US2558757A - Multibreak gas blast circuit breaker with grounded operating motor - Google Patents

Description

July 3, 1951 G. E. JANSSON MULTIBREAK GAS BLAST CIRCUIT BREAKER WITH GROUNDED OPERATING MOTOR 3 Sheets-Sheet 1 Filed July 19, 1947 "I'll INVENTOR AA/JXQW (a. Qa/wa/qo/w A ORNEY July 3, 1951 G. E. JANSSON MULTIBREAK GAS BLAST CIRCUIT BREAKER WITH GROUNDED OPERATING MOTOR 3 Sheets-Sheet Filed July 19, 1947 &(

IPIVENTOR g waXow ZQDW/J/OAA/ We RNEY July 3, 1951 G. E. JANSSON MULTIBREAK GAS BLAST CIRCUIT BREAKER WITH GROUNDED OPERATING MOTOR .3 Sheets-Sheet 5 Filed July 19, 1947 0 I I I I I I I I I I a I lNYENTOR Q W W 5. W, W

E N R Patented July 3, 1951 MULTIBREAK GAS BLAST CIRCUIT BREAKER WITH GROUNDED OPER- ATING MOTOR Gustav E. J ansson, North Quincy, Mass., assignor to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., a corporation of Delaware Application July. 19, 1547, Serial No. 762,092

12 Claims. 1

My invention relates to electric circuit breakers of the gas or fluid blast type adaptable for very high voltage ratings, particularly to air blast circuit breakers, and it has for its principal object the provision of improved multibreak structure for efiecting synchronous operation of the contacts at all breaks pertaining to one pole of the circuit breaker or one phase of the circuit.

Another object of my present invention is to provide an improved gas blast circuit breaker comprising a plurality of pairs of cooperating arcing contacts arranged in electrical and spatial series relation in one pole unit of the circuit breaker structure and means for compelling, at a point of tim at which a predetermined minimum amount of gas pressure prevails at all points of break, simultaneous positive-action separation of all cooperating pairs of arcing contacts.

Another object of my present invention is to provide a gas blast circuit breaker of the type comprising a plurality of pairs of cooperating arcing contacts arranged in electrical and spatial series relation in one pole unit of the circuit breaker structure, wherein all said pairs of con-'- tacts may be separated simultaneously independently of the gas pressure at diiferent points of break, and irrespective of whether there is a difference in gas pressure at diiierent points of break.

Another object of the present invention is to provide a gas blast circuit breaker of the type comprising a vertical hollow insulating column accommodating therein a plurality of superimposed pairs of cooperating arcing contacts arranged in electrical series relation and which includes motor means arranged at ground potential and adapted to separate simultaneously said plurality of pairs of contacts, and Which includes, in addition thereto, time delay means for causing operation of said motor means after a time delay following the opening of the blast valve of the circuit breaker sufiicient to permit substantial equalization of the pressure at all points of break.

Another object of my present invention is to provide a gas blast circuit breaker pole unit including one movable arcing contact, or a plurality of movable arcing contacts arranged in electrical series relation, which contact is or contacts are adapted to be operated through the intermediary of rotating insulating structure by means of a single motor arranged at ground potential remote from said contact or contacts.

Another object of the present invention is to provide an improved circuit breaker structure of the gas blast type which lends itself to the interruption of circuits having a very high operatingvoltage, is simple, reliable in operation and relatively inexpensive to manufacture.

Objects and advantages other than those described above will be apparent from the following description when read in connection with the accompanying drawing, in which:

Fig. l is a pressure vs. time characteristic for a fluid passage having a given geometric-a1 con figuration;

Fig. 2 is a diagrammatical view, partly in cross section and partly in side elevation, of a gas blast multibreak circuit breaker of the outdoor type embodying the features of the present invention;

Fig. 3 is a view, partly in cross section and partly in side elevation, of the circuit breaker column and operating mechanism of Fig. 2, shown on a larger scale;

Fig. 4 is a cross section taken along line IV-IV of Fig. 3, seen in the direction of the arrows indicated in Fig. 3;

Fig. 5 is a cross section taken along line VV of Fig. 3, seen in the direction of the arrows indicated in Fig. 3;

Fig. 6 is a front view, partly in cross section and partly in side elevation, of a modification of the contact operating mechanism of Fig. 3;

Fig. 7 is a cross section taken along line VII VII of Fig. 6, seen in the direction of the arrows indicated in Fig. 6; and

Fig. 8 is a diagrammatic View, partly in cross section and partly in side elevation, of an operating mechanism intended to be used in combination with the circuit breaker structure of Figs. 2 and 3 for the purpose of rapid reclosing service.

