US2403082A - Circuit breaker - Google Patents

Description

July 2, 194%. w, HlLL ET AL 2,403,982

C IRGUIT BREAKER Filed April 4, 1942 5 Sheets-Sheet 1 WITNESSES: KNVENTORS 721d, (7 M Ai /an W H/'// and y Jaggw M {Um/77mg Jul 2, 1946. -A .z.-w.1 amp-LET A}, 03

' CIRCUIT} BREAKER "Filed April 4, 1942 5 Sheets- Sheet s F i g. 6.

w ml 247 3,,

I I 3 26! 257 w WITNESSES: |NVENTO'R5 42 a My Allan w H/ 1/ and James M Q/mm/ng W1 BY I 7 g/ ATTORY Patented July 2, 1946 CIRCUIT BREAKER Allan W. Hill, .Wilkinsburg, and James M.

Cumming, Turtle Creek, Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application April 4, 1942, Serial No. 437,669

20 Claims. 1

This invention relates to circuit breakers, and more particularly to high speed circuit breaker operating mechanisms of the fluid pressure operated type.

An object of the invention is the provision of an improved fluid pressure operated circuit breaker operating mechanism which is mechanically trip free and capable of effecting high speed opening and reclosing of the circuit breaker.

Another object of the invention is to provide a circuit breaker operating mechanism operable by fluidpressure to close the breaker and embodying an improved .pressure exhaust valve construction for the operating cylinder which permite quick retrieving and relatching of the closing means with the breakerfollowing an opening movementrof the breaker- Another object of, the invention is to provide a circuitbreaker operating mechanism operable by fluid pressure whereinthe breaker is releasably connected to the operating mechanism by means of an improved high speed, light load latching mechanism comprising a series of latches arranged to occupy aeminimum amount of space.

Another object of the invention is to provide a circuit breaker having an operating mechanism operable by fluid pressure to close the breaker, wherein the breaker is trip free of the operating mechanism and the mechanism embodies an improved automatic pressure exhaust valve construction which permits high speed retrieving and relatching of the operating mechanism with the breaker.

Another object of the invention is to provide a circuit breaker having an operating mechanism operable by fluid pressure embodying an improved high speed latch mechanism for releasably connecting the operating mechanism to the breaker, an improved high speed exhaust valve construction for quickly exhausting the fluid pressure from the operating mechanism to permit high speed retrieving and relatching of the operating mechanism to the breaker and electroresponsive means for simultaneously operating the trip mechanism and the exhaust valve.

' Another object of the invention is to provide a circuit breaker having an improved operating mechanism operable by fluid pressure to close the breaker, the operating mechanism being connected to the breaker by means of a trip free mechanism and embodying an improved latch means for releasably connecting the breaker to the operating mechanism, an electroresponsive trip device for causing high speed unlatching and a novel high speed exhaust valve construction operable by the tripdevice for quickly exhausting the air pressure to permit quick retrieving and relatching of the operating mechanism to the breaker.

Another object of the invention is to provide an improved automatic reclosing circuit breaker having a fluid motor operating mechanism including a releasable coupling providin a tripfree connection between the motor and the breaker, the mechanism being automatically operable to initiate a reclosing movement of the breaker after the current flow of the circuit is interrupted and at least by the time the breaker reaches full open position.

Another object of th invention is to provide an improved automatic reclosing circuit breaker embodying an operating mechanism operable by fluid pressure having a trip-free connection between the operating mechanism and the breaker and having an improved fluid pressure exhaust means controlled by the breaker tripping means to permit quick reconnection of the operating mechanism to the breaker before the breaker reaches full open position.

Another object of the invention is to provide an improved circuit breaker operating mechanism of the pneumatic type, 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 advantages thereof will be best understood from the following detailed description of a single embodiment thereof when read in conjunction with the accompanying drawings, in which:

Figure 1 is a view partly in side elevation and partly in section of a circuit breaker operating mechanism embodying the principles of the invention,

Fig. 2 is a plan view of the mechanism showing the latching means and the trip-free lever system of the mechanism,

Fig. 3 is a fragmentary horizontal sectional view through the operating cylinder and the dump valve therefor,

Figs. 4 and 5 are side elevational views of a portion of the operating mechanism shown in Fig. 1 illustrating different positions of the levers of the mechanism,

Fig. 6 is a wiring diagram of the circuits for controlling opening and closing of the breaker,

n) the operating mechanism and the circuit breaker being illustrated diagrammatically.

Referring to the drawings, the circuit breaker I shown schematically in Fig. 6, may be of any conventional construction either of the oil break, air break or gas blast type. The circuit breaker, as shown comprises stationary contact means 3 and cooperating movable contact means 5 for controlling a 'main circuit shown diagrammatically by a single line '5. While the circuit breaker is illustrated as comprising a single pole, it is to be understood that the circuit breaker may be of the multi-pole type provided with a set of contact means 3-5 for each pole with the movable contacts mechanically connected for simultaneous operation in the conventional manner. The circuit breaker is biased to open position by means of an accelerating spring 1 shown schematically (Fig. 6), and the breaker is mechanically connected to the operating mechanism by connecting means represented schematically as comprising a lever 8 pivoted at 9 on a fixed support. One end of the lever B is pivotally connected to the breaker lift rod I and the other end is pivotally connected to the breaker operating rod 2| which, in turn, is mechanically connocted to a lever of the mechanism.

Referring now to Fig. 1 of the drawings, the circuit breaker operating mechanism comprises generally a main casting I which forms an operating cylinder l3 having its lower end closed by a closure l secured to the main casting Operating levers indicated generally at H are mounted on the upper portion of the casting II and are retained in closed circuit position by means of a latching mechanism i9 and a latch 4|.

