US2384801A

US2384801A - Circuit breaker

Info

Publication number: US2384801A
Application number: US445881A
Authority: US
Inventors: James M Cumming; Henry L Peek
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1942-06-05
Filing date: 1942-06-05
Publication date: 1945-09-18
Anticipated expiration: 1962-09-18

Description

'Sept. 18, 1945- J. M. CUMMING ETYAL CIRCUIT BREAKER Filed June 5. 1942 SSheets-Sheec 1 INVENTORS .ZbmesM ummin and Hen a a/ WITNESSES: .5. 4 .l

ry L Pee/t.

ATTQRN;

Sept. 18, 1945.

WITNESSES:

J. M. CUMMING ET AL C IRCUI T BREAKER Filed June 5, 1942 3 Sheets-Sheet 2 Fig. 2,

. INVENTOR5 James/l Cum/ruby and Hear 4. -re'K.

Sept. 18, 1945. J. M. CUMMING ET AL 0 I CIRCUIT BREAKER Filed June 5, 1942 3 Sheds-Sheet 3 22/ I as WITNESSES: INVENTORS v fame. M Cummingand Henry Z. eeK.

Patented Sept. 18, 1945 CIRCUIT BREAKER James M. Cumming, Turtle Creek, Pa., and Henry Peek, Camp Gordon, Ga., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application June 5, 1942, Serial No. 445,881

21 Claims.

The invention relates to circuit breakers and,

more particularly, to. circuit breaker operating mechanisms of the fluid pressure type which are operable to produce closing or quick automatic reclosing of the circuit breaker.

This invention is a further development and on closing operations started from the full open position to prevent slamming of the breaker,

Another object of the invention is to provide a circuit breaker embodying a compressed gas operating mechanism operable to efiect closing of the breaker from the full open position and quick automatic closing of the breaker, the mechanism being provided with an improved means for causing a greater force to be applied on quick automatic reclosing operations than on normal closing operations.

Another object of the invention is to provide a circuit breaker embodying a compressed airoperating mechanism having means for exhausting the air pressure on one side of the piston on opening operations and means operated by the piston during the opening stroke to reduce the rate at which the air is exhausted.

Another object of the invention is to provide a circuit breaker embodyin a compressed gas operating mechanism operable to effect normal closing of the breaker and also operable to effect quick automatic reclosing operation of the breaker, the mechanism having an improved ar-' dependently of the reducing means to regulate the operating force. I

Another object of the invention is to p ovide a circuit breaker embodying an operating mechanism which is pneumatically operated to produce normal closing of the breaker, and also operated to produce quick automatic reclosing operations, the mechanism being provided with an automatically operated valve for reducing the air pressure applied to the operating piston on normal closing operations and to cause greater driv ing force to be applied on quick 'reclosing operations, and having means independent of the valve for regulating the rate of flow of compressed air.

Another object of the invention is to provide a circuit breaker embodying an operating mechanism operated by compressed air to produce normal closing and quick reclosing of the breaker with rapid reversal of switching movement of the breaker, the mechanism having an automatically operable valve for reducing the air pressure applied to the piston on normal closing operations and to cause full air pressure to be applied to the piston on quick reclosing operations, and having a bypass around the throttle valve for admitting compressed air to the piston onnormal closing operations when the throttle valve is closed.

Another object of the invention is to provide a circuit breaker operating mechanism operated by compressed air to produce normal closing and also to produce quick automatic reclosing of the breaker with rapid reversal of the switching movement of the breaker, the mechanism having a valve operable to closed and open positions by the mechanism to reduce the air pressure applied to the piston on normal closing operations and to cause iull air pressure to be applied to the piston on quick reclosing operations, and havin a bypass channel for admitting compressed air to the piston independently of the throttle valve, the bypass channel having adjusting means to regulate the rate of flow of compressed air applied to the piston on normal closing operations.

Another object of the invention is to provide a circuit breaker operating mechanism wherein the operation of a pressure exhaust valve is initiated by an electromagnet and the valve is thereafter moved to full open position by fluid pressure.

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 f ollowing detailed description of one embodiment thereof when read in conjunction with the accompanying drawings; in which:

Figure l is an elevational view, partly in section, of a compressed air mechanism for operating a circuit breaker embodying the principles of the invention, the mechanism being shown in the breaker closed position;

Fig. 2 is a vertical sectional view taken on line IIII of Fig. 1;

Fig. 3 is a. fragmentary horizontal sectional view taken substantially on line III-HI of Fig. 2 showing the inlet valve, the throttle valve and the bypass channel, and partly broken away to show the throttle valve latch; and

Fig. 4 is a fragmentary Vertical sectional view taken on line IV-IV of Fig. 2 showing the throttle valve and throttle valve latch.

