US2568470A - Progressive arc quencher - Google Patents

Description

Sept. 18, 1951 Q ns 2,568,470

PROGRESSIVE ARC QUENCHER Filed Dec. 29, 1949 2 Sheets-Sheet 1 1 v Inventor:

Charles liTibus,

by W

His Attorney.

Sept. 18, 1951 c n'us 2,568,470

PROGRESSIVE ARC QUENCHER Filed Dec. 29, 1949 2 Sheets-Sheet 2 V 7%- M: :/A// V 59" A Fig.4.

Inventor: Charfles f-LTious, b His Attorney.

Patented Sept. 18, 1951 Charles H. Tit-us, Philadelphia, Pa, assignor to General Electric Company, a corporation of New York AppIicationDecember 29, 1949,SerialN 0.1351596 1 claim. (Cl. 200''144) The invention relates to are 'quen'chers, particularly arc quenchers for operation in connection with the arcing contacts 'of 'heavy duty-circuit interrupters.

The principal object is to provide an improved progressive type of heavy-duty arc quencher having relatively movable slotted and 'landed arc-quenching membersone of which is-operable with a circuit-interrupting arcing contact for drawing the arc progressively through restricted and enlarged spaces between the members so that the ionized gases "sustaining the are are progressively brought into intimate contact "with the lands of the arc-quenching members in the restricted spaces and expanded in the enlarged slotted spaces and thereby rapidly become reduced in temperature and thus de-ionized to extinguish the are.

A further object is toenable a movable arcing contact mechanically to carry the are along a narrow extended path between closely adjacent arc-quenching members of insulating material that are relatively movable and provided with opposing series of progressively registering slots and lands for, in effect, grinding and quenching the arc therebetween to induce turbulence and pressure drop in the arc-sustaining gases and thereby expedite the arc-quenching action.

Another object is to provide an improved rotary type of arc quencher structure having a rotatable arcing contact and progressively registering concentric series f relatively rotatable slots and lands for rolling and quenching the arc gases therebetween within a relatively small quadrantal space.

Further objects and advantages of the invention will appear in the iollowing description of the accompanying drawings wherein Fig. 1 .is a side view of a heavy-duty circuitinterrupter provided with a rotatably mounted arcing "contact combined with-an improvedrot'ary arc quencher embodying the improvements of the present invention with the circuit interrupter shown in the closed position; Fig.2 is a similar view showing the relative position of the parts when the circuit interrupter is opened and the are quenched; Fig. 3 is a partial sectional 'v-iew along the-dash line 33 of Fig. -1 showing the details of construction of :the relatively ro'tatable arcquenching members; Fig. 4 is a side view of a modified form of circuit interrupter provided with an arcing contact movable in 'alinear path and combined with an arc quencher having pro- 'gressively registering linear series of slots and lands for quenching the arc therebetween 'in g accordance with the present invention.

As shown in 'Fig. 1, the "heavy-duty circuit finterrupter indicated generally by the reference character 'la is of the improved rotary arcing contact take-up type more fully described -and {60 claimed in the copending application, Serial No. 135,796, filed December "29, 1949, by John A. Favre, and assigned to the 'assignee of the present invention. The circuit interrupter I0 is provided with a pair of main current-carrying contacts H and [2 that are connected respectively to the terminals [3 and I4 and also respectively to a pair of spaced-apart stationary arcing contacts Iii-that are aligned one behind the other as shown in Fig. 1. "One of the spaced-apart stationary arcing "con't'actslii is connected through conductors l6 and l'! with the terminal 13 while the other contact [5 is connected through condoctors?!) and 2| with the terminal 14.

As more fully described and claimed in the Fav're application, the rotatably mounted bridging contact '22 for engaging and disengaging the pair of 'spaced apart stationary arcing contacts 15 is carried on a contact wear take-up arm 23 that is 'pivotally mounted 'on pin 24 which 'in turn is carried on the rotatable "base plate 25. The base plate 25' is pivotally mounted on the stationary pin 26 by means of the yoke 27.

improved sequential "contact-operating mechanism, :also more fully "described and claimed in the Favre application, and indicated generally by the reference character 39 is provided with a main operating push-pull rod 31 that is guided in a linear path between the concave rollers 32 and 33 'andhas a link 34 pivoted on ,pin 35 carrying roller 35 and guided by the roller mounting pin 31 engaging with the slot"38 formed in the stationary guide member 39 for movingroller 36 into engagement 'with movable main contact 12 to force-contact l2 intowiping circuit-closing engagement with the cooperating main contact 'I l against the strain of their re spective biasing springs 43 and 44. The hooked member 45 is secured to contact l2 for engagement by pin '3"! to enforce the opening of the main contact 1 2 when rod 3! is moved in the opposite "direction.