A multibreak gas blast circuit breaker comprises means defining a blast passage having at one end thereof a blast valve for the admission therein of gas under pressure. A plurality of breaks is arranged within the passage at difierent points along the axis thereof. Since it takes time for the past blast or pressure Wave to develop and to rush or travel through the blast passage,

shortly upon opening of the blast valve the pres-' sure within the blast passage will diiTer depending both upon the particular point of time under consideration as well as upon the location of any particular point under consideration along the axis of the blast passage. Owing to these facts there will be a tendency in a multibr-eak gas blast circuit breaker that opening of cooperating pairs of fluid pressure operated contacts occurs at different points of time, depending on how far such pairs of contacts are arranged away from the blast-admitting valve, In addition thereto, there will be a tendency that the intensity of the arc extinguishing blast will vary depending upon the location within the blast passage of a particular pair of cooperating contacts, and upon the point of time at which the particular pair of contacts under consideration is permitted to part. Fig. 1 shows the pressure vs. time characteristic for the end of an 11 ft. long pipe line having restricted outlet and intake areas, the fixed ratio of which is (outlet closed), and .445, respectively (outlet open). It appears from Fig. 1 that the pressure wave rises gradually with time to a peak value and then decreases in form of a relatively slightly damped oscillation if the outlet is closed, and in the form of a very strongly damped almost aperiodic oscillation in case the outlet is open.

The foregoing shows that it is of great importance to provide gas blast multibreak circuit breakers with means which permit to synchronize the operation of all the contacts and which, in addition thereto, permit proper timing between the opening of the blast valve, the transit of a given pressure Wave and the separation of the contacts so as to permit building-up of the right amount of gas pressure within the blast passage at any point thereof where a pair of cooperating contacts is located.

This problem has been solved by the structure which is shown in Figs. 2 and 3, and which will now be described in detail.

Breaker tank I constitutes a source of fluid, e. g., air, under pressure for producing arc extinguishing blasts of gas as well as for operating the contacts of the circuit breaker. Pipe 2 supplies gas under pressure to tank I either from another larger tank or from a compressor, of which neither are shown in the drawing. Blast valve 30. controls the escape of gas under pressure into blast passage 3. The circuit breaker comprises further a plurality of pairs of cooperating arcing contacts 4, arranged in electrical and spatial series relation or registry within blast passage 3. Contacts 4 are stationary and tubular, or of the nozzle type, and contacts 5 are movable and of the plug type, normally closing the ori- M fices formed by the nozzle type contacts. Upon separation of each pair of cooperating contacts 4, 5 an arc extinguishing blast of gas under pressure is caused to rush through the gaps which are formed therebetween. These blasts of gas have been indicated by arrows in Figs. 2 and 3. The structure which causes these blasts of gas to form will be described below more in detail. Separation of cooperating pairs of contacts 4, 5 is effected by a fluid motor generally indicated by the reference sign 6, a crank mechanism l, a rotatable insulating column generally indicated by the reference sign 8, two crank mechanisms 9, both associated with column 8, and contact operating linkages including the reciprocable operating rods III. Gas under pressure is applied to motor 6 comprising relatively movable cylinder I2 and piston I3 from blast passage 3 through pipe H which branches off blast passage 3 at a point situated downstream with regard to blast valve 30.. Upon a predetermined movement of piston I 3 in cylinder I2 in contact opening direction, port I4 is freed by piston I3, thus permitting pipe I5 to be supplied with gas under pressure. Gas under pressure flowing through pipe I5 causes a fluid motor which has been generally indicated by reference sign IE to open a disconnect switch which has been generally indicated by reference sign I1. Fluid motor I6 comprises relatively movable piston I8 and cylinder I9 and a slide valve 20. The flow of gas under pressure supplied through pipe I5 causes both piston I8 and slide valve 20 to move from right to left. The movement of slide valve 20 to the left causes opening of port area 2I, thus permitting venting of the left side of cylinder I9 to atmosphere. Disconnect switch I! comprises the stationary contact 22 and the movable or rotatable contact 23. The latter is adapted to be actuated by motor I6 through crank mechanism 24, rotary insulating column 25 and bevel gear 26. The circuit through the circuit breaker when in closed position is as follows: line 21, terminal 28, arcing contacts 4, 5, flexible conductor 29, arcing contacts :5, 4, 4, 5, flexible conductor 29, arcing contacts 5, 4, terminal 33, disconnect contact 23, disconnect contact 22, terminal 3|, line 32. Motor I6 for operating disconnect switch I! is associated with auxiliary switch 33 which is being closed upon a predetermined travel of piston I8 in contact opening direction. Closing of switch 33 causes closing of a control circuit which includes conductor 34 and solenoid contact resetting valve 35. When valve 35 opens, gas under pressure is permitted to flow from tank I through pipe 36 to motor 6. This causes piston I3 and slide valve 38 to move from left to right, resulting in closing of cooperating pairs of arcing contacts 4, 5 and venting of the right side of cylinder I2 through port 39. The contact closing action of motor 6 is speeded up by the action of spring 40 which exerts the required contact pressure when the circuit is closed by the arcing contacts 4, 5 of the circuit breaker. In the contemplated case the circuit will not be closed upon resetting of arcing contacts 4, 5 since it is interrupted by reason of separation of disconnect contacts 22, 23.