Referring to Figs. 1 and 2 of the drawings the circuit breaker operating mechanism comprises, generally, a main casting II provided with mounting members I3 whereby the main casting may be secured to a suitable support, for instance, the side of a. circuit breaker housing, an operating cylinder I5 in the casting, a piston II movable in the cylinder, a trip device indicated generally at I9 (Fig. 1), an inlet valve 2| (Fig. 2) for admitting compressed air to th cylinder to effect closing movement of the piston IT, a valve 23 for controlling the air intake, an exhaust valve mechanism 25, and a latch mechanism indicated generally at 21 (Fig. l).

The lower end of the cylinder I5 is closed by means of a closure member 29 secured to the main casting II by means of bolts 3|, the upper end of the cylinder I5 being closed by a portion 33 of the casting. The piston I1 includes an upwardly extending hollow tube 35 which slidably fits within an opening in the portion 33 of the casting II. The lower end of the tube I5 fits over an inwardly extending annular flange 31 in the closed position of the piston. Durin downward or closing movement of the piston the air trapped by the piston between the flange 31, the cylinder wall I5 and the closure 29 acts as a cushion for the piston and the operating mechanism. The piston I1 is provided with one or more piston rings 39 (onl one being shown).

The tube 35 is connected at its upper end by means of a. pivot pin 4! to a link 43, which, in turn, is connected at its upper end, by means of a pivot pin 45, to a coupling 41 secured on the lower end of a breaker operating rod 49. The operating rod 49 is connected by suitable linkage to the circuit breaker mechanism shown schematically at 50 (Fig. 2) which may be an air breaker or an oil breaker of any conventional type. The breaker mechanism is biased to open position and actuated to open the breaker contacts by means of an accelerating spr ng 52.

The pivot pin 45 (Fig. 2) which connects the link 43 to the coupling 41, extends beyond the sides of the coupling and is connected by means of suitable bearing members 5i to an operatin lever 53 comprising a pair of spaced parallel levers. As shown in Fig. 1 the levers 53 are pivotally supported, at their right hand ends, by means of a pivot pin 55, on the upper end of a link 5! whose lower end is pivoted on a pivot pin 59 mounted in a pair of ears GI projecting outwardly and upwardly from the main casting II.

The left hand ends (Fig. 1) of the levers 53 are rigidly connected by means of a rod 3 an are spaced apart by a roller 55 rotatably mounted on the rod 63 between the levers. The latch mechanism 2'! normally cooperates with the roller 55 to releasably restrain the breaker mechanism in closed position.

The latch mechanism 21 includes a main latch 51 pivotally supported on a pivot pin 59 mounted in projections II extending upwardly from the main casting II. The main latch 81 is biased to latching position by means of a spring I3 coiled around a rod I5 and compressed between a projection T! of the casting II and a washer "I9 supported on the lower end of the rod "I5 by a nut BI. The rod I5 extends upwardly through a guide opening in the projection I1 and is pivotally connected at its upper end by means of a pivot pin 83 to the main latch 61.

The configuration of the latching surface of the main latch 61 is such that it will not, by itself, retain the operating mechanism in closed position. An auxiliary latch 85 is provided to maintain the main latch 61 in latching position. The auxiliary latch 85 is pivoted on a pivot pin 81 supported in the projection II of the casting II and a latching projection 89 thereof is biased by means of a spring 9I into latching engagement with a tail 93 of the main latch.

The auxiliary latch 85 is provided with a horizontally extending portion 95 the free end of which is disposed directly above and in alignment with a vertically d sposed trip rod 91 forming a part of the trip device IS. The trip device includes, in addition to the trip rod 91, a trip magnet comprising an E-shaped magnet core 99 supported by means of a pair of brackets IIJI on the under side of a projection I03 of the casting II, the brackets IOI being secured to the projection I03 by means of bolts I05. An energizing coil III'I surrounding the center leg of the core 99 and suitably supported in the magnet frame, is provided to energize the trip magnet. A movable armature I09 secured on the lower end of the trip rod 91 cooperates with the magnet core 99 when the coil I 01 is energized to thrust the trip rod upwardly to effect tripping of the breaker. The downward movement of he armature I09 and of the trip rod 9! is limited by engagement with a manual trip rod II I vertically slidably mounted in a guide sleeve I I3 threadedly secured on a horizontal projection I I5 of the cast ng I I. The vertical movement of the manual trip rod II I is limited by means of an annular collar (not shown) thereon engaging shoulder (also not shown) formed on the inner wall of the sleeve H3. The sleeve H3 is locked in position by means of a lock nut I I7.

