US2468851A - Reclosing circuit interrupter - Google Patents

Description

INVENTOR 2 Sheets-Sheet 1 "'IIIIII In!!! J. M. WALLACE RECLO SING CIRCUIT INTERRUPTER May 3, 1949.

Filed Jan. '7, 1944 16 w :56 zna im/M BY? J ATTORN 251/ I ay/4%.

\ B Q1. 3" I. ATTORN May 3, 1949.

J. M. WALLACE 2,468,851

RECLOSING CIRCUIT INTERRUPTER Filed Jan. 7, 1944 2 Sheets'Sheet Z WITNESSES: INVENTOR Patented May 3, 1949 RECLOSING CIRCUIT INTERRUPTER James M. Wallace, Braddock, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application January 7, 1944, Serial No. 517,327

19 Claims. (Cl. 175-294) This invention relates to reclosing circuit interrupters in general, and more particularly to means for providing closely successive circuit interrupting operations of an automatic reclosing circuit breaker with diiferent time characteristics.

Although of general application, this invention. is disclosed herein as applied to so-called pole-top breakers which have all of the parts thereof enclosed in a relatively small casing suitable for mounting on a pole or cross arm, wherein it has certain particular novel features of cooperation. Although breakers of this type are made with some time delay on each circuit interrupting operation, it is highly desirable that they operate to interrupt the circuit with different time delay periods on continuing faults where the breaker automatically goes through a plurality of closely successive circuit opening and recloslng operations, and after a predetermined number of such operations is automatically locked in open circuit condition. Use of a relatively great time delay, preferably on the second circuit opening, will permit selfclearing faults to burn clear prior to lockout of the breaker. Furthermore, it is desirable that at least one opening of the breaker have thermal inverse time-current characteristics to properly coordinate with fuses and other apparatus having like characteristics.

Accordingly, one object of this invention is to provide novel means for causing an automatic reclosing circuit breaker to open the circuit with time delay on a selected one or ones of a plurality of closely successive circuit interrupting operations.

Another object of this invention is to provide novel means for causing ,an automatic reclosing circuit breaker to delay opening the circuit with thermal characteristics on at least one selected circuit opening operation in a series of closely successive circuit interrupting operations, with at least one other circuit opening operation of said series being substantially instantaneous.

A more specific object of this invention is to provide in an automatic reclosing circuit breaker having integrating means to lock the breaker contacts open in response to a predetermined number of closely successive circuit interrupting operations, novel means controlled by said in tegrating means for determining the time characteristics of such closely successive circuit interrupting operations.

Another object of this invention is to provide an automatic reclosing circuit breaker which is adapted to lock at open circuit position in response to a predetermined number of closely successive circuit interrupting operations, with means for causing a selected one of such predetermined number of operations to always occur with a relatively large time delay, irrespective of whether or not said breaker completes said predetermined number of closely successive circuit interrupting operations.

These and other objects of this invention will become more apparent upon consideration of the following detailed description of preferred em bodiments thereof, when taken in connection with the attached drawings, in which:

Figure l is an elevation of a reclosing interrupter embodying this invention, illustrated partially in section;

Fig. 2 is a cross-section of the interrupter shown in Fig. 1, taken substantially on the line 11-11 thereof;

Fig. 3 is an enlarged elevation view of a portion of the control mechanism with certain of the parts shown in section, and with the view taken substantially on the line III--III of Fig. 2;

Fig. 4 is a line diagram illustrating the method of connection of applicants novel circuit interrupter and its control means in a circuit;

Fig. 5 is an elevation view of a modified form of control means, with certain of the parts shown in section; and

Fig. 6 is a line diagram illustrating the circuit connections for the control means shown in Fig. 5.

This invention is illustrated as embodied in a reclosing circuit breaker which is similar to that disclosed in 'applicants copending application Serial No. 399,453, filed June 24, 1941, now Patent No. 2,333,604, and assigned to the same assignee of this invention. Such a breaker is provided in a tubular casing 2 of insulating material such, for example, as porcelain or the like. Casing 2 preferably has an open top and a closed lower end, as illustrated, and may be supported from an intermediate portion thereof, for example, as by a supporting bracket 3, or the like. A terminal bolt 4 is provided through an aperture in the closed lower end of casing 3, and the bolt is provided with an enlarged head 6 within the casing, and is held in position by a nut 8 which also secures a line terminal ID in conducting relation to the bolt. Packing material 1 is preferablyprovided beneath the head 6 of terminal bolt 4 to seal the opening in the lower end of casing 2. A hollow terminal cover assembly I! is adapted to be seated on the open upper end of casing! and be secured thereto in any desired manner such, for example, as by bolts (not shown) joining the cover assembly and an anchoring ring l8 suitably secured to the upper end of casing 2. Cover assembly i2 is provided with a terminal strap |4 suitably secured to the cover as by a bolt I8, and the terminal strap i4 carries a line terminal clamp I8. A filler plug 20 may be provided for the cover assembly, to permit filling container 2 with liquid when required.

Within casing 2 at the lower end thereof there is provided an arc chamber 22 comprising a tube 24 of insulating material such, for example, as fiber or the like, having end caps 26 and 28 threadedly engaged with the respective ends of tube 24. The lower end cap 28 is provided with a central threaded aperture for receiving a fixed contact 30 which is threaded into the opening, and secured in adjusted position by a lock nut 8|. A movable contact 32 is also provided within the arc chamber for cooperation with fixed contact 30, with contact 32 being provided on the lower end of a contact rod 33 which extends through a central opening in the upper cap 28. Movable contact rod 33 is provided with a sleeve 34 of insulating material such, for example, as fiber or the like; and this sleeve closely fits the opening in cap 26 and is secured on contact rod 33 in any desired manner such, for example, as by a tight friction fit. Interrupter chamber end caps 26 and 28 are each provided with apertures 36 and 38, respectively, to permit the flow of fluid into and out of the chamber, with openings 38 being controlled by valve plate 48 movable between the upper end of tube 24 and cap 28. Openings 38 in cap 28 are controlled by a valve plate 42 freely movable between end cap 28 and a stop ring 29 secured in position by the end cap. A liquid directing piston 4| is slidably mounted on the outer reduced end of contact rod 33 for limited movement between sleeve 34 and contact 32.

