US2150584A

US2150584A - Circuit breaker

Info

Publication number: US2150584A
Application number: US209970A
Authority: US
Inventors: John B Macneill
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1938-05-25
Filing date: 1938-05-25
Publication date: 1939-03-14
Anticipated expiration: 1956-03-14

Description

6 Sheets-Sheet 1 INVENTOR ATTORN A HH IM J. B, M NEILL CIRCUIT BREAKER Filed May 25, 1938 March 14, 1939.

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l lll WITNESSES: 550%. M Wm March 14, 1939. J B, MacNElLL CIRCUIT BREAKER Filed May 25, 1938 6 Sheets-Sheet 2 2 INVENTOR E Ja/m-B. Mac/Veil].

4 BY 4 W ATTORN March 14, 1939. J. B. M NElLL C IRCUIT BREAKER Filed May 25, 1938 6 Sheets-Sheet 3 Z A m R H mm m w m m NM 6 March 14, 1939. J B, MacNElLL 2,150,584

CIRCUIT BREAKER Filed May 25, 1938 6 Sheets-Sheet 4 l ad fi fil. Job); 5. Wififizz March 14, 1939. J, B MacNEILL 2,150,584

CIRCUIT BREAKER Filed May 25, 1938 6 Sheets-Sheet 6 WITNESSES: INVENTOR 6 30M. J0/212 B Mac/Will @M M, BY

reamed Mar. 14, 1939 UNITED STATES PATENT OFFICE 2,150,584 cmcm'r enema I John B. MacNeill, Wilkinsburg, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application May 25, 1938, Serial No. 209,970 23 Claims; (01. 200-98) The invention relates to circuit breakers in" general and more particularly to operating mechanisms for circuit breakers.

' Another object of the invention is the provision of an operating mechanism as described above in which the means responsive to the condition of In the operation of circuit breakers it has been found desirable to provide for normally tripping a breaker which has been standing closed for some time by a non-trip free tripping means which will allow opening of the breaker only when the closing coil is deenergizedand which maintains the breaker under the immediate control of the closing coil. reclosed in the shortest possible time.

This permits the breaker to be However,

if the fault condition which caused the initial tripping of the breaker is still present when the breaker is reclosed it is important that the immediately succeeding tripping operation of the breaker be effected by a trip free tripping means which is capable of effecting opening of the breaker independently of the energized condition of the closing means in order to secure a high speed opening operation. One arrangement for accomplishing the above sequence of operations depends upon the use of two trip coils one for each of the two tripping means, and an electrical circuit transfer arrangement for normally placing the non-trip free trip coil under the control of the overload responsive relay, and for placing the trip free trip coil under the control of the overload relay for a predetermined period of time after the initial opening operation of the breaker.

An object of the present invention is the pro'-, v vision of an improved operating mechanism for securing high speed opening and closing operations of a circuit breaker.

Another object-of the invention is the provision of an operating mechanism for a circuit breaker which is operable to effect non-tripfree tripping of the breaker if a fault condition occurs when the closing means is deenergized, and trip free tripping of the breaker if the fault condition occurs when the. closing means is energized.

Another object of the invention is the provision of an operating mechanism for a circuit breaker embodying a trip free tripping means for effecting opening of the .breaker even though the closing means is in energized condition, additional nontrip free tripping means for effecting opening of .the breaker only when the closing means is deenergized but without releasing the operative connection of the breaker with the closing means, a single trip coil for operating either of the tripping means, and means responsive to the conditlon of the closing means for automatically selecting whichof the tripping means will operated by the single trip coil.

the closing means prevents operation of the trip free tripping means and permits operation of the non-trip free tripping means when the closing means is deenergized, and permits operation of the trip free tripping means when the closing means is in energized condition.

Another object of the invention is the provision of an improved operating mechanism for a circuit breaker as described above which is simple, reliable in operation, and inexpensive to manufacture.

' The novel features that are considered characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to structure and operation, together with additional objects and advan-' tages thereof will be best understood from the following detailed description of one embodiment of the invention when read in connection with the accompanying drawings, in which:

Figure 1 is an elevational view, partly in section, of a circuit breaker operating mechanism constructed in accordance with the invention, the mechanism being shown in closed latched position with the closing solenoid deenergized;

Fig. 2, is a fragmentary enlarged view of the mechanism shown in Fig. .1;

Fig. 3 is an enlarged plan view of the operating mechanism;

Fig. 4 is a fragmentary sectional view taken along the line IV--IV of Fig. 3 showing the trip coil and the rocking trip bar which selectively operates either of the two tripping latches of the mechanism; I

Fig. 5 is a partly schematic view of the operating mechanism and the breaker'showing the relative position of the parts immediately followinga tripping operation effected by the non-trip free latch;

Fig. 6 is a partly schematic view similar to Fig. 5 showing the position of the parts during a closing operation at the point when the arcing contacts of the breaker have just engaged;

Fig. 7 is a partly schematic view similar to Fig. 5 showing the position of the parts immediately following a tripping operation efiectedby the trip free latch, and

Fig. 8 is a schematic diagram'of an automatic reclosing circuit breaker system for controlling the circuit breaker and its operating mechanism.

Referring tothe drawings, the reference numeral 9 indicates generally a fabricated stel frame which may be constructed in any suitable manner to support the various parts of the circuit breaker operating mechanism.