Upon energization of the trip device I9 the armature I09 is attracted thrusting the trip rod 91 upwardly. The trip rod, at this movement, engages the portion 95 of the auxiliary latch 05 and rocks this latch clockwise to disengage the latching projection 89 thereon from the tail 93 of the main latch 61. The upward force exerted on the operating rod 49 and the lever 53 by the breaker accelerating spring overcomes the relatively weaker spring I3 and forces the main latch 61 clockwise as the lever 53 rotates clockwis about the pivot 55 to open position. As soon as the roller 55 escapes the latch 61, the spring I3 acts to restore the latch to its latching position. When this occurs the spring 9| tends to move the auxiliary latch 85 to latching engagement with the main latch. Should this occur it is obvious that the latch roller 65 could not be restored to latching engagement with the main latch 61. In

order to prevent'theauxiliary latch from reengaging themainlatch following a tripping operation and until the mechanism is restored to. full closed position a holding, lever H9. is provided. The holdinglever II3 comprises a Urshapedlever pivotally supported on the pivot pin 81' and having the two arms thereof rigidly joined at their free ends by a cross bar I2I. Av spring I23. seated. in a spring seat in. the casting. II biases the cross bar IZ I. into contact with the latch roller 65 so that, when the, lever53' and the roller I55-move in opening directionthe spring I123 causes the holding leverv H9. to rotate in a clockwise direction about the pivot 81. Durin this movement of the holding lever a lateral extension I25 thereon engages the portion 95 of the auxiliary latch 85 and, since the spring I23 is relatively stronger thanthe spring 9I, holds the auxiliary latch in its unlatching.positionuntil the breaker'is closed;

Whenthe trip device is operated to release the operating lever 53, the accelerating spring; 52 moves the operating rod upwardly as the breaker mechanism moves to open position. Due to the connecting link 43 (Fig. 2) the piston I1 moves therewith to the top of the cylinder I5. In orderthat the piston I1 may move rapidly upwardly in the cylinder to provide for high speed interruption of the circuit the exhaust valve mechanism indicated generally at 25 (Fig. 2) is provided and is energized simultaneously with the energlzation of the trip device I9 (Fig. 1). The exhaust valve mechanism is supported on housing I21 (Figs. 1' and 2) secured to the side of the main casting II by means of bolts I29. The housing I21 is provided with a passage I3I. which is in align,- ment with an exhaust port I33 in the wall of the cylinder I5. Theexhaust passage I3 I is'normally closed by means of an electromagnetically operated piston valve I35 disposed for vertical movement in a cylinder I31 formed integral with the housing I21.

An electromagnet, indicated generally at I39 (Figs. 1 and 2-), is provided to operate the exhaust valve I35 to open position and is energized simultaneously with the trip device I9 to quickly dump the air above the piston I1 when the breaker is tripped and moved to open position. The electromagnet I39 includes a U-shaped stationary core I4I of laminated magnetic material supported by means of angular brackets I43; from the lower flanged end I44 of the cylinder I31.

The brackets I43 are secured on opposite sidesof the lower end of the stationary core I4I. Screws I45 pass through each end of each of the brackets I43, through brackets I41 secured to the upper end of the core MI and threadedly engage tapped holes in the flanged lower end I44 of the exhaust valve cylinder I31. Spacers I49 surround the screws I45 between the brackets I41 and the cylinder I31 to properly locate the magnet core.

An energizing coil II mounted between insulating members I53 is supported on the brackets I41 by means of bolts I55 passing through the members I53 and the brackets I41 and having nuts I51 (Fig. 1) on the upper ends thereof.

Spacers I59 are provided on each of the bolts I55 to space the members I53 apart. The coil I5I is provided with a suitable central opening to receive a movable core I6I oi. laminated magnetic. material pivotally supported by means of a pivot pin I63 on a yoke I65 secured to the lower end of a piston rod I61. The upper end of the rod I61 passes loosely through the head of the valve. I35,

and is headed as at I69 and operatively engages the. closed end of the cup-like piston valve I35.

The valve. I35, andthe movable core I6I are biased to the closed; position by a coil spring I1I compressed between a washer I13, supported on the brackets I4 1, and the head of the valve I35.

As: was stated previously the exhaust valve magnet I39 is energized simultaneously with the trip device I9 (Fig. 1), andwhen energized, attractsthemovable core I6I (Fig.2) drawing the valve I35 downwardly inthe cylinder I31 to open the exhaust passages; I3I. If there is any compressed. air in the, breaker operating cylinder above thepiston I1at the time the exhaust valve I35 is opened by the electromagnet I39, the compressed air will push the; exhaust valve down to its, full open, position thereby quickly dumping theair from the cylinder so that the airwill not retard: opening of the breaker. As the breaker moves to open position drawing the piston I1 upwardly in the cylinder I5, the air above the piston is quickly exhausted to the atmosphere through the relatively large passage I33-I3I.

During itsupward travel the piston I1 passes the exhaust port I33 after which the air above the piston is compressed to absorb the kinetic energy of the moving mass of the breaker. However theair thus compressed in the upper end of the. operating cylinder I5 exhauststo. the atmosphere through an air inlet passage I15 (Figs. 2 and 3) extending vertically through the upper portion 33 of the casting II and an extension I11 thereof, past the. throttle valve and through a passage I19 in the housing I8I of the inlet valve to the atmosphere. As the piston approaches the limit of its upward or opening travel, it operates the throttle; valve 23 further restricting the passage I15, as will be later described in detail, thus increasing the cushioning effect as the piston and the connected operating mechanism is brought to-rest in fully open position.

