US2022241A

US2022241A - Circuit interrupting device

Info

Publication number: US2022241A
Application number: US671823A
Authority: US
Inventors: Kopeliowitsch Jakob
Original assignee: BBC Brown Boveri France SA
Current assignee: BBC Brown Boveri AG Germany; BBC Brown Boveri France SA
Priority date: 1932-06-02
Filing date: 1933-05-19
Publication date: 1935-11-26
Anticipated expiration: 1952-11-26
Also published as: GB412403A; NL36467C; BE396640A; DE626961C; DE638580C; FR756311A; NL36382C; GB414491A; NL65476B

Description

'Ncw,` 26, 193521 J. KoPr-:uowlTscH 2,022,241

` CIRCUIT INTERRUPTING EEVICE Filed Mayk 19, 1933 2 Sheets-Sheet l Nov. 26, 1935. J. vKoPELlowlTscH CIRCUIT INTERRUPTING DEVICE 2 Sheets-Sheet 2 Filed May .19, 1953 S g s Patented Nov. 2s, 193s UNITED STATESg CIRCUIT INTERRUPTING DEVICE Jakob Kopeliowitsch, Baden, signor to Aktiengesellschaft Switzerland, asi Brown Boveri &

Cie.,- Baden, Switzerland, a joint-stock company of Switzerland Application May 19, 1933, Serial No. 671,823 In Germany June 1, 1932 11 Claims. (Cl. 200-150)` This invention relates in general to circuit interrupters having pressure pots provided with means for regulating the discharge of arc extinguishing fluid across the arc in accordance with the pressure generated within the pot, and more particularly to circuit interrupters in which such regulated discharge action commences during the initial circuit interrupting action.

To accelerate the interruption oi' alternating current arcs in heavy duty circuit breakers the so-called explosion pots as well as other devices have been used. Heretofore these explosion pots generally have been provided with only one nozzle opening through which the movable contact rod may move. As long as the movable contact rod is within the chamber the nozzle opening is so restricted that it is difficult to design the walls of the pressure chamber suiiiciently strong to hold the pressures generated by the arc within the pot.

To overcome this diiiculty explosion pots containing a certain volume of air have been proposed, the air being compressed by the pressure generating arc, however, such arrangements have not proven to be practical because the turbulence of the liquid within the pot causes most of the air to be ejected from the pot. Pres- 'sure chambers having additional fixed openings for the discharge of gas have also been proposed, however, such arrangements are not effective to produce a vigorous blast of arc extinguishing liquid through the arc when the current to be interrupted is of small magnitude. Pressure chambers having valve controlled openings for the discharge of gas have also been proposed, however, in such arrangements the energy of the gas escaping through these openings is wasted inasmuch as it is not caused to flow through the arc.

It is therefore an object of this invention to provide a circuit interrupter with a pressure pot having a pressure controlled discharge opening which utilizes the energy of the discharged iiuid to cause a blast of arc extinguishing iiuid to il'ow across the arc before leaving the pressure pot.

Another object of the invention is to provide a circuit interrupter with a pressure pot havingA a restricted passageway for a movable contact and a valve controlled discharge opening in com- `munication with anV annular arcing contact member for causing the iiuid discharged through said opening to flow across the points of attachment of the arc on the arcing contact member.

It is an object of the invention to provide a 4circuit interrupter with a pressure pot having a passageway for the movable contact sufilciently restricted so as to eiilciently extinguish an arc at smaller currents and pot pressures and to provide a means controlled by excessive pot pressures caused by greater currents for relieving the excess pressure and utilizing such excess pressure in extinguishing the arc.

A further object of the invention is to provide a circuit interrupter of the pressure pot `type with a bushing supported bearing member and a pressure pot supporting member having cooperating sockets and projections 'for preventing the rotation of the pressure pot relative to the insulating bushing.

A still further object oi' the invention is to 15 provide improved details ofvfconstruction of a circuit interrupter of the pressure p ot type various novel features of which will be apparent from the description and drawing herein, and will be more particularly pointed out in the claims.

Various illustrative examples of this invention are shown in the accompanying drawings in which:

Fig. 1 is a sectional side view of a circuit 25 breaker of the pressure pot type embodying features of the invention.