A closing solenoid H is mounted on the lower portion of the frame 9 and comprises a movable core I3, a cooperating stationary core l5 and an operating winding which, when energized, pulls the movable core l3 downwardly to eflect a closing operation of the circuit breaker.

A lever mechanism of the trip-free type indicated generally at I9 is mounted on the upper portion of the frame in spaced relation to the closing solenoid I, and this mechanism serves to normally connect the circuit breaker with the closing solenoid. The lever mechanism comprises a closing lever 2| which is pivoted at its right hand end on the upper portion of the frame 9, and a breaker lever 23 which is pivoted at its left hand end to the free end of the closing lever 2|. The closing lever 2| consists of a pair of spaced parallel outer levers 25 (Fig. 3) which have their right hand ends pivoted about a com- 'mon axis by means of a pair of aligned pivot studs 2'! carried by two spaced vertical plates 29 which form a part of the frame 9. The breaker lever 23 consists of a pair of spaced parallel inner levers 3| which have their left-hand ends pivoted on a pivot pin 33 carried by and connecting the free ends of the outer levers 25. The inner levers 3| which form the breaker lever are spaced so as to be movable into the space between the outer levers 25 which form the closing lever. The right-hand end of the breaker lever 23 carries a trip free roller 35 which is mounted on a pin carried by and connecting the free ends of the inner levers 3|.

The circuit breaker which may be of any suitable construction is shown schematically in Figs. 5, 6 and 7 as comprising main stationary and arcing

contacts

31 and 39, and a movable bridging contact assemblage 4| which consists of a main bridging contact 43 for bridging the main stationarycontacts 31, and a pair of spring biased movable arcing contacts 45 for engaging the stationary arcing contacts 39. The arcing contacts are arranged to engage prior to engagement of the main contacts during closing of the circuit breaker, and to separate following separation of the main contacts during opening of the circuit breaker. The movable contact assemblage is carried by a rod 46 which is connected to the mid portion of the breaker lever 23 through the .agency of a pivoted lever 41 and an operating rod 49, the lower end of the operating pivotally connected to the breaker lever 23 by means of a pivot pin 5| which extends between the inner levers 3|. The circuit breaker is biased to open circuit position by an opening spring 53.

The breaker lever 23 is biased upwardly by the opening bias of the circuit breaker, and the trip free roller 35 carried by the free end of the lever 23 is normally engaged and releasably held in a position of alignment with the pivot axis 21 of the closing lever 2| by a trip free latching mechanism indicated generally at 55. When the trip free roller 35 is held in latched position, the breaker lever 23 is operatively connected to the closing lever 2| for movement thereby. The closing lever 2| is connected to the movable core II of the closing solenoid H by means of a pair of connecting links 51, and the free end of the closing lever is adapted to be releasably held in closed position as shown in Figs. 1 and 2 by means of a non-trip tree latch mechanism indirod 49 being the closing lever 23 and cated generally at 59- which engages a roller 6| carried by the pivot pin 33.

The closing lever 2| is biased in a clockwise direction about its fixed pivot axis 27 by means of a pair of retrieving springs 63 which are disposed between each of the outer levers 25 and an upper supporting plate of the frame 9.

When the trip free roller 35 carried by the free end of the breaker lever 23 is released by a releasing operation of the trip free latch mechanism 55, the operative connection between the circuit breaker and the closing lever 2| is released and the breaker is moved to open circuit position under the influence of its opening spring. The opening movement of the circuit breaker causes the breaker lever 23 to rotate in a counter-clockwise direct-ion toward the open position shown in Fig. 7 about the pivot pin 33 which is held down by the non-trip free latch mechanism 59. The breaker lever 23 during the final portion of its opening movement, effects an automatic releasing operation of the non-trip free latching mechanism 59 to cause release of the free end of the closing lever 2|. For this purpose the breaker lever 23 is provided with a projecting pin 65 adjacent its pivoted end which, during a portion of the opening movement of the lever 23, engages and rotates a pivoted bell crank releasing lever 61 to effect release of the non-trip free latching mechanism 59 and consequently the free end of the closing lever 2|. When the free end of the closing lever 2| is thus released, the retrieving springs 63 rotate the closing lever in a clockwise direction about its pivot axis 21, and since the pivot pin 5| which connects the breaker operat ing rod 49 with the breaker lever 23 becomes stationary when the breaker reaches open position, the clockwise rotation of the closing lever by the retrieving springs effects a clockwise rotation of the breaker lever 23 about the pivot pin 5| as a center to return the trip free roller 35 into latching engagement with the trip free latch mechanism 55. At this point the two levers 2| and 23 are in the position shown in Fig. 5 and since the trip free roller is relatched by the trip free latch mechanism 55, the breaker lever 23 is again operatively connected to the closing lever 2| and through the same to the movable core l3 of the closing solenoid. When the closing solenoid H is energized. the two levers 2| and 23 are rotated in a counterclockwise direction about the common axis of the pivot studs 21 and the trip free roller 35 to the closed position shown in Figs. 1 and 2 to effect closing of the circuit breaker. When the two levers reach the closed position the non-trip flee roller 6| carried by the pin 33 is re engaged and-latched by the non-trip free latch mechanism 59. a