Operation of the circuit breaker is initiated by energizing solenoid trip valve 4|. This permits a flow of gas under pressure from tank I through pipe line 43 to pilot valve 44, causing the latter to open. Opening of pilot valve 44 permits gas under pressure to flow from tank I in back of piston 45 of a fluid motor 46 for operating blast Valve 3a. Motor 46 comprises also cylinder 41 and spring 48 arranged therein for reclosing blast valve 3a and maintaining it in closed position. Upon opening of blast valve 3a cooperating pairs of arcing contacts 4, 5 are opened by motor 6, whereupon disconnect switch I! is opened by motor I6, and finally contacts 4, 5 are reclosed by the combined action of motor 5 and spring 40, as described above.

Closing of the circuit breaker is initiated by energizing solenoid valve 49, thus causing gas under pressure to flow from tank I through pipes 43 and 43a to motor I5. That flow of gas under pressure causes piston I8 and slide valve 20 to move from left to right. This in turn causes contacts 22, 23 to engage and port area 50 to be opened to atmosphere for venting the right side of cylinder I3.

Referring now particularly to Fig. 3, it will be seen from that figure that the blast passage 3 is in part defined by a hollow supporting insulator 5i and also by a plurality of hollow insulating elements .53 which are arranged in registry and are superimposed upon insulator 5I. What may be termed the circuit breaker column proper which has generally been designated by reference sign 205, comprises said hollow insulating elements or tubular insulators 53 and a plurality of metal casings 52. Insulators 53 are arranged coaxially on opposite sides of metal casings 52 and form spatial extensions of chambers defined by casings 52. Each insulator 53 houses a pair of cooperating arcing contacts 4, 5 and is provided with a substantially cylindrical element 54. Elements 54 define guiding surfaces 55 for insuring movement of contacts 5 in a straight, preferably a vertical line. Elements 54 are each provided with a flange 56 clamped between one of the casings 52 and one of the insulators 53. This clamping feature holds element 54 firmly in position, thus insuring proper alinement of all the stationary and movable contacts 4, 5. Flanges 55 are provided with apertures 51 (shown in dotted lines in Fig. 3 and more clearlyin Fig. 7) for permitting gas under pressure to flow in an upward direction through insulators 53 and metal casings 52 up to the top of the column 250. The stationary contacts 4 are provided with flanges forming part of venting structures which are more fully described below. The flanges which are associated with contacts 4 provide a clamping feature of the same kind as flanges 56 of elements 54.

- Operation of contacts 5 is effected by pushpull or reciprocating operating mechanisms, i. e., mechanisms adapted for positive fluid-pressure action actuation of contacts 5 in alternative directions. Each metal casing 52 houses one pushpull operating mechanism generally indicated by the reference numeral 58. Each push-pull operating mechanism 58 is adapted to convert operating impulses in a direction transversal of passage 3 and tubular insulators 53 into a pair of opposite forces in a direction longitudinal of said passage and insulators. There are many possible operating mechanisms capable of converting transversal operating impulses of operating rods Iii into a pair of opposite operating impulses in a direction longitudinal of circuit breaker column 255, and Fig. 3 shows merely one possible, though a preferred, push-pull operating structure of that kind. Each of the contacts 5 is adapted to be operated by a crank or toggle mechanism comprising the elements 59 and 50. Each pair of elements 59 is rotatable about a common shaft 5| arranged in a direction transversal of the breaker column 259 and supported by one of the metal casings 52. The metal casings 52 are each provided with a slide bearing 62 for supporting operating rods l5. Rods II] are each connected to a pair of elements 59 by means of a toggle comprising two links 63. Each metal casing 52 has two wide flanges 54 for securing the tubular insulators 53 to it. This is achieved by means of angle members 65, wedge members 63 and screws 51.

