US2568008A

US2568008A - High-voltage air blast circuit breaker having the blast valve arranged at line potential

Info

Publication number: US2568008A
Application number: US28666A
Authority: US
Inventors: Gustav E Jansson
Original assignee: Allis Chalmers Corp
Current assignee: Allis Chalmers Corp
Priority date: 1948-05-22
Filing date: 1948-05-22
Publication date: 1951-09-18
Anticipated expiration: 1968-09-18

Description

Sept. 18, 1951 JANssoN 2,568,008

G. HIGH-VOLTAGE AIR iLAST CIRCUIT BREAKER HAVING THE BLAST VALVE ARRANGED AT LINE POTENTIAL Filed lay 22, 1948 4 SheetSfSheet l ATTORNEY Sept. 18, 1951 G. E. JANssoN HIGH-VOