Патент USA US2406469код для вставки
Aug. 27, 1946. 1.. R. LUDWIG ET AL 2,406,469 C IRCUIT INTERRUPTER Filed Nov. 11, 1942 /62 /60 .h E M6 9% $ . v ‘INVENTORS L eon A’. Ludwll'g, Mnfhrap M. lead: & BenjamMRBa/rér zamamz 6‘ - ATTOR ‘ Patented Aug. 27, 1946 2,406,469 UNITED STATES PATENT OFFICE 2,406,469 CIRCUIT INTERRUPTER Leon R. Ludwig and Winthrop M. Leeds, Wil kinsburg, and Benjamin P. Baker, Turtle Creek, Pa., assignors to Westinghouse Electric Corpo ration, East Pittsburgh, Pa., a corporation of Pennsylvania Application November 11, 1942, Serial No. 465,244 2 Claims. (Cl. 200-150) This invention relates to circuit interrupters, and, more particularly, to are extinguishing structures therefor. Certain features of the in vention are described and claimed in applicants’ divisional application, ?led December" 22, 1945, Serial No. 636,940, entitled, “Circuit interrupt ers,” and assigned to the assignee of the instant application. 2 of ?ow of the inwardly flowing streams is changed to a direction which is longitudinal of the arc, and‘a plurality of venting passages are provided for the rapid venting of contaminated ?uid. Another object is to provide an improved structure of the type described in the immedi ately preceding paragraph in which piston means are disposed between the two arcs to prevent Other features are described and broadly contaminated ?uid from the pressure-generating claimed in a divisional case, ?led December 22, 10 are coming in contact with the interrupting 1945, Serial No. 636,941, entitled “Circuit inter arc. rupters,” and assigned to the assignee of the Another object is to provide an improved cir instant application. cuit interrupter wherein fluid adjacent to a More speci?cally our invention relates to a pressure-generating arc is forced under pressure novel structure for effecting the very rapid ex 15 toward the interrupting arc and to dispose pis tinction of electric arcs drawn in circuit inter ton means between the two arcs, which piston rupters. It is particularly applicable to the inter means can be by-passed near the end of its ruption of high voltage arcs, such as those drawn travel. in a 287 kv. circuit, and will effect their inter Further objects and advantages will readily ruption in less than one cycle. Our invention 20 become apparent upon a reading of the follow is, however, not limited in its application only ing description taken in conjunction with the to high voltage circuits. It is also applicable on drawing, in which: low voltage circuits, but merely for purposes of illustration it is described in the speci?cation in a preferred embodiment as used on a high 25 voltage circuit. Extensive experimental investigation has clear Fig. 1 is a side elevational view in cross section of a circuit interrupter embodying our inven tion; Fig. 2 is a side elevational view in cross sec tion taken on the line II—II of Fig. 1; and Fig. 3 is a sectional view taken on the line III-III of Fig. 1. such as oil, occurs after it impinges upon the Referring to the drawing and in particular to arc stream. It is therefore desirable to elimi Fig. l, the reference numeral I designates gen nate such contaminated ?uid as quickly as pos erally an arc extinguishing unit suspended from sible, and to subject the arc stream to the action one line terminal of the circuit interrupter in of fresh ?uid of high dielectric strength. It is a suitable tank, not shown, and submerged in one of the objects of our invention to provide 35 a suitable arc extinguishing ?uid, such as oil. an arc extinguishing structure which makes full A conducting bridging bar I49 serves to connect use of this fact. electrically the arc extinguishing unit I with an Another object of our invention is to provide identical unit, not shown, in a manner well improved piston means associated with the mov known in the art. ing contact structure to effect the rapid extinc 40 We have found it desirable to rapidly vent tion of low current arcs. ionized products of decomposition resulting from Another object is to provide an improved arc an arc extinguishing ?uid impinging upon the ly demonstrated that a rapid lowering of the dielectric strength of an arc extinguishing ?uid, extinguishing structure which directs a plurality of radially inwardly ?owing streams of ?uid arc stream. a pressure-generating arc and an interrupting arc, the pressure-generating are causing a plu along the length of the arc stream rather than After an arc extinguishing ?uid against the are, changes the direction of flow 45 strikes the arc stream, performing its de-ioniz ing function by turbulently breaking up and cool to one which is longitudinal of the arc, and ing the ionized arc path, contamination of the then provides a plurality of radially out?owing ?uid decreases its usefulness for further extin discharge streams which are substantially per guishing and. insulating purposes. We have, pendicular to the arc. therefore, found it desirable to subject the arc Another object is to provide an improved arc stream to a plurality of radially in?owing streams extinguishing structure which will, produce both to use a single stream to de-ionize a consider able length of arc. At a number of intermedi Preferably the direction 55 ate points along the arc stream, we provide a rality of inwardly ?owing streams to converge on the interrupting arc. of arc extinguishing ?uid at a number of points 2,406,469 4 3 plurality of vents to allow the contaminated fluid