The mechanisms 59, 60 described above form toggle joints for transmitting the reciprocatory force produced by the movement of operating rods sin a direction substantially in alignment with the axis of contacts 4 and 5. Elements 50 and interconnected elements 59 actuate movable contacts 5 upon movement of operating rods in and substantially reduce the side thrust which would be exerted by operating rods II] on movable contacts 5 if only toggles 63 were connected therebetween.

As clearly shown in Fig. 4, the apertures 51 in flange 55 are arranged in such a way as to cause the vertical flow of gas under pressure through casing 52 to bypass the pushpull operating mechanism 58 which is arranged in that casing, thus minimizing frictional losses within said flow of gas under pressure. The lower metal casing 52 is constructed in the same way as the upper metal casing 52.

The end of each insulator 53 arranged remote from the respective casing 52 to which the insulator is secured is provided with means permitting the escape of are products or fluid under pressure from tubular contacts 4 to atmosphere. These venting means comprise metal structures generally indicated by reference numeral 20l defining passages 75 for the escape of are products in a substantially horizontal direction. Cooling structures-252 arranged in passages 10 effect a reduction of the temperature of the escaping are products prior to their escape. The cooling structures 202 consist preferably of stacks of parallel plates of a metal having a high heat absorbing capacity, e. g., copper, and they are arranged in the direction of the flow of arc products so as to minimize frictional flow losses. The venting structure 28! arranged in the middle of the breaker column 200 comprises a partition plate H which may be of insulating material and separates the are products issuing from immediately adjacent nozzle contacts 4 prior to their cooling and release to atmosphere.

As shown in Fig. 5, the venting structure 205 which is arranged in the middle of the breaker column 250 comprises partitions l2 defining two ducts 13 which permit a direct flow of gas under pressure from the insulator 53 immediately below partition H to the insulator 53 immediately above partition H, thus bypassing venting passages Hi. The venting structure Zill on the bottom of the breaker column 200 is constructed in a similar way, i. e., it permits air under pressure issuing from tubular insulator 5| to flow directly into the lowermost insulator 53, thus bypassing the exhaust passages 16 situated at the bottom end of the breaker column 251]. The venting structure 25! on top of column 205 permits escape of all the air under pressure which reaches the top of said column, i. e., it has no bypass means as the two venting structures which are arranged at a lower level.

Gas under pressure entering the lowermost insulator 53 may, in part, escape through the gap formed between the lowermost contacts 4, 5 upon separation thereof, and in part rush through apertures 51 in flanges 56 and the lower metal casing 52 into the next higher insulator 53. Here again the flow of gas under pressure is divided into two branch flows, one escaping through the gap formed between contacts 4, 5 upon separation thereof and through the venting passage Ii! of the venting structure 25f situated at the middle of column 200, and the other flowing through bypass ducts 13 (see Fig. 5) to the insulator 53 situated immediately above the middle of the breaker column 200. Here the flow of gas under pressure undergoes another subdivision into two branch flows. One branch flow follows the path through the gap formed between the separated contacts 4, 5 and the upper of the venting passages 10 of structure ZBI situated at the middle of column 258. The other branch flow follows the path through apertures 51 in flanges 56 and through casing 52 into the uppermost insulator 53, and then through the gap formed between the uppermost contacts 4, 5 upon separation thereof and through the venting passages 5 situated on the top of the circuit breaker column 280 to atmosphere.

The vertical rotary insulating column 8 is mad up of two parts 8a and 8b. The lower part 8?) is adapted to be rotated by fluid motor 6 which essays-v 7. is arranged at g'roundpotenti'al, or substantially at ground potential. The lower crank mechanism 9 for actuation of one of the operating rods I is arranged between the parts 8a, 8b of rotary insulator 8'1 Shaft i l interconnects parts are and 8b of insulator hand that shaft is supported by abearing which in turn is supported by a rigid cross-tie it, which is secured to the lower of the two casings E2. The shaft H on top of part 812; of rotatable insulator 8 is supported by a'be'aring it which in turn is supported by arigid cross-tie l9 which is secured to the upper of the two casings 52.- It will be noted that both crossties l6 and 79 are substantially horizontal and situated at about the same level as metal casings 52, or shafts 5 l, respectively.

The flexible conductors 29' which have been shownin Fig. 2 have been omitted in Fig. 3, for clearness sake, but it is to be understood that eachpair of movable contacts 5 which is associated with one push-pull operating mechanism 58 is electrically interconnected. Since all arcing contacts i, 5 of the circuit breaker are supposed to be serially connected when the breaker is in the closed position thereof, it is necessary to provide means for electrically interconnecting the two tubular contacts 4 which are arranged close to the middle of the breaker column 200. This interconnection is effected by the metallic cooling structure (see particularly Fig. 5) and a shunt conductor may be added, if desired, for electrically interconnecting said contacts 4.

It will be noted that the interval of time or time delay between initiation by opening of blast valve ca of building up of pressure within the circuit breaker column 200 and simultaneous parting of all pairs of contacts 4, 5 depends upon the operation of fluid motor 6. The point of time at which motor 6 begins to operate'depends' in turn upon the cross section of pipe II and can be varied, if desired, by arranging a needle valve therein (no such valve has been indicated in the drawing).

Since nozzle and plug contacts 4, 5'a're separated and gas under pressure is permitted to escape from column 20G only subsequent to the opening of blast valve 3a, column 290 will be substantially closed at the point of time when blast valve'3a is being opened. Hence a damped pressure wave of the character shown in Fig. 1 will occur within column 200 immediately upon opening of blast valve 3a. Contacts 4, 5 are separated at a suitable point of time when the pressure conditions prevailing in breaker column 209 at the various points of break are most favorable for efiicient circuit interruption.

In the closed position of contacts 4', 5 the angle between contact operating elements 59 and 60 is close tol80 degrees. Shifting of operating rods !9 from the right to the left, as viewed in Fig. 3, results in rapid reduction of the pressure between contacts 4, 5' to zero and separation of said contacts.

Figs. 2 and 3 show one pole-unit for controlling one phase of an electric circuit. In the case of multiphase circuits, a plurality of such pole-units may be associated for controlling all the phases of the circuit. Storage tank I and the blast valve 311 may be common to all pole units of a composite multiphase circuit breaker. This common tank and blast valve feature is less appropriate for relatively large multiphase circuit breaker arrangements; the pole units of relatively large multiphase circuit breaker arrangements should preferably each have a 8. separate breaker tank and aseparate blast valve.

It will be understood that the contact structure and operating means shown in Figs.- 2 and 3 are not limited to multibreak circuit breakers but canalso beused to advantage in circuit breakers having but one point of break. I-n gas" blast circuit breakers of the multibreak type there is a relatively long distance between the blast valve and the arcingcontacts which are arranged most remotely therefrom, and, there'- fore, the possibility of proper timing of the separation of cooperating pairs of contacts is of paramount importance in the case of multibr'eak gas blast circuit breakers. Besides, the problem of synchronizing the operation of the contacts of one pole-unit is peculiar to multibreak circuit breakers.

The circuit breaker of the present invention comprises, as has been shown before, a plurality of identical basic structures as, for instance, cas-f ings 52, insulators53, operating mechanisms 58. The number of these basic structuralelements can be decreased or increased depending upon the required voltage rating and-interrupting capacity rating,- i. e., different circuit breakers to suit different requirements can be assembled from the samebasic elements.

The reactions of the accelerating forces to which contact-s 3, 5 are subjected are of opposite direction; the forces acting upon bearings 15 and 18 tend to move said bearings to the left, while the forces which are transmitted by shafts 6| upon metal casings 52 tend to move said casings to the right, as viewed in Fig. 3. These forces are substantially balanced by the provision of the crcss ties it and 790i which each interconnects one of the bearings lii'and 18 with one of the two m'c-ta'l casings 52, and which are arranged at about the same level as shafts 6i. Cross-ties 16 and 79 will be subjected to tensile stresses, but all accelerating forces or their reactions, respectively, are substantially kept away from the insulating elements 53 of which column 200 is made up, which elements are generally of ceramic material, and,- therefore, not well adapted to withstand mechanical impact forces.

Another desirablefeature of the circuit'breaker of the present invention consists in that contacts 4, 5 can bereclo'sed against full-gas pressure in the interrupting chambers formed by" insulators 53, which is evidently due to the fact that the operation of fluid motor ii does not depend upon the pressure within column 20b. The gear ratio of the operating mechanism 8, 9, l0 and 58 is such that extremely high contact pressures can be exerted with relatively small forces being present at the motor end'of said'mechanism.

Referring now to Figs. 6 and 7, metal casing 52' is situated between a pair of coaxially arranged insulators 53. Insulators'53'rest upon the wide flanges of casing'EZ andare secured to them by means including members 65 and 66. Each insulator 53 houses a stationary nozzle contact 4, a movable plug contact 5 and a member 54- defining guiding surfaces for telescoping contacts along a straight line, i. e., the direction of the axis of passage 3. Casing 52 is provided with two bearings iii and 82 for supporting shaft 83. Shaft 83 carries crank element 84. Crank elements'85 interconnect each of the movable contacts 5" With one of the ends of crankelement 84. Shaft 83 carries an arm 86 arranged exteriorly of metal casing 52 for rotating shaft 83 to contact open position or in the opposite direction, 1. e.,

to contact closed position. Arm 86 may be operated by any suitable motor arranged remote from casing 52 and at ground potential by the intermediary of a suitable insulating element. Preferably arm 86 is being attached by means of a linkage including a universal joint to a motor-operated vertical insulating column of the kind of column 3 shown in Figs. 2 and 3.

The push- pull operating mechanism 83, 84, 85, 86 of Figs. 6 and '7 is less involved than that of Fig. 3, and it does not require a slide bearing as the latter does, which features make it more desirable in some respect.

Referring now to Fig. 8, that figure shows a modification of the operating means for the rotary contact-operating insulating column 8 and a modification of columnB itself, the other parts of the circuit breaker having been omitted, or indicated in a diagrammatic Way. Column 8 comprises two superimposed coaxial parts 3a, 8b, which are interconnected by an eccentric element I09. Element I is associated with an element IOI and adapted to operate a reciprocating rod II Both elements I60 and IIII form a crank mechanism. Rod I8 forms part of a push-pull operating mechanism (not shown in detail) adapted to convert a horizontal operating impulse into a pair of vertical impulses of opposite directions for efiecting relative movement of contacts 4 and 5. The crank mechanism formed by elements we and I OI permits column 8 to rotate about 360 degrees (without reversing its sense of rotation). Column 8 is supported by shaft I02 resting in two bearings I83. Toothed or spur wheels lll la and IBM) are loosely mounted on shaft I82. Toothed racks Iii5a, IEiEb are in cooperative engagement with spur wheels IMa and 16%, respectively. Fluid motor IBBa comprising piston IG'Ia, cylinder IUBa and resetting spring Ififia is adapted to operate rack I05a. Fluid motor 15% comprising piston ifllb, cylinder I98!) and resetting spring IIiSb is adapted to operate rack Iilfib. Fluid under pressure may be supplied to motor IIi'ia through solenoid trip valve III), and cylinder Iota of motor [06a may be vented by means of venting valve III. Orifice II2a is arranged about midway between the ends of cylinder H3811 and adapted to permit cylinder I882) to be supplied with gas under pressure through pipe line IIZ. Pipe line H2 is controlled by the solenoid reclosing lock-out relay II3. Ratchet gear Ii is fixedly mounted on shaft I 02 of column 8 and adapted to be operated either by a ratchet IIiia hinged to spur wheel IBM, or by a ratchet H51), hinged to spur wheel I941). Racks Ififia, IE-Eb, are provided with push rods I lea and i I617, respectively. Push rod H50. controls an interlock limit switch II? arranged in the energizing circuit of solenoid trip valve Iii], while push rod H61) controls venting Valve II-I of cylinder HlSa.

Alternatively cylinder I 682) of fluid motor I052), may be supplied with gas under pressure through pipe I i8 and check valve I IS. The rate of escape of gas under pressure from cylinder I 08?) may be controlled by adjusting needle valve I29.

The control system shown in Fig. 8 operates as follows: Occurrence of a fault as, for instance, an arcing ground connection, causes energization of solenoid trip valve He and hence admission of gas under pressure to fluid motor 36a. Piston I Illa moving from right to left moves rack I05c from right to left. The latter causes rotation of spur wheel 59442 which, in turn, causes a rotation of ratchet wheel H4, shaft IE2 and insulating column 8 of approximately 180 degrees, resulting in separation of contacts 4, 5. Rapid reclosing is efiected by gas under pressure flowing through port 21; and pipe H2 in back of piston Illlb of fluid motor IIlSb. This causes piston ID'Ib and rack I052) to move from left to right and ratchet gear IM to be rotated through ratchet II 51) in the same sense as before, thus causing an addi tional degrees rotation of shaft I02 and column 8 in the same sense as before. Owing to this additional 180 degrees rotation contacts 4, 5 are rapidly reclosed upon separation thereof. Movement of push rod II6b to the right causes opening of venting valve I II which enables rapid resetting of motor Iilfia owing to the action of spring Essa. Auxiliary switch II? which had been opened by push rod IIBa is allowed to reclose upon r setting of motor I 06a, thus permitting rc-energization of solenoid trip valve I I 9. If the duty cycle of the circuit breaker comprises but one immediate reclcsing operation, pipe H2 is blocked upon the first reclosing operation by solenoid lockout valve H3 and this causes column 8 to travel merely to contact open position rather than to move farther to contact closed position.

If contacts 4, 5 are separated as a result of an interrupting operation other than a rapid reclosing duty cycle, contacts 3, 5 are reclosed by admitting gas under pressure to motor IBBb through pipe I I8 and check valve I It, thus causing piston Hill) to move from left to right. Owing to the action of needle valve I20 motor I081) resets itself upon a given period of time. This causes a rotation of spur gear IMb Without, however, affecting ratchet gear I I4 and column 8.

Although but several embodiments of the present invention have been illustrated and described, it will be 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.

It is claimed and desired to secure by Letters Patent:

1. In a circuit breaker, the combination of a member at least in part of insulating material defining a, passage, a pair of cooperating contacts within said passage, a supply of gas under pressure, means connecting said passage and said supply for producing blast of gas having a slightly damped pressure wave through said passage, a contact separating means operated independently of the gas pressure in said passage, and means for synchronizing said contact separatin means with said blast producing means to separate said contacts when a crest of said pressure wave reaches said contacts.

2. In a, circuit breaker, the combination of a member at least in part of insulating material defining a passage, a plurality of serially connected pairs of cooperating contacts within said passage, a supply of gas under pressure, means connecting said passage and said supply for producing a blast of gas having a slightly damped pressure wave through said passage, and a contact separating means operated independently of the gas pressure in said passage for simultaneous separation of all of said pairs of contacts at a time at which said pressure wave reaches the point of break most remote from said source.

3. In a circuit breaker, the combination of a member at least in part of insulating material defining a passage, a plurality of serially connected pairs of cooperating contacts within said passage, a supply of gas under pressure, means connecting said passage and said supply for producing a blast of gas having a slightl damped pressure wave through. said passage, and a contact separating means operated independently of the gas pressure in said passage for simultaneous actuation of all of said pairs of contacts at a time at which a crest of said pressure wave reaches the point of break most remote from said source and irrespective of whether there is a difference in gas pressure at different points of break.

4. In a circuit breaker, the combination of a member at least in part of insulating material defining a passage, a pair of cooperating contacts within said passage, a supply of gas under pressure, means connecting said passage and said supply for producing a blast of gas under pressure havinng a slightly damped pressure wave through said passage, a contact separating means operating independently of the gas pressure in said passage and comprising an insulating column adapted to be rotated about the longitudinal axis thereof arranged generally parallel to said passage, a transmission interconnecting said column and one of said contacts adapted toconvert rotary motions of said column into lineal motions of said one of said contacts in a direction longitudinal of said passage, and a motor for rotating said column, said motor being actuated at a time at which said pressure Wave reaches said contacts.

5. In a, circuit breaker, the combination of a metal casing, a tubular insulator arranged vertically on and carried by said casing, supply of gas under pressure, means connecting said casing and said supply for producing a blast of gas under pressure having a slightly damped pressure wave through said casing and said insulator comprising blast entrance means at the end of said insulator adjacent said casing and blast exhaust means at the end of said insulator remote from said casing, a pair of cooperating contacts arranged in the path of said blast, contact separating means operated independently of the gas pressure in said casing and comprising a motor actuated upon a predetermined travel of said pressure wave, an insulating column rctatable about the vertical axis thereof and adapted to be rotated by said motor, and a transmission adapted to convert rotary motions into lineal motions, said transmission interconnecting said column and one of said contacts.

6. In a circuit breaker, the combination of a member at least in part of insulating material defining a passage, a pair of cooperating arcing contacts mounted within said passage for es tablishing an arc, a supply of gas under pressure, a conduit connecting said passage and said supply for producing a blast of gas having a given pressure wave through said conduit and said passage, a contact separating means operating independently of the gas pressure in said passage and comprising a fluid motor having a pipe connection to said conduit, and means for adjusting th flow of gas through said connection to cause said motor to separate said contacts a predetermined time after the transit of said pressure wave through said conduit past said connection.

'7. In a circuit breaker, the combination of a member at least in part of insulating material de-- fining a passage, a pair of cooperating arcing contacts mounted within said passage for establishing an are, a supply of gas under pressure, a conduit connecting said passage and said supply for producing a blast of gas having a given pressure;

wave through said passage, and. a contact separating means operating independently of the gas pressure in said passage and comprising a fluid motor arranged at substantially ground potential, said motor having a pipe connection to said conduit whereby said motor is actuated a predetermined period of time after the transit of said pressure wave through said conduit past said connection, an insulating column adapted to be rotated about its axis by said motor, and a transmission interconnecting said column and one of said contacts and adapted to convert rotary motion of said column into lineal motion of one of. said contacts.

8-. In a circuit breaker, the combination of a metal casing, a tubular insulator immediately adjacent said casing and communicating therewith, a pair of cooperating arcing contacts mounted Within said insulator for establishing an arc, a supply of gas under pressure, a conduit connecting said casing and said supply for producing ablast of gas'having a given pressure wave through the gap'formed between said contacts upon separation thereof, blast exhaust and cooling means at the end of said insulator remote from said casing, and a reciprocatory contact separating means operating independently of the gas pressure in said casing comprising a fluid motor arranged at substantially ground potential, said motor having a pipe connection to said conduit whereby said motor is actuated a predetermined period of time after the transit of said pressure wave through said conduit past said connection, an insulating column adapted to be rotated by said motor about an axis generally parallel tosaid insulator, and a transmission interconnecting said column and one of said contacts and adapted to convert rotary motion of said column. into lineal motion of one of said contacts.

9. In combination, a circuit breaker comprising a plurality of superimposed elements forming a vertical hollow column, said elements including a pair of spaced metal elements each arranged between insulating elements, a plurality of pairs of separable cooperating contacts each associated with one of said insulating elements, means for serially connecting said plurality of pairs of contacts, a supply of gas under pressure, a conduit connecting said hollow column and said supply for producing a blast of gas having a given pressure wave through said hollow column, common means Within each metal element for separating pairs of cooperating contacts associated with the insulating elements immediately adjacent thereto, a pair of crank mechanisms exteriorly of said metal elements and insulating elements each operatively associated with one of said common means, and actuating means operating independently of the gas pressure in said hollow column and comprising a "first vertical rotary column for insulatingly interconnecting said pair of crank mechanisms, a second vertical rotary column for insulatingly supporting said first rotary column, and a fluid motor arranged at substantially ground potential and actuated in a predetermined relation to the transit of said pressure wave through said hollow column for operating said second rotary column.

10. In a circuit breaker, the combination of a metal casing forming a chamber, a pair of insulators arranged coaxially on opposite sides of said casing and defining tubular extensions of said chamber, a pair of stationary contacts each associated with one of said insulators, a pair of movable contacts each adapted to cooperate with one of said stationary contacts, guiding means within each of said insulators for telescoping said movable contacts in the direction of the common axis of said insulators, each said guiding means having a supporting flange clamped between said casing and one of said insulators, means for producing blasts of gas under pressure having a predetermined pressure wave through the gaps formed between cooperating contacts upon separation thereof, gas exhaust means on the ends of said insulators remote from said casing, a reciprocatory operating mechanism having a stroke parallel to the axis of said insulators for common simultaneous actuation of said movable contacts in opposite directions, and means for actuating said mechanism including an operator of insulating material and a motor arranged at substantially ground potential for actuating said operator, said motor being adapted to effect synchronized separation of said contacts a predetermined time after said pressure wave reaches said contacts.

11. In a circuit breaker, the combination of a metal casing, a tubular insulator arranged vertically on said casing and communicating therewith, means for producing a blast of gas having a predetermined pressure wave through said insulator, blast exhaust means on the end of said insulator remote from said casing, a pair of cooperating contacts arranged in the path of said blast of gas, an insulating column rotatable about the vertical axis thereof, a transmission for converting rotary motions of said column into vertical lineal motions of one of said contacts, and a pair of sequentially operating fluid motors of the cylinder-piston type adapted to rotate said column sequentially in the same direction about angles of substantially 180 degrees, said first operating motor actuated independently of the gas pressure in said insulator'and at a predetermined time after said pressure wave reaches said contacts.

12. In a circuit breaker, the combination of a metal casing, a pair of tubular insulators arranged coaxially at opposite sides of said casing and communicating therewith, means for producing a pair of opposite blasts of gas under pressure each through one of said insulators, gas exhaust means on the ends of said insulators remote from said casing, two pairs of cooperating contacts each arranged in the path of one of said blasts of gas, an insulating column rotatable about the vertical axis thereof, a transmission for converting rotary motions of said column into lineal opposite motions of one contact of one of said pairs of contacts and of one contact of the other said pair of contacts, a shaft for supporting said column, a pair of gears supported on said shaft for rotation independently thereof, a pair of racks each in cooperative engagement with one of said gears, a pair of fiuid motors of the cylinder-piston type adapted for alternate operation of said racks, and a ratchet mechanism connecting said gears to said shaft to cause said shaft to be rotated in response to rotation of either of said gears in a common predetermined direction.

GUSTAV E. J ANSSON.

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

UNITED STATES PATENTS Number Name Date 1,920,894 Ruppel Aug. 1, 1933 2,125,525 Thommen Aug. 2, 1938 2,205,321 Thieme June 18, 1940 2,279,536 Thommen Apr. 14, 1942 2,327,493 Bresson Aug. 24, 1943 2,394,046 Dickinson Feb. 5, 1946 2,454,586 Amer Nov. 23, 1948 2,456,965 Leitzel Dec. 21, 1948

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