US1648684A - Electric switch - Google Patents

Description

Nov. 8, 1927.

. E E. M. HEWLETT ET AL ELECTRIC SWITCH Filed Aug. 15, 192i Inventors: Edward nHewlett, William K.Rankin,

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.Patente cl Nov. 8, 1927.

UNITED STATES PATENT- OFFICE. v

EDWARD II. HEWLETT AND WILLIAM K. RANKIN, OF SCHENECTAIDY, NEW YORK, AS- Y SIGNORS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC SWITCH.

Application filed August 15,1921. Serial No. 492,612.

This invention relates to electric switches in which the contacts are separable in an in= sulating fluid, and more particularly to those in which pressure created by the are at the opening of the switch is utilized to create a blast of oil which is directed into the path of the arc and serves to extinguish the same.

One of the objects of our invention is to provide an improved are extinguishing means of this character and according to one specific embodiment, we provide an outer vessel adapted to contain an insulating liquid and an inner pressure chamber adapted to contain and to be immersed in the insulating liquid and formed with a stationary electrode at the bottom thereof which has a passage extending therethrough, which passage communicates with the space outside of the pressure chamber. The movable electrode is positioned within thispas'sage when the switch is closed and is withdrawn therefrom through the prersure chamber on the opening of the circuit. An arc is at first formed within the pressure chamber between the stationary electrode and the movable electrode, whlch, however, is quickly transferred from the stationary electrode to an annular conducting member located within the pressure chamber and concentric with the opening in the stationary electrode. The arrangement is such that the blast of oil, which is formed as a result of the pressure created by the arc, is forced across the path of the arc stream, as it passes between the movable electrode and the annular conducting member,ina direction at approximately right angles thereto, and thence through the opening in the stationary electrode. The downward stream of oil through this opening serves to protect the contact surface ofthe stationary electrode from the hot gases. The movable electrode extends through a passage in the top. of the chamber and on the opening of the circuit is finall withdrawn from the chamber, leaving t is passage open. If, by any chance, the arc should persist until the movable electrode has been withdrawn thrOugh'thispaSSage, a second blastof oil isdirected through this passage into the arc stream. We rovide special means bywhich the gases discharged from the pressure chamber shall be freed from liquid and cooled before they are discharged into the atmosphere.

'A further object of our invention is to trode 32 when the switch is provide a switch comprising an outer oil containing vessel,'provided wlth a cover and wherein all of the switch structure with the exception of the movable electrode, which is contained withinthe vessel, is supported by and removable with the cover. This structure is entirely free from contact with the wallsof the outer vessel, which latter is referably grounded.

ther objectsand advantages will appear from the following description taken in connection with the accompanying drawing in which Fig. 1 represents in vertical section a switch embodying our invention and Fig.2 1s a fragmentary view of the lower portion of Fig. 1 drawn to a larger scale. In the drawing 10 indicates an outer metallic tank or vessel adapted to be supported on a suitable truck 11. VessellO is provided with a metallic cover 12 formed with openings in which are seated insulators 13. Extending through these insulators and serving as one of the terminals of the switch are conducting rods 14. These rods constitute a supporting means of the compression chamber or vessel 15. This chamber comprises a top (plate 16 of insulating material, such as woo a metallic bottom late 18 and a metallic cylindrical side Wal 19. The rods 14 are secured to the bottom plate 18 by means of nuts 20 which force said plate against the ends of sleeves 22 of insulating material surrounding the rods l4. The .top plate 16 surrounds the rods 14 and 'both top and bottom plates are tightly clamped against the side wall 19 by means of bolts 25, this forming a rigid structure adapted to withstand considerable internal pressure.

Secured to the lower portion of the plate 18 by means of-the bolts 26 is a conducting member 27 formed with a downwardly extending chamber or vessel 28 which is adapted to support the split contact pieces 29 of the stationary electrode cured at one end to the contact pieces 29 and at the other' to the conducting member 27 pass through suitable openings formed in the sides of 'thechamber 28 and serve as means for carrying current to the stationary electrode. Springs. 32, surrounding the 'splitcontact pieces29, are adapted the latter into contact with the movable elecin closed position. When in this position, the lower end of the vmovable electrode seats itself in' an 30. Leads 31setopress" -when the electrode 0 ening 33 in the bottom of the chamber 15.

upported upon members 27 and incontact with the side-of an opening .34 formed in the metallic plate 18 is an annular conducting member 35 formed with an arcing surface 36 arranged immediately above the contact surfaces of the pieces 29. Secured between the annular member 35 and the plate 18 is a ring-shaped insulator 37 arranged to extend some distance above the surface 36 to prevent the are from leapin to the plate 18. For this purpose also, t e plate 18 is covered with a sheet of insulation 40. A cylinder 41 com osed of insulating material surrounds the c amber 15 to prevent any electrical discharge from the chamber to the outer vessel.

The movable electrode 32 passes through insulating bushi 43 and 44 secured respectively to the p ate 16 and to the cover 12 and is arranged to be operated by any suitable mechanism not shown. Supplorted upon the plate 16 and surroundinget e movable "electrode is an insulati tu or cylinder 45 which is arranged to irect the mater al ejected upwardly through the insulator 43, has been withdrawn therefrom, against the baflle 46. Bafiie 46 is formed of insulating materia-Land 1s suprted by means of the conductin rods 14. Yiisulating sleeves 48 are interpose between the top of the bafiie and the insulator 13'and other sleeves 49. interposed between the baflie 46 and the late 16. Suitable opemngs 50 formed in t e cover 12 permit the seas formed at the opening of the switc to escape.

It a be u n t e o ning be formed tween seen from the foregoing that of the switch an arc will the movable electrode 32 and the contact pieces 29 which will be transferred to the annular conducting member 35.

