US2849570A - Short time delay defeater during closing stroke of circuit breaker - Google Patents

Description

Aug, 26, 1958 w. M. SCOTT, JR

.' SHORT TIME DELAY DEFEATER DURING CLOSING STROKE 0F CIRCUIT BREAKER 5- sneet-sheet 1 Filed July 22, 1954 N VEN TOR. MLL/HM .QvTr/e.

Aug. 26, 1958 w. M. SCOTT, JR 2,849,570 SHORT TIME DELAY DEFEATER DURING CLOSING STROKE 0F CIRCUIT BREAKER Filed July 22, 1954 r 5 Sheets-Sheet 2 Aug. 26, 1958 w. M. sco JR SHORT TIME DELAY DEFEA ER DURING CLOSING STROKE 0F CIRCUIT BREAKER Filed July 22,' 1954 5 Sheets-Sheet 3 INVENTOR. 40/11/40; fif- SZ'arrw/e.

m v m Aug. 26, 1958 w, sco T, JR 2,849,570

SHORT TIM DELAY DEFEATER DURING CLOSING S ROKE 0F CIRCUIT BREAKER Filed July 22, l9 54 5 Sheets-Sheet 4 IN V EN TOR.

M/lZ/l/W Earn/q wgy m 4 llTd/WYIZS Aug. 26, 1958 w. M. SCOTT, JR 2,849,570

SHORT TIME DELAY DEFEATER DURING CLOSING STROKE OF CIRCUIT BREAKER Filed July 22, 1954 5 Sheets-Shget 5 United States Patent 1 SHORT Til /IE DELAY DEFEATERDURING CLOS- lNG STRQKE F CIRCUIT BREAKER -William ML'Scott, Jr., Bryn Mawr, Pa., assignorto ll-T-E Circuit Breaker Company,,Pl1iladelphia, Pa, a corporation of Pennsylvania Application July 22, 1954, SerialNo. 445,124

6 Claims. ((21.1200-108) -trip-open when it is manually .or'automatically closed on a fault and is an improvement of the arrangement shownvain 'PatenttNo; 2,536,775,;iassigned to the assignee of the instant application.

Selective tripsystems such .as described inPatent No. '2;648.,802 and Patent No. 2,486,602, assigned touthe assignee of theinstant application; andareprovided iwith circuit breakersrof the type shown in Patent No. 2,439,165, assigned to the assignee-of the instant application, having ,time; delay characteristics, for allcurrentnvalues .up to the.,interrupting capacity of the circuit; breaker. Thus, the; circuit breaker always opens With'either long or short time 'delay characteristics.

These circuit breakers can properly. protect the system when :fault or short circuits occur and-are designed to selectively trip whenthese overcurrents occur. When the circuit breaker is securely latched in the closed position, the short and the long time; delay-tripping will .not harm the interrupter or the system duringv the period oftime'delay. However, if a faultexists on the line .atthe time when an-attemptisqmade to automatically .or;:n1anually close the circuit breaker, the circuit breaker may be severely damaged.

That is, the rnagneticxforces set up in the loop consisting ofthemovablecontact will'tend to-force; the contacts to their open, position andsincethis force may be larger than the force tending to. close the breaker,- the mechanisms will not be permitted to;latch closed.

Thus, if the circuitbreaker is provided with time delay characteristics, the trip free latch is not disengaged during .closing andhence, the circuit breaker is not'trip .free. That is, if the closing force is not-suificient to close and latch the contacts against the faultcurrent, thenthe opening of the breaker-will not be trip free.

It is, also noted that if the contacts do notlatch when the circuit breaker is closed ona fault current, the arcing contacts may remain in partial engagement and alternately. make .and break the controlled electrical circuits,

tion of the breaker if it is being automatically closed.

This undesirable condition cannot be satisfactorily overcome by merely providing more closing force to overcome the magnetic opening forces. The, reason for this is that the same closing: forces. are applied/whether or not a fault exists onthe line.

If sufficient closing :forces :were :provided to closeand latch the circuit breaker against the fault, then a closing operation withthissameforce, the;.absence 'of opposition forces established by.;a fault .current,:would cause undue mechanical :strain. on the breaker.

In order to overcome-this. undesirable condition, I

.have. provided a .pivotalmounting for themechanical delay timer mechanism .soxthatithisunit canbe: rotated to a freely rotatable position wheneverv the circuit breaker when the main .contactszhave. re-engaged and, the: circuit breaker isalatchedclosed'.v Thus, the circuit 'breakenhas instantaneous :trip. characteristics: :for ail imagnitudes 'of overcurrent only zduringithe closings-operation. *That is, when thetimervhousing iszrotatedito itszfreelytrotatable .:position, it; willznotqintroduce any atime delay in the ;event the: breaker jis 21010866. 1011 an overcurrent or fault. Thus, the circuit -breakernwillshaveihigh speed trip; characteristics during: the closing; period.