The circuit breaker may also be tripped open by a releasing operation of the non-trip free latching mechanism 59. A releasing operation of the non-trip free latch mechanism allows the circuit breaker to be moved to open position by its opening spring and this movement causes the two levers 2| and 23to rotate in a clockwise direction about the common axis of the pivot studs 2'! and the trip free roller 35 to the open position shown in Fig. 5. In this instance. however, the circuit breaker remains operatively connected to through the same to the movable core of the closing solenoid I so that the breaker can be immediately reclosed by energizetion of the closing solenoid The trip free latch mechanism 55 (Fig. 2) 001m prises a main latch member 69 pivoted on a pivot pin II carried by a part of the frame and is biased by means of a spring I3 to a latching position in which it engages and restrains the trip free roller 35 in the position shown in Fig. 2. A block 15 carried by the frame serves as a seat for one end of the latch spring I3, and this block is provided with a surface I! which forms a stop to prevent movement of the latch 69 beyond its latching position. In order to hold the latch 69 in.latching position against the upward bias exerted on the breaker lever 23, a secondary auxiliary latch I9 is provided. The latch I9 is pivoted by means of a pin 8| carried by a portion of the frame and is biased to latching position by means of a light spring 83. The nose of the latch I9 is provided with a substantially right angled notch for engaging the upper corner of the main latch 69. The auxiliary latch I9 in latching position effectively locks the main latch 69 in its latching position. The auxiliary latch I9 is adapted to be moved in a clockwise direction about its pivot axis 8| to effect a releasing operation of the latch mechanism by a tripping means which will be hereinafter described.

When the auxiliary latch I9 is released, the trip free roller 35 moves upwardly forcing the main latch 69 in a clockwise direction until the roller 35 clears the nose of the latch. The spring I3 then returns the main latch 69 to latching position. The main latch 69 is provided with a rounded nose to allow the roller 35 to force the latch back and clear the same during resetting or retrieving of the breaker lever 23. As soon as the trip free roller 35 has cleared the nose of the latch 69 during a retrieving operation, the spring 13 returns the latch 69 to latching position and the auxiliary latch 19 returns to its latching position to engage and hold the main latch 69.

ing the breaker lever 23, there is provided a holding lever 81 pivoted on the pivot pin BI and biased in a clockwise direction by a spring 89 which is slightly stronger than the latch spring 83. The lever 81 isprovided with an extending arm 9| which lies in the path of the final retrieving movement of the free end of the breaker lever 23. When the trip free roller is in latching position the free end of the breaker lever 23 holds the lever 81 down in an inoperative position to allow .the auxiliary latch I9 to assume its latching position. However, when the trip free roller moves upwardly following a tripping operation by the latch mechanism 55, the holding lever 81 rotates; in a clockwise direction, and a cross pin 93 carried thereby engages and holds the auxiliary latch 19 in its released position until the trip free roller has been retrieved to its latching position.

The non-trip free latch mechanism 59 is substantially similar to the trip free latch mech-- anism previously described. The latch mechanism59 comprises a main latch pivoted on a pin 91 carried by part of the frame and is biased r by means of a spring 99 to latching position in ried by the closing lever 2|. A block I9| carried by the frame serves as a support for. one end of the spring 99 and is provided with a stop surface I93 for preventing movement of the. latch 95 beyond its latching position. The main latch 95 is held in latching position by means of an auxiliary latch I95. The auxiliary latch I95 is in the form of a bell crank lever pivoted on a pin I91 carried by a portion of the frame and the latch is biased to latching position by means of a light spring I99. provided with a substantially rectangular notch III for engaging the upper corner of the main latch 95 to lock the main latch in latching position. The main latch 95 is provided with a rounded nose to permit it to be forced back and cleared by the non-trip free roller 6| during closing movement of the closing lever 2|. In order to permit the closing lever 2| to be moved to its completely closed position and to be relatched by the latch mechanism 59, there is provided a holding lever 3 which is similar to the'holding lever 81 of the trip free latch mechanism 55. The holding lever I I3 is pivoted on the pin I91 and is biased in a counter-clockwise direction by a spring II5 which is slightly stronger than the latch spring I99. The lever H3 is provided with an extending portion II! which extends intothe path of the final closing movement of the free end of the closing lever 2|. When the closing lever 2| is in the closed position shown in Figs. 1 and 2, the lever II3'is held down in. an inoperative position to permit return of the auxiliary latch I 95 to latching position. However, when the free end of the closing lever moves upwardly following a tripping operation of the latch member 59, the holding lever I I3 rotates in a counterclockwise direction and a projection I29 carried thereby engages and holds the auxiliary latch I95 in released position clear of the main latch 95 I until the closing lever 2| has been returned to the fully closed and latched position by the closing solenoid II.

Both of the latching

mechanisms

55 and 59 are adapted to be operated by a single trip coil H9. The trip coil H9 is mounted on a portion of the frame beneath the trip-free latch mechanism 55 and is provided'with a trip plunger I2I. adapted to be energized in response to predetermined overload conditions in the circuit controlled by the breaker to cause upward movement of the trip plunger I2 I. A rocking trip bar I23 (Figs. 3 and 4) rests freely on a plate I 25 carried by the frame above the trip coil H9. The

plate I25 is provided with an opening I21 for receiving the upper end of the trip plunger I2I and with suitable guides I29 for guiding the trip bar I23 and for preventing longitudinal and lateral displacement thereof. The trip plunger I2 I, when moved upwardly, engages the under side of the trip bar I23 to cause rocking movement of the bar about whichever end is free to move. The auxiliary latch I9 of the trip free latch mechanism 55 is disposed over one end of the trip bar I23 and the upper free end I 3| of a pivoted bell crank lever I33 is disposed over the opposite end of the trip bar I23. The bell 'crank' lever I33 is pivoted intermediate'its ends on a pivot pin I35 carried by the frame 9 and the lower endof the bell crank lever is pivotally connected by means of a pivot pin I31 to the right-hand end of a horizontal connecting link I39. The lefthand end of the connecting link I 39 engages the The operating winding of the trip coil is.

