US2752536A

US2752536A - Pneumatically operated circuit breaker with selective air cut-off

Info

Publication number: US2752536A
Application number: US294154A
Authority: US
Inventors: Ralph O Bonine; Willard T Parker
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1952-06-18
Filing date: 1952-06-18
Publication date: 1956-06-26
Anticipated expiration: 1973-06-26

Description

June 26, 1956 R. o. BoNlNE ET AL PNEUMATICALLY OPERATED CIRCUIT BREAKER WITH SELECTIVE AIR CUT-OFF 3 Sheets-Sheet 1 Filed June 18, 1952 INVENTORS WITNESSES: 1I

June 26, 1956 R, o. BQNINE ET AL 2,752,535

PNEUMATICALLY OPERATED CIRCUIT BREAKER WITH SELECTIVE AIR CUT-OFF Filed June 18, 1952 3 Sheets-Sheet 2 L@ Fig.2.

WITNESSES:

INVENTORS Rolph 0.8onine ondYWillord T.Porker MNM United States Patent O PNEUMATICALLY OPERATED CIRCUIT BREAKER WITH SELECTIVE AIR CUT-OFF Ralph O. Bonine and Willard T. Parker, Pittsburgh, Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application June 18, 1952, Serial No. 294,154

6 Claims. (Cl. 317-59) This invention relates to circuit breakers and more particularly to circuit breaker operating mechanisms of of the pneumatic type.

An object of the invention is to reduce the reclosing time of an automatic-reclosing circuit breaker.

Another object of the invention is to provide an improved uid-pressure-operated circuit breaker operating mechanism which is trip free and capable of effecting high-speed opening and quick reclosing of the circuit breaker.

Another object of the invention is to provide a circuit breaker operating mechanism operable by fluid pressure in which means is provided to admit fluid pressure to the operating mechanism early in an opening operation to quickly reverse the moving parts and reclose the breaker before the breaker reaches full open position.

Another object of the invention is to provide an improved circuit breaker having a uid motor operating mechanism including means for controlling the admis- Sion of compressed fluid to the motor early in an opening operation of the breaker to quickly reverse the moving parts and reclose the breaker and also including means for cutting ott the compressed iluid to the motor early in a closing operation to conserve compressed fluid.

Another object of the invention is to provide an improved circuit breaker of the pneumatically operated type having a trip-free tripping means, a non-trip-free tripping means and means responsive to the condition of the closing means for causing compressed air to be admitted to the operating means early in a non-trip-iree opening operation to effect quick reversal of the moving parts and quick reclosure of the breaker.

Another object of the invention is to provide a circuit breaker having a lluid-pressure-operated closing means, a trip-free latch means, a non-trip-free latch means and fluid-pressure-operated means responsive to the condition of the closing means for selecting which of the latch means shall be operated to effect tripping of the breaker in response to a fault condition.

Another object of the invention is to provide a circuit breaker with an improved operating mechanism of the pneumatic type capable of etecting high-speed operation of the circuit breaker and operating piston, quick reversal of the moving parts and quick reclosure of the breaker.

Another object of the invention is to provide a circuit breaker with an improved operating mechanism of the pneumatic type capable of effecting high-speed opening and quick reclosing of the circuit breaker upon initial opening thereof by a fault condition.

A further object of the invention is to provide a circuit breaker embodying power-operated closing means with means responsive to the energized condition of the closing means to effect energization of the closing means early in an opening operation of the breaker to effect quick reversal of the moving parts and quick reclosure ot the breaker.

ICC

A further object of the invention is to provide a circuit breaker embodying power-operated closing means with means for effecting energization of the closing means early in an initial opening of the breaker by a fault condition to effect high-speed reversal of the moving parts and quick reclosure of the breaker before the breaker reaches full-open position.

The invention both as to structure and operation, together with additional objects and advantages thereof, will be best understood from the following detailed description of several embodiments thereof when read in conjunction with the accompanying drawings.

In said drawings:

Figure l is a side elevational View of a circuit breaker operating mechanism embodying the principles of the invention;

Fig. 2 is a vertical sectional view taken substantially on line II-II of Fig. 1 and looking in the direction indicated by the arrows;

Fig. 3 is a sectional view taken on line III-III of Fig. l showing the valve mechanism for controlling the admission of fluid pressure to the operating cylinder;

Fig. 4 is a sectional view taken on line IV-IV of Fig. 3 showing the throttle valve and the piston for operating the trip selector mechanism;

Fig. 5 is a schematic diagram of the circuit for controlling the circuit embodying one form of this invention;

Fig. 6 is a modification of the invention shown in Fig. 5.

The invention is illustrated as applied to a circuit breaker operating mechanism fully disclosed in application Serial No. 232,776, tiled June 2l, 1951 by R. C. Van Sickle and assigned to the assignee of the instant application, now Patent No. 2,656,430.

Referring to Fig. 2 of the drawings, the circuit breaker 11 which is illustrated diagrammatically, may be of any conventional construction either oil-break, air-break or gas-blast type and is adapted to be operated to the open position by means of an accelerating spring 13. The circuit breaker is adapted to be operated to the closed position by means of an operating mechanism which in the embodiment shown is of the compressed-fluid type. The operating mechanism includes an operating cylinder 17 closed at its upper end by a plate 19 and at its lower end by a bottom plate 20 secured together by means of bolts 21 (Fig. 1). Mounted in the operating cylinder 17 (Fig. 2) is an operating piston 23 having secured thereto a piston rod 25 which is slidable through a substantially air-tight opening in the plate 19. Rigidly secured to the upper end of the piston rod 25 is a coupling 27 which is releasably connected to a coupling 29 rigidly secured to a breaker operating rod 31 by means of an inverted toggle comprising

toggle links

33 and 35. The breaker operating rod 31 is operatively connected to the circuit breaker 11 by means of a suitable linkage.