If thecircuit breaker is closed 011:3"110II1'12l1 line the timer housing isautomatically rotatedsand latchedsin its .operative position .SOjlIha-t the :circuittbreakenavillhave time delay: characteristics after the circuit; breaker -is latched closed.

With mynovel arrangement, ifian attemptis'made to close the interrupter on ;a fault.:.current-,the trip :latch will be released as .soon as .faultaacurrentmommences to flow even though the propv latch imayunot shave been moved to the fully latched position.

Thus, trip free operation -willoccur as .a-.-.resu;lt "of the instantaneousv tripping during, the- .closingoperation only. Thus, with. HIY IlOVEI' invention, there willrbe no sustained forces in'opposition to ,the manual--:closing means or to theautomatic .closingJmeans causing .-idam ageto the arcing contacts-asqa result of an '{attempted closing on a, faulted .line.

It will be noted that there are..severalz-other zmethods to achieve the above noted.desiredresults. For,example, copending application Serial No. 1445, 123,,v filed; Iuly.22, 1954, assigned'to thesass-igneevof, the instant application, provides an instantaneous armaturewhich zisnnorrnally blocked to prevent.QPeration thereof. ;;However,*"it is automatically unblocked during the ;opening .operation to permit instantaneous trip it the circuitbreakersis closed on a faulted. line.

Copending application Serial No. 445,094,,mfiled: July 22, 1954, assigned. to the Zassignee oi the instant; application, provides means, .operativelyconnected-i0 the.;circuit breaker and timer arm-..which will:remove,landimaintain the timer, arm from, the .path' of'movement oftthe-aitrip armature during the-period;{that,;the- -circuit hreakerpis opened and until .the.circ.u it .breaker is againilatched closed.

Copending ,applieationgserial No. #45 ,122, =,.fil6.d.f;];ll1y 22, 1954, assigned to the assignee of the instant, application provides, a;latch-for thelpivot of t-he timerzhousing which is, unlatched during the ;op ening;operation zsoethat the circuit breaker will trip free ,;.withoutztime-'delay,if

closed .on-a faulted line.

teristics due to the rotation and latching of the timer housing to an operative position.

Another object of my invention is the provision of an arrangement for a pivotally mounted timer housing so that it can be selectively positioned and latched depending on the position of the cooperating contacts of a circuit breaker.

Still another object of my invention is to provide an arrangement for a time delay circuit breaker wherein the entire timer housing is rotated by the opening of the circuit breaker to render the time delay means ineffective to thereby permit instantaneous tripping if the circuit breaker is closed on a fault.

These and other objects of my invention will be apparent from the following description when taken in connection with the drawings in which:

Figure 1 is an exploded perspective view of an operating mechanism of a circuit breaker and shows the cooperating contacts in a disengaged position. This Figure illustrates my novel device to rotate the pivotally mounted timer housing during the opening operation of the circuit breaker. In this arrangement, the timer housing remains in the freely rotatable position until the contacts are latched closed, at which time, the housing is rotated back and held securely in its operative position.

Figure 2 is a side View of the circuit breaker of Figure l and illustrates the position of the various components when the cooperating circuit breaker contacts are latched closed. This figure illustrates the manner in which my novel means latches the timer housing in the operative position so that subsequent automatic tripping of the circuit breaker will occur with time delay.

Figure 2a is a partial side view of the opposite side of the circuit breaker as seen in Figure 2.

Figure 3 is a schematic view of the circuit breaker of Figures 1 and 2 and illustrates the position of the various components when the circuit breaker is in the fully closed position of Figure 2. This figure illustrates .the latched position of the trip latch and prop latch.

Figure 4 is a schematic view of the circuit breaker of Figures 1 and 2 and illustrates the initial trip position.

Figure 5 is a schematic View of Figures 1 and 2 and illustrates the position of the various components when the circuit breaker is in the collapsed position, prior to the relatching of the trip latch.

Figure 6 is a schematic view of Figures l and 2 iilustrating the position of the components when the circuit breaker is in the fully open position of Figure l with the trip latch re-engaged.

Figure 7 is a semi-schematic view of the circuit breaker of Figures 1 and 2 and illustrates the position of the circuit breaker in the trip free position. This figure also illustrates the latched control relay and closing solenoid which comprises the automatic closing means for the circuit breaker. This figure further illustrates my novel means to render the escapement timing device ineffective until after the contacts have latched closed.

Figure 8 is a view in perspective, partially broken away, of the complete long and short time delayed trip armatures and control means thereof.

Figure 9 is a sectional View of the short time delay mechanism taken in the direction of the arrows 9-9 of Figure 11.

Figure 10 is a view, partially in section, of the short time delay mechanism taken in the direction of the arrows 1010 of Figure 9.