The nose of the latch I95 is lower or vertical arm of the auxiliary latch I95 ":5

through the agency of a pin and slot connection Ill,

I! the trip plunger I2I is moved upwardly at a time when the bell crank lever I33 is prevented from moving in a counter-clockwise direction, the

upward movement of the trip plunger I2I will cause the rocking trip bar I23 to rock about its end which engages the free end I3I of the bell crank lever I33 to eilect upward movement of the auxiliary latch 19 to cause release of the trip tree latch mechanism 55. On the other hand, if the trip plunger I2I is moved upwardly at a time when the auxiliary latch 19 is prevented from moving in a clockwise direction, the upward movement of the plunger I2I causes the rocking trip bar I23 to rock about its end which engages the auxiliary latch 19 to efiect counterclockwise rotation of the bell crank lever I33. The counter-clockwise rotation of the bell crank lever I33 moves the horizontal connecting link I39 towards the right and rotates the auxiliary latch I05 in a counter-clockwise direction to effect release of the non-trip free latch mechanism 55. If neither the bell crank lever I33 or the auxiliary latch 19 are held against movement the upward movement of the plunger I2I effects release oi both the trip free and the non-trip free latch mechanisms.

If an overload condition occurs in the circuit controlled by the breaker when the breaker has been standing closed and the solenoid deenergized for a suflicient length of time for the residual flux to have died down to a point where there is sub stantially no flux present in the solenoid, it is desirable that the circuit breaker be tripped by means of the non-trip free latch mechanism 59 because when the breaker is tripped by the nontrip free latch mechanism 59 it is moved to open circuit position without releasing the operative connection between the breaker and the closing lever or solenoid. This permits the circuit breaker to be reclosed in the shortest possible time. The closing solenoid may be arranged to be energized substantially simultaneously with the trip coil so that it will have developed sufiicient tlux to halt opening movement of the breaker andbegin to reclose the breaker as soon as the arcs drawn between the contacts of the breaker have been extinguished, without allowing the breaker to continue to the full open circuit position.

However, if the overload condition occurs at a time when the solenoid is in energized condition or when there is still some residual flux present in the solenoid, it is important that the breaker be tripped open by means of the trip free latch mechanism 55 in order to permit high speed opening of the breaker unretarded by any opposing force or magnetic drag of the closing solenoid II.

In order to provide for tripping of the breaker by the proper latch mechanism in accordance with the condition of the closing solenoid there is provided a means responsive to the condition of the closing solenoid for automatically selecting which of the two

latch mechanisms

55 and 59 will be operated by the operation of the trip coil II9. For the purpose of distinguishing between the energized and deenergized conditions of the closing solenoid II, there is provided a lost motion connection between the movable core I3 and the closing lever 2|. The connecting links. 51 are provided .with aligned slots- I45 which engage projecting studs I51 carried by the closing lever 2I. The movable core I3 and the links 51 are biased upwardly by means of a pair of tension springs I to cause the lower ends 01' the slots I55 to engage the projecting studs I51 carried by the closing lever 2I when the solenoid is deenergized. The springs I49 have their lower ends connected to the upper ends of the connecting links 51 and their upper ends connected to projecting pins I5I carried by the closing lever 2I. When the closing solenoid is completely deenergized, the springs I59 maintain the movable core I3 in a slightly raised position with the lower ends of the slots I45 of the links 51 in engagement with the projecting studs I41 carried by the closing lever 2| as shown in Figs. 1 and 2.

One of the links 51 carries a pin I53 adapted to engage one arm I55 or a bell crank lever I51. The bell crank lever I51 is pivoted on a pin I59 carried by the frame 9 and its other arm I5I engages the lefthand end of a rod I53 through the agency of a pin and slot connection I55. The rod I53 is supported for horizontal movement by suitable guides carried by the frame 9 and the pin and slot connection I55 permits straight line movement of the rod I63 when the bell crank lever I51 is rotated. The right-hand end of the horizontal rod I63 is connected by a link I51 with a pivoted holding latch I69. The latch IE9 is pivoted at its lower end on a pin I1I carried by the frame 9 and its upper end is adapted to engage a projection I13 carried by the auxiliary latch 19 of the trip iree latch mechanism to prevent releasing movement of the auxiliary latch 19 when the holding latch IE9 is in latching position. The horizontal rod I63 is biased towards the left as viewed in Figs. 1 and 2 by means of a spring I15. The spring I15 serves to bias the latch I59 to latching position, and the bell crank lever I51 clockwise.

An interlock projection I11 is carried by one of the links 51 and this projection is adapted to engage a projection I19 carried by the horizontal rod I39 to prevent right-hand movement of the link I39 and counterclockwise movement 01! the bell crank lever I33 when the movable core I3 is in the down or breaker closed position and the sole- 'noid I I is energized.

