US3325617A - Controlled positioning of arc runners in magnetic field - Google Patents

Description

June 13, 1967 w. A. CARTER 3,325,617

CONTROLLED POSITIONING OF ARC HUNNERS IN MAGNETIC FIELD Filed April 25, 1965 4 Sheets-Sheet l JIE-l IN VEN TOR W/l 4 4 4 i727? June 13, 1967 w. A. CARTER 3,325,617

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United States Patent 3,325,617 CGNTROLLED POSITIONHNG 0F ARC RUNNERS IN MAGNETIC FIELD William A. Carter, Devon, Pa, assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Filed Apr. 23, 1965, Ser. No. 450,451 9 Claims. (Cl. 200-147) This application is a continuation-in-part of application Ser. No. 87,440, filed Feb. 6, 1961 in the name of William A. Carter and assigned to the assignee of the instant invention, and now abandoned.

This invention relates primarily to circuit breakers and more particularly to the controlled positioning of the arc runners of such circuit breaker within the magnetic field generated within the arc chute of such circuit breakers.

Circuit breakers generally in use in present day switchgear systems are designed to include interrupting means which provide rapid extinguishment of electric arcs formed during the tripping operation. The interrupting means of the prior art are designed to include magnetic blow-out means for urging electric arcs upward into the interrupting means. Such magnetic means include a blow-out coil which is wound about an iron core. The iron core surrounds the perimeter of the interrupting means and acts to direct the magnetic field generated by the blow-out coil such that the direction of the magnetic field is transverse to the upwardly moving arc and the vertical faces of the interrupting means. Such apparatus is shown, for example, in FIGURE 6 of United States Patent No. 3,070,681, entitled, Face Wound Blow-Out Coil, issued Dec. 25, 1962, to J. D. Wood and assigned to the assignee of the instant invention.

The arc which is formed during the tripping operation of the circuit breaker is initially drawn between the breaker separating contacts. The arc then transfers to a pair of spaced parallel arc runners which are positioned in the interrupting means. In travelling upward along the spaced parallel arc runners, the arc is confronted by a plurality of spaced parallel arc plates which provide a toruous path for the arc resulting in subsequent cooling and extinguishment thereof.

Prior art circuit breakers of the type described above suffer from a serious disadvantage which the instant invention effectively eliminates. Specifically, and as will be described in further detail, the arc runners of prior art circuit breakers are positioned within the arc chute at locations which are subjected to high magnitudes of magnetic flux, and consequently the ends of a drawn are which are traveling up their respective arc runners are subjected to extremely high forces which greatly accelerate their travel up the respective arc runners. The ends of the arc arrive at the top of their runners prior to the extinguishment of the arc itself and are forced to linger there for a large percentage of the total extinguishment time. During this period the burning arc ends are concentrated at one point, the result of which is the liberation of substantial amounts of gaseous are products which can destroy adjacent insulated elements.

The instant invention contemplates an arrangement whereby the above-described prior art problem may be eliminated. Specifically, the instant invention contemplates placing the arc runners in a predetermined position relative to the blow out coil which substantially alters the magnetic flux density affecting the runner surfaces, thereby varying the magnetic flux affecting the ends of a drawn arc. Thus the ends of the arc may not be prematurely accelerated upward along their respective arc runners, and therefore the delay between the arrival of the ends of the are at the tops of their runners and the final extinguishment of the arc itself is eliminated. With car such time delay eliminated, the tops of the are are not subjected to the concentrated burning of the ends of the arc and therefore the problem described above is eliminated.

Accordingly, it is an object of this invention to provide a novel magnetic air circuit breaker including a face wound blow-out in which the arc runners thereof are positioned in a predetermined relationship with respect to the blow-out coil to vary the magnetic flux which affects the surfaces of such arc runners.

Another object of the instant invention is to provide a novel magnetic air circuit breaker including a face wound blow-out coil in which the arc runners thereof are positioned in a predetermined relationship with respect to the tblow-out coil in order to retard the movement of the ends of a drawn arc upwardly along their respective arc runners.

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

FIGURE 1 is a perspective view of a circuit breaker in which the instant invention may find application;

FIGURE 2 is a side plan view of the circuit breaker shown in FIGURE 1;

FIGURE 3 is a top plan view of the circuit breaker shown in FIGURE 1;

FIGURE 4 is a top plan view of a circuit breaker of the prior art and illustrating the positioning of the are runners of such circuit breaker with respect to the blow-out coil of such circuit breaker;

FIGURE 4a is a top plan view of a circuit breaker similar to the circuit breaker illustrated in FIGURE 4, but showing the controlled positioning of the arc runners of such circuit breaker with respect to the blow-out coil of such circuit breaker, such controlled positioning of the arc runners representing the contribution of the instant invention over the prior art;

FIGURE 4b is a top plan view of a circuit breaker similar to the circuit breaker shown in FIGURE 1, but illustrating the controlled positioning of the arc runners of such circuit breaker with respect to the blow-out coil of such circuit breaker, such breaker having no iron core;

FIGURES 5, 5a and 6 are top plan views of circuit breakers within iron cores having alternative configurations; and

FIGURE 7 is a graph showing the magnetic flux distribution obtained by the circuit breaker shown in FIG- URES 4, 4a, 5, 5a and 6.

Referring now to the drawings, FIGURE 1 shows a circuit breaker 10 which comprises upper and lower terminals 11 and 12, respectively, which are connected to the circuit to be protected.

Although FIGURE 1 shows a circuit breaker for protecting a three-phase system, this showing is merely exemplary since my invention will function equally as well with either a lesser or greater number of phases. Terminals 11 and 12 are supported and isolated from one another by support means 13. Each lower terminal 12 is connected at its opposite end to movable bridge 14 (only a portion of which is shown in FIGURE 1). The opposite end of the movable bridge 14 has a main and arcing contact secured thereto which contacts engage the main and arcing contacts, respectively, mounted to upper terminals 11 (see FIGURE 2).

Interrupting means 15 is operatively positioned with respect to the cooperating contacts of circuit breaker 10 and consists of an arc chute 16 which is pivotally supported to support 13 by pivot means 17. Iron structure 18 which consists of a plurality of U-shaped laminations 19 and 2% (see FIGURE 3) surround the mid portion of arc chute 16 and are rigidly secured thereto by fastening means 21. Magnetic core 18 has a gap 22 which separates U-shaped laminations 19 and 20. As shown in FIGURE 3, a like gap exists on the opposite face of arc chute 16. The operating mechanism (not shown) is mounted in the lower portion 23 of the carriage 24 upon which circuit breaker is mounted. Movable bridge 14 is connected to the operating mechanism used in lower portion 23 by means of push rod 25.

FIGURE 2 shows the interior of circuit breaker 10 which consists of a movable bridge 14 which is pivotally mounted to lower terminal 12 by pivot means 26. Arcing contacts 27 and main contacts 28 are fixedly secured to the opposite end of movable bridge 14 and are positioned to engage arcing and main contacts 29 and 30, respectively, which are electrically connected to upper terminal 11.

Rear arc runner 32, which has an inwardly sloping lower portion 32a is secured to are chute 16 in any well known manner. Front are runner 33 is positioned in the right hand side of arc chute 16 (with respect to FIGURE 2) and has an inwardly sloping portion 34. Conductive strips 35 and 36 serve as the path which links front are runner 33 to lower terminal 12.

Jump gap 31 is secured to arc chute 16 by pin means 31a which also secures the lower end of rear arc runner 32. Positioned between arc runners 32 and 33 are a plurality of arc plates 37 arranged in spaced parallel fashion. Arc plates 37 are supported by a ledge means 38 which are an integral part of the opposite faces of the interior of arc chute 16. It should be noted that arc plates 37 and are runners 32 and 33 may be supported and mounted by any well known means, such as the means shown for example in United States Patent ,93 entitled High Voltage Circuit Breakers, issued Sept. 4, 1952, to I. D. Wood, and assigned to the same assignee as the instant invention, or in United States Patent 2,941,060 entitled, Arc Extinguishing Means for High Voltage Circuit Breaker, issued June 14, 1960, to A. S. Caswell, and assigned to the same assignee as the instant invention. Since the arc plate and are runner mountings play no part in the novelty of the instant invention, it should be understood that the above references are cited as merely exemplary.

Mounted immediately above are plates 37 in arc chute 16 are a plurality of alternately disposed deflecting plates 39 which are positioned and secured by vertical positioning means 40. The alternate deflecting means 39 serve to prevent the commingling and gathering of heated and ionized gases in the area immediately above the top of arc chute 16 so as to prevent a flash-over from occurring between arc runners 32 and 33 immediately above arc plates 37. The structure and operation of deflecting plates 39 is more fully explained in United States copending application Ser. No. 779,419, entitled, Alternate Lateral Deflecting Means for Arc Products, filed Dec. 10, 1958, by William A. Carter, and now abandoned, and assigned to the same assignee as the instant invention.

My novel magnetic circuit, however, may be also utilized in arc chutes not containing deflection plates 39 since they play no part in the novelty of the instant invention.

Blow-out coils 41 (see FIGURES 2 and 3) are positioned along opposite vertical front faces 16a of arc chute 16. Coils 41 are wound in a configuration to encompass contacts 27-30 so that these elements are under the influence of a strong magnetic field set up by the blow-out coils 41.

As can be seen in FIGURE 3, the laminations of iron core 18 define planes which are parallel to the plane of the paper upon which FIGURE 3 is drawn, which planes are transverse to the plane of the blow-out coils 41 (extending along the vertical front faces 16a of the arc chute 16). Thus, as can be most clearly seen in FIGURE 3, the plane of the entire core structure may be thought of as a plane which is transverse to the plane of the blow-out coils 41. Although FIGURE 3 shows the use of an iron core to intensify the magnetic flux within the arc chute,

tribution using the prior art magnetic cores 42 shown in FIGURES 4 and 4a. Curve 104 shows the magnetic flux distribution in a circuit breaker having no iron core. It should be noted that these curves are substantially flat along their length and thus may be said to represent a uniform magnetic flux within the area between the arc runners.

FIGURE 4 shows the positioning of the rear and front are runners 320 and 330, respectively, with respect to the blow-out coils 41 for the prior art configuration. Such positioning corresponds to the positioning of arc runners 60 and 62 of the aforementioned Wood Patent 3,070,681, within the area defined by blow-out coil 70. From FIG- URE 7 it can be seen that such positioning results in the surfaces of arc runners 320 and 330 being under the influence of the greatest magnitude of magnetic flux for curve 101). Note that the magnetic flux shown graphically in FIGURE 7 by the flat portion of curve is approximately 2000 gauss, and that such magnitude of magnetic flux is influential on the surfaces of arc runners 320 and 330.

Thus the ends of an are which is drawn between arc runners 320 and 330 will be accelerated at a high rate of speed and prematurely arrive at the tops of these arc runners prior to the extinguishment of the are which is being slowed down within the central portion of the arc chute 16 by the interposed arc plates 37. The end result is that the ends of the are are concentrated at the tops of the arc runners for a time delay which corresponds to the movement of the center portion of the arc upwardly into the arc chute to a point at which it can be extinguished. This time delay results in excessive deterioration of the tops of the arc runners and reduces the effective life of the circuit interrupter, as previously discussed.

As can be seen in FIGURES 4a and 4b the instant invention contemplates that the arc runners 32 and 33 may be selectively located to utilize the field that is required by the particular interrupter. That is, when it is desirable to diminish the velocity of one end of an arc, the associated arc runner may be placed in a low value of magnetic flux. Such embodiment is shown in FIGURES 4a and 4b wherein arc runner 33 is positioned in a low magnetic field.

FIGURE 7 shows the above described controlled positioning of arc runner 33 wherein arc runner 33 is influenced by low values of magnetic flux. Note that the end of curve 100 dips sharply in the region immediately adjacent the surfaces of arc runner 33. The affect of this controlled positioning is to reduce the force on the end of a drawn arc and thus diminish its velocity up are runner 33, thus preventing premature arrival of the end of the arc prior to the extinguishment of the arc itself.

On the other hand, if it is desirable to accelerate one end of a drawn arc, the runner can be positioned in a more intense magnetic field. Such embodiment is shown in FIGURE 4b wherein arc runner 32 is deliberately moved toward the center of the arc chute. Such movement is preferably limited to positions within the range indicated at 308 in FIGURE 7. It is clear that one would not place arc runner 32 in the prior art position of arc runner 320, since such positioning would produce the undesirable result discussed above.