Figure 11 is a view, partially in section, of the short time delay mechanism taken in the direction of the arrows 1111 of Figure 9.

Figure 12 is a side view of the run off pinion and shaft of the short time delay mechanism of Figure 8.

Figure 13 is a side View of the run off assembly of the short time delay mechanism of Figure 9.

Referring to the figures, on the occurrence of an overcurrent condition, an energized coil 139, aided by the core 141 pulls the armature 142 against the bias of a spring (not shown). The armature 142 has a screw 145 threaded at one end thereof and which is used to efiect an adjustable contact with the initial tripping member 140. When coil 139 is energized above a predetermined valve of current, the head 144 of the screw 145' acts to rotate bar by hitting extension plate 146 which is bolted to the shaft 140. When the head 14-4 hits the end of the extension plate 146, the shaft 140 is caused to rotate in a counterclockwise manner looking from the right of the circuit breaker 30, which is the view of Figure l.

The speed of the armature 142 of the overcurrent trip coil 139 is controlled by the timer arm 5-136 which is pivoted on shaft 514 of the timer mechanism. The timer arm 5% is secured to the short time delay timer escapement mechanism which is identified by the numeral 73 in copending application Serial No. 254,348, filed November 1, 1951, and Serial No. 148,696, filed March 9, 1950, assigned to the assignee of the instant application.

The short time delay mechanism for the timer arm 5% may be identical to that described in the ab ve identified copending applications and forms no part of the instant invention.

However, a brief description of this unit will be given so that a complete understanding of how the rotation of timer mechanism and housing 73 during the closing operation of the circuit breaker serves to defeat the short time delay for the overcurrent trip armature 142.

Basically, the short time delay mechanism 73 shown in detail in Figures 8 through 13 inclusive, is a mechanical escapement mechanism having a verge 26 which controls the speed of rotation of the timer arm or lever 50%). Timer arm 51h bears against the lower extension of the short time armature 142 so that when the short time armature 142 moves from the fully open position of Figure 2 to the tripping position and before it completes its full trip movement (dotted view of Figure 2), it must rotate the timer arm 500 in a counterclockwise direction as the armature 14-2 is rotated in a clockwise direction.

The armature 142 cannot rotate toward tripping position without rotating the timer arm 5% in a counterclockwise direction. The escapement mechanism is in the short time delay housing 73 and secured to the timer arm 581) through the shaft 514. Hence, the escapement mechanism 73 controls the speed of movement of the armature 14-2 in its movement toward the trip position of the circuit breaker.

The escapement mechanism as seen particularly in Figures 9 to 13, is comprised of a housing 73, a shaft 5114 extending therefrom. The timer arm 500 is mounted on one end of the shaft 514. The other end of shaft 514 carries a segment gear 11 and a plate 12 (see also Figure 13). Segment gear 11 meshes with pinion 17 which is provided with a recess 13 (see also Figure 12) registering with the shrouding plate 12.

As the shaft 514 is turned, the segment gear 11, which meshes with the pinion 17, rotates pinion 17 until the segment gear 11 escapes from the pinion 17 The shrouding plate 12 is recessed at 14 below the level of the teeth of the segment gear 11 so that it does not interfere with the meshing engagement between teeth of segment gear 11 and the teeth of pinion 17.

After the desired value time delay has been achieved, it is advantageous that the armature escape the time delay mechanism. At this time, the shrouding plate 12, and particularly portion 16 thereof, comes into registry with the recess 13 of the pinion 17, thereby holding the pinion 17 stationary while the shrouding plate 12 and the shaft 514 may rotate readily With respect thereto.

The segment gear 11 is cut away at 18 so that it will not obstruct the movement of segment gear 11 at this run off position.

Consequently, the movement of the teeth of the segment gear 11 during the initial movement of the armature 142 5 is time-delayed thereby delaying'th'e 'rot'atio'nof thectime't" arm-500 and resultingin a time delay forthe tripping -I stroke of armature-1 42-. -HoWever,--when the armature reachesa partial value 'of'the total'strokeythe segment gear lldisengages tooth'engagementwith pinion 17 per/ 5 mitting an unrestrained strokeof the armature 142 to engagemith triggerwbar 1 46 with an impactblow.- I

In order to avoid misalignment between the'parts of the escapemerrt'niechanisinythe engagement of theraised portion 16 of the shronding plate 12 in the z'recess'lfi of 'the' pinion 17 holds-the pinion'17 'and'the'asso'ciated mecha nism -hereinatfter describe-din. the position' they held-at the tirnwthevteeth or gear segment 11 'leftpinion17 so that" during the return movement when teeth 1S engage -the pinion 17, thelrelationship between teeth 1'67, the- 'raised 15 portioh 16 "of shrouding plate 12 re-establishes mesh engagement'rof 'the".teeth ?of segmeht'gear -H and the teeth of pinion gear 17. 9

