US2443650A

US2443650A - Circuit interrupter

Info

Publication number: US2443650A
Application number: US555967A
Authority: US
Inventors: William E Berkey
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1944-09-27
Filing date: 1944-09-27
Publication date: 1948-06-22
Anticipated expiration: 1965-06-22

Description

June 22, 1948. w E BERKEY 2,443,650

CIRCUIT' INTERRUPTER Filed Sept. 27, 1944 2 Sheets-Sheet 1 j@ j. Egg 1725.3. 17324.

@Assays Faecs 2 2 j W y W 4 4 7 4S I-1 5 5 *27 1 1 75 af f3 W 3* l GAS "l/O l///V6` l 13 2@ f4 wlNEssEs: I VII INVENTOR M'lizamensg. A? m June 22, 1948.

' lNvENToR Wil/iam E 5er/hy.

BY 9J q 2 ATTORNEY Patented June 22, 1948 UNIT ED STATES GfFF'lC-El y CIR'CIT IN TERRUPTER. William Ef, Berkey, Forest Hills; Pa., assignorto Westinghouse Electric Corporation, VEast Pittsburgh, Pal, a corporation of Pennsylvania Application September 27, 1944, Serial No. `555,967

7 Claims. 1

'IEhisv invention yrelates to circuit 'interruptera in general, fand,- more particularly, to arc extinguishing structures therefor.

AA general object is 'to provide an improved circ'nt'interrupter in which an arc is established and rotated. Preferably during the rotation thereof-the arc yis forced against Vbaiiie means disposed-directly inthe-path of the rotating arc.

Another object is to provide an improved circuitinterrupterof the rotating arc type Vin which f thefcontact structure has anfimproved 'constructions Further objects and advantages will readily becomeapparent from a reading of Athefollovvingspeciiication taken in conjunction with the drawings, in which:

Figures 1 4. theoretically illustrate the principles involved in my invention;

Fig. 5 is a sectional view taken along the line V--V of Fig. 6;

Fig. 6'is a vertical sectional View taken substantially along the line VI--V of Fig. 5, the parts .being shown in the closed circuit position;

Figs. 7 and 8 illustrate modied types of baflle platevconstruetions;

(Fig. 9 is an enlarged plan View of a modified type otcontact construction;

Fig. 10 is a sectional View taken along the line X-X of Fig. 9;

Fig. l1 is a sectional View taken along vthe line XI-XI of Fig. 12; and

Fig. 12 is another modiiied type of contact construction.

Referring to the drawings and, more particularly, to Figs. 1 and 2 thereof, it will be noted that an arc I is established by means not shown between the

cooperable contacts

2, 3, the arc extending through a. hole 4 provided in a baile plate 5 composed of a suitable gas evolving inaterial such as horn fiber or boric acid. The @baffle platey 5 is moved toward the left as indicated by the arrow 5a by suitable means not shown so that the edge E oi the hole 4 engages the arc Iv causing the latter to assume a bowed shape as shown in Fig. 2. The arc I causes gases to 'be evolved from the plate 5 which react upon the arc forcing it in the direction of the arrows 1 of Fig. 2. These forces caused by the gas evolving from the plate 5 do not necessarily have aldi-rection which is perpendicular to the axial length of the arc but may have a random direction as they act against the are I.

Thus the constructions shown in Figs. 1 and 2'illustrate the forces acting upon the arc which result 'from physically movingvthe Ybaiile plate s5 composed of a suitable gas evolving material laterally VVso that one .edge ofthe hole 4engages the'arcl.

The construction shown in Figs. Band Liz-illus.- trate lan arrangement whereby thearc vI .moved between the

cooperablecontacts

2, 3 .by means offa transverse magnetic field: 'passing :perpendicular-ly into the planer of the paper. Consequently, the arc movesin a direction that. is not only perpendicular to its `length but alsolinffa direction which is perpendicular to the magnetic neld.- The forces exerted bythe magnetic field onthe larc -I lare designated by the arrows Band are always/in 'adirection perpendicularly .to the axial' lengthl ci' the arc I and: uniformiyy distibutedalong its length. .As the arc lI is moved toward the right by the action of the magnetic eld,-fthe-fbaflle plate 5in vthis instance .remaining stationary,zthe are I will` again engage-the edge '6 of thefplate 5, which is composed -of a suitable gas evolving material.

The-arc Iagain'assumes a bowed-shape: as shown in Fig- 4 but it `vvvillnbe observed that in this. instance the= arrows` 8 sti-lll react uponthe arc Iv in afdirection Vperpendicularly -toits axial length and tend '-to intimately force the arcI against thebaflie plate 5 to-causea greater evolutionfof` gas lthan was the casein Fig. 2. results because of the uniform distributienet forces along the length of ithe arc. The arrows 1 again indicate the forces-exertedy by the gas evolved from` the plate 5. asa result of the Iin timate engagement of the arc I thereon.