A further advantage resulting from the retardation of the ends of the upwardly moving arc is that the center of the arc may move upwardly into the arc chute faster than the ends of the arc are moving up their respective arc runners. This fact allows the arc to be effectively lengthened and thus aids in extinguishment. Thus, and as shown in FIGURE 8, with the arc runners 32 and 33 positioned directly in front of the vertical portions 41a and 41b of blow-out coil 41, so that the magnetic flux affecting these runners is at a minimum compared to the flux in the center of the arc chute (see FIGURE 7), the roots 401 and 402 of arc 403 will progress slower up the chute than the center of the are which is influenced by the maximum flux. Hence, the are 403 will be effectively lengthened and thereby aid extinguishment (the extended length of are 403 is to be compared with a length of arc 404 which would exist if the roots of the arc travelled at the same rate as the center of the arc).

It should be noted that either one or both of the arc runners 32 and 33 may be positioned in accordance with the teachings of the instant invention, with the result being a desirable lengthening of the arc. However, in the preferred embodiment, both are runners are so positioned in order to prevent premature arrival of either end of the arc at the top of its respective runner. Also, the controlled positioning of the are runners in accordance with the teachings of this invent-ion may be accomplished within an arc chute which utilizes only one blow-out coil 41, face Wound on one surface 16a of the arc chute l6.

FIGURES 5, 5a and 6 show the controlled positioning of arc runners 32 and 33 relative to the blow-out coils 41 in circuit breakers utilizing magnetic core structures of varying configuration. As is explained in copending application Ser. No. 452,453 filed Apr. 23, 1965 in the name of William A. Carter and assigned to the assignee of the instant invention, the various iron core configurations produce unexpected magnetic and electrical results which improve the operating characteristics of the circuit breakers in which they are used. For the purposes of this invention it is sufficient to note that the arc runners 32 and 33 in FIGURES 5, 5a and 6 may be selectively positioned with respect to the blow-out coils 41 to achieve the results discussed immediately above. From FIGURE 7 it can be seen that the ends of curves 100, 101, 102, 103 and 104 (which curves correspond to the iron core configuration of FIGURES 4 and 4a, 5, 5a, 6, and 4b, respectively) dip sharply in the regions immediately adjacent the arc runners 32 and 33. Thus it is apparent that the controlled positioning aspect of the arc runners in accordance with the teachings of the instant invention may find application in combination with the advantageous iron core configuration of the aforementioned copending application.

Thus there has been described a novel magnetic air circuit breaker which includes a face wound blow-out coil. Furthermore, by means of a controlled spacial orientation of the arc runners of such circuit breaker with respect to the face wound blow-out coil, the magnetic flux and resultant force appearing in the vicinity immediately adjacent the arc runners may be substantially varied so that the velocity of the ends of an are moving upwardly through the associated arc chute may be substantially reduced to prevent lingering of the ends of the arc at the tops of their respective arc runners.

Although I have described my invention with a certain degree of particularity, it is to be understood that the present disclosure has been made only by way of example and that numerous changes in the examples of construction and the combination and arrangement of parts may be resorted to without departing from the sphere and scope of the invention as hereinafter claimed.

What is claimed is:

1. A circuit breaker comprising a pair of cooperating contacts, a substantially rectangular arc chute positioned to extinguish an are drawn between said contacts upon separation thereof, said arc chute having a pair of opposite interior ends and first and second opposite faces joining said opposite interior ends, blow-out means energized by said are for urging said arc into said are chute, said blow-out means including a face wound blow-out coil, said blow-out coil being positioned along said first face of said arc chute, a first and second arc runner positioned at said opposite interior ends of said arc chute, said blow-out means generating a magnetic field within said arc chute when said blow-out coil is energized, said magnetic field being substantially less in vicinities adjacent said opposite interior ends of said are chute than in a vicinity intermediate said opposite interior ends of said arc chute, at least one of said arc runners being selectively positioned within said arc chute within one of said vicinities which are adjacent one of said opposite interior ends of said are chute, whereby said one of said arc runners will be subjected to a magnetic field which is substantially less than the magnetic field in said vicinity intermediate said opposite interior ends.