When the movable core I3 of the solenoid II is in the down or breaker closed position and the solenoid is in'energized condition or has any substantial magnetic flux present therein, the pin I53 carried by the link 51 maintains the bell crank lever I51 in the position shown in Fig. 6 to maintain the holding latch I69 in released position clear of the latch 19, so that the trip free latch mechanism 55 is free to be operated by the trip coil. In the position of the parts shown in Fig. 6 the breaker has not been completely closed and the latch mechanism 59 is still in the released position to permit relatching of the roller 5 I. In this position of the parts the mechanical interlock projection I11 also engages the projection I15 on the horizontal rod I39 to prevent counterclockwise movement of the bell crank lever I33, so that if the trip plunger is moved upwardly under these conditions it will cause the rocking trip bar I23 to move the auxiliary latch 19 to released position to effect a tripping operation of the breaker by means of the trip tree latch mechanism 55. The projecting pin I 53 carried by the link 51 is so disposed that during a closing operation of the breaker by the closing solenoid II it engages and moves the bell crank lever I51 in a. counter-clockwise direction to eflect release of the holding latch I69 at a point just before the arcing contacts of the breaker engage, so that the breaker is free to be tripped by the trip free latch mechanism 55 from this point of the closing movement on to the fully closed position.

When the closing solenoid is deenergized and there is substantially no residual flux in the solenoid the springs I49 move the movable core I3 and the links 51 to the slightly raised position shown in Figs. 1 and 2. This upward movement of the links 51 allows the spring I to rotate the bell crank lever I51 in a clockwise direction and to move the holding latch I69 to its latching position in holding engagement with the auxiliary latch 19 to the trip free latch mechanism. The slight upward movement of the link 51 also causes the mechanical interlock projection I11 to move out of the path of the projection I19 on the horizontal rod I39 so that the rod I39 is free to move towards the right. If an overload occurs under these conditions, that is, with the solenoid deenergized and the links 51 in their slightly raised position, the upward movement of the trip plunger I2! will cause the rocking trip bar to rock about its end which engages the auxiliary latch 19 and effect counter-clockwise rotation of the bell crank lever I33. The counter-clockwise rotation of the bell crank lever I33 rotates the auxiliary latch M5 to its released position to effect a tripping operation of the breaker by the non-trip free latch mechanism 59.

The pin and slot connection MI between the left-hand end of the horizontal link I39 and the .vertical leg of the auxiliary latch I05 serves to allow the auxiliary latch I05 to be moved automatically to released position by the releasing bell crank lever 61 during the upward movement of the breaker lever 23, and also allows the latch N15 to be held in released position by the holding lever II3 during closing of the breaker even though the horizontal link I39 may be prevented from moving to the right by the interlock projection I11.

The interlock projection I11 is provided with a beveled lower edge so that during a closing operation of the breaker the interlock projection I11 engages and moves the horizontal rod I39 by a cam action slightly to the left at a point before the arcing contacts engage so that the free end I3I of the bell crank lever I33 is returned and held in engagement with the end of the rocking trip bar I23.

The operation of the circuit breaker and mechanism is briefly as follows: If an overload condition occurs when the mechanism is'in the position shown in Figs. 1 and 2, that is, with ,theclosing solenoid II deenergized and the movable core I3 and the links 51 in the slightly raised position, the upward movement of the trip plunger I2I effects release of the non-trip free latch mechanism 59 and the free end of the closing lever 2I. The breaker moves to open circuit position under the infiuence'of its opening spring and the two levers 2I and 23-are rotated to the position shown in Fig. 5, the breaker remaining operatively connected to the movable core I3 of theclosing solenoid. When the closing solenoid is energized the two levers 2| and 23 are rotated in a counterclockwise direction about the common pivot axis of the studs 21 and the trip free roller 35 which is held latched to the closed position shown in Figsl' 1 and 2, to effect closing of the circuit breaker. During the closing operation, the mechanical interlock projection I11 engages the projection I19 on the horizontal link I39, and the pin I53 carried by the link 51 engages and moves the bell crank lever I51 in a counter-clockwise direction to effect movement of the holding latch I69 to released position, both operations taking place just prior to engagement of the arcing contacts.

If the fault condition causing the overload is still present at the time the circuit is completed, the trip coil II9 will again be energized and the trip plunger moved upwardly to effect release this time of the trip free latch mechanism 55 and the trip free roller 35 before the closing lever 2| reaches closed latched position. The release of the trip free roller 35 immediately releases the operative connection between the breaker lever 23 and the'closing lever 2i and the circuit breaker moves to open circuit position under the influence of its opening spring independently of the energized condition of the closing solenoid. The breaker lever 23 is moved in a counter-clockwise direction about the pivot pin 33 and during a portion of its opening movement causes the projecting pin \65 to rotate the releasing bell crank lever 61 to effect release of the non-trip free latch mechanism 59. When the non-trip free latch mechanism 59 is released the retrieving springs 63 rotate the closing lever iii in a clockwise direction about the pivot axis 21 to cause the breaker lever 23 to be rotated in a clockwise direction and return the trip free roller 35 in latching engagement with the trip free latch mechanism 55. The energization of the-closing solenoid II then rotates both of the levers 2I and 23 in a counter-clockwise direction about the pivot axis 21 to closed position to effect closing of the circuit breaker. If the fault condition causing the overload has in the meantime been cleared the free end of the closing lever moves to the fully closed position and is relatched by the non-trip free latch mechanism 59 and the breaker remains closed.

