US2548221A - Fluid pressure actuated switch - Google Patents

Description

April 10, 1951 A. c. KELLE FLUID PRESSURE ACTUATED SWITCH connected in series.

Patented Apr. 10, 1951 FLUID PRESSURE ACTUATED SWITCH Arthur C. Kelle, Stoughton, Mass., assignor to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., a corporation of Delaware Application February 15, 1949, Serial No. 76,556

7 Claims.

This invention relates in general to a pneumatic control system and particularly to an improved control system and parts thereof suitable for Operating a gas blast circuit breaker. As the currents to be interrupted by circuitbreakers of the gas blast type become increasingly greater and as it becomes desirable both to operate such circuit breakers in shorter times and to encase the circuit breakers in small metal housings, the slower operating systems and the conventional arrangement of elements in the prior art circuit breakers cannot meet the desired time and space requirements.

It is therefore an object of the present invention to provide a pneumatic operating system for a gas blast circuit breaker that will perform its cycle of opening and closing operations in a minimum of time.

It is also an object of the present invention to provide an arrangement of gas blast circuit breaker elements in a metal-clad housing such that only a small housing space is necessary, while maintaining adequate insulation distances and electrical safety provisions.

It is also an object of the present invention to provide a new and improved gas blast circuit breaker in which isolatin disconnect contacts are closed and maintained closed against the action of gravity and are opened in cooperation with the action of gravity.

Objects and advantages other than those above set forth will be apparent from the following description when read in connection with the accompanying drawing in which the single figure is a diagrammatic representation of a gas blast circuit breaker operating system embodyin the present invention.

In the drawing, an electric circuit (not shown) connected to conductors 30 and 3| is shown as controlled by a circuit breaker of the gas blast type. The conductors 30 and 3| extend through studs 9 to contact blocks 40 which have thereon fixed contacts 3 shown as bridged by a conducting movable main or bridging contact 4. The contacts 3, 4 are contacts of high current carrying capacity and are positioned where heat can easily be dissipated therefrom and are arranged in a magnetic loop such that current flow tends to hold the contacts closed.

In parallel with the bridging contacts 3, 4 are arcing contacts I, 8 and disconnect contacts 5, 6

Arcing contact 8 is in permanent conductive connection with conductor or terminal element 3 and arcing contact 1 is in permanent conductive connection with a fixed me- ZOO-81.4) V

2 tallic chamber defining means, such as structure 4|, which is arranged in spaced relationship to conductor or terminal element 30. Structure 4| substantially encloses arcing contacts 1 and 8 and is arranged parallel to terminal elements and 3|. The disconnecting switch, comprising disconnect contacts 5 and 6, is arranged substantially on one side of the axis of metal structure 4|. Movable disconnect contact 5 is in permanent conductive connection with structure 4| and is arranged transversely to the terminal elements 30 and 3| so as to extend across the space between structure M and terminal element 30. The connection of terminal element 3|, arcing contacts l and 8, disconnect contacts 5 and 6 and terminal element 30 in series defines a loopshaped current path.

A reservoir containin gas suitable for are extinguishing is shown at l0 and for purposes of illustration the gas therein will be considered to be air maintained under pressure of the order 01' and through an exhaust pipe [3 to atmosphere.

Separate means such as fluid motor 42, 5|, 52 and 53 are utilized to operate the arcing contacts, disconnect contacts, the bridging contacts and the blast valve, respectively. Motor 5| is provided with a piston 20 having rod 2| movable therewith and connected through linkage including a cam member 22 and a link 62 to the movable disconnect contact 5. Motor 52 has a piston [6 having a rod I! connected through linkage to the movable bridging member 4. The cam member [8, operably connected to the rod l1, cooperates with cam 22 to prevent opening of the disconnect contact 5 unless the bridging contact 4 is in open position. Also, a camming action of cam l8 closes the disconnect contact 5, if open, .upon

movement of the bridging contact 4 to closed position.

