Year: 1898

page_text: I, MAURICE BOUCHET, of 22, Rue Alphonse de Neuville, Paris, France, Engineer,
do hereby declare the nature of this invention to be as follows:-
:-
My invention relates to apparatus for automatically breaking an electric circuit
when the current exceeds a certain intensity. My improved circuit breaker can
either be operated by hand or from a distance and may also be employed as a
switch.
Reference is to be had to the accompanying drawings forming part of this
specification wherein Figure 1 represents a vertical section of the apparatus, the
circuit being closed. Figure 2 is a transverse vertical section on line 1-2
Figure 1. Figure 3 is a horizontal section on line 3-4 of Figure 2. Figure 4
is a vertical section of the apparatus, the circuit being open or broken. Figure 5
is a modification. Figure 6 is a vertical section of a modification. Figure 7
shews the apparatus applied as a bi-polar circuit breaker. Figure 8 represents
the apparatus as provided with a safety device. Figure 9 is a horizontal section
on line 5-6 Figure 8. The same letters of reference denote like parts in all the
figures.
My improved circuit breaker consists essentially of a container (A) of porcelain
or other insulating material provided with two cavities (a), (b), sena-
rated by a partition (c) and containing mercury up to the level (u).
communication with one of
(Figure 4). Each cup (a), (b), is in
the poles of the circuit and in the case of Figure 4 all passage
of the current is prevented by the partition (c). A block (B) of insulating
material forming a pair of plungers of suitable form is disposed above the cavi-
ties (a), (b), and capable of being lowered into the same so as to raise the
level of the mercury to the level (n¹) above the top edge of the partition (c) sn
as to establish electrical communication between the two chambers (a), (b) (see
Figures 1 and 2). On raising plunger (B) the mercury returns to its original
level (n) as shewn in Figure 4, and the breaking of the circuit is produced in the
liquid itself without burning any contact piece, and further the formation of an
arc is prevented, owing to the interposition of the insulating partition between
the two poles of the circuit. The plunger (B) is attached to the core (d) of an
electro-magnet supported on the mercury container (A) by means of a screw
having an insulated head a washer (r) of elastic and insulating material being
interposed between said core and the plunger B.
The electro-magnet may be of any type but preferably I employ a special
arrangement of electro-magnet composed of three parts of magnetic material, riz.:

page_text: A part (D) forming one cheek of the bobbin and provided with a polar tubular
extension piece which while serving for the passage of the lines of force con-
siderably diminishes the reluctance of the interferricum gap; A part (E) forming
the other cheek of the bobbin and provided with a polar extension (e) of decreas-
ing section; A sheath (C) uniting the parts (D) and (E). When no current
passes through the electro-magnet, the core occupies the position represented in
Figures 1 and 2 corresponding to a closed circuit. The reluctance of the inter-
ferricum gap being relatively feeble and that of parts (D) and (E) but trifling,
the action of the ampère turns developed in the coil is directed upon (e) where
the effect is then very powerful. The magnetic flux tends to cause the progres-
sion of the core for increasing the section of passage of the lines of force. The
force exerted between two points of movement of the core will depend upon the
increased section offered to the flow between these two points. Thus by adopt-
ing a suitable shape for the extremity (e) of part (E) the force acting on the core
may be rendered constant. The core (d) is surmounted by a non-magnetic metal
rod (d) sliding freely in the head (E) and is also guided by a disc or washer (R)
placed beneath the head (D). This disc or washer, which is made of insulating
material protects the electro-magnet from all contact of the mercury and forms a
tight joint with the flange of vessel (A).
(M) is a cap or cover for the apparatus provided with a finger piece and which
may be pivoted at (J) in bearings (S) screwed to the sheath (C). The cover (M)
is jointed to the rod (d) so as to partake in the movements of the core (d) and
plunger (B). (P) is a spring jointed at the one end to the pin (J) on bear-
ing (S) and at its opposite end to cover (M) and serving to hold the cover
down when the core is in the position corresponding to closed circuit and to
raise the cover entirely off when the electro-magnet commences to act, the cover
being forced by the spring to pass suddenly from one position to the other,
which movement is effected by placing the pin (G) of the spring below a line
drawn through (J), (J). The inclination of the cover (M) and consequently the
position of axis (G) relatively to the line (J), (J) is regulated by an adjusting
screw for enabling the sensitiveness of the apparatus to be modified. This sen-
sitiveness of the apparatus may also be obtained with the aid of counterweights
balancing the action of the electro-magnet. In this case the spring simply serves
to continue the movement commenced by the electro-magnet and hold the
cover M raised.
