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Патент USA US2130999

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Sept. 20, 1938.
RMICHL
2,130,999
Z9
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5”
QPJMW
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Sept. 20, 1938. ,
F. PET-ERMICHL
2,130,999
ELECTRIC CIRCUIT INTERRUPTER
Filed Feb. 15, 1937
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3 Sheets-Sheet‘2
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Inventor :
F‘T'amz peter'rnichl,
His Attorney.
Sept. 20, 1938;
F. PETERMICHL . '
Filed Feb. 15, 1937
2,130,999
I
s Sheets-Sheet s
33
nsulatio‘n
1I
3 Z0
I‘?venbov.
Franz ‘Pebewvmic'hl,
w x/
54W
M745 Abtovneg.
Patented Sept. 20, 1938
' 2,130,999
UNITED STATES PATENT OFFICE.
2,180,999
ELECTRIC CIRCUIT INTERBUPTER
Franz Petermichl, _Berlin-Charlottenbnrg, Ger
many, assignor to General Electric Company,
a corporation of New York
'
appucauon February 15, 1937, Serial No. 125,919
-
In Germany February 28, 1936
6 Claims.- (Cl. 200-149)
My invention relates to electric circuit inter
back is obviated in a simple manner by dividing
rupters of the expulsion type wherein an arc-ex
up the quenching channel which isformed by ‘gas
yielding materials and through which the contact
point of the movable contact is drawn when open
tinguishing gas is generated upon opening of the
circuit by the action of thearc on a material close
ly con?ning or in direct contact with the arc. The
gas so generated is suitably directed so as. to cause
interruption of the arc.
‘
More particularly, the invention is concerned
with an electrical switch wherein the arc is
D quenched by means of pressure gas. The gas is
liberated by the arc to be interrupted in ‘a switch
tube, which consists of rigid materials adapted to
ing the circuit, in such a way that adjoining the 5
?xed switch contact there is an arc quenching’
channel structure whose length is dimensioned for
the interruption of large currents. The channel
then comprises an intermediate expansion or
blow-out chamber wherein the large currents are 10
interrupted. A further quenching channel is in
communication with the expansion chamber and
emit gas under the in?uence of heat, or is lined , its length is so dimensioned that it produces to
with such materials. More speci?cally, in a pre
ferred form of my invention the contact point of
the movable switch member, from which the arc
extends to the ?xed or counter-contact after con
tact separation, is moved directly through an arc
quenching passage or channel wherein the arc
U
gether with the ?rst quenching channel structure
the requisite length of switch tube for certain 1‘
quenching of the arcs of small currents. The in
termediate expansion or-blow-out chamber can be
closed except for the passage openings for the
movable switch member. It can, however, also be
quenching gas is produced by the contact of the
vented to the surrounding air by means of an ex- 20 '
arc with the inner gas-yielding walls of the pas
haust passage extending to the blow-out end of
the switch tube, or by means of openings provided
in the switch casing. Under certain circum
stances as hereinafter described it may be expe
dient to arrange valves in those openings.
25
My invention will be more fully set forth in the
following description referring to the accompany
sage.
,
In each case the quantity of liberated arc
quenching gas depends on the intensity oi’ the our
5 rent to be interrupted, on the size of the surface of
the switch tube in contact with the are and on the
duration of the arc. Consequently, in order to
produce the quantity of gas required for the
quenching of small currents, it is necessary to
J use a longer switch tube than for the quenching
process of large currents. However, a long switch
. tube, dimensioned for the quenching of small cur
rents, works out unfavorably when switching of]!
large currents. That is, since the quenching, of
5 thearc is generally e?ected directly when the
contact point of the movable ‘switch member un
ing drawings, and the features of novelty which
characterize my invention will be pointed out
with particularity in the claims annexed to and 30
forming a part of this speci?cation. ,
Referring to the drawings, Fig. 1 is an elevation
al, sectional view of an electric circuit breaker em
bodying the present invention, and Figs. 2 and 3
thereby releases a quenching blast, the burning
are similar views of other forms my invention may 36
assume.