Thus; in order ito achieve the 'short time-delay it is necessary to selectively delay therotatio'n of "the pinion 2O 17. Pinion 17 is carried on shaft 19 whichearries-the"""' gear i20 tGe'tr Zll meshe's=-with -gear' 21- on shaft"22 which carrie's the 'gear' '34; -'-Gear 34 meshes with gear' 23 0m shaft 24 which carries the toothedescapement pinion 25. 25

Verge 26 rotatable on pin27 has opposite teeth28; 29 wh'iohialternately engages with-the teeth of escapement WheeI Y-LZS and limits 'its*spe'ed of r otation'by the speed with which the pinion Z8 and 29 of the verge 26 can successively escape-=the wheel 25 by oscillation of the verge- 26; The planesof =the teeth of the escapeme'nt wheel- 25 are so oriented that the direction" of theforce lines between wheel 25 and verge teeth -28 falls outside of v'erge pivots! by'a definiteamount; The resulting movemen 'causes the speed of oscillation of verge" 26 J to-valy in direct-proportion to themagnitude of the force impie'ssed on-it by pinion 25.

Thu's," as has been pointed out, the rotation of armature l42 t'o the 'trip position causes its lower extension to rotate fthe'timenleverfitltl of the short time mechanism 73 Which-is secured to the shaft fil l'and'which, through themechanisrnabove set 'for't-h,operates the timermechanism to effect short time delay in restraint of clockwise rotation of armature 1429" Th'greaterthe force executed 'by'armature 142, the 45 greater' thespeed of oscillation of verge 26 and the shorter the time-delay;

The enti're time delay housing 73is'mounted on a shaft- Whiclr-is in threaded engagement with threaded section 33 in W'alldS-bf the housing 73. The housing 73 may be rota-tablyadjusted wherein a greater or less number of teeth of the gear segment 11 must pass in engagement with the pinion 17, before the runoff condition is achieved wherein extension 16of the"shrouding plate 12 passed freely through the recess 13 of the pinion 17 While the recesslS in the gear segment 11 permits free-rotationof the gearsegrnent 11 past'the pinion 17.

The short time delay armature 142 is usedforthe-pun' pose of obtaining-a. short time delay expressedin cyclesfor currents exceeding a given minimum value.- This is in 0 contrast-to thedong timer-delay armature 42 ("Figure 8)- which is used for the purposeofobtaining a long time delay expressed-in seconds or minutes for current values in the recognized range of overcurrents; and also for the purpose of obtaining an instantaneous trip f-orshort circuit or other high values of faultcurrent.-

The i-nsta'nt--invention=is directedto meansto remove the timerwarrn' 500 from-the path of movement'of the"? overcurrent relay armature 142' during the manual or automatic!elosing 'of thecircuit breaker." Althoughthe cireuit ib'reakerper 'se, with whiclrmy novel arrangement I may hecoordinated 'formsno part of the instant inventiong a description of =the oper ationof the unit will now be giver'i orderto understand the cooperation between 6 the components of my-invention and-the operation of the- T circuit breaker.

The shaft is caused to rotate by means of the shunt trip coil -which--upon being energizedpulls anarmature-rnember-151 to it. The member 151 base link 152 rigidly attached to one-end of the memberdfil by A means of an angle 154. The li-nk152 is attached to the angle 154 by means of a threaded -portion--194 of link- 152 which enters the angle 1-54 anda nut148. --The angles 154 is movably attachedto the memberlSl by means' of a pin 155.- A restoring'spring147 attachedto them'enb her 151- resets the armature upon de-energizatiomof thew coil 150.

The link .152 is attachedto the shaft-140'by=mean's of another angle 156.- I The angle 156 is attached to -:t he-.- shaft 140 by means of bolts passing-throughmole 161-in angle 154 and shaft140 and to the-linklSZiby means of a cap 160. The cap is movably attaehed to the-link,- 152'. Thus; the -shaft=140can-now be caused to rotate by two methods-one due to the energizationof the over-- 1 current trip coil 139 and theotherdue to the-energizing--=- of the shunt trip coil 150. The coil 150 is remotely;- caused to be energized and is'usually"accomplished-by manual operation of a remote push-button switch. The rotationof shaft 140 causes a link-162 to be moved ---by means of an angle 163 which is bolted to the 'Sha'ft*-140."'- The angle 163 has an indentation- 165 near the farthest- I edge 166 fromthe shaft140: The'link162 haS-tWO"S10tS'- 168 and '167: The slot 167 =engagesx-the indentation-165 of angle 163.

