Document X7owbpqnObMjpbOkNj0Lnvzod
Patented Apr. 24, 1934
1,955,961
UNITED STATES PATENT OFFICE
1,955,961 ABC SUPPKESSOE WITH SMGOTTaC
FBATtlSiS John Q. Jackson, Detroit, Mick., assignor to
> Square Company, Detroit, Mich., a corpora tion of Michigan Ajwfiegiteii July 6 1931, Serial No". 549,061
6 Claims. (Cl. 200--149}
The invention relates to electric switches or cir of the blade. As .shown in Figure 4 the contact
cuit breakers and more particularly to knife is substantially U-shaped having laterally spaced
switches.
'
legs 15 return bent toward each other as at 16 to
The primary object of the invention is to pro- form contact pairs 17 for clamping the switch
8 vide an improved construction for suppressing blade therebetween. The yoke B is so disposed 60
the arc formed upon the breaking of the circuit. that when an arc is drawn in the mid-portion of
Another object of the invention is to produce a the area D enclosed by the barrier plates, this
magnetic suppressing action without the use of arc wilt almost immediately by the continued
coils or other auxiliary devices connected into the opening of the blade of the switch be caused to
10 main circuit.
pass through or interlace the magnetic yoke B 65
A further object is to obtain rapid suppression thereby constituting the fractional turn about
of the arc by the combined action of closely such yoke and causing the magnetic yoke to be
spaced insulated barrier plates and a magnetic self-excited by its relationship to the path of the
device designed to retain the arc between ,the current or of the arc.
15 plates and diffuse the same to effect quick sup I find when this is done .that the tendency of 70
pression thereof.
the magnetic field so excited is to lengthen the
These and other objects are attained by provid path of the current in the yoke by blowing the
ing the novel features of construction hereinafter arc away from the contacts which have broken
more fully described and illustrated in the accom- circuit. As distinguished from blowing the arc
20 panying drawings, wherein
towards such contacts this has two effects: first, 75
Figure 1 Is a side elevation of a switch;
to prevent the arc from leaving the area enclosed
Figure 2 is a transverse section on the line by the arc suppressor plates A unless it so leaves
2--2 of Figure 1: .
by the most distant or remote opening; and sec
Figure 3 is a sectional elevation on the line ond to increase the length of the arc in a shorter
25 3--3 of Figure 2;
..
period of time than could be accomplished by the 80
Figure 4 is a cross section on the line 4--4 of actual mechanical movement of the moving knife
Figure 2;
blade 10 which is in itself limited in speed by
Figure 5 is a sectional elevation through a modi inertia and friction and impelling means.
fied construction of switch;
According to my Invention where the barriers
30 Figure 8 is a sectional plan view thereof on the are closely spaced on either side of the arcing 85
line 6--6 of Figure'5;
gone, they provide surfaces upon which the metal
Figure 7 is a cross section on the line 7--7 of lic conducting vapors of the arc are deposited
Figure 5.
out and rendered relatively non-conducting,
Tills dcvwe comprises the ms o closely -spaced thereby greatly reducing the conductivity of the
55 suppressor or fc&rr.'ar plates- a oX insulaling ma vapor within the zone of the arc. This is espe- 99
teriel with the added fcarorc of a magnetic yoke daily true where the arc Is formed between cop
or blow-out 3 so arranged as to include interlac per contacts. My invention differs radically from
ing the magnetic circuit with some part of the the method of lessening the conductivity of an
electrical circuit. - The trade term "blow out" is arc by de-ionizlsg the air or gas within its area.
40 applied to the magnet B but it is to be understood By reason of my combination of the closely spaced 95
that the arc is actually blown or directed in such suppressors with the magnetic feature, the arc
a way that it is-normally ruptured while retained is not only prevented from receding from the zone
between the plates rather than blown out of the of the suppressors but is actually impelled to pass
space therebetween. In the preferred form as through such zone in an elongated path. As
45 shown in Figure 1 the magnetic yoke B is in .a evidencing the useful effect of the barrier plates loo
substantially u-form, the yoke passing on-the A, I find that a definite color, which in the case of
outside of the suppressor plates and enclosing copper contacts is red, is set up upon the face of
same, insulation being provided on the back part the barrier {dates. This coloration is produced
by means of an added Insulating part C so that by the condensation of materials from the arc,
50 no bare parts are exposed to contact with live which materials while in the are had contributed ios
current-carrying parts or with the arc. The knife to its conductivity and had therefore served to
blade 10 is hlngedly supported by the bracket 11 prolong the duration of such arc both in respect
on the base 12 and the free end 13 of the blade to time and space occupied. However, it has
passes between the barrier plates A. 14 is a.blfur- been proven by tests that, whereas this material
55 sated spring contact for engaging the free end when in the arc contributed to the conductivity, no
2 1.085.661
the deposition of the same material upon the to strike against the fiat face 25 of the fixed con
barrier surfaces is non-conducting to such a tact.