The current arrives by the terminal (f), (Figures 2 and 5), which is electrically
connected to the mercury cup (a) by screw (9). The other cup (b) is connected
to the electro-magnet coil by the wire (h). The opposite end of the bobbin is
connected to the terminal (i) by the wire (2).
Supposing the apparatus to be in the position shewn in Figure 4, by press-
ing on cover (M) the core (d) and plunger (B) are caused to descend and the two
members of the latter to dip into the cups (a), (b), of the mercury container
whereupon the level of the mercury will rise above the separating partition (e)
and the cups (a) and (b) will be put in electrical communication and the circuit
closed. Should the intensity of the current exceed the desired limit, the force
exerted upon the core (d) overcomes the resistance of spring (P) and core (d) is
attracted, the spring (P) continuing the movement and maintaining the core (d)
and plunger (B) completely raised, the circuit being then broken and the two
cup no longer in electrical communication. The insulating partition pre-
vents the forming of an arc and the breaking of the circuit being effected, so to
speak, in a closed vessel no alteration of the mercury can take place, it being
possible to place the apparatus in an explosive medium and break the circuit
without any risk of sparking. When the apparatus is raised. as shewn in
Figure 4, the elastic washer (r) abuts against the insulating washer (R) and
makes a tight joint. The apparatus might even be inverted without any of the
mercury escaping.
The wire of the electro-magnet is calculated so as to introduce into the circuit

page_text: only a negligable resistance. In the case of alternating currents the metallic
parts of the electro-magnet would be suitably divided for diminishing induced
currents. The current leads to the mercury cups may be so disposed as to be
out of contact with the mercury when the plunger (B) is raised. The lower ends
of the conductors will thus, as shewn in Figure 5, be above the level of the mer-
cury when plunger (B) is raised.
The action of the plungers is to first put the mercury in each cup in com-
munication with its conductor and then the two cups with each other. Inversely
the breaking of the circuit is only produced between the two cups at the top edge
of the partition (c) between two molecules of mercury and never between the
mercury and the leading-in wires. The apparatus would be mounted upon a
backing of insulating material. The vessel (A) may be provided with any suit-
able number of cups so that the two extreme compartments (a), (b), into which
lead the conducting wires, may be separated by one or several cups (see Figure 6).
Two of these apparatus may be placed side by side so as to constitute a
bi-polar circuit breaker (see Figure 7). In this arrangement the terminals are
placed at different levels so as to avoid the crossing of the wires (A) supposed to
be under casings. The two apparatus may be arranged so as to both break the
circuit at one time by the action of a single electro-magnet, by providing on the
cover (M) of the one apparatus a lug which abuts in rising against
the teeth of small
a
fork mounted oll the cover (M¹) of the
other apparatus, the play between the parts only permitting the appa-
ratus to act mutually by the action of the spring (P) so that the electro-
magnet will have no extra load to overcome. The same arrangement would be
employed for circuits of three or five wires.
The apparatus may be used both as a switch and as a circuit breaker operated
by hand, the cover (M) being raised by hand in the one case and automatically
Without the
operated in the other if the current exceeds the proper limit.
electro-magnet it forms a simple switch possessing the advantages before
described when used as a circuit breaker.
It will be evident that the apparatus may be used as a switch at a distance for
various purposes such as for tramway contacts, rheostats, etc., it being only
necessary to insulate from the main circuit the circuit of the electro-magnet and
to control the latter from any point.
acts a cam
8
a
The apparatus may also be used to limit the supply of current in a subscriber's
circuit for example. In this case it is indispensable that the action of the appa-
ratus cannot be tampered with by keeping the plungers immersed when the
electro-magnet should act. Figures 8 and 9 shew a suitable arrangement in
which the cover (M) has, instead of the finger piece, a friction roller (k) on which
on a spindle (m) and connected to said spindle by
one
The spindle is provided at
end with
coiled spring (0).
