in Electrical Switches or Cut-outs.
Year: 1889

page_text: Date of Application, 27th May, 1889
'Complete Specification Left, 25th Feb., 1890-Accepted, 29th Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in Electrical Switches or Cut-outs.
I, EDOUARD EMMANUEL DE FACIEU, of Elephant Point (near) Rangoon, India,
Clerk Eastern Extension Australasia and China Telegraph Company Limited, do
hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in switches for use on electrical circuits
wherein it is deemed advisable to protect lamps, wires or apparatus from the effects
of currents in excess of those which such lamps, wires or apparatus can safely carry.
This improved switch, which I call a "safety switch" may be used in any such cases
but is more especially useful on incandescent lamp circuits. It has hitherto been the
practice to furnish each incandescent lamp with a "fuse," a contrivance consisting as
a rule of a thin strip, wire or button of some easily fusible alloy which would safely
carry a definite normal current, but would be fused by a more intense current and
so by breaking the circuit saves the lamp to which it is attached.
My "safety switch" fulfils the purpose of both a switch and a fuse, it cannot be
destroyed by any current however strong and will consequently last and work for an
indefinite period. It consists essentially of a contact piece which once set to the
position of "closed circuit " is held down in that position by magnetic attraction, which
magnetic attraction ceases as soon as the current conveyed by the switch increases
by a definite quantity or percentage; the contact piece being then released auto-
matically reverts to the position of " open circuit" and stops the current. I obtain
this result by attaching an armature to the movable contact piece in such a position
that on the arm or contact piece being depressed the armature comes into contact
with a permanent magnet attached to the bed plate of the switch, the attraction of
which is sufficient to hold the arm in that position. I wind the wire through which
the current flows a few turns round the aforesaid magnet in such a manner that
the magnetism of the latter is counteracted to such an extent that it will only just
hold the armature down and no more, and under these circumstances a very slight
increase in the current will cause it to release its hold on the armature which
being impelled by a spring flies upwards and interrupts the current. It will thus
be seen that as long as the current is in excess of that which the switch is constructed
to carry, the contact piece cannot remain in the position of "closed circuit."
In carrying my invention into effect the permanent magnet of horseshoe pattern
has a few turns of the main wire wound over the extremities of its two arms;
between these arms and fixed to the bed plate is a flat contact spring to which is
attached one end of the circuit wire; above this is another contact spring (formed
of spring brass wire) carrying an armature, and at its lower extremity, a thumb
piece which may be of wood, ebonite, glass, china, or any insulating substance. This
thumb piece projects out of the wood casing which has a groove cut into it to allow
the contact piece to move up and down.
The current entering, passes through the contact piece to the bottom contact
spring, thence through the two coils to the other terminal and out of the switch to
the lamp or other apparatus. It is of course necessary to mark the positive and
negative terminals on every switch, since the current has to flow in such a direction
as to counteract the power of the permanent magnet.
It is obviously possible to intervert the respective positions and shapes of the
armature and magnet without introducing any new principle in the switch; thus
the contact piece may be made to carry a permanent magnet of either bar or horse-
shoe pattern, the armature being fixed to the bed plate, or else two permanent
magnets may be used, and the coils may be wound over either the fixed or moving
magnet. All these modifications come within the scope of my invention,

page_text: The "safety switch" does not present any difficulty in construction, and may be
made to break contact for a given strength of current with great precision by simply
placing it in a circuit with an ammeter, and regulating the tension of the contact
piece until it breaks contact as soon as the current attains an unsafe or critical
strength. It has this immense advantage over safety fuses, that it will always act
with precision and will not deteriorate by use. It may be made of all sizes.
The preponderance of strength of the horseshoe magnet over that of the contact
piece should be small, a very few turns of wire over the magnet will then be
sufficient to cause it to release its hold. The effect of the coils being also small in
proportion, there will be no danger of permanently reducing the
of the
power
magnet by use.
The end of the contact piece which fixes into the terminal block should be firmly
fixed to it by soldering or otherwise; the armature should also be rigidly fixed to the
contact piece by similar means.
The horseshoe magnet may be raised from the bed plate by means of wooden
cleats having semi-circular grooves cut into them, and may be fixed with wire binders
to the bed plate.
-
In addition to marking the + and terminals, each switch should bear the
maximum current value in amperes which it will take without breaking circuit. The
switch would mostly be used in a vertical position affixed to walls and the like, and
this should be borne in mind when regulating the tension of the contact piece.
Dated this 27th day of bray LOOD.
ED. DE FACIEU.
By Brewer & Son,
33, Chancery Lane, London, Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Electrical Switches or Cut-outs.
I, EDOUARD EMMANUEL DE FACIEU, of Elephant Point (near Rangoon), India,
Clerk Eastern Extension Australasia and China Telegraph Company Limited, 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 improvements in switches for use on electrical circuits
wherever it is deemed advisable to protect lamps, wires, or apparatus, from the effects
of currents in excess of those which such lamps, wires, or apparatus, can safely carry.
This improved switch, which I call a "safety switch" may be used in any such cases
but is more especially useful on incandescent lamp circuits. It has hitherto been the
practice to furnish each incandescent lamp with a fuse," a contrivance consisting as
a rule of a thin strip, wire or button, of some easily fusible alloy which would safely
carry a definite normal current, but would be fused by a more intense current and so
by breaking the circuit saves the lamp to which it is attached from injury.
"
My "safety switch" as hereafter described fulfills the purpose of both a switch and
a fuse, it cannot be destroyed by any current however strong and will consequently.
last and work for an indefinite period. It consists essentially of a contact piece which
once set to the position of "closed circuit" is held down in that position by magnetic
attraction, which magnetic attraction ceases as soon as the current conveyed by the
switch increases by a definite quantity or percentage; the contact piece being then
released automatically reverts to the position of “ open circuit" and stops the current.
I obtain this result by attaching an armature to the movable contact piece in such a
position that on the arm or contact piece being depressed the armature comes into
contact with a permanent magnet attached to the bed plate of the switch, the attraction
of which is sufficient to hold the arm in that position. I wind the wire through which
the current flows, a few turns round the aforesaid magnet in such a manner that the
magnetism of the latter is counteracted to such an extent that it will only just hold