-
degree as to answer all tests which would be ap The baffle plates A are closely spaced as in the
plied to an insulator. For instance, not only the preceding structure, there being merely sufficient
6 deposit formed after a single flash of the arc but mechanical clearance between the baffles and the 80
1 accumulated deposits formed by 6000 such flashes sides of the contactor 22. To accommodate the
in succession superimposed upon each other will enlarged width of the fixed contact the lower por
withstand an alternating current electrical volt tion of the baffle is formed by the insulating aide
age between points one-half inch apart upon the plates 31 are arranged outside of the fixed contact
10 surface of such material of 5000 volts to 7000' in order to enclose the same. Thus, while the 85
volts before flashing, whereas such flashing would. space surrounding the fixed contact is of enlarged
occur between similar points suspended in air at width, the space between the active portions of the
approximately 8000 volts.
, baffles is maintained small in order to have the
Wb..Ie my mvenfi-it: in i*k broader
easy full effect of the magnetic blow out feature.
IS .if -monUiF ; it! evu-nrucijuris utilizing barrier It.is to be noted that in the usual types of con- 90
Kiiiics -u any insulating material, i have l-'Und factor switches,' a flat face of enlarged width is
'h.-tf main rvn.vs of 'r..1i!' ire ift'r superiur caused to move into engagement with the fixed
t_> ether- -tr..i I xv. -. ,tiv> found tisat thete ,j a contact, whereas in my improved design the con-'
marfet-d aiiferiT.r" tsetwevn -'fj-sani materials that factor is moved edgewise, thereby permitting the
20 are -.null ,'r`iy c^s;:,.dvr.d ajuuilv insulating and close spacing of, the baffle plates between which it 95
i-vdaiiv reUiiaitt.
operates. . '
,,
,
Th n, mV t*r.'i>rred Eutetiuls are compes.uons The contactor 20 is, as shown, carried by an
Kiv.-.'t'.1- -<;J to ordinary canun-'rciai densities and insulating support 32 which in turn Is hinged at cor.tati-.ixif .i.-ccsios toe :4her wrh Portland re- 33 on an insulating base 34. The inner end 23 of
25 nteni;. nsa-ifit-idfe < t-fn.yii. vir i.me of ungi&zbd p-x- the blade is pivotally connected to the support by 100 : ni.sin Of lesser value for use in my improved a pin 35 engaging a socket 36. 37 is a spring
- construction are. fibre,- bakelite, impregnated ma bearing bn the top surface of the portion 23 for
terials and compositions of asbestos and. China- maintaining the contactor in resilient engage
wood oil or other oils adapted to harden and set. ment with the fixed contact. A flexible lead 38
' 30 These last materials where use in my combina extends between the inner end 23 of the contactor 105
tion do not result In as effective a deposition or and a terminal 39 on the Insulating base. The
. condensation from the arc. Thus in practicing contactor may be operated in any suitable man
my invention care should be taken to select in ner, either manually or magnetically In the man
sulating materials which when used for the close- ner well understood in the art.
35 ly spaced barrier plates in conjunction with the The magnetic yoke B is arranged in the same no
magnetic arrangement will cause condensation of manner as shown in the construction first'de
particles from the arc. The preferred materials scribed and it is either arranged to overlie the
above mentioned are the best for this purpose baffle plates or to be molded thereinto.
but it- is to be understood that the invention is What I claim as my invention is:
40 not limited to the specific materials.
1. A" switch comprising a pair of insulating ns
It is also to be noted that the air gap portion plates, a stationary contact, a second contact
of the magnetic circuit shall be at the zone of the movable between said plates into engagement with
, arc, and the closed portion C, if any portion be said stationary contact, said plates being spaced
' closed, is remote from such relation to the circuit apart a distance slightly greater than the thick
45 and is in the general direction toward which it is ness of the movable contact, and a U-shaped mag- 12Q
desired to impel the arc. The pole pieces E of the net embracing the space between said plates, said
magnetic ybke are so located as to include a por magnet having poles of relatively small cross
tion of the circuit containing the arc and to con sectional area adjacent an edge of each of-said
centrate the magnetic field at the arc zone, there- plates and a closed end adjacent an opposite edge
GD fore not only exciting the magnet by such rela of each plate, said stationary contact being so 125
tion but rendering it certain that the arc will be disposed with respect to said magnet that the
retained within the area,of such device or ex arc formed between the contacts is diffused by
' ' pelled in the most useful direction.
said poles in the direction of saiddosed end.