The translatory movementof l-i-nk l62 oauses the rotation of a milled shaft-171). Theqnilled shaft- 170 has anwother angle 171 rigidlyattachedto it by means-of two-- bolts 172. This angle has an indentation 173 near the end 174 which-is farthest from the shaft-1-70.--The-indentation-173 of angle l7l engages 'theslot-168 of link--- 162. .Thus, the rotation of shaft-140causesithe rotation of milled shaft-171k. --.'When---milled--she-11 170 rotates to release a latch 177, as is hereinafter described, thecircuit breaker movable contacts 61 are-alloWed to be disengaged" from the stationary contacts 60:

The angle=171 described above'has-an-abutment -17S.-

This abutment-178 is engaged by a roller-179 'which'ds rotated manually by means-of the closing handle 1841 attached to 'theshaft 180.* Shaft--180 has acrank 181 which is rigidly attached to the shaftl tlby meansof a screw 182 The roller 179is attached'to one end of thecrank' 181s -When'=the 'shaft'180 =is rotatedbythe-closing-k. handle -1-84,-theroller :17 9 engages abutment :17 8 of angle 171 and rotated milled shaft 170. Thus rmilledshaftw-. 170 can'be-made to rotate by a pluralitycof .methodswto openthe circuit breaker: 30. It can bemade to rotate manually by means of closing handle 184; it can be made--- to rotate by Ineans of .an overcurrentcondition in -.trip coil 139 and it can be made-to rotate by means of an excitation of shunt trip 'coil 150,"as described above.

The --latchsurface 177 'is can integral partof trip arm 185. The latchsurface l77 engagesfthemilledshaft-170 so that a small revolutionof shaft 170lreleasesithetlatch 177, as hereinafter described, Thefshaft t17tli'is milled .1

6 slightly past center at 186, The trip arm-1851s pivoted at 187 on a longpin 188. T-he pin 188 is also engaged on the trip arm extension 189 atpoint 183. The movable arm 190 is pivoted on pin 188and extends beneath I a roller 193. The roller 193 is the'pi'vot' point of atog'gle 5 5 mechanism consisting of two links '194'and I95 'a'nd is a carried by a pin 202 which pivots. the meetin'g'of links 194"2ind 195 "which are "each comprised of two arms. Arms '194 are pivoted on fioatingpin 196 anda'rms 195 are pivoted on pin204.

The arms 194 support a rod 197 at 198 and 199;"1'espectively; The rod 197-carries one endof a restoring spring"203" which is tensed =by-'-'means of-. stationary" shaft "212. 3 p

The 'restoring' spr-ing-203 eicerts a tension-on the link: I 194 which tends to open or break-the toggle rnechanism.-'

Link 194 is pivoted on a floating pin 196 which is supported by link arm 185 and its extension 189 being parallel to the pin 188. The other link 195 of the toggle is pivoted on movable link 200 which is connected by means f an adjustable insulator 201 to the movable contact assembly 61 and pivoted on contact bar 406.

When the toggle mechanism consisting of links 194 and 195 is straightened out by means hereinafter described, pressure is put on movable link 200 by means of link 195 and bearing pin 204. The movable link 2530 is pinned to insulator 201 by pin 2G5 and moves so as to advance the insulator 201 and the movable contacts 61 towards. the stationary contact 60.

In the exploded View shown in Figure l, the contacts are open and the toggle mechanism consisting of links 194 and 195 is collapsed. The circuit breaker may be closed by a variety of methods. The circuit can be closed manually by means of shaft 180 rotated by closing handle 184, described above. If shaft 180 is rotated in the direction indicated by the arrow 1840, the roller 179 will engage the bottom of arm 190 and force the arm 190 against roller 193, thus straightening out the toggle mechanism and closing the circuit breaker contacts 61-60.

The movable links 200 are under an opening tension by means of opening spring 210 so that if no additional locking action other than described above for supporting the toggle existed, the circuit breaker would reopen immediately upon releasing the shaft 180. The locking device is supplied by means of a prop latch 211 which is located on a shaft 212 mentioned above, whose longitudinal axis is parallel to the axis of the milled shaft 17 0, and the rod 140. The prop latch 211 has two arms 213 and 214.

The latch surface 213 is located, when the circuit breaker is open, adjacent the roller 193. When the roller 193 is forced upward, as due to the pressure of arm 190, the roller pushes against prop latch 211 rotating the prop latch 211 on shaft 212. When the roller 193 has cleared the top of prop latch 213, the prop latch 213 snaps underneath the roller 193 due to the compression of biasing spring 220. The spring 220 which is wound on the shaft 212 has one end on an indentation 221 of crank 211, the other end borne against a shaft 222 which pierces the trip arm 185. The shafts 212 and 222 have been moved out of position in the exploded view for the sake of clarity. Actually, the shaft 222 pierces the trip arm 185 at point 207. The longitudinal axis of shaft 222 is essentially parallel to the longitudinal axis of shaft 212 and milled shaft 170.

