US3267242A

US3267242A - Arc splitter plate design for oil circuit breaker

Info

Publication number: US3267242A
Application number: US350268A
Authority: US
Inventors: Lorne D Mcconnell
Original assignee: ITE Circuit Breaker Co
Current assignee: ABB Inc USA; ITE Circuit Breaker Co
Priority date: 1964-03-09
Filing date: 1964-03-09
Publication date: 1966-08-16
Anticipated expiration: 1983-08-16

Description

1966 L. D. MOCONNELL, 3,267,242

ARC SPLITTER PLATE DESIGN FOR OIL CIRCUIT BREAKER File d March 9, 1964 I a 5- 3 INVENTOR. y 5/ Zak/v! .0 M caw/la! 52 zr/eazamq fiwee fisea JFFg/r United States Patent 3,267,242 ARC SPLITTER PLATE DESIGN FOR OIL CIRCUIT BREAKER Lorne D. McConnell, Sierra Madre, Califi, asslgnor to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Filed Mar. 9, 1964, Ser. No. 350,268 6 Claims. (Cl. 200-450) This invention relates to oil circuit breakers, and more specifically relates to a novel interrupter structure for an oil circuit breaker which provides improved discharge of oil and arcing products through the ports of the interrupter chamber.

Interrupter structures for oil circuit breakers are well known to the art, and may be seen, for example, in detail in copending application Serial No. 2,390, now United States Patent No. 3,128,360, filed January 14, 1960, in the name of Earl B. Rietz, entitled Single Contact Interrupter, and assigned to the assignee of the present invention.

Such interrupter structures generally comprise are splitter plates arranged within the interrupter chamber which force the venting of are products from a plurality of separate ports in the interrupter chamber housing. A great variety of splitter forms and reservoir shapes have been employed. The form and shape of the reservoir and the positioning of the are within or through such a chamber area has, in many previous interrupter chambers, allowed for the development of a circular flow pattern of arc products and oil. Such flow may result in the entrapment of ionized are products within the interrupting chamber in reservoir chambers.

The principle of the present invention is to form an arc splitter plate in such a manner that oil and contaminated products are necessarily forced away from the rear of the small chambers and out of the venting ports due to the pressure which exists during arcing conditions. Thus, the rear of the chamber is provided with a projecting section which inhibits a circular flow pattern and necessarily turns back oil through the arc column to exhaust the oil at the venting ports. This flow pattern efiectively breaks up and cools the ionized gas column effecting interruption at current zero.

Moreover, the novel construction of the splitter plates of the present invention provides a region in front of the movable contact which permits communication between the adjacent oil reservoirs whereby an axial blast may be applied to the are along with a radial blast through the venting ports, and also permits room for the formation of an axially directed arc. Moreover, the openings in the splitter plates closely confine the arc to a linear column, this column being held central to the axis of the exhaust passage and closely disopsed to the inner throat of this passage.

Accordingly, a primary object of this invention is to provide a novel construction for the splitter plates of an oil circuit breaker which permits more complete exhaust of the are products from the interrupter chamber.

Another object of this invention is to improve the venting characteristics of the interrupter structure of an oil circuit breaker.

A further object of this invention is to provide a novel arrangement for an oil circuit breaker which is simple and relatively inexpensive in construction.

These and other objects of the invention will become apparent from the following description when taken in connection with the drawing, in which:

FIGURE 1 is a cross-sectional view taken through an interrupter structure constructed in accordance with the present invention.

ice

FIGURE 2 is a top view of one of the arc splitter plates of FIGURE 1.

FIGURE 3 is a cross-sectional View of FIGURE 2 taken across the line 33 in FIGURE 2.

FIGURE 4 is a top plan view of the lowermost splitter plate of FIGURE 1.

FIGURE 5 is a cross-sectional view of FIGURE 4 taken across the line 55 in FIGURE 4.

FIGURE 6 is a top view of the upper plate of the interrupter of FIGURE 1.