Fig. 2 is a top view of the supporting memberA shown in Fig. 1 detached from the insulating bushing.

Fig. 3 is a sectional side view of the supporting member, valve and contact assembly taken along line III-III of F18. 2.

Fig. 4 is a sectional side view of a structure similar to Fig. 3 and within the scope of the in- 35 vention.

Fig. 5 is a sectional side view of another form of pressure rpot assembly embodying the invention.

y Fig. 6 is a sectional view of a modled form of 40 vsupporting member, valve, and contact structure embodying the invention.

Fig. 7 is a side view of the contact sleeve shown in Fig. 6.

Fig. 8 is a top sectional view of contact and 45 valve structure shown in Fig. 6 taken along the line VIII-VIII.

Referring now to Fig. 1, circuit breaker tank I I contains an arc extinguishing fluid I2 and has an insulating bushing I3 angle to the vertical. The lower end of bushing I3 is provided with a bearing plate I4 secured thereto by suitable means such as cement I5. A truncated supporting member I6 is held in engagement with bearing plate Il by means of an 55 projecting thereinto at an assembly conductor rod yalso provided with a bleeder vent I1 and is prevented from turning relative to plate I4 by means of projections I8 thereon which cooperate with corresponding recesses in bearing plate I4. Supporting member I6 is provided with an axial bore I9 in which the stationary contact structure is mounted as will be-described hereinafter.

Ring member 2i is secured to supporting member I6 in spaced relation thereto by a plurality of stud bolts 48 in a manner better shown in Figs. 2 and 3. The opening through ring member 2| is provided with a nozzle member 22 here shown-as of insulating material dening an axial discharge passageway 23. Ring member 2I is 20 which permits the pressure pot to refill with arc extinguishing fluid by discharging the gas remaining in the top of the pressure pot after a circuit interrupting operation. An upper contact structure is provided with a butt contact 24 detachably secured to contact tube 25 which is slidable in axial bore I9 and is biased downwardly by spring 26. An annular valve plate 21 preferably of metal closely surrounds contact tube 25 and is biased into engagement with plate 2I by means of springs 26 in such a manner that discharge passageway 23 is normally closed. A conducting ring 26 is welded or otherwise secured to contact tube 25 and connected to this ring are a' plurality of pigtail conductors 3I which are connected to supporting member I6.

A pot member 32 preferably of insulating material is secured to ring member 2| by suitable clamping means such as clamping ringl 33 and bolts 35, noting that a gasket 34 is inter-posed between the upper edge of the pot member 32 and ring 2i. Within the pot member perforate

baffle plates

36, 31, 38 and 33 may be secured in spaced relation by means of a plurality of spacers 4I, 42, 43 and 44 and retaining ring 45. In some instances it is desirable that the above described baille plates be omitted. The xlower end of pot member 4I is provided with a throat bushing 46 preferably of insulating material adapted to withstand the heat of arc currents. A movable contact rod 41 is adapted to be moved by conventional mechanism (not shown) through the contact openings in throat bushing 46 and the perforations in baille plates 36 to 39, inclusive, into engagement with butt contact 24, noting that these baille plates preferably closely surround contact rod 41 so that the movement of arc extinguishing fluid in a downward direction is limited while the contact rod 41 is within the pressure pot.

Figs. 2 and 3 show more in detail the manner in which ring member. 2I is secured to supporting member I6 by'means of stud bolts 43. It is to be noted that valve plate 21 is provided with a plurality of holes through which stud bolts 43 pass thus serving to guide the movement of valve plate 21. As shown in Fig. 3 the downward movement of contact tube 25 is limitedby conducting ring 2S abutting against the upper face of valve plate 21. A vent passageway 49 from axial bore I6 permits uid within this bore to be displaced when contact 24 is moved upwardly. Valve plate 21 may be provded with a small vent opening 5|! to permit gases from passageway 23 to escape from the pot after the circuit breaker has operated.