The circuit breaker is normally biased to an open circuit position by the accelerating spring 1 and isconnected by means of the operating rod 2| to an inner lever 23 of the levers indicated generally at H, through the agency of a pivot pin 25 (Fig. 2). The lever 23 carries a latching roller 21 rotatably mounted in one end thereof and adapted to be engaged by the latching mechanism l9 to releasably retain the circuit breaker in closed circuit position.

The lever 23 is pivotally supported at its lefthand end (Figs. 1, 2, 4 and 5) on a pivot pin 29 mounted in an outer lever 3| which is pivotally mounted at its opposite end on the casting II by means of a pair of pivot pins 33 (Fig. 2) supported in projections 35 (Fig. 2) extending up- Wardly from the main casting. Each of the levers 23 and 3| comprise a pair of levers and each pair is suitably secured together for unitary movement.

In the closed circuit position, indicated by the full lines in Fig. l, the outer lever 3| is biased clockwise by means of a pair of retrieving springs 31, one end of each of which springs is securely attached to its corresponding lever 3| by means of a bracket 39 (Fig. 2), while the other ends of said springs abut against the upper face of the casting The lever 3| is normally prevented from clockwise rotation about its pivot 33 by means of a latch 4| pivotally mounted on pivot pin 42 supported on the casting II and biased by a spring 43 into latching engagement with the pin 29 which pivotally connects the levers 23 and 3|.

The latch mechanism H), as previously stated normally restrains the circuit breaker mechanism in closed contact position against the opening force of the accelerating spring 1 (Fig. 6).

The latch mechanism I9 is adapted to be operated in response to predetermined conditions in the circuit controlled by the breaker to release the inner lever 23 (Fig. 1) and thereby permit pening of the circuit breaker.

The latch mechanism 9 includes a main latch member 45 (Figs. 1, 2 and 6), an intermediate latch 41 supported on a pivot pin 48 and which releasably restrains the main latch in latching position, and a trigger latch 49 supported on a pivot pin 50 for releasably restraining the intermediate latch in latching position. The main latch 45 is pivotally supported on a pivot pin 5| and has a latching surface 53 with which a latching projection 55 of the intermediate latch 41 cooperates to restrain the main latch in latching position. The latch pivots 48, 59 and 5| are supported in the projections 35 of the main casting (Figs. 1 and 2). A latch projection 51 of the intermediate latch 41 is adapted to be engaged by the trigger latch 49 to restrain the intermediate latch in latching position. Springs 59, El and 63 respectively bias the latches 45, 4'!v and 49 in latching direction. The spring 59 surrounds a headed rod 65 slidable vertically in a bracket 51 secured to the casting H, the spring 59 being compressed between the head of the rod 65 and a spring seat in the bracket 51. The spring 6| is compressed between a spring seat in the casting II and a projection of the latch 41, and the spring 63 is compressed between the lower portion of the bracket 91 and the trigger latch 49. In order to conserve space the latch members 45, 41 and 49 are mounted in the same lane and are disposed substantially parallel to each other in nested relationship.

The unlatching movement of the main latch 45 is adjustably limited by means of an adjusting screw 59 in the upper end of the bracket 61. A look nut 1| is provided to lock the screw 69 in its adjusted position. By limiting the inward movement of the spring pressed rod 65, the unlatching movement of the main latch 45 is limited so that there is but very slight overtravel in unlatching direction.

The shape of the latch face of the main latch 45 which engages the roller 21 is such that the force exerted thereon by the roller 21 tends to rotate the main latch in unlatching direction and consequently the latch 45 by itself does not serve to hold the breaker mechanism in closed position. Obviously the latch 45 could be constructed so that it alone would hold the circuit breaker in closed position, however, if the latch were so constructed the force required to trip the breaker would necessitate an undesirably large and powerful trip device. Itis to reduce the latch load at the ultimate tripping point and to increase the speed of unlatching that the intermediate latch 41 and the trigger latch 49 are provided.

The angle of the latch surface 53 of the main latch 45 and of the engaging projection 55 of the intermediate latch 41 is such that the latch 41 will not by itself serve to hold the main latch in latching position against the force tending to open the breaker. The trigger latch 49 normally engages the end of the long latching arm 51 of the latch 41, which extends directly beneath the latch 45, to restrain the intermediate latch in its latching position. The load applied to the trigger latch 49 by the intermediate latch 41 is but a very small fraction of the force applied to the latch 45 by the breaker accelerating spring 1 (Fig. 6) through the lever 23 and the latch roller 21. Th trigger latch 49 is provided with r' .3 an arm which extends beneath the arm 51 of the latch 41 and is disposed directly above and in the path of travel of a trip rod 12 of a trip device 13.

The trip device 13 in addition to the trip rod 12 comprises a magnet core 15 of magnetic material attached to the casting II by means of brackets 11, a movable armature 19 and an energizing coil 8|. The magnet core 15 is E-shape and the coil 8| is mounted on the center leg thereof. The trip rod 12 is secured to the center portion of the armature 19 and extends vertically through an opening in the magnet core and througha guide opening in a horizontally extending portion of the casting I. The armature 19 andthe trip rod 12 are biased downwardly by means. of a spring 83 surrounding the upper end of the trip rod 12 and compressed between a collar 85 secured on the rod 12 and the bottom of a counterbore in the casting II.