The toggle link 33 comprises a pair of spaced parallel links pivotally connected by means of a pivot pin 37 to the coupling 27. The toggle link 35 comprises a single link disposed betwen the links 33 and is pivotally connected by means of a pivot pin 39 to the coupling 29. The

toggle links

33 and 35 are pivotally connected together by means of a knee pivot pin 41.

In order to provide for straight-line movement of the piston rod 25 and the breaker operating rod 31, and to assist the trip-free toggle 33-35 in maintaining the breaker closed, the pivot pins 37 and 39 are provided with rollers 43 and 44, respectively, there being a roller 43 mounted on each end of each of the pivot pin 37 and a roller 44 mounted on each end of the pin 39. These rollers cooperate with corresponding vertical slots 45 Vis pivotally mounted on a pin 55y supported in the frame members 47 and is biased by means Vof a spring-pressed plunger 57 into latching engagement with a latch member 59 on the coupling 27. The plunger 57 is slidably mounted on a rod 58 mounted on a cross bar 61 rigidly supported between the frames 47 and is biased by means of a compression spring 63. The main latch 51 is pro- `vided with a latching: surface 67 for cooperating with the latch member 59 on the coupling 27 and also has a projection, 69 carrying a latch roller 70 for cooperating with latching mechanism 53.

The light-load latching mechanism 53 includes an un- .der-set tripping toggle comprising

toggle links

71 and 73, a trip-free trigger latch 75 cooperating to releasably maintain the tripping toggle in its under-set position and a non-trip-free latch 76 cooperating with the latch roller -70 on the main latch 5 1. The toggle link 71 comprises a pair of links rigidly joined by a cross member 77 and are pivotally mounted on a fixed pivot pin 79 supported by the frame members 47. At their free ends the toggle links 71 carry between them a latch roller 81 with which 4the trigger latch 75 cooperates to maintain the tripping toggle 71-73 in its under-set position. The toggle link 73 comprises a pair of spaced parallel links disposed one .on each side of the link 71 and pivoted on the knee pivot ,pin 41 of the trip-free toggle 33-35 outside of the toggle links 33. The toggle links 73 are pivotally connected to the toggle link 71 by means of a knee pivot pin 83.

The trip-free latch 75 and the non-trip-free latch 76 are pivotally mounted on a pivot pin 85 supported in a pair of spaced brackets 86 and 87 (Fig. l) which in turn are rigidlyl secured to a cross plate 89 mounted on the frame members 47. Mounted on the underside of the .cross plate 89 is a tripping electromagnet 91 comprising a fixed magnet yoke 93, an energizing winding 95 and a Vmovable armature 97. A` trip rod 99 is secured to the armature 97 and extends upwardly through an opening in ,the magnet and through an opening in the plate 89, the upperend of the rod 99 being disposed beneath a latch selector 1,01.

Al spring 103 compressedV between the cross plate 89 and a spring guide 104 pivotally connected to the non- 4trip-free latch 76 biases this latch to latching position against a stop 106 mounted in the

brackets

86 and 87. A similar spring (not shown) is provided to bias the trip-free latch 75 to latching position against a cross bar ,105 disposed between the side members of the toggle link 71. The under-set position of the tripping toggle 71-73 is adjustably determined by means of an adjustable stop screw 107 threadedly mounted in a cross bar 109 rigidly supported between the frames 47 and locked in adjusted position by a lock nut 111.

A latch checking switch 1,13 (Fig. 2) is provided for checking the position of the trip-free latch 75. The switch 113 is mounted on the cross plate 89 and the contacts (not shown) are controlled by a plunger 115 which is engaged by an arm 119 of the trip-free latch 75 when the latch is in latching position.

The latch or trip selector bar 101 (Fig. l) is pivotally Vconnected at its right-hand end to the upper end of a channel-shaped lever 121 by means of a pin 123 carried by the side members of the lever 121 and extending through a suitable opening in a boss 125 on the selector bar 101. The lever 121 is pivotally mounted on a pin 127 (Figs. l and 4) supported on a bracket 129 (not shown) supported in the frame 47. The lever 121 is retained in position on the pin 127 by means of a nut 133. A spring (Fig. l) compressed between the frame member 47 and the lever 121 below the pin 127 biases the lever 121 in a counterclockwise direction to the position shown in Fig. l wherein a projection 137 on the left-hand end of the selector bar is positioned beneath a tail 139 of the non-trip-free latch 76 and a second projection 141 on the selector bar is positioned out of alignment to the left of the arm 119 of the trip-free latch 75. The selector bar 101 extends. through and is guided by a slot in the bracket 87 (Fig. l). A pin 145 mounted in the bracket 87 and extending across the slot 143 above the selector bar 101 serves to hold the selector bar 101 in place.

With the selector bar 101 in the position shown in Fig. l, operation of the tripping electromagnet 91 causes the trip rod 99 to move upwardly moving the selector bar 101 upwardly. Since the projection 137 on the selector bar 101 is, at this time, positioned beneath the tail 139 of the non-trip-free latch 76, this latch will be actuated to trip the breaker and the breaker will go to the open position without disconnecting the breaker mechanism from the piston 23. However, if the selector bar 101 is shifted to the right (Fig. l), by means and under conditions to be hereinafter described, the projection 137 will be moved out from under the tail 139 of the nontrip-free latch 76 and the projection 141 will be positioned beneath the arm 119 of the trip-free latch 75. Consequently, operation of the tripping magnet 91 with the selector bar 101 in this position will actuate the tripfree latch and trip the breaker free of the closing means.

Referring to Fig. 2 of the drawings, in the closed position of the breaker, the latch 51, which is held in latching position by the non-trip-free latch 76, holds the piston 23 in the closed position in which it is shown against the force exerted by accelerating spring 13 and the force of a compression spring 147 compressed between the bottom of the piston 23 and a disc 149. The disc 149 lis suitably secured to a cylindrical member 151 as, for instance by welding, and the member 151 has secured thereto a ring 153 supported on certain of the bolts 21 which fasten the bottom plate 20 of the operating cylinder in place. The latch 51 is of the slip-off type, that is, the latch 51 is so constructed and arranged with respect to the latch member 59 that lit will not itself hold the piston rod down or in the closed position against the biasing forces of the spring 147. The relative positions of the parts are such that the upward thrust of the spring 147 applies a small component of the force through the latch roller 70 to the non-trip-free latch 7 6.

