US2597257A - Electric switch - Google Patents

Description

May Z0, 1952 H. v. NYE

ELECTRIC SWITCH med June 11, 1948 INVENTOR BY( f M ATTORNEY iatented May 2G, 1952 UNITED STATES ATENT QFFICE ELECTRIC SWITCH Henry V. Nye, West Allis, Wis., assignor to Allis- Chalmers Manufacturing Company, Milwaukee, Wis., a corporation of Delaware Application June 11, 1948, Serial No. 32,455

(Cl. G-144) 7 Claims.

This invention relates in general to electric switches or circuit breakers, and to the control of arcs formed by the opening of arcing contacts. The principal objects of the invention are the provision of new and improved electric switches or circuit breakers and new and improved arc control means.

One way to control an arc formed by the opening of an electric switch is to have two stationary arc runners for directing the arc into an arc extinguishing chute. The circuit is broken by a movable arm that draws an arc from one arc runner and transfers it to the other arc runner. With this arrangement however, the arc hangs on to the movable member too long and excessive heating and melting of the member may occur. Another way to control an arc is by means of a movable arc runner that makes contact with another arc runner, the movable arc runner being swingable about a fixed pivot. But the space requirements of an arc runner swingable about a iixed pivot make it difiicult to reduce the overall size of the switch. Accordingly, another object of the invention is to provide an arc runner that will overcome the aforementioned difiiculties.

Another object of the invention is the provision of new and improved arc drawing and extinguishing means, comprising arc runners in which the arc is free to move upwardly on the arc runners as soon as the arc is initially drawn, and in which the space requirements are minimized.

Another object of the invention is to provide a construction and arrangement in which the movable arc runner will travel toward the discharge end of the arc extinguishing chute, as the arc is drawn.

Another object of the invention is to provide a construction and arrangement of the movable arc runner so the entire length of the arc is led into the chute by the motion cf the movable arc runner.

Another object is the provision of new and improved contact means.

Other objects will appear hereinafter as the description of the invention proceeds.

The novel features of the invention and how the objects are attained will appear from this specification and the accompanying drawing showing one embodiment of the invention and forming a part of this application, and all of these novel features are intended to be pointed out in the claims.

In the drawing:

Fig. y1 is a side elevational view of a switch or circuit breaker embodying the invention, certain enclosing Walls having been removed to better show theV arrangement of parts within;

Fig. 2 is an enlarged partial section taken on line II-II of Fig. 1;

Fig. 3 is an enlarged partial section taken on line III--III of Fig. l Fig. 4 is an enlarged partial section taken on line lV--IV of Fig. 1; and

Fig. 5 is an enlarged partial section taken on line V-V of Fig. l.

Referring to Fig. 1, the,l switch here shown comprises arc drawing means, as will appear, and an arc chute I, for receiving the arc, comprising any suitable walls of insulating material which may provide an enclosure open at the top and bottom. The chute may have suitably supported therein a series of spaced arc dividers 2 of any suitable material, as will be understood by those skilled in the art.

The arc drawing means comprises a stationary arcing contact member 3 and a composite movable contact member 4. The stationary arcing member 3 comprises an upwardly and outwardly extending arc runner 5 integrally formed with a stationary arcing contact portion 6, the stationary contact member 3 having a laterally extending base portion 'I that is supported by and attached to an end Wall 8 of the arc chute I. The upper end of the arc runner 5 is here shown as disposed between the wall 8 and the left hand end of the series of arc dividers 2. The base portion l is here shown as electrically connected, in series, with an arc blowout coil 9 to an electrical terminal il). The electrical terminal I 0 is in turn connected to a stationary main contact II. The stationary main contact II supports and cooperates with a stationary auxiliary contact means I2 here shown as comprising two contacts I2a, |21) as shown in Fig. 2. The main contact II, or that contact together With contacts IZa, 12b may be considered the principal stationary contact means. The contacts I2a, I2b are here shown as each provided with a projection 40 engaging the main contact II at opposite sides thereof. The contacts I2a, I2b are biased toward the stationary main contact II by. springs I3 held by screws I4. The auxiliary contacts I2a, I2b can therefore spread as a conducting main switch arm I5 here shown as comprising two parallel spaced members I5a, |51), forming part of the composite movable contact member 4, and here shown as swingable about a pivot I1, passes between and in engagement with the contacts I2a, I2b, to engage opposite sides of the main stationary contact II. The pivot Il may also serve as an electrical terminal for current flow to the switch arm I5. Movement of the contacts I 2a, 12b toward the main contact II is limited by suitable stops 4 I.