4As to the operation of the circuit breaker disclosed in connection with'Figs. 1, 2 and 3, upon downward movement of contact rod 41 an arc will be drawn between butt contact 24 and the top o! contact rod 41. This arc will generate pressure noting' that while contact rod 41 is moving through the openings in baiile plates 36 to 39, inclusive, and through throat bushing 46 valve control passageway 23 is substantially the only exit for arc extinguishing iiuid and gas. When the pressure has built up sumciently to raise valve plate 21 against compression springs 26 a discharge of arc extinguishing uid will iiow from the interior of pot member 32 through the arc and out of the pot through discharge passageway 23. As the pressure increases or decreases valve plate 21 will raise or lower to control or regulate the eiective cross section of the discharge passageway thereby maintaining suflicient pressure .within the pressure pot to cause a vigorous blast of arc extinguishing fluid through the are. If the arc persists or is reignited after passing through a zero current condition the arc extinguishing uid between the various baille plates will flow into the arc stream thereby causing an additional arc extinguishing action. If the arc still persists after movable contact member 41 is completely withdrawn from throat bushing 46 a downward blast ilow.through the throat of bushing 46 and will extinguish the arc in a manner accomplished by the conventional explosion pot construction. It is to be noted that inFig. l the arc will attach to butt contact 24 and will pass through insulat- 'f ing nozzle 22 whereas in a structure such as shown in Fig. 3 the arc will attach to the metal arcing ring 5I after the contacts have separated a predetermined amount and this arc will be acted upon by arc extinguishing iluid owing into passageway 23.

Fig. 4 shows a structure substantially the same as Fig. 3 except that the truncated supporting member- I6 is bolted to a bearing plate 53 by means of a flanged portion 52. This construction is particularly useful where it is desired to use an oil nlled insulating bushing such as shown by I3. Downward movement of contact tube 25 is prevented by a retaining ring 54 which cooperates with a shoulder on contact tube 25.

In Fig. 5 truncated supporting member 55 is provided with projections I6 and a threaded hole for assembly rod I1 so that the pressure pot shown in this figure may.be secured to and removed from a bearing plate such as shown by I4 in Fig. 1. Supporting member 55 is welded or otherwise secured to a supporting plate 56. A ring member 51 is secured to supporting plate 66 in spaced relation thereto by means of a plurality of circumferentially spaced stud bolts 56. An

annular cage member 59 is bolted or otherwise secured to the bottom face of ring member 51 and is provided with an opening in the upper end thereof in which vtubular contact member 6I is secured. The inner walls of contact member 6I define a portion of a discharge passageway 66. A plurality of contact segments 62 are circumferentially arranged around tubular contact member 6I and are biased into contacting engagement therewith by means of upper springs 64. The lower portions of contact segments 62 are biased laterally into passageway 66 by means of lower springs 63. An annular ring member 65 preferably of metal is secured to cage member 59 and serves as an arcing contact member, however, it is to be noted that in some instances it is desirable that this member be made of insulating material in which event it serves as a baille plate. Passageway 66 is normally closed by valve of arc extinguishing uid Will f plate 61 by means of

springs

63 and 53 noting that 75 stop member 1| serves to limit the upward movement of valve plate 61. A plurality of guide pins 12 are circumferentially spaced around valve plate 61 and serve to guide the movement of this valve plate.

A, shell member 13 as here shown is secured to cage member 59. For low voltages this member may be of metal, however, for high voltages it is preferable that insulating material be used. A throat bushing 14 is secured to shell member 13 by suitable means and is provided 'with a contact passageway therethrough for the movement of movable contact member 15 with small clearances therebetween. Contact rod 15 is secured to bridging member 16 which is operated by conventional mechanism (not shown).

As to the operation of the apparatus shown in Fig. 5, upon initial separation of contact rod 15 and contact segments 62 an arc will be drawn therebetween which generates pressure. When this pressure exceeds a predetermined value contact plate 61 will raise and permit a blast of arc extinguishing fluid to flow across the arc and through passageway 66 to the exterior of the pressure pot. As the pressure within the pressure pot increases or decreases valve plate 61 will raise or lower to regulate the discharge of fluid from the pot by controlling the eilective cross sectional area of the discharge blast. When contact rod 15 is withdrawn from throat member 14 an additional blast downwardly through the contact passageway in throat member 14 is available for extinguishing any arc that may persist. It is'to be noted that the above described stationary contact structure affords a novel means for conducting current from a movable member to a stationary member without the use of pigtail connections inasmuch as upper springs 64 bias the upper portion of contact segments 52 into contacting engagement with tubular contact meinber 6|.