to be rapidly vented radially outward from the arc space. Preferably the inflowing ?uid which strikes the arc stream should strike the arc radially thereof from at least opposite sides to maintain the arc stream in a central position away from adja cently disposed insulating surfaces. If an arc contacts an insulating surface it tends not only to burn away the insulating surface but also to leave carbon thereon which has conducting properties. In the construction of our invention we preferably maintain the are ‘away from ~adja~ cently disposed insulating walls by subjecting at least opposite sides of the arc stream to a radially inward flow of ?uid. In this embodiment of our invention, a plu rality of insulating plates are pressed togther to form an insulating arcing structure having en trance and vent passages more fully described hereinafter, Tie rods 62 hold the insulating plates rigidly in position. A resiliently mounted relatively stationary contact I42 is provided which cooperates with an intermediate contact member I43 to draw a pressure generating arc I44, ‘as more clearly shown in Fig. 2. The in termediate contact I43 has secured thereto at its lower end a metallic spider member I45 which serves as a lower seat for a battery of compres sion springs I46. Cooperating with the inter mediate contact I43 to draw an interrupting arc I48 (see Fig. 2) is a lower movable contact I41. A conducting bridging member I49 operates the lower movable contact I41. Suitable operating mechanism, not shown, actuates the conducting bridging member I49. A ?exible conductor I56 electrically connects the stationary contact I42 follows the initial movement of the intermediate contact I43 until the shoulder I58 on the sta tionary contact I42 strikes the insulating plate I59. Further downward movement of the lower movable contact I41 draws substantially simul taneously both a pressure-generating arc I44 and an interrupting arc I48, as more clearly shown in Fig.2. It would, of course, be possible to have the two arcs formed sequentially by raising the position of the insulating plate I59. In this event the pressure-generatingarc I44 would be formed ?rst, and the resulting pressure would help to drive the piston I55 downward. During the interruption of low currents, the pressure generated by the pressure-generating arc I44 will be relatively low and reliance for the fluid motion is placed on the compression springs I46. The downward movement of the piston I155 causes oil to ‘flow as indicated by the arrows I66 in Fig. 1. The fluid ?ows downwardly as caused ‘by the piston I55 through two kidney~ shaped vertical flow passages generally desig nated by the reference numerals 2 provided in the plurality of contiguously disposed insulating plates, as shown more clearly in Fig. 3. After passing downwardly through the two vertically disposed ?ow passages 2, the fluid passes radi ally inwardly toward the interrupting arc 148 through a plurality, in this, instance four, inlet passages 3 provided by a pair of insulating inlet plates 4 having a con?guration more clearly shown in Fig. 3. The ?uid after contacting the interrupting arc I48 passes upwardly and down wardly through adjacently disposed ori?ce plates I152. 5 and out of the arc-extinguishing unit I through vent passages I61 disposed substantially at right angles to the direction of the inlet passages 3. The vent passages I61 are formed by insulating vent plates 1, which also provide an insulating It will be apparent that in the closed-circuit po~ sition of the interrupter shown in Fig. 1, the elec trical circuit therethrough comprises the contact foot I52, the top metallic plate I5I, ?exible con the orifice provided by the insulating ori?ce plates 5. Thus, the ori?ces 8 provided by the insulating orifice plates 5 and the insulating vent with a top metallic plate I51 which, in this in stance, is an integral portion of the contact foot ori?ce 8 of substantially the same diameter as ductor I50, relatively stationary contact I42, in 45 plates 1 cause the arc-extinguishing ?uid to ?ow longitudinally of the interrupting arc I48 inti termediate contact I43, lower movable contact I41 mately contacting therewith before this arc-‘ex and conducting bridging member I49, from tinguishing ?uid is vented out of the arc-extin whence the circuit passes through another iden guishing unit I through the oppositely disposed tical arc extinguishing unit, not shown, to the venting passages I61 as provided by the vent other terminal of the interrupter. plates 1. Rigidly secured by contact button I53 to the Certain features of the ?ow passage arrange intermediate contact I43 is a metallic valve plate I54. A perforated metallic piston I55 has a lim ment are described and broadly claimed in U. ‘S. ited permissible sliding movement with respect patent application, Serial No. 574,856, ?led Jan to'the intermediate contact I43 as determined by 55 uary 27, 1945, ‘by Winthrop M. Leeds and Benja the metallic valve plate I54 and integrally formed min P. Baker, and assigned to the assignee of the shoulders I56 formed on the intermediate ‘con instant invention. During the interruption of high short~circuit tact I43. When the interrupter is in the closed-circuit currents, the pressure generated by the pressure-. position, as is shown in Fig, 1, the battery of com 60 generating arc I44 will assist the compression springs I46 in moving the piston I55 downwardly pression springs I46 is