U.S. patent number 3,900,946 [Application Number 05/409,650] was granted by the patent office on 1975-08-26 for method for making arc extinguishing chamber.
This patent grant is currently assigned to McGraw-Edison Company. Invention is credited to Melbourne G. Jawelak.
United States Patent |
3,900,946 |
Jawelak |
August 26, 1975 |
Method for making arc extinguishing chamber
Abstract
An arc extinguishing chamber for oil filled type circuit
interrupter is formed of a fabricated or molded block of suitable
insulating material. Intersecting holes are drilled or molded to
provide passageways for the contacts, oil entrance and arced
products exhaust.
Inventors: |
Jawelak; Melbourne G.
(McMurray, PA) |
Assignee: |
McGraw-Edison Company (Elgin,
IL)
|
Family
ID: |
23621413 |
Appl.
No.: |
05/409,650 |
Filed: |
October 25, 1973 |
Current U.S.
Class: |
29/592.1; 218/91;
218/96; 218/106; 218/103; 29/428 |
Current CPC
Class: |
H01H
33/75 (20130101); Y10T 29/49826 (20150115); Y10T
29/49002 (20150115) |
Current International
Class: |
H01H
33/75 (20060101); H01H 33/70 (20060101); H01H
033/68 () |
Field of
Search: |
;29/592,622,624,627,631,467,469,527.1,527.3,557,558,428 ;200/150
;264/237,271,272,275,277,278,299,328 ;83/13,29,39 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Herbst; Richard J.
Assistant Examiner: Walkowski; Joseph A.
Attorney, Agent or Firm: Gealow; Jon Carl
Claims
I claim:
1. A method for making an arc extinguishing chamber for a bulk oil
circuit breaker wherein a stack of blocks are first secured in a
unitary assembly to form a solid block, and thereafter a through
hole for receiving the circuit breaker contacts, holes intersecting
said through hole to provide passages for entrance of oil into said
through hole, and holes intersecting said through hole for
exhausting arced products from said through hole are drilled in
said solid block.
Description
BACKGROUND OF THE INVENTION
Arc extinguishing chambers for circuit interrupters of the liquid
dielectric filled type have been constructed in the past by
stacking a plurality of non-conducting fibrous plates. These plates
were of varying, and sometime, alternating or repetitive shapes so
as to form the desired arc chamber and passageways. The plates were
secured to each other and with respect to the overall circuit
breaker assembly by pins or rods passing through holes in each of
the plates. Or in the alternative, the plates might be indexed with
respect to each other by forming embossed areas on each of the
plates. Such an arrangement for indexing the plates is disclosed in
U.S. Pat. No. 3,080,467 assigned to the assignee of the instant
application. Thus, in the prior art method of assembling an arc
extinguishing chamber utilizing a plurality of specially formed
plates, which due to variations in their form had to be stacked in
a particular order, assembly required considerable labor and
considerable care to assure proper stacking.
It is accordingly an object of this invention to provide an arc
extinguishing chamber for a circuit interrupter of the liquid
dielectric filled type which is easier to assemble and construct
and provides the desired operating performance.
SUMMARY OF THE INVENTION
The object of this invention in one form thereof is accomplished by
fabricating or molding a block of suitable insulating material with
suitable holes molded or drilled therein to provide a through
passage for the contacts, and passages intersecting the through
passage for oil insertion, and for arced product exhaust. With the
arc extinguishing chamber formed as an integral assembly, it is
readily incorporated in the circuit interrupter.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of an arc extinguishing chamber made
in accordance with a preferred method of this invention;
FIG. 2 is a top plan view of the arc extinguishing chamber shown in
FIG. 1;
FIG. 3 is an elevation view of the arc extinguishing chamber in
transverse section taken along the line 3--3 in FIG. 2.
FIG. 4 is an elevation view of the arc extinguishing chamber in
transverse section taken along the line 4--4 in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, there is shown in FIG. 1 a
perspective view of an arc extinguishing chamber made in accordance
with one of the preferred methods of this invention. As shown in
FIG. 1 the chamber 2 is fabricated by assembly of insulating blocks
4, 6, 8, 10, 12 and 14. Blocks 4, 6, 8, 10 and 12 are shown to be
of the same shape, having opposed acruate sides 16, 18, 20, 22 and
24 which are shown and the opposite sides not shown in FIG. 1. The
arcuate sides are connected by planar sides 26, 28, 30, 32 and 34
shown and opposing planar sides not shown. The uppermost insulating
block 14 is shown to have a cylindrical shape, the radius and
diameter of which is the same as that of the opposed arcuate
surfaces of the remaining blocks. Referring to FIGS. 1 and 2 the
opposed planar sides are in fact chords of the cylindrical shape of
block 14.
As shown in all of the Figures, the blocks 4, 6, 8, 10, 12 and 14
are secured to each other by pins 36, 38, 40 and 42 passing through
and secured in holes formed in alignment in the blocks. The pins as
are the blocks, are formed of a suitable insulating material such
as a fiber as is well known is the art. The blocks 4, 6, 8, 10, 12
and 14 may in addition to the pins, or as an alternative thereto,
be secured to each other by a suitable adhesive placed between
their adjoining surfaces.
After assembly of the blocks 4, 6, 8, 10, 12 and 14 into a solid or
unitory block 2, the block is suitable secured or supported so as
to drill through hole 44 which receives in spaced relationship the
contacts of the circuit breaker. Similarly, the block 2 is
supported in a jig or otherwise to drill the oil entrance holes 46,
48, 50, 52, 54, 56, 58, 60, 62 and 64. As is best seen in FIGS. 2
and 3, oil entrance holes 46, 48, 50, 52 and 54 are coaxial with
oil entrance holes 56, 58, 60, 62 and 64 respectively, such that
they may be drilled as continuations of each other, with the drill
passing through the contact thorugh hole 44. In this manner oil
entrance holes 46 and 56 may for instance be drilled by the same
drill.
As in the case of the oil entrance holes, arced product exhaust
holes 66, 68, 70, 72 and 74 are drilled in the block 2. Referring
to FIG. 2, the arced product exhaust holes 66, 68, 70, 72 and 74
may be drilled completely through the block to form an opposite set
of arced product exhaust holes as represented by the dashed lines
76.
Referring to FIGS. 1-3, notches 78 and 80 are provided for insuring
proper alignment and support of the arc extinguishing chamber 2 in
the circuit breaker. The arc chamber as utilized in a circuit
breaker is mount in a cylindrical tube formed of insulating
material. The tube has an inner diameter just slightly larger than
the diameter of the arcuate sides 16, 18, 20, 22 and 24, and is
provided with apertures in alignment with the arced product exhaust
holes. A chamber is formed by the inner surface of the tube and the
planar surfaces 26, 28, 30, 32 and 34 to provide an oil reservoir
serving the oil entrance holes.
In another embodiment of this invention, the arc chamber 2 is
formed as shown in the figures, except that instead of being
assembly of multiple blocks and thereafter drilled, it is molded as
a complete assembly. The molding die for the entire block is
provided with inserts so as to form the through hole 44, the oil
entrance holes 46-64 and the arced product exhaust holes in a
single molding operation.
It should be apparent to those skilled in the art, that while what
has been described are considered at the present to be the
preferred embodiments of this invention, in accordance with the
Patent Statutes, changes may be made in the disclosed method of
making an arc extinguishing chamber without actually departing from
the true spiral and scope of this invention.
* * * * *