Fig. 8 illustrates diagrammatically a suitable reclosing circuit breaker system for controlling the circuit breaker operating mechanism. The operating mechanism previously described with the trip coil H9, and the closing solenoid II has been indicated schematically as contained in a casing indicated by the rectangle I80. The reference numeral I8I indicates a supply circuit which is arranged to be connected to a load circuit I83 by the circuit breaker 4|. A fault responsive relay I85 is connected so as to be energized in accordance with the current flowing through the circuit breaker 4|. When the current supplied to the load circuit exceeds a predetermined value the overload relay I85 is arranged to effect energization of the trip. coil II9 if the circuit breaker is closed. Also the overload relay I85 initiates the closing operation of the circuit breaker before it has completed itsopening operation. This result is obtained by having the relay I85 complete an energizing circuit or instantaneous reclosing circuit for a closing control relay I81 which in turn completes an energizing circuit for the closing coi1'I1.

In order to limit the number of instantaneous reclosures of the circuit breaker to a predetermined number, which, in the arrangement shown, is one, a lookout relay I89 to provided which, after the initial 'reclosure, maintains the instantaneous reclosing circuit previously described for the relay I81 which is completed by the overload relay I85, open for a predetermined time interval if the circuit breaker remains closed, and maintains the instantaneous reclosing circuit permanently open if the circuit breaker is open at the expi3ation of the predetermined time interval. As shown, the operating coil I9I of this lockout relay I89is connected in series with the closing coil I1. The operating coil I when energized opens the circult of the relay I81 which is completed by the overload relay I85 so that a subsequent operation of the relay I 85 does not effect the immediate energization of the relay i81. The relay I89 is arranged in any suitable manner so that it is held in its energized position after the operating windlng I9I is deenergized. In the arrangement shown this result is obtained by means of a latch I93 which holds the relay in energized position and which is arranged to be released by a release coil I95 when the coil I95 is energized.

There is also provided additional automatic re closing means of any suitable type, examples of which are well known in the art, for effecting the reclosing of the circuit breaker a predetermined number of times with relatively long time inter vals between successive reclosures in case the circuit breaker does not remain closed after the initial reclosure thereof, and also for eifecting energization of the release coil I95 if the circuit breaker is closed after the automatic reciosing means I91 has been in operation for a predetermined period of time. The automatic reclosing means for accomplishing the above purpose may be similar to the automatic reclosing means disclosed in Patent No. 1,786,324 granted to R. J. Wensley December 23, 1930, and assigned to the assignee of the present invention.

The operation of the system described above is briefly as follows: Under normal load conditions the circuit breaker remains closed and the control devices are in the positions shown. When an overload occurs the overload relay I85 closes its contacts I99 to complete a circuit through the auxiliary contacts 211i on the closed circuit breaker for energizing the trip coil II9 to effect opening of the breaker by the non-trip free latch mechanism 59 of the operating mechanism as previously described, if the closing solenoid II is in completely deenergized condition with substantially no flux present therein at this time. At the same time an energizing circuit is completed for the closing relay I 81 through the contacts 203 of the relay I85 and the contacts 285 of the lockout relay I89. By closing its contacts 201 the relay I81 completes a series energizing circuit for the closing coil I1 of the circuit breaker and the operating winding I9I of the lookout relay I89. The energization of the closing coil I1 closes the circuit breaker in the manner previously described in connection with the description of the operating mechanism. The energization of the relay I 89 causes this relay to open its contacts 205 to prevent a subsequent energization of the overload relay I 85 from eifecting a substantially instantaneous reclosure of the circuit breaker.

The closing of the auxiliary contacts 288 on the circuit breaker in response to the initial opening thereof completes a starting circuit 289 for the.

automatic reclosing means I 91. If the fault conditlon is still present at the time the circuit breaker is reclosed, i. e., when its arcing contacts engage, the overload relay I 85 again closes its contacts I99 to energize the trip coil H9 so that the circuit breaker is tripped open again, this time by the trip free latch mechanism since the closing solenoid is still energized. The closing of the contacts 203 at this time does not close the instantaneous reclosing circuit for the closing control relay I81 because this circuit is now open at the contacts 205 of the lookout relay.

After the second opening of the circuit breaker a time interval elapses before the automatic reclosing means I91 completes a closing circuit 2H for the closing relay I81. When this closing circuit III is completed, relay I81 by closing its contacts 201 completes an energizing circuit for the closing coil I1 in the manner previously described to eifect another closing of the breaker. If the fault is still connected to the load circuit so that the trip coil I I9 is again energized to effect the immediate opening of the breaker, the automatic reclosing means I91 is arranged in a manner well known in the art to effect a predetermined number of energizations of the control relay I81 with predetermined time intervals between successive energizations. If the circuit breaker fails to remain closed after said predetermined number of reclosures, the reclosing means I91 is rendered inoperative in a manner well known in the art, to effect further energize.- tion thereof and the breaker remains open. If, however, the circuit breaker is closed after the automatic reclosing means I91 has been in operation for a predetermined time, it effects in a well known manner the energization of the release magnet I95 which releases the latch I93 and restores the lockout relay I89 to its normal position so that the instantaneous reclosing circuit is again rendered operative to control reclosure of the breaker. I

It will thus be seen that the invention provides an operating mechanism for a circuit breaker which includes a trip free tripping means for efiecting opening of the breaker even though the closing means is in energized condition and additional non-trip free tripping means for effecting opening of the breaker only when the closing means is deenergized but Without releasing the operative connection between the breaker and the closing means, a means operable in response to predetermined overload conditions for operating the two tripping means, and a means responsive to the condition of the closing means for preventing operation of the trip free tripping means and permitting operation of the non-trip free tripping means when the closing means is in deenergized condition, and for permitting operation of the trip free tripping means when the closing means is in, energized condition. The invention provides a mechanism which permits the circuit breaker to be reclosed in the shortest possible time if the overload condition which causes tripping of the breaker occurs when the closing solenoid is in deenergized condition, and yet which secures a high speed opening of the breaker unretarded by any opposing force or magnetic drag of the closing means if the'overload occurs when the closing means is in energized condition.