. When the trip device 12 is energized, the armature 19 is moved upwardly against the core 15 moving the trip rod 12 upwardly therewith. This upward movement of the trip rod causes its upper end to engage the arm 52 and rock the trigger latch 49 clockwise and disengage the arm 51 of the intermediate latch 41. The trip rod 12 is given a slight overthrow which causes the arm 52 to engage an adjustable screw 81 in the arm 51 to accelerate the unlatching movement of the intermediate latch 41. This accelerating force together with the force applied by the angular cam face 53 of the main latch 45 to the projection 55 of the intermediate latch 41 causes the latch to immediately release the main latch 45. The accelerating spring for the circuit breaker now moves the breaker to open circuit position, the upward movement of the rod 2| (Fig. 1) occasioned by the opening movement of the breaker rotating the operating lever 23 counterclockwise about its pivot 29. As the operating lever 23 starts its counterclockwise travel the roller 21 forces the main latch 45 in a counterclockwise direction. As the roller 21 clears the main latch 45 the spring 59 immediately acts to restore the latch to its latching position. in order to prevent the intermediate latch 41 from prematurely returning to its latching position, a holding lever 89 is provided. Ihis lever is pivoted on the pin 48 and is biased in a counterclockwise direction by means of a spring 9| compressed between a spring seat in the casting II and one arm 93 of the lever 89, which arm extends beneath the latch 41 and across the plane of movement thereof. The other arm 95 of the holding lever 89 is provided with a projection 91 which is biased counterclockwise into contact with the end of the lever 23. This restrains the holding lever in inoperative position when the lever 23 is in closed circuit position. When the operating lever 23 is released and rotates toward its open position, the spring 9| acts to rotate the holding lever 89 counterclockwise and, since the spring 9| is stronger than the latch spring 6 I, the arm 93 engages the latch 41 and holds it in unlatched position until the roller end of the lever 23 is returned to latching position. During the retrieving movement of the operating lever 23, the roller 21 engages and rotates the main latch 45 counterclockwise. As the lever 23 arrives at its retrieved latching position, the spring 59 rotates the latch 45 to latching engagement with the roller 21 and at the same time the end of the operating lever 23 engages and rotates the holding lever 89 clockwise to its ineffective position; Thispermits the spring 6| to restore the 6 intermediate latch 41 to its latching Position where it is engaged by the trigger latch 49 and restrained in latching position.

During the initial portion of the movement of the operating lever 23 toward the open position shown in dotted lines in Fig. 1 and-also shown inFig. 5, a projection 99 thereon engages the body portion of the latch 4| and rotates said latch'clockwise to release the pin 29. When the latch 4| releases the pin 29, the retrieving springs 31 expand and rotate the lever 3| clockwise about its fixed pivot 33. This clockwise movement of the lever 3| causes the breaker lever 23 to be rotatedin a clockwise direction about the pivot 25 toward the position shown in Fig. 4 wherein the latching .roller 21 is in its latching position in axial alignment with the pivot pin 33 for the lever 3|.

The operating levers 23 and 3| now both occupy thepositions shown in Fig. 4 and the cir- 'cuit breaker is in-the open circuit position ready to be closed. In order to close the circuit breaker there is provided a piston, |0| reciprocably movable within the operating cylinder |3. The piston 0I is provided with a central hollow cylindrical tube I03 which is slidable in a central openingin the casting II. A connecting rod I05, extending axially through the tube I03, is pivotally connected to the piston IOI by a pin I31 extending through an opening in the rod I05 and through openings in spaced ears I09 (only. one being shown) on a projection II| extending downwardly from the bottom of the piston |0| and slidably fitting within an opening in the bottom closure I5.

The upper end of the connecting rod I05 is threadedly connected to a yoke I I3 having spaced arms ||5 which are pivotally connected to the sides of the outerlever 3| by pivot pins in. In this manner the piston |0| is operatively connected. to the breaker operating rod 2| through the agency of the trip-free operating levers 23 and 3|.. 1

When, as previously described, the latch 4| is operated to release the lever 3| and the springs 31 act to move the lever 3| to the Fig. 4 position, the piston |0| is moved upwardly toward the top of the cylinder I3. border to permit quick and unretarded upward movement of the piston I9I, the cylinder is provided with an improved exhaust valve indicated generally at |I9 (Fig. 3) which is operated under the control of the trip device 13 to cause quick collapse of the fluid pressure in the cylinder I3 above the operating piston. The exhaust valve I I9 comprises a multiple valve member |2| (Fig. 3) slidable in a valve cylinder I23 formed integral with the main casting II. A plurality of piston valves I25 formed integral with the valve member |2| cooperate with a plurality of exhaust ports I21 extending through the wall of the operating cylinder I3 and through the outer wall of the exhaust valve cylinder I23 to the atmosphere. The exhaust ports, however, are normally closed by the piston valves |25. The valve member |2| is biased to. closed position in which the piston valves I25 close their respective exhaust ports I21, by means of a compression spring I29 disposed in one end of the valve cylinder I23. One end of the spring I29 bears against the left-hand end of the valve member |2| and the other end of the spring bears against a plate |3| which forms the closure for the left-hand end of the valve cylinder I23. The plate |3I is provided with an opening I33 to prevent trapping of the fluid between the plate. |3|

and the left-hand piston valve I25 upon operation of the valve member I2I.