The accelerating spring 13 applies an upward force on the breaker operating rod 31, and, since the pivot pins 37 and 39 are constrained by the slots 45 to move in a straight line, a small component of this force is applied through the link 35 to the tripping toggle 71-73. Due to the tripping toggle being only slightly under set, a very small component of the force of the accelerating spring is applied through the tripping toggle 71-73 and the latch roller 81 to the trip-free latch 75.

Assuming the breaker to be in the closed position, it is tripped open by the non-trip-free latch means in the following manner:

When the tripping electromagnet 91 is energized from a suitable source, the armature 97 moves the trip rod 99 upward to engage and move the selector bar 101 upwardly. This movement of the selector bar 101 causes the projection 137 thereon to engage the tail 139 and actuate the non-trip-free latch 76 counterclockwise (Fig. 2) to unlatching position. This frees the latch 51 and the accelerating spring 13, together with the spring 147, moves the latch 51 to unlatching position and operates the breaker to the open position. During the non-tripfree opening movement, the main toggle 33-35 is held in thrust transmitting position by the toggle link 73 which,

due to the fact that the toggle link 71 is held in the position shown in Fig. 2, moves clockwise about the pin 83 as a iixed pivot. The result is that the breaker operating rod 31 and the piston rod 25 move upwardly as a unit, the breaker going to the open position and the piston 23 being moved to the upper end of the cylinder 17.

The circuit breaker is closed by admitting compressed gas to the operating cylinder above the piston 23 which forces the piston downwardly, drawing the toggle link 33 therewith. Since the toggle link 71 of the tripping toggle is held in the position shown in Fig. 2 by the tripfree latch 75, the link 73 again pivots about the pivot pin 83 which acts as a fixed pivot, thereby holding the main toggle in thrust transmitting position during the closing operation. The closing force applied to the link 33 is, therefore, transmitted through the link 35 to move the breaker operating rod downwardly and close the breaker.

Under certain conditions, to be described later, the lever 121 (Fig. l) is rotated clockwise about its pivot and draws the latch selector bar 101 toward the right. This moves the projection 137 from beneath the tail 139 of the non-trip-free latch 76 and positions the projection 141 beneath the arm 119 of the trip-free latch 75. With the parts in this position, operation of the tripping electromagnet 91 causes the projection 141 to engage the arm 119 (Fig. 2) and actuate the trip-free latch 75 to unlatching position. This releases the under-set tripping toggle 71-73 and the force of the accelerating spring 13 applied to the tripping toggle immediately causes collapse of this toggle. As soon as the tripping toggle 71-73 starts to collapse, the breaker operating rod 31 moves upwardly free of the piston 23 to open the breaker free of the closing means.

In order to restore the toggle 33 35 to thrust transmitting position to thereby recouple the breaker to the closing means, it is necessary to release the latch 51 which permits the spring 147 to move the piston 23 and the piston rod upwardly. This is accomplished by means of a projection 155 (Fig. 2) on the trip-free latch 75 which, after a predetermined movement of the trip-free latch in unlatching direction, engages and moves the non-tripfree latch 76 to its unlatching position. This permits the bias of the spring 147 to force the latch 51 to unlatching position moving the piston 23 and piston rod 25 upwardly. Since the pivot pins 37 and 39 are constrained by the slots 45 to travel in a straight line, the upward movement of the toggle link 33 will cause the link 35 to rotate counterclockwise about the pivot 39 toward the normal inverted or thrust transmitting position of the toggle 33-35 This action through the knee pin 41 and the link 73 moves the link 71 about its pivot 79 far enough to permit reengagement of the trip-free latch 75 under the latch roller 81. This restores the main toggle to thrust transmitting position and thereby eieetivey recouples the piston rod 25 to the breaker operating rod 31 in preparation for a closing operation.

Compressed gas is admitted to the cylinder 17 to close the circuit breaker by means of an inlet valve device indicated generally at 161 (Figs. l, 3 and 4). The inlet valve device comprises a main housing 163 secured to the top of the upper plate 19, which closes the upper end of the cylinder, by means of bolts 165 (Fig. l). The housing 163 has a cylinder 167 formed therein which is closed at its upper end by a closure member 168 secured thereto by means of bolts 185 and in which is disposed a valveoperating piston 169. A valve rod 171 having a valve element 173 secured to the lower end thereof extends upwardly through a guide bearing 175 into the cylinder 167 and cooperates with the piston 169. The valve element 173 is secured to the valve rod 171 by means of a nut 177 and the valve is biased upwardly to closed position Where it is seated against an annular valve seat by a spring 179 compressed between a closure plate 181 and the valve element 173.

A high-pressure chamber 187 in the housing 163 below .the valve 173 is supplied with fluid under pressure from a suitable source by means of a pipe 189 (Figs. l and 4). An inlet port 191 above the valve 173 communicates with the operating cylinder 17 by means of a passage 192 (Fig. 4) formed by a portion 193 (Figs. l and 4) of the housing 163 and a corresponding opening in the plate 19. The inlet valve 173 is operated to the open position by admitting uid under pressure from the high-pressure chamber 187 to the cylinder 167 above the piston 169 which forces the piston 169 downward in the cylinder 167 and through the valve rod 171 moves the valve 173 downward against the bias of the spring 179 and the high-pressure iluid in the chamber 187.

Fluid pressure is admitted to the cylinder 167 above the piston 169 by means of an electromagnetically operated pilot valve device indicated generally at 195 (Figs. l and 3). The pilot valve device comprises a housing 197 secured by means of bolts 199 to the housing 163 of the inlet valve device. The housing 197 is provided with a chamber 201 communicating with the high pressure chamber 187. A valve 203 normally closes off the chamber 201 from a passage 205 communicating with the cylinder 167 above piston 169. The valve 203 is biased to closed position by means of a suitable spring and is secured on a rod 207 which is attached to the armature (not shown) of an electromagnet 209. Also attached to the rod 207 is a normally open exhaust valve 211 which closes upon opening of the valve 203 to close a passage communicating the passage 205 to atmosphere.