Referring now to the figures, and particularly to FIG- URE 1, I have shown therein an interrupter structure which could, for example, be used as illustrated in above noted'copending application Serial No. 2,390, now United States Patent No. 3,128,360, which is incorporated herein as a part of the present invention.

More specifically, the interrupter structure of FIG- URE 1 is comprised of a container 10 which can be formed of any suitable material and has a predetermined number of venting ports such as

venting ports

11, 12 and 13 in the walls thereof. Container 10 then has a constricted portion 14 which serves to receive a throat bushing 15, as illustrated. The container 10 additionally has an interior key member 16 which serves to key the various plates to be contained by container 10, as will be described more fully hereinafter.

The upper portion of container 10 is then provided with

suitable studs

20 and 21 for connecting the compression ring 22 to a suitable adaption means or bushing which is to carry the interrupter of FIGURE 1 within an oil filled tank of a circuit breaker.

A contact block which has contact fingers 23 and extending arcing contact finger 24 extending therefrom is then suitably fixed in position with respect to ring 22 where these contact fingers are arranged circularly about the hub 25 in the usual manner, and as it shown in the copending application Serial No. 2,390, now United States Patent No. 3,128,360, noted above. As is also standard, a bayonet-type contact schematically shown by the dotted line 26 can move upwardly and into engagement with

contacts

23 and 24 and is movable out of engagement therewith and from the bottom of throat bushing 15 when contact 26 is moved to its disengaged position.

The interior of container 10 then includes the

various plates

30, 31, 32 and 33 which are supported at the bottom by throat bushing 15 and are compressed at the top by the compression ring 34 of insulation material which has a clamping ring 35 threadably received by threads 36 on the interior of chamber 10 and threaded downwardly to compress the stack of plates.

The upper plate 33 is illustrated in FIGURE 6 where it is shown that the plate has a circular opening 40 therein which has an extending portion 41 for receiving the extending arcing contact finger 24. Plate 33 also has a notch 42 therein which is keyed into keying member 16 to insure appropriate angular alignment of plate 33.

Each of

plates

31 and 32 are then constructed in the manner shown in FIGURES 2 and 3 for plate 32. The plate 32, as well as the other various plates of FIGURE 1, may be formed of a suitable vulcanized fibre sheet, or any other suitable material, and has a keying notch 50 therein which cooperates with key 16 to insure proper alignment within chamber 10.

In accordance with the invention, the rear of the plate 32 is provided with an extending tip portion 51 which provides two

flow chambers

52 and 53 atop the lower platform surface 54. Each of

chambers

52 and 53 then join adjacent port 11 for the case of plate 32, and port 12 for the case of plate 31, as shown in FIGURE 1.

An opening 55 which is elongated at the port region 56 is then provided in the lower platform 54 to provide for passage of the movable contact 26 of FIGURE 1 with room being left at region 56 for the passage of an arc and arcing products during interrupting conditions.

The lowermost plate 30 (FIGURES 2, 4 and 5) which has the keying notch 60 therein for reception "by key 16 of FIGURE 1 is formed in an almost identical manner to that of plate 32 where similar numerals have been given to elements of the plate. Thus, plate 30 has the two

separate chambers

52 and 53 which are isolated by projection 51 and join in a channel 61 which is adjacent the lower port 13. The opening through plate 30 is a circular opening 62 which is sufficiently large to receive contact 26. It will be noted that the channel 61 of plate 30 is somewhat smaller than the outlet channel of

plates

31 and 32. Moreover, there is a relatively close fit between the contacts 26 and opening 62 of plate 30. During interrupting conditions, this will insure sufficient pressure to cause venting operation at

leastin vents

11, 12 and 13 to be built up within chamber until the contact rod 26 leaves :the throat bushing 15.