The switch as shown in Fig. 1 is constructed in
accordance with the invention and consists es
duration of the arc . is unnecessarily prolonged
sentially of two tubular pieces I and 2 of gas
) when switching o?- large currents. During this
entire additional period, ‘however, the insulating
within a supporting sleeve or casing 3. The cham
material linings and the switch contacts are sub
ber so formed between the same comprises an ex
covers the blow-out end of theiquenching tube and
yielding insulating material, which’are spaced 40
jected to great stress by the powerful arcs, with
out aiding the actual quenching process.
pansion or blow-out chamber 4. Inthe con
structional example, an exhaust channel 5 vents
5
The result is a greater wear and deterioration of the intermediate channel or expansion chamber 45
the gas-yielding material and of the contact ma- ' 4 to the blow-out end of the switch tube, at the
terial, and also excessive and unnecessary stress opposite closed end of which the ?xed contact 6
upon- the arc chambers by the pressure of the is arranged. 'This contact coacts with the tube
heated gases produced by the arc.
shaped movable switch member 1, into which a
)
A'principal object of the present invention is the bolt 8 of insulating material projects from the 50
provision of an improved circuit interrupter of the base of sleeve 3. The members I, 2 and 8 are com
aforesaid type which is e?icient, reliable and posi
posed ‘of a suitable gas-yielding material such as
tive in operation throughout the entire range of, fibre and closely con?ne the arc during the in
its interrupting capacity.
;
,
According to my invention, the aforesaid draw
terrupting process.
.
When switching of! large‘ currents, considera- u
.2
arouses
ble quantities or" gas are liberated from the insu
lating tubular structure I! by the are. Directly the
contact point or tip of the movable contact 7
leaves the structure l , a quenching stream of gas
is released and directed as indicated in the direc
tion of the expansion chamber ll, owing to the
pressure difference between the compartment en
of the extinguishing tube at the ?xed switch con-‘
tact, of single plates, which are arranged in
cornpassing the ?xed contact
layers with the interposition of spacers
and the expansion.
Aper
chamber fl. _ As a result of this gas blast the arc
tures are provided in these plates, =.
is quenched, without ice-ignition.
into a suitably positioned discharge duct.
mode of execution according to this aspect
of the invention, in the application to gas expul~
sion switches wherein the switch tubes consist
of a cylindrical part with concentrically inserted
bolts of insulating material, and the movable
the arc during
the further course of the switching-off stroke of
the movable switch member, by reason. of the fact
that the gases still remaining under pressure in
the tube i and in the intermediate chamber ll
insulate the, contact
the recovery voltage.
Heavy current arcs are therefore interrupted be
fore the contact '1 enters the tube
On the other hand, when interrupting small
currents, the quantity of quenching gas liberated
20
within the spaces forming the expansion cham
ber. During this operation the movable switch
member keeps the exhaust end of the extinguish
ing tube closed.
It is especially advantageous to make the end
the are from the ?rst inst
ng tube is so
'1 open
switch member consists of a'tube contact, as in.
the case of Fig.
has the following material
advantage.
It has been observed that in tube
contacts, the base of the are at the lower contact
edge heats up the metal. of the contact to its
slight that it does not suirlce
the quenching
of the arc and insulation
respect to the
recovery voltage. Instead the are is drawn
fusion point, and that the extinguishing gas di»
rested in the direction of the circuit opening
movement blows the fused particles of the con
through the intermediate chamber d and con- ' tact into the narrow gap between the tube con“
25 tinues within the tube 2. Accordingly the devel
tact and the walls of the switch chamber.
opment of gas increases to such an extent that Thereby the surface of the tube contact is given
the main quenching blast set up upon emergence a rough coating which upon hardening has a
of the movable contact 'i from the exhaust open
destructive effect on the walls of the extinguish“
ing of the switch tube causes the arc to be ing tube particularly when switching on again.
30
quenched.
in the arrangement according to my invention
arcs of great current inten 4"
therefore
quenched more quickly than
'herto. Conse
quently the wear'and deterior .uori of the switch
parts under the in?uence or" the arc and the
stress upon the parts exposed
the pressure of
the switch gases are less than they were hitherto.
rfhis limiting or” the arc duration in the case of
large currents is of especial importance in con—
40 nection with the contact wear tor the reason. that
the metal parts which are greatly heated~ up in
the ?rst'half-cycle of the
are thereafter sub
ject to greater deterioration.
wear in=
creases in a far greater progression than corre
sponds with the are duration.
A further advantage of the arrangement ac
cording to my invention is that the hot gases
produced when switching off large currents are
not conducted directly through the tube 2 which
is utilized for the quenching or the small cur
rents.
The gases are instead cooled in the inter“
mediate compartment ll through expansion, so
that only the tube l is essentiallyr subjected to
wear due to heavy ‘current arcs.