Formed in the housing 163 is a cylinder 213 in which is disposed a cup-shaped exhaust valve 215 (Fig. 3) for controlling a large exhaust port 217. The valve 215 has a reduced portion 219 disposed in a cylinder 221 which is communicated by means of a passage 223 with the cylinder 167 and the passage 205. The cylinder 213 above the valve 215 is normally at atmospheric pressure by virtue of one or more holes in the valve. The exhaust valve 215 is normally biased by means of gravity or a suitable spring (not shown) to the closed position where it is seated on a beveled annular valve seat 225 which is secured to the housing 163 by means of a ange and bolts 227. A chamber 229 surrounding the valve seat 225 and the lower portion of the valve 215 communicates with the passage 192 by means of a large passage 231 (Fig. 6).

When the electromagnet 209 is energized (by the circuit shown in Fig. 5), the rod 207 is moved downwardly closing the exhaust valve 211 and opening the valve 203, thereby admitting fluid under pressure from the high-pressure chamber 187 through the passage 205 to the cylinder 167 above the piston 169. The iluid pressure forces the piston 169 down moving the rod 171 and inlet valve member 173 to open position to thereby admit iiuid under pressure through the inlet port 191 and the passage 192 to the operating cylinder 17 to close the breaker in the previously described manner.

At the same time compressed iluid is admitted to the cylinder 167 to open the inlet valve 173, compressed fluid is also admitted through the passage 223 to the cylinder 221 above the portion 219 of the exhaust valve 215 in order to maintain the exhaust valve closed during the closing operation of the breaker.

When the electromagnet 209 is deenergized at the end of the closing operation, the valve 203 closes and the valve 211 opens to vent the high-pressure iiuid from the cylinder 167 to permit the spring 179 to close the inlet valve 173. At the same time, the high-pressure fluid is vented from the cylinder 221 through the passages 223 and 205 whereupon the closing charge of high-pressure iiuid in the operating cylinder 17 and in the chamber 187 blasts the exhaust valve 215 to the open position to dump the compressed uid from the operating cylinder 17. As soon as the closing charge of compressed uid is cxhausted from the operating cylinder, the exhaust valve 215 is restored to its closed position by gravity or other biasing means (not shown).

7 When the breaker arrives at its fully closed position, the spring 63 (Fig. 2) moves the latch 51 into engagement with the latch member 59 on the coupling 27 to hold the mechanism and the breaker in the closed position.

If there is no fault condition such as an overload or short-circuit in the main circuit at the time the contacts are closed, the circuit breaker will be latched in its closed position as just described. However, if there is a fault condition on the main circuit at the time the circuit breaker completes the main circuit, the trip device 91 will be immediately energized and trip the breaker free of the 'closing mechanism by actuating the trip-free latch 75.

It was set forth previously that under certain condi- ,tions the lever 121 (Fig. l) was rotated clockwise from the position shown to Withdraw the projection 137 from beneath the tail 139 of the non-trip-free latch 76 and p0- sitions the projections 141 of the latch selector bar 101 beneath the arm 119 of the trip-free latch 75 in order to effect trip-free tripping of the breaker. Referring to Fig. 4 of the drawings, it will be seen that a small cylinder 233 is formed in the valve housing 163 and a piston V23S is disposed for movement therein. A passage 237 is provided to communicate the cylinder 233 Yback of the piston 235 with the inlet port 191 (see also Fig. 3). A rod 239 attached to the piston 235 extends through an opening in a nipple 241 threaded into the open end of a cylinder 233. The outer end of the rod 239 is disposed adjacent the lower end of the lever 121 and the spring 135 which normally maintains the lever 121 and the selector bar 101 in the positions shown also acts through the lever 121 and rod 239 to normally hold the piston 235 at the inner end of the cylinder 233.

When the inlet valve 173 is operated to admit fluid pressure through the inlet port 191 to the cylinder 17 to close the breaker, huid pressure is admitted through the passage 237 (Figs. 3 and 4) to the cylinder 233 and moves the piston 235 upwardly as viewed in Fig; 4 and toward the left as viewed in Fig. l. This movement of the piston 235 thrusts the rod 239 outwardly and 'rotates the lever `12.1 clockwise 'to position the latch selector bar 101 for operating the trip-free latch 75 as previously set forth. In this manner, the trip-free latch is selected whenever the breaker closes in against a fault condition with the closing charge of high-pressure uid in the operating cylinder.

When the inlet valve 173 closes and the exhaust valve 215 opens to du'mp the closing air from the operating cylinder, the bias of the spring 135 restores the lever 121 and the selector bar 101 to the positions shown in Fig. l and moves the piston 235 to the inner end of the cylinder Means is provided for preventing tripping movement of the latch selector bar 101 by the tripping magnet when the selector bar i's in an intermediate position. During the horizontal movement of the selector bar 101 from one of its selected positions to the other, there is a relatively short space in which the

projections

137 and 141 are out of alignment with the tail 139 and the arm 141, respectively. If, when the selector bar 101 is in this position and is being adjusted, the tripping electromagnet 91 'is energized, the trip rod 99 will move the selector b'ar to a position where the longitudinal movement of the bar would cause one or the other of the projections 137-141 to engage the side of the tail 139 or of the arm 119 depending on the direction of movement of the selector bar which could result in possible jamming or damage to the parts.

This condition is prevented by the provision of a projection 242 (Fig. l) on the selector bar 101 which, during that intermediate portion of the selecting movement when the

projections

137 and 141 are out of alignment respectively with the tail 139 and the 'arm 119, is

' directly below the 'pin 145 thus preventing upward or tripping movement of the selector bar 101. A slight Y 8 movement of the selector bar from this position will position the projection 137 beneath the tail 139 or the projection 141 will be positioned beneath the arm 119 depending on the direction of movement of the bar.

