US2647184A - Time-delayed circuit breaker - Google Patents

Description

ly 1953 J. M. WALLACE r AL 2,647,134

TIME-DELAYED CIRCUIT BREAKER Filed May 16, 1950 2 Sheets-Sheet l I54 f I45 I 3 L 1f& |44 1 3 s I48 0 I60 no n2 n4 n1 |2 us 97 l4 0 46 Insulation 36 3e WITNESSES: 32 i INVENTORS 1 James M. Wol|uce8 6 BY Alfred R.McClung. 7%; gmwl WIN,

ATTORN EY y 23, 1953 J. M. WALLACE El AL 2,647,184

TIME-DELAYED CIRCUIT BREAKER Filed May 16 1950 -2 Sh eets-Sheet 2 Fi 2. w

INVENTORS James M. wollocea Alfred R. McClung.

WITNESSES:

$634M. Zw%w ATTORN EY B WZM Patented July 28, 1953 TIME-DELAYED CIRCUIT BREAKER James M. Wallace, East McKeesport, Pa., and Alfred E". McClung, Smithers, W. Va., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of- Pennsylvania Application May 16, 1950,. Serial No. 162,174

(argon-s9) 16 Claims. 1

This invention relates generallyto electric circuit breakers, and more particularly to such cirv cuit breakers having liquid time relay means for controlling breaker operations,

One difiiculty encountered with circuit breakers having liquid time delay means for controlling operationsthereof, is that gases formed by the action. of the arc during circuit interruption on the-arc extinguishing liquid, finds its way into. the. liquid delay means, such as a dashpot, and, thus undesirably alters the time characteristics thereof. This difficulty is, of course, accentuated when higher current values are interrupted, be-

cause such interruptions are accompanied by the. production of correspondingly greater amounts oi.

It is, therefore, an'obj'ect of the invention to provide a novel construction of hydraulically con-,. trolled circuit breaker wherein the gases. formed. during a circuit opening, operation, are. prevented from. interfering. with, the hydraulic control,

A more specific object; of this invention is .to, in a, hydraulically controlled circuit provide breaker, novel gas baffli'ngmeans for preventing,

gases formed during, a circuit opening operation.

from entering the hydraulic control system.

These and. other objects of this invention will become more apparentupon consideration ofvthe.

following detailed. description of a preferred embodiment thereof, whentaken. in connection with.

Fig. 2 isa partial enlarg'edlongitudinal sec,'

tional view of the lower part of the circuit breaker mechanism shown in Fi 1, and

. Fig. 3 isv a partial enlarged, view of the mech anism shown in Fig. l, with parts thereof being illustrated in section.

This invention is disclosed as being embodied" in a circuit-breaker of the type mounted in a.

container or metal tank, 2 having an open top. Preferably, a cylindrical liner 4 is provided for the side wall of tank 2, with a liner disk 6 being provided for the bottom of tank 2. The liners 4 and 6. are preferably of an insulating material, such for example, as fiber or the like. The top of tank 2 is adapted to be covered by a cover casting 8', which may be secured to the tank in any desired manner, such, for example, as by being bolted thereto (not shown). Cover casting 8' is adaptedflto support the circuit breaker mechanism and contacts by means of-a plurality of insulating supports In (only one shown) secured to'integral lugs I2 011 the cover casting, and. to a casting l4. Other insulating supports l6 are adapted to support a plate 18 from, casting H to mount a solenoid coil 20 therebetween. Still other insulating supports 22 are adapted to support the topcap 24 of an interrupter chamber 26 from cover 8.

The interrupter chamber 215 which is more clearly illustrated in Fig. zincludes a cylinder 28 of insulating material, such as fiber, having threaded ends, one of which is threaded into top cap 24, and the other end of which is threaded into a bottom cap 30. The bottom cap 30 of the interrupter chamber 26 has a centrally located tapped opening for receiving a contact supportingscrew 32 having a contact head 34 on the inner end. thereof, and adapted to have a nut 35 on, the outer end thereof for securing a conductor 38 thereto.

