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Патент USA US2134506

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Oct. 25, 1938.
H. BUCHWALD ET AL
ELECTRIC CIRCUIT INTERRUPTER -
2,134,506’
Oct- 25, 1938.
H. BUCHWALD Ef AL
2,134,506
ELECTRIC CIRCUIT INTERRUPTER
Filed June 10, 1935
Sheets-Sheet 2
Inventors:
- -
Herbert Buchwald,
Erwin Marx,
by
X] l
.T heir) Attonneg. _
Patented Oct. 25, 1938
v 2,134,506
UNITED STATES PATENT OFFICE
2,134,506,
_
ELECTRIC omcorr INTERRUPTER
Herbert Buchwald, Berlin-Reinickendorf, and Er
win Marx, Braunschweig, Germany, assignors to
General Electric Company, a corporation of
New York
Application June 10, 1935, Serial No. 25,904
In Germany June 12, 1934
5 Claims.
(Cl. 200-—,148)
The invention relates to electric circuit inter
rupters, more particularly to circuit interrupters
of the gas-blast type wherein a jet of gas or ?uid
from a suitable source of pressure is utilized for
interrupting arcing upon opening of the circuit.
:1
Heretofore in extinguishing the arc upon open
ing of the circuit by gas or a ?uid such as air
under pressure, the ?ow of gas was so adjusted
that an intensive cooling of the arc was obtained.
It has likewise been proposed to increase the arc
extinguishing effect by locating both bases or.
roots of the arc at so-called arcing tips which
areseparate from the contact making parts.
Whatever favorable effect these arcing tips have
15 on the interrupting capacity of the circuit inter
rupter is mostly attributable to the fact that
they oppose, to a limited extent, the gases flow
ing from the actual arc chamber. This fact has,
however, not been recognized prior to the present
20 invention.
The main object of the present invention is an
improved method of circuit interruption and the
correct formation of the electrode and contact
structure in circuit interrupters of the aforesaid
25 type for increasing the effectiveness of the arc
interrupting gas blast.
_
For an understanding of the nature of this in
' vention, consideration of the following principles
is necessary.. If the are upon opening of the
30 circuit is to be extinguished with the minimum
of trouble, that is with the smallest quantity of
gas at comparatively low gas pressure, care must
be taken that during the arcing period and until
the passage of the arc current through zero the
35 arc developsv the smallest possible amount of
heat in the arc chamber. To this end it is neces
sary that the voltage drop across the arc be
kept as small as possible during the main arcing
period.
4O
The are should, therefore, notbe im
concentrated jet must be completely dissipated.
This result is not effected at all or in any event
only to a very small extent by previously known
forms of arcing tips.
In the case of these arcing tips, there is fur
ther the possibility that the points of the base
of the arc will not remain at the ends of the
arcing tips, but will be driven by the gas ?ow
longitudinally along the sides thereof so that
undesirable lengthening of the arc results. This
possibility is likewise preventedby rapidly de
fleeting the gas flow in the radial direction as
above described.
-
The invention will be more fully set forth in
the following description referring to the accom
panying drawings, and the features of novelty
which characterize our invention will be pointed
out with particularity in the claims annexed to
and forming a part of this speci?cation.
Referring to the drawings Fig. 1 is an eleva
tional view partly in section illustrating diagram
matically a form of our invention wherein the
electrode structure is shown in the open circuit
position; Fig. 1a is a similar view showing the
electrode structure in the closed circuit position;
‘Fig. 2 illustrates another form of our invention
wherein the electrode structure is shown in the
open circuit position; Fig. 2a is a similar view
showing the electrode structure in the closed cir
cuit position; Fig. 3 is an elevational sectional
view of an electric circuit breaker of the gas blast
type having incorporated therein the electrode.
structure shown by Figs. 1 and 1a.
In accordance with this invention one or more
de?ecting bodies are positioned so as to oppose
the gas ?ow with respect to the longitudinal axis,
and are so formed that they likewise change the
direction of gas ?ow. Furthermore, the eddies
in the gas ?ow which cannot be avoided along the
axis of the electrode arrangement and its im
moderately lengthened. Furthermore, it should
be subjected only to the smallest possible trans ' mediate surroundings with the sharp de?ection
verse blast, that is, to a gas jet at right angles
to the longitudinal axis of the arc. To this end
it is primarily necessary that the velocity of the
45 gas flow beyond the exhaust openings, such as
in hollow or ring-shape electrodes, be reduced
as rapidly and as much as possible. This cannot
be effected solely by enlarging the cross-sectional
?ow.