An automatic throttle device is provided which is effective to throttle the flow of compressed fluid to the operating cylinder during the rst part of the closing stroke of the operating piston on closing operation of the circuit breaker started from the full open or non-throttling position during the latter portion of the closing stroke to permit compressed uid to ow to the operating cylinder at an increased rate during the nal portion of the closing stroke. Fluid under pressure is admitted at a relatively slow rate by throttle device during the first part of the closing operation to decrease the tendency of the operating mechanism to slam. A larger quantity of compressed fluid is admitted to the operating cylinder by the throttle device during the nal portion of the closing stroke, thereby providing suticient driving power to overcome the relatively heavy contact load during the iinal portion of the closing stroke.

The automatic throttle means is fully disclosed and described in the aforementioned application Serial No. 232,- 776 to which reference may be made for a complete understandng thereof. Described briefly, the throttle means comprises a throttle valve element 243 (Fig. 4) disposed to control an opening 249 in a partition wall 251 which separates the inlet part 191 from a chamber 253 communicating with the operating cylinder 17. The throttle valve 243 is biased to close the opening 249 by a spring 247 and is operated to the open position by a lever 265 (Fig. l) which is actuated by the operating mechanism according to the open or closed position of the breaker. When the breaker is in the open position the throttle valve 243 is in the throttling or closed position and upon movement of the breaker to the closed position the throttle valve is moved to the open position by means of a lever 265 to increase the tlow of compressed fluid to the operating cylinder during the nal portion of the closing stroke.

Referring to Fig. 5 of the drawings, which diagrammatically shows the circuits for controlling the inlet valve electromagnet 209 and the tripping electromagnet 91, the winding of the electromagnet 209, which controls the admission of iluid pressure to the operating cylinder 17 for closing the breaker, is connected in an energizing circuit extending from a supply line 267 through a conductor 269, contacts 271 of a release relay 273, conductor 275, auxiliary contacts 277, the winding of the valve magnet 209, conductors 279, and through contacts 281 of a closing relay 283 to a supply line 285.

The energizing winding of the closing relay 283 is connected in an energizing circuit extending from the supply line 267, the conductor 269, conductor 287, back contacts 289 of the release relay 273, the winding of the closing relay 283, contacts 284 of the latch check switch 113, a conductor 291 and through the contacts of a manual closing switch 293 to the supply line 285.

The winding of the release relay 273 is connected in an energizing circuit extending from the supply line 267, a conductor 295, auxiliary contacts 297 on the breaker operating mechanism, adapted to be closed when the breaker reaches closed position, the winding of the release relay 273, conductor 299, contacts 301 of the closing relay and a conductor 303 to the supply line 285.

A stick circuit is provided for maintaining the closing relay 283 energized following a momentary operation of the manual closing switch 293. This circuit extends from the supply line 267, conductor 269, conductor 287, contacts 289 of the release relay 273, winding of the closing relay 283, conductor 305, contacts 301 of the closing relay 283 and conductor 303 to the supply line 285. A stick circuit is also provided for maintaining the release relay '273 energized until the manual closing switch 293 is released. This holding circuit extends from the supply line 267, conductor 269, contacts 307 of the release relay 273, coil of the release relay,

conductors

299 and 305, contacts 284 of the latch check switch 113, conductor 291 and the contacts of the manual closing switch 293 to the supply line 285.

The circuit for energizing the tripping electromagnet 91 extends from the supply line 267, contacts 309 of a fault responsive relay 311, conductor 313, auxiliary contacts 315 on the breaker mechanism, conductor 317, coil 95 of the tripping clectromagnet 91 and a conductor 319 to the supply line 285. A manual opening switch 320 is connected in the circuit in parallel relation with the contacts 389 of the fault responsive relay 311 in order to elfect manual opening of the breaker.

Operation of the fault relay 311 closes the contacts 309 to effect energization of the tripping magnet 91 over the circuit from line 267, contacts 309, conductor 313, auxiliary contacts 315, conductor 317, coil 95 of the tripping magnet 91 and the conductors 319 to the line 285. If the breaker has been standing in the closed position and there is no pressure in the cylinder 17, the projection 137 (Fig. l) on the selector bar 101 is in the position shown in line with the non-trip-free latch 76 and the breaker will be tripped open non-trip-free of the closing means in the previously described manner.

The circuit breaker is closed from the full open position by momentary closure of the manual closing switch 293. Closure of this switch effects energization of the closing relay 283 over the circuit from the line 267,

conductors

269 and 287, back contacts 289 of the release relay 273, coil of the closing relay 283, contacts 284 of the latch check switch, conductor 291 and the contacts of the manual closing switch 293 to the line 285. Energization of the closing relay 283 closes its contacts 281 to energize the inlet valve magnet 209 over the circuit from the line 267; conductor 269, back contacts 271 of the release relay 273, conductor 275, auxiliary contacts 277 which are closed when the breaker is open, coil of the inlet valve magnet 209, conductor 279 and the contacts 281 of the closing relay to the line 285. Operation of the closing relay 283 closes its contacts 301 to set up a stick circuit and also energizes the release relay 273, upon closing of the contacts 297, and effects opening of the

contacts

271 and 289 which respectively drop out the inlet valve magnet 209 and opens the circuit through the winding of the closing relay 283. Operation of the release relay 273 closes its contacts 307 to set up its stick circuit. Deenergization of the coil of the closing relay 283 causes opening of the contacts 301 which deenergizes the release relay 27 3. The parts are now in their normal condition with the circuit breaker in the closed position. If there is no fault condition present when the breaker is closed, the mechanism will be relatched and the breaker restrained in the closed position.

If the circuit breaker closes in against a fault condition, it will be immediately tripped open by the trip-free trip device since at this time the high pressure closing charge of fluid pressure is present in the operating cylinder and the projection 141 (Fig. 1) on the selector bar 101 is in position beneath the tail 119 of the trip-free latch 75. Under this condition the breaker will go to the full open position. The retrieving spring 147 (Fig. 2) will function in the previously described manner to reset and relatch the mechanism so that the breaker will be connected to the piston 23 in readiness for a closing operation.

