US2020475A

US2020475A - Electric switch

Info

Publication number: US2020475A
Application number: US651279A
Authority: US
Inventors: Ronnberg Daniel
Original assignee: ASEA AB
Current assignee: ABB Norden Holding AB
Priority date: 1932-01-23
Filing date: 1933-01-12
Publication date: 1935-11-12
Anticipated expiration: 1952-11-12
Also published as: DK49073C; GB408077A; FR45197E; FR749337A; DE894269C; GB409099A; BE404895A; BE393776A; GB423424A; DE912122C; DE912595C

Description

Nov. 12,1935. D. RNNBERG 2,020,475

ELECTRIFC SWITCH Filed Jan. 12, 1935 8 Sheets-Sheet 1 ngi@ Nov. l2, 1935. D. RNNBERG ELEcTRIc SWITCHI Filed Jan. 12, 1953 8 Sheets-Sheet 2 Invenol. 36W/EL Row/#85126.

Nov. 12, 1935. D. RONNBERG ELECTRIC SWITCH Filed Jan. 12. 193s 8 Sheets-Sheet 3 y jfl/egim. :DHA/[5L RONA/BER G v /Oef D. RNNBERG ELECTRIC swITcn Nov. l2, 1935.

Filed Jan. 12. 1933 8 Sheets-Sheet 4 Nov. l2, 1935. D. RONNBERG ELECTRIC swmm Filed Jan. 12. 195s 8 Sheets-Sheet 5 Nov. 12, 1935. D. RNNBr-:RG 2,020,475

ELECTRIC SWITCH Filed Jan. 12, 195s a sheets-sheet 'r ,7n venfor. 'jf/m64 rDN/v B52 6 Nav. 1 2, 1935. D. RNNBERG 2,020,475

' ELECTRIC SWITCH Filed Jan. 12. 1953 a sheets-sheet 8 /ff venor. :D6/WEL PNNEG Patented Nov. 12, 1935 UNITED STATES ELECTRIC SWITCH Daniel Bnnberg, Ludvika, Sweden, assignor to Allmnna Svenska Elektriska Aktlebolaget,

Vasteras, Sweden Application January 12, 1933, Serial No. 651,279 In Sweden January 23, 1932 12 claims. (cl. zoo-15o) The present invention relates to such circuit breakers where the arc of rupture is extinguished by a flow of fluid for instance oil or water or a suitable gas. The invention 'relates further to such circuit breaker, where the flow of iluld is caused by the arc itself. l

In previous constructions of breakers of this `kind a flow of the extinguishing fluid has either beenaccomplished by anauxiliary arc or bya plunger operated by the switching mechanism.

When an auxiliary arc is used for the above mentioned purpose, the breaker usually becomes rather complicated and the use of an auxiliary arc is combined with severe disadvantages especially at closing the breaker chiefly due to electrodynamical action.

In the use of a special plunger. driven from the mechanism, the chief disadvantage is that the driving mechanism in all cases at every interruption must cause the same flow of fluid regardless of the magnitude of the current to be interrupted. As the force necessary to cause a flow suflicient to extinguish a short circuit are is very great, the driving mechanism in this form of breakers has always a considerable load.

Other breakers are also known where a flow of extinguishing fluid is caused by the arc itself, but'in these breakers the vapor developed by the arc acts immediately on the extinguishing fluid which by the pressure of the vapor is pressed in a stream across the path of the arc. In these breakers, the arc therefore must get a rather considerable length before the extinguishing action can take place.

According to the present invention, the ilow of fluid is caused by a plunger mechanism driven by the arc itself. The power available for the plunger mechanism is therefore automatically increased with the current to be interrupted.

According to the invention the contacts of the breaker are enclosed in a chamber which is connected with another chamber by one or a plurality of channels of which one maybe travenlarged detail view showlng in section part of the breaker of Fig. 14; Figs. 16 to 18 inclusive are similar views but showing slightly modified forms; Fig. 19 is a sectional plan view of Fig. 18; and Figs. 20 and 21 are sectional views showing two other forms of the circuit breaker.