The conductor 38 leads from contact screw 32 to a conductor located in one terminal bushing 40 secured to cover casting 8, asby bolts 42. A movable contact rod 44 has the lower end thereof extending through a central opening in top cap 24 Ofj the interruptingchamber, and is provided, with a tubular sheath 46 of insulating material, such as fiber or a molded insulating material at. the point where it passes through top cap 24. The lower end of contact rod 44 has a contact head 48 threaded into a hole tapped in the lower end of contact rod 44, with the contact head having a contact tipv 50 secured thereto for engagement with the contact tip 34 on stationary contact screw 32 at the closed circuit position.

Within interrupting chamber 26 there is also provided a liquid directing structure mounted on the lower .end of contact rod 44, with this structure comprising a top plate 52 having a central opening slidablyreceiving the lower end of contact rod 44, and a nozzle plate 54 having a central opening somewhat larger than contact head 48., with these two plates being secured together by a plurality (only one shown) of connecting studs which are shouldered to maintain plates 52 and 54 in spaced relation, and are secured in place by screws 62. Each of the plates '52 and 54 are provided withnotches 56: and 58 respectively, cut in, their outer periphery, to permit relatively free passage of liquid at, the outer edgesof these plates. The liquid directing structure further in-,

downwardly by a coil compression spring 58 reacting between top plate 52 and contact rod 44, with this spring being in a compressed condition at the closed circuit position due to nozzle plate 54 engaging a stop ring 59 held in place between the lower end of cylinder 28 of the interrupting chamber and a shoulder on bottom cap 30. There is also a stop washer secured between contact head 40 and the lower end of contact rod 44, all for a purpose to be described.

Bottom cap of the interrupting chamber is provided with a plurality of inlet openings I2 adapted to be controlled by a check valve of ring 14 freely mounted for movement between bottom cap 3'9 and stop ring 69. The top cap 24 of the interrupting chamber is provided with a hollow chamber I6 having an opening at one side as at 10, and also communicating with the interior of the interrupting chamber as by outlet openings 80 provided in the inner wall of top cap 24. The outlet openings 80 are adapted to be controlled by a valve ring 82, preferably biased to a position away from openings 80 by a plurality of coil compression springs 84 (only one of which is shown).

The structure of interrupting chamber 26 and its operation is similar to that disclosed and claimed in the patent of J. M. Wallace, No. 2,528,197, which issued on October 31, 1950, entitled Circuit Interrupters, and is assigned to the same assignee as this invention. Accordingly, reference is hereby made to such copending application for a more detailed description of the construction and operation of this type of interrupting device. In general, when contact rod 44 is moved upwardly, an arc will be struck between the contact tips 34 and 50, and since the interrupting chamber is filled with an arc extinguishing liquid such as oil, being submerged in container 2 which is filled with such liquid up to level L, the arc will decompose the oil and generate gas within the interrupting chamber. This will cause an internal pressure which will seat valve rings I4 and 82 on the inlet and outlet openings, respectively. This internal pressure will also act on contact rod 44 and its sheath 46 in a pistonlike manner to accelerate its movement away from fixed contact tip 50. The liquid directing structure does not move during initial upward movement of contact rod 44 because it is held in engagement with stop ring 69 by spring 68. However, when contact rod 44 has moved upwardly an amount suflicient that stop washer 10 engages plate 52, the entire liquid directing structure will then be pulled upwardly with the contact rod, and liquid will be forced from the upper part of the interrupting chamber around the outer edge of plate 52 and through the central opening in nozzle plate 54 to provide a blast of liquid through the arc in a generally longitudinal direction. After contact rod 44 has moved upwardly an amount sufiicient to extinguish the arc, the pressure within interrupting chamber 26 will decrease and permit valve ring 82 to uncover outlet openings 80 and thus permit escape of gases from the interrupting chamber through outlet openings 80, hollow chamber I6, and openings I8 to be discharged at one side of the top cap 24 for the interrupting chamber. Gases which thus escape from the interrupting chamber are replaced by fresh liquid flowing into the bottom of the interrupting chamber through inlet opening 12 which displaces valve ring 14 upwardly. While the general structure and operation is thus very similar to that disclosed in the above-mentioned copending application of J. M. Wallace, it will be observed that one difference resides in the method of exhausting gases from the interrupting chamber due to the novel construction of top cap 24. In the case of an automatic reclosing circuit breaker which starts to reclose as soon as the circuit has been interrupted, the flushing out of gases and replacement of liquid within the interrupting chamber is facilitated during downward movement of contact rod 44 and the liquid directing structure by valve plate 64 which is free to move upwardly and thus uncover the openings around the outer edge of nozzle plate 54, so that the flushing operation is thus relatively unimpeded, as compared to the restricted path for flow of fluid through the liquid directing structure when the contacts separate.

'In order to automatically open the contacts in response to overloads on the circuit, it will be observed that the movable contact rod is connected by a conductor 86 to one terminal of solenoid coil 20 and this, in turn, is connected by a conductor 88 to the other terminal bushing 40 on cover casting 8 (not shown). The solenoid coil 20 is thus connected in series with the circuit through contact tips 34 and 50. A solenoid core 90 in the form of a tube is slidably mounted on contact rod 44, being of a magnetic material such as iron. The upper end of solenoid core 90 is slidably received in a collar 92 secured between supporting plate I8 and the bottom of the solenoid coil 20. The solenoid coil is annular in form and has a central opening receiving a dashpot sleeve 94 of insu lating material, such as fiber or a molded insulating material. An actuating tube 96 of a non-magnetic material such as brass or the like, has its lower end secured in the lower end of solenoid core 90 and it extends upwardly through solenoid coil 20 being provided with a collar 91 resting on the top surface of casting I4. A coil compression spring 98 is received within actuating tube 96 and reacts at its lower end against a collar 95 secured in the lower end of tube 96 and at its upper end engages an abutment (not shown) on contact rod 44.

Casting I4 is also of a hollow construction as seen in Figure 3, with the hollow chamber I00 formed within this casing communicating with the upper end of dashpot sleeve 94, and having an opening at one side which may be closed by a plug I02. However, if desired, plug I02 may be removed and the opening from chamber I00 will then be controlled by a piston valve member I 04 vertically slidably movable in a counting cylinder I06 mounted in casting I4. The lower end of counting cylinder I06 is closed by a. plug having an opening controlled by a ball-check valve I08 to permit liquid to enter the lower end of the cylinder but preventing it from escaping therefrom. Piston valve I04 is provided with a stem H0 at its upper end which has a plurality of annular ratchet flanges II 2 formed thereon in spaced relation, for engagement by a pawl II4 pivotally mounted as at I2I on a lever H6 having a split outer end located at opposite sides of contact rod 44, and resting on collar 91 of actuating sleeve 96. Lever H6 is pivotally mounted on casting I4 at I", and is normally biased counterclockwise to keep the outer end in engagement with collar 91 by a coil tension spring II8 secured between lever .6 and ailug' IIS'integraIWithcasting t4. Pawl H4 is biased. ina counterclockwise directionrelative: to lever H6" by a. spring I20;v tomaintain a nose I2'2- of theipawl in: engagement with the undersideof: lever H0.

,"-The particular construction of castingv I4 and parts associated therewith described above is similarto that disclosed; and: claimed inthe copending application of J. M. Wallaceet al., Serial" Nos. 719,524 filed December 31, 1946, on Circuit:

Interrupters, now Patent No; 2,626,329 issued January 20, 1953, and assigned tothe same assignee as this invention. Accordingly, for a more complete disclosure of. the constructionand operation thereof, reference is hereby made to. the

copending. application: of J. M. Wallace et al. Generally speaking, the" operation: of: interrupting the circuit, when. solenoid coil 2'0v becomes.

energized sufficiently to move core 901 upwardly,

isxthat. the core firstv moves upwardly displacing liquid in dashpot sleeve-94 upwardly into castingz'l4, and if plug M2 is in place the liquid can escape only by way of; the relatively small clearance' between core 98 and; collar 92 so that the upward movement of the core will thusbe slowed down by this dashpot action. However, if plug;

I02 is; not in place, the liquid will be freely dis:-

changed from chamber I: in casting I4, and.

solenoid core 90 will not be restrained in its. up-

ward movement, at least on a first circuit interrupting operation in any series of. closely successive circuit interruptin operations. Upward. movement of core 90:, of course, carries actuating. sleeve: 96 and its collar 01 upwardly, and this moves lever IIG upwardly to carry pawl 4* into engagement with the uppermost. ratchet flange M2 on piston I04 to carry the piston upwardly a: predetermined amount. Upward movement of: core 90 also will ultimately compress: spring 98 sufiiciently to cause upwar'dimovem'entof contactrod 44, to thus establish anarc and'interrupt the circuit in the manner previously described.-

After a circuit interruption; core 90 and contact rod 44 are free todescendtogether to close thev circuit, except that, if plug I02: of casting [i4 is in place, this. descent will be. slowed down by the necessity of replacing liquidi within the upper part'of dashpot sleeve 94 through the relatively small clearance between the core 90 and collar 9 2. If upon reclosing of the circuit breaker. con tacts the overload still persists the contacts will.

immediately be reopened in the same manner except that this time counting piston I04 will. be advanced a further amount to a position where:

it closes the opening from chamber I00, so that thesecond. closin operation will be slowed: down by the dashpot action of core 901 in sleeve": 94-,even. though plug is not in place.- On; a third closely successive circuit opening operation: the upward movement of core 90- will be slowed down by the dashpot action of sleeve 9I4, even: though plug M2 isnot in place, because piston; valve I04 will still be at a position, where it closes oft the opening from chamber I00 ofcasting I4. While piston I 04 is biased by gravity to reset to its orig inal position, this action is very slow dueto the. necessity of displacing liquid trapped beneath the piston through the relatively small clearance 1 between the-piston and cylinder I 06, with the re sult that piston I04 does not have time to reset:

where circuit interrupting operations occur rapid succession.

, The upper end of contact rod: 44: is connected by a pair of insulating links I124, 013. fiber or thelike; to the commonipivot IEZB of a pair of links I-IBJ and I Link I30: is biasedztoa theyleft as viewed in;Fig. 1 by a. coil tension spring l'32 connecting" link r30 and cover casting:8. However;

since; link. I2 8,: which is of inverted channel form: having side flanges I: (only one of which is shown), has its other: end. pivoted on a. bracket.- Iz3.6. supported from cover casting 81 as by screws" I'3-8,. and since. link: I.30.has an integral. hook I34 which; extends: through an opening: in" the bight portion: of: link I2 8, the result: is. thatspring I32 biases. link I28 in a clockwise direction, to thus bias contactrod 44 downwardlyto exert pressure:

causing: pressure engagement of contact tips 50. and 34.

There is also provided within cover casting 8- apai'r'of' togglelevers I40 and M2 connected by" Toggle lever I42 has its. other end slotted to receive a fixed pin I40 a center pivot I44.

mounted in cover casting 8, while toggle lever I40: is mounted on a: fixed pivot I46 and extends outthrough an opening in the cover casting" beneath a hood portion I to forma handle extension. I52 having a hook-eye I56 in the outer end thereof for manual operation. A coil com pression spring I istelescoped over toggle lever I42 thus pushing this lever and center pivot I44 H. L. Rawlins et al., Serial No. 719,572, filed 1061- cember 3.1, 1946,. on Circuit Interrupters, now Patent No. 2,622,167 issued December 16, -2, and assigned to the. same assigneeas this invention. Accordihgly,'for a'more' complete description of the structure and operation of these parts, reference is hereby made to the Ra-wlins et a l. application. In general, the operation of theseparts during a circuit opening operation is such that initial upward movement of contact rod 44 during a circuit opening operation results in levers I28 and I30 approaching each other to-thus reducethe force component of spring I32 which biases contact rod 44 downwardly; until the end of spring I32 connected to lever I30 substantially coincides. with the pivot mounting of lever" I 28 on bracket I 36 At this time, spring I32 will have substantially no force component in a downward direction, and accordingly, contact rod 44' is not opposed by spring I32 in its further upward movement; It will be apparent that whenthe circuit is interrupted, thus freeing" contact rod 44 for downward movement whichmay or may'not be impeded by the dashpot action of solenoid core 00 indashpot sleeve 94 as previously pointed out, that the parts will move downward'initially due to the force of gravity", until the. point is reached where links I 28 and I30 begin to separate, and thus establish a downward component. of spring I 32, to accordingly increase the: speed at which final engagement of the contactsv occurs and, of course, finally establislm a contact pressure; as previously pointed out.