The members Icz, I5b are movable relatively to each other in the direction of the axis of a bolt 23, seen in Figs. 1 and 4, to an extent limited by the bolt 23, a nut 23a thereon, a spring 24 and a spring retainer 25, as shown in Fig. 4. The members Ia, i512 are thereby able to spread sufficiently to pass over and in engagement with the main contact II and yet pass between the auxiliary contacts I2a, I2b, as shown in Fig. 2.

It will be noted from the foregoing description that there are, as shown in Fig. l, three contacts adapted to be engaged by the main movable switch arm I5, namely, the stationary main contact I I, the stationary auxiliary contacts I2a, I2b and the stationary arcing contact portion 6.

The composite movable contact member 4 comprises besides the main switch members I5a, I5b, a floating arc runner I6. The arc runner I6 is of composite construction as here shown and is connected at one end to the members I5a, I5b by a composite pivot I8a, I8b, as will more fully appear. The other end I9 of the runner I'6 is slidably connected in a slot 26 of a guiding means 2I by a pin 22, as will more fully appear and as shown in Fig. 1 and Fig. 5. The guiding means 2| may be supported in any suitable way by the right hand end wall 8a of the arc chute. l.

The floating arc runner is here shown as comprising two parallel, spaced members I6a, I6b as best seen in Fig. 3 and Fig. 5. The two members I6a, I6b are desirably integrally jointed by a base member 26, thereby forming an integral inverted U-shaped channel member.

The base member 26 terminates at one end 45 so as to leave the right hand ends of the members I6a, 16h free, forming arms at opposite sides of the guiding means 2 I. As shown in Fig. 5, the pin 22 extends through both members I6a, I'6b. Spacing collars 46, 41 may be provided between the respective inside surfaces of the members I6a, IBb and the respectively adjacent sides of the guiding means 2l. The pin 22 may be held in position by cotter pins 48 through the pin 22, or in any other suitable way.

The base member 26 terminates at the other y end 49, short of the inner surface of the stationary arc runner 5, as seen in Fig. 1. This leaves the left hand ends of the members I6a, I6b free, forming arms at opposite sides of the members I5a, I5b. Since the movable arc runner comprises two members I6a, I6b and the movable main contact arm to which it is pivoted comprises two parallel members I5a, I5b, two pivot pins IBa, Ib are provided (see Fig. 3) the pivot pin I8a connecting the members I 5a and I5a and the pivot pin ISI) connecting the members I5b and I6b. As here shown the pins I 8ay and I'Bb have heads 50 which are disposed in respective recesses in the opposed inner faces of the members I5a, I5b, so as to leave those inner faces free and unobstructed for engagement with the opposite faces of the contact 6. The pins I 8a, I8b may be held in position by cotter pins as indicated.

The blowout coil 9 is disposed about a generally U-shaped magnetic core having a bight 2`I and having legs extending alongside the respective side walls of the chute I. One of the legs, 60, of the core 2l is indicated in Fig. 1. The blowout coil 9 provides a magnetic neld across the arc chute I for promoting upward movement of the arc (as viewed in Fig. l) that is, movement toward the discharge end of the arc chute I.

It will be evident that while making the arc runner I6 and the main contact I5 of double arm form has advantages, this construction is not essential. As far as the electrical functions of the switch are concerned, and particularly the operation of the arcing contact means thereof, single arm parts may be utilized.