During arcing conditions, and in accordance with the invention, there is substantial pressure of oil and are products which exist in the

chambers

52 and 53 defined by each of

plates

30, 31 and 32. The projection 51 is positioned to inhibit the development of a circular flow pattern. However, forces on the are or random motion of the arc column within the chamber might be such as to initiate a circular flow within the chamber. The positioning and shape of the projection 51 will result in a flow pattern, shown by

arrows

70 and 71 in FIGURE 2, that will force oil from the rear of the reservoir to be projected forward toward the

exhaust openings

11, 12 and 13 and across the arc column within the confines of the openings through plates 55. This flow pattern effectively breaks up and cools the ionized gas column effecting interruption at a current zero.

Although this invention has been described with respect to preferred embodiments thereof, it should be understood that many variations and modifications will now be obvious to those skilled in the art, and it is preferred therefore that the scope of the invention be limited not by the specific disclosure herein, but only by the appended claims.

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows:

1. An arc splitter plate for the interrupter structure of an oil circuit breaker; said plate having a platform section and a rim section extending from said platform section; said platform section having a contact receiving opening therethrough; said rim section having an outlet opening therein, and a single inwardly projecting rib section on the side of said platform directly opposite said outlet opening; said rib defining two paths 'of flow for oil atop said platform from the said rib toward said opening and bounded by the inner walls of said rim.

2. The splitter plate of claim 1 wherein said contactreceiving opening has a generally circular shape with an elongated section extending toward said outlet opening.

3. An interrupter structure for an oil circuit breaker; said interrupter structure including a tubular interrupter housing having axially displaced ports therein, and a stack of a plurality of parallel arc splitter plates contained within said tubular housing and extending perpendicularly to said housing; each of said are splitter plates having a platform section and a rim section exending from said platform section; said platform section having a contact receiving opening 'therethrough; said rim section having an outlet opening therein, and a single inwardly projecting rib section on the side of said platform directly opposite said outlet opening; said ri'b defining two paths of fio-w for oil atop said platform from the said rib toward said opening and bounded by the inner walls of said rim; said outlet opening of each of said arc splitter plates being adjacent a respective port of said plurality of ports.

4. The interrupter structure of claim 3 wherein the last of said stack of arc splitter plates has a smaller outlet opening than the outlet openings of the other of said are splitter plates.

5. The interrupter structure of claim 3 wherein the last of said stack of arc splitter plates has a circular contact receiving opening in its said platform and the remaining plates of said are splitter plates have generally circular contact receiving openings with elongated sections extending toward their said outlet openings; each of said openings being axially aligned with one another.

'6. The interrupter structure of claim 5 wherein the last of said stack of arc splitter plates has a smaller outlet opening than the outlet openings of the other of said are splitter plates.

References Cited by the Examiner UNITED STATES PATENTS 1,955,216 4/1934 Whitney et al. 200 3,128,360 4/1964 Rietz 200-150 FOREIGN PATENTS 870,998 6/ 1961 Great Britain. 927,548 5/ 1963 Great Britain.

ROBERT K. SCHAEFER, Primary Examiner.

ROBERT S. MACON, Examiner.

Claims

1. AN ARC SPLITTER PLATE FOR THE INTERRUPTER STRUCTURE OF AN OIL CIRCUIT BREAKER; SAID PLATE HAVING A PLATFORM SECTION AND A RIM SECTION EXTENDING FROM SAID PLATFORM SECTION; SAID PLATFORM SECTION HAVING A CONTACT RECEIVING OPENING THERETHROUGH; SAID RIM SECTION HAVING AN OUTLET OPENING THEREIN, AND A SINGLE INWARDLY PROJECTING RIB SECTION ON THE SIDE OF SAID PLATFORM DIRECTLY OPPOSITE SAID OUTLET OPENING; SAID RIB DEFINING TWO PATHS OF FLOW FOR OIL ATOP SAID PLATFORM FROM THE SAID RIB TOWARD SAID OPENING AND BOUNDED BY THE INNER WALLS OF SAID RIM.