Consequently
At the same time, however, a breach or depression
originates naturally in the edge of the tube com
‘tact at the base of the arc. "Upon the next
switching operation the base of the arc is driven
upwards to the edge of the tube contact under
the in?uence of the extinguishing gas current,
until it comes to rest at the breach, and the
process described above is repeated with the
.result that the
becomes deeper and
deeper, and a very uneven biu'nir g of the tube
contact ‘takes place, whi h therefore
repaired prematurely.
Ti‘his disadvantage
be
overcome by the present
form of the invention, since the direction of the
gas blast, as long as the tube contact l ens the
exhaust end of the
tube closed, will be
essentially opposed to the direction of movement
of the tube contact.
Finally, according to this aspect of the lnven~
tion, the apertures in the plates forming one end
of the extinguishing passage can be displaced
opposite each other, as for example along a spiral
path. By this means the points of the are which
are subjected to the strongest transversal blast,
i. e. in the air pockets or expansion spaces be
when switching off large currents, the‘ chamber
will remain better suited to the interruption of
tween the single plates of the insulating gas
yielding material, are displaced spirally in the
small currents than ‘would a chamber, without
an arrangement according to the invention,
which is subjected to wear along its entire length
promoting the extinguishing of the arc, is
when switching off large currents‘.
In certain circumstances it may be expedient
Referring more particularly to Fig. 2, 2i indie
to make the tube structure i of more than one
piece of gas-yielding material such as of individ
ual plates provided with bores and stacked in,
spaced layers. The expansion chamber is
formed by the spaces between the plates. Fig. 2
illustrates such an arrangement.
I
'As in the previous case the object consists in
‘guaranteeing safe extinguishing of the are not
70 only at highand low current values but also at
critical medium current intensities. This object
is attained in'the present case by so constructing
the switch tube adjacent the ?xed switch contact
of gas-yielding material that the arc is subjected
75 to a transversal blowing and lengthening thereof
same manner.
attained.
"in this way rotation of the arc,
’
cates the switch chamber, which surrounds the
?xed tulip-shaped contact 22 and cooperates
with the movable tube shaped switch contact 23.
The switch chamber is formed by a generally tu
bular structure made of insulating material ca a.
pable under in?uence of the arc of giving oil? gas.
The tubular structure comprises an integral tube
24 at the exhaust end, and single ‘discs 25 in the
region of the ?xed contact 22. The discs 25,
which have centrally alined apertures for the
contact 23, are spaced by members 26, and to
gether with the fixed tube 24, form a continuous
passage for the passage of the movable switch
tube 23. Within the passage 2. bolt 21 of insu~
lating
material,
appropriately, of
material
3
2, 180,999
adapted to give o? gas, is arranged concentrical
ly. The bolt 21, positioned centrally of the con
tact tube 23, is ?xed to the cover 23, which in
the form shown by way of example, surrounds
the ?xed contact 22 and also the end of the ex
tinguishing tube formed by the discs 25.
,Apcrtures 25’ are provided in the discs 25 and
are arranged in superimposed position, as shown,
or displaced with respect to each other. The
) extinguishing gases exhausting through the in
termediate spaces forming the expansion cham
ber between the plates and through the aper
tures 25, can escape freely through passages 24'
in the tube 24.
5
‘
Under certain circumstances for attaining as
powerful a transverse blast between the discs as
possible, a packing 23' can to advantage be lo
cated in the ?xed tube 24 for preventing initial
exhaust of the extinguishing gases along the tube
6‘ contact 23, as long as the contact is within the
into the intermediate expansion chamber, in ac
cordance with the strength of the current to be
switched o?.
'
-
These di?lculties are obviated, in accordance
with the present form of my .invention by sep
arating the intermediate chamber, preferably in
direct communication with the outer air, from
the gas-forming chamber proper, by an auto
matically operating valve, such as an annular
slide valve, for bridging the space between the 10
two gas-yielding tube-pieces.
In accordance with the interrupting condi
tions, the annular slide-valve opens more or'less
in response to one component of the compressed
15
gas in opposition to the force of a spring.
With a development of this kind, the small
currents .also, are reliably quenched by the gas
?ow, as the movable switch rod passes out of the
first part of the quenching tube. Surprisingly,
a phenomenon, favorable to the voltage arc 20
quenching, is that the arc voltage is slight, both
when switching-out small as well as great cur
the interior or the-recessed cover 28, projections rents. Besides this a further advantage is that
28' for retaining the plates 25 and their spacing the annular slide also can if desired be made
;5 rings 26. The plates and rings are held'in this , of gas-yielding material, although advantageous 25
extinguishing’ tubes. A simple assembly of the
switch chamber is also possible by providing in
position by screwing the fixed insulating tube
24 into the cover 23 as shown.