Piston 4| is biased toward contact 32 by a spring 43 and in the closed circuit position, the piston normally engages stop ring 28.

When contact 32 is moved away from fixed contact 30, an arc will be struck, and since the arc chamber is filled with an arc-extinguishing liquid such as oil, the arc will decompose some of the oil and create a pressure within the arc chamber. The rise in pressure within arc chamber 22 will cause both valve plate 48 and valve plate 42 to seat against openings 38 and 38 to effectively close the arc chamber. The pressure generated within arc chamber 22 is thus confined to the chamber and is available to act on the moving contact assembly, comprising rod 33 and sleeve 34, to move it outwardly relative to the chamber and away from fixed contact 38 in a piston-like manner, to draw out the arc and thus aid in extinguishing it. As soon as the arc is extinguished, the pressure in chamber 22 will decrease and this will allow valve plates 48 and 42 to uncover openings 38 and 38. By uncovering openings 36, gases generated by decomposition of the arc-extinguishing fluid will be permitted to escape from chamber 22, and fresh fluid from casing 2 will flow in through openings 38 to replace the used liquid and gases, due to the head of liquid above openings 38. A flushing of the arc chamber 22 will thus occur after each circuit interrupting operation, prior to or during the reclosing operation of the breaker contacts. In a circuit opening operation, piston 4| is not moved until engaged by contact 32, thereafter continued movement causes piston 4| to move into the contact to cause a stream of arc extinguishing liquid to flow through the arc.

Movable contact 82 of the breaker may be separated from fixed contact 88 by a solenoid coil 44 connected in series in the circuit. The solenoid coil is preferably formed on an insulating supporting collar 48, and is supported in a hollow supporting frame 48 of a magnetic material, such as soft iron or the like. Hollow supporting frame 48 is secured to the top cover structure by bolts l8 and has at least one open side to permit insertion and removal of the solenoid coil, and removal of the solenoid coil from the hollow supporting frame is normally prevented by a cylindrical sleeve 58 of insulating material, such as fiber or the like, which maintains a flanged collar 52 into engagement with a flange about a central opening in the upper side of frame 48. Sleeve 58 may be inserted in frame 48 through an opening in the lower side oi the frame, and is maintained in this position by a. substantially rectangular supporting frame 54 which is bolted to solenoid frame 48 by bolts 56. Supporting frame 54 may be integral with top cap 28 of the arc chamber, so as to support the arc chamber from the solenoid frame, and the latter is secured to cap assembly |2 as by bolts 56. A cylindrical dashpot piston 58 is slidably mounted within sleeve 58, and this piston is of magnetic material to form a core for solenoid 44 which will be attracted upwardly into the coil upon energization thereof. Piston 58 may be provided with a non-magnetic spacer ring 88, of brass or the like, to prevent residual magnetism from impeding downward movement of piston 58. Piston 58 is provided with a flange 82 defining an opening at the lower end thereof which closely fits an actuating rod 64 extending centrally upwardly through the solenoid and dashpot cylinder and piston structure. Actuating rod 64 is secured to movable contact rod 33 as at 66, so as to actuate contact 22 by movement thereof. The upper end of actuating rod 84 above solenoid supporting frame 48 has a sleeve 68 secured thereto which is adapted to be engaged by a collar I8 slidably mounted on the actuating rod. Collar 18 is threadedly engaged in the upper end of cylindrical tube I2, and a light coil compression spring 14 is positioned within tube 12 and reacts between collar 18 and piston 58, to bias the piston to its lower limit of movement.

Actuating rod 84 is connected by a pair of links 16 of insulating material such, for example. as fiber or the like, to a reclosing crank 18 rotatably mounted on a shaft 88 extending across the hollow space within cover assembly I 2. A generally U-shaped spring control member 82 has the leg portions thereof rotatably mounted on shaft 88, and a coil spring 84 has one end 88 thereof engaging crank 18, and the other end 88 engages spring control member 82 so as to bias crank 18 in a clockwise direction such that movable contact 32 is biased into engagement with fixed contact 38. The contacts are biased into engagement by coil spring 84 only provided that spring control member 82 is maintained against movement. The spring control member 82 is normally held against movement about shaft 88 by an over-center toggle comprising toggle levers 89 and 90 secured to control member 82 and a fixed pivot 9| in the cover, respectively. Toggle levers 89 and 98 are pivoted together and normally maintained, as shown in Fig. 1, below center by the fact that toggle lever 98 has an operating handle 82 which engages an adjustable stop screw 84 mounted in a hood structure 288 integral with cover structure l2.

asoaou It will now be apparent that upon energization liquid level in container 2, and is more particuof solenoid 44, dashpot piston 50 will be attracted larly shown in Fig. 3. As shown in this figure, a upwardly into the coil while compressing spring cylindrical dashpot sleeve I08 is threadedly 14. This movement of piston 58 upwardly will mounted in an aperture provided in the top of be delayed by the necessity of displacing liquid 5 solenoid supporting frame 08, with an apertured entrapped between the piston and collar 52 collar IIO threaded into the lower end of this through the relatively small clearance with aperture to secure a stop washer '3 between the sleeves 00 and 12. Moreover, since Spring 14 is collar and dashpot cylinder I08. A ball check relatively weak, this initial movement of piston valve H2 is adapted to close the opening in col 88 will not actuate movable contact 32 because 10 lar H0, but the ball is freely movable between it is held in closed circuit position by the relathe collar H0 and stop washer H8, all for a purtively strong closing spring 84. Since flange 62 pose to be described. An integrator piston Ill on pis on 58 engages the lower end of sleeve 12 is slldably mounted within dashpot cylinder I08 d fi its upward movement and moves the and is provided above the lower end thereof with sleeve upwardly until collar 10 engages sleeve 88 is a plurality of reduced areas II6 forming in effect on actuating rod 84, a positive drive connection a ratchet formation, which is accessible through with actuating rod 84 is effected to thereby posiopening I25 in cylinder I08. The upper end of tively separate movable contact 32 from fixed ratchet piston II! is threaded for threadedly recontact 30. Separation of the contacts produces ceiving a control section IIO. As shown in Fig. 3, p re within ar chamber 2 a p v usly d the section H8 is of an insulating material, hayscribed, and this pressure acting on the movable ing a reduced threaded extension for receiving contact assembly in a piston-like manner may a control section I20 of conducting material, and