Handle extension I52 of toggle: lever I40 may, of. course. be moved downwardly to move center pivot I44 upwardly oyercenter, to. thus release spring I50. The center pivot pin I44 has an extension beneath the adjacent flange I35 of link I28; so that: upward movement of this center: pin carries link I28, it, and consequently,

raises contact rod 44 to open the circuit breaker contacts. Such manual opening of the circuit breaker contacts is, of course, accelerated by spring I50 as soon as pivot I44 passes overcenter, and the circuit breaker contacts are maintained open by spring I59. After such a manual operation the circuit breaker may be manually closed by moving handle extension I52 upwardly, and thus permitting contact rod 44 to move downwardly in the manner previously described.

Toggle lever I42 is provided with an extension I58 which overlies an extension I60 of insulating material, such as fiber or a molded insulating material, mounted on the upper end of stem IIG of piston I84. The purpose of this is to lock the circuit breaker contacts open after a predetermined number of closely successive circuit interrupting operations have occurred. Thus, as previously pointed out, piston I04 will be advanced a predetermined amount on each circuit opening operation, and if these operations occur in close succession, the piston will eventually be advanced an amount sufficient to cause its extension I55! to engage extension I58 of toggle lever I42, and move pivot I44 overcenter, to thus cause opening of the contacts by spring I50 in the manner previously described, and this spring, of course, will then hold the contacts at an open circuit position.

It will be observed that both circuit opening and circuit closing operations may be controlled by the dashpot action of solenoid core at in dashpot sleeve 94, with this operation during a circuit interruption displacing liquid trapped in the upper part of dashpot sleeve 94 out through the narrow clearance between core Eli] and collar 82. During a circuit closing operation, the reverse flow of fluid occurs, because fluid must then be supplied to the upper part of dashpot sleeve 84 through the same narrow clearance. In prior devices Where the gases evolved during a circuit interrupting operation were released at a point beneath dashpot sleeve 94, such gases in passing upwardly in container 2 often found their way into dashpot sleeve 34 thus causing erratic operation thereof both in circuit opening and circuit closing operations. It will be observed that this can not happen with the construction comprising this invention, because the gases generated during circuit interruption are released at one side, through side opening 18 from chamber 16 in top cap 24 of the interrupting chamber 26, so that in proceeding upwardly'these gases will follow a path laterally spaced from the lower end of dashpot sleeve 94. Moreover, top cap 24 of the interrupter chamber is formed to provide a gas baffle or separator which prevents escape of gases to the top of cap 24 through the clearance between sleeve 46 and the central opening in cap 24. This is due to the fact that sleeve 48 passes through two Walls of top cap 24, and that chamber 16 is formed between these two walls. Thus, while a high pressure may exist within the chamber during circuit interruption which may force gas through the clearance between sleeve 46 and the central opening of the inner wall of top cap 24, this gas arrives in chamber 16, and there being no pressure differential between this chamber and the top side of cap 24, but actually chamber 16 being liberally vented at opening 18, gas arriving in the chamber will be free to move laterally through it and escape from this side opening 18 which provides an effective gas directing means. Thus, no gas will appear above the top of cover cap 24, and to make sure that gas bubbling upwardly from side opening 18 does not deviate inwardly, a tubular shield I82 of insulating material, preferably a molded insulating material, is placed immediately above top cap 24, being supported from supporting plate I8 by means of brackets I64 which may be welded thereto and secured to shield I62 as by screws I66. Gases escaping from interrupting chamber 26 are thus at all times prevented from reaching the dashpot liquid inlet or intake at the lower ends of dashpot sleeve 94 and collar 92, so that no improper operation of the dashpot can result. Conductor 86 extends through a vertical slot 81 in shield I62 at the side opposite gas outlet 18.