Thus, motors 5| and 52, through the movement of cams -|8and 22, cooperate to actuate engagement with the fixed disconnect contact 6 against the action of gravity. Cam 22 and link 62 act as an over center toggle in that respect. To separate the cooperating disconnect contacts, the movable disconnect contact 5 is actuated by motor 5| in cooperation with the action of gravity to a lower level away from the fixed or stationary disconnect contact 6; Motor 42 is arranged substantially coaxially with respect to structure 4|.

In the circuit breaker as shown in the drawing, the contacts are all shown in the closed position and current flow is. fromconductor through contacts 3, 4 to conductor 3|. of solenoid valve I4 initiates the opening operation of the circuit breaker. Air under pressure from tank II] is supplied through pipeI5, through the solenoid valve I4, through the pipe '16 to slide,

valve I2. With the slide valve I2 in the position shown, air passes through the slide valve, through pipe 84 to the chamber 68 ofthe fluid motor 52.

As pressure rises in chamber 68, valve 70 is operated admitting air to the underside of piston I6. Movement of piston I6 upward causes piston rod H to move the linkage to break toggle 85 to the left as viewed in the drawing, thereby opening bridging contact 4. This movement of rod I'I upward rotates the cam I8 in a counterclockwise direction and clears the path of movement of the cam- 22.

Upon movement of the piston I 5 upward a predetermined distance, slide valve I2, connected to movewith rod I1, closes ofi pipe 84 from supply pipe 16 and opens pipe I8 to pipe 46. With pipe 46 supplied with air under pressure, the blast valve motor 53 is operated. Air is supplied under piston 44 and, as outlet port 48 is covered by slide valve 49, the piston 44 is moved upward opening blast valve II. Movement of piston 44 at the top of the stroke is arrested and the shock absorbed by resilient material 98.

Opening of the blast valve I I admits air to manifold 45 and thereby to the arcing contact chamber 26 and to the cylinder containing arcing contact operating piston 42. Movement of the piston 42 upward opens the arcing contact 8, allowing the air to blast through orifice contact 'I. An auxiliary electrode 86 may be provided and connected to a resistance (not shown) which may be wound on thecooling chamber I2, which resistance is connected to contact block 40 by conductor 43. The are gases are cooled in the muffler I2 and exhausted through pipe I3 to atmosphere.

When air is suppliedv to the manifold by opening, of the main blast valve II, pressure air is supplied through pipe I8 to the chamber 58 of fluid motor 5|. In order to assure a. proper sequence of operation of arcing contact 8 and disconnecting, contact 5, a needle valve 18 in the line 18 is provided for adjustment ofv the air flow therein. As pressure builds up in chamber 58, thevalve 60 is opened admitting air under pressure to thebottom of piston 28. Movement of piston 20 and piston rod 2| upward rotates the cam member 22 in a clockwise direction about its pivot 81 opening the movable disconnect contact 5.

At a predetermined opening of the disconnect contact 5, links move a slide valve 59 to uncover an exhaust port 48 andopen an inlet port 41.. This releases pressure beneath piston and allows tank pressure to be applied on the top the piston, thus rapidly reclosing val'veII Upon.

closing of valve I I, pressure air is shut Qfi 10. 1

Operation chamber 26, permitting arcing contact 8 to reclose under bias of a spring (not shown). Rapid reclosing of blast valve II and arcing contact 8 is very necessary from the standpoints of time of circuit breaker reclosing and of air conservation.

Fluid motors 5|, 52 and 53 are designed to permit a fast reclosing of the circuit breaker. Motor 5I is. provided with a dumping valve 28 providing for release of pressure underneath piston 20 at or near the end of the upward stroke. An operating member 55 on rod 2I operates poppet valve 54 permitting pressure in the chamber 58 to leak off to atmosphere. The difference of pressures under the piston 28 and in chamber 58 forces the valve 28 downward against the pressure of its biasing spring, thereby opening the space underneath the piston 28 to atmosphere and immediately relieving the pressure therein.

