US1751233A - Circuit interrupter - Google Patents

Description

March 18, 1930. o. H. ESCHHOLZ CIRCUIT INTERRUPTER Filed Dec. 13.

ATTORNEY INVENTOR Ctto H. Eschholz BY M WITNESSES:

Patented Mar. 18, 1930 UNITED STATES @FFEQE OTTO H. ESCHHOLZ, OF WILKINSIBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE CIRCUIT IN TERRUIPTER Application filed December 13, 1922. Serial No. 606,570.

My invention relates to electrical circuit interrupters, and more particularly to the type employing means for extinguishing an electrical are between the contact members.

An object of my invention is to provide a circuit interrupter or breaker in which the gases generated by an are between the contact members are employed to extinguish the arc and to prevent its reformation after the current wave has passed through zero.

Another object of my invention is to provide means for preventing the reformation or re-ignition of an electric are after the electric current has passed through the zero value by reducing the intensity of the electrostatic field near the contact members.

Another object of my invention is to provide a circuit breaker with means for imparting, to an arc stream, a strong directional impulse in a predetermined path through the sudden release of confined gases.

A further object of my invention is to provide a shielding means for the contact mem bers which also acts as a chamber for confining the gases produced by an electric are passing between the contact members.

To accomplish the above mentioned objects, I mount a shield near the end of each contact member. When the contact members 8 are closed, the surfaces of these shieldsengage each other forming a chamber. The bases of the shields are resiliently connected to the contact members.

The creation of an are between the contact members results in the generation of gases, which cause the walls of the chamber to expand against their resilient supports. At the same time the movement of the contact members tends to further separate the 9 surfaces of the shields. One portion of each shield piece is shorter than the remainder of the shield and the short sections of the'two complementary shields are placed in registry. The efiect of the combined forces tending to separate the shield surfaces is to cause the shorter sections to separate with an explosive action in advance of the remaining sections. c

The contact members are provided with means for facilitating the arc terminal to travel to a point adjacent to the associated short sections of the shields. The escape of the arc gases is given a predetermined direction, this movement being such that the escaping gases impart a strong directional impulse to the arc stream, tending to carry the arc stream away from the contact and thus prevent a re-establishment of the are after the current has reached zero value.

The shields are preferably of substantially spherical form as such a shape results in a more uniform potential gradient between the contact structures upon separating contact members. A pointed electrode or shield produces an uneven potential gradient which facilitates a'break-down of the intervening dielectric and the re-establishing of the are after the current has passed through zero value.

In the accompanying drawings:

Figure l is a plan view of a contact mem ber equipped with a shield embodying my invention.

Fig. 2 is a cross sectional view of a contact giember and shield taken on line Hl[ll of ig. 1.

Fig. 3 is a view, similar to Fig. 2, of a con tact member equipped with a modified form of shield.

Similar reference numerals in the several views indicate like parts.

In the form of my invention shown in Figs. 1 and 2, a pair of relatively movable contact members 1 and 2 are provided with similar arcing shields 3 and 4, respectively. 'lfhese shields are of substantially ear shape, and are composed of a plurality of similar flexible sections 5 and several sections 6 and 7 of special shape which'are shorter than the sections 5. A broad band 8, secures the bases of the several sections to a strip of insulation 9 mounted on the contact member in such manner that the flexibility of the sections is not limited.

If desired, the insulation 9 may be omitted for a very low and uniform potential gradient between the contact members.-

The outer ends of the several sections'extend beyond the adjacent contact members, and define an opening 11 in each shield through which the contact members may project when in their closed position, as is shown in Fig. 2. During the operation of closing the contact members, the outer faces of the shields 3 and 4 meet in advance of the contact members and are deflected or crowded into a flattened position, but without the creation of openings in the walls of the shields.

A pair of arcing horns 12, 13 are mounted on contact members 1 and 2, respectively, adacent to the short sections 6 and 7 of the shields.

Upon the separation of the contact members, the electrical are 14, generated thereby, produces a quantity of arc gases which drives the walls of the shields 3 and 4 outwardly with a tendency to separate them.

At the same time, the mechanical movement of the separating contacts 1 and 2 also tends to separate the shields 3 and 4. Before actual separation takes place, a high gaseous pressure is generated within the shields.

This is shown in Fig. 2, where the first separation of the shields is taking place between the short sections 6 and 7. The oreation of this opening is accompanied by a rush of escaping gas.

Since the arc stream is directed close to this opening by the arcing horns 12, 13, it

is caught up and swept along by the escapinggas. The path of the arc stream is thereby increased, and, as the, current value passes through zero, arc re-establishment is prevented. In the meantime, the entire surfaces of the shields 3 and 4 have separated.

. In the modification of my invention shown in Fig. 3, the shield 15 is made to telescope within the shield 16. The surfaces of these shields are shortened, as at 17, in order to create an opening in advance of the separati on of the main shield members. The princlples involved in the operation of this modification of my invention are similar to those described in connection with the modification shown in Figs. 1 and 2.

It will thus be seen that I have invented a shield for relatively movable contact members which utilizes the arc gases generated by the separation of these members for imparting a predetermined blow-out force to the arc stream.

It will be apparent that various modifications may be made in the apparatus without departing from the spirit of the invention, as defined in the accompanying claims.

I claim as my invention:

1. In an electrical circuit interrupter the combination with a contact member for in terrupting a circuit, of a shield of resilient material associated therewith.

2. In an electrical circuit interrupter the combination with a contact member, of a resilient shield having portions of different lengths associated therewith.

3. An electrical circuit interrupter comprising a plurality of contact members, a resilient shield for each of said contact members, said shields forming a chamber upon the closing of said contact members.

4. An electrical circuit interrupter comprising a plurality of coacting contact members, a resilient shield for each contact member, the surfaces of the registering shields forming a chamber upon the closing of the contact members.

5. An electrical circuit interrupter comprising a plurality of contact members, a resilient shield for each contact member, the shields forming a chamber for confining the gases generated upon the occurrence of an are between the contact members.

6. An electrical circuit interrupter comprising contact members, cooperating shielding means for each of said contact members which, when in a closed position, comprise a chamber for confining the gases generated upon the occurrence of an arc between the contact members, and means for releasing said gases upon a predetermined separation of said contact members.

7. An electrical circuit interrupter comprising contact members, cooperating shielding means for each of said contact members which when in a closed position comprise a chamber for confining the gases generated upon the occurence of an are between the contact members, said shielding means having a vent for releasing said gases opened upon a predetermined separation of said contact members.

8. In an electrical circuit interrupter the combination with contact members, of resilient shielding means for confining the gases generated upon the separation of the contact members, said shielding means having a vent operative upon a predetermined relative movement of the contact members for allowing the escape of said gases.

9. In a mechanism for extinguishing an electric arc, a plurality of contact members, cooperating shielding-means for each of said contact members, said shielding means being provided with a vent, said shielding means operating to confine the gases generated upon the separation of the contact members until said vent is opened, said gases escaping through said vent.

10. In a circuit interrupting device a plurality of contact members, cooperating shielding means carried by each of said contact members, said shielding means forming a chamber about said contact members in advance of the closing of said contact members, and said shielding means preserving the chamber for a time after the separatlon of said contact members.

11. A circuit interrupting device comprising a plurality of contact members, symmetrical shielding means surrounding said OTTO H. ESOHHOLZ.

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