Consequently, from the examination of Figs. 1 4, it will beobserved-that the construction shown in Fig.. Lis far superior tothe construction shown in Fig. 2where only the lbaiile plate 5 is physically moved. In other Words by utilizing a magnetic eld the engagement between the arc I and the plate 5 is more effective and there correspondingly -vresults agreater evolution ofgas from ythe bafe plate 5. The greater evolution of. gasl consequently more readily effects the extinction of the arc I.

Thel use oi a ydirect-current eld results in an additional advantage. The reaction forces with a direct-current magnetic field to4 move thearc remain nite andlarger in magnitude as compared with an A.C. magnetic eld as the arc current yapproaches zero; If an alternating-currentl magnetic iield is used` then the reaction forces on the arc decrease faster as the current approaches Izero :because both the field and current are decreasing.

Figs. 5 and 6 show an embodiment of any incurrent source for energizing the eld coils 9.

I0, the radial magnetic eld which is thus set up between the magnetic core I3 and the pole plate I4 and indicated by the arrows I5 of Fig. 5 does not diminish in strength as a function of time.

the movable bridging contact I6 from the ringshaped contact I'I an arc I (Fig. 5) is established and rotated around the ring-shaped contacts I1, I8.

Disposed between the ring-shaped contacts I1, I8 are bale means of gas evolving material generallydesignated by the reference numeral I9 and disposed directly in the path of the rotating arc I which is initially drawn through a hole 4 of the baille means I9., In this instance the baille means I9 comprises a g inch thick fiber plate having 1%; inch diameter holes 4 provided therein adjacent its periphery as more clearly shown in Fig. 5.

It will be observed that in the closed circuit position, as shown in Fig. 6, the movable bridging contact I6 extends through one of the holes 4 provided in the insulating plate 29 of annular configuration and composed of gas evolving material.

-The terminal connections to the interrupter as shown more clearly in Fig. 6 comprise a terminal strip 2| connected by a screw 22 to the upper ring-shaped contact I8.` The-other terminal of the interrupter comprises a terminal strip 23 electrically connected by a screw 24 to the lower `ring-shaped Contact I'I.` The current passing-between the contacts I8, II may be either direct current or alternating current. If alternating current is employed, and the'eld coils 9, I0 are energized from an 4alternating-current source, preferably the iield coils would be serially connected with the contacts I-l, I8 to an alterhating-current source. 1 e

The contact structure may be secured in place by an insulating sleeve 25 which surrounds an annularly shaped block of insulating material 26, the latter lhaving an annular groove 21 into which is xed the lower ring-shaped contact I'I. The annular `plate 29 is held in position by two

insulating sleeves

28, 29 which surround the core I3. An insulating cap 30 may be provided having apertures 3l formed therein to permit an escape of the gases formed during the rotation of the arc I. The eld coils 9,

I0 surround cores

32, 33 respectively formed of suitable magnetic material, such as iron, whichV extend between the pole plates I4, 34. If desired the contact structure may be biased toward the open circuit position by means of a compression spring 35 interposed between the cap 3l!l and a flange 36 integrally formed with the movable bridging contact I6. A bracket 37 secured by a screw 38 to the cap 30 may be employed to guide the movement of the bridging contact I6. Suitable actuating means not shown may be employed to eiect longitudinal movement -of the bridging contact I6.

Consequently, upon the upward movement of` contacts I8,` I'I, several times, jumping from hole The arc I may jump from hole to hole as it iotates around the ring-shaped contacts I8, I'I each time striking an edge 6 of the holes 4 as shown in Fig. 4 to cause a considerable evolution of gas. The extent of rotation depends upon the force F (Fig. 5) which acts on the rotating arc I, and the force F in turn depends upon the magnitude of the current being interrupted and the radial magnetic eld strength.

Actually the arc I may circle the ring-shaped to hole during the rotation thereof.

' In place of the gas evolving nber plate 20, insulating

plates

39 or 40 as shown in Figs. 7 and 8 may be employed.

` The fiber plate 39 in Fig. 7 has provided there- .y in three arcuately-shaped slots 4I and the fiber plate 49 has a single arcuately-shaped slot 4I.

Preferably, each of the ring-shaped contacts I8, Il' has either a construction as shown in Fig. 9 or a construction as shown in Fig. 12. -The modified construction shown in Fig. 9 comprises a ring-shaped contact 42 having a hole 43 provided therein through which the bridging contact I9 extends. The contact 42 has a plurality of concentrically disposed annular grooves 44 provided therein. The depth of the grooves 44 was 1A; inch and the width of the grooves 44 was 12 inch, as illustrated in the cross section of Fig. 10. Such a construction gave excellent results.

Another contact construction which gave very good results is that shown in Figs. 11 and 12 wherein a plurality of radially disposed grooves 45 were provided in the modied contact construction 46. The depth of the radial grooves 45 was 1/8 inch and the spacing between adjacently disposed grooves 45 was substantially 1A; inch.