While the invention has been disclosed in accordance with the provisions of the patent statutes, it is to be understood that various changes in the structural details thereof may be made without departing from the spirit of the invention. It is desired, therefore, that the appended claims be given the broadest reasonable interpretation permissible in the light of the prior art.

I claim as my invention:

1. In a circuit breaker, closing means for said breaker, tripping means for effecting opening of said breaker independently of the condition of said closing means, additional tripping means for effecting opening of said breaker only under certain conditions of said closing means, a single trip coil operable in response to predetermined conditions to operate either of said tripping means and means responsive to the condition of said closing means for selecting which of said tripping means shall be operated by said trip coil.

2. In a circuit breaker, electrical means for closing said breaker, tripping means for effecting opening of said breaker irrespective of the electrical condition 01' said closing means, additional tripping means for effecting opening of said breaker only when said closing means is deenergized, a single trip coil operable in response to predetermined conditions to operate either 01' said tripping means, and means responsive to the electrical condition of said closing means for automatically selecting which of said tripping means shall be operated by said trip coil.

3. In a circuit breaker, electromagnetic closing means for said breaker, tripping means for effecting opening of said breaker independently of the energized condition of said closing means, additional tripping means for eifecting opening of said breaker only when said closing means is deenergized, a single trip coil operable in response to predetermined conditions to operate either of said tripping means, and means responsive to the energized and deenergized conditions of said closing means for automaticallyselecting which of said tripping means will be operated by said trip coil.

4. In a circuit breaker, electromagnetic closing means for said breaker, tripping means for effecting opening of said breaker independently of the energized condition of said closing means, additional tripping means for effecting opening of said breaker only when said closing means is deenergized, a single trip coil operable in response to predetermined conditions to operate either of said tripping means, and means responsive to the condition of said closing means for placing only said additional tripping means under the control of said trip coil when said closing means is in deenergized condition, and for placing said first-mentioned tripping means under the control 01' said trip coil when said closing means is in energized condition.

5. In a circuit breaker, electromagnetic closing means for said breaker, tripping means for e!- fecting opening of said breaker independently of the energized condition ofsaid closing means, additional tripping means for eii'ecting opening of said breaker only when said closing means is deenergized, a single trip coil operable in response to predetermined conditions to operate'either of said tripping means, and means responsive to the condition oi said closing means for causing only said additional tripping means to be operated by said trip coil upon the occurrence of predetermined conditions when sald closing means is in deenergized condition, and for causing said firstmentioned tripping means to be operated by said trip coil upon the occurrence of predetermined conditions when said closing means is in energized condition.

6. In a circuit breaker, a solenoid having a moving core for closing said breaker, tripping means for effecting opening of said breaker irrespective of the position ofsaid core, additional tripping means for eflecting opening of said breaker only when said solenoid is deenergized,

a single trip coil operable in response to pre determined conditions to operate. either of said tripping means, .and means responsive to the position of said core for automatically selecting which of said tripping means shall be operated by said trip coil.

7. In a circuit'breaker, means for closing said breaker, a first latch releasable to cause opening of said breaker independently of the condition of said closing means, a second. latch releasable to cause opening oi said breaker oniy under certain conditions of said closing means, a single trip col] operable in response to predetermined conditions to release either of said latches and means responsive to thecondition of said closing means for automatically selecting which of said latches shall be released by said trip coil.

8. In combination, a circuit breaker biased to open circuit position, operating mechanism for said breaker comprising an electromagnetic means for closing said breaker,,a first latch releasable to effect opening of the breaker independenty of the energized condition of said closing means, a second latch releasable to eifect opening of said breaker only when said closing means is in deenergized condition, a single trip coil having a plunger operable in response to predetermined conditions to effect release oi. either of said latches, and means responsive to the condition of said closing means for placing said second latch only under the control of said trip coil when said closing means is in deenergized condition, and for placing said first latch under the control of said trip coil when said closing means is in energized condition.

9. In combination, a circuit breaker biased to open circuit position, means for closing said breaker, a first latch normally and releasably connecting said breaker to said closing means, a second latch for releasably holding said breaker in closed circuit position while it remains connected to said closing means, tripping means comprising a single trip coil operable to release either of said latches, and means responsive to the condition of said closing means for automatically selecting which of said latches will be operated by said trip means.

10. In combination, a circuit breaker biased to open circuit position, electromagnetic closing means for said breaker, a first latch normally and releasably connecting said breaker to said closing means, said latch being releasable to eflect opening of said breaker independently of the en- .ergized condition of said closing means, a second latch for releasably holding said breaker in closed circuit position while it remains connected to said closing means, tripping means operable in response' to predetermined conditions to release either of said latches, and means responsive to the condition of said closing means for causing said second latch only to be released by said tripping means in response to said predetermined conditions when, said closing means is in deenergized condition, and for causing said first latch to be released by said tripping means in response to said predetermined conditions when said closing means is in energized condition.

llwIn combination, a circuit breaker, operating mechanism tor saidcircuit breaker comprising closing means for said breaker, tripping means for effecting opening of said breaker inmeans for effecting opening of said breaker independently of the energized condition of said closing means, additional tripping means for effecting opening of said breaker only when said closing means is deenergized, a single trip coil operable in-response to predetermined conditions to operate either of said tripping means, and means responsive to the condition of said closing means for preventing the operation of said first-mentioned tripping means by said trip coil only when saidclosing means is deenergized.