2. A circuit breaker comprising a pair of cooperating contacts, a substantially rectangular arc chute positioned to extinguish an arc drawn between said contacts upon separation thereof, said arc chute having a pair of opposite interior ends and first and second opposite faces joining said opposite interior ends, blow-out means energized by said are for urging said arc into said arc chute, said blow-out means including a face wound blow-out coil and iron core, said blow-out coil being positioned along said first face of said are chute, said iron core being substantially rectangular in shape and being positioned to surround the outer perimeter of said are chute, the plane of said iron core being transverse to the plane of said blow-out coil, a first and second arc runner positioned at said opposite interior ends of said are chute, said blow-out means generating a magnetic field within said are chute when said blow-out coil is energized, said mag netic field being substantially less in vicinities adjacent said opposite interior ends of said arc chute than in a vicinity intermediate said opposite interior ends of said are chute, at least one of said are runners being selectively positioned within said are chute within one of said vicinities which are adjacent one of said opposite interior ends of said are chute, whereby said one of said are runners will be subjected to a magnetic field which is substantially less than the magnetic field in said vicinity intermediate said opposite interior ends.

3. A circuit breaker comprising a pair of cooperating contacts, a substantially rectangular arc chute positioned .to extinguish an are drawn between said contacts upon separation thereof, said are chute having a pair of opposite interior ends and first and second opposite faces joining said opposite interior ends, blow-out means energized by said arc for urging said are into said arc chute, said blowout means including a face wound blow-out coil, said blow-out coil being positioned along said first face of said arc chute, a first and second arc runner positioned at said opposite interior ends of said are chute, said blow-out means generating a magnetic field within said are chute when said blow-out coil is energized, said magnetic field being substantially less in vicinities adjacent said opposite interior ends of said arc chute than in a vicinity intermediate said opposite interior ends of said arc chute, said first and second arc runner being respectively selectively positioned within said arc chute within said vicinities which are adjacent said opposite interior ends of said arc chute, whereby said arc runners will be subjected to magnetic fields which are substantially less than the magnetic field in said vicinity intermediate said opposite interior ends.

4. A circuit breaker comprising a pair of cooperating contacts, a substantially rectangular arc chute positioned to extinguish an arc drawn between said contacts upon separation thereof, said arc chute having a pair of opposite interior ends and first and second opposite faces joining said opposite interior ends, blow-out means energized by said arc for urging said are into said are chute, said blow-out means including a face wound blow-out coil and an iron core, said blow-out coil being positioned along said first face of said are chute, said iron core being substantially rectangular in shape and being positioned to surround the outer perimeter of said are chute, the plane of said iron core being transverse to the plane of said blow-out coil, a first and second arc runner posi tioned at said opposite interior ends of said are chute, said blow-out means generating a magnetic field within said arc chute when said blow-out coil is energized, said magnetic field being substantially less in vicinities adjacent said opposite interior ends of said are chute than in a vicinity intermediate said opposite interior ends of said are chute, said first and second arc runner being respectively selectively positioned within said arc chute within said vicinities which are adjacent said opposite interior ends of said arc chute, whereby said are runners will be subjected to magnetic fields which aresubstantially less than the magnetic field in said vicinity intermediate said opposite interior ends.

5. A circuit breaker comprising a pair of cooperating contacts, a substantially rectangular arc chute positioned to extinguish an arc drawn between said contacts upon separation thereof, said arc chute having a pair of opposite interior ends and first and second opposite faces joining said opposite interior ends, blow-out means energized by said are for urging said are into said are chute, said blow-out means including a face wound blow-out coil, said blow-out coil being positioned along said first face of said are chute, said blow-out coil having first and second portions parallel to said first face of said are chute, said first and second portions of said blow-out coil being positioned at said opposite interior ends of said are chute, said blow-out coil generating a magnetic field within said are chute when said blow-out coil is energized, said magnetic field being substantially less in vicinities adjacent said opposite interior ends of said are chute than in a vicinity intermediate said opposite interior ends of said are chute, a first and second arc runner positioned at said opposite interior ends of said are chute, a portion of at least one of said are runners being positioned within a plane which is transverse to the plane of said blow-out coil and which intersects said first portion of said blow-' out coil, the exact positioning of said portion of said one of said are runners within a plane which is transverse to the plane of said blow-out coil and which intersects said first portion of said blow-out coil minimizing the magnetic field intensity which affects the surface of said one of said are runners when said blow-out means is energized.