An additional precaution is taken where the dashpot action during a circuit closing operation is made to be different than that during a. circuit opening operation, as illustrated in Fig. 3, by the provision of an additional inlet for fluid into the upper part of dashpot sleeve 94 during descent of core 90. This is provided in the underside of casting I4 which has a tapped opening for threadedly receiving a plug I68 which is hollow and has a small opening extending through an intake extension I12 of reduced area, and controlled by a ball-check valve I10. The plug I 68 has an integral relatively large sleeve I14 which is closed at its lower end by a closure disk I16 to form a sump chamber having an inlet from the interior of tank 2 formed by a slot I18 at the top of this sump chamber. During a circuit closing operation, ball-check valve I10 will be unseated to permit additional fiow of liquid inwardly through the plug I68, and if there is any gas in the vicinity of the intake, there will be no tendency for it to accumulate at the bottom of the sump because the rate of oil flow into chamber I00 of casting I4 is small compared to the size of the sump, and, consequently, a supply of clear oil is maintained under check valve I10, and any gas bubbles in container 2 will rise past slot I18, there being no tendency for them to enter the sump formed in the bottom of plug I68.

It is believed apparent from the foregoing that this invention provides an arrangement for circuit breakers which have one or more of their operations controlled by liquid time delay means, such as a dashpot, whereby gases formed by action of the are on the liquid employed in the circuit breaker, are positively prevented from interfering with the operation of such time delay means. Important features of this construction comprise confining the escape of such gases to a position at one side of the circuit breaker at a point laterally displaced from the liquid intake of the time delay means, and the provision of baflies to prevent such gases from affecting the time delay means.

Having described a preferred embodiment of the invention, in accordance with the patent statutes, it is desired that the invention be not limited to the particular constructions described herein, inasmuch as it will be apparent to persons skilled in the art that many changes and modifications may be made in these particular constructions without departing from the broad spirit and scope of the invention. Thus, it is apparent that the invention need not be employed with circuit breakers of the automatic reclosing type although it has certain novel features of cooperation with this type of circuit breaker, but may be employed in any type of circuit breaker having one or more operations there- 9 of'controlled by liquid time delay means. Also, the-gas separating means herein disclosed may be employed sepa tely or in various combinatlonsthereof. Accordingly, it is desired that the invention be interpreted as broadly as possible and be limited only as required by thepror art.

We claim as our invention:

l-.*A'-circuit breaker comprising, a container 3 for an arc extinguihing' liquid, separable contacts mounted in said container beneath the liquid level thereof, means responsive to a'predeterfl mined condition of the circuit for separating said contacts to interrupt the circuit, liquid time delay means controlling the operation of said, condition responsive means'and also located in said container, said timed'elay means having a liquid inlet positioned below the liquid level in saidcontainer so that it: will employ said are extinguishing liquid in operation, and gaspbafll'e means in said container below the" liquid level thereof for preventing gases generated by the arc formed during separation. of said contacts iromentering the liquid inlet of said time delay means. 1

"2. A circuit breaker comprising, a. container for an arc extinguishing liquid, separable contacts mounted in said container beneath the liquid level thereof, means'responsiveto a predetermined condition of the circuit for separating said contacts to interrupt the circuit, liquid time delay means controlling the operation of said: condition responsive means and also located in said container, said time delay means having a liquid inlet positioned below the liquid level in said container so thatit'will employ said are; extinguishing liquid in operation, and gas baflle means in said container below the liquid level thereof and positioned adjacent said liquid inlet; for preventing gases generated by the are formed during separation of said contacts from entering the liquid inlet of said time delay means.

3. A circuit breaker comprising, a containeri'or an arc extinguishig liquid, separable contacts mounted in an arc chamber located within said container beneath the liquid level thereof, means responsive to a, predetermined condition ofthe' circuit for separating said contacts to interrupt;

the circuit, liquid time delay means controlling the operation of said condition responsive means and also located insaid container, said'jtlme delaymeans having a,- liquid inlet positioned below the liquid level in said container so ,thatit will employ said are extinguishing liquid in operation, saidchamber having an outlet" for" gasesgenerated bythe arc during acircuit opening operation, and gas directing means disposed adjacent to said gas outlet for directing the escaping gases away from theliquld inlet of said time delay means for preventing gases generated by the are formed during, separation of said eon-- tacts afrom entering the liquid inlet of said time; delay means. I