f r r separate h c n a r r d nc the latter in turn has a reduced threaded extenthan t at due to 0l 0 4, be a e the mo e-- sion for receiving an outer section I22 of insuble contact assembly has lost motion relative to 25 lating material. Piston II4 is provided at its piston member 58. After the movable contact upper end with a lock nut I24 for securing sec- 82 has separated from contact a distance suftion H8 at the proper position on the piston. A flciehli to extinguish e Sp g 84 y then generally U-shaped pawl I26 is provided at one e Contact 32 n a reverse direction back t side of dashpot cylinder I08 for cooperation with ward fixed contact 30, because of the reduction 30 the ratchet portion of piston IN. Pawl I26 has in Pressure i t e Chamber, and because 0 the lower leg thereof apertured so as to be slidanO d being in er es in the circuit, will deenble on a fixed guide rod I28 also mounted in the ergize- However, clesing mo t of CO a top of solenoid supporting frame 48. A coil comwill be impeded y the dashpot action f 9 pression spring I30 reacts between a collar fixed ton 8. f d a latch y e provided for on guide rod I20 and the lower leg of pawl i28, to ma a o ac 32 at an open circuit posinormally maintain the pawl seated on solenoid t O W t t latch arranged t0 be pp y supporting frame 48. The upper leg. of pawl I26 piston 58 after predetermined downward moveis slotted as at I32 for receiving the guide rod. ment thereof. Such a latch is fully disclosed in d the big; portion of pawl I28 is also slotted' the abov -m nti n d p n in ap as at m for receiving sleeve to mounted on th In order to maintain the breaker contacts upper d f ctuating rod 64. parated when toggle 89. 9 is moved upwardly The integrator structure thus far described is er n a r d 98 s pivoted to spring control actuated upon each circuit interrupting o eram r 8 d is dfl y received in an p tion of the breaker by upward movement of collar tured ear I00 integral with cover structure i2. 10, whe moved upwardly, collar 10 engages Coil compr ssi n spri 0 surr u s r d 8. the bight portion of awl I26 to pivotally move and reacts between ear I00 and a collar I04 fixed the pawl so that end I29 thereof moves into en. to the rod to bias the rod long tud y t the gagement with a reduced section IIS of piston left, as viewed in Fig. 1 and consequently bias H4. Further upward movement of collar 10 spring control member 82 for rotation in councauses upward movement of the pawl and piston terclockwise direction about its supporting shaft II4 a predetermined amount. Upward move- 80. Toggle levers 89 and 90,- when below center ment of piston Ill causes ball valve M2 to be in the position shown in Fig. l, normally prevent unseated so that liquid is drawn into the lower movement of spring control member 82 by spring H end of dashpot cylinder I08. Upon reclosure of I02,but when the toggle is moved upwardly overthe circuit breaker, pawl I26 is moved downcenter, for example as by manually pulling downwardly and withdrawn from engagement with wardly on operating handle 92, spring I02 will a reduced section of piston II4 by compression then be free to expand and to maintain the spring I30. If the condition causing opening of breaker contacts in open circuit position. Operthe breaker has disappeared upon reclosure ating handle 92 may be provided with an enthereof, piston II4 will slowly return to the posilarged hook-eye aperture I06 for the reception tion shown in Fig. 3 under the influence of gravof a hookstick operating member or the like. ity. This return movement is very slow because Integrating means is provided for counting the of the dashpot action requiring liquid drawn into number of closely successive circuit interrupting cylinder I08 beneath piston H4 to be displaced operations of the breaker to automatically move through the relatively sma l Clearance w en toggle levers 89 and 90 upwardly ovcrcenter in rethe piston and cylinder. If the overload which sponse to a predetermined number of closely succaused the first circuit interrupting operation has cessive circuit interrupting operations to autonot cleared upon the first reclosuie of the matically move the breaker contacts to open cirbreaker, the breaker will immediately reopen, cult condition, and to maintain them in such con- 79 and this time pawl end I29 will engage the next dition until manually reset. The integrating lower reduced section II6 of piston II4, because means as well as the novel control for determinthe piston will not as yet have had time to reing the time characteristic of successive circuit turn to its original position. Accordingly, a second closely successive circuit interrupting opinterrupting operations is mounted on top of Y m eratlon will cause piston I It to be advanced up:

solenoid supporting frame 48 below the normal wardly beyond the position to which it is moved on the first circuit interrupting operation. Now upon the second reclosure of the breaker, dashpot piston I I4 will reset to its original position if the contacts do not immediately open. However, if the fault is still present on the circuit, the breaker will again immediately reopen, and this time pawl end I29 will engage the next lower reduced section I I6 of piston H4, and this time the piston will be raised far enough so that end section I22 will engage the knee of toggle levers l and 90 to move them overcenter and release spring I02, and permit it to maintain the breaker contacts at open circuit position. With the integrator structure described above, it will be apparent that the breaker contacts will be locked or maintained in open circuit position by spring I02 only in response to a predetermined number (three or four in the embodiment illustrated) of closely successive circuit interrupting operations. If the overload or fault clears before the breaker has time to complete this predetermined number of closely successive circuit interruptin operations, then the integrator structure will reset so that the next time a fault appears upon the circuit the breaker will go through the same predetermined number of closely successive circuit interrupting operations before the contacts are maintained open by spring I02.