For this purpose, in accordance with the pres
ent invention, a comparatively great de?ection of
the direction of ?ow is necessary. In the usual
case the gas ?ow is through the hollow electrodes
in an axial-direction. It must be deflected back
55 in approximatelyradial direction, that is, the
of the ?ow are, under certain circumstances, even
made advantageous. For the purpose of de?ect
ing the gas flow in accordance with this inven
tion, the surface of the de?ecting body opposing
the gas flow may be either ?at, concave or con
vex in any suitable form.
1
Referring more particularly to Fig. 1, there
are illustrated at the upper and lower hollow
electrodes l and 2, respectively, different forms
by way of example, of the above described deflect
ing body. The electrodes I and 2 may be ?xed
in spaced relation, such as in a lightning arrester,
or may be relatively movable such as in circuit
breakers for example.
Fig. 1a illustrates the
2
2,184,506
electrodes in the closed circuit position when
operating as a circuit breaker.
The de?ecting body 3 associated with the elec
trode 2 is of large diameter as compared with
the passage 2' through the electrode 2. The de
?ecting surface at 3' may be made concave or
convex in accordance with the particular design
of the electrode structure.
The de?ecting portion 4 which is associated
with the electrode l is of slightly smaller diam
eter than the passage 2' in the electrode 2. The
electrode I is provided with a passage l ’, as illus
trated, extending from the lower surface thereof
directly in alinement with the de?ecting body 4.
15 The passage I’ has exhaust ports at the sides of
the electrode as illustrated.
According to this invention, the diameters of
the de?ecting surfaces are comparatively large
although the diameters should not greatly exceed
20 the openings in the hollow electrodes. Moreover,
it is necessary that the hollow electrode’ and
de?ecting body be spaced a small extent so that
complete de?ection of the entire cross section of
the gas ?ow is obtained.
25
In the case of high voltages, however, if the
de?ecting body is very close to the hollow elec
trode, provisionmust be made for preventing
reignition of the arc after extinguishing of the
same by the gas ?ow due to the fact that parts of
30 ‘the electrode structure remain at high tempera
ture for a short time. Reignition of arcing may
be prevented in accordance with this invention by
forming the hollow electrodes so that they func
The arrangement shown by Fig. 2 comprises
a de?ecting body 3 wherein the de?ecting sur
face 3' is generally of conical shape extending
away from the direction of gas ?ow. The de?ect
ing body 4 associated with the electrode 2 in
the present instance is provided with a central
bore in which a movable contact rod 5 is posi
tioned.
In the closed circuit position as shown by Fig.
2a the rod 5 is elevated so as to engage the de 10
?ecting member 3, and in the circuit opening
operation the rod 5 serves as an arcing tip. It
will also be apparent that the arrangement may
be similar to that of Fig. 1. That is, the elec
trodes I and 2 may engage and the rod 5 serve as 15
an arcing tip at the de?ecting member 4.
I
In the present instance the de?ecting member
4 may consist of metal or insulating material,
or it may be coated with an insulating material,
so that the points of the arc base are limited to 20
predetermined positions on the electrode struc
ture. The circuit opening operation is essentially
the same as that described in connection with
Fig. 1, the electrode structure of Fig. 2 being par
ticularly adapted for circuit breakers or switches 25
of the gas blast type. However, it will be ap
parent that the rod-like de?ecting member 4 of
Fig. 1 may be movable as in Fig. 2 to bridge the
electrodes l and 2.
In addition to the above described advantages, 30
in so far as arc interruption is concerned the
sharp fan-like de?ection of the gas current and
the change of cross-sectional ?ow likewise occur
tion as an electric screen or shield for the de
'
35 ?ecting surface.
ring result in damping of the sharp switching
The circuit interrupting operation is performed
noise characteristic of the gas blast switch. This
factor may be taken into consideration in' the
by directing gas under pressure from a suitable
source between the electrodes I and 2 as indicated
by the directional arrows. The gas ?ows axially
40 through the passages I ' and 2' in opposite di
rections substantially parallel to and around the
are between the electrodes l and 2, each jet be
design of the de?ecting bodies.