The closing operation of the circuit breaker may be initiated automatically by means of a recloser, indicated generally at 321 (Fig. following an opening operation. The recloser 321 may be of a well known type which automatically effects a single high-speed reclosing operation followed by one or more quick reclosing operations when the breaker opens trip-free of the closing means. A manually operable switch 323 is provided for effecting energization of the recloser 321 or preventing quick automatic reclosing if automatic reclosing is not desired.

Assuming that the switch 323 is closed the automatic reclosing operation is etfected by the recloser 321 which upon closure of auxiliary contacts 327 momentarily closes a circuit for energizing the closing relay 283. This circuit extends from the line 285, switch 323, recloser 321, a conductor 325, auxiliary contacts 327 on the breaker operating mechanism closed during the opening operation, a conductor 329, contacts 284 of the latch check switch 113, coil of the closing relay 283, contacts 289 of the release relay 273, and

conductors

287 and 269 to the line 267. This energizes the closing relay 283 which closes its contacts 281 to energize the inlet valve magnet 209 and the closing operation is thereafter effected in the previously described manner.

If there is no fault on the circuit controlled by thebreaker when the breaker closes it will be latched up and remain in the closed position. However, if the breaker closes in against a fault, the closing air is still in the operating cylinder and the breaker will be tripped open.A by the trip-free latch 75 and the breaker will open freev of the closing mechanism. After the inlet valve magnet- 209 is dropped out and the closing air is dumped from:

the closing cylinder, the spring 147 moves the piston 23- to reset the toggle 33-35 and reset and relatch the trip-- free tripping toggle 71-73. This movement of the mech-- anism closes the auxiliary contacts 327 to set up the auto-- matic reclosing circuit, but, since operation of the trip-freey latch 75 actuated the latch check switch 113 to open its'y contacts 284, the closing relay 283 will not be energized until the resetting and relatching operation is completed and the latch 75 is restored to its latching position. Wheir this occurs, the contacts 284 of the latch check switch: are closed and the closing relay is energized over the circuits prepared by the auxiliary contacts 327 and the recloser 321 to effect automatic closing of the breaker.

In the operation of the circuit breaker it is desirable to cut 0E the flow of air pressure from the storage reser- Voir to the operating cylinder as soon as practical after the mechanism has closed and latched the breaker in order to conserve the amount of compressed air used for each closing operation and to provide the maximum number of closing operations from a reservoir of cornpressed air. This is normally accomplished on operations following a trip-free tripping operation by the auxiliary contacts 277 (Fig. 5) which are connected directly in the circuit for the inlet Valve magnet 209 and are operated by the piston. The contacts 277 are arranged to close relatively late in the opening stroke of the piston to permit retrieving and relatching of the mechanism and consequently open early in the closing stroke thus cutting olf the air supply to the operating cylinder early in the closing stroke.

When the circuit breaker is tripped by the non-trip-free latch 76 (Figs. l, 2 and 5) it is necessary to admit the closing air very early in the opening stroke of the breaker in order to obtain very high speed reclosing on the rst reclosure. The cut-olf contacts 277, however, close too late in the opening stroke to accomplish the desired highspeed reclosure. In order to overcome this difficulty and provide very high-speed reclosure following a non-tripfree tripping operation a normally closed pneumatically operated switch 331, shown schematically in Figs. 1 and 5 is provided. The contacts 333 of this switch are connected in the circuit (Fig. 5) in parallel relation with the cut-olf contacts 277 and are responsive to the air pressure in the operating cylinder 17.

As previously described, the spring (Fig. 1) biases the lever 121 to the position shown, when there is no air pressure in the cylinder 17, to position the projection 137 on the trip selector bar 101 beneath the tail 139 of the non-trip-free latch 76. In this position of the lever 121 and selector bar 101 the contacts 333 of the switch 331 are biased closed by a spring 335. The contacts 333 could also be operated by means of a separate small cylinder 337 (Fig. 5) having a piston 339 therein biased 1 1 closed by a spring 341 and having a tube 343 connecting the cylinder 337 on the Working side of the piston 339 to the operating cylinder 17 on the Working side of the piston 23.

The operation of the contacts 333 is the same with either the Fig. l or Fig. construction, that is, the contacts are normally closed and are opened upon the admission of closing air pressure to the operating cylinder 17. In the Fig. l construction admission of compressed air to the operating cylinder to close the breaker causes operation of the piston 235 (Fig. 4) to actuate the lever 121 (Fig. l) for the purpose of moving the selector bar 101 to the position to select the trip-free latch for operation. Movement of the lever 121 eiects opening of the contacts 333. Closing air presure admitted to the operating cylinder is admitted through the tube 343 (Fig. 5 to the small cylinder 337 on the working side of the piston 339 Which is thereby moved to elfect opening of the contacts 333.

With the breaker standing in the closed position and no closing air in the operating cylinder, the contacts 333 are closed shunting the open contacts 277, consequently when the breaker is tripped open under these conditions the non-trip-free latch 76 will be operated and the breaker will move in the opening direction Without being disconnected from the operating piston 23. When the breaker has moved a very short distance in opening direction the air inlet valve magnet 209 will be energized simultaneously with the energization of the closing relay 283 over a circuit including the auxiliary contacts 327 (Fig. 5) which close very early in the opening stroke before the contacts 277 close. This circuit extends from the line 285 through the recloser 321, conductor 325, contacts 327, conductor 329, the latch check contacts 284,

conductors

305 and 279, coil of the inlet valve magnet 209, contacts 333, conductor 275, back contacts 271 of the release relay 273 and conductor 269 to the supply line 267. In this manner the inlet valve magnet 209 is energized Without Waiting for the closing relay 283 to pick up or the auxiliary contacts 277 to close and closing air is admitted to the operating cylinder 17 very early in the opening stroke of a nontrip-free operation to quickly reverse the direction of movement of the circuit breaker and cause a quick, highspeed reclosure of the breaker contacts from a partially open position.