Solenoid 44 being connected in series in the circuit acts substantially instantaneously in response to an overload or a short circuit to separate the circuit breaker contacts. Since a high percentage of faults are of the self-clearing type, it is desirable that upon the occurrence of a fault at least one of the circuit interrupting op rations of the breaker before lockout of the breaker be delayed for a predetermined time to permit the fault to clear itself, if it is of that type. It is generally desirable that this time delay be introduced upon the second successive circuit interrupting operation of the breaker. This will give a first instantaneous circuit opening operation which is fast enough to open the circuit before any branch circuit fuses blow, so that if the fault is merely transient in nature, it will have cleared upon reclosure and service will be fully restored on all circuits. However, if the fault is still on the circuit upon the first reclosure, a time delay introduced at this time permits the fuse protecting the faulted branch circuit to blow before the second opening and subsequent reclosure so that upon the second reclosure the faulted branch will have been isolated and service will be restored to all other branch circuits. If the fault has not then cleared, it may be desirable to make the third successive circuit opening instantaneous, so that lockout will immediately take place. It is also desirable that the time delay interrupting operation of breaker have thermal characteristics to permit better coordination with fuses and with other breakers. One manner of accomplishing the foregoing desirable results is by using the integrator structure described above to control operation of solenoid 44.

As shown in Figs. 3 and 4, a contact finger I36 is supported on the upper end of guide rod I28, and this contact finger is adapted to bear on one side of the upper end of piston II 4 made up of control sections l I8, I and I22. A contact finger I38 is supported in a position to engage the opposite side of the upper section of piston H4, by an angular supportin bracket I40 of insulating material also mounted on solenoid supporting frame 48. Bracket I40 also supports a bimetal element which is preferably of the snapacting type. The bimetal element illustrated may be of the circular disc type comprising a pair of metallic laminations intimately secured together in a manner well known in the art, with lamination I42 being of a material which has a relatively low coefficient of thermal expansion such as steel, and the lamination I44 being of a material having a relatively high coefficient of thermal expansion such as brass or the like. This composite disc MI is preferably concave-convex in section, so that upon reversal of curvature thereof, the disc will change its convexity with a snap action. To take advantage of this action of the disc. it is preferably supported at opposed points adjacent the periphery thereof, and the central part of the disc is provided with a contact I46 normally engageabl with a contact I40 mounted on a bracket I41, of insulating material.

Referring to Fig. 4, it will be observed that solenoid 44 is connected in series in the circuit, by a conductor I50 with contacts 30 and 32 of the breaker. Conductor I50 is also connected with contact I48 and bimetal element I4I. Conductor I52 associated with contact finger I30 connects this contact finger to the other side of solenoid coil 44, so that the bimetal element HI and the switching means, comprising contact fingers I30, I 38 and the integrator piston, are connected in series in a shunt circuit about solenoid coil 44.

At the position of the parts shown in Figs. 3 and 4, the shunt circuit including bimetal element MI is open, so that all of the current must pass through solenoid 44. This means that, when a fault appears upon the circuit, the breaker will be relatively instantaneously opened by the solenoid coil 44. This opening operation of the breaker advances integrator piston H4 in the manner described above, so as to bring conducting control section I20 thereof into a position where it bn'dges contact fingers I36 and I38. Now upon reclosure of the breaker, it will be observed that the shunt circuit about solenoid coil 44 including bimetal element I4I will be closed. Since this shunt circuit has less impedance than the solenoid coil, it will carry substantially all of the current, so that if the fault is still on the circuit upon the first reclosure, solenoid 44 is ineffective to cause a second opening of the breaker because it is bypassed by the shunt circuit including blmetal element MI. The overload current will cause heating of bimetal disc I4I up to the point where it reverses its curvature with a snap action to separate its contact I46 from fixed contact I48, thus opening the shunt circuit for the solenoid coil, whereupon the solenoid coil 44 again carries the overload current and effects an opening of the breaker contacts. Upon this second closely successive circuit opening operation of the breaker, piston control section I I8 is elevated to a position between contact fingers I36 and I30 to thereby open the shunt circuit about solenoid coil 44, so that upon the second reclosure the third opening operation will be relatively instantaneously effected by solenoid coil 44, if the fault still remains on the circuit. It will be noted that the provision of switching means for the shunt circuit includes a bimetal element I4I the energization of which is controlled by the position of integrator piston II4, so that a predetermined sequence of instantaneous and time delay circuit interrupting operations is insured, whenever the breaker goes through its predetermined number. of circuit interrupting operations and finally locks the circuit open. Moreover, if the fault clears before lockout of the breaker, the inte- 10 grater resets, as previously described, so that if pin I80 on a supporting bracket I82 which may a fault again comes on the circuit at a later time, be welded or otherwise secured on dashpot cylinthe means controlling the time characteristic of der I08. A spring I84 is coiled about pivot I80 the circuit interrupting operations is also reset, and reacts between insulating button I8I on and the same sequence of instantaneous and time bracket I82 and the bimetal element to bias the delay circuit interrupting operations will occur. bimetal element for pivotal movement in a clock- The integrator structure disclosed, thus not only wise direction. Dashpot piston H4 in this emdetermlnes the number of closely successive cirbodiment of the invention is provided with a solid cult interrupting operations which occur prior to extension I88 secured to the upper end thereof, lockout of the breaker and resets so that the 10 and has aresetting lug I90 of insulating material, breaker looks out only in response to that numwhich normally engages the inner end of bimetal .ber of closely successive circuit interrupting opelement I14 to maintain the bimetal element at erations, but this integrator also determines the a position wherein catch I12 is out of the path time characteristic of closely successive circuit of movement of the latching tip of bell crank I62. interrupting operations, and is arranged so that 15 Fig. 6 illustrates how this control assembly is conthe resetting of the integrator also resets the nected in the circuit with conductor I82 secured time characteristic control so that the same seto the inner end of bimetal element I14 being conquence of instantaneous and time delay circuit nected to one side of solenoid coil 44. The outer interrupting operations always occurs on closely end of bimetal element I14 is connected by flexisuccessive circuit interrupting operations. go ble conductor I08 to the bell crank lever and its In Figs. 5 and 6 of the drawings, there is illuscontact I80, and the other contact I54 is contrated a modified form of control means for denected by a conductor I94 with the other side of termining the time characteristic of closely sucsolenoid coil 44.

