US1548799A - Electric switch - Google Patents

Description

Aug. 4, 1925. 1,548,799

' J. D. HILLIARD ELECTRIC SWITCH Filed Aug. l0. 1921 2 Sheets-Sheet 1 Fig. 1. vm.'

Lm EL $9 m Inventor:

. John, D. Hilliard,

His Httorneg.

Ang. 4, 1925. 1,548,799

J. D. HILLIARD ELECTRIC SWITCH Filed Aug. 1o, 1921 2 Shaver-sneu a 123.2. Fig.

ITM/entorf John D. HH liar-d,

W Ma/WW' His )qttovneg 1 the breaks.

Patented Aug. 4, 1925.

UNITED STATES l 1,548,799 PATENT QFFICE.

JOHN D. HILLIARD, F SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC 'swmcl f Appiication mea Angustia, 1921. serial 151. 491,127.

To aZZ'fwzom z't may concer/n.:

Be it known that I, J orrN D. HILLIARD, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Electric Switches, of which' the following is a specification. i

My invention'relates to electric switches and particularly to those in which the con-I tacts are separable in an insulating fluid. In switches of this type heretofore employed use has been made of means whereby the pressure produced by the arc at the opening of the switch is utilized to create a blast of oilwhich is directed into the path of the arc and serves to extinguish the same. According to my present invention I seek to improve the circuit vinterrupting capacity of .switches of this character by providing a plurality of breaks so arranged that the pressure produced by the arc 'at one of the breaks serves to force oil or other insulating fluid into the path of the arc at another of This oil not only serves to cool the gases of the second arc and so aid in extinguishing the same but also replaces thev arc gases by a body of oil* Which, interposed in the circuit, offers an extremely high resistance to the further passage of current. By having the arc which it is intended to use as a source of pressure form ata point somewhat distant from the second arc, the hot gases of the former may be kept, away from the latter and thus there is no tendency for thesel gases to lower the dielectric strength of the medium .surrounding the second break or tomaintain the gases of the second arc at a high temperature.

In the preferred embodiment of my invention I draw the arc which is to be subjected to the stream or blast of oil through a narrow passage which not only limits the quantity of gas formed but also by restricting the area of the arc 'stream increases its resistance;`

Othen advantages and objects of the invention will appear from the following description taken in' connection with the accompanying drawing wherein Fig.I 1 shows a switch partly in section embodying my invention; and Figs. 2 and 3 are' views partly in section of a portion of the switch similar to that shown in Fig. 1 but embodying a modifiedl form of my invention. v

InFig. 1 I have shown a switch comprisinga metallic vessel 10 adapted to contain an insulating flui-d such as oil. Extending into the tank or vessel 10 are bushings 11 provided with suitable terminals 12 to which the circuit to be controlled is connected. Supported upon each bushing and depending therefrom below the normal surface of the insulating fluid is a vessel or chamber 13. These chambers are so' constructed as `'to withstand the considerable 'internal pressure and are well insulated by means of the bushings 11 from the vessel 10. vAt one end of` each chamber is mounted a fixed contact 14 and movable into and out of the other end of each chamber is a movable contact 15 which as shown consists of a rod carried at an end of and movable with a bridging member 17 vwhich latter is supported and movable by means of a rod 18 to which any suitable operating fmechanism, not shown,

may be attached. Contact rod 15 moves` ing bushing 20. 'Mountedl upon the bushing 420-bv means of rods 21 are insulated plates 22 which are spaced apart and are provided at their centers with alined openings 23 through which the rod 15 is adapted to pass. Rod 15 is designed to cooperate with a con tact 2/1 formed at the lower end of the conducting member 25. This member is mounted to move in an insulating bushing 26 which is `supported by means of a perforated plate 27. Seated in a recess 28 in the insulating bushing 26 is a compression spring 29 which bears at its lower end against the member 25. The upper end of the member 25 is formed with a contact 25 adapted to c0- operate with a contact 14 at the lower end of the terminal 12. ,I In practice when the switch is opened the first break occurs at the contacts 14 and 25', the spring 29 serving to maintain the member 25 in contact with the rod 15 during the downward movement of the latter until the lower face of the contact 24 strikes the u per plate 22. 'During this initial part of t e operation an arc is drawn between the contacts 14 and 25 which by dissociation and vaporization of the oil creates a high preswithdrawal of the rod through the open ing 19 results in the formation of a second arc between the rod and Contact 24. Oil under the influence of the pressure created by the first formed arc in seeking an exit from the chamber 13 flows between the plates 22 and around the rod 15 as it recedes through the opening 19. It will be thus seen that a body of cool oil unmixed with gases is proiected into the path of the lower are with the result that the same is quickly extinguished.