When the roller 193 is moved, straightening the toggle, it causes the crank 211 to rotate compressing spring 220. The roller clears the top of prop latch 213 letting the crank rotate in the opposite direction until the prop latch surface 213 is directly beneath and supporting the roller 193. The other arm 214 of prop latch 211 bears against the shaft 222 preventing further rotation of the crank 211 so that the latch surface 213 is stopped directly beneath the roller 193. The spring 220 is under compression normally so that the arm 214 is constantly bearing against the shaft 222. When the toggle is straightened, the rotation of the prop latch 211 moves the arm 214 away from the shaft 222 until the roller 193 clears the top of prop latch 213. Then the reverse rotation of the crank 211 occurs until the arm 214 again bears against the shaft 212.

Thus, when the toggle is straightened and the circuit breaker closed, the prop latch 211 locks the toggle 194195 and thus locks the circuit breaker in a closed position.

The closing handle 184 by means of the shaft 180 after closing the circuit breaker by means of the rotation of roller 179 against the arm 190, as described above, is returned to its normal position by means of a crank 230. The crank 230 is pivoted on a stationary pin 231.

The crank 181 described above has an indentation 232 which meets a roller 233 of crank 230. The crank 230 supports pin 234 which has a restraining spring 235 engaged at one end 236. The restraining spring 235 is attached to an angle 237 and is tensed on the pin 236 causing the crank 230 to rotate. The rotation of crank 230 causes the roller 233 to meet the indentation, 232 returning the crank 181 to its normal position.

The various positions of the operating mechanism are shown in Figures 3 through 6.

Figure 3 shows the closed position thereof with link 195 pushed forward to raise the crank 200 and close the insulator 201 and contact arm 78 and with the roller 193 on the prop latch 213.

The latch arm 185 is shown in appropriate latching engagement with the milled shaft 170. When the shaft 180, described above, is turned to release the mechanism, or on the occurrence of tripping conditions, the milled shaft 170 is rotated to permit the latch arm 185 to move into the milled section 186 of the milled shaft 170, as seen in Figure 4.

Then, as seen in Figure 5, the roller 193 drops off the prop latch abutment 213 to open the circuit breaker.

Thereafter, as seen in Figure 6, the latch arm 185 is restored to its initial position and the milled shaft 170 is restored to its latching position so that the circuit breaker may again be manually moved from the open position of Figure 6 to the closed position of Figure 3 by handle 180.

The circuit breaker may also be automatically closed by means of the latched control relay having coil 300 and armature 301 and the closing solenoid 241 which controls the closing plunger 240.

The circuitry for the automatic closing means is shown in Figure 7 and the details of the latched relay and closing solenoid are seen in Figures 1 and 7. A detailed description of the operation of the closing means shown in these figures is set forth in copending applications Serial No. 254,349, filed November 1, 1951; Serial No. 383,714, filed October 2, 1953; Serial No. 423,782, filed April 16, 1954; Serial No. 428,638, filed May 10, 1954, all of which are assigned to the assignee of the instant application.

Figure 7 also illustrates the trip free operation of the circuit breaker. Thus, for example, when the breaker is 7 However, as heretofore noted, the breaker to which my invention is adapted is provided with an escapement type time delay for the operation of the armature 142.

Hence, if an attempt is made to either automatically close the breaker by means of the plunger 240 or manually close the breaker by means of the handle 184 on a fault line, the magnetic forces would tend to separate the cooperating contacts 60-61.

The opening magnetic forces on cooperating contacts 60-61 may be greater than the closing force which is derived from the energy flowing in the closing solenoid 241 or may be greater than the force derived when manually closing by handle 184. In this case, the circuit breaker contacts 60-61 will separate due to the magnetic forces, but the trip latch 186 will remain engaged since there is a time delay on the armature 142 which controls the position of the trip latch. It is also possible that only the arcing contacts of the circuit breaker will engage and remain in engagement since there is an insuflicient force to close the circuit breaker against a faultand thereby damaging these-contacts andthe circuit breaker. a

Hence, the componentswill tend to assume the-posh tion of Figure 3 except that'they will not-be moved.-

sufiicientlyas to cause prop latch 211to support-roller 193. However, since a closing force will be continuously applied, thereby driving the plunger 240'upwardly, -a second attempt will be made and theabove notedoperation will be repeated. Hence, there will be 1 chattering or pumping of the cooperating contacts which Will result in damage to the circuit breaker and line to be protected thereby.

Since the circuit is constantly being made-and-broken,

the armature 142 of the trip coil relay 139 will always be moved -back to its neutral position, as seen in Figur'e2. Thatflis, the current willnot be permitted to flow for sufficient length of time to allow'the armatur'e l42 to move from its energized position against the time delay 1 created by the-timer arm 500.-

It is a primary object of my invention to provide means whereby the timer-housing-73 'will be'rotated Whenever-the contacts 60,:61are moved fromengaged to disengaged position so that the timer arm 500 will not introduce any time delay in the movement of the trip armature 142-when the circuit breaker is closed on a fault line.