cessive circuit interrupting operations. This con- In the normal closed circuit position of the trol means also may be associated with the integ5 breaker shown in Figs. 5 and 6, the contacts I54 grator structure shown in Figs. 1 to 4, and since and I80 of the shunt circuit for solenoid coil 44 most of this structure is identical with that preare at their open circuit position, so that when a viously described, like reference numerals are fault occurs on the circuit, solenoid 44 is able to used to designate such identical parts. In this effect a first circuit interrupting operation at embodiment of the invention, but a single set of substantially the same instant the fault occurs. contacts is provided for control of a shunt circuit This circuit interrupting operation results in upabout solenoid coil 44, and these comprise a fixed ward movement of collar 10 and consequent contact I54 mounted on a supporting bracket movement of contact I60 into engagement with I58 suitably secured to the frame 48 for solenoid fixed contact I54. Upward movement of collar 44, for example, as by a screw I58 with washers 10 also actuates pawl I26 to move dashpot piston I80 of insulating material interposed between the H4 upwardly, thereby moving resetting lug I90 bracket, frame and screw to electrically isolate out of engagement with bimetal element I14, and these parts. A contact I80 is provided on a bell permitting spring I84 to move bimetal element crank I82 pivotally mounted on the solenoid sup- I14 in a clockwise direction about its pivot I80 porting frame by an insulating pivot pin I84, and until the inner end thereof engages insulating is normally biased inacounterclockwise direction stop collar I88 provided at the upper end of to maintain the contacts separated, by a coil dashpot cylinder I08. At this position of the bispring I88 wound about pivot axis I84 and reactmetal element, catch I12 will be positioned being between the bell crank lever and solenoid suphind latching tip I10 of bell crank I82, so that porting frame 48. An adjustable stop screw I88 4, the bimetal element will be eilective to mainis threadedly engaged through the leg of bell tain contacts I54 and I80 in engagement. Accrank lever I82 adjacent the supporting frame, so cordingly, when the circuit breaker is reclosed, as to be engageable with the frame and limit the shunt circuit including bimetal element I14 movement of the bell crank in a direction to sepabout solenoid coil 44 will be closed, and since this arate contact I80 from contact I54. It will be circuit has less resistance or impedance than solenoted that the end "I of the bell crank lever noid coil 44, substantially all of the current will overlies collar 10 so that upon a circuit interpass through the bimetal element when the rupting operation of the breaker bell crank I82 breaker is reclosed. If the fault clears upon this will be rotated in a clockwise direction by upward first reclosure of the breaker, dashpot piston lI4 movement of collar 10 to cause contact 80 to enwill'slowly sink to its original position, as previgage contact I54, and thus close the shunt circuit ously explained, until resetting lug I90 engages about solenoid coil I44. Contact I80 is adapted the bimetal element and rotates it in a counterto be latched in engagement with contact I54 by clockwise direction to remove catch I12 from a catch I12 which is engageable with the curved latching tip I10 of bell crank lever I62, to thereby latching tip I10 of the bell crank under certain permit spring I88 to separate the contacts and conditions which will hereinafter be pointed out. reset them in open circuit position, as shown in Catch I12 is provided on the outer end of an ordi- Fig. 5. However, if the fault has not cleared upon nary strip bimetal element I14. This type of bithe first reclosing operation ,of the breaker, the

metal element is well known in the art, and combreaker will not immediately reopen because it prises a pair of laminations I18 and I18 of difIerwill be necessary to wait until bimetal element I14 ent materials having relatively low and high cohas heated suiliciently to deflect enough to remove eilicients of thermal expansion, respectively. In catch I12 from behind latching tip I10 and perthis instance, the bimetal element I14 is posimit spring I88 to open contacts I54 and I60. tioned with the low coeflicient of expansion lami- Only after this has occurred will solenoid coil 44 nation I18 at the upper side, and with the high be energized sufficiently to open the circuit breakcoeiiicient of expansion lamination I18 at the er contacts. Upon the second reclosure of the lower side, so that upon heating, the bimetalelecircuit breaker, bimetal. I14 will not have had time ment will bend so as to be concave upwardly, from to cool down sufdciently to resume its normal the position shown in Fig. 5. Bimetal element straight condition, so that if the fault remains I14 is pivotally mounted on an insulating pivot on the circuit the third and flnal circuit interrupting operation will occur substantially instantaneously, because the solenoid coil 44 is not shunted by the bimetal element. Accordingly, upon the occurrence of continuing overloads or faults, the control means illustrated in Figs. and 6 provide a first substantially instantaneous circuit interrupting operation, followed by a second time delayed circuit interrupting operation and finally a third substantially instantaneous interrupting operation, prior to lockout of the breaker. Furthermore, if at any time the overload or fault be cleared, the control means for determining the time characteristic of closely successive circuit interrupting operations will be reset to provide the same sequence of instantaneous and time delayed circuit interrupting operations in the event of a plurality of closely successive operations of the breaker occurring in response to a fault which comes on the circuit at a later time.

With the exception of the particular means controlling the time characteristic of closely successive circuit interrupting operations disclosed herein, the remaining features and structures of the breaker are substantially the same as the corresponding features and structures of the breaker disclosed in the above-mentioned copending application; such features including in addition to those already mentioned, the provision of a lightning arrester assembly I98 mounted'within the hollow cover structure I! and adapted to be connected in shunt with solenoid coil 44 as by conductor 230, a counting device 202 may also be provided beneath hood structure 208 integral with the cover structure l2, with the counting device actuated by a link 204 connected to an actuated crank 206 movable with crank 18 so that each interrupting operation will be recorded. Accordingly, for a more detailed description and better understanding of these and other features previously described, reference is hereby made to the aboveidentified copending application.