If desired, there may be substituted for the rod 15 a tube open at its upper end and at some point near its attachment to the bridging member 17. It is preferable in this case that the tube be constructed to it rather closely in the bushing 2() so that the oil which is ejected from the chamber 13 will be forced to pass down the center of the tube.

I provide a small opening through the wall of the pressure chamber to permit the slow escape of gases which collect at the top of the chamber.

In the form of invention shown in Fig. 2 the rod 15 extends through the length of the compression chamber and cooperates at its upper end with the contact 14. In place of the insulating bushing 26 of Fig. 1 I provide a conducting member 31 through Y which the rod 15 moves and which is supported by means of the perforated insulating plate 33. A contact '34 at'the lower end of the member 31 serves to insure electrical connection between the rod 15 and member 31 while the rod is within the member and serves as an arcing electrode after the rod in its downward movement has left the member 31. The passage 37 in the member 31 through which the rod 15 operates is formed with an enlargement at 35 to containY a ball 36 which is adapted to close the passage upon the withdrawal of the rod.

In the ,operation of the form of my in- '.vention shown in Fig. 2 the initial or pressure producing arc is formed between the contact 14 and rod 15. As the upper end of this rod is drawn below the upper end of member 31 this arc is transferred from the rod to the conducting member 31. A further lowering of the rod 15 permits the ball 36 to seat itself centrally of the passage 37 and prevent any gases being forced -downwardly through the member 31. In the final movement of the rod 15 its upper end leaves the contact 34 and forms a second arc which is drawn downwardly through a restricted passage 38 in the bushing 39. Oil under the pressure created byy the upper arc is forced through the restricted passage 38 and serves to extinguish the lower arc and consequently break the circuit. In the upper part of the pressure chamber I preferably provide a hood 40 which serves to retain a portion of the gases formed within the chamber. This acts as a cushion and prevents toosuddenl a rise of pressure within the chamber and a consequent shock to the apparatus. 'If desired, I may dispense with the ball 36 in which case the passage 37 will be'formed without the enlargement 35.

The form ofmy invention shown in Fig. 3 is similar to that of Fig. 1 in that use is made of an intermediate conducting member 25 which is adapted to form contact at its upper end with the stationary electrode 14 and at its lower end with the movable conducting rod 15 and is springpressed away from the electrode 14. In the form shown in Fig. 3, however, the lower portion of the intermediate conducting member-25 moves freely in a recess 44 formed in -a specially constructed insulat ing member or bushing 42 which latter is supported from the bottom of the pressure chamber 43. Connecting with-the bottom of the recess 44 is an opening 45 through which the rod 15 moves and arranged at ri ghi'. angles to the opening 45 and crossing the saine are a plurality of passages 46 each of which communicates at one end with a longitudinal passage 47 and at the other end with the interior of the vessel 10'a't a point outside of the chamber 43. The passage 47 communicates at its upper end with the interior of the chamber 43, In the closed position of the switch the presence of the rod 1,5 in the opening 14 serves to cut olf communication through the passages 46. The chamber 43 is provided with a gas-collecting hood 40 similar to that shown in Fig. 2.

In operation the initial arc is drawn between the contact 14 and conducting member 25 which causes a very high pressure to be developed within the chamber 43. When the lower end of the member 25 reaches the bottom of the recess 44 it is stopped by the insulator 42 and the further downward movement of the rod 15 results in the drawing of the second arc through the opening 45, passages 46 are opened in succession and oil under the iniiuence of the pressure within the chamber 43 is projected with great force across the arc in a direction at right angles thereto and extinguishes the same. 1

lVhat I claim as new and desire to secure by Letters Patent of the United States is:

1. In a switch, a tank adapted to contain an insulating fluid, a vessel therein, cooperating contacts arranged to form two arcs in series in said vessel, and means whereby the fiuid under the pressure created by one of said arcs is directed intosthe path of the other arc. y

'2. In a switch, a tank adapted to contain CII mesme an insulating'iluid, a pressure resisting vessel within said tank, a plurality of sets of relatively movable contacts in said vessel cqnnected in series and adapted when separated to draw arcs in said fluid, and means for directing fluid expelled by one ofv said arcs into the path of another of said arcs.