handle (p) and has a ratchet or other escapement for preventing its
turning, except in one direction. The cam (1) may be momentarily
checked in its movement by a spring (t). The entire device would be enclosed
in a case leaving only the handle (p) exposed. Supposing the circuit to be
broken, as shewn in Figure 8, in order to close the circuit the handle (p) is
turned, the cam (7) being momentarily arrested by the spring (t) not partaking
in this movement. The coiled spring (o) is thus put in tension until it over-
comes the resistance of spring (t) whereupon the cam (/) will be caused by the
action of spring (o) to describe a complete revolution without its movement being
prevented by the handle the cam (7) in rotating, closing the cover (M) by means
of roller (k) and closing the circuit. On the other hand the circuit may easily
be broken by raising cover (M) by means of a lever. In the case of a multiple
switch the cam (1) would be arranged to act on several apparatus successively.
Dated this 29th day of January 1898.

page_text: I, MAURICE BOUCHET, of 22, Rue Alphonse de Neuville, Paris, France, 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:-
My invention relates to apparatus for automatically breaking an electric circuit
when the current exceeds a certain intensity. My improved circuit breaker can
either be operated by hand or from a distance and may also be employed as a
switch.
Reference is to be had to the drawings accompanying my Provisional Speci-
fication wherein Figure 1 represents a vertical section of the apparatus, the
circuit being closed. Figure 2 is a transverse vertical section on line 1-2
Figure 1. Figure 3 is a horizontal section on line 3-4 of Figure 2. Figure 4
is a vertical section of the apparatus, the circuit being open or broken. Figure 5
is a modification. Figure 6 is a vertical section of a modification. Figure 7
shows the apparatus applied as a bi-polar circuit breaker. Figure 8 represents
the apparatus as provided with a safety device. Figure 9 is a horizontal section
on line 5-6 Figure 8. The same letters of referenco denote like parts in all the
figures.
My improved circuit breaker consists essentially of a container (A) of porcelain
or other insulating material provided with two cavities (a), (b), sepa-
rated by a partition (c) and containing mercury up to the level (n),
(Figure 4). Each cup (a), (b), is in communication with one of
the poles of the circuit and in the case of Figure 4 all passage
of the current is prevented by the partition (c). A block (B) of insulating
material forming a pair of plungers of suitable form is disposed above the cavi-
ties (a), (b), and is capable of being lowered into the same so as to raise the
level of the mercury to the level (¹) above the top edge of the partition (c) so
as to establish electrical communication between the two chambers (a), (b) (see
Figures 1 and 2). On raising plunger (B) the mercury returns to its original level (n)
in chambers (a, b) as shewn in Figure 4, and the breaking of the circuit is produced
in the liquid itself without burning any contact piece, and further the formation of
an arc is prevented, owing to the interposition of the insulating partition between
the two poles of the circuit. The plunger (B) is attached to the core (d) of an
electro-magnet supported on the mercury container (A) by means of a screw
having an insulated head, a washer (r) of elastic and insulating material being
interposed between said core and the plunger B.
The electro-magnet may be of any type but preferably I employ a special
arrangement of electro-magnet composed of three parts of magnetic material, viz.
a part (D) forming one cheek of the bobbin and provided with a polar tubular
extension piece, which while serving for the passage of the lines of force con-
siderably diminishes the reluctance of the interferricum gap; a part (E) forming
the other cheek of the bobbin and provided with a polar extension (e) of decreas-
ing section; a sheath (C) uniting the parts (D) and (E). When no current
passes through the electro-magnet, the core occupies the position represented in
Figures 1 and 2, corresponding to a closed circuit. The reluctance of the inter-
ferricum gap being relatively feeble and that of parts (D) and (E) but trifling,
the action of the ampère turns developed in the coil is directed upon (e) where
the effect is then very powerful. The magnetic flux tends to cause the progres-
sion of the core for increasing the section of passage of the lines of force. The
force exerted between two points of movement of the core will depend upon the

page_text: increased section offered to the flow between these two points. Thus by adopt-
ing a suitable shape for the extremity (e) of part (E) the force acting on the core
may be rendered constant. The core (4) is surmounted by a non-magnetic metal
rod (d) sliding freely in the head (E) and is also guided by a disc or washer (R)
placed beneath the head (D). This disc or washer, which is made of insulating
material protects the electro-magnet from all contact of the mercury and forms a
tight joint with the flange of vessel (A).