In the modified construction illustrated in Fig- 2. A switch comprising a pair of insulating
55 urea 5, 6 and 7 the invention is shown as applied plates, a stationary contact, a second contact |3q
to a contactor type of switch. However, in order movable between said plates into engagement with
to preserve the important feature of my invention said stationary contact, said plates being spaced
which involves the maintenance of the barrier apart a distance slightly greater than the thick
60
plates closely adjacent, ! have modified the arrangement of the contactor arms so that they move edgewise through the space between the barrier plates and utilize the edge of the blade for striking the fixed contact. Thus, as shown
.
ness of the movable contact, and a U-shaped mag net embracing the space between said plates, said magnet having poles of relatively small cross sectional area adjacent an edge of each of said
plates and a closed end adjacent an opposite edge of each plate, the width, of said magnet being
135
in the drawings, the contactor blade 20 is formed substantially less than the width of said plates, 140
with a twisted portion 31 so that the outer end said stationary contact being so disposed with
22 of the blade lies in a plane transverse to the respect to said poles that the arc formed between
plane of the inner or supporting end 23. The the contacts Is diffused in the direction of said
. fixed contact 24 has the contacting surface 25 (dosed end and thereby retained between said
>f 3 ' bf greater width than the edge of the contactor plates.
14
with which it engages. As shown, the fixed con 3. A switch comprising a base, a pair of insulat
tact has the downwardly extending flange 25 se ing plates mounted on said base, a stationary con
cured to the upwardly extending flange 27 of the tact, a knife blade pivoted on said base and mov
conducting bar 28 by a bolt 29. Thus it will be able between said plates into engagement with
y=; seen that the edge of the contactor is arranged said contact, said plates being spaced apart a dis- 1
1,985,061
3
tance slightly greater than the thickness of the plates, a stationary contact, a second contact
blade, and a U-shaped magnet embracing the movable between said plates Into engagement
space between said plates, said magnet having a .with said stationary contact, said plates being
closed end, and pole pieces of relatively small spaced apart a distance slightly greater than the .
5 cross-sectional area formed at the ends of said thickness of the movable contact, and a U -shaped 39
magnet, said pole pieces and said closed end being magnet embracing the space between said plates,
adjacent opposite edges of said plates, said pole said magnet haying poles of relatively small
pieces being disposed between the pivot of said cross-sectional area and a closed end, said sta
, blade and said Closed end, and said contact being tionary contact being so disposed with respect to
10 disposed between said closed end and said pole said magnet that the arc formed between the gg
pieces. '
contacts is diffused by said poles in the direction
4. A switch comprising a pair of Insulating of said closed end and retained between said
plates, a stationary contact, a second contact plates.
,
'
movable between said plates Into' engagement S. A switch comprising a pair of insulating
15 with said stationary contact, said plates being plates, a stationary contact intermediate opposite -q
spaced apart a distance slightly greater than the edges of said plates, a second contact movable w
thickness of the movable contact, and a U-shaped between said plates into engagement with said
magnet embracing the space between said plates stationary contact, said plates being spaced apart
and having a width substantially less than the a distance slightly greater than the thickness of
. go width of said plates, said magnet being disposed the movable contact; and a U-shaped magnet
in a plane substantially at right angles to the embracing the space between said plates, said
line of the arc formed between said contacts and magnet having poles of .relatively small cross
substantially centrally of said plates, the magnet sectional area and a closed end, said stationary
having poles of small cross-sectional area' at its contact being so disposed with respect to said
25 ends adjacent an edge of each plate and a closed magnet that the arc formed between the contacts loa
end adjacent an opposite edge of each plate, said 'is diffused by said poles in the direction of said
stationary contact being contiguous to a portion closed end.
,
of said magnet.
JOHN G. JACKSON.
5. A switch comprising a pair of insulating
30
35 110 40 115 45 120 50 129 55 120 60 139 65 199 70 149 75 110
April 24, 1934.
J. G. JACKSON ARC supprsssqe with hachetic feature
1,955,961
Filed July 6, 1931
g Sheeis-SHeet 1
INVENTOR
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ATTORNEY-^