In Fig. b', a truncated supporting member 1T is adapted to be secured to an insulating bushing as shown in Fig. 1. Ring member 2| is secured to supporting member 11 in spaced relation thereto by means of stud bolts 18. The opening in ring member 2| is provided with a bushing 19 through which slotted contact tube 8| (more clearly shown in Fig. 7) is adapted to slide. Contact tube 8| has a conducting ring 29 secured 'thereto and is biased in a downward direction by Contact spring 84. Annular contact 82 is removably secured to contact tube 8| and is adapted to cooperate with movable contact 88 which is provided with an arcing tip. A valve member 85 is provided with a plurality of projections adapted to extend through the slotted portions of contact tube 8| and these projections normally rest upon bushing member 19. Valve spring 8S normally biases valve member 85 to the position shown in which passageway 23 through the tubular contact is closed.

By referring to Figs. 6, 7 and 8 it will be seen that upon occurrence of excessive pressure generated by an arc drawn between contacts 82 and 88 valve member 85 will raise against the pressure of springs 84 and 88 inasmuch as conducting ring 29 rests upon the projecting portions of valve 85 after contact rod 83 has been withdrawn, thereby opening a plurality of vents for the discharge of arc extinguishing iluid through the arc and through passageway 28f`and out of the pot through `the slots in contact tube 8|. It is thus seen that valve 85 is capable of regulating the effective cross sectional area of the fluid discharged from the pressure pot in accordance with the pressure within the pot.

Although but a few embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

It is claimed and Patent:

1. A circuit interrupter comprising a pressure pot containing an arc extinguishing fluid and having a movable contact passageway through one end thereof, a contact structure mounted l5 adjacent the other end of said pot in axial alinement with said passageway, a contact member of substantially the same cross sectional size as said passageway movable through said passageway to draw a pressure generating arc between said contacts and within said pot, means including a second discharge passageway surrounding said contact structure whereby said arc extinguishing iluid flows across the points o1' attachment of said arc on said contact structure and to the exterior 25 of said pot, and valve means surrounding a portion of said contact structure and normally closing said discharge passageway, said valve means being operable to open said discharge passageway only when the pressure within said. pot exceeds a predetermined magnitude.

2. A circuit interrupter comprising a pressure pot having alined openings in the top and botdesiijed to secure by Letters rtom thereof and containing an arc extinguishing iiuid therein, an arcing contact structure secured a5 to said pot and having an aperture in alinement y with the alined openings in said pot, a spring biased stationary contact structure mounted on said pot adjacent the top opening in said pot, a

movable contact member normally extending 40 I through the opening in the bottom of said pot and the aperture in said arcing contact structure into engagement with said stationary contact structure and withdrawable to establish a pressure generating arc which attaches to said arcing contact structure, valve means normally closing the opening in the top of said pot and openable upon generation of a predetermined pressure within said pot to permit arc extinguishing fluid to ilow across said arc and through the aperture in said arcing contact structure and through the opening in the `top oi' said pot.

3. A circuit interrupter comprising a pressure pot containing an arc extinguishing iiuid, said pressure pot having axially alined openings in the top and bottom of said pot, at least one baille plate within said pot having a hole therein in alinement with said openings, an arcing contact member secured in the top opening in said pot and provided with an axial passageway therethrough, a resiliently mounted contact member arranged in said axial passageway so as to define a discharge vent therebetween, a contact rod normally extending through the bottom opening in said pot into engagement with said resiliently g5 mounted contact member and withdrawable through the opening in the bottom of said pot to draw a pressure generating arc which attaches to said arcing contact member and causes a pressure blast of arc extinguishing fluid to flow across the points of attachment of said arc on said arcing contact and out of said pot through said discharge vent, and valve means surrounding said resiliently mounted 'contact member for preventing the ilow of arc extinguishing fluid out of said discharge vent until the pressure within said pot exceeds a predetermined value.`

, 4. A circuit interrupter comprising a supporting member, an annular ring member secured to said supporting member in spaced relation thereto, a valve member covering the opening in said annular ring member, spring biasing means arranged between said supporting member and said valve member, a pressure pot member secured to said annular ring member and having a contact passageway therein, a stationary contact structure arranged within said pot member concentrically of said annular ring member, a contact member movable through said contact passageway for connection and disconnection with said stationary contact structure.

