US3010002A - Electrical switch - Google Patents

Description

E. LANGE ELECTRICAL SWITCH Filed Jan. 6, 1960 J y ww. @n

Nov. 21, 1961 United States Patent() way Filed Jan. 6, 1960, Ser. No. 902 7 Claims. (Cl. 200--148) This invention relates to an electrical switch of the kind in which arcs are quenched by currents of quenching medium under pressure produced by the arcs themselves, comprising `a hollow body divided into chambers.

According to the invention a switch of the kind referred to is characterised in that in parallel to current interruption means situated in one of the chambers there is arranged in another chamber a plurality of spaced quenching terminals connected to guide conductors which extend into the vicinity of a movable part of said current interruption means, so that an arc drawn bythe said movable part is divided up and conducted to the quenching terminals to form secondary arcs which arequenched by the outowing pressure quenching medium. n

Further and optional features of the invention appear from the following description and claims.

Two switches according to the invention are illustrated by way of example in sectional elevation in the accompanying drawings, in which- FIGURE l illustrates a switch with a single switch pin, and FIGURE 2 shows a switch with two switch pins which move in opposite directions.

The switch shown in FIGURE l comprises a hollow body 1, divided by an apertured wall 9 into two chambers 2 and 3. In the chamber 2is a movablefswitch pin 4 which in the closed position shown constitutes an electrical connection between two terminals 5 and 6.

The terminals 5 and 6 have inclined portions which serve as guide conductors for the arc, and terminate in apertured conductors 7 and 8 which form passages to outflow openings 28 and 29 of the chamber 3.` The chambers 2 and 3 are filled with air or other quenching medium, and the openings 28 and 29 may be provided 12, 13 and 14, 15 and the quenching terminals 16, 17

and 18, 19.

The guide conductors 12, 13,14, and 15 terminate in the chamber 2 in the vicinity of -the movable switch pin 4 and are situated in the apertures 21, 22, 23 and 24.y

Guide portions of the terminals 5 and 6 lie inthe apertures 20 and 25.

The inserts 26 and 27 are formed as convergent-di vergent nozzles in which the arcs are effectively exposed to the flow of quenching medium.

The quenchingmedium escapes to atmosphere through the outflow openings 28 and 29. p

The arrangement of FIGURE l works as follows:

On opening of the switch the switch pin 4 is moved downwards and an arc burns between the terminal 5 and the switch pin 4.

The root of the arc on the terminal 5 shifts immediately along the guide portion to the conductor 7. When the switch pin tip comes to the level of the guide con ductor 12, the arc jumps over on to the lat-ter and strikes between the terminal 16 and the conductor 7, since here the distance is much shorter than between the switch pin 4 andthe terminal 5.

The arc in the chamber 2 is thus shunted or by-passed over the length between the parts 12 and 5, and burns in ice the chamber 3 between the terminal 16 and the apertured conductor 7.

In the chamber 2 thev arc burns only between the switch pin 4 and the guide conductor 12. n On further movement of the switch pin 4 its tip comes into the vicinity of the guide conductor 13, so that the arc burning on the guide conductor 12 jumps over with its root on to the guide conductor 13 and thence the arc is drawn by further movement of the switch pin 4 along in the chamber 2, until the tip of the switch pin 4 comes into the vicinity of guide conductor 14, where then the arc, seeking the shorter distance, burns between the quenching terminals 17 and 18. This strike-over between the terminals 17 and 18 can be assisted if one or more further openings or a slot is or are provided in the wall 9, permitting the arc to jump overbetween the terminals 17 and 18 before the tip of the switch pin 4 has reached the guide conductor 14.

Due to the arcs in the chambers 2 and 3 a great pressure increase is produced in the quenching medium which ensures that `the arcs burning in the chamber 3 are exposed to effective blasts of quenching medium so that quenching of the arcs can occur even before the top of the switch pin 4 has reached the terminal 6.

On further movement of the switch pin 4 its tip comes into the vicinity of the guide conductor 15, so that the arc burning between the pin 4 and the guide conductor .14 is bridged over and quenchedy and the arc is ynow guided by the guide conductor 15 from the switch pin 4 to the terminal 19 and strikes between the terminal 19 and the apertured conductor 8.v

Now arcs may be burning between the parts 7 and 16, between the terminals 17 and 18, and between the parts 19 and 18. By the pressure rise produced in the chambers 2 and 3 the arcs are exposed to four effective blasts of pressure medium, and very reliable quenching of the arcs is etected.

In the described arrangement it is particularly advantageous that, due to the initial burning of the arc in the chamber 2 and the pressure rise thereby produced, the chamber 2 serves for the temporary storage of medium under pressure and also the tlow of the quenching rnedium through the apertures 20 to 25 in the wall 9 towards the chamber 3 urges the arc roots towards the conductors situated in the chamber 3.