The circuit breaker may be manually tripped open by energizing the electrical circuit for the trip device I 9 and the exhaust magnet I39 by means of a manually controlled switch (not shown 'I'hecircuit breaker may be tripped open mechanicallyfln case of failure of current in the control circuit (not shown) by manually'operating the-trip rod 91 (Fig. 1) This is accomplished by operating a bell crank I (Fig. 1) pivotally supported by means of a pivot pin I82 mounted in a: bracket I84 secured to the under side of the projection 5 which supports the manual trip rod I H. Thebent end I88 of a pull rod I90 projects through an opening in an ear I92 of the downwardly extending arm of the bell crank I80 and issuitably retained in place by a cotter pin.

When itvis desired to trip the breaker mechanically the pull rod I90 is drawn toward the left (Fig. 1). which rotates. the bell crank I89 clockwise thrusting the manual trip rod and the trip rod 91 upwardly to operate the latch mechanism 21. The circuit breaker then moves to the open position, the air above the operating piston I1 be ng expelled from the cylinder through the fully openpassage I15--I19 (Figs. 2 and 3) since the exhaust magnet I39, is not energized upon mechanical operation of the trip device.

In order to close the breaker 50 compressed air is admittedto the cylinder I5 above the piston I-1 through the inlet passage I19-I15 by operation of the inlet valve mechanism 2 I. The inlet valve mechanism includes the housing IIII which is securely mounted by means of bolts I83 (Fig. 1) on the side of the extension I11 of the main casting. An inlet valve I85 disposed for vertical movement within the housing I8I, is biased to closed position by means of a spring I8? disposed in an air inlet chamber I86 and seated on a plug I88, screwed into the bottom of the housing Iill. The upper end of the spring I81 bears against the valve I85. The valve I85 is secured on a rod I9I which also carries an exhaust valve I93. When the inlet valve I85 is closed the exhaust valve I93 is open connecting the upper end of the operating cylinder I to the atmosphere through the passage I l5-I'I9 and an exhaust port I95. When the inlet valve I85 is operated to open position to admit compressed air to the cylinder I5 the valve I93 is moved to close the exhaust port I95.

The inlet valve I85 and the exhaust valve I93 are operated respectively to open position and closed position by means of an electromagnet indicated generally at I91 (Figs. 1 and 2). The magnet I5): includes a U-shaped stationary core member I99 of laminated construction supported on a plate 25H by means of angular brackets 203 suitably secured, for instance, by welding, to the core member. means of screws 265 to the plate 2GI which, in turn, is secured to the top of the inlet valve housing I8I by means of screws 20! (Fig. 2). An energizing coil 2% is mounted between insulating plates 2 II secured by means of bolts 2 I3 to angu lar brackets 2I5 welded to the upper end of the core member I99. Spacers 2I6 (Fig. 1) are provided to space the plates 2lI apart. The lower portion of the core member I99 is provided with a clearance opening (not shown) through which the valve stem I9! passes, and the coil 209 has a central opening (also not shown) in which is disposed a T-shaped movable core 2II.

The control circuits for the trip device I9 and the inlet valve electromagnet I91 are preferably the same as the control circuits disclosed in the copending application of James M. Cumming and Richard C. Cunningham, Serial No. 410,686, filed September 13, 1941, and assigned to the assignee of the present invention. The control circuits have not been shown in this case as they are not necessary for a complete understanding of the present invention. It is believed sufficient for the purpose at hand to mention that the inlet valve electromagnet may be energized in response to the operation of a manual closing control switch or automatically in response to the closing of an auxiliary switch which may be set to close at an intermediate position in the opening stroke of the breaker so as to initiate quick reclosing of the breaker. The trip device I9 is energized in response to an overload or other fault condition. For details of the control circuits reference may be had to the aforementioned copending application. As previously pointed out the exhaust valve electromagnet I39 is energized simultaneously with the trip device I9.

When the electromagnet I91 is energized, the magnet attracts the movable core 2II which thrusts the valve stem I9! downwardly closing the exhaust valve I93 and opening the inlet valve I8 The inlet air chamber I86 is connected by means of a pipe 2I9 (Fig. 1) to a source (not shown) of compressed air. When the inlet valve I85 (Fig. 2) is opened air under pressure is admitted through the passage I'I9I'I5 to the upper end of the operating cylinder I5 moving the piston I? toward the bottom of the cylinder and moving the connected breaker operating mechanism to closed position.