To'this endyI provide a shaft 533 which is in threaded engagement with the recess-33 of the timer housing; The shaft 533 is pivotally mounted in any desirable manner andforms the support for the timerhousing 73 and the' timer arm 500.

Theshaft 533 has a latch bracket531-rigidlymounted thereon The latch bracket 531" has twomembers 540:550 "extending perpendicularly therefrom and in a direction away from the housing 73. The member 540* is a shaft which extends past all of the poles of a circuit breaker "and'is the movabledrive for the latch bracket 531 'associatedwith each pole. The central'lever 507-i's pivotally mounted on a fixed pivot 510 and carries latcharm'532 which is pivotally mounted on lever-507 at 551.

The lever 507 has two protruding members- 552 553 In the position noted in Figure 2, the latch arm 532 latches the timer housing 73 "in the position indicated due to its engagement with stop pins 550 and 552. Hence, the biasing spring 538 is ineffective to rotate the timer housing:73.-' In the'position indicated; the timer mechanism in housing 73 is effective to delay the clockwise rotation of trip armature 142 in the manner heretofore described.

The lever 507 is controlled by the tie rod 502 which in turn is controlled through the bell crank 501. The bell crank 501 is rigidly mounted on contact bar 406 which has heretofore been described. The top of tie rod 502 is pivotally mounted at 504 on the leg 503 of bell crank 501. The other end of the tie rod 502 is pivotally mounted at 506 to the lever 507.

Hence, when the contacts 60, 61 are latched closed, the contact bar 406 will be in its extreme counterclockwise position thereby driving the tie rod 502 downwardly and hence holding the lever 507 in its extreme counterclockwise position.

Hence, in the position seen in Figure 2, on the occurrence of an overcurrent, the armature 142 would be attracted by the coil 139 and have to operate'against the timer arm 500 (dotted view in Figures 2 and 2a) thereby resulting in a time delay trip. When the contacts 60, 61 are moved from engaged to disengaged position, either by automatic trip 139 or shunt trip 150 or manual means 184,-the' contact bar-406 will rotate in a-clockwise=direction therebydriving the tie'rod 502 upwards.

This will cause lever 507 to rotate --aboutits fixed pivot 510 and thusmove thestopping pin away-from the latch arm 532. However, since'the entire timer housing 73 is biased in a counterclockwise direction by the spring- 538 and it's latch bracket 531 which rotateso as to main-- tain the pin 550 in sliding engagement with latch 532 and maintain the latch arm'532 in slidingeng-age-i ment with 1 stop pin 552.

Hence, when the contactsare in the-disengaged position,"the components will be in the-positionindicated in Figuredl. Thewentire housing 73 will have "been-:

rotated in a counterclockwise direction by thebia'sing rotatable position.

As seen in the trip free position of Figure 7, if the circuit breaker is closed on a fault line, the armature 142 will=instantaneously trip the circuit breaker since the" timer housing 73 has been rotated to .an inoperative posit-w tion so that the timer'arm 500 will not impede the move ment of armature 142.

If the circuit breaker is closed on a normalline'in which only normal current is flowing, it will be 'necessary to again rotate the time housing 73 in a clockwise direction so that it will be operative to delay any subsequent a utomatic ope'nings due to overcurrent'euergization of' trip coil 139.

Thus,'==as the contacts 60; 61 are moved-from discogaged position, either manually thruhandle 184 or by the automatic closing means, the contact bar 406-will be "rotated counterclockwise thereby lowering tie rod 502' causing counterclockwise rotation of lever 507.

contacts 60, 61 are latched closed, the tie r0d'502 is provided with a spring operated lost motion. The con-" struction is as follows: The tie rod 502 is comprised'o'f two members 560, 561 which are threaded on each end. The lower end of member 560 i's' in threaded engagement with member 562 which has a reduced cross-sectional extension 563. The upper end of member 561"h'as mem-' ber 564 in threaded engagement therewith.

spring 538.- 'Hence, the -timerarm1500; although :not rotated by lever 532, will no longerbe effective to delay the clockwise rotation'of the trip armature'142 due" to the-repositioning of timer-73 to the inoperative or freely.-

Member 564 has a center opening to receive the ex-" tension 563, Extension 563 carries a pin 565 which is guided into two side slots in member 564. A helicalspring 566 -is concentric with'the extension 563 and it; lodged'betweenthe support sections 567 and'568; respec tively, of members 562 and 564 Hence, when bell crank 501 drives the member 560 downwardly, the spring 566 will be compressed and the extension 563 and its pin 565 will be moved to the bot tom of the opening and slot, respectively, in member 564. Hence, the lever 507 will be driven partially counterclockwise.