Upon admission of the closing charge of compressed air to the operating cylinder the contacts 333 are opened so that the inlet valve magnet Will be deenergized upon opening of the auxiliary contacts 277 which open early in the closing stroke, thus realizing early energization of the inlet valve magnet on the opening operation to effect quick reclosure and early cut oi of the air on the closing stroke to conserve air. As previously described, deenergization of the inlet valve magnet causes the valve 203 (Fig. 3) to close shutting oif the high pressure air from the area above the dump valve 215. At the same time the valve 211 opens dumping the high pressure air from these areas, permitting the inlet valve 173 to close and permitting the high pressure closing air in the operating cylinder 17 to blast the dump valve 215 open dumping the closing air charge from the operating cylinder. This effects closing of the contacts 333 substantially at the end of the closing stroke.

If the fault has been cleared from the circuit controlled by the breaker, the mechanism will be latched and remain in the closed position. However, if the breaker closes in against a fault on the line, the breaker Will be tripped open free of the closing mechanism by the tripfree latch since this tripping action will occur before the closing air charge is dumped and the selector bar 101 (Fig. l) is in the position to select the trip-free latch 75 (Figs. l, 2 and 5) for operation. Operation of the tripfree latch 75 causes opening of the latch check contacts 284 (Fig. 5). This opens the circuitsV for energizing the closing relay 283 and the inlet valve magnet 209 and '12 these cannot be energized until the mechanism is reset and relatched. By the time this occurs on the trip-free opening operation, the auxiliary contact 277 will be closed and the second reclosing operation will be initiated by the closure of the latch check contacts 284 which occurs When the trip-free latch isl restored to latching position. This insures that the mechanism is reconnected to the breaker before closing air is admitted to the operating cylinder to effect the second and subsequent reclosure of the breaker.

Figure 6 illustrates a modiiication of the invention wherein the early energization of the inlet valve magnet 209 during the non-trip-free opening operation is effected by additional, normally closed, back contacts on the closing relay 283. These contacts 345 (Fig. 6) are connected in the circuit in parallel relation to the auxiliary contacts 277 by

conductors

347 and 349 and serve the same purpose as the pneumatically operated contacts 333 shown in Figs. l and 5. The circuit for energizing the inlet valve magnet 209 over the contacts 345 extends from the recloser 321, conductor 325, auxiliary contacts 327 which close early in the non-trip-free opening operation, conductor 329, latch check contacts 284,

conductors

305 and 279, coil of the inlet valve magnet 209, conductor 349, contacts 345, conductor 347, contacts 271 of the release relay 273 and conductor 269 to the supply line 267. With the breaker closed when the trip magnet 91 is energized a very slight movement of the mechanism in opening direction closes auxiliary contacts 327 energizing the inlet valve magnet 209 very early in the opening stroke to quickly reverse the movement and close the breaker. The closing relay 283 is energized simultaneously with the inlet valve magnet opening the back contacts 345 and closing the contacts 281 to hold the inlet valve magnet energized. This transfers the control of the inlet valve magnet 209 from the contacts 345 to the auxiliary contacts 277 which open early in the closing stroke to deenergize the inlet valve magnet.

On a subsequent trip-free opening operation, when the breaker closes in against a fault, energization of the inlet valve magnet 209 and the closing relay 283 is controlled by the latch check switch contacts 284 which close when the mechanism is reset and relatched.

The invention provides novel means for eifecting early admission of the closing charge of compressed air to the operating cylinder of a compressed air operated circuit breaker during the opening stroke to eiect exceedingly high-speed reversal of the parts and quick reclosure of the breaker before the breaker reaches full open position, and also eiects early cut off of the compressed air to the operating cylinder during the closing stroke to conserve the consumption of compressed air per closing operation and obtain the maximum number of reclosures from a tank of compressed air.

Having described the invention in accordance with the provisions of the patent statutes, it is to be understood that various changes and modications may be made in the structural details thereof Without departing from the spirit of the invention.

We claim as our invention:

l. An automatic reclosing circuit breaker including a control circuit, operating means for said breaker power means for closing said breaker, electroresponsive means operable When energized to eiect energization of said power means, iirst auxiliary contacts connected in said circuit in series relation With said electroresponsive means and closed by said breaker operating means at a predetermined time during the opening operation of said breaker operating means, second auxiliary contacts connected in said circuit in series relation with said irst auxiliary contacts and closed by said breaker operating means during the opening operation of said breaker operating means before said rst auxiliary contacts close, said second auxiliary contacts being opened by said breaker during a closing operation of said breaker after 13 said first auxiliary contacts open, normally closed contact means connected in said circuit in parallel relation with said first auxiliary contacts to permit said second auxiliary contacts to effect energization of said electroresponsive means before said first auxiliary contacts close to thereby effect quick reversal of the moving parts of said breaker and quick reclosure of said breaker before said breaker reaches full open position, and means operative simultaneously with energization of said power means for opening said normally closed contact means upon the initiation of a closing operation to permit said first auxiliary contacts to effect deenergization of said electroresponsive means before said second auxiliary contacts open during the closing operation of said breaker.

2. An automatic reclosing circuit breaker including a control circuit, operating means for said breaker power means for closing said circuit breaker, electroresponsive means operable when energized to effect energization of said power means, first auxiliary contacts connected in said circuit in series relation with said electroresponsive means and closed by said operating means at a predetermined time during the opening stroke of said breaker operating means, second auxiliary contacts connected in said circuit in series relation with said first auxiliary contacts and closed by said operating means during the opening stroke of said breaker before said first auxiliary contacts close, said second auxiliary contacts being opened by said breaker during a closing operation of said breaker after said rst auxiliary contacts open, normally closed contact means connected in said circuit in series relation with said electroresponsive means and in parallel relation with said first auxiliary contacts, said normally closed contact means being responsive to the energized condition of said power means, said normally closed contact means being in the closed position in the deenergized condition of said power means to permit said second auxiliary contacts to effect energization of said electroresponsive means early in an opening operation to thereby effect quick reversal of said breaker and quick reclosure of the breaker before the breaker reaches full open position, and means operative when said power means is energized to open said normally closed contact means and permit said first auxiliary contacts to effect deenergization of said electroresponsive means before said second auxiliary contacts open during the closing stroke of said breaker.