(M) is a cap or cover for the apparatus provided with a finger piece and which
may be pivoted at (J) in bearings (S) screwed to the sheath (C). The cover (M)
is jointed to the rod (d) so as to partake in the movements of the core (d) and
plunger (1). (P) is a spring jointed at the one end to the pin (1) on bear-
ang (S) and at its opposite end to cover (M) said spring serving to hold the cover
down when the core d is in the position corresponding to closed circuit and to
raise the cover entirely off when the electro-magnet commences to act, the cover
being forced by the spring to pass suddenly from one position to the other,
which movement is effected by placing the pin (G) of the spring below a line
drawn through (J), (J). The inclination of the cover (M) and consequently the
position of axis (G) relatively to the line (J), (J¹) is regulated by an adjusting
screw for enabling the sensitiveness of the apparatus to be modified. This sen-
sitiveness of the apparatus may also be obtained with the aid of counterweights
balancing the action of the electro-magnet. In this case the spring simply serves
to continue the movement commenced by the electro-magnet and hold the
cover (M) raised.
The current arrives by the terminal (f), (Figures 2 and 5) which is electrically
connected to the mercury cup (a) by screw (9). The other cup (6) is connected
to the electro-magnet coil by the wire (h). The opposite end of the bobbin is
connected to the terminal (2) by the wire (j).
Supposing the apparatus to be in the position shewn in Figure 4, by press-
ing on cover (M) the core (d) and plunger (B) are caused to descend and the two
members of the latter to dip into the cups (a), (b) of the mercury container,
whereupon the level of the mercury will rise above the separating partition (c)
and the cups (a) and (b) will be put in electrical communication and the circuit
closed. Should the intensity of the current exceed the desired limit, the force
exerted upon the core (d) overcomes the resistance of spring (P) and core (d) is
attracted, the spring (P) continuing the movement and maintaining the core (d)
and plunger (B) completely raised, the circuit being then broken and the two
cups being no longer in electrical communication. The insulating partition pre-
vents the forming of an arc and the breaking of the circuit being effected, so to
speak, in a closed vessel no alteration of the mercury can take place, it being
possible to place the apparatus in an explosive medium and break the circuit
without any risk of sparking. When the apparatus is raised, as shewn in
Figure 4, the elastic washer (r) abuts against the insulating washer (R) and
makes a tight joint. The apparatus might even be inverted without any of the
mercury escaping.
The wire of the electro-magnet is calculated so as to introduce into the circuit
only a negligable resistance. In the case of alternating currents the metallic
parts of the electro-magnet would be suitably divided for diminishing induced
currents.
The current leads to the mercury cups may be so disposed as to be out of con-
tact with the mercury when the plunger (B) is raised. The lower ends of the
conductors will thus, as shewn in Figure 5, be above the level of the mercury
when plunger (B) is raised. The action of the plunger is to first put the mer-
cury in each cup in communication with its conductor and then the two cups
with each other. Inversely the breaking of the circuit is only produced between
the two cups at the top edge of the partition (c) between two molecules of mer-
cury and never between the mercury and the leading-in wires.

page_text: The apparatus would be mounted upon a backing of insulating material.
The vessel (A) may be provided with any suitable number of cups so that the
two extreme compartments (a), (b) into which lead the conducting wires, may be
separated by one or several cups (see Figure 6).
Two of these apparatus may be placed side by side so as to constitute a bi-polar
circuit breaker (see Figure 7). in this arrangement the terminals are repre-
sented as placed at different levels so as to avoid the crossing of the wires sup-
posed to be covered by casings. The two apparatus may be arranged so as to
both break the circuit at one time by the action of a single electro-magnet, by
providing on the cover (M) of the one apparatus a lug which abuts in rising
against the teeth of a small fork mounted on the cover (M) of the other appa-
ratus, the play between the parts only permitting the apparatus to act mutually by
the action of the spring (P) so that the electro-magnet will have no extra load to
overcome. The same arrangement would be employed for circuits of three or
five wires.
The apparatus may be used both as a switch and as a circuit breaker operated
by hand, the cover (M) being raised or lowered by hand in the one case and
automatically operated in the other if the current exceeds the proper limit. With-
out the electro-magnet it forms a simple switch possessing the advantages before
described when used as a circuit breaker.