4'. A lcircuit breakercomprlsing, a container for an arc extinguishing liquid, separable-con tacts mounted in an arc chamber located within said container beneath the liquid levelthereof, means; responsive to. a predetermined condition of. the: circuit for separating said contacts to interrupt the circuit, liquid time delay means controlling the operation of said condition responsive means andalsolocated in saidcontainen said time delay meanshaving a liquid inlet positioned below the liquid level in said container so that it will employ said, arcjextlnguishing liquid in operation, said arc chamber having an outlet for gases generated by the arc duirng a circuit opening operation, gas directing means disposed adjacent to said gas outlet for directing the escaping gases away'irom the liquid inlet of said time delay means, and gas bai'rle means in said container below the liquid level thereof for preventing gases generated by the arc formed during separation of said contacts from entering the liquid inlet of said time delay means.

'5. A circuit breaker comprising, a container for an arc extinguishing liquid, separable contacts mounted in said container beneath the liquid level thereof, means responsive to a predetermined condition of the circuit for separating said contacts to interrupt the circuit, liquid time delay means controlling the operation of said condition responsive means and also located in said container, said time delay means having a liquid inlet positionedbelow the liquid level in said container but above said contacts so that it will employ said are extinguishing liquid in operation, and inlet opening to the interior of said container at one side for preventing gases generated by the are formed during separation of said contacts from entering the liquid inlet of said time delay means.

6. A circuit breaker comprising, a container for an arc extinguishing liquid, separable contacts mounted in an arc chamber located within said container-beneath the liquid level thereof, means responsive to a predetermined condition of the circiut for separating said contacts tointerrupt the circuit, liquid time delay means controlling theoperation of said condition responsive means andalso located in sai-dcontainer, said time delay means having a liquid inlet positioned below the liquid level insaid container but above said contacts so that it will employ said are extinguishing liquid in operation, said are chamber having an outlet at one side for gases generated by the arc during" a, circuit opening operation for preventing gases generated bythe are formed during separation of said contacts from entering theliquid inlet of said time delay means.

7. A circuit breaker comprising, a container for an arc extinguishing liquid, separable con-- tacts mounted'in an arc chamber located within said container beneath the liquid level thereof, means responsive to a predetermined condition of the circuit for separating said contacts .to

said are chamber having anoutlet at one side for gases generated by the arc during a circuit opening, operation, and. said inlet opening to the interior of saidcontainer atone side for preventing ases generated by the are formed. during sep aration of said contacts vfrom. entering the liquid inlet otsaid time delay means.

'8. An automatic reclosing circuit breaker coniprising;,a.container for an arc extinguishing liquid,separabiecontacts-mounted in said container beneath the liquid level thereof, means respon- -sl ve to a. predetermined condition ofv the circuit for separating said contacts to interrupt the: circult, meansvresponsiveto a circuit. interrupting operation to automatically close. the contacts, liq;- uid time delay means in said container operable inopposlte directions to controlaopening andclosing of said contacts, said time delay means having a liquid inlet positioned below the liquid level in said container so that it will employ said arc extinguishing liquid in operation, and gas bafiie means in said container below the liquid level thereof for preventing gases generated by the are formed during separation of said contacts from entering the liquid inlet of said time delay means.