In the circuit interrupting method above de
scribed, it is immaterial in principle whether one
creased radially of the base of the arc. The are
with respect to the arc previous to the extinction
of the arc is chie?y taken into account. Accord
ingly, a decrease for example of the gas used for
extinguishing the arc and an increase of the
or two exhaust ports for the gas are used in the
circuit interrupter, since with the selection of 40
such a design the determining considerations
ing sharply de?ected at the de?ecting surfaces 4' concern
the most favorable ionization and re
and 3’ so as to assume a substantially fan-shape
moval of metallic vapors. In the case of the
?ow. The direction of ?ow is, therefore, abruptly present
invention the application of the gas ?ow
changed and the velocity is likewise greatly de
which is not appreciably lengthened by this
method, and therefore does not build up a great
50
counter-pressure, is e?ectively interrupted at a
subsequent current zero. In the circuit breaker
shown by way of example by Fig. 3, the electrode
structure corresponds in form and position to
that shown by Fig. 1. The ?xed electrode struc
55 ture 2-3 is disposed at one end of an insulating
housing H, and the coacting relatively movable
electrode structure i-4 is guided for vertical
reciprocal movement in the opposite end wall of
said housing. An insulating partition P is
60 mounted within the housing so as to con?ne the
?ow of gas at the electrode l as previously de
scribed.
When gas under pressure is admitted as in
dicated, such as through laterally disposed gas
supply conduits, to the intermediate part of the‘
housing H upon separation of the contacts, the
arc is interrupted in the manner previously de
scribed, the gas exhausting in opposite directions
past the electrode structures as illustrated by the
directional arrows.
Actuation of the movable
electrode structure l—4 is accomplished by means
of suitable operating mechanism (not shown).
The ?xed and movable electrode structures can
be connected respectively to the external circuit
75 terminals as diagrammatically indicated at T.
interrupting capacity and of the voltage rating
are obtained.
50
It should be understood that the invention is
not limited to speci?c 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 55
spirit of the invention.
What we claim as new and desire to secure by
Letters Patent of the United States, is:
1. In a gas blast arc-interrupting system, the
method which comprises directing gas under 60
pressure at high velocity around and longitudi
nally of the axis of the arc to be interrupted in
opposite directions toward both of the roots of
said are, and sharply de?ecting the ?ow of said
gas adjacent said roots radially from said axis.
2. An electric circuit interrupter of the ?uid
blast type comprising coacting electrode struc
ture forming a centrally disposed ?uid passage,
said electrode structure separable to form an arc 70
longitudinally of said passage, means for direct
ing a ?uid under pressure into said passage at
an intermediate point so as to ?ow longitudinally
of said are without traversing and lengthening
the same, and a de?ecting member at one end 75
3 v
2,184,506
of said passage for sharply de?ecting the ?ow of
said ?uid away from and substantially radially
01' said are.
'
3. An electric circuit interrupter of the gas
blast type comprising a pair of hollow electrodes,
arcing means between which an arc may extend
through said hollow electrodes, means interme
diate said electrodes for directing a ?ow of gas
through said electrodes in opposite directions so
10 as to flow longitudinally of said are without
lengtheningthe same, and de?ecting means asso
ciated with each of said electrodes at points
adjacent the arc roots respectively, said de?ect
ing means being positioned at the exhaust open
15 ings of said electrodes and arranged so as to
de?ect sharply the flow of said gas away from
and generally radially of said arc.
4. An electric circuit interrupter of the gas
blast type comprising coacting electrodes, one
20 electrode having a gas passage therethrough,
said electrodes separable to form an are upon
opening of the circuit within said passage, means v
for directing flow of gas under pressure laterally
of and into said passage and parallel to said are
without substantial traversing of the arc, and
a de?ecting member closely spaced with respect
to the exhaust opening of said electrode passage
and arranged so as to de?ect said ?ow at said
exhaust away from and generally radially of
said are.
>
5. An electric circuit interrupter of the gas
blast type comprising a pair of electrodes having
alined gas passages therethrough, a contact rod 10
movable through said passages for opening and
closing the circuit, means for directing ?ow of
gas under pressure from a point intermediate
said contacts through said gas passages so as
to ?ow in opposite directions substantially par 15
allel to an are formed upon the circuit opening
movement of said contact rod, and de?ecting
members associated with each of said electrodes
adjacent the exhaust openings of said passages
for de?ecting said gas away from the arc in fan
like ?ow.
HERBERT BUCHWALD.
ERWm MARX.
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