The brackets 203 are secured by III) The driving force required for normal closing operations where the closing movement i initiated from the full open position is much less during the first portion of the closing stroke than during the final portion of the closing stroke when the heavy contact load is being overcome, and is also much less than that required to quickly reverse the switching movement and automatically reclose the breaker after interruption of the circuit and before the breaker reaches full open position. The automatically operable valve 23 (Fig. 2) is efiective to reduce the flow of compressed air admitted to the operating cylinder during the first part of the closing stroke on nor- 1 mal closing operations, but permits the full flow of air pressure to the cylinder during the final portion of the closing stroke. The valve 23 is also efiective to permit full flow of compressed air during quick reclosing operations to provide additional power required to quickly reverse the movement of the breaker and quickly reclose the same.

The rate of flow of compressed air to the cylinder I5 to effect closing of the circuit breaker is controlled by the previously mentioned valve 23 and by an adjustable metering pin 22l (Figs. 1, 3 and 4) in an auxiliary air passage. The valve 23 includes a piston type valve 223 (Figs. 2 and 4) disposed for vertical movement in a cylinder 225 formed in the projection ll! of the main casting. The valve 223 is cup-shaped and has an operating rod 22! secured to the inside bottom portion thereof and extending vertically beyond the valve through an opening in a guide bracket 229. The bracket 229, which is secured to the top of the extension IT! by means of bolts 23l (Fig. 4), also serves as a retainer for a valve spring 233 which is coiled about the rod 221 and bears against the under side of the bracket 229 and against the inside bottom of the valve 223 to bias the valve 223 to open or non-throttling position. An operating rod 235 projects downwardly from the bottom of the valve 223 through an opening in the top of the operating cylinder I5 and extends for some distance into the cylinder where it is adapted to be engaged by the piston I'I during the opening stroke to move the valve to closed position.

The valve 223 is adapted to be moved downwardl to open position as the breaker mechanism approaches closed position by means of a tappet 23'! (Figs. 1 and 2) secured by means of bolt 239 to an angle bracket 24! which is Secured by means of welding to the adjacent operating lever 53. Shims or spacers 243 of different thicknesses may be assembled between the tappet 23'! and the bracket 24I in order to vary the div tance of the operating end of the tappet from the valve operating rod 221 thus adjustably determining the time during the closing stroke when the throttle valve 223 will be operated to open position.

The valve 223 is shown in Figs. 2 and 4 in the open position in which an annular groove 245 on the outer periphery of the valve is in alignment with the passages I75 and I19 thereby connecting these passages to admit compressed air to the operating cylinder l5. Means comprising a spring pressed ball 24'! (Figs. 3 and 4) is provided to latch the valve in its upper or closed position when it has been moved to this position by the piston II. The ball 247 is disposed in a horizontal opening in the portion ll! of the main casting and is pressed against the periphery of the valve 223 by means of a spring 249 which is rethat the valve will remain in its open position upon a quick automatic reclosing operation when tained in place by a retaining plug 25I threadedly engaging the casting. A latching groove 253 is provided near the bottom of the valve 223 and is adapted to be engaged by the ball 241 when the valve is raised to closed position, to retain the valve in closed position against the force of the spring 233.

The metering pin 22I is disposed in an opening 255 (Fig. 3) in the casting I11, which forms part of a bypass channel 251 connecting the passage I15 through an off set passage 259 to the passage I19. The metering pin 22I threadedly engages the opening 255 in the casting and is ad- I justable by rotating it in either direction to move the tapered inner end thereof relative to the channel 251 to thereby regulate the flow of air through the bypass channel around the valve 223 and independently of the valve. A look nut 26I is provided to lock the metering pin in its adjusted position.

It was stated previously that the operating piston I1 during the opening stroke moves the valve 223 to closed position. This i effected by the piston engaging the operating rod 235 and thrusting th valve 223 upwardly against the opposing force of the spring 233 until the piston arrives at the limit of its upward travel in which position the groove 253 is in line with the ball-241. The spring 249 now forces the ball 241 into the groove 253 thus latching the valve 223 in its closed position. Early in the upward movement of the valve 223 the groove 245 i moved out of alignment with the passages I and I19 thus blocking these passages and restricting the flow of air to the cylinder to the bypass channel. Thereafter, during the opening stroke of the piston I1, the air in the top of the cylinder I5 escapes to atmosphere through the

bypass channel

255, 251 and 259 under the control of the metering pin 22I. Since the bypass channel greatly restricts the'flow of air from above the piston the air remaining in the cylinder acts to cushion the blow of the breaker mechanism as it reaches full open position.

When the closing magnet I91 (Figs. 1 and 2) is energized to initiate a closing movement of the operating mechanism, it closes the exhaust valve I93 (Fig. 2) and opens the inlet valve I85. This admits compressed air from the source (not shown) through the inlet chamber I86, inlet valve I85, passage I19,

bypass channel

259, 251 and 255 (Fig. 3) and the passage I15 to the upper end of the operating cylinder I5 above the piston I1. This forces the piston downwardly and moves the connected operating mechanism toward closed position, the metering pin 22I acting to throttle the flow of air to the cylinder a predetermined amount. As the piston I1 (Fig. 2) moves downwardly in the cylinder, the lever 53 is rotated in a counterclockwise direction (Fig. 1) and, at a predetermined time during this movement, the tappet 231 engages the upper end of the valve rod 221 and moves the valve 223 downwardly to disengage it from the ball latch 241. As soon as the valve 223 is unlatched the spring 233 acts to quickly move the valve to its lower or open position in which the groove 245 is aligned with the passage I15--I19. This occurs shortly before the breaker contacts engage, thus providing an increased volume of compressed air to bring the movable contacts quickly into pressure engagement with the stationary contacts.

The valve 223 is automatically controlled by the piston l1 and the operating lever 53 according to the position of the breaker in such a manner the reclosing movement of the breaker i initiated when the breaker is in an intermediate or partially open position. This provides for the admission of a. full volume of compressed air to the operating cylinder in order to quickly reverse the movement of the operating piston and breaker operating mechanism and to operate said mechanism tofully closed position.

While the invention has been disclosed in accordance with the provisionsof the patent statutes, it is to be understood that various changes in the structural details and arrangement of parts thereof may be made without departing from some of the essential features of the invention. It is desired, therefore, that the language of the appended claims be given the broadest reasonable construction permitted in the light of the prior art.

We claim as our invention:

1. In an operating mechanism for a circuit breaker, fluidpressure operated means for closing said breaker, means including an inlet valve operable to admit fluid pressure to effect closing of the breaker, a second valve disposed in a passage connecting said valve and the fluid pressure operated closing means, said second valve being operable by the fluid pressure operated means when the breaker is moved to open position to substantially close said passage, means for restraining said second valve in closed position during a substantial portion of the closing movement, and means including an auxiliary passage for admitting a predetermined fluid pressure independently of said second valve to operate the breaker to closed position.

2.'In an operating mechanism for a circuit breakenan-operating cylinder, a piston in said cylinder for moving said breaker to closed position, an inlet valve operable to connect said cylinder to a source of air under pressure to efiect closing of the breaker, means operable to cause opening of the breaker, means for operating said valve to effect closing of the breaker, a second valve operable by the piston when the breaker is moved to open position to reduce the airpressureadmitted to said cylinder, means for holding said second valve closed for a predetermined time during the closing movement of said piston, and means comprising a bypass channel around said second valve for permitting compressed air to flow to said cylinder at a predetermined rate irrespective of the positionof said second valve.

3. In an operating mechanism for a circuit breaker, means comprising a fluid motor operable to close the breaker, an inlet valve operable to admit fluid pressure to said motor to efiect closing of the breaker, means for operating said valve to effect normal closing of the breaker from full open position, a second valve disposed in a passage connecting said valve and the fluid motor and operable by said motor when the breaker is opened to substantially close said passage, means for latching said second valve in closed position during a portion of the closing operation of said motor, means including an auxiliary passage for admitting fluid at a predetermined rate to the motor, and adjustable means in said auxiliary passage to vary the rate at which fluid is admittedto said motor.

'4. An operating mechanism for a circuit breaker comprising a fluid motor movable to open and closed positions to open and close the breaker, an inlet valve operable to admit fluid under pressure to said motor to effect closing movement of said breaker, means comprising an automatically operable valve disposed in a passage connecting said valve and the motor, said automatic valve being operable at a predetermined intermediate point near the end of the opening movement of the motor to substantially close said passage, restraining means for releasably restraining said automatic valve in closed position, an auxiliary passage bypassing said automatic valve for admitting a predetermined amount of fluid pressure to the motor to effect closing of the breaker from full open position, and means operable at a predetermined point near the end of the closing stroke to release said automatic valve and cause opening of the automatic valve to cause greater fluid pressure to be applied near the end of the closing operation than at the beginning of the closing operation.

5. An operating mechanism for a circuit breaker comprising a cylinder and a piston in said cylinder for moving said breaker to closed position, means including an inlet valve operable to connect one end of said cylinder to a source of air under pressure to close the breaker, means operable to cause opening of the breaker, means for operating said valve to eflect closing operation of the breaker, a second valve disposed in a passage connecting the cylinder to the valve, said second valve having a projection extending into the cylinder and engageable b said piston as the piston approaches full open position to substantially close said passage to reduce the air pressure applied to the cylinder on normal closing operations, means independent of said piston for restraining said second valve in said substantially closed position during a substantial portion of the closing movement, and an auxiliary passage bypassing said second valve for permitting compressed air to flow at a predetermined rate to the cylinder when said second valve is closed to effect normal closing operation of the breaker.