The-main operating rod 31 also carries a link 46 pivoted 'at-one end on pin 4"! with the other end connected to the knee of the togg'le link-s 48 and 4 9 that are pivoted respectively-on the stationary pin 50 and the pin 5| carried by the pivotally mounted arm 23 so as to sequentially rotate the bridging contact 2 2 out of engagement with the pair of spaced-apart stationary arcing contacts l5 after thesep'aration of the main contacts H and 12 :is completed. The disengagement-of the rotatable bridging-contact z-iefiects the .final interruption of the circuit .and draws larcs between the bridging contact 2-2 and the spaced-apart stationary arcing -.c0ntacts l5. 7

V In accordance with the present invention, the arcs :are quickly extinguished by the improved rotary type of progressive arc quencher-shown in "Figs. -1 iand 2 having relatively rotatable -completnntary' nested arid concentric cylindrical arcquenching members 55 and 56 formed of suitable insulating materials such as molded phosphoe asbestos to provide the several series of slots 51, 58, 59 and 60 and a corresponding series of lands 6|, 62, 63 and 64 for quenching the arcs therel5 with the circuit breaker H) in its closed'posi tion. The series of slots 58 and lands 62 likewise are located in opposing concentric alignment on the other side of the bridging contact 22 and the arcing contacts I5 so as to effect progressive registration of the lands in each series with the slots and lands of the opposite series upon opening of the circuit breaker in order to quench the arc therebetween.

The stationary arc-quenching member 55 may be formed of an assemblage of a concave arcuate insulating block provided with the series of slots 51 and lands 61, and a concave arcuate insulating block H provided with the series of slots 58 and the lands 62. The blocks 10 and II have suitable slots or openings for embedding the spaced-apart arcing contacts l5 therebetween with the face of the arcing contracts in substantial alignment with the convex concentric cylindrical series of lands 6! and 62 of the blocks as indicated in Fig. 3. The blocks 70 and H are respectively further provided with deep central arcuate grooves 12 and 13 extending in alignment midway between the spaced-apart arcing contacts 15 as shown more clearly in the partial sectional view of Fig. 3.

The rotatably mounted complementary nesting convex arcing member 56 is of substantially semicylindrical form with suitable provision made for embedding the bridging contact 22 within a recess or tunnel '15 formed therein for receiving the U-shaped bridging member 22 therein while permitting free substantially radial movement of the bridging contact 22 when the arm 23 on which the bridging member 22 is mounted is rotated about the pin 24. The rotating arc-quenching member 55 is suitably secured to the mounting plate 25 so as to rotate about the pin 26 as an axis and thereby maintain relatively close running clearance between the series of lands 63 and 64 formed thereon and the opposing concentric cylindrical series of lands 61 and 62. The rotatably mounted arc-quenching member 56 is provided with a central arcuateshaped vane 14 that extends into a freelyrunning fit with the arcuate concentrically aligned grooves 12 and 13 so as to provide a continuously effective insulating barrier between the two spaced-apart arcing contacts 15 during the relative rotary motion of the movable arcingmember 55 with respect to the stationary arcing member 55 formed by the two concave blocks 16 and IL Operation Referring to Fig. 1, when the operating rod'3l is lowered by suitable automatic overload current-responsive means, not shown, the main contacts II and 12 are separated by operation of the link 34 and'roller 31 with the hooked member serving to apply a positive force in addition to the opening bias of springs 43 to effect the separation. The separation of the main contacts I l and I2 shunts the-current through the spaced-apart 4 arcing contacts 15 and the bridging contact 22 Upon the rapid sequential separation of the bridging contact 22 from the spaced-apart arcing contacts I5 by operation of link 46 to buckle the toggle links 48 and 49, arm 23 is rotated about pin 24 to withdraw the bridging contact 22 sub stantially radially within the recess or tunnel 15.

At the same time the mounting plate 25 is rotated about pin 26 to carry the semicylindrical arcing member 56 along with the bridging contact 22 so as to mechanically draw the arcs formed between the bridging contact 22 and the stationary arcing contacts [5 along a narrow path extending between the closely adjacent nesting cylindrical arc- quenching members 55 and 56. In this way, the opposing series of lands 63 and 64 on ,the movable arc-quenching member 56 are progressively brought into register with the slots 5'! and 58 and lands 6| and 62 to quench the arcs therebetween upon rotary movement of the pivotally mounted arc-quenching member 56 and bridging contact 22. As a result, the ionized gases sustaining the arcs are brought into intimate contact with the lands of the relatively movable arc-quenching members when the lands register and expand in the slots between the lands when the slots register so as to induce turbulence and pressure drop in the arc-sustaining gases and thereby expedite the arc-quenching action to extinguish the arc before the parts reach their relative position shown in Fig. 2.