page_text: the armature down and no more, and under these circumstances a very slight increase
in the current will cause it to release its hold on the armature which being impelled
by a spring flies upwards and interrupts the current. It will thus be seen that as long
as the current is in excess of that which the switch is constructed to carry, the contact
piece cannot remain in the position of "closed circuit."
In order that my invention may be fully understood and readily carried into effect
I will describe the same with reference to the accompanying drawings, in which similar
letters of reference refer to like parts in all the figures.
Figure 1 is a vertical longitudinal section shewing a safety switch constructed
according to my invention, and Figure 2 is a horizontal section of same.
Figure 3 is a perspective view of the movable contact piece. Figure 4 is a
perspective view of the magnet, and Figure 5 is a diagram shewing the formation of
the circuit.
A is the armature, B is the arm or contact piece, C is the permanent magnet, D is
the contact spring, E is the bed plate.
The permanent magnet C of horseshoe pattern has a few turns of the main wire
wound over the extremities of its two arms; between these arms and fixed to the
bedplate E is the flat contact spring D to which is attached one end of the circuit
wire see figures 2 and 5, and above this is the contact arm or piece B which may be
formed of spring brass wire and carries an armature A.
At the extremity of the arm B, a thumb piece B' which may be of wood, ebonite,
glass, china, or any insulating substance, is provided. This thumb-piece projects as
shewn out of the wood casing which has a groove cut into it to allow the contact
arm or piece B to move up and down.
In Figure 1 the arm B is shewn as being in contact with the bottom contact
spring D, and conveying to it the current which the said arm B receives from the
terminal block T to which it is rigidly attached.
The current entering, say at T see Figure 5 passes through the contact piece B to
the bottom contact spring D, thence through the two coils W W to the other
terminal T', Figures 4 and and out of the switch to the lamp or other apparatus.
It is of course necessary to mark the positive and negative terminals on every
switch, since the current has to flow in such a direction as to counteract the power of
the permanent magnet.
It is obviously possible to intervert the respective positions and shapes of the
armature and magnet without introducing any new principle in the switch; thus the
contact piece B may be made to carry a permanent magnet of either bar or horseshoe
pattern, the armature being fixed to the bed plate, or else two permanent magnets may
be used, and the coils may be wound over either the fixed or moving magnet. All
these modifications therefore come within the scope of my invention.
The safety switch, according to my invention does not present any difficulty in
construction, and may be made to break contact for a given strength of current with
great precision by simply placing it in a circuit with an ammeter, and regulating
the tension of the contact piece B until it breaks contact as soon as the current attains an
unsafe or critical strength. It has this immense advantage over safety fuses that it
will always act with precision and will not deteriorate by use. It may be made of
all sizes.
The preponderance of strength of the horseshoe magnet C over that of the contact
piece B should be small; a very few turns of wire over the magnet will then be
sufficient to cause it to release its hold. The effect of the coils W W being also
small in proportion, there will be no danger of permanently reducing the power of
the magnet C by use.
The end of the contact piece B which fixes into the terminal block T should be
firmly fixed to it by soldering or otherwise; the armature A should also be rigidly
fixed to the contact piece B by similar means.
The horseshoe magnet C may be raised from the bedplate E by means of wooden
cleats E¹ having semi-circular grooves cut into them, and may be fixed with wire
binders E to the bedplate.

page_text: In addition to marking the + and terminals, each switch should bear the
maximum current value in amperes which it will take without breaking circuit. The
switch would mostly be used in a vertical position, affixed to walls and the like,
and this should be borne in mind when regulating the tension of the contact
piece B..
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 1
claim is :
:
First In electrical switches, the movable arm B carrying either a permanent
magnet, an electro magnet, or preferably a mere armature A, in combination with
another armature, electro magnet or permanent magnet C, all arranged, constructed
and acting in such manner that the said arm B being moved to "close circuit"
will be held down in that position by the magnetic attraction between such part A B
and the part C substantially as set forth.
Second: In electrical switches, providing either the permanent or electro magnet
carried by the movable arm B, or the fixed permanent or electro magnet C, with a
coil or coils of wire through which the current circulates in such a direction as to
counteract to any desired degree, the inherent or induced magnetism of such permanent
or electro magnet substantially as set forth.
Dated t019 2310 day of
ebruarv
XUM
Dated GOIS ZOLO day of Hebruary
E. E. DE FACIEU.
By Brewer & Son,
33, Chancery Lane, London, Patent Agents.