Furthermore, by the described arrangement, `the object -is achieved that by the division ofthe hollow body 1 into two chambers, one chamber is used only for the initial drawing and limiting of the arc, While the other chamber serves only for the quenching of the short secondary arcs. There is no direct electrical connection between the currentinterruption point at the separation of the pin 4 from the terminal 5 and the quenching gap arranged in parallel in the quenching chamber 3, but the controlling of the are or arcs is effected only by striking over on to the conductors and terminals situated -at xed distances from one another.

Normally the current flows through the pin 4 while the switch is closed and the quenching or spark gap in the chamber 3 is in parallel therewith but carries no current.

In the quenching chamber 3 in FIGURE 2 the arrangement of conductors and terminals is similar to that in FIGURE l, like reference numerals indicating like parts. In FIGURE 2 two switch pins 45 and 46 are provided in the chamberZ and move in opposite directions to one another. p

The current is supplied to the movable switch pins 45 and 46, which are electrically connected to one another through ya tixed contact 38, through the terminals 5 and 6.

The fixed contact 38 lis secured to the insert 32 and is 3 prolonged towards the passage 33 by guide conductors 43 and 44.

The arrangement shown in FIGURE 2 works as follows:

On opening of the switch the switch pins 45 and 46 are moved in opposite directions away from one another and arcs are drawn between the xed contact 38 and the tips of the movable switch pins 4S `and 46.

Through the guide conductors 43, 44 the roots of the arcs burning on the fixed contact 38 are immediately conducted towards the passage 33, and when the tips of the switch pins 4S and 46 come into the vicinity of the guide conductors 13 and 14 the two arcs jump so that one arc burns between guide conductor 43 and quenching terminal 17 and the other arc burns betweenv guide conductor 44 and quenching terminal 18, and in the chamber 2 arcs now burn only between the switch pin 45 and the guide conductor 13 and between the -switch pin 46 and the guide conductor 14.

The subsequent bridging-over of the arcs in the chamber 2 for the strike-over of three arcs between the quenching terminals 16 to 19 and the apertured conductors '7 and 8 in the chamber 3 follows as described above with refer,- ence to FIGURE 1, so that when the tips of the switch pins have arrived in the terminals and 6, arcs burn only in the chamber 3.'

Due to the pressure rises produced in the chambers 2 and 3 and due to the four effective zones of action of the quenching medium on the three secondary arcs an easy and reliable quenching of the arcs is eiected.

By the use of two switch pins a more rapid quenching operation is rendered possible, and the quenching of the arcs may be completed before the tips of the switch pins reach the terminals 5 and 6.

Gas or liquid with or without inert powder can be used as a quenching medium.

I claim:

1. An electrical switch of the kind in which arcs are quenched by the action of quenching medium ilowing under pressure produced by said arcs, comprising in cox bination a hollow body, an apertured wall dividing said hollow body into a iirst chamber and a second chamber which has outlets at its ends, two terminals arranged one at each; end of said irst chamber, at. least one movable switch pin accommodated adjacent to said apertu-red wall in said first chamber and forming an electrical connection between said terminals in the closed condition of the switch and being guided so that it can move only axially to effect opening `and closing of the switch, two end conductors arranged one at each end of said second chamber, two guide portions eachelectrically connecting one each of said end conductors to one each of said terminals, said guide portions extending through apertures in said wall, yat least one intermediate conductor in said second charnber, and two guide conductors extending from each said intermediate conductor towards said rst chamber, each of said guide conductors being arranged in an aperture in said wall, the arrangement being such that when in the operation of opening the switch each said switch pin is moved axially its tip travels past-a plurality of said guide conductors in sequence and draws arcs in sequence in said first chamber and the roots of the arcs travel through said apertures in-said-wall on said guide portions and said guide conductors so that the arcs die in said rst chamber and burn in said second chamber between said intermediate and end conductors and are subjected to the action of quenching medium owng in said second chamber towards said outlets.

2. A switch as claimed in. claim 1 comprising also a quenching terminal at each end of each said intermediate conductor.

3. A switch -as claimed' in claim 1, comprising also at least one nozzle insert in said second chamber. q

4. A switch as claimed in claim l, each said intermediate conductorv being tubular.

5. A switch as claimed in claim l, each said end conductor having an aperture leading from said second chamber to one of said outlets.

6. A switch as claimed in claim l, comprising also a `quenching terminal at eac-h end of each said intermediate conductor and at least one nozzle insert in said second chamber, each said intermediate conductor being tubular and each said eno conductor having an aperture leading from said second chamber to one of said outlets, there being a passage for quenching medium extending between said outlets and passing. through said end conductors and Vthrough each said nozzle insert and through each said References Cited in the le of this patent UNITED STATES PATENTS 2,151,551 Ishiwata Mar. 21, 1939 2,714,645 Salzer n Aug. 2, 1955 2,908,789 i Lange Oct, 13, 1959

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