The manner of operation of the gas expulsion
switch according to the present form of my in
;0 vention, is as follows:
The arc l3, which is drawn between the con
‘Wtacts 22 and 23 upon switching off immediately
develops extinguishing gas from the gas-yielding
walls at 25. This gas is under pressure as com
;5 pared with the surrounding ,. air. The result is
that the arc is driven into the intermediate ex
pansion space between the plates 25 and under
goes considerable lengthening, so that its resist
ance is weakened.‘ Since at this time the path
40 through the exhaust end of the extinguishing
tube is entirely or for the most part blocked
ly of a somewhat less readily vaporizing material,
and can thus be utilized for developing quench
ing gas.‘
.
Referring more particularly to Fig. 3, the
unching chamber of the gas-switch is formed 30
by the two pieces of tube 3| and 32 which are
composed of a material adapted to give of! gas
under the in?uence of the arc, and which are
spaced in a supporting body 33. At one end of
the tube 3| is provided the fixed contact 34, which
cooperates, in the embodiment shown by way of
an example, with the movable 'tubular switch
contact 35. A bolt 36 of insulating material,
preferably of gas-yielding material, extends into
the contact 35 from the closed end of the sup
porting body 33. The chamber 31, disposed be
against the extinguishing gases, they necessarily tween the tubes 3| and 32, is in communication
‘?ow through the intermediate spaces between the vwith the outside air, directly or indirectly,
plates, through the apertures provided therein,
45 to the discharge passage in the fixed extinguish
,ing tube 24. A, powerful transverse blast is
therefore directed through the are at several
places at the same time.
-
The combined action of both these phenomena,
50 practically insures together with the later main
extinguishing blast at the exhaust of the ex
tinguishing tube, a safe extinguishing of the arc
for both small and medium currents as well as
with large current. As in the case of Fig. 1 small
currents are readily interrupted within the.
55
tube 24.
_
.
The dimensions of 'the apertures 25' and of
the passages 23' must of course be chosen in
such a manner, that upon the extinguishing of
[30 large currents, notwithstanding the direct con
nection with atmosphere, an adequate extin
guishing pressure can build up in the switch tube.
through apertures 38.
-
_
In accordance with my invention, an annular
slide valve 39 is mounted on the tube-member
32 and is under the in?uence of a spring 3|].
The valve is provided with a pressure-surface
39' which is acted upon by the switch-gases, and
is of suitable form, as a conical turned-down part,
for instance.
In its closed or normal position,
it seats on the casing 33 carrying the tube-mem
ber 3|. The annular slide 33 may also consist
of gas-yielding material and may, of course, if
desired be guided on the other tube-member 3| 55
or in the walls of the casing 33.
The operation of this form of the gas-switch,
in accordance with my invention is as follows:
On switching off a current of any magnitude,
a quantity’ of quenching-gas is first freed from
the tube-member |. The gases so developed un-‘
der pressure move ‘the slide 39 more or less away
Fig. 3yillustrates an arrangement fundamen
from the casing 33 and a blast ‘takes place
tally similar to Fig. l and comprises an improve
through the annular gap so formed, into the in
ment in a gas expulsion switch of this kind. It > termediate or expansion chamber formed by the 65
has become evident, that the cubic contents of casing 33. This blast quenches the arcs of great
the intermediate or expansion chamber must and also of comparatively small or medium cur
be sufficiently great for the generation of an
adequate blast forthe quick quenching of large
0 current arcs and that, on the other hand, when
the intermediate chamber is restricted in volume,
smaller currents, even at higher voltages, can be
better interrupted. These requirements, opposed
to each other, can be met by providing valves
5 which regulate the inlet of the quenching gases
rents.
'
With quite small currents, on the‘other hand, 70
the slide 33 remains closed so, that the arc pas
sage is restricted and the gas formation, requi
site for the switching-off of these currents, pro
ceeds unhindered until the contact point of the
movable switch member leaves the quenching
arouses
‘tube. At this point, the exhaust lolast effective
ly interrupts a lingering are.
can subsequently be drawn, said plates and cyl
lit should be understood that my invention is
not limited to specific details of construction and
arrangement thereof herein illustrated, and that
changes and modi?cations may occur to one
skilled in the art Without departing from the
spirit of my invention.