6. A circuit breaker comprising a pair of cooperating contacts, a substantially rectangular arc chute positioned to extinguish an are drawn between said contacts upon separation thereof, said arc chute having a pair of opposite interior ends and first and second opposite faces joining said opposite interior ends, blow-out means energized by said are for urging said are into said arc chute, said blow-out means including a face wound blow-out coil and an iron core, said blow-out coil being positioned along said first face of said are chute, said iron core being substantially rectangular in shape and being positioned to surround the outer perimeter of said are chute, the plane of said iron core being transverse to the plane of said blow-out coil, said blow-out coil having first and second portions extending through said iron core parallel to said first face of said are chute, said first and second portions of said blow-out coil being positioned at said opposite interior ends of said are chute, said blow-out coil generating a magnetic field within said arc chute when said blow-out coil is energized, said magnetic field being substantially less in vicinities adjacent said opposite interior ends of said are chute than in a vicinity intermediate said opposite interior ends of said are chute, a first and second arc runner positioned at said opposite interior ends of said are chute, portions of said first and second arc runners being positioned within planes which are transverse to the plane of said blow-out coil and which intersect said first and second portions of said blow-out coil respectively, the exact positioning of said portions of said first and second arc runners within planes which are transverse to the plane of said blow-out coil and which intersect said first and second portions of said blow-out coil, respectively, minimizing the magnetic flux which afi'ects the surface of said first and second arc runner when said blow-out means is energized.

7. A circuit breaker comprising a pair of cooperating contacts, a substantially rectangular arc chute positioned to extinguish an arc drawn between said contacts upon separation thereof, said arc chute having a pair of opposite interior ends and first and second opposite faces joining said opposite interior ends, blow-out means energized by said are for urging said are into said arc chute, said blowout means including a first and second face wound blowout coil, said blow-out coils being positioned in planes along said opposite faces of said are chute, each of said first and second blow-out coils having first and second portions, respectively, said first and second portions of said first and second blow-out coils being positioned at said opposite interior ends of said are chute, a front and rear arc runner positioned at said opposite interior ends of said are chute, said blow-out means generating a magnetic field within said are chute when said blow-out coils are energized, said magnetic field being substantially less in vicinities adjacent said opposite interior ends of said are chute than in a vicinity intermediate said opposite interior ends of said arc chute, at least one of said are runners being selectively positioned within said are chute within one of said vicinities which are adjacent one of said opposite interior ends of said are chute, whereby said one of said arc runners will be subjected to a magnetic field which is substantially less than the magnetic field in said vicinity intermediate said opposite interior ends.

8. A circuit breaker comprising a pair of cooperating contacts, a substantially rectangular arc chute positioned to extinguish an arc drawn between said contacts upon separation thereof, said arc chute having a pair of'opposite interior ends and first and second opposite faces joining said opposite interior ends, said blow-out means energized by said arc for urging said are into said are chute, said blow-out means including a first and second face wound blow-out coil and an iron core, said blow-out coils being positioned along said opposite faces of said are chute, said iron core being substantially rectangular in shape and being positioned to surround the outer perim eter of said are chute, the plane of said iron core being transverse to the plane of said blow-out coils, each of said first and second blow-out coils having first and second portions respectively which extend through said iron core substantialily transverse to the plane of said iron core, said first and second portions of said first and second blowout coils being positioned at said opposite interior ends of said are chute, said blow-out coils generating a magnetic field within said are chute when said blow-out coils are energized, said magnetic field being substantially less in vicinities adjacent said opposite interior ends of said are chute than in a vicinity intermediate said opposite interior ends of said are chute, a front and rear arc runner positioned at said opposite interior ends of said are chute, at least one of said front and rear arc runners having a portion thereof positioned in a plane extending between the first portion of said first blow-out coil and the first portion of said second blow-out coil, the exact positioning of said one of said arc runners within a plane joining the first portions of said first and second blow-out coils minimizing the magnetic flux which affects the surfaces of said one of said arc runner when said blow-out means is energized.