In the motor 52 a similar action takes place, poppet valve 64 is operated by operating member 65 movablevvith the piston rod I'i. Operation of valve 64 lowers the pressure in chamber 68 therebyoperating dumping valve 88 to permit a rapid release of pressure under piston I5. Motors 5I and 52 are therefore ready for immediate reversal.

Due to the improved fluid motors and to the rapidinterruption of the circuit, the foregoing operation is completed in a few cycles. The circuit breaker is ready for reclosing which may be effected by energization of the solenoid valve I5. With solenoid valve I4 closed, pressure air from the pipe I5 is supplied through solenoid valve I5 and pipe 11 to chambers 59 and B9 of motors 51 and" 52. With downward movement of pistons 28 and I6 the bridging contacts 4, 3 and the disconnect contacts 5, 6 are reclosed, with the limitation provided by cams I8 and 22 that the bridging contacts 3, 4 must be reclosed subsequent to closure of disconnect contacts 5, 6. If movement' of contacts 3, 4 tends to be faster than movement of contacts 5, 6, movement of cam IS in a clockwise direction forces cam 22 to close contact 5. This prevents arcing at the bridging contacts 3, 4 and provides for closing of the circuit'at the disconnect contacts 5, 6 especially de-' signed for closing against heavy currents Upon movement of pistons 20 and I8 downward, operating members 57, and 6'! operate pop pet valves 56 and 65 to provide release of pres' sure above the pistons 28 and I6 in a manner similarto' the pressure release afforded by valves 54 and 64. Movement of piston rod I? downward moves slide valve I2 to the position shown in the drawing and the blast valve having been closed, the circuit breaker is immediately ready for a subsequent opening operation. Considerable saving in reclosing time is effected by the simultaneous energization of motors 5I and 52 for closing and by insuring of the proper closing sequence by the abutting cam members I8 and 22. The interlock afforded by cams I8 and 22 involves no loss of time.

In order to arrange the elements of a gas blast circuit breaker as shown, so that it may be encased in a metal housing as small or smaller than the housing now utilized for an oil circuit breaker of equivalent current rating, many problems were solved. It is generally desirable in avertical lift switchgear to have the studs 8 enter the housing through the top of the breaker so that they may connect to overhead circuit connections.

The circuit breaker is enclosed in a housin 36 and is movable horizontally on wheels into a cell. The entire circuit breaker and housin is in open position.

vision of stop 24 on the cell framework which stop cooperates with a link 23 connected to is moved vertically from the floor 3! to a position in which conductors 30 and 3! are connected to the circuit to be controlled. The

circuit breaker housing 36 shown at the left is these include the studs 9 and all of the contacts.

The front portion contains only elements that are either at ground potential or that present an outer surface of insulating material thus making the front of the circuit breaker electrically dead and therefore safer for the operator. The disconnecting contacts 5, B are so arranged that if upon a faulty operation an arc is drawn,

such are will be blown onto the adjacent grounded housing 36.

The circuit breaker cannot be moved into the cell far enough to be raised to circuit connected position shown unless the disconnect contact This is assured by prothe cam linkage 22, whereby movement of the circuit breaker to the left forces cam 22 to rotate in a clockwise direction opening the contact 5 providing bridging contact 4 is also open. If the contact 4 is not open, cam 18 prevents move ment of cam 22, and the breaker cannot be moved into the proper position for raising into the position shown. When the breaker is in the open position, the circuit breaker is then lifted to circuit connected position by a lifting means (not shown). When the circuit breaker is lifted to circuit connected position, member 23 may move into a slot 25, thereby permitting closing operation of the circuit breaker. A slot 35 in a locking member 34, operated by the circuit breaker lifting and lowering mechanism, prevents lowering of the circuit breaker unless in open position. A slot 33 permits link 89 to be in the slot 35 or on the top of member 34 if the slot 35 is not in alignment with link 89. The link 89 is lifted clear of member 34 if the disconnect is in open position.