Referring to Fig. 1. an oil vessel I is closed by a cover 2. This cover is provided with leading through insulators 3 which are extended into the vesseland supports the stationary contacts 8 and the extinguishing chambers I. S is an insulating 10 rod supporting they movable contacts 6. which are fastened to the rod by means of a bridge 1. 'Ihe extinguishing chambers are shown in an enlarged scale in Fig. 2. In this figure, 9 is the stationary contact supported by the insulator 3. 15 The contact I is provided with shallow contact blocks 9 forming a sleeve contact and supported by the leaf springs I0 and pressed together by the annular formed spiral springs II. The contact 9 is surrounded by a metal sleeve I2, which supports the cylinder il by means of the collar I9, which is connected to the sleeve I2 by four spaced radially extending arms or spokes extending between the collar I6 and the said sleeve I2. This cylinder I3 is made of a suitable insulating material for instance bakelized paper and provided with a cover I4 and bottom I5. The cover I4 and bottom I5 areheld apart by rods I1 and Iprovided with holes I8 and I9 for the passage of the movable contact 6. The hole I8 in the cover Il has nearly the same diameter as the movable contact 6, but the hole I9 in the bottom I5 is considerably greater than the contact. Beneath the bottom I5 a floating cover 20 with a close fitting hole 2i is arranged. Due to the floating arrangement of the cover, the hole can be very close fitting the contact regardless of the movable contact not being in accurate alignment with the axis of the cylinder I3. Surrounding the cylinder I3 a. metal cylinder 22 is arranged, which is provided with a metal collar 23 at its upper end and a bent over edge 2l at its lower end, which close fits the cylinder i3. The collar 23 is close fitting the metal sleeve I2 and is at its inner diameter provided with an annular groove 25. The groove 25 communicates with the extinguishing chamber by openings 29 and with the space outside the chamber by means of the opening I0. The openings 29 are normally 5o closed by valves 2l pressed against the holes by means of helical springs 21.

The device acts in the following manner. When the movable contact 9 separates from the stationary contact blocks 9, an arc between the 55 .consists of a rod and is designated by 4|.

contacts appears, which heats the fluid firstly in the upper chamber 32 and then in the lower chamber 33. Due to the pressure arising in the chambers an upward force acts on the lower side of the collar 23 and a downward force on the bent over edge 24 of the cylinder 22. former force is materially greater than the latter, so that the resulting force will give the cylinder 22 a motion in upward direction. By this motion the space between the

cylinders

22 and 3 decreases and the upper chamber 32 increases, so that fluid is pressed from the first space into the space 33 through holes 3| in the Walls of the insulating cylinder I3 and from there through the hole I8 into the chamber 32. After extinction of the arc, the cylinder 22 is brought back by the helical spring 34 or by its own weight.

The valves 29 are arranged in order to prevent a dangerous pressure to arise in the chambers, and are dimensioned only to open at an excessive pressure. In order to facilitate the departure of gases from the space between the cylinders the collar |6 is provided with small holes 35.

In Fig. 3, the stationary contact is integral with a cylinder 36 which is fastened to the insulator 3. The cylinder 36 is provided with a piston 31 that by means of rods 38 is connected to another piston 39 movable in a second cylinder 40. This may preferably be made of an insulating material and has a diameter materially minor to that of the cylinder 36.k When the movable contact 4| separates from the stationary contact, an arc appears between this contact and the stationary contact 42, and as both cylinders are filled with an insulating uid, this will evaporate and cause a pressure acting upwardly on the piston 31 and downwardly on the piston 39. Due to the diierence in piston area the pistons will move upwardly. At this motion the fluid in the smaller cylinder will be pressed through the hole 43 and thereby extinguish the arc. After extinguishing the arc, the pistons are pressed back by the spring 44.

In Fig. 4, 36 is a metal cylinder fastened to the insulator 3. Said cylinder is provided with a piston 31 which by means of rods 38 is connected to another piston 39, movable in a second cylinder 40. This may preferably be made of insulating material and has a diameter materially minor to that of' the cylinder 36. 'I'he movable contact The stationary contact 42 is yieldably mounted ani electrically connected to the metal cylinder 36. The

cylinders

36 and 40 are separated by a stationary insulating wall 45 and provided with a hole or channel 43, traversed by the movable contact. When the movable contact 4| separates from the stationary contact an arc appears between this contact and the stationary contact 42, and as both cylinders are filled with an insulating fluid, this will evaporate and cause a pressure acting upwardly on the piston 31 and downwardly on the piston 39. Due to the difference in piston-area the pistons will move .upwardly. At this motion the fluid in the smaller cylinder is forced through the hole or channel 43, thereby extinginshing the arc. After the arc has been extinguished the pistons are forced back "to the original position by means of the spring 44.

