US1948658A - Device for extinction of electric arcs - Google Patents

Description

Feb. 27; 1934. G =GE 1 ET AL 1,948,658

DEVICE FOR EXTINCTION OF ELECTRIC ARCS Filed July 7, 1930 2 Sheets-Sheet 1 IllIl/IIII INS UL? 7706/ Feb. 27, 1934. G. GERIN ETAL- 1,948,658

DEVICE FOR EXTINCTION OF ELECTRIC ARCS Filed July 1 930 2 Sheets-Sheet 2 Patented Feb. 27, 1934 UNITED STATES PJATENT OFFICE omen Gerln, swim Application July Paul Joseph Branchu, and Tesmer, Grenoble, France I, 1930, Serial No. 466,322

France July 9, 1929 4 Claim.- (Cl. 200-144) This invention relates to a device for extinguishing electric arcs and to the use of this device for opening an electric circuit.

Its first object is to provide means to deaden the arc in the interior of an interrupting chamber or close to the same, by forcing the arc to enter a chamber, which is formed by a central electrode and an outer electrode and metallic rods or pieces which are insulated relatively to each other, and are interposed between these terminal electrodes and form the intermediary electrodes for the purpose of cooling the same, and of subdividing the arc or rupture into a plurality of serial arcs. Another object is to provide means for blowing out the arc and adapted to elongate the arc and impart to the are a rotary movement and force the arc to assume the shape of a spiral or a conical spiral.

Another object is to provide metallic parts corresponding to the form which the arc assumes when being rotatably displaced, and to assure the gradual increasing subdivision of the arc while it is being simultaneously elongated.

Another object is to so dimension and space said metallic parts as to assure a uniform distribution of the potential within the gap comprised,

between the two electrodes.

Another object is to interpose between the terminal electrodes and between the metallic parts serving as intermediary. electrodes, insulating parts forming segments of circles separated from each other and arranged concentrically in order to break certain parts of the arc and to amplify its elongation.

In the drawings Figure 1 is a vertical central section of an interrupter constructed and arranged in accordance with this invention.

Figure 1 is a detail transverse sectional view oi the lever h]. and lever '1 and their connections.

Figure 2 is a section of the same on line 2-2 of Figure 1.

Figure 3 is a similar section of a modification.

Figure 4 is a diagram of the electric circuit.

Figure 5 is a detail sectional view of mechanism for actuating the shunting contacts.

The circuit interrupter shown in Figure 1 is composed primarily of a base socket S on which are fixed by means of insulators 1, four posts C which carry the device for extinguishing the arc. This comprises a conical mass g of insulating material supported by the posts C. Said element a extends across and closes the upper end or an extinguishing chamber, the wall of which is formed by a metallic cylinder 0 on which is wound the coil d constituting the blowout coil, which is connected on the one hand with the cylinder c and on the other hand with the clamp s, as shown in Figure 4.

In the center of the mass q is also fixed a core e1 which carries a conducting tube e, which tube serves as the main fixed contact. A brush 62 mounted at the lower end of said tube e. Said tube forms the first electrode of the chamber a for extinguishing an are produced in the center 65 of the cylinder 0.

The core e1 is located in the center of an opening j in the part a, which opening serves as a draft chimrie y for cooling the apparatus and for improving in this manner the heat conditions.

Movable contacts h and i mounted on a lever hl contact with the tube e and the brush ez respectively.

The first portion h: of this lever which extends up to the level of the contact e:, is formed of two metallic jaws in (Fig. 5). The second portion is composed of a metallic member ha separated from the jaws i by the insulating blades he. This member In is cranked or bent at its inner end and constitutes a first auxiliary contact k.

The lever hi is freely pivoted about a shaft hi carried by bearings which are arranged within a frame hs fixed on the columns C by means of rings or collars.

The lever hi is controlled by a link rod A1 of a5 insulating material and a metallic handle A2, which is pivotally mounted as shown.

Another lever 7'1 is keyed on .the shaft hi and carries the second auxiliary contact a which is adapted to engage the first auxiliary contact k, carried by the lever hi. These two auxiliary contacts serve for short circuiting the blowout coil d.