The ressure created within the chamber 15 will one a blast of oil across the arc stream and through the opening formed in the'stationary electrode. Under the influence of this pressure, the oil surrounding the chamber 15 will rise within the vessel 10. The

movable electrode 32, which is rapidly withthe passage and if at that passage 7 and, attached structure are spaced drawn from the chamber 15 through the cool body of oil therein contained, finally leaves 51 formed in the insulator 43 I time the arc has not been extinguished, a second blast of-oil will be directed from the chamber up through this and into the path of the arc.

It will be noted that the vessel 10 rods 14 from the walls of the outer vessel and insulated therefrom and are readily" removable with the cover for inspection and re air.

It will be noted that int e form shown in Figs. 1 and 2 of thedrawing the arc" gases are dischar through the bottom opening andthroug the openings formed in the sides of the chamber 28. In certain cases to prevent injury to the contacts 29 it may be advisable to close the lower portion of the chamber 28 and to provide the opening therefrom at a point between contacts 29 and the liquid, an 1111161 vessel ada ted-to contain and to be immersed in said liquid, a stationary electrode within said inner vessel, a

movable electrode extending through said cover and separable from said stationary electrode to form an arc in said inner vessel andmeans for conducting current to said stationary electrode, said means passing through said cover and servin as a support for said inner vessel an stationary electrode.

having a, cover and adapted to contain an insulatmg liquid, an inner vessel constructed to withstand-internal pressure and adapted to be immersed in and to contain said liquid, a stationary electrode, a movable electrode separable from .said stationary electrode to form an arc within said inner vessel, and means comprising va plurality of similar members extending through and insulated Y from said cover for supporting said inner vessel and stationary electrode free and insulated from the walls of said outer vessel.

3. In a switch, an outer vessel having a cpver and adapted to contain an insulating hquid, an inner vessel constructed to withstand internal pressure and ada ted to be immersed in and to contain sai liquid, a stationary electrode, a movable electrode extending upwardly through said vessels and 2. Ina switch, an outer metallic vessel insulated therefrom, said movable electrode .being" se arable from said stationary elec strode tov orm an are within said inner vessel, and means comprising a lurality of insulator bushings and conducting rods extending therethrough for su porting said inner vessel and station-, ary e ectrode free and insulated fromfthe walls of said outer vessel.

extending t oughsaid cover Ill . 4. In a man, an outer manic vessel adapted to contain an insulating liquid, a

vessel cover for said outer. vessel, an inner spaced from said cover and forming a'compressiqn chamber, said inner vessel adapted to contain .and to be immersed in said in'sulatingliquid, a stationary electrode electrically can to said movable electrode insulated from said we "eels. and separable from said stationary electrode to form an arc within'said inner vessel, and conducting supports for said inner vessel and stationary electrode extending through and insulated from said cover.

5.'In a switch, an outer'metallic' vessel inner vessel, a

. cover for said outer vessel, an inner vessel formed in part of conducting material and constructed to withstand internal pressure, said, inner vessel being adapted to contain and to be immersed in said insulating liquid, a stationary electrode electrically connected to the conducting portion of said inner vessel, a movable electrode insulated from said vessels, and separable from said stationary electrode to form an are within said inner vessel, insulator bushings mounted in said cover, and conducting rods extending through said bushings and in electrical connection with the conducting portion of said inner vessel, said rods supporting said inner vessel and stationary electrode free of and insulated from said outer vessel, and said inner vessel and stationary electrode being removable with said cover.

6. In a switch, a vessel adapted to contain an insulating liquid, electrodes separable to form an are within said vessel, one of said electrodes bein supported by an end Wall of said vessel and being formed with an opening therethrough for receiving the other electrode to make contact therewith, said end wall having a passage therein communicating with the outer end of said opening in the electrode, through which passage insulating liquid is discharged from said openmg. n

7. In a switch, a vessel adapted to contain an insulating liquid, electrodes separable to form an are within said vessel, one of said electrodes being supported by an end wall of said Vessel and being formed with an opening therethrough to receive the other electrode to make contact therewith, said end wall comprising an electrode retaining member provided with a passage therein communicating with the outer end of said open ing in the electrode, through which passa e insulating liquid is discharged from sald opening. w

8. In a switch, an outer vessel adapted to contain an insulating fluid, a closed inner vessel adapted to be submerged in and to contain .said insulating fluid, a stationary electrode within and supported by said inner vessel, a-movable electrode adapted to cooperate therewith and to be Withdrawn through the top of said inner vessel, a cover for said outer vessel and means depending from said cover for supporting said inner vessel.

9. In a switch, a vessel adapted to contain an insulating liquid, an electrode within said" vessel, a second electrode within said vessel I and separable from said first named electrode, and a. conducting member in proximity to said first named electrode but separated therefrom by a space which communicates with the exterior of said vessel,

the arrangement being such that upon separation of the electrodes an arc is formed within said vessel, which are is transferred from said first named electrode to said conductin member, and insulating fluid under the inifuence of pressure created by said are is forced. into the path of said are and through said space.

10. An electric switch comprising a vessel adapted -to contain an insulating fluid, a

cover therefor, an inner vessel adapted to be submerged in said insulating fluid, a stationary electrode carried at the bottom of said inner vessel, a movable electrode adapted to cooperate therewith to form an arc in said inner vessel and to be withdrawn through the top thereof, a bafile interposed in the path of the material ejected by said are when said movable electrode is Withdrawn and means for removably supporting said inner vessel, said stationary electrode and said baflie from said cover.

In witness whereof, we have hereunto set our hands this 12th day of August, 1921. EDWARD M. HEWLETT. WILLIAM K. RANKIN.

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