From the foregoing, it is apparent that this invention provides a novel electrical control for determining the time characteristics of closely successive circuit interrupting operations of an automatic reclosing circuit breaker, to provide at least a first substantially instantaneous circuit interrupting operation, a second time delayed opening operation, and a third instantaneous opening of the breaker, in any series of closely successive interrupting operations prior to lockout of the circuit breaker. Furthermore, by the association of the control means with integrator structure for causing the lookout operation, the

control means is reset if the fault clears prior to lockout, so that when a fault appears upon the circuit at a later time the same-sequence of instantaneous and time delayed circuit interrupting operations will occur. Thus, an automatically reclosing circuit breaker is provided which is not only responsive solely to a predetermined number of closely successive circuit interrupting operations to lock the breaker contacts open, and in the event of the occurrence of less than this predetermined number of closely successive interrupting operations the breaker will reset so as to require the same predetermined number of closely successive interrupting operations when a fault appears on a circuit at a later time, but there is also provided means for obtaining diil'erent time characteristics of this same predetermined number of closely successive circuit interrupting operations, which means also resets in the event a smaller number of closely successive circuit in- 12 terrupting operations occurs so that the same sequence of instantaneous and time delayed circuit interrupting operations will occur when a fault appears upon the circuit at a later time.

Having described preferred embodiments of the invention in accordance with the patent statutes, it is desired that the invention be not limited to the particular embodiments illustrated, inasmuch as it will be obvious to persons skilled in the art that many changes and modifications may be made in these particular embodiments without departing from the broad spirit and scope of this invention. Thus, for example, it is apparent that in the modification illustrated in Fig. 3 that instead of providing the nrst interrupting operation be instantaneous, the second time delayed, and the third instantaneous, any desired sequence of instantaneous and time delayed circuit interrupting operations may be obtained, by merely changing the order in which control sections H8, and I22 are mounted on the outer end of integrator piston ill. Thus, by mounting conductor section I20 above sections I I8 and III, a first time delayed interruption, and second and third instantaneous interruptions will be obtained. Accordingly, it is desired that the invention be interpreted as broadly as possible, and be limited only as required by the prior art.

I claim as my invention:

1. In an automatic reclosing circuit interrupter, separable contacts adapted to separate to open the circuit, means for automatically reclosing said contacts in response to a circuit interrupting operation thereof, electro-responsive means substantially instantaneously responsive to predetermined electrical conditions in the circuit for causing separation of said contacts, second electro-responsive means responsive to said predetermined conditions for causing separation of said contacts a predetermined time after the occurrence of said conditions, a single electrical control means connected in a circuit with both of said electro-responsive means for determining which one of said condition responsive means will be effective to cause separation of said contacts, and means actuated by said interrupter on each circuit opening operation of said contacts, for actuating said control means, whereby successive circuit interrupting operations may have successively different time characteristics.

2. In an automatic reclosing circuit interrupter, separable contacts adapted to separate to open the circuit, means for automatically reclosing said contacts in response to a circuit interrupting operation thereof, electro-responsive means substantially instantaneously responsive to predetermined electrical conditions in the circuit for causing separation of said contacts, second electro-responsive means responsive to said predetermined conditions for causing separation of said contacts a predetermined time after the occurrence of said conditions, electrical control means having a normal position, said control means connected in a circuit with both of said electro-responsive means determining which one of said condition responsive means will be efl'ective to cause separation of said contacts in accordance with the amount said control means is advanced from its normal position, and means actuated by said interrupter on each circuit opening operation thereof for advancing said control means a predetermined amount in response to each circuit opening operation of said interrupter, whereby successive circuit interrupting operations may have successively difl'erent time charsaid instantaneous means, and means actuated acteristics. by said interrupter for actuating said control 8. In an automatic reclosing circuit interrupter, switch means in response to a circuit opening opaeparable contacts. adapted to separate to open eration of said interrupter, whereby the next suethe circuit, means for automatically reclosing said ceeding circuit interrupting operation will have contacts in response to a circuit interrupting opa different time characteristic than the preceding eration thereof, means substantially instantaneinterrupting operation. ously responsive to predetermined electrical con- 6. In an automatic reclosing circuit interrupter.