The purpose of the multiple piston valve and multiple exhaust port construction is to provide a substantiall instantaneous exhaustion of the fluid pressure in the operating cylinder I3 whenever the trip. device 13 is operated and to thus prevent fluid pressure in the cylinder above the operating piston from retarding upward movementoi' the piston MI and of the operating lever 31. The construction thus permits high speed retrieving operation of the levers 3I and 23-, and the strength of the retrieving springs is preferably such that the breaker lever23 isretrieved to its latching position before thebreaker reaches full open position or at least by the time the breaker reaches full open position. This permits a substantially instantaneous reclosure of the breaker. It can be seen that these exhaust valves moving a given distance will uncover three times the exhaust port area as would a single valve traveling the same distance, and they thus dump the fluid pressure in a much shorter time.

A pilot valve, indicated generally at I34 (Figs. L and 3) is operated by the trip device 13 to start the exhaust valve member I2I in opening direction, the valve member I 2| being moved to full open position by the fluid pressure from the main operating cylinder I3.

The pilot valve comprises a cylindrical cupshaped valve member I35 biased against a flanged collar I31 secured to the lower end of the trip rod 12, by means of a spring I39. One end of the spring I39 bears against the valve member I35 and the other end of the spring bears against the bottom of a nut I4I on the trip rod 12. The pilot valve I35 is slidable in a pilot valve housing I43 and the flange of the collar I31 is seated against a shoulder formed in the opening in the housing I43 which receives the valve I35. The pilot valve is disposed in an air passage I45 in the housing I 43 and this passage on one side of the valve I35 communicates with the main operating cylinder I3 by means of a port I41 formed in the casting II. From the other side of the pilot valve I35, the air passage I45 communicates with the exhaust cylinder I23 through the agency of'a tube I49 (Fig. 3) having one end connected to the valve housing I43 and the other end connected to an end closure member II in the valve cylinder I23.

When the trip device 13 is energized and the trip rod moves upwardly to operate the latch mechanism I9, the pilot valve I35 is raised there'- with by means of the collar I31; opening the passage I 45 and admitting air pressure through the tube I49 (Fig. 3) to the end of the cylinder I23. At the same time, the retrieving springs 31 (Fig. 1) acting on the lever 3I move the piston I9I upwardly and the rush of compressed air through the passages I41 and I45 forces the pilot valve I35 upwardly compressing the spring I39 and opening the valve a greater extent. The compressed air admitted through the passages I41, I45 and I49 starts the exhaust valve toward the left in opening direction. As soon as the exhaust valves I25 are open a small distance the air pressure passing over the right-hand sides of the exhaust valves I25 forces the exhaust valves toward the left to fully open position and maintains them in this position until the rising piston I9I closes the exhaust ports I21, whereupon the spring I29 reacts to close the exhaust valve. The air pressure on the bottom of the pilot valve I35 maintains this valve in open position against the force of the spring I39 until the air pressure falls to a. point where the spring I39 acts to close the pilot valve.

The exhaust ports I21 are located in the side wall of the operating cylinder I3 at a point intermediate the end positions of the operating piston I9I so that these ports will be closed by the piston I9I after the breaker has opened a distance sufllcient to interrupt the circuit and before the operating piston reaches the position in its upward travel at which compressed air is admitted for a quick automatic reclosing operation. This arrangement prevents dumping of the quick reclosing air pressure and also allows a time interval during which the main exhaust valve member I2I is moved to close the exhaust ports I21. The quick dumping of the air pressure in the maIn operating cylinder permits a fast retrieving movement of the piston I9I and of the lever 3 I. It will thus be seen that the rapid upward movement of the piston I9I permits relatching of the circuit breaker mechanism with the operating piston before the breaker is fully open or at least by the time the breaker reaches full open position and thus provides for a quick reclosure.

A pair of auxiliary switch devices I63 and I55 (Fig. l) is mounted on a bracket I61 secured to the main casting II, Each of the auxiliary switch devices is of conventional design and comprises a multi-pole auxiliary switch wherein the individual switch members are adjustable relative to their operating shafts I69 and HI, respectively. By this means the auxiliary switches may be adjusted to operate at predetermined points in the operation of the main circuit breaker. The operating shafts I99 and HI have secured, respectively, thereto, crank arms I13 and I15 which are pivotally connected to a yoke member I11 by means of links I19 and I8I. The yoke member I11 is; :provided with a pair of ears I93, and one end of a link I95'is connected thereto by means of a pivot pin I81. The link I is formed substantially as shown. in Fig. 2 and has its other end connected to the pin 25 which connects the circuit breaker operating rod 2| to the operating lever 23. Thus the auxiliary switch devices I53 and I65 are operated in accordance with the movement of the circuit breaker I.

Referring to the circuit diagram (Fig. 6) which diagrammatically illustrates the circuits for controlling an inlet valve electromagnet I59 and the trip device 13, a pair of supply conductors I89 and I9I are connected to a source of electric energy (not shown). The winding I93 of the electromagnet I59 which controls the admission of compressed air to the upper end, of the operating cylinder for closing the circuit breaker is connected in an energizing circuit I95 extending from the supply conductor I89, through the winding I93, through contacts I91 of a release relay I 99, through contacts 29I of an operating relay 293 tov the supply conductor I9I. The energizing winding of the operating relay 293 is connected in an energizing circuit extending from the supply conductor I9I, through a conductor 295, back contacts 291 of the release relay I99, winding of the operating relay 293, a conductor 299 and through a manual control switch 2 I I to the supply conductor I99. The windin of the release relay I99 is connected in an energizing circuit extending from the supply conductor I9 I through an auxiliary switch 2I3 which is adapted to be closed when the circuit breaker reaches closed position, a conductor 2I5, winding of the release relay I99, conductor 2I1, contacts 2I9 oi the operatingrelay 293 andthrough a conductor 22| to the supply conductor I89.