The lever hi may turn freely about the shaft hi while the lever 1'1 turns with the shaft hand it is advisable to slightly brake the same to avoid that the lever ii should be carried along at the beginning of the movement of the lever ht. The lever a": is braked by blocking the same against the surface of the bearing by means of the small 1im ring washer 7'5 (Fig. 5).

On this last named lever hi there is fixed an abutment he adapted to come into interhook engagement with another abutment :iz fixed'on the lever 7'1 when the lever hi is slightly actuated.

Stops h! and a: are fixed on the frame h.- and are offset in such manner that at the end of the stroke of the levers hi and ii. the auxiliary contact between i and]: remains open as shown by no the positions otthe leversindottedlinesinl'ig- The auxiliary contact iis connected with the jaws h: 01' the lever through a shunt is.

The extinguishing device is completed by rods b, the upper ends 01' which are embedded in the insulating mass 0.

In one embodiment shown in Figure 2, the said rods are-arranged spirally. In the same figure there is shown a form 01' arcalso of spiral shape at:r,and itwillbeseenthzitinthiscasathe number of small arcs serially aligned between certain of the rods 1) which constitute-the path of the entire arc is considerably greater than it the entirearcextendedintheiorm of anordinarystraightrayiromctoc.

Such of the rods as are arranged in concentric circles form a series of condensers which are connected in cascade form. The capacities 0! these condensers may either be made equal through proper selection of the dimensions or the rods, or they may be equalized by proper selection 01' their number, assuring a uniform distribution of the electrostatic potential between the terminal electrodes e, c.

Figure 3 shows another embodiment of the arc extinguishing chamber where in addition to the metallic rods 21, there are provided concentrically arranged arcuate insulating partition walls t1, ta, ta, Inthiscase,theiormotthearc assumedby the latter at one instantwhile it is being shifted, willbethat form whichisshowniniulllines at 1 Theshapeoithespiralarczwith which it may be compared is shown in dotted lines.

The means for moving the contacts may be of any suitable construction. For the purposes of this specification suitable mechanism for this purpose is shown in Figure 5. and comprises an auxiliary contact 1' which is imder frictional control of a spring m locked by the nut a and thereby locking the lever is against the bracket ha. Itwillusuallyremainstationaryaslongasit isnotactuatedbythetappethwhichismounted on the extension of the lever ha. 1

As shown by the electric wiring diagram, Figures 1 and 4, the current when the circuit is closed passes through the central tube e and the principal contacts 2: and i, and leaves through conductor i1 and the bushing s. 11', however, the brushes are opened, the current passes through the spark protectors e and h and through the conductors in and auxiliary contacts I: and i which are arrangedior shortcircuitingthecoil d so as to deprive the coil of current. When, however, these also are opened, the current passes through the spark protectors c and it through the conductor (1: and through the blowout coil d, conductor d and bushing In all cases the spark protectors h are always insulated with respect to the principal contact e: because the lever which carries it is formed of two parts In and Ila-which are insulated from each other. I

The operation of the device is extremely simple and will readily be understood. The destruction of thearctakesplacebetweenthecentral rode and the spark protector h, after the principal contacts ed and i have been opened. This are is subjected to an electrodynamic blow produced by the coil d after the short circuit of the latter has been relieved through the auxiliary contacts and k.

The operation of the auxiliary contact calls for some further statement. The contacts I: are

displaced with the leverju while the contact 1 is displaced with the lever i1, and lags, for it is not actuated directly. It is advisable to make surethatthislagging eflectashas beenstated above, should be produced by a supplementary friction engagement for slowing down the rotation of the shaft '14- Owing to this condition, the auxiliary contacts 1', k are open after a very short stroke of the lever hi. However, the lever '1 is operated by means of abutments he, 1: which are fixed on the levers hr and 7'1 respectively. At the end of the stroke of the lever hi the auxiliary contacts 11'): remain open owing to the disengagement of the stop abutments h: and 7'; corresponding respectively to the levers hi and 7'1. The opening pomtion is shown in dotted lines.

It will be understood that upon closure of the lever hr the auxiliary contacts a, k are closed immediately and that the electrodynamic blowout becomes effective only on the extinguishing spark. Upon closure the lever 71 resting originally in stationary condition and the lever h:

short-circuited and it has no eflect on the are. which will be extinguished between the lightning arresters h, e.