Although the various elements of the circuit breaker system have been described as operating in conjunction with each other, the improvements disclosed have utility other than with all of the elements shown and described. For example, the fluid motors 5| and, 52 may be utilized for any purpose where quick reversal of a fluid motor is desirable. While the disclosed arrangement of bridging contacts 3, 4 is desirable for circuit breakers of high current rating, these contacts may be omitted in the lower current ratings.

The improvements utilized in effecting a quick reclosure of the blast valve ll, although shown as initiated by movement of the disconnect contact 5, may as well be effected by an isolating movement of the arcing contacts I, 8 in cases where no separate disconnect is utilized. The present disclosure of an interrupting operation utilizing an auxiliary electrode 86 and associated resistor is by way of illustration, for in the lower current ratings, these elements may be omitted.

For simplicity and clarity of disclosure, a single pole circuit breaker has been described and shown, although usually a multipole circuit breaker is operated. In such cases, the manifold 45 extends to the interrupting chambers of the additional poles, and the linkages operated by motors 5| and 52 operate shafts for additionally operating the disconnect and bridging contacts of the other poles.

Although a single embodiment has been illustrated and described, it willbe apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims. Features disclosed but not claimed herein are claimed in copending application Serial No. 545,929, filed July 21, 1944, and United States Patent No. 2,464,237, granted March 15, 1949, of Arthur C. Kelle.

It is claimed and desired to secure by Letters Patent:

1. In a fluid blast circuit breaker the combination of a first fixed terminal element, a second fixed terminal element, a stationary arcing contact, a cooperating movable arcing contact, means for establishing a blast of fluid under pressure adjacent said arcing contacts, a first fluid operated motor for separating said arcing contacts, means for permanently 'conductively connecting one of said arcing contacts with said first terminal element, a fixed metal structure in permanent conductive connection with the other of said arcing contacts and arranged in spaced relation with respect to said second terminal element, a disconnecting switch arranged in series relation with said arcing contacts and comprising a stationary disconnect contact and a cooperating movable disconnect contact, one of said disconnect contacts being in permanent conductive connection with said metal structure, and said movable disconnect contact normally extending across the space between said metal structure and said second terminal element, an actuating lever hinged to said movable disconnect contact, and a second fluid operated motor for operating said actuating lever for moving said movable disconnect contact to a lower level away from said stationary disconnect contact.

2. In a fluid blast circuit breaker the combination of a first fixed terminal element, a second fixed terminal element, a stationary arcing contact, a cooperating movable arcing contact, means for establishing a blast of fluid under pressure adjacent said arcing contacts, a first fluid opminal element, a fixed metal structure in permanent conductive connection with the other of .said arcing contacts and arranged in spaced relation with respect to said second terminal element, a disconnect switch arranged in series relation with said arcing contacts and comprising a stationary disconnect contact and a cooperating movable disconnect contact hingedly supported by said metal structure and normally extending across the space between said metal structure and said second terminal element, and a second fluid operated motor for moving said movable disconnect contact to a lower level away from said stationary disconnect contact.

3. In a fluid blast circuit breaker the combination of a first terminal stud, a second terminal stud arranged parallel to said first stud, a pair of relatively movable arcing contacts, a fluid operated motor of the reciprocatory type for separating said pair of arcing contacts, means for permanently conductively connecting one of said 7 arcing contacts with said first stud, metallic means defining a chamber in permanent conductive connection with the other of said arcing contacts and enclosing said arcing contacts, said chamber defining means being arranged in spaced relation with respect to said second stud and substantially coaxially with respect to said motor, a disconnecting switch arranged in series relation with said arcing contacts and operative upon separation thereof, said disconnecting switch being arranged substantially on one side of the common axis of said motor and chamber defining means and comprising a movable disconnect contact normally extending across the space between said chamber defining means and said second stud, said first stud, said arcing contacts, said disconnecting switch and said second stud defining a loop-shaped current path, a tank for storing fluid under pressure arranged outside of said loop-shaped current path on the side of said common axis of said motor and chamber .defining means opposite said disconnecting switch, and means for establishing an arc extinguishing blast of fluid under pressure from said tank adjacent said arcing contacts.