A stick circuit is provided for maintaining the operating relay 293 energized after a momentary operation of the manual closing switch 2| I. This circuit extends from the supply conductor I9I, through the conductor 295 and contacts 291 of the release relay I99, winding of the relay 293, through a conductor 223, conductor 2I1, contacts 2| 9 of the relay 203 and the conductor 22I to the supply conductor I89. A holding circuit is provided for maintaining the release relay I99 energized until the manual closing switch 2II is opened. This holding circuit extends from the supply conductor I9I, a conductor 225, contacts 221 of the relay I99, the winding of the relay I99, conductor 223, conductor 299 and the manual closing switch 2| I to the supply conductor I89.

' The winding '81 of the trip device 13 is connected in an energizing circuit extending from the supply conductor |9I through a conductor 229, through an auxiliary switch 23I which is closed when the circuit breaker is closed, a conductor 233, winding 8| of the trip device 13, a conductor 235 and contacts 231 of a fault respon sive relay 239, through a conductor '24I to the supply conductor I89. The fault responsive relay 239 is adapted to be operated to close its contacts upon the occurrence of an overload of predetermined magnitude, such, for example, as a short circuit in the main circuit 6 controlled by the circuit breaker I. For this purpose, the winding-of the protective r fault relay'239 is energized by a current transformer 243 associated with the circuit 6. i

When a predetermined overload condition or a short circuit occurs in the main circuit 6, the fault responsive relay 239 is energized sufficiently to close its contacts 231, thus causing energization of the trip device'13. When the trip device is energizedjit causes operation of the latching'mechahism I9 (Fig. 1) to release the operating lever- 23,- whereupon the circuit breaker is quickly moved to open position in the previously described manner.

' The-circuit breaker may also be tripped open manually by means of a manually operable switch 245. (Fig. 6) connected in series with a conductor 241 which is'arranged to shunt the contacts231 of the fault relay 239.

The circuit breaker is adapted to be automatically reclosed immediately following interruption of the circuit, through the agency of a reclosing relay 248; The contacts 249 of the reclosing relay are connected by means of a 1 conductor 25I in shunt relation with the contacts of the manual closing switch 2| I. In order to prevent quick automatic reclosing operation of the breaker when such operation is not desired,

a manually operable switch 253 is connected in the conductor 25I'. The winding of the reclosing relay 248' is connected in a circuit extending from the supply conductor I9I through a conductor 255,'the winding of'relay 248, a conductor 251, through an adjustable auxiliary switch 259 which is adjusted to close during the initial opening movement of the circuit breaker, through contacts 28I of the fault relay 239 and conductor 24I to the source conductor I89.

- Assuming that the circuit breaker is in the closed position as shown in Figs. 1 and 6, the operation of the mechanism is as follows: When a predetermined overload or short circuit occurs in the main circuit 6, the fault relay 2391s immediately' energized and closes its contacts 231 therebyeffecting energization' of the trip device 13. As previously described energization of the trip device causes operation of the latch mechanism I9 (Fig. 1) to release the breaker operating lever 23. The circuit breaker is immediately moved toward its open position by the accelerating spring 1 (Fig. 6). As the operating lever 23 rotates counterclockwise about the pivot 29, the projection 99 thereon operates the latch 4| to release the lever 3|. The operation of the trip device 13 also operates the pilot valve I34 causing the main exhaust valve to be opened and quickly exhaust any pressure that may be in the operating cylinder. When the latch 4| is operated, releasing the lever 3|, the retrieving springs 31 (Fig.1) act to'quickly rotate the lever 3| clockwise about the fixed pivots 33. Since the three exhaust ports I21 are open the piston IIJI moves upwardly at a rate of speed higher than the speed of opening movement of the breaker operating rod 2|. Consequently the clockwise rotation of the operating lever 3| carries the pivot pin 29 therewith and causes rotation '01 the lever 23 in a clockwise direction about the pivot 25. This results in reengaging roller 21 with the latch before or at least by the time the circuit breaker reaches full open position.

Assuming that the switch 253 is closed, a quick reclosure of the breaker will occur as soon as the operating lever '23 is relatched by the latch member 45 which occurs after the circuit is interrupted but before or by the time the breaker reaches full open position. Quick automaticreclosing of the circuit breaker is eifected by the reclosing relay 248 which is energized by the closing of the contacts 26I (Fig. 6) by the fault relay and the closing of the auxiliary switch 259. The contacts 29I are closed imultaneously with the contacts 231 bythe fault relay upon the occurrence of an overload or short circuit and immediately prepare the energizing circuit for the reclosing relay 248. The auxiliary switch 259 closes during the initial opening movement of the circuit breaker and completes the circuit for the reclosing relay 248. The relay 248 thereupon closes its contacts 249 completing the previously described circuit for the operating relay203 which instantly closes'its contacts 2I9 and 20L Closing of the contacts 29| completes the circuit for energizing the electromagnet I59 through the back contacts I91 of the release relay I99. H Energization of the electromagnet I59 opens the pilot valve I51 which, in turn, causes opening of the main inlet valve I53. The inlet valve is connected by pipe I55 to a source of compressed air IBI and upon opening of the inlet valve compressed air is admitted to the upper end of the operating cylinder I3 quickly moving theoperating piston III'I downwardly. Since the operating lever '23 is now reengaged with the latch, the downward movement of the piston IflI is communicated by means of the operating levers 23--3| to close the circuit breaker. These operations occur substantially instantaneously so that the reclosing movement of the operating pis, ton is initiated immediately after the circuit has been interrupter and before or at least by the time the breaker reaches full open position.