During the quenching of the arc between the progressively registering lands and slots of the relatively movable arc-quenching members 55 and 56, the arcuate barrier 14 that runs in the aligned arcuate slots 1'2 and 13 serves to effectively separate the arcs drawn at the opposite ends of the U-shaped bridging member 22 so that the hot gases sustaining each are are forced into intimate turbulent engagement with the relatively movable slots and lands on either side of the control barrier 14 to become rapidly cooled, thereby increase the arc resistance at each restricted section and extinguish each arc in a relatively small quadrantal space. The slots between the lands provide for venting the arc gases laterally therethrough and suitable barrier plates, not shown, may be spaced apart on each side of the relatively movable arc- quenching members 55 and 56 in the path of the vented gases. The rapidly expanding gases are cooled and rapidly deionized in order to increase the dielectric strength of the gas. The increased dielectric strength permits a higher steady state and transient recovery voltage to be interrupted.

In the modified form of circuit interrupter, shown in Fig. 4, the push-pull operating rod carries a bridging contact 8| in a linear path for engaging between the relatively stationary contacts 82 and 83. However, the contact 82 is pivotally mounted upon the terminal 84 by means of the conducting pin 35 and is biased into engagement with the bridging contact 8! by spring 86. Likewise, contact 83 is pivotally mounted on the terminal 8'l'by means of the conducting pin 85 and is biased to engage the bridging contact 8| by the spring 89.

In order to quench the arcs drawn upon separation of the bridging contact 8| from the pair of relatively stationary contacts 62 and 83 in accordance with the present invention, two rows of insulating plates 94 and 95, formed of suitablevarc resistant insulating material, are

mounted between the front and back plates 56 and 91, also formed of insulating material, in parallel spaced alignment adjacent the linear path of the bridging contact BI and in predetermined linear alignment with the respective contacts 82 and 83 to provide alternate series of lands 98 and 99 and slots I and IN on opposite sides of the linear path of bridging contact 8Iv The bridging contact 8| carries for movement therewith an insulating member I04 having the series of slots I05 and I05a formed on the opposite sides thereof to provide a corresponding series of lands I06 and I0! for progressively registering with the opposing alternate series of lands 98 and 99 and slots I00 and IOI to quench the arcs therebetween in substantially the same Way as the progressively registering slots and lands of the rotary type of circuit interrupter previously described. Thus, the ionized gases sustaining the are drawn between the bridging contact 8| and the cooperating contact 82 prior to interruption of the circuit are progressively brought into intimate contact with the series of lands 98 and I08 causing the arc resistance to rise over the restricted sections upon the progressive registration thereof and are expanded in the enlarged spaces provided upon the progressive registration of the series of slots I00 and I05 and thereby rapidly become reduced in temperature and thus deionized to extinguish the arc. Exactly the same arc-quenching is provided by the progressively registering series of lands 99 and I0! and progressively registering series of slots IOI and I06 to quench the arc drawn between the bridging contact BI and the cooperating contact 83. The alternate registration of the lands and slots induces turbulence and pressure drop in the arcsustaining gases and thereby expedites the arcquenching action by virtue of forcing the ar into a series of restricted, high resistance, $1101 a arcs having intervening sections which are rapidly deionized by quickly cooled gases which are then capable of withstanding high recovery voltages of a transient and a steady state nature.

III

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

In combination, a concave arcuate arc-quenching member provided with a series of alternate slots and lands transverse the concave arcuate face thereof and having an arcuate slot formed circumferentially therein, a pair of axially spaced-apart arcing contacts embedded in the concave member with the ends of the contacts in substantial alignment with the lands on opposite sides of the arcuate slot, a convex arcuate arc-quenching member rotatably mounted in nesting relation with the concave member and provided with a series of alternate slots and lands transverse the convex face thereof and having a bridging contact movable therewith for engagement with the spaced-apart arcing contacts, and means for rotating the convex member to disengage the bridging contact and draw arcs between the bridging contact and spaced-apart arcing contacts and progressively register the slots and lands of the rotatable convex arcquenching member with the slots and lands of the concave insulating member to quench the arc therebetween, and having an arcuate barrier extending centrally therefrom into the arcuate slot formed in the concave member for separating the arcs.

CHARLES H. TI'IUS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,199,607 Bakken May 7, 1940 2,315,618 Hufistutter Apr. 6, 1943 2,416,185 Leeds Feb. 18, 1947 2,452,477 Leeds Oct. 26, 1948

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