6. An operating mechanism for a. circuit breaker comprising a cylinder and a piston movable therein for moving said breaker to closed position, means operable to cause opening of the breaker, an inlet valve operable to connect one end of said cylinder to a source or" compressed air to close said breaker, a second valve disposed in a pasasge between the inlet valve and the cylinder, said second valve having a projection extending into said cylinder and separably engageable by the piston when the breaker nears its open position to move said second valve to closed position, a second passage for admitting a predetermined amount of compressed air to said cylinder independently or the second valve to close the breaker, and means other than said piston engageable with the second Valve at a predetermined time during the closing movement of the breaker for opening said second valve to thereby increase the amount of compressed air admitted to the cylinder near the end of the closing stroke of the breaker.

7. An operating mechanism for a circuit breaker comprising a cylinder and a piston movable therein for moving said breaker to closed position, a trip device operable to cause opening of the breaker, an inlet valve operable to connect one end of said cylinder to a source of compressed air to close the breaker, a passage connecting said inlet valve and said cylinder, a second valve disposed in said passage and operable at a predetermined intermediate point in the opening movement of the breaker to close the passage, a second passage connecting the inlet valve to the cylinder for admitting independently of the second valve a predetermined amount of compressed air to the cylinder to close the breaker, adjustable means disposed in said second passage for adjustably determining the amount of compressed air to be admitted to the cylinder to initiate the closing movement of the breaker, and means operable during the closing stroke of the breaker to cause opening of said second valve thereby increasing the amount of compressed air admitted to the cylinder near the end of the closing stroke.

8. An operating mechanism for a circuit breaker comprising a cylinder and a piston movable therein for moving said breaker to closed position, trip means operable to cause opening of the breaker, an inlet valve operable to connect one end of said cylinder to a source of compressed air to close the breaker, a second valve disposed in a passage intermediate the inlet valve and the cylinder and biased to open position, said second valve having a part projecting into the cylinder and engageable by the piston when the breaker moves to open position to actuate said second valve to close a portion of the passage to thereby reduce the amount of compressed air admitted to the cylinder during the first part of the closing movement of the breaker, restraining means to restrain the second valve in closed position, and means operable during the closing movement of the breaker to cause opening of the second valve to increase the amount of compressed air admitted to the cylinder near the end of the closing movement of the breaker.

9. An operating mechanism for a circuit breaker comprising a fluid motor for closing the breaker, an inlet valve operable to admit fluid under pressure to said motor to effect closing of the breaker, a plurality of passages connecting said valve to said motor, a valve disposed in one of said passages and operable by the motor when the breaker moves to open position to reduce the force applied to the motor to close the breaker, means disposed in another of said passages to adjustably determine the amount of force to be applied to the motor to effect the closing movement of the breaker, and means operable during the closing movement of the breaker to cause said second mentioned valve to open the first named passage to thereb increase the force applied to the motor during the latter part of the closing movement of the breaker.

10. In a circuit breaker comprising relatively movable contacts, operating mechanism for said circuit breaker comprising a fluid motor for closing said breaker, an inlet valve operable to admit fluid under pressure to said motor to eifect closing of the breaker, a plurality of passages connecting said valve and the motor, a second valve disposed in one of said passages, and operable by the motor at a predetermined time during the opening movement of the breaker to cause a reduced force to be applied to the motor through a second passage to close the breaker, means independent of said motor for restraining said second valve in said operated position during a substantial portion of the closing movement, and means operable during the closing movement of the breaker for operating said second valve to increase the force applied to the motor at a predetermined time during the closing movement.

11. An operating mechanism for a circuit breaker comprising a cylinder and a piston in said cylinder for moving said breaker to closed position, means including an inlet valve operable to connect one end of said cylinder to a source of air under pressure to close the breaker, means operable to cause opening of the breaker, means for operating said valve to effect normal closing of the breaker from full open position, a second valve disposed in a passage connecting the cylinder to the valve, said second valve having a projection extending into the cylinder and engageable by said piston as the piston approaches full open position to cause said valve to close said passage to thereby reduce the'flow of compressed air to the cylinder'on normal closing operations, means comprising a by-pass channel for permitting compressed air to flow at a predetermined rate to the cylinder when the second valve is closed to effect'normal closing operation of the breaker, and means for opening said second valve during the latter portion of the closing stroke.

12. An operating mechanism for a circuit breaker comprising a cylinder and a piston in said cylinder for moving said breaker to closed position, means including an inlet valve operable to connect one end of said cylinder to a source of gas under pressure to close the breaker, means operable to cause opening of the breaker, means for operating said valve to efiect normal closing operation of the breaker from full open position, means for controlling the rate of flow of gas to the cylinder comprising a second valve having one position in which said means permits gas to flow at a predetermined rate to the cylinder and having an open position in which said means permits gas to flow at an increased rate to said cylinder, said second valve having a projection extending into the cylinder and engageable by said piston as the piston approaches full open position to actuate said second valve to said one position, and means movable with said piston and engageable with said second valve during the latter portion of the closing stroke for initiating actuation of said second valve to open position.