Closing of the contacts 2 I9 of the operating relay 203 prepares the previously described circuit for the release relay I99. As soon as the circuit breaker reaches closed position, the auxiliary switch 2I3 completes the circuit for the release relay I99 which immediately operates to open its back contacts I91 and 201 and close itsfront contacts 221. The opening of the contacts I91 effects the deenergization of the electromagnet I59 which controls the inlet valve and thereby closes the inlet valve and interrupts the supply of compressed air to the operating cylinder I3. Opening of the contacts 201 causes deenergization of the operating relay 203. Since the contacts 249 of the reclosing relay 248 open before the breaker reaches closed position, the closing of the contacts 221 have no effect during quick automatic reclosing operations.

If the condition which caused the overload or short circuit has been removed by the time the circuit breaker completes the circuit upon a quick automatic reclosing operation, the breaker remains closed and the control circuits return to normal condition as shown in Fig. 6. However, the fault condition is still present at the time the main circuit Ii is completed by the contacts 3-5 of the circuit breaker during a quick reclosing operation, the fault relay 239 is again energized and causes energization of the trip device. 13. Consequently the trip device is again operated and operates the latch mechanism I9 and thereby disconnects the operating lever 23 from the operating piston IIH. The accelerating spring 'I immediately moves the breaker toward open position. At the same time, the trip device IS-operates the pilot valve I34, thereby causing the closing air pressure in the operating cylinder to open the main exhaust valves I25 and quickly cause collapse of the air pressure in the operating cylinder, even though the inlet valve I53 may still be open at this time.

A lockout device 263 of an suitable design may be provided in the circuit of the reclosing relay 3 to prevent more than one quick automatic reclosing operation of the circuit breaker, or to open the quick reclosing circuit and transfer the control of the reclosing relayto a time delay reclosing device in a manner well known in the art.

I! the lockout device 233 is constructed to provide for only one quick automatic reclosure of the circuit breaker, the breaker goes to its full open position and remains open after one quick reclosure. In this condition of the breaker the operating rod 2| and the operating levers 23 and 3I will assume the position shown in Fig. 4 with the operating piston IIII (Fig. 1) in its upper position in readiness for a normal closing operation.

In order to effect a normal closing operation of the circuit breaker from the full open position, the manual control switch 2II is closed. This completes a circuit for the operating relay 203 which. when energized, closes its contacts 2III and 2I9. Closing of the contacts ZIlI completes the circuit for energizing the inlet valve controlling electromagnet I93 which causes compressed. air to be admitted to the operating cylinder to close the breaker. Closing of the contacts 2I9 prepares the circuit for energizing the release relay I99, this circuit being completed by the auxiliary switch 2I3 when the circuit breaker reaches the fully closed position. The manual closing switch 2 need be closed for only an instant since closure of the contacts 2 I9 completes the previously described holding circuit for maintaining the operating relay 203 energized until the release relay I99 operates. When the release relay ISO is energized, it opens the contacts I9! and 201 thereby deenergizing the inlet valve control magnet I59 and also deenergizes the operating relay 203 and prevents energization of the operating relay as long as the contacts 201 remain open. The operation of the release relay I99 also closes the contacts 221 to complete the holding circuit for maintaining the release relay I99 energized as long as the manual switch 2I I is held closed, thus preventing the circuit breaker from pumping should the breaker fail to remain closed and the manual switch 2 I I is held in closed position. If the circuit breaker should be closed against an overload or short circuit during a. normal closing operation, the trip device I3 will be operated to release the latch 45 and exhaust the air in the cylinder so that the breaker will be immediately opened in the previously described manner.

The circuit breaker may be manually tripped open by closing the manual trip switch 245 which causes energization of the trip device 13.

The circuit breaker is trip free of the operating mechanism in all positions, that is, if a fault occurs during the closing movement, the trip device 13 will be immediately energized to disconnect the breaker mechanism from the operat-' ing mechanism and permit the accelerating spring 1 to immediately operate the breaker to open position irrespective of the closing air pressure in the operating cylinder I3.

The circuit breaker may be closed manually by any suitable manually operable closing device which may be attached to the free end of the outer operating lines 3 I.

Having described one embodiment of the invention in accordance with the patent statutes, it is to be understood that various changes and modifications may be made in the particular embodiment disclosed without departing from some of the essential features of the invention. It is desired, therefore, that the language of the appended claims be given as reasonably broad interpretation as the prior art permits.

We claim as our invention:

1. A high speed operating mechanism for a circuit breaker comprising a motor operable by gas under pressure to close the breaker, a source of gas under pressure, an inlet valve for admittin gas under pressure to said motor to close the breaker, latch means for releasably connecting the motor to the circuit breaker, means for quickly reducing the gas pressure in the motor, means for automatically reconnecting the motor to the circuit breaker, and electroresponsive means for operating the latch means and simultaneously initiating operation of the pressure reducing means.

2. An operating mechanism for a circuit breaker comprising a fluid motor, a source of gas under pressure, an inlet valve for admitting gas under pressure to said motor to operate the breaker to closed position, a latch mechanism operable to disconnect the breaker from said motor to permit operation of the breaker to open position, compressed gas operated means to quickly reduce the gas pressure in the motor to permit quick reversal of the motor, means fOr automatically causing relatching of the motor to the breaker, and electroresponsive mean for simultaneously operating the latch mechanism and for admitting compressed gas to operate the pressure reducing means.