In 5 and 3 "me are shown where the cyl 11i-ders are .s in relation to each other. @Onespondin :e designated by the same 'figures as i l-: ing iigure. The upper "ce". in this ease also preferably be of TheV metal and the lower cylinder of some insulating material. The stationary contact is also in this case yieldably mounted and an insulating wall 45 is also arranged between the cylinders. Said insulating wall is supported by rods 46 and the 5 piston 31 with the cylinder 40 is forced back to the original position by means of helical springs 41 surrounding the rods 46. The lower cylinder is rigidly fastened to the piston 31 so that when a pressure arises in the cylinders due to the arc of 10 rupture, the piston 31 moves upwards and with it the cylinder 40 with the bottom 39. 'I'he space between the wall and the bottom 39 is then reduced so that a. flow of liquid is forced from said space through the channel 43 into the upper 15 cylinder. In the form shown at Fig. 5 the liquid also passes through the channel 49 and openings 50 in the stationary contact.

Figs. 7, 8 and 9 show modifications where the insulating wall 45 is replaced by a series of walls 20 52 provided with holes forming a longitudinal channel for the arc between the contacts.. In Fig.

7 these walls 52 are arranged a small distance from each other and so also in Fig. 8, but in Fig.

8 the walls are provided with further holes 53 25 arranged on opposite sides, so that a flow of fluid across the arc is obtained. In Fig. 9 a section of the arrangement according to Fig. 8 perpendicular to the section in Fig. 8 is shown.

In Fig. 10 the stationary contact 54 is arranged 30 on a movable plunger 55 that is movable in the cylinder 56. This cylinder is fastened on the insulator 51 and the stationary contact is connected to the cylinder 56 by means of a flexible conductor 58. A spring 59 tends to hold the 35 plunger 55 in its lower position. The plunger 55 is provided with an insulating cylinder 60 and a collar 62. Inside the cylinder 60, a wall 6| is arranged a small distance from the stationary contact 54 and provided with a channel traversed 40 by the movable contact 4|. The cylinder 56 is provided with a cylinder of insulating material 63, that surrounds the cylinder 50. Inside the cylinder 63 the collar 62 of the plunger 55 flts rather well. The bottom 64 of the cylinder 63 is 45 also provided with a channel for the movable contact, and in the plunger 55 a hole 61 is arranged.

The arrangement acts in the following way: When the coniA 't separates from the station- 50 ary contact 54, an are appears between the contacts and causes a violent evaporation of the fluid surrounding the contacts. The pressure generated thereby acts downwardly on the upper r" side of the piston or plunger 55 and upwardly' di on the lower side of said plunger and its collar or fiange 62.. Due to the larger area o the lower surface of the piston 55 it is forced upwards so that the liquid inside the cylinder 56 is compressed. At this compression a powerful flow of liquid is forced through the hole 61 and through the hole in the insulating wail 6| into the space on the lower side of the plunger 55, i. e., into the space enclosed by the flange 62, the wall 6|, the cylinder 63 and the bottom 6ft. As the arc also traverses the 'noie or channel in the wall 6l it is brought into a very intimate contact with said new of liqi'iid. and is therefore rapidly extinguished.. 7C

The arrangement according to Fig. l1 differs from that of Fig. 10 only in that the stationary .contact with the plunger 55 is fixed to the insulator 51 by means of a rod 65. In this arrangement the cylinder 56 with the cylinder 63 is mov- 75 able and is held in its upper position by means of the spring 59.