13. An operating mechanism for a circuit breaker comprising a cylinder and a piston in said cylinder for moving said breaker to closed position, an inlet valve operable to connect one end of said cylinder to a source of compressed air, means operable to effect opening of the breaker, means for operating said valve to efiect normal closing of,the breaker from full open position, a second valve disposed in a passage connecting the cylinder to the valve, said second valve having a part projecting into the cylinder and engageable by the piston at a predetermined time during the opening stroke of the breaker to actuate said second valve to closed position to reduce the flow of compressed air to the cylinder on normal closing operations, latch means for latching said second valve in closed position, means biasing said second valve to open position, and means engageable with said second valve at a predetermined time during the latter part of the closing stroke to unlatch said valve and permit said biasing means to actuate the valve to open position to thereby increase the flow of compressed air to the cylinder.

14. In an operating mechanism for a circuit breaker, fluid pressure operated means for closing said breaker, means comprising an inlet valve operable to admit fluid pressure to eifect closing of the breaker, means including a valve operable to quickly reduce the pressure in said pressure operated means, electromagnetic means comprising an armature having a lost motion connection with'said valve for moving said valve a predetermined distance in opening direction to admit fluid pressure to the top of said valve, said valve being operable relative to said armature by fluid pressure to full open position.

15. In an operating mechanism for a circuit breaker, an operating cylinder, a piston in said cylinder for moving the breaker to closed position, an inlet valve operable to admit fluid pressure to said cylinder to close the breaker, means operable to cause opening of the breaker, means comprising an exhaust valve operable to exhaust thepressure in said cylinder, an electromagnet including a movable armature for initiating opening movement of said exhaust valve at least to a'point where fluid pressure is admitted to the top of saidvalve, said valve being then operated independently of said armature to its full open position by fluid pressure to quickly exhaust the pressure in said cylinder.

16. In an operating mechanism for a circuit breaker, means comprising a fluid motor operable to close the breaker, an inlet valve operable to admit fluid pressure to said motor to effect closing of the breaker, means operable to cause opening of said breaker, means comprising an exhaust valve for collapsing the fluid pressure in said motor, electromagnetic means including an armature having a lost motion connection with said exhaust valve operable to initiate an opening movement of said exhaust valve, said exhaust valve being thereafter operated by fluid pressure to full open position independently of said armature.

17. In an operating mechanism for a circuit breaker, means comprising a fluid motor operable to close the breaker, means comprising an inlet valve operable to admit fluid pressure to said motor to effect closing of the breaker, means operable to cause opening of said breaker, an exhaust passage communicating the motor to the atmosphere, a piston type valve disposed in said passage and operable to cause quick collapse of the fluid pressure in said motor during a breaker opening movement, means for moving said valve a predetermined distance in opening direction, said valvebeing thereafter moved to full open position by fluid pressure, a second passage communicating the motor to the atmosphere, a valve disposed in said second passage, said valve being operable by the motor near the end of the opening movement of the breaker to restrict said second passage to thereby cushion the opening movement of the breaker.

18. In an operating mechanism for a circuit breaker, fluid pressure operated means for closing the breaker, valve means operable to admit fluid pressure to effect closing of said breaker, a second valve disposed between said valve means and said fluid pressure operated means, said second valve being biased to open position and operable to a closed position, means for operating said second valve to closed position, latch means for holding said second valve in closed position against its bias, and means operable at a predetermined time during a closing operation to operate said latch means and permit movement of said second valve to open position.

19. In an operating mechanism for a circuit breaker, fluid pressure operated means for closing the breaker, an inlet valve operable to admit fluid pressure to effect closing of the breaker, a second valve disposed between said inlet valve and said fluid pressure operated means, means biasing said second valve to open position at all times, means operable during an opening operation of said breaker to move said second valve to closed position against said biasing means, latch means for releasably holding said second valve in closed position, and means operable during a closing operation to release said second valve and permit said biasing means to move said valve to open position.

20. In an operating mechanism for a circuit breaker, a fluid motor operable to close the breaker, an inlet Valve operable to admit fluid pressure to said motor to efiect closing of said breaker, valve means disposed between said inlet valve and said motor for controlling the flow of pressure to said motor, means at all times biasing said valve means to open position, means for operating said valve means to closed position, a ball type latch engageable with said valve means for releasably holding said valve means in closed position, and means operable at a. predetermined time during a closing operation to release said valve means and permit said biasing means to move said valve means to open position. 21. In an operating mechanism for a circuit breaker, a fluid motor for closing said breaker, a valve for controlling the admission of fluid pressure to said motor, spring means at all times biasing said valve to open position, means operable at a predetermined time during an opening movement of said breaker to move said valve to closed position, latch means for engaging and releasably restraining said valve means in closed position, and means operable at a predetermined time during a closing operation of said breaker to release said valve means and permit said spring means to quickly move said valve means to open position.

JAMES M. CUMMING.

HENRY L. PEEK.