The operation of the switch illustrated is as follows: When the switch is in the closed position as shown in Fig. l, the principal path for electric current, the path of least resistance, may be traced from the fixed pivot I1 to the movable main contact member I5 to the stationary main contact II, to the electrical terminal ID. If the current path is to be interrupted, the movable contact member' I5 is caused to swing clockwise about the pivot IT by any suitable means. This movement initially causes disengagement of the movable contact member I5 from the stationary main contact I I, without substantial arcing, leaving a current path through the movable contact member I5 and the stationary auxiliary contact I2. Further movement of the movable contact member I5 causes disengagement thereof from the auxiliary contact I2 thereby causing current to ow through the blowout coil 9 in series with the arcing contact 6 and the upper end of the movable contact member I5, which latter two contacts have not, as yet, separated. Still further movement of the movable contact member I5 causes disengagement of the latter from the arcing contact 6. An arc is thereby drawn, in a substantially horizontal direction, between the stationary arcing contact 6 and at least one of the members I5a, I5b, in the double arm construction illustrated. At the point of initial arcing, the members I5a, I5b may be provided with contact inserts 28 and 29 (see Fig. 1 and Fig. 3). The inserts 28 and 2S may be made of a metal having more desirable contact properties than those of the members IEa, |51). The arc will rise with one end on the stationary arc runner 5 and the other end momentarily on at least one of the members I5a, I5b from which it is quickly transferred to the floating arc runner I6, and, more particularly, to top 26 thereof. It will be understood by those skilled in the art that the arc rises due to the field set up by the arc itself which will be assisted by the blowout coil 9 if employed.

As the switch is opened the floating arc runner I6 will move relatively to the movable contact member I5, rotating counter-clockwise about the floating pivots I 8a, I8b, because the other end I9 of the movable arc runner I6 slides up the slot 20 of the guiding member 2I. This causes decrease of the angle A between stationary arc runner 5 and the floating arc runner I6. Also, the end I9 of the noating arc runner I6 is led deeper into the arc chute I (toward the discharge end of the chute) as the arc moves upwardly. The entire length of the arc is therefore led into the chute I and extinguished.

It will bc evident that as soon as contact is broken between the movable contact member I5 and the stationary contact 6, the so established arc will not hang on the upper end of the contact member I5 but will quickly transfer to the floating arc runner I6 and move upwardly along the runner I6 as the runner is swung about the floating pivots I8a, I 8b. Thus all the advantages of an arc runner swingable about a fixed pivot are retained while at the same time obviating its disadvantages. c

It will also be apparent that broadly, as far as the operation of the arcing contact means', comprising the arc runners 5 and I6, is concerned it is not material whether the fioating arc runner I6 is carried by a swingably mounted member such as movable contact member I5, or whether separating movement of the arc runners is obtained by any other suitable means, and/or the initial establishment of the arc takes place directly between portions of the contact 6 and fioating arc runner. Furthermore, the illustrated guiding means for causing a decrease in the angle formed between the are runners 5, I6 as the runners are separated to draw an arc, while specifically advantageous, may be replaced by any other suitable means for accomplishing that result as will readily occur to those skilled in the art.

From the foregoing it will be apparent to those skilled in the art that the illustrated embodiment of the invention provides a new and improved arcing contact means, arc control means, and electric switch, and accordingly accomplishes the objects of the invention. On the other hand it will also be obvious to those skilled in the art that the illustrated embodiment of the invention may be variously changed or modified, or features thereof, singly or collectively, embodied in other combinations thanthat illustrated, without departing from the spirit of the invention or sacrificing all of the advantages thereof, and that accordingly the disclosure herein is illustrative only, and the invention is not limited thereto.

It is claimed and desired to secure by Letters Patent:

l. Arcing contact means, comprising: rst and second conducting members cooperable to draw an arc between them upon separation thereof; an arc chute for receiving the arc drawn between said members, said chute having a discharge end; means for causing separation of said first and second conducting members, comprising a movable portion and a connection between one of said members and said movable portion whereby said one of said members is swingable with respect to said portion; and guiding means responsive to said separating movement for causing said one of said members to swing with respect to said portion and to actuate said member toward the discharge end of said chute, said guiding means comprising a relatively stationary part with respect to which said one of said members is slidable.