5. A circuit interrupter comprising a supporting member, an annular plate member bolted to said supporting member in spaced relation thereto, a valve member covering the opening in said annular plate member, spring biasing means arranged between said supporting member and said valve member, a pressure pot member of insulating material secured to said plate member and having a contact passageway therethrough, a stationary 'contact assembly secured within said pot member to said plate member, said assembly comprising a plurality of spring biased contact segments annularly arranged to form a passageway communicating with the opening in said annular plate and comprising an annular arcing plate forming a portion of said passageway and a contact rod movable through said contact passageway and through the opening in said annular arcing plate into engagement with said contact segments.

6. A circuit interrupter comprising'a supporting member, a ring member secured to said supporting member in spaced relation thereto and having a centrally located opening therethrough, a spring biased contact member slidably mounted in said supporting member and arranged to project into said opening, a valve member surrounding said contact member and normally closing said opening, spring biasing means arranged between said supporting member and said valve member, a pressure pot member secured to said ring member and having a contact passageway, therethrough, and a contact rod movable through said contact passageway into engagement with said spring biased contact.

7. A circuit interrupter comprising a supporting member, a ring member secured to said supporting member in spaced relation thereto and having a centrally located opening therethrough, an annular arcing contact member secured to said ring member and having a passageway therethrough, a spring biased contact member slidably mounted in said supporting member and arranged to project into the passageway in said arcing contact member, a valve member surrounding said contact member and normally closing said opening, spring biasing means arranged between said supporting member and said valve member, a pressure pot member secured to said ring member and having a contact passageway therethrough, and a contact rod movable through the contact passageway in said pot member into engagement with said spring biased contact.

8. A circuit interrupter comprising a supporting member, an annular ring member secured to said supporting member in spaced relation thereto, a tubular contact member extending through the opening in said annular ring member and having a plurality of discharge openings therein, a valve member slidable within said tubular contact member, a. spring abutting against said supporting member and arranged to normally bias said valve member to a position wherein said discharge openings are closed, a pressine pot member secured to said ring member and having ,a contact opening therein, and a contact rod movable through said contact opening to draw an arc within said pressure pot member.

9. A circuit interrupter comprising a supporting member, an annular ring member secured to said supporting member in spaced relation thereto, a tubular contact member slidable through the opening in said annular ring member and having a discharge passageway therethrough, a spring for biasing said tubular contact to a limit position, a valve member slidable within said tubular contact member, a. spring abutting against said supporting member and arranged to normally bias said valve member to a position wherein said discharge passageway is closed, a pressure pot member secured to said ring member and having a contact opening therein, arc extinguishing liquid within said pressure pot member, and a contact rod movable through said contact opening to draw a pressure generating arc within said pressure pot member.

10. A circuit interrupter comprising a truncated supporting member, a ring member secured to said supporting member in spaced relation thereto and having a centrally located opening therethrough, a spring biased contact member slidably mounted in said supporting member for limited axial movement into the opening in said ring member, flexible current carrying conductors connected between said contact member and said supporting member, an annular valve member surrounding said contact member and normally closing the opening in said ring member, spring biasing means abutting against said supporting member for biasing said valve member to its closed position, a pressure pot member secured to said ring member and having a contact passageway therethrough and a contact rod movable through said contact passageway into engagement with said spring biased contact mem- 50 ber.

11. A circuit interrupter comprising a pressure pot having openings in the top and bottom there.; of and containing an arc extinguishing iluid therein, an arcing contact structure secured to said pot and having an aperture, a spring biased stationary contact structure mounted on said pot adjacent the top opening in said pot, a movable contact member normally extending through the opening in the bottom of said pot and the aperture in said arcing contact structure into engagement with said stationary contact structure and withdrawable to establish a pressure generating arc which attaches to said arcing contact structure, valve means normally closing rthe opening in the top of said pot and openable upon generation of a predetermined pressure within said pot to permit arc extinguishing fluid to iiow across said arc and through the aperture in said arcing contact structure and through the open- 7