When the arc appears a pressure arises in the chamber enclosed between the plunger 55 and the bottom 84, and said pressure is also transmitted through the channel 61 in the plunger 55 into the space enclosed by said plunger and the cylinder 50. Due to this vpressure an upwardly directed force acts on the top of the cylinder 53 and a downwardly directed force on4 to the metal part 66, which also supports the.

insulating

cylinders

10 and 13. The cylinder 10 is provided with a wall 1| beneath the stationary contact and the cylinder 13 is provided with the bottom 14. The space on opposite sides of the cylinder 10 communicates by means of holes G8 .in the cylinder 10. Between the cylinders 10 and 13 a metal cylinder 12 is movable. This ylinder is provided with a collar at its lower part with a diameter equal to the inner diameter of the cylinder 13. In this modification the insulating cylinders are stationary and only the metal cylinder movable and held in its lower position by means of the springs 69 which are held in position by means of rods 15. The action of the arrangement is the followmg:

The pressure arising at the appearance of the arc acts downwards on the upper surface of said cylinder. As the part ofthe cylinder 12, which moves in the annular-formed groove in the metal part 86 has a materially smaller sectional area than the area of the lower side of the cylinder 12 with its flange, the cylinder is forced upwards and the space enclosed by said cylinder and said groove isV therefore reduced and liquid forced through thc channel in the insulating wall 1| into the space on its lower side.

The arrangement according 'to Fig. 13 is similar to that of Fig. 12. The insulator 51 supports a metal cylinder 85 that in its turn supports an insulating cylinder 80 provided with a wall 8| beneath the stationary contact. The outer cylinder 83 is movable and may also be provided with an inner metal cylinder 85. The

'cylinder 83 is held in its upperposition by means cf the springs 69 held in position by means of the rods 15. The cylinder 83 is also provided with a bottom 84 provided with a hole traversed by the movable contact 4|. 'I'he metal cylinder 86 is provided with holes 88 for the 'extinguishing iiuid. The cylinder is fastened to the cylinder 82 that also supports the rods 15.

The function of the device is thefollowing:

'I'he pressure generated by the arc' acts downwardly on the bottom 04 and upwardly on the lower surface of the inwardly directed collar of the metal cylinder 85. As the downwardly directed force is materially greater, the cylinder 83 with the metal cylinder 85 and its collar moves downwards whereby the inner rim of said collar slides against the outer side of the metal cylinder 86. At this motion the space between the

cylinders

85 and 80 is reduced and a flow of liquid is forced through the holes or channels 88 into the space inside the cylinder 88 and from there through the channel in the insulating wall 8|.

In Fig.. 14 a form of' the invention is shown, which 1s especially suitable when water is used as van extinguishing fluid. In this gure, 9| are the insulators supporting the stationary contacts 91, which are surrounded by a plurality of cylinders forming an extinguishing chamber. The movable contacts 93 are arranged on a'bridge 94 supported by an insulating rod 95 connected with the operating mechanism not shown on the drawings. The insulators 9| may be suspported by a beam 92 of suitable material. The extinguishing chamber is shown rin detail in Fig. 15.

In this figure, the stationary contact 91 is arranged in the bottom of a vessel formed by the cylinder |94, which is provided with a bottom and with a cover |05. This cylinder may be made of a suitable metal and so also the other.

cylinders surrounding the contacts if only the covers are made of `an insulating material. The stationary contact is yieldably supported by the rmetal cylinder |01 with which it is connected by means of springs |0, bolts |09 and flexible conductors |08. The cylinder 98 is supported by means of pillars |06 fastened at the bottom of the vessel. Close to the cylinder 98 a movable cylinder |02 with bottom |0| is arranged and this latter cylinder is rigidly connected to the cylinder |00 `r'f'ovable in the vessel |04. The cylinderl 99 is provided with a cover 99, so that the stationary contact is entirely enclosed. The movable contact moves through a hole inthe cover 99, and the cylinder |00 is also provided with a cover |93 which` acts as piston. Corresponding to the hole in the cover 99 the covers |03 and |05 are also provided with holes for the movable Contact. The movable contact 93 has a central bore `at its lower part and this bore communicates with the space outside by means of longitudinal channels 98.

This arrangement acts in the following manner: When the contacts separate, an arc appears between the contacts, and a vaporization of the wai-er takes place. In the first moment steam will pass the channels 96 so that the pressure on either side of lthe cover 99 viz. the bottom |0| will be nearly equal. sides of the cover |03 will cause an upward motion of the cylinder |00 and as the cylinder |02 is rigidly connected to the cylinder |00, a ccntractionV of the space inside the cylinder 98 takes place. Due to this contraction a flow of extinguishing fluid is pressed through the hole' in the cover 99 and causes a rapid extinguishing of the arc. Usually the breaker is filled with water up to the line marked by the arrow but less water can also be used.