2. Arcingcontact means, comprising: first and second conducting members cooperable to draw an arc between them upon separation thereof; one of said members comprising an elongated channel of U-shaped cross section having a base forming an arc runner, a movable element disposed between arms at one end of said channel, and a connection between said element and said arms whereby said channel is swingable with respect to said elements; means for causing separation of said first and second conducting members; and guiding means responsive to said separating movement for causing said channel to swing with respect to said element, said guiding means having a part disposed between arms at the other end of said channel.

3. Arcing contact means, comprising: first and second conducting members cooperable to draw an arc between them upon separation thereof; one of said members comprising an elongated 6 channel of U-shaped cross section having a base forming an arc runner, a movable element disposed between arms at one end of said channel, and a connection between said element and said arms whereby said channel is swingable with respect to said element; means for causing separation of said first and second conducting mem.- bers; and guiding means responsive to said separating movement for causing said channel to swing with respect to said element, said guiding means having a slotted part disposed between arms at the other end of said channel, and a pin carried by said last named arms and disposed through said slot.

4. An electrical switch, comprising: a stationary arcing contact; a movable arcing contact c0- operating with said stationary arcing contact to draw an arc therebetween upon separation thereof, said movable arcing contact comprising a first pair of parallel spaced conducting members mounted for cooperation with said stationary Iarcing contact and a second pair of parallel spaced conducting members pivotally mounted on the contact engaging end of said first pair of conducting members for swinging movement therewith; and stationary principal'contact means engageable by said first pair of conducting members.

5. A switching device, comprising: a stationary arcing contact; a movable arcing contact cooperating with said stationary arcing contact to draw an are therebetween upon separation thereof, said movable arcing contact comprising a first pair of parallel spaced conducting members mounted for cooperation with said stationary arcing contact and a second pair of parallel spaced conducting members pivotally mounted on the contact engaging end of said first pair of conducting members for swinging movement therewith; an arc chute for receiving the arc upon separation of said arcing contacts at one end thereof and for discharging the arcing products at the other end; and guiding means responsive to separation of said arcing contacts for causing said second pair of conducting members to swing toward the discharge end of said chute causing the arc to move tow-ard the discharge end of said chute in response to arc drawing movement of said movable arcing contact.

6. A switching device, comprising: a stationary arcing contact; a movable arcing contact cooperating with said stationary arcing contact to draw an arc therebetween upon separation thereof, said movable arcing contact comprising a first pair of parallel spaced conducting members mounted for cooperation with said stationary arcing contact and a second pair of parallel spaced conducting members pivotally mounted on the contact engaging end of said first pair of conducting members for swinging movement therewith; an arc chute for receiving the arc upon separation of said arcing contacts at one end thereof and for discharging the arcing products at the other end; a stationary main contact engageable by the inside surfaces of said first pair of conducting members and comprising auxiliary contact fingers engageable with the outside surfaces of said first pair of conducting members; and guiding means responsive to separation of said arcing contacts for causing said second pair of conducting members to swing toward the discharge end of said chute causing the arc to move toward the discharge end of said chute in response to arc drawing movement of said movable arcing contact.

7. Arcing contact means, comprising: first and second conducting members cooperable to draw an arc between them upon separation thereof; an arc chute for receiving the arc drawn between said members, said chute having a discharge end; means for moving one of said members to cause separation of said first and second conducting members; an arc runner pivotally mounted on said one of said members, and guiding means for causing said arc runner to swing with respect to said one of said members toward the discharge end of said chute responsive to said separating movement, said guiding means comprising a relatively stationary part with respect to which said arc runner is movable.

HENRY V. NYE.

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

UNITED STATES PATENTS Number Name Date 1,929,049 Austin Oct, 3, 1933 1,932,061 Baker Oct. 24, 1933 1,967,623 Massey July 24, 1934 2,348,228 Scott May 9, 1944 2,363,287 Bayer Nov. 21, 1944 2,477,189 Lerstrup July 26, 1949

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