13. In combination, a circuit breaker, electromagnetic closing means for said breaker, tripping means for effecting opening of said breaker independently of the energized condition of said closing means, additional tripping means for effecting opening of said breaker only when said closing means is deenergized, a single trip coil operable in response to predetermined conditions to operate either of said tripping means, and means responsive to the magnetic flux of said electromagnetic closing means for automatically selecting which of said tripping means will be operated by said trip coil.

14. In combination, a circuit breaker, electromagnetic closing means for said breaker, tripping means for effecting opening of said breaker independently of the energized condition of said closing means, additional tripping means for effecting opening of said breaker only when said closing means is deenergized, a single trip coil operable in response to predetermined conditions to operate either of said tripping means, and means responsive to the condition of said closing means for causing the tripping of said breaker in response to said predetermined conditions to be effected only by said additional tripping means erable to effect opening of said breaker only when said closing means is deenergized, a single trip coil for operating both of said tripping means, and means responsive to the condition of said closing means for preventing operation of said first-mentioned tripping means by said trip coil when said closing means is deenergized and for v permitting operation of said first-mentioned tripping means when said closing means is deenergized.

16. In combination, a circuit breaker biased to open circuit position, electromagnetic closing means for said breaker, a first latch normally effecting an operative connection between said breaker and said closing means, said latch being releasable to effect opening of said breaker independently of the energized condition of said closing means, a second latch for holding said breaker in closed position while said breaker is operatively connected to said closing means, said second latch being releasable to efiect opening of said breaker only when said closing means is deenergized, tripping means for releasing both of said latches, and means responsive to the condition of said closing means for preventing release of said firstlatch by said tripping means only when said closing means is in deenergized condition.

17. In combination, a circuit breaker biased to open circuit position, closing means'yiorrsaid breaker comprising a closing lever anda solenoid for moving said lever to close said breaker, tripping means comprising a first latch normally and releasably efiecting an operative connection between said breaker and said closing lever, a second latch for releasably holding said closing lever in breaker closed position, a trip coil for releasing both of said latches,- and means including a lost motion connection between said solenoid and said closing lever for preventing release of said first latch only when said solenoid is in deenergized condition.

18. In combination, a circuit breaker, electromagnetic closing means for said breaker, tripping means for effecting opening of said breaker independently of the energized condition of said closing means, additional tripping means for effecting opening of said breaker only when said closing means is deenergized, a trip coil having a plunger operable to operate either of said tripping means, a trip bar rockable about either of its ends interposed between said two tripping means and said plunger having its ends engageable with said tripping means and its mid-portion engageable by said plunger, and means responsive to the condition of said closing means for causing said plunger when operated to rock said trip bar about one of its ends to operate only said additional tripping means when said closing means is in deenergized condition, and for causing said plunger when operated to rock said trip bar about its other end to operate said first-mentioned tripping means when said closing means is in energized condition.

19. In combination, a circuit breaker, electromagnetic closing means for the breaker, trip free tripping means for effecting opening of the breaker independently of the condition of the closing means, additional non-trip-free tripping means for effecting opening of the breaker only when the closing means is deenergized, and means operable to cause tripping of the breaker to be effected by operation of the non-trip-Iree' tripping means after a previous closure of the breaker whenever and only after there has been a lapse of time sufficient for the flux in the closing means to be reduced to substantially zero value.

20. In combination, a circuit breaker, electromagnetic closing means for said breaker, tripfree tripping means for effecting opening of said breaker in response to predetermined conditions independently of the condition of said closing means, additional non-trip-free tripping means for efiecting opening of said breaker in response to predetermined conditions only when said closing means is deenergized, and means responsive to the flux condition of said closing means for automatically selecting which of said tripping means will be operable to trip the breaker.

21. In combination, a circuit breaker, electromagnetic closing means for said breaker, tripfree tripping means for effecting opening of said breaker in response to predetermined conditions independently of the condition of said closing means, additional non-trip-free tripping means for effecting opening of said breaker in response to predetermined conditions only when said c1osing means is deenergized, and means responsive to the flux condition of said closing means for causing tripping of said breaker to be effected only by said non-trip-free tripping means in response to predetermined conditions occurring whenever there is substantially no flux in said closing means which would oppose opening ofthe breaker, and for causing tripping of said breaker in response to predetermined conditions to be effected by said trip-free tripping means whenever there is substantially any flux present in said closing means.

22. In a circuit breaker, electric closing means for said breaker, tripping means for eflecting opening of said breaker irrespective of the condition of said closing means, additional tripping means for efiecting opennig or said breaker only when said closing means is deenergized, means for operating said tripping means, and means responsive to the energized and deenergized conditions of said closing means for automatically selecting which of said tripping means will be operated to trip the breaker at any given time.

23. In combination, a circuit breaker, electric closing means for said breaker, trip free tripping means for e'flecting opening of said breaker in response to predetermined conditions irrespective of the condition of said closing means, additional non-trip-free tripping means for efiecting opening of the breaker in response to predetermined conditions but only when said closing means is deenergized, and means responsive to the energized and deenergized conditions of said closing means for automatically selecting which of said tripping means will be operated to trip