4. In a fluid blast circuit breaker the combination of a first terminal stud, a second terminal stud arranged parallel to said first stud, a pair of relatively movable arcing contacts, a fluid operated motor of the reciprocatory type for separating said arcing contacts, means for permanently conductively connecting one of said arcing contacts with said first stud, metallic means defining a chamber in permanent conductive connection with the other of said arcing contacts and enclosing said arcing contacts, said chamber defining means being arranged in spaced relation with respect to said second stud and substantially coaxially with respect to said motor and parallel to the axes of said studs, a disconnecting switch arranged in series relation with said arcing contacts and operative upon separation thereof, said disconnecting switch being arranged substantially on one side of the common axis of said motor and chamber defining means and comprising a, movable disconnect contact normally extending across the space between said chamber defining means and said second stud, said first stud, said arcing contacts, said disconnecting switch and said second stud defining a loop-shaped current'path, a tank for storing fluid under pressure arranged outside of said loop-shaped current path on the side of said common axis of said motor and chamber defining means opposite said disconnecting switch, and means for establishing an are extinguishing blast of fluid under pressure from said tank adjacent said arcing contacts.

5. In a fluid blast circuit breaker the combination of a pair of spaced parallel terminal studs, a pair of cooperating arcing contacts, a contact separating fluid operated motor of the reciprocatory type comprising a cylinder arranged substantially coaxially with respect to, and supported by, one of said studs, a, chamber for enclosing said pair of contacts and arranged substantially coaxially with respect to said one of said pair of studs and supported by the cylinder of said mo- Ill) tor, means for establishing a blast of fluid under pressure through said chamber in a direction generally away from, and longitudinally of, said one of said. studs, and a disconnecting switch in series relation with said arcing contacts and operative upon separation thereof, said disconnecting switch comprising a hingedly supported contact normally arranged in acute angular relation to said studs and connecting one of said arcing contacts with the other of said studs.

6. In an electric switching device and combination of a fixed arcing contact and a cooperating movable arcing contact in series with a fixed disconnect contact and a cooperating movable disconnect contact, a lever means attached to said movable disconnect contact at a point intermediate the ends thereof, a first reciprocatory motor means actuated by fluid under pressure for actuating said movable arcing contact, and a second reciprocatory motor means actuated by fluid under pressure for actuating said lever means to move said movable disconnect contact in contact closing direction against the'action of gravity and maintain the movable disconnect contact in engagement with said fixed disconnect contact against the action of gravity and for moving said movable contact in cooperation with the action of gravity for separating said disconnect contacts.

7. In a fluid blast circuit breaker the combination of a first fixed vertically mounted terminal element, a second fixed vertically mounted terminal element, a stationary arcing contact, a cooperating movable arcing contact, means for establishing a blast of fluid under pressure adjacent said arcing contacts, a first fluid operated motor for separating said arcing contacts, means for permanently conductively connecting one of said arcing contacts with said first terminal element, a fixed metal structure in permanent conductive connection with the other of said arcing contacts and arranged in spaced relation with respect to said second terminal element, a disconnecting switch arranged in series relation with said arcing contacts and comprising a stationary disconnect contact and a cooperating movable disconnect contact, said stationary disconnect contact being mounted at the lower end of said second terminal element and said movable disconnect contact being pivotally connected to said metal structure, said movable disconnect contact normally. extending across the space between said metal structure and said second terminal element, and a second fluid operated motor connected with said movable disconnect contact for pivoting said movable disconnect contact downward to separate said disconnect contacts.

ARTHUR C. KELLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,282,153 Baker et a1 May 5, 1942 2,363,283 Baker et a1 Nov. 21, 1944 2,364,254 'Thommen et al Dec. 5, 1944

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