The stored energy in compressed spring 566 will then drive the lever 507 to its extreme counterclockwise position of Figure 2. The system is disengaged so that the delay in the release of the energy of the spring 566 is sufficient to allow the contacts 60, 61 to latch closed. It will also be noted that by means of threaded members 560, 561, the effective length of the tie rod 502 can be adjusted after the unit is assembled in the circuit breaker.

It will be noted that in the usual installation of a circuit breaker of the type described to be used in a selective system is provided with two armatures, one of which is for long time delay and the other of which is for short time delay. As a rule, the long time delay is achieved by means of an oil displacement device and A the short time delay is achieved by means of an escapement mechanism.

The structural arrangement for the dual armature of the overcurrent coil and the time delay therefor is clearly set forth in copending applications Serial No. 148,696, filed March 9, 1950, and Serial No. 254,348, filed November l, 1951.

Since my invention is directed to the temporary defeat of the time delay, I have only shown the short time delay armature of the overcurrent coil. However, it will be understood that my invention is applicable to the dual time characteristic circuit breaker noted above.

In the foregoing, I have described my invention only in connection with preferred embodiments thereof. Many variations and modifications of the principles of my invention within the scope of the description herein are obvious. Accordingly, I prefer to be bound not by the specific disclosure herein but only by the appending claims.

I claim:

1. A circuit interrupter having a pair of cooperating contacts with an initial engaged, final engaged and a disengaged position; automatic trip means to effect movement of said contacts from said final engaged position to said disengaged position; a timer mechanism for said trip means to time delay the operation thereof; a single means to rotate said timer mechanism to a freely rotatable position when said contacts are moved to said disengaged position; said single means operatively connected to rotate said timer mechanism to an operative position when said contacts are moved past said initial engaged position to said final engaged position.

2. A circuit interrupter having a pair of cooperating contacts with an initial engaged, final engaged and a disengaged position; automatic trip means to effect disengagement of said contacts; a timer mechanism for said trip means to time delay the operation thereof; means to rotate said timer mechanism to an inoperative position when said contacts are moved to said disengaged position; said means operatively connected to rotate said timer mechanism to an operative position when said contacts are moved past said initial engaged position to said final engaged position; said means having a latch; said means operatively connected to said circuit breaker to latch said timer mechanism by said latch in said operative and in said freely rotatable positions.

3. A circuit interrupter aving a pair of cooperating contacts with an initial engaged, final engaged and a disengaged position, automatic trip means to effect disengagement of said contacts, a timer mechanism for said trip means to time delay the operation thereof; said timer mechanism contained within a housing, said housing having an operative position and an inoperative position to delay the automatic tripping of said circuit interrupter, a single means to selectively position said timer 12 housing to said inoperative position when said circuit breaker is in said disengaged and said initially engaged position; and to said operative position when said circuit breaker is moved to said final engaged postion.

4. A circuit interrupter having a pair of cooperating contacts with an initial engaged, final engaged and a disengaged position, automatic trip means to effect disengagement of said contacts, a timer mechanism for said trip means to time delay the operation thereof; said timer mechanism contained within a housing, said housing having an operative position and an inoperative position to delay the automatic tripping of said circuit interrupter,

means operatively positioned to selectively position said timer housing in accordance with the relation of said cooperating contacts to each other, said means having a latch; said means effective to latch said timer housing by said latch in said inoperative position when said circuit interrupter is opened by manual and automatic means, said means having a latch, said means effective to latch said timer housing by said latch in said operative position when said circuit interrupter moved past said initial engaged position to said final engaged position by manual or automatic means.

5. In a circuit breaker having a pair of cooperating contacts with an initial engaged, final engaged and a disengaged position, automatic trip means for said circuit breaker, a timer mechanism biased to inoperative position to permit instantaneous operation of said trip means when said circuit breaker is in said initial engaged position, means to rotate said timer mechanism against the force of said biasing means to render said timer mechanism operative to delay the operation of said trip means, said means operative to render said biasing means effective to rotate said timer to an inoperative position when the circuit breaker cooperating contacts are manually moved to said disengaged position.

6. In a circuit breaker having a pair of cooperating contacts with an initial engaged, final engaged and a disengaged position, automatic trip means for said circuit breaker, a timer mechanism biased to inoperative position to permit instantaneous operation of said trip means, means to rotate said timer mechanism against the force of said biasing means to render said timer mechanism operative to delay the operation of said trip means, said means operatively connected to said circuit breaker and operated When said circuit breaker is moved to past said initial engaged position to said final engaged position, said means operative to render said biasing means efiective to rotate said timer to an inoperative position when the circuit breaker cooperating contacts are manually moved to said disengaged position.

References Cited in the file of this patent UNITED STATES PATENTS 339,079 Scott Dec. 18, 1906

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