3. An operating mechanism for a circuit breaker comprising a fluid motor, a source of gas under pressure, means for admitting compressed gas to said motor to operate the breaker to closed position, a trip free mechanism operatively relating said motor to the breaker and operable to permit operation of the breaker to open position, means comprising a multiple valve operable b compressed gas to cause quick collapse of pressure on the working side of said motor to permit high speed resetting of said trip free mechanism, a pilot valve operable to admit compressed gas to operate said multiple valve, and trip means operable in response to predetermined circuit conditions to trip said trip free mechanism and simultaneously operate the pilot valve.

4. An operating mechanism for a circuit break er comprising a fluid motor, means for admitting fluid under pressure to said motor to operate the breaker to closed position, latch mechanism for connecting said motor to the breaker and operable to disconnect the breaker from the motor for permitting opening of the breaker, means comprising a plurality of piston type valves operable to open a plurality of passages and thereby cause quick collapse of the fluid pressureon the working side of said motor, spring means for causing reconnection of the motor to the breaker, and electroresponsive means operable in response to predetermined circuit conditions to operate the latch mechanism and to initiate operation of said valves.

5. A fluid pressure operating mechanism for a circuit breaker comprising a cylinder, a piston reciprocably movable in said cylinder and'operable by fluid pressure to close the breaker, a trip free mechanism operatively relatingsaid piston to the breaker, a trip device operable in response to predetermined circuit conditions to trip said trip free mechanism to thereby trip said breaker free of said piston, spring means'for moving the piston to cause automatic resetting of the trip free mechanism,means comprising a plurality of piston type exhaust valves operable under the control of the trip device to cause quick collapse of the fluid pressure in the cylinder, and an inlet valve operable to admit fluid under pressure to the cylinder for actuating the piston to close the breaker.

6. An operating mechanism for a circuit breaker comprising a cylinder, a piston in the cylinder, a latch mechanism for releasably connecting said piston to the breaker, an inlet valve operable to admit air pressure to said cylinder for actuating the piston to close the breaker, a trip device operable in response to predetermined circuit condition to operate the latch mechanism and cause opening of the breaker, spring means for actuating the piston to cause relatching thereof to the breaker, means comprising an exhaust valve operable under control of the trip device for causing quick collapse of pressure in the cylinder and thereby permit high speed relatching movement of the piston, said trip device being operable to cause opening of the breaker irrespective of the movement of th piston.

7. An operating mechanism for a circuit breaker comprising a fluid motor operable by fluid under pressure to close the breaker, latching means for releasably connecting said motor to the breaker, said latching means comprising a main latch biased to latching position for en.- gaging a part movable with the breaker and restraining said part in a predetermined position, an intermediate latch for engaging said main latch and restraining said main latch inv latchil'lg position, said intermediate latch having apart disposed generally parallel to and in nested relation with a portion of the main latch, and a light load trigger latch for engaging andrestraining the intermediate latch in latchin position, said light load latch having a part dis,-

14 posed in nested relation with the intermediate latch, and a trip device operable in response to predetermined circuit conditions for operating the trigger latch to cause the main latch to release the part movable with the breaker and thereby cause opening of the breaker.

8. The invention according to claim '7, characterized by the provision of means for adjustably limiting the unlatching movement of the main latch to provide for high speed relatching.

9. An operating mechanism for a circuit breaker comprising a fluid motor operable by fluid under pressure to close the breaker, means comprising an inlet valve for admitting fluid to said motor, latch means for releasably connecting the motor to the breaker, electroresponsive means for operating said latch means to cause opening of the breaker. means automatically operable following disconnection of the motor from the breakers to move the motor to cause reconnection thereof with the breaker, and a pneumatically operated exhaust valve for causing quick collapse of the fl-uid pressure in the motor to permit high speed relatching movement of the motor, said ex haust valve comprising a plurality of piston type valves connected for unitary movement to simultaneously open a plurality of exhaust ports.

10. A circuit breaker comprising relatively movable contacts, a fluid motor operable by fluid under pressure to close said contacts, latch means releasably connecting said motor to the breaker, exhaust means for quickly exhausting the fluid pressure from the motor, a trip device operable in response to predetermined conditions in the circuit controlled by the breaker for operating the latch to cause opening of the contacts, said trip means also operating the exhaust means, reset means operable to cause relatching oi the motor to the breaker at least by the time the breaker reaches full open position, and means operable after the contacts have separated and before the breaker reaches full open position to admit fluid under pressure to the motor to initiate a closin movement of the contacts.

11. A circuit breaker comprising relatively movable contacts for opening and closing an electrical circuit, closing means comprising a motor operable by fluid under pressure to move the contacts to closed position, a releasable connection between the motor and the movable contacts, a trip device operable in response to predetermined circuit conditions to disconnect the breaker from the motor to cause opening movement of the contacts, exhaust means operable by said trip device to' quickly exhaust the fluid pressure from the motor, spring means operable to cause reconnection of the motor to the breaker before the contacts have reached full open position, and means ,operable to admit fluid under pressure to the motor to initiate a closing movement of the breaker before the contacts reach full open position, said trip device being operable to initiate an opening movement of the breaker irrespective of the condition of the closing means.

12, A circuit breaker comprising relatively movable contacts, operating means for said contacts comprising an operating cylinder, a piston movable in said cylinder and releasably coupled to the breaker, a source of compressed air for operating said piston, means including an electroresponsive device operable in response to predetermined abnormal circuit conditions to uncouple the breaker from the piston and cause opening of the breaker; pressure exhaust means associated with said cylinderincluding a normally closed exhaust valve operable by said electroresponsive device to cause collapse of the pressure in the cylinder, spring means automatically operable to cause recoupling of the piston to the breaker before said breaker reaches full open position, and means including an inlet valve operable to admit compressed air to the cylinder to close the breaker, said electroresponsive device being operable to uncouple the breaker from the piston irrespective of the air pressure in the cylinder.

