US2648743A

US2648743A - Exhaust passage and trap means coextensive with arc runners

Info

Publication number: US2648743A
Application number: US203084A
Authority: US
Inventors: Philip L Taylor
Original assignee: Allis Chalmers Corp
Current assignee: Allis Chalmers Corp
Priority date: 1950-12-28
Filing date: 1950-12-28
Publication date: 1953-08-11
Anticipated expiration: 1970-08-11

Description

Aug. 11, 1953 P. TAYLOR EXHAUST PASSAGE AND TRAP MEANS COEXTENSIVE WITH ARC RUNNERS Filed Dec. 28, 1950 of barrier plates.

Patented Aug. 11, 1953 i; EYCHAUS'LPAS SAGE AND :TR-AP S GOEXTENSIVE WITH BUNNIQRS Philip L. ;Taylor,T'Abington,""Mass., assignor to Allis-GhalmeryMan waukee, Wis.

ufacturing Gmpa.ny,-Mil- ApplicationDece nber 28,-195.0,-Serial No. 203,084

8 Claims.

' This invention relates to circuitinterruptin devices and more particularly to circuit breakers of the air break type wherein an .arcestablished between separable contacts is transferred .along arc runners into an. arc extinguishing chute.

The interruption of. heavy current power. arcs is often accompanied by the emission of a great deal of are products includingincandescent metal particles or. other inorganic substances. "These.

i particles, if not confined or eliminated from the arc path, reduce the dielectric strength oi .the

surrounding air and thereby. increase thetime necessary to extinguish the arc or-causeiailure of the circuit breaker.

In accordance with the inventioniclaimed a new and improved circuit interrupting device is provided comprising. relatively movable; contacts which are actuated to initiate andelongate. an arc therebetween. The are isthen transferred along a pair of spaced arc. runners ,fromfthe region of arc initiation to a region. remote therefrom. Trap means may be provided substantially coextensive with all or portions. of .the arc runners for reducing the free flow. of products of arcing from the arcing contacts and are runner in the general direction of the arc path} Fllue or chimney means are arranged substantially coextensive with the arc runners and coextensive with the trap means, if used, to exhaust toatmosphere or a low pressure regionthe hot gases stripped in whole or in part of the-products of arcing.

It is, therefore, one object of the..,invention to minimize the products of :arcingwhich are 7 propagated into the interrupting'zone between the arc runners.

Another object of this invention isvto dispose of the products of arcing whicharegenerated at the arc terminals by trapping, bypass orbleed nets of arcing before being exhausted toatmos-' phere or a low pressure region.

Another object of this invention .is to provide a new and improved arc interrupting dexgice in which the products of arcingand hotgases sure. rounding the arc runners are cooled. and exhausted directlyto atmosphere or. a..low..-pressure region without. passing throughlan arcdeionizing zone which is generally formed of .a stack jA;further. object of this invention is to provide a, newand improved arc interrupting devicein whicl 1 a trap means for inhibiting the free flow of the products of arcing to the space between a gpair of spacedarc runners is associatedwith iiue..mejans forbleeding off or exhausting direct- 1y to atmosphere-the products of arcing.

g, Objects and advantages other than those above set. forthwill be apparent from the following description when read in oonnection'with the accompanying drawing, in which:

" Fig. 1 is a view in cross section, of a magnetic blowout type circuit breaker employing the prestrap, and flue means ent invention;

. Fig. 2is a'plan view of thearc chute and contact structure shown in Fig. 1;

Fig. 3 is a partial side view onan enlarged scale'of the head runner and the trap means andfiue means associated therewith; and f Fig. 4 is a cross section of the head runner, illustrated in Fig. 3 taken along theline IVI "Referring 'more particularly to the drawings by characters'of reference, Fig. 1- illustrates a magneticgblowout type of circuit breaker inin Fig.1. are provided with a plurality of simi- Hlar'pole structures, one for each phase of a polybreaker will bedescribed in phase. electric circuit, only one such pole structure is. shown in the drawing and the circuit detail as if it was of the singlepole unit type.

The circuit interrupter or breaker in Fig. 1

comprises essentially means for opening the cirtinguishing structure.

cuit to form the interrupting arc and an arc ex- Specifically, the circuit opening means, comprises a fixed contact aslsembly supported onan insulator l5 and includ- .ing acurrent carrying contact' [8, tertiary ,con-

'tactsjl 9, and arcing contact 20, cooperating "with I amovable, contact 2| comprising current carrying tertiary and arcing contact combined in a ,..s ing1e,structure. .Movablearcing. contact 2| is mounted on alever 22 which ispivotally mounted at .23 on an extension 24 of the circuitbreak- .er ,stud l6 and is operated by means "of a .,25, is, suitably connected to an.

reciprocally movable rod 25. The operating rod actuating] mech- ,..anism (not'shown) for operating'the'movable contact, betweenclosed and open. circuit positions. 'Fig. 1 illustrates the movable contact 2| in closed position. The arcing contacts gare electrically connected to the lower ends of terminal studs l6 and ll. Accordingly, when the breaker is connected in series in a power circuit and the arcing contacts are separated, an arc may be initiated across the gap formed between the contacts.

For the purpose of interrupting this power arc, an arc extinguishing structure, such as an arc chute 30, may be mounted so as to receive the power are which is under the influence of a magnetic blowout means. erably is disposed directly above the arcing contacts, as shown, when the blowout means act upward, but may be mounted in any other suitable location when the blowout means act in other directions. The switch or arcing contacts The are chute pref-' 4 from each other to provide a passage .tll-ferebetween and along the

arc runners

34 and 35 for the arc to travel during its movement into and through arc chute 30.

In accordance with the invention claimed,

. chimney passages or flue means 42 and 43 are and the magnetic blowout structure can assume any preferred form so that a brief description thereof will be sufficient. The magnetic blowout means may comprise a core 3|, poles 32, and a coil 33. The latter is electrically connected to the terminal stud H and, through a strap 28, to arcing contacts 2|) and to a metallic arc runner 34 so that the arc current (as the arc travels along the runner) flows through the blowout coil in a manner well known in the art.

Normally the current is carried in the closed circuit position of the breaker by contact 2| and the spring biased contact l8. While the movable arcing contact 2| is actuated to open circuit position, current is shunted from fixed contact l8 first to fixed contact 19 and then to fixed arcing contact 20'. As the arc is drawn by the movable arcing contact 2|, the arc terminal on arcing contact 24 is transferred to are runner 34 which is adjacent to and connected to contact 29 but separated therefrom by a gap 29. The arc termi nal is driven across gap 29 to reach a flat side of arc runner 34. When the movable arcing con;

tact 2| approaches a predetermined position in its opening stroke, the other arc terminal transfers from the movable arcing contact 2| to an arc runner which directs the are into the arc chute 3B. When the movable arcing contact 2|, contact IS, the flow of current is parts from transferred from contact I9 to contacts 23 through the blowout coil 33. The movable arcing contact 2| subsequently parts from contact 23 to draw an arc. Accordingly, the blowout coil is already energized at the inception of the arc interruption to influence the arc in a well known manner, i. e., to drive it into the arc chute in an expanding loop. It will be apparent to one skilled in the art that the blowout field can be utilized in the most efiicient manner by disposing the iron poles 32 so as to cooperate with the blowout coil in the conventional manner outside'of the arc chute.

A pair of insulating plates 36 and 31 (more clearly illustrated on an enlarged scale in Figs. 3 and 4) are arranged to extend within the are receiving end of chute'3il to capture the incandescent particles emitted from the arcing contacts 20 and 2| and the

arc runners

34 and 35 as the arc is moved into the arc chute. "The end section of the

plates

35 and 37 are spaced from

arc runners

34 and 35 and arranged substantially coextensive with sections thereof for providing pockets or trap means 38 and 39. The trap means 38 and 39 inhibit the free flow of incandescent particles from the arcing contacts and are runners to the space surrounding the are as it is being elongated and introduced into the barrier structure of arc chute 34. As illustrated in Fig. 4, plates 36 and 31 may be spaced apart ,the axis of arc chute 30'.

arranged substantially coextensive with the

arc runners

34 and 35 and the trap means 38 and 39, respectively, for cooling and exhausing to atmosphere or a low pressure region the product of arcing. Flue means 42 and 43 extend from the arcing contacts 20 and 2|, that is the region of arc initiation along the arc runners and through the are chute 33, but outside of a barrier structure v44 to atmosphere. Barrier structure 44 comprises a plurality of spaced insulating plates which are arranged to extend longitudinally of g The flue means 42 and 43 are arranged withportions thereof substantially coextensive with the arc runners and are preferably also coaxial therewith. Under normal interrupting conditions an arc is initiated immediately upon separation of the arcing contacts 20 and 2|. The terminal of the are on fixed arcing contact 20 is driven across gap 29 over the flat section of arc runner 34 toward the exhaust end of arc chute 30 by the magnetic blowout means and the thermal effect of the are. As movable arcing contact 2| approaches its fully open position the other terminal of the arc jumps from contact 2| to the flat arc runner 35 and is also driven by the blowout means and the terminal effect of the arc toward the exhaust end of arc chute 30.

Upon initiation of the arc and also during its movement along the

arc runners

34 and 35, emission of are products including incandescent metal particles or other inorganic substances occurs which heretofore were jetted into the area surrounding the elongated arc. These incandescent particles reduce the dielectric strength of the air or other gas surrounding the arc, thereby increasing the possibility of reignition or restriking of the are after it was extinguished.

By providing flue means 42 and 43 adjacent the point of arc initiation, along the arc runners and through the arc chute to atmosphere, the products of arcing produced in these regions are cooled and the hot gases are exhausted directly to atmosphere before the arcing products and hot gases can lower the dielectric strength of the air surrounding the elongated arc.

The walls forming the flue means 42 and 43 may serve as trap means, or trap means 38 and 39 may be used in addition to the flue means to'collect and strip the hot gases of the incandescent products of arcing. Flu means 42 and 43 bypass the stack structure 44 to exhaust the hot gases directly to atmosphere. In order to increase the-operating effect of fiue means 42 and 43, the cross section area of the flue is made relatively large compared to the cross sectional area of the spaces between adjacent barrier plates 44. Thus, the hot gases and are products emitted from the arcing contacts, are runners, and surrounding circuit breaker structure will exhaust to atmosphere through the flue means 4 2 and 43 and will not have a tendency to diffuse through the barrier structure 44 where they would contaminate the arc path.

Trap means 33 and 39 being disposed immediately adjacent the point of arc inception, the region of initial arcing on the arc runners, and the region where the arc is being elongated by the diverging section of the'arc runners inhibit aeusme .-current flows through the arc,,..the are. products are-emitted in all directions from the areas oo- 1 cupied by the arc terminals they moveracross the sections of the arc runners. By mounting the sections of trap means 38 and 39 immediately adjacent the

arc runners

34 and 35 in the manner described, the rate of flow of are products into the space between the arc runners Where there is potential danger of reignition and restriking is controlled.

Although but one embodiment of the present invention has 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 desired to secure by Letters Patent: 4

1. An electric circuit interrupter comprising a pair of relatively movable cooperating arcing contacts, means for separating said contacts to initiate and elongate an arc therebetween, an arc chute for receiving the are at one end thereof, means for transferring the path of said are from the region of arc initiation to a region within said chute, trap means arranged substantially coextensive with said transfer means for reducing the free flow of products of arcing from said transfer means in the general direction of the are path, and flue means surrounding said transfer means and said trap means over substantially their entire length for exhausting to atmosphere the hot gases stripped in part of said products of arcing.

2. An electric circuit interrupter comprising a pair of relatively movable cooperating arcing contacts, means for separating said contacts to initiate and elongate an arc therebetween, an arc chute for receiving the are at one end thereof and exhausting the hot gases at the other end, are runners for transferring said are from the region of arc initiation to a region within said chute, trap means arranged adjacent the point of arc inception for reducing the free flow of products of arcing in the general direction of the arc path, and flue means surrounding said arc runners and said trap means over substantially their entire length for exhausting to atmosphere the hot gases stripped at least in part of said products of arcing.

3. An electric circuit interrupter comprising a pair of relatively movable cooperating arcing contacts, means for separating said contacts to initiate and elongate an arc therebetween, an arc chute for receiving the are at one end thereof and exhausting the hot gases at the other end, arc runners for transferring said are from the region of arc initiation to a region within said chute, trap means arranged in the region of initial arcing on said are runners for reducing the free flow of products of arcing i the general direction of the arc path, and flue means surrounding said are runners and said trap means over substantially their entire length for exhausting to atmosphere the hot gases stripped in part of said products of arcing.

4. An electric circuit interrupter comprising a pair of relatively movable cooperating arcing contacts, means for separating said contacts to initiate and elongate an arc therebetween, an arc chute for receiving the are at one end thereo fand eXhau'stingthe-hot gases attheother end, arc runners for transferring said are I from *the region of arc initiation toa --region -'-within said chute, -said-arc runners comprising a -first' section arranged substantially" perpendicularlyto I the direction ar-relative movement of said 'contacts and spaced 'from 'the region of arcinitiationanda second section arranged-angularly' With respect -to=said first section for transferring? one term-inal= ofsaid -arc-from -the-region of -are 1 ---initiation to "said i first section,*=trap means 'ar- 1 ranged adjacent the reg-ionwhere thearcis-being f elongated by said-second section of said arcrunners for reducing the free flow of products of arcing from said are runners in the general, direction of the arc path, and flue means sur-- rounding said are runners over substantially their entire length for exhausting to atmosphere the hot gases stripped in part of said products of arcing.

5. An electric circuit interrupter comprising a pair of relatively movable cooperating arcing contacts, means for separating said contact to initiate and elongate an arc therebetween, an. arc chute for receiving the are at one end therea of and exhausting the hot gases at the other end, a pair of diverging arc runners for elongat-- ing and transferring said are from the region of arc initiation into said chute, trap means ar-- ranged substantially coextensive with said diverging arc runners and adjacent the region Where the arc is introduced into said are chute: for reducing the free flow of products of arcing: from said arc runners in the general direction of the arc path, and flue means surrounding said are runners over substantially their entire length for exhausting to atmosphere the hot gases stripped in part of said products of arcing.

6. An electric circuit interrupter comprising a pair of relatively movable cooperating arcing contacts, means for separating said contacts to initiate and elongate an arc therebetween, an arc chute for receiving the arc at One end thereof and exhausting the hot gases at the other end comprising a plurality of insulating plates spaced a predetermined distance apart arranged to extend longitudinally of the axis of said chute, means for transferring the path of said are from the region of arc initiation into the arc receiving end of said chute, and flue means surrounding substantially the entire length of said transfer means for cooling and exhausting to atmosphere the products of arcing, said flue means having a greater cross sectional area than the cross sectional area of the space between adjacent insulating plates.

7. An electric circuit interrupter comprising a pair of relatively movable cooperating arcing contacts, means for separating said contacts to initiate and elongate an arc therebetween, an arc chute for receiving the are at one end thereof and exhausting the hot gases at the other end, an arc runner for transferring said are from the region of arc initiation to a region within said chute, and flue means within said chute defining a passageway surrounding said arc runner on all sides over substantially its entire length for cooling and exhausting to atmosphere the products of arcing emitted from said arcing contacts and arc runner.

8. An electric circuit interrupter comprising a pair of relatively movable cooperating arcing contacts, means for separating said contacts to initiate and elongate an arc therebetween, an arc chute for receiving the are at one end thereof, means for transferring the path of said are from the region of are initiation to a region within said chute, trap means arranged substantially coextensive with said transfer means for reducing the free flow of products of arcing from said transfer means in the general direction of the arc path, and flue means within said chute defining a passageway surrounding said transfer means on all sides over substantially its entire length for cooling and exhausting to atmosphere the products of arcing emitted from said arcing contacts and said transfer means.

' PHILIP L. TAYLOR.

- References Cited in the file of this patent UNITED STATES PATENTS Number 5 1,944,403 2,276,859 2,436,189