Therabove two contact constructions facilitate arc rotation inasmuch as the arc rotates by jumping from point to point in its rotative movement. A portion of the arc length near the terminal end of the arc bows down in the direction of arc travel, and the above two constructions take advantage of this phenomena by facilitating the jumping of the arc from a previous point of arc termination to a point adjacent to which the bowed portion of the arc neared the contact. This jumping phenomena continues dur-ing arc rotation. y

Another important consequence of the reaction force F exerted by the magnetic radial eld on the arc I during the rotation thereof is to produce acceleration of gas and thereby produce an air blast which carries away the arc gases. The field will move the arc terminals as far as the holes in the barrier plate 20 will permit, such motion increasing the arc voltage together With the alc length. As mentioned previously, restriking between successive holes 4 may result, thus causing the arc I to jump from hole to hole as it rotates around the contacts Il, I 8. v

From the foregoing description it will be apparent that I have provided an improved circuit interrupter of the rotating arc type in which the arc is drawn through a hole in suitable baiile structure and rotated, the arc during the rotation thereof striking against the side of the hole to produce a considerable evolution of gas. `I have illustrated improved contact constructions and have shown three different types of baffle structures which may be employed. By utilizing the particular construction disclosed in conjunction with rotative arc movement. contact burning is minimized, turbulence is in creased, and considerable arc travel is possible with a structure of minimum overall size.

Although I have shown and described specific structures, it is to be clearly understood that the same were merely for the purpose of illustration and that changes and modifications may readily be made therein by those skilled in the art without departing from the spirit and scope of the appended claims.

I claim as my invention:

l. In a c-ircuit interrupter, a pair of cooperable ring-shaped contacts, means for establishing an arc between the ring-shaped contacts, means for establishing a radial magnetic field for causing rotation 0f the arc around the ring-shaped contacts, and at least one of the contacts having a plurality of concentrically disposed annular grooves provided thereon.

2. In a circuit interrupter, a pair of cooperable ring-shaped contacts, means for establishing an arc between the ring-shaped contacts, means for establishing a radial magnetic field for causing rotation of the arc around the ring-shaped contacts, and at least one of the contacts having a plurality of radially disposed grooves provided thereon.

3. In a circuit interrupter, a pair of separated endless ring-shaped contacts immersed in air, an insulating plate disposed between the contacts yand having a plurality of spaced holes disposed therein, means for establishing an arc between the separated contacts through one of the holes, means providing a radial magnetic eld to cause rotation of the arc around the endless ringshaped contacts, and said holes in the insulating plate being of substantially uniform size and spaced substantially equidistant about a circular path so that as the arc rotates around the contacts it jumps from hole to hole and extinguishing action at the edges of the holes is immediately brought to bear upon the rotating arc.

4. In a circuit interrupter, a pair of separated endless ring-shaped contacts immersed in air, an insulating plate disposed between the contacts and having a plurality of spaced holes disposed therein, means for establishing an arc between the separated contacts through one of the holes, means providing la radial magnetic field to cause rotation of the arc around the endless ringshap'ed contacts, and said holes in the plate being disposed symmetrically about a circular path so that as the arc rotates around the contacts it jumps from hole to hole and extinguishing action at the edges of the holes is immediately brought to bear upon the rotating arc.

5. In a circuit interrupter, a pair of separated endless ring-shaped contacts immersed in air, an insulating plate disposed between the contacts and having a plurality of spaced holes disposed therein, means for establishing an arc between the separated contacts through one of the holes, means providing a radial magnetic eld to cause rotation of the arc around lthe endless ringshaped contacts, the holes in the insulating plate being disposed in a circular path and relatively closely together so that as the arc rota-tes around the contacts it jumps from hole to hole and there being a plurality of holes in the rst half turn around the ring-shaped contacts so that eX tinguishing action at the edges of the holes is immediately brought to bear upon the rotating arc.

6. In a circuit interrupter, a pair of cooperable ring-shaped contacts, means for establishing an arc between the ring-shaped contacts, means for establishing a radial magnetic field for causing rotation of the arc around the ring-shaped contacts, -at least one of the contacts having a plurality of concentrically disposed annular grooves provided thereon, and an insulating plate dis- ;posed between the ring-shaped contacts with a plurality of spaced holes therethrough so that the arc jumps from hole to hole as it rotates around the contacts.

7. In a circuit interrupter, a pair of cooperable ring-shaped contacts, means for establishing an arc between the ring-shaped contacts, means for establishing `a radial magnetic field for causing rotation of the arc around the ring-shaped contacts, at least one of the contacts having la plurality of radially disposed grooves provided thereon, and an insulating plate disposed between the ring-shaped contacts with a plurality of spaced holes therethrough so that the arc jumps from hole to hole as it rotates around the contacts.

WILLIAM E. BERKEY.

REFERENCES CITED The following references are oi record in the le of this patent:

UNITED STATES PATENES Number Name Date 1,039,305 Hewlett Sept. 24, 1912 2,095,301 Wilcox Oct. 12, 1937 2,112,033 Lingal et al Mar. 22, 1938 2,138,391 Van Sickle Nov. 29, 1938