13. A circuit breaker comprising relatively movable contacts biased to an open position, operating means therefor including an operating cylinder, a piston movable in said cylinder and releasably coupled to said breaker, a source of compressed air for operating the piston to close the breaker, an electroresponsive trip device operable in response to predetermined abnormal conditions in the circuit controlled by the breaker to cause uncoupling of the breaker from the piston and thereby cause opening movement of the breaker independently of the movement of the piston, means including an exhaust valve associated with said cylinder and operable under the control of the electroresponsive means to cause quick collapse of the air pressure in the cylinder, means comprising a spring operable to cause recoupling of the piston with the breaker, and means including an inlet valve operable to admit compressed air to the cylinder to close the breaker.

14. A circuit breaker comprising relatively movable contacts biased to an open position, operating means therefor including a fluid motor releasably coupled to said breaker, a trip device operable to cause uncoupling of the breaker from the motor and opening of the breaker, means for causing automatic recoupling of the motor to the breaker, means operable when said breaker moves to open position to cause compressed fluid to be admitted to the motor and initiate a reclosing movement of the breaker after interruption of the circuit and by the time the breaker reaches full open position, said trip device being operable in response to predetermined abnormal condition in the circuit of the breaker to cause uncoupling of the breaker from the motor and thereby cause opening of the breaker irrespective of the condition of the motor.

15. An operating mechanism for a circuit breaker comprising a cylinder, a piston movable in said cylinder and operable by fluid pressure to close the breaker, means comprising an actuating lever pivoted on a fixed pivot and an operating lever pivoted on said actuating lever for releasably connecting the piston to the breaker, means for restraining said levers in connected relation, a trip device including an electromagnet operable in response to predetermined abnormal conditions in the circuit controlled by the breaker for operating the restraining means and thereby permit opening movement of the operating lever and the breaker irrespective of the position of the piston, an exhaust valve operable by the trip device to cause quick collapse of the fluid pressure from the cylinder, and spring means to automatically move the actuating lever to reestablish the connection of the piston to the breaker at least by the time the breaker reaches full open position.

16. An operating mechanism for a circuit breaker comprising a cylinder, a piston movable in said cylinder and operable by fluid pressure to close the breaker, a pivoted actuating lever pivotally supported on a fixed pivot and operatively connected to said piston, an operating lever pivotally mounted on said actuating lever and operatively connected to the breaker, a plurality of latch member for releasably restraining said levers in a normal position, a trip device including an electromagnet operable to release the operating lever and cause opening of the breaker, said operating lever effecting unlatching of the actuating lever as it moves to an open position, an exhaust valve operable under the control of the trip device to effect quick collapse of pressure in the cylinder, spring mean automatically operable to rotate the actuating lever about th fixed pivot to cause relatching of the operating lever at least by the time the breaker reaches open position, and an inlet valve operable when the breaker moves to open position to admit compressed fluid to the cylinder and initiate a closing movement of the piston after interruption of the circuit and by the time the breaker reaches full open position.

17. An operating mechanism for a circuit breaker comprising a fluid motor operable by fluid pressure to close the breaker, means for admitting fluid pressure to said motor, means including a retrieving lever and a trip free lever, means releasably engaging the trip free lever to retain it in a predetermined position, an electromagnet operable in response to predetermined circuit conditions to trip the engaging means to release the trip free lever and permit movement of the breaker to open position, an exhaust valve operable to cause quick collapse of the fluid pressure in the motor, and spring means for automatically moving the retrieving lever to cause the engaging means to reengage the trip free lever at least by the time the breaker reaches full open position.

18. In a. circuit breaker, the combination of an operating mechanism comprising a fluid motor operable by fluid pressure to close the breaker, mean for admitting fluid pressure to said motor, an actuating lever pivotally supported on a fixed pivot and operatively connected to the motor, an operating lever pivotally mounted on said actuating lever and operatively connected to the breaker, a latch member for releasably restraining the free end of the actuating lever in a normal position, a second latch member for releasably restraining the operating lever in a closed position, a trip device operable in response to predetermined circuit condition to operate the second named latch to release the operatin lever and permit move ment of the breaker to open position, the first named latch member being operated by the operating lever to release the actuating lever, an exhaust valve operable by the trip device to cause quick collapse of the fluid pressure in the motor, and spring means for automatically moving the actuating lever to cause relatching of the operating lever.

19. An operating mechanism for a circuit breaker comprising a motor operable by compressed gas, a source of gas under pressure, an inlet valve for admitting compressed gas to said motor to close the breaker, latch means for releasably connecting the motor to the circuit breaker, a compressed gas operated valve for quickly reducing the Working pressure in the motor, a pilot valve for admitting compressed gas to operate said pressure reducing valve, means for automatically reconnecting the motor to the circuit breaker, and electroresponsive means for operating the latch means to disconnect the breaker from the motor and for operating said pilot valve.

20. A circuit breaker comprising relatively movable contacts biased to an open position, op-

crating means therefor including an operating cylinder, a piston movable in said cylinder, a trip free mechanism operatively relating said piston to the breaker, a source of gas under pressure, an electroresponsive trip device operable in response to predetermined abnormal conditions in the circuit controlled by the breaker to trip said trip free mechanism to trip said breaker free of the piston and thereby cause opening movement of the breaker independently of the movement 10

Images