ditions in the circuit for causing separation of said separable contacts adapted to separate to open ive to said predetermined the circuit, means for automatically reclosing said contacts, means respons conditions for causing separation of said contacts contacts in response to a circuit interrupting opa predetermined time after the occurrence of said oration thereof, means substantially instantaneconditions, electrical control means having a norously responsive to predetermined electrical conmal position, said control means determining ditions in the circuit for causing separation of which one of said condition responsive means will 1 said contacts, normally closed time delay switch be efiective to cause separation of said contacts means responsive to said predetermined condiinaccordance with the amount said control means tions for opening its contacts a predetermined is advanced from its normal position, means for time after the occurrence of said conditions, conslowly moving said control means back to its nortrol switch means for connecting said time delay mal position when it has been advanced thereswitch means in shunt circuit with said instantafrom, and means actuated by said interrupter for w eans, mea s act ated by sa d nt p advancing said control means a predeter ined for actuating said control switch means comprisamount in response to each circuit opening Qping an integrating member which is advanced a eration of said interrupter, whereby closely sucpredetermined amount from 8 normal position cessive circuit interrupting operations of said in response to each circuit op in Op ion of e successively diflerent time said interrupter, and means for slowly moving interrupter may ha characteristics, and each series of closely success d in e rating member back toward its normal position, whereby closely successive circuit intersive circuit interrupting operations will have the same time pattern of circuit interrupting operarup ns p rati ns f said interrup r may hav {210115, successively different time characteristics, and 4. Inan automatic reclosing circuit interrupter, each series of closely successive circuit interruptseparable contacts adapted to separate to ope ing operations will have the same time pattern of the circuit, means for automatically reclosing said l r p n p io contacts in response to a circuit interrupting 7- In n automatic reclosing circuit interoperation thereof, means substantially instantarupter, separable eentaets adopted 1 p ra e neously responsive to predetermined electrical 150 p n the i means f m i lly reconditions in the circuit for causing separation of losing said contacts in response to a circuit in said contacts, means responsive to said predeter" l g operation thereof, me n Substantially mined conditions for causing separation 01 said instantaneously responsive to predetermined e e contacts 9, predetermined time after the occur- 40 trical conditions in the circuit for causing separarence of said conditions, electrical control means tion or said contacts, normally closed time delay having anormal position, said control e n d switch means responsive to said predetermined termining which one of said condition responsive conditions for opening its contacts a predetermeans will be efiective to cause separation of said mined time after the occurrence of said condi contacts in accordance with the amount said tions, control switch means for connectin d control means is advanced from its normal positime delay switch means in shunt circuit with tion, means for slowly moving said control means said instantaneous means, means for actuating back to its normal position when it has been adsaid control switch means comprising an invanced therefrom, means actuated by said intertegrating member which is actuated b said inrupter for advancing said control means a preterrupter to be advanced a predetermined amount determined amount in response to each circuit from a normal position in response to each ciropening operation of said interrupter, whereby cult opening operation of said interrupter, means closely successive circuit interrupting operations for slowly moving said integrating member back of said interrupter may have successively diflertoward its normal position, whereby closely sucent time characteristics, and each series of closely 5 cessivecircuit interrupting operations of said insuccessive circuit interrupting operations will terrupter may have successively different time have the same time pattern of circuit interrupting characteristics, and each series of closely succesoperations, and means responsive to advancement sive circuit interrupting operations will have the of said control means an amount greater than a same time pattern of circuit interrupting operapredetermined multiple of said predetermined 50 tions, and means responsive to advancement of amount for maintaining said separable contacts said control means an amount greater than a in open circuit position, predetermined multiple of said predetermined 5. In an automatic reclosing circuit interamount for maintaining said separable contacts rupter, separable contacts adapted to separate inopen circuit position. to open the circuit, means for automatically re- 8. In an automatic reclosing circuit interclosing said contacts in response to a circuit interrupter, separable contacts adapted to separate rupting operation thereof, means substantially to open the circuit, means for automatically reinstantaneously responsive to predetermined elecclosing said contacts in response to a circuit intrical conditions in the circuit for causing separaterrupting operation thereof, means substantially tion o Sa d contacts, normally Cl time delay instantaneously responsive to predetermined elec- -switch means responsive to said predetermined trical conditions in the circuit for separating conditions for opening its contacts a predetersaid contacts, electroresponsive means for premined time after the occurrence of said condiventing said contact separating means from eftions, control switch means for connecting said fecting a circuit interrupting operation, switching time delay switch means in shunt circuit with means actuated by said interrupter in response to each of a plurality of circuit opening operations of said contacts in any series of closely successive circuit interrupting operations for opening and closing the circuit of said electroresponsive means to render said electroresponsive means ineffective and effective, respectively, to prevent operation of said-condition responsive means, i said electroresponsive means when rendered *ective being responsive to said predetermined conditions only a predetermined time after the occurrence thereof to render said contact separatmeans effective to separate said contacts, i iere'cy said contacts are separated substan- "v instantaneously in at least one operation d series, and with a time delay in at least operation or" said series. automatic reclosing circuit interseparable contacts adapted to separate can the circuit, means for automatically rcg said contacts in response to a circuit ining operation thereof, means substantially -taneously responsive to predetermined elec- 1 conditions the circuit for separating said cts, electroi sponsive means for preventing contact .ating means from effecting a cult interrupting operation, integratin means ich is advanced said. interrupter a preerlnined amount from a normal position in use -to eats cuit opening operation of contacts, w- "i for slowly returning said. to its normai position after "ancernent, whereby said integrating member will "be advanced an amount greater than said predetermin d amount in response to a plurality clmely successive circuit interrupting operaor will reset its normal position in the event successive circuit interrupting operations :29 not closely succeed each other, switching means controlled by the position occupied by said grating member for opening and closing the rcuit of said electroresponsive means to render electrorespcnsive means effective or ineffective to prevent separation of said contacts,

electroresponsive means when rendered effective responding to said predetermined conditions a predetermined time after the occurrence thereof to render said contact separating means effective to separate said contacts, and means actuated by said integrating means when advanced said greater amount to maintain said contacts separated.

ii). In an automatic reclosing circuit interrupter, separable contacts adapted to separate to open the circuit, means for automatically reciosing said contacts in response to a circuit interrupting operation thereof, means substantially instantaneously responsive to predetermined elec trical conditions in the circuit for causing separation of said contacts, means responsive to said predetermined conditions for causing separation of said contacts a predetermined time after the occurrence of said conditions, said time delay means being adapted to control separation of said contacts when both of said means are operatively connected to the circuit, switching means for controlling the connection of said time delay means to the circuit, and means actuated by said interrupter for actuating said switching means in response to each circuit opening operation of said interrupter, whereby successive circuit interrupting operations may have successively difierent time characteristics.

11. In an automatic reclosing circuit interrupter, separable contacts adapted to separate to open the circuit, means for automatically reclosing said contacts in response to a circuit interrupting operation thereof, means substantially instantaneously responsive to predetermined electrlcal conditions in the circuit for causing separation of said contacts, means responsive to said predetermined conditions for causing separation of said contacts a predetermined time after the occurrence of said conditions, said time delay means adapted to control separation of said contacts when both of said means are operatlvely connected to the circuit, switching means for controlling the connection of said time delay means to the circuit, means actuated by said interrupter for actuating said switching means in response to each circuit opening operation of said interrupter, whereby successive circuit interrupting operations may have successively different time characteristics, said switch actuating means having a normal position at which said switching means disconnects said time delay means from the circuit, and means biasing said switch actuating means for slow movement back to its normal position in response to an actuation thereof, whereby the first operation of any series of closely successive circuit interrupting operations will occur substantially instantaneously, and the second operation will be delayed a predetermined time.