‘it/‘hat I claim as new and desire to secure by
Letters Patent of
.c13
States
1. An electric circuit interrupter
the gas
expulsion type comprising relatively movable contacts, and a casing including insulating struc
ture for substantially enclosing
con?ning the
are formed at said contacts along
substan
tially longitudinal path upon opening of the cir~
cult, said casing betig closed at one end at which
initial. contact separation takes place, said in»
sulating structure forming adjacent said closed
end an expansion chamber arranged directly to
he vented to a low pressure area for the inter
ruption of comparatively large currents and a
restricted longitudinal passage adapted. to com
municat/e with said expansion chamber, the arc
» formed at said contacts being initially drawn
through said expansion chamber and subsequent
ly iii the case of a persisting are through said
said arc,.spaces between said plates being vented
to atmosphere independently of
restricted
bore so that the gas pressure generated upon
initial. formation of said arctends to force said
are laterally between said. plates.
'
An electric circuit interrupter, of the gas
expulsion type comprising relatively movable con
tacts, and insulating stru Sure arranged to form
con?ning passage for ‘- 1e arc drawn between
said contacts upon opening of the circuit, said
insulating structure adjacent one of said con-1
tacts closely con?ning in. sleeve-like relation the
arc
the initial formation thereof and at a
point remote from said contact consisting of a
cylindrical member likewise closely confining said
arc, said con?ning passage including an expan
sion chamber vented to atmosphere interposed
between said cylindrical passages, said insulating
structure at said passages being composed of a
material adapted to emit an arc~extirwuishing gas
When
5. An
subjected
electric to
circuit
said are.
interrupter of the expul
sion type comprising relatively movable contacts,
restricted passage, said insulating structure ad
insulating structure arranged to form a confining
jacent to the point of initial formation of said
passage for the are drawn between said contacts
are in said expansion chamber and in said re
upon opening of the circuit, said insulating struc
ture adjacent one of said contacts consisting of
stricted passage being composed of a material
adapted to emit an arc-extinguislung gas When
subjected to said arc.
2. An electric
interrupter of the gas
expulsion type comprising a ?xed contact, a co
spaced plates having substantially aliuecl aper
tures through ‘which said are is dravm, said plates
also having apertures interconnecting the spaces
between said plates, said insulating structure also
acting movable contact, and a casing including
insulating structure for mounting at one end
thereof said fixed contact, said
being closed
comprising at a point remote from said contact
a cylindrical member having
bore restricted
at said end, said structure arranged to form a
which said are car; subsequently be drawn, said
plates and cylinder being c
‘nosed of material
con?ning substantially enclosed passage tor the
are between said contacts upon opening of the
circuit, said passage being enlarged adjacent said
with respect to the other?
adapted to
contacts through
an arc-extinguishing
when
subjected to said
5. An electric circuit interrupter of the expul
?xed contact to form an expansion chamber ar
ranged to have a direct exhaust to atmosphere,
sion type comprising relatively movable contacts,
" being restricted with respect to said movable
co: ct at a point remote from said 1 seal contact,
and insulating structure for confining the are
formed at said contacts upon opening of the cir
said insulating structure immediately adjacent to
cuit, said insulating structure defining an ex
pansion chamber adjacent the point of initial
separation of said contacts and also including a
cylindrical member for ‘defining restricted pas
said ?xed contact being composed of material
adapted to emit an arc-extinguishing gas when
subjected to said arc.
3. An electric circuit interrupter of the gas
:1 LI
inder being composed oi’ a material adapted to
emit an arc-extinguishing gas when subjected to
expulsion type comprising relatively movable con
tacts, and casing including insulating structure
sage in communication with said expansion
chamber through which the are can subsequently
be drawn, one of said contacts being movable
arranged to form a con?ning passage for the are
through said-restricted passage, said expansion
drawn between said contacts upon opening of the
circuit, said casing adjacent one of said contacts
enclosing a plurality of spaced plates having sub
chamber being vented to exhaust at a point ad—
jacent the exhaust of said restricted passage in
dependently of said restricted passage, said in
sulating structure including in part a material
adapted to emit an arc~eirtiziguishiug gas when
subjected to said are.
stantially alined apertures through which said
are is drawn, a cylindrical member having a
s1eeve~1ilre bore restricted with respect to the
other of said contacts through which said arc
FRANZ PETERBMCHL.
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