In Figs. 16 and 17, two modifications of the arrangement according to Fig. 15 are shown. In Fig. 16 the stationary contact I I is provided with a hole and also the cylinder ||2 with a channel ||3, so that in this modification the movable contact need not be hollow. At breaking, the steam will escape 4through the channel ||3 to the space outside the cylinder 98. The modification according to Fig. 17 differs fromthat of Fig. I8 only in that the stationary contact is a sleeve contact with sprung contact blocks |6.

Fig. 18 shows another modification of the form shown in Fig. 15, but in the modification according to Fig. 18 the path of the arc is crossed by a plurality of channels ||9 formed by the' disks ||8 which are shown in plan in Fig. 19.

vIn the form shown in Figs. 14-18. a valve ||1 is provided to avoid excess pressure to arise inside the cylinder next to the contacts.

The pressure on the lower In Fig. 20, a form of the invention is shown where two pairs of contacts are enclosed in one cylinder. In Fig. 20, |2| are the stationary contacts which are supported by the insulators |22 which are fastened in the cover |23 of the breaky bottom |21 as well as the space between the in- 'lating material.

` channels |4| sulators |22 and cover |29 is made as small as possible to avoid oil leakage.

At breaking the arcs formed between the stationary contacts |2| and movable contacts |33 cause a pressure that is transmitted through the openings |32, so that a pressure will act on the lower side oi the cover |29.- On the bottom i2? the pressure on both sides will be equal but act in opposite directions. The cylinder |28, cover |29 and bottom |21 will therefore move upwards and cause a contraction of the space enclos`ng the contacts. Due to this contraction the iiuid enclosed in this space is pressed through the openings |32 and will then come in intimate contact with the arcs.

In Fig. 2l another form of the invention is shown where also two stationary contacts are enclosed in the same space. The stationary contacts are surrounded by a cylinder |36 of insu- Around this cylinder another cylinder i38 is arranged, which may be made of metal. This latter cylinder is provided with a collar iSl which close fits the inner cylinder |36. The cylinder |38 is further provided with a collar |39 at its upper end, which is movable in an annular space i 46 formed by the ,annular parts i3@ and |44. This space communicates by small with the atmosphere. The cylinder 38 with its collar |39 is held in its lower position by means of springs |35.

.Then the pressure caused by the arcs acts on the collar |39, the cylinder |38 moves upwardly and thereby the space between the cylinder |36 and |38 is contracted, so that the huid contained in that space is pressed through the openings |42 into the space in the cylinder |36 and comes then in intimate contact with the arcs.

I claim as my invention:

l. An electric circuit breaker comprising stationary contacts, movable contacts engaging said stationary contacts, a chamber enclosing the contact point between cooperating stationary and movable contacts, a chamber adjacent to said chamber, a differential piston forming parts of the walls of said chambers and actuated by the pressure generated by the arc of rupture, a channel spaced from said contact point and forming the principal communication between said chambers, said channel being opened by the movable contact during the rupturing motion, and being traversed by fluid diplayed by said piston.

2. An electric circuit breaker comprising stationary contacts, movable contacts engaging said stationary contacts, a chamber enclosing the contact point between cooperating stationary and movable contacts, a chamber adjacent to said chamber, a differential piston forming parts of the walls of said chambers and actuated by the pressure generated by the arc of rupture, a channel forming the principal communication between said chambers, said channel being traversed by a flow of fluid forced forward by action of said differential piston and by the arc of rupture.

3. Anelectric circuit breaker comprising stationary contacts, movable contacts engaging said stationary contacts, a chamber enclosing the contact point between cooperating stationary and movable contacts, a chamber adjacent to said chamber, a differential piston forming parts of the walls of said chambers and actuated by the pressure generated by the arc of rupture, a plurality of channels forming the principal communication between said chambers and traversed by a flow of fluid, one of said channels being traversed also by the arc.

4. An electric circuit breaker comprising stationary contacts, movable contacts engaging said stationary contacts, a chamber enclosing the contact point between each pair of cooperating stationary and movable contacts, a chamber adjacent to said chamber, a differential piston forming parts of the walls of said chambers and actuated yby the pressure generated by the arc oi rupture, a channel forming the principal communication between said chambers, said channel being traversed by the movable contact, by the arc of rupture, and by a flow of fluid from one chamber to the other.

5. An electric circuit breaker comprising stationary contacts, movable contacts engaging said stationary contacts, concentrical cylinders movable in relation to each other, annular and disc formed parts connected to said cylinders and forming with the said cylinders for each pair of contacts two chambers with different cross section, a differential piston comprising parts of the walls of said chambers rigidly connected together and movable in said chambers, a channel connecting said chambers and traversed by the movable contact, by the arc of rupture, and by a flow of extinguishing fluid forced forward by Said differential piston.

S. An electric circuit breaker comprising stationary contacts, movable contacts engaging said stationary contacts, concentrical cylinders movable in relation to each other, annular and disc formed parts connected to said cylinders and forming with the said cylinders for each two engaging contacts two chambers with different cross section,. a differential piston comprising parts of the walls of said chambers rigidly connected together and movable in said chambers, a stationary wall of insulating material placed at a small distance from the stationary contact and separating the two chambers, a channel in said wall traversed by the movable contact, by the arc 0f rupture and by a flow of fluid from one chamber to the other.

7. An electriccircuitbreakercomprisingstationary contacts, movable contacts engaging said stationary contacts, concentrical cylinders movable in relation to each other, annularanddiscformed parts connected to said cylinders and-ftogether with the said cylinders-forming, for eachtwoengaging contacts, two chambers with different cross section, a differential piston comprising parts of the walls of said chambers rigidly connected together and movable in said chambers, a stationary wall small distance from the stationary contact and separating the two chambers, a channel in said wall traversed by the movable contact, by the arc of rupture, and by a ow of iiuid from one chamber to the other, a oating disc closing one of said chambers, and a channel in said disc traversed by the movable contact andtightly fitting to it.

8. An electric circuit breaker comprising containers partly iilled with an extinguishing liquid, stationary contacts arranged beneath the surface of said liquid, movable contacts engaging said stationary contacts, a diierential pressure device comprising, concentrical cylinders movable in relation to each other, and disc shaped parts connected to said cylinders and forming chambers enclosing said contacts, a channel connecting rsaid chambers andtraversed by a iiow of liquid from one chamber to the other in contact with the arc of rupture between the contacts'.

9. An electric circuit breaker comprising a plurality of stationary contacts, a plurality of movable contacts engaging said stationary contacts, a cylinder surrounding said contacts, a movable bottom for said cylinder, a container enclosing said contacts, a piston rigidly connected to said movable bottom and movable in said container, and channels in immediate proximity to the point of engagement of said contacts.

' 10. An electric circuit breaker comprising stationary contacts, movable contacts engaging said l stationary contacts-two chambers changeable in volume and enclosing said stationary and movable contacts, means for changing the volume of said chambers in opposite senses by the action of insulating material placed at a of the arc o! rupture. a stationary wall separating said chambers and arranged in front of said stationary contact, a channel in said wall traversed by the movable contact and arc of rupture, one or a plurality of valves closing channels between said chambers and the space outside the chambers, said valves preventing an excess pressure in the chambers.

1l. An electric circuit breaker comprising a container partly illled with an extinguishing liquid, a stationary contact arranged beneath the surface of said liquid, a movable contact engaging said stationary contact, a stationary cylinder' surrounding said stationary contact, a stationary cover in said cylinder arranged in front of said stationary contact, a channel in said cover traversed by said movable contact, a movable cylinder'arranged outside said stationary cylinder, a bottom part and a cover iixed to said cylinder, each closing a'chamber formed by 20 said cylinders and enclosing said contacts.

12. An electric circuit breaker comprising a plurality of containers partly lled with an extinguishing liquid, a stationary contact in each container arranged beneath the surface of said liquid, a movable contact engaging said stationary contact, a stationary cylinder surrounding said vstationary contact, a stationary cover in said cylinder arranged in front of said stationary contact, a channel in said cover traversed by said movable contact, a movablev cylinder arranged ouiside said stationary cylinder, a bottom part and a cover nxedto said movable cylinder. `each closing aehamber formed by said cylinders and enclosing said contacts, a plurality of valves arranged in the walls of said chambers in order to prevent excess pressure inside the chambers.

DANIEL RNNBERG.