12. In an automatic reclosing circuit interrupter, separable contacts adapted to separate to open the circuit, means for automatically reclosing said contacts in response to a circuit interrupting operation thereof, electromagnetic means connected in series with said contacts to separate said contacts in response to overloads greater than a predetermined value, a low resistance shunt circuit around said electromagnetic means containing current responsive time delay circuit opening means, means actuated by said interrupter in response to a predetermined circuit opening operation for closing said shunt circuit, whereby at least the next closely succeeding circuit interrupting operation is delayed for the period of time required for operation of said time delay means.

13. In an automatic reclosing circuit interrupter, separable contacts adapted to separate to open the circuit, means for automatically reclosing said contacts in response to a circuit interrupting operation thereof, electromagnetic means connected in series with said contacts to quickly separate said contacts in response to overloads greater than a predetermined value, a. low resistance shunt circuit around said electromagnetic means containing current responsive time delay circuit opening means, means actuated by said interrupter in response to a predetermined circuit openin operation for closing said shunt circuit, whereby at least the next closely succeeding circuit interruptin operation is delayed for the period of time required for operation of said time delay means, and means for opening said shunt circuit a greater predetermined time after said predetermined circuit interrupting operation so that a series of circuit interrupting operations occurring at a later time will have the same sequence with respect to time characteristics.

14. In an automatic reclosing circuit interrupter, separable contacts adapted to separate to open the circuit, means for automatically reclosing said contacts in response to a circuit interrupting operation thereof, electromagnetic means connected in series with said contacts to separate said contacts in response to overloads greater than a predetermined value. a low resistance shunt, circuit around said electromagnetic means containing current, responsive circuit opening means for controlling at least a predetermined circuit opening operation of a series of successive circuit opening operations by said electromagnetic means, and means actuated by said interrupter for opening said shunt circuit in response to a predetermined circuit opening operation 01 any such series of operations.

15. In an automatic reclosing circuit interrupter, separable contacts adapted to separate to open the circuit, means for automatically reclosing said contacts in response to a circuit interrupting operation thereof, electromagnetic means connected in series with said contacts to separate said contacts in response to overloads greater than a predetermined value, a low resistance shunt circuit around said electromagnetic means containing current responsive circuit opening means for controlling at least a predetermined circuit opening operation of a series of successive circuit opening operations by said electromagnetic means, means for delaying a circuit opening operation of said current responsive means, and means actuated by said interrupter for opening said shunt circuit in response to a predetermined circuit opening operation of any such series of operations.

16. In an automatic reclosing circuit interrupter, separable contacts adapted to separate to open the circuit, means for automatically reclosing said contacts in response to a circuit interrupting operation thereof, electromagnetic means connected in series with said contacts to separate said contacts in response to overloads greater than a predetermined value, means for delayin a predetermined circuit opening operation of said electromagnetic means including a low resistance circuit connected in shunt relation with said electromagnetic means at least on said predetermined circuit opening, current responsive time delay circuit opening means in said shunt circuit, and means actuated by said interrupter for opening said shunt circuit in response to a predetermined circuit opening operation of any such series of operations.

17. In an automatic reclosing circuit interrupter, separable contacts adapted to separate to open the circuit, means for automatically reclosing said contacts in response to a circuit interrupting operation thereof, means substantially instantaneously responsive to predetermined electrical conditions in the circuit for causing separation of said contacts, means responsive to said predetermined conditions for causing separation oi said contacts a predetermined time after the occurrence of said conditions, electrical control means having a" normal position, said control means determining which one of said condition responsive means will be effective to cause separation of said contacts in accordance with the amount said control means is advanced from its normal position, means for slowly moving said control means back to its normal position when it has been advanced therefrom, means actuated by said interrupter for advancing said control means a predetermined amount in response to 18 each circuit opening operation of said interrupter, whereby closely successive circuit interrupting operations of said interrupter may have successively different time characteristics, and each series of closely successive circuit interrupting operations will have the same time pattern of circuit interrupting operations, means responsive to advancement of said control means an amount greater than a predetermined multiple of said predetermined amount for maintaining said separable contacts in open circuit position.

and means for preventing return 01' said control means when said contacts are maintained separated. 7

18. In an automatic reclosing circuit breaker, separable contacts, electroresponsive means having a single movable portion for always causing separation of said contacts in response to a predetermined electrical condition of the circuit, said contacts automatically reclosing in response to a circuit interrupting operation, means responsive to a sequence of a predetermined number of closely successive circuit interrupting operations to cause said contacts to remain separated, normally ineffective electroresponsive time delay means, means electrically connecting said time delay means and said solenoid coil and being responsive to at least one circuit interrupting operation for delaying a closely succeeding circuit opening operation by said electroresponsive means, the movable portion of said electroresponsive means being at all times free from a mechanical restraining interlocking of said time delay means.

19. An automatic reclosing circuit breaker, comprising, separable contacts, a solenoid coil connected in series circuit relation with said contacts for causing separation of said contacts in response to over-currents in the circuit, means for automatically closing said contacts following a circuit opening operation thereof, normally ineffective electroresponsive time delay means, means electrically connecting said time delay means and solenoid coil and operated by said breaker for rendering said time delay means effective to delay the next closely succeeding circuit opening operation of said breaker, and said solenoid having a movable core for always causing contact separation which is at all times free from a mechanical restraint by said time delay means.

JAMES M. WAILACE.

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

UNITED STATES PATENTS Number Name Date 508,652 Thomson Nov. 14, 1893 1,648,508 Schweitzer Nov. 8, 1927 1,728,038 Burstyn Sept. 10, 1929 2,100,893 Anderson Nov. 30, 1937 2,272,752 Spurck Feb. 10, 1942 2,282,348 Thurmin May 12, 1942 2,405,606 Rawlins et a]. Aug. 13, 1946 2,414,786 Lincks et a1, Jan, 21, 1947

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