3. In a switch, a tank adapted-to contain an insulating liquid, a pressure resisting vessel in said tank, a single contact operating member extending into said vessel, two pairs of contacts separable within said insulating liquid to draw arcs in succession, and means whereby a portion of saidrliquid under influence of the pressure created by the first drawn arc, is forced into the path of the second drawn arc. p

4. In a switch comprising a vessel containing a body of insulating liquid, means for forming an arc in said insulating liquid, means forming a restricted passage in said liquid, means for forming a second arc in said restricted passage and means whereby pressure created by said first formed arc will force liquid from said body of insulating liquid through said restricted passage in the path of said second arc.

5. In a switch, an outer vessel adapted to contain an insulating liquid, an inner vessel adapted to be immersed in said insulating liquid and to contain insulating liquid, means for forming two arcs in succession within said innervessel and means whereby pressure created by first formed arc, .forces insulating liquid into the path of said second formed arc and out of said inner vessel.

6. In a switch, an outer vessel adapted to contain an insulating liquid, an innervessel adapt-ed to be immersed in said insulating liquid and'to contain insulating liquid, said inner vessel having a restricted passage through the wall thereof', means for forming an arc Within the inner Vessel, means for subsequently :forming a second arc within said passage, and means whereby pressure created by the first formed arc forces insulating liquid through said assage. y

7. In a switch, a vessel a apted to contain ,insulating fluid, a. stationary electrode within the said vessel, a movable-electrode, an intermediate conducting member within said vessel adapted to form an arc within said fluid with each of said electrodes and means whereby insulating fluid under he influence of pressure created by one of said arcs is forced into the path of the other of said arcs.

8. In a switch, a vessel adapted to contain insulating fluid, and formed with a restricted passage, a stationary electrode within said vessel, a movable electrode, an intermediate conducting member within said vessel adapted yto form an arc within said fluid wit-heach of said electrodes, one of said arcs being formed in said restricted passage, and

means whereby insulating fluid under pressure created by the other of said arcs is forcedV through said restricted passage.

9. In a switch, an outer vessel, an inner vessel adapted to contain and to be im.- mersed in insulating liquid contained within said outer vessel, a stationary electrode within said inner vessel, E1n electrode movable into and out of said inner vessel, an intermediate conducting member biased away from said stationary and towaid said ii'iovable electrode whereby upon movement -ot' said movable electrode away from said stationary electrode, an arc is drawn between s`aid stationary electrode and conducting member, and means for limiting the y movement of said conducting member away from said stationary electrode, whereby y upon further movement of said movable electrode away from said Vstationary electrode, an arc is dra-wn between said conducting member and movable 'electrode and means whereby pressure created by said first foi-ined are forces insulating liquid into the' 'path ot' said second formed arc.

10. In a switch, a vessel adapted to contain an insulating fluid, a stationary electrode within said vessel, a movable electrode adapted to make contact with the said stationary electrode, a conducting memberv sur-y rounding said movable electrode and so arranged that upon withdrawal of said inevable electrode away from said stationary electrode, an arc is first` formed between said stationary and movable electrodes which is subsequently transferred from said movable electrode to said conducting' meinbei and finally a. second arcis drawn between said movable electrode and conducting member and means whereby liquid under the influence of pressure created by of said second formed arc.

. Y 11. In a switch, a vesseladapted to contain an insulating fluid and formed withA a restricted passage, a stationary electrode within said vessel, a movable electrode adapted to make contact with said stationary elcctrode, a conducting member surrounding said movable electrode and so arranged that upon withdrawal 'of said movable electrode away from said ystationary electrode an arc is first 'formed between said stationary and movable electrodes which arc is subsequently transferred from said movable electrode .to said conducting member and finally a second arc is drawn within said yrestricted passage and meanswhereby insu-

Images