9. A circuit breaker comprising a pair of cooperating contacts, a substantially rectangular arc chute positioned to extinguish an arc drawn between said contacts upon separation thereof, said are chute having a pair of opposite interior ends and first and second opposite faces joining said opposite interior ends, blow-out means energized by said arc for urging said arc into said are chute, said blow-out means including a first and second face Wound blow-out coil and an iron core, said blow-out coils being positioned along said opposite faces of said are chute, said iron core being substantially rectangular in shape and being positioned to surround the outer perimeter of said arc chute, the plane of said iron core being transverse to the plane of said blow-out coils, each of said first and second blow-out coils having first and second portions, respectively, which extend through said iron core substantially transverse to the plane of said iron core, said first and second portions of said first and second blow-out coils being positioned at said opposite interior ends of said are chute, said blow-out coils generating a magnetic field within said arc chute when said blow-out coils are energized, said magnetic field being substantially less in vicinities adjacent said opposite interior ends of said arc chute than in a vicinity intermediate said opposite interior ends of said arc chute, a front and rear arc runner positioned at said opposite interior ends of said are chute, said front are runner having a portion thereof positioned in a plane extending 10 between the first portion of said first blow-out coil and the first portion of said second blow-out coil, and said rear arc runner having a portion thereof positioned in a plane extending between the second portion of said first'blow-out coil and said second portion of said second blow out coil, the exact positioning of said are runners Within the planes joining the respective first and second portions of said first and second blow-out coils minimizing the magnetic field which affects the surfaces of said front and rear arc runners when said blow-out means is energized.

References Cited UNITED STATES PATENTS 2,337,949 12/ 1943 Walle 200147 3,033,963 5/1962 Bohn 200147 3,070,681 12/1962 Wood 200-147 3,155,801 11/1964 Pokorny 200147 FOREIGN PATENTS 1,357,564 2/1964 France.

ROBERT K. SCHAEFER, Primary Examiner. ROBERT S. MACON, Examiner.

Claims (1)

1. A CIRCUIT BREAKER COMPRISING A PAIR OF COOPERATING CONTACTS, A SUBSTANTIALLY RECTANGULAR ARC CHUTE POSITIONED TO EXTINGUISH AN ARC DRAWN BETWEEN SAID CONTACTS UPON SEPARATION THEREOF, SAID ARC CHUTE HAVING A PAIR OF OPPOSITE INTERIOR ENDS AND FIRST AND SECOND OPPOSITE FACES JOINING SAID OPPOSITE INTERIOR ENDS, BLOW-OUT MEANS ENERGIZED BY SAID ARC FOR URGING SAID ARC INTO SAID ARC CHUTE, SAID BLOW-OUT MEANS INCLUDING A FACE WOUND BLOW-OUT COIL, SAID BLOW-OUT COIL BEING POSITIONED ALONG SAID FIRST FACE OF SAID ARC CHUTE, A FIRST AND SECOND ARC RUNNER POSITIONED AT SAID OPPOSITE INTERIOR ENDS OF SAID ARC CHUTE, SAID BLOW-OUT MEANS GENERATING A MAGNETIC FIELD WITHIN SAID ARC CHUTE WHEN SAID BLOW-OUT COIL IS ENERGIZED, SAID MAGNETIC FIELD BEING SUBSTANTIALLY LESS IN VINCINITIES ADJACENT SAID OPPOSITE INTERIOR ENDS OF SAID ARC CHUTE THAN IN A VICINITY INTERMEDIATE SAID OPPOSITE INTERIOR ENDS OF SAID ARC CHUTE, AT LEAST ONE OF SAID ARC RUNNERS BEING SELECTIVELY POSITIONED WITHIN SAID ARC CHUTE WITHIN ONE OF SAID VICINITIES WHICH ARE ADJACENT ONE OF SAID OPPOSITE INTERIOR ENDS OF SAID ARC CHUTE, WHEREBY SAID ONE OF SAID ARC RUNNERS WILL BE SUBJECTED TO A MAGNETIC FIELD WHICH IS SUBSTANTIALLY LESS THAN THE MAGNETIC FIELD IN SAID VICINITY INTERMEDIATE SAID OPPOSITE INTERIOR ENDS.

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