It will be evident that the apparatus may be used as a switch at a distance for
various purposes, such as for tramway contacts, rheostats, etc., it being only
necessary to insulate from the main circuit the circuit of the electro-magnet and
to control the latter from any point.
The apparatus may also be used to limit the supply of current in a subscriber's
circuit for example. In this case it is indispensable that the apparatus should
not be capable of being tampered with by keeping the plungers immersed when
the electro-magnet should act. Figures 8 and 9 shew a suitable arrangement in
which the cover (M) has, instead of the finger piece, a friction roller (k) on which
acts a cam () mounted loosely on a spindle (m) and connected to said spindle by a
coiled spring (o). The spindle is provided at one end with a handle (p) and has a
ratchet or other escapement for preventing its turning, except in one direction. The
cam (7) may be momentarily checked in its movement by a spring (t). The entiro
device would be enclosed in a case leaving only the handle (p) exposed. Supposing
the circuit to be broken, as shewn in Figuer 8, in order to close the circuit the
handle () is turned, the cam (1) being momentarily arrested by the spring (t)
not partaking in this movement. The coiled spring (o) is thus put in tension
until it overcomes the resistance of spring (t) whereupon the cam (/) will be
caused by the action of spring (o) to describe a complete revolution without its
movement being prevented by the handle, the cam (4) in rotating, closing the
cover (M) by means of roller (k) and closing the circuit. On the other hand the
circuit may easily be broken by raising cover (M) by means of a lever. In the
case of a mutiple switch the cam (4) would be arranged to act on several appa-
ratus successively.
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:
1. An electric circuit breaker or switch consisting essentially of a vessel con-
taining two cavities separated by an insulating partition and each containing
mercury to 2 common level lower than the top of the partition or
than the bottom of an orifice in the partition, so that by the rise
of the mercury level to a sufficient height electrical communication will
be established between the two masses of mercury and the conductors connected
therewith and by a fall of the mercury to its normal level the breaking of the
circuit will be effected between the masses of mercury the formation of any arc
being prevented by the partition,

page_text: 2. In an electric circuit-breaker or switch comprising two mercury chambers
separated by a partition and capable of being put in electrical communication by
the rise and union of the two masses of mercury above or through the partition,
the conductors led into the chambers so as only to be in electrical communication
with the mercury when the latter is above its normal level, the rise of the mer-
cury first closing the connection between it and the corresponding terminal and
afterwards between the two masses of mercury so that the insulating partition is
not subjected to any electrical tension whilst the circuit remains broken.
3. The herein described electrical circuit breaker or switch comprising any
number of mercury chambers separated by insulating partitions, and capable of
being put in electrical connection by the rise of the mercury level as described,
the leading-in wires or conductors being contained in the extreme end chambers.
4. An electric circuit-breaker or switch as herein described in which the change
of level of the mercury in the chambers relatively to the insulating partition is
produced by means of displacing plungers moved up and down together as one
and operated by hand in the case of a simple switch.
5. An electrical circuit-breaker, or switch as herein specified in which the
vertical movement of the displacing plungers is produced by an electro-magnet
energized by the current or a part thereof so as to constitute a magnetic circuit-
breaker or placed in an independent circuit so as to be operatable from a
distance.
6. An electrical circuit-breaker or switch as specified in which the displacing
plungers are caused to pass suddenly from one position to the other by a spring
or counterweight.
7. An electrical circuit-breaker or switch as herein specified in which the
electro-magnet comprises three magnetic parts:-
-
(1) a part D forming one cheek of the coil having a tubular polar expansion
which in giving passage to the lines of force gradually diminishes the
reluctance of the interferricum gap;
(2) another cheek E having a polar expansion c of decreasing section;
(3) an armouring C connecting parts DE.
8. The adaptation of the herein described electrical circuit breaker or switch as
above specified for limiting the supply of current in a subscriber's circuit, the
apparatus being provided with means for preventing the switch being kept per-
manently on "and for moving it to the on position when the circuit is
broken.
"
"
9. The combination of two or more of the herein described electrical circuit-
breakers as above specified to constitute a uni-polar, bi-polar, or multi-polar circuit
breaker as specified.
Dated this Ofth day of Antahan 1808