compressed, metallic pis ton I55 rests upon the shoulder I56 and the to cause an increased fluid flow toward the in terrupting arc I48. valve I51 is opened. When it is desired to open the electrical circuit through the interrupter, It will be observed that when the perforated suitable operating mechanism, not shown, moves metallic piston I55 strikes the insulating plate I6 I, the conducting bridging bar I49 downward. The as shown by the dotted lines in Fig. 1, ?uid from intermediate contact I43 being strongly biased the pressure-generating arc I44 may continue to downward by the compression springs I46 rapidly flow past the perforated plate I55 in the annular follows the initial downward movement of the space indicated by the reference numeral I62. lower movable contact I41 to result in the me 70 On the interruption of high currents, this by tallic valve plate I54 closing the apertures in the passing action is of advantage for arc interrup perforated piston I55, the piston I55 remaining tion which possibly may not have occurred by practically stationary during this time because of the time the perforated plate I55 has come to rest, and further fluid motion caused by the pres the dashpot action. During the initial movement, the resiliently mounted stationary contact I42 75 sure generating arc I44 is therefore desirable. 5 2,408,469 It will be observed that in this embodiment of our invention, we have provided annular pockets I65 disposed between the inlet passages and the vent passages. The annular pockets “55 provide parting from the spirit and scope of the appended claims. We claim as our invention: 1. In a circuit interrupter, a relatively station ary contact, an intermediate contact, a moving a readily available quantity of oil adjacent the arc path, and also the annular pockets I65 break up the insulaitng surfaces adjacent to the are I 43 to minimize the possibility of carbonization of contact, the intermediate contact being coop erable with the stationary contact to produce a these insulating surfaces. tact being cooperable with the moving contact We have provided a plurality, in this instance two, additional annular oil-retaining pockets I65 at the lower end of the structure between the low er venting passages IE1 and the bottom insu lating plate I58. It is desirable to maintain an increased pressure within the arcing region, for the dielectric strength of an arc extinguishing ?uid depends not only on the degree of ionization therein but also on the pressure, increased pres sure causing increased dielectric strength. We have found that the provision of the oil-retaining pockets IE6 reduces the gas and ?uid leakage by making the how more turbulent as the lower mov able contact MT is Withdrawn out of the are ex tinguishing structure. The concept of securing a piston to an inter mediate contact disposed in an arc extinguishing unit of the type which produces both a pressure generating arc and an interrupting arc is de scribed and broadly claimed in an application pressure-generating arc, the intermediate con to draw an interrupting arc, passage means ex tending between the pressure generating arc and the interrupting arc, a piston operatively con nected to the intermediate contact and movable‘ therewith, the piston making a comparatively tight ?t With the walls of the passage means dur ing the initial movement thereof, an enlarged portion in the passage means operative after the piston has neared the end of its travel to permit a by-passing of ?uid past the piston, the ?uid pressure created by the pressure generating arc assisting in the extinguishment of the interrupt ing arc. 2. In a circuit interrupter, a relatively sta tionary contact, an intermediate movable con tact, a movable contact, the stationary contact and the intermediate contact cooperating to es .tablish a pressure-generating arc, the interme diate contact and the movable contact being co operable to establish an interrupting arc, a pres ?led September 18, 1942, Serial No. 458,778, by 30 sure chamber adjacent the pressure-generating Winthrop M. Leeds and Benjamin P. Baker, now arc, an interrupting passage adjacent the inter U. S. Patent 2,372,589, issued March 27, 1945, and rupting arc, passage means extending between the assigned to the assignee of the instant applica pressure chamber and the interrupting passage, tion. Also an application ?led December 26, piston means operatively attached to and mov 1942, Serial No. 470,161, by John B. MacNeill and able With the intermediate contact, valve means assigned to the assignee of the present applica for the piston means operative upon the initial tion describes certain improvements in the con movement of the intermediate contact, the piston cept of operatively connecting a piston to an in means extending across the passage means dur termediate contact in an arc extinguishing struc ing the initial movement thereof, an enlarged ture of the type producing both a pressure gen 40 portion in the passage means, the enlarged por~ erating are and an interrupting arc. tion being so disposed that during the end of the Although We have illustrated a speci?c em travel of the piston means a Icy-passing of ?uid bodiment, it will be clearly understood that the around the piston means is permissible. same was merely for purpose of illustration and LEON R. LUDWIG. that changes and modi?cations may be made WINTHROP M. LEEDS. therein by those skilled in the art without de BENJAMIN P. BAKER.