3. An automatic reclosing circuit breaker including a control circuit, fluid pressure operating means for closing said breaker, electroresponsive means operable when energized to admit fluid pressure to said closing means to close said breaker, first auxiliary contacts connected in said circuit in series relation with said electroresponsive means and closed by said fluid pressure operating means at a predetermined time during the opening stroke of said breaker, second auxiliary contacts connected in said circuit in series relation with said first auxiliary contacts and closed by said circuit breaker operating means during the opening stroke of said breaker before said first auxiliary contacts close, said second auxiliary contacts being opened by said breaker during a closing operation of said breaker after said first auxiliary contacts open, fluid pressure responsive contact means operated by fluid pressure in said fluid pressure operating means and connected in said circuit in parallel relation with said first auxiliary contacts, said fluid pressure responsive contact means being normally closed to permit said second auxiliary contacts to effect energization of said electroresponsive means to thereby effect quick reversal of the moving parts and quick reclosure of said breaker before the breaker reaches full open position, and said normally closed fluid pressure responsive contact means being opened by fluid pressure when fluid pressure is admitted to said fluid pressure operating means to permit said first auxiliary contacts to effect deenergization of said electroresponsive means before Said second aux- 14 iliary contacts open during the closing stroke of said breaker.

4. An automatic reclosing circuit breaker including a control circuit, operating means for said breaker power means for closing said breaker, electroresponsive means operable when energized to effect energization of said power means, a closing relay having a coil connected in said control circuit, first normally open auxiliary contacts connected in said control circuit and closed by said breaker at a predetermined time during the opening operation of said breaker, second normally open auxiliary contacts connected in said control circuit in series relation with said first auxiliary contacts and closed by said breaker during the opening operation of said breaker before said first auxiliary contacts close, said second auxiliary contacts being opened by said breaker during a closing operation of said breaker after said first auxiliary contacts open, normally closed contacts operated by said closing relay and opened by energization of said closing relay coil, said normally closed contacts being connected in said control circuit in parallel relation with said first normally open auxiliary contacts to permit said second auxiliary contacts to effect energization of said relay coil and said electroresponsive means before said first normally open auxiliary contacts close during an opening operation of said breaker to thereby effect quick reversal of the moving parts of the circuit breaker and quick reclosure of said breaker, and said closing relay coil when energized opening said normally closed contacts to permit said first auxiliary contacts to effect deenergization of said electroresponsive means before said second auxiliary contacts open during the closing operation of said breaker.

5. An automatic reclosing circuit breaker including a control circuit, operating means for said breaker power means for closing said breaker, electroresponsive means operable when energized to effect energization of said power means, a closing relay having a coil connected in said control circuit, first normally open auxiliary contacts connected in said control circuit and closed by said breaker operating means at a predetermined time during the opening operation of said breaker, second normally open auxiliary contacts connected in said control circuit in series relation with said first auxiliary contacts and closed by said circuit breaker during the opening operation of said breaker before said first auxiliary contacts close, said second auxiliary contacts being opened by said breaker during a closing operation of said breaker after said first auxiliary contacts open, normally closed contacts operated by said closing relay and opened by energization of said closing relay coil, said normally closed contacts being connected in said control circuit in parallel relation with said first normally open auxiliary contacts to permit said second auxiliary contacts to effect simultaneous energization of said electroresponsive means and said closing relay coil before said first auxiliary contacts close during an opening operation of said breaker to thereby effect energization of said electroresponsive means and quick reversal of the moving parts of the circuit breaker and quick reclosure of said breaker, and said normally closed contacts being opened by energization of said closing relay coil to permit said rst auxiliary contacts to effect deenergization of said electroresponsive means before said second auxiliary contacts open during the closing operation of said breaker.

6. An automatic reclosing circuit breaker including a control circuit, operating mechanism for said breaker, power means for closing said breaker, trip-free tripping means and non-trip-free tripping means normally releasably restraining said operating mechanism in closed position and selectively operable to effect opening of said breaker, electroresponsive means operable when energized to effect energization of said power means, trip selector means operable in response to the energized 15 v c condition of said power means, said trip selector means when said power means is deenergized being positioned to select said non-trip-free tripping means and being moved to a position to select the trip-free tripping means by energization of said power means, first auxiliary contacts connected in said circuit in series relation with said electroresponsive means, said rst auxiliary contacts being closed by said breaker operating means at a predetermined time in the opening operation of said breaker operating means and opened by said breaker operating means at a predetermined time in the closing operation of said breaker operating means, second auxiliary contactstconnected in said circuit in series relation with said Viirstauxiliary contacts, said second auxiliary contacts being closed by said breaker operating means during said opening operation before said iirst auxiliary contacts and opened by said breaker operating means during said closing operation after said first auxiliary contacts, contact means connected in said circuit in parallel relation with said first auxiliary contacts and responsive to the position of said trip selector means, said contact means being closed by said trip selector Cil means when said trip selector means is in position to select said non-tripfree tripping means to permit said second auxiliary contacts to elect energization of said electroresponsive means before said rst auxiliary contacts close to thereby eiect quick reversal of the moving parts of said breaker and quick reclosure of said breaker before said breaker reaches full open position, and movement of said trip selector means to the position to select said trip-free tripping means causing opening of said contact means to permit said first auxiliary contacts to effect deenergization of said electroresponsive means before said second auxiliary contacts open during said closing operation.

References Cited in the file of this patent UNITED STATES PATENTS 2,408,199 Cumming et al. Sept. 24, 1946 2,479,315 Coggeshall Aug. 16, 1949 2,546,007 Leng'al et al. Mar. 20, 1951 2,619,523 Bonine et al. Nov. 25, 1952