9. An automatic reclosing circuit breaker comprising, a container for an arc extinguishing liquid, separable contacts mounted in said container beneath the liquid level thereof, means responsive to a predetermined condition of the circuit for separating said contacts to interrupt the circuit, means responsive to a circuit interrupting operation to automatically close the contacts, liquid time delay means in said container operable in opposite directions to control opening and closing of said contacts, said time delay means having vent means through which liquid is expelled during a circuit opening operation and istaken in during a circuit closing operation, an arc chamber for said contacts which is closed at' least during a circuit interrupting operation, means for venting said chamber duringa circuit closing operation and gas baiiie means in said container below the liquid level thereof for preventing gases vented from said arc chamber from entering the liquid inlet of said time delay means 10. A circuit breaker comprising, a container for an arc extinguishing liquid, an arc chamber mounted in said container below the liquid level therein, separable contacts mounted in said chamber which are actuated by a rod passing through an opening in the top wall of said chamber, liquid time delay means for said rod disposed above said chamber and having a liquid inlet below the liquid level in the container so as to employ said are extinguishing liquid in operation, the top wall of said chamber being hollow at the point where the opening for said rod is located, and a side opening communicating between said hollow space and the interior of the container to prevent gases formed during a circuit opening operation from travelling up along the rod and entering the inlet of said time delay means, v 11., A circuit breaker comprising a container for an arc extinguishig liquid, an arc chamber mounted in said container below the liquid level therein, separable contacts mounted in said chamber which are actuated by a rod passing 1 through an opening in the top wall of said cham- I said chamber being hollow at the point where the opening for said rod is located, a side opening communicating said hollow space with the interior of the container to prevent gases formed during a circuit opening operation from travelling up along the rod and entering the inlet of said time delay means, and a cylindrical gas baiiie about said rod and liquid inlet above said chamber and at a lateral distance from the rod which is less than the distance of saidside opening from said rod, to thus prevent gases emanating from said opening from working inwardly toward the rod and inlet of the time delay means.

12. A circuit breaker comprising, a container for an arc extinguishing liquid, an arc chamber mounted in said container below the liquid level therein, separable contacts mounted in said chamber which ar actuated by a rod passing through an opening in the top wall of said chamber, liquid time delay means operable to delay movement of said rod disposed above said chamber and having aliquid inlet below the liquid level in the container 50 as to employ said are extinguishing liquid in operation, the top wall of said chamber having a hollow space at the point where the opening for said rod is located, a side opening communicating said hollow space with the interior of the container to prevent gases formed during a circuit opening operation from travelling up along the rod and entering the inlet of said time delay means, and means for venting said chamber to said hollow space after a cir cuit opening operation.

13. A circuit breaker comprising, a container for an arc extinguishing liquid, an arc chamber mounted in said container below the liquid level therein, separable contacts mounted in said chamber which are actuated by a rod passing through an opening in the top wall of said chamber, liquid time delay means operable to delay movement of said rod disposed above said chamber and having a liquid inlet below the liquid level in the container so as to employ said are extinguishing liquid in operation, a side opening in said chamber for the escape of gases therefrom formed therein during a circuit opening operation, and a cylindrical gas bafile about said rod and liquid inlet above said chamber and at a lateral distance from the rod which is less than the distance of said side opening from said rod, to thus prevent gases emanating from said opening from working inwardly toward the rod and inlet of the time delay means.

14. A circuit breaker comprising, a container for an arc extinguishing liquid, separable contacts mounted in an arc chamber located in the container beneath the liquid level thereof, means responsive to a predetermined condition of a circuit for separating said contacts to interrupt the circuit, liquid time delay means controlling the operation of said condition responsive means and also located in said container, said time delay means having a liquid inlet positioned below the liquid level in said container but above said contacts,and a chamber substantially enclosing said inlet to shield it from gases generated by an arc during contact separation, said chamber having,

an opening in one side to admit liquid to said chamber for supplying said inlet.

15. In a circuit interrupter, a container for an arc extinguishing liquid, separable contacts disposed in said container beneath the liquid level thereof, means responsive to a predetermined condition of a circuit for separating saidcontacts to interrupt the circuit, liquid time delay means controlling operation of said condition responsive means located in said container and havinga liquid inlet positioned below the liquid level, and a sump chamber for maintaining a;

supply of the liquid for said inlet, said chamber substantially enclosing said inlet and having a relatively narrow opening on one side for ad- 'mitting liquid. 16. A circuit breaker comprising, a container.

for an arc extinguishing liquid, separable contacts disposed in an arc chamber located within.

sive meanslocated in said container and having a plurality of liquid inlets, one of said inlets being disposed substantially centrally of and above the arc chamber, said are chamber having an outlet at one side for gases generated by an arc during a circuit opening operation, and means providing a chamber about another of said openings, said chamber having a side wall with a relatively narrow opening therein for the liquid.

JAMES M. WALLACE.

ALFRED R. MCCLUNG.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Wallace June 20, 1944 Kyle, Jr., et a1 Nov. 30, 1948 Matthews Nov. 1, 1949 Wallace Oct. 31, 1950 Hubbard Sept. 18, 1951

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