When under the sheet of this electrodynamic blowout produced by the coil d, the arc is deformed, producing hence a band which is prolonged and which very rapidly'reaches the cylinder c. At this instant the arc Jumps approximately in radial direction between e and c.

. On the other hand, the convolutions of the coil being axial,- the are necessarily must be shifted on a circular path by turning about the central rod e. During this rotary movement, it upin thetorm otaspiraloroia conical spiral, a form which corresponds to the dynamic curve of equilibrium.

"As the arc gets gradually longer, its breaking upintosmallpartsalsobecomesgraduallymore pronounced.

Finally, it between the end electrodes not only themetallicrodsbareinthepath,butalso insulating partition walls t1, ta, is, there is produced an amplification ot the elongated are as indicated in Figure 3 at v and this elongation also gradually increases. In this case, however, the breaking-up does not proceed quite that far and for this reason, this device itself is not applied as often as when there is obtained an elongation of the arc sumcient to make sure the cutting oi the are under a predetermined intensity and a certain voltage.

By the use of metallic rods, combined with the rotary movement of the are into spiral shape, it will be seen that in the same scope or i'rame, there may be produced a much greater length of arc than that which corresponds to the distance between the electrodes, and, therefore, it is ieasible to interpose in its path, a number of electrodes of intermediary character and this number is much greater than the number which could beappliedtothe ordinarypathoithearcinths breakageotadeviceoithischaracterisdependent upon the increase elongating the arc, cutting ofl. the arc, which is practically more important than that with the devices heretofore employed by means or the interrupter of gmt power and small dimensions.

inbreakingupand we have obtained a power of The essential advantage or the device forming m the subject of the present invention with respect to what is known in this line, is that the elongation of the are obtainable while it is rotatively displaced, is a very great one without making necessary the provision of an interrupting chamber having extremely large dimensions for this purpose. The arc is elongated more and more in proportion to the degree of its rotary displacement. Furthermore, due to the combination described, there is produced simultaneously with the subdivision of the arc due to the interposition of intermediatelyelectrodes between the terminal electrodes, intermediary electrodes, it results that the breakage should be more and more abrupt in proportion to the elongation of the arc, due to the fact of such elongation and also to the arrangement of the intermediary electrodes.

What we claim, is:

1. In a device for extinction of an electric are. a chamber for the rupture of the arc having a conducting wall forming a first electrode, a second electrode in said chamber to produce an are between same and the wall of the chamber, a blowout coil on said first electrode producing an axial field in the space between the said two electrodes, one electrode enveloping the other and the length of the arc path for one revolution of the are being greater on one electrode than the other, so that the path traversed by the are at one turn under the eflfect of the blowout field is greater on the enveloping electrode than on the enveloped electrode, and is spiral.

2. In a device for extinction of an electric arc, a cylinder to form an arc-breaking chamber and having a wall forming one electrode or the are,

a central fixed contact, a movable contact, means to close and to open said contacts, windings around said cylinder, means to energize said windings while the said contacts are in opened position, and means in said cylinder between said fixed contact and said wall for elongating the spiral arc resulting from the electrodynamic blow produced by the windings after the short circuit of the latter has been relieved.

3. In a circuit breaker, an arc-rupture chamber, comprising a conducting wall forming an electrode and an insulating mass extend-- ing across the chamber at one end of said wall, metal rods arranged in said chamber to efiect distribution of the electro-static potential in said chamber, one end of each of said rods being embedded in said insulating mass, said insulating mass having a central opening, fixed contacts, a central rod to support the fixed contacts and to form one electrode of the arc, and windings around said wall of said chamber, to ensure the electrodynamic blasting and the winding up of the arc in the shape of a spiral line. 4. In a circuit breaker, an arc-rupture chamber, a central rod, therein forming one electrode, insulating tubular partitions in the said chamber arranged to provide tortuous paths to amplify the elongation of the arc, and means to create an electrodynamic field in said chamber and to spirally force the are around said elec trode rod.

GASTON. GERIN.

PAUL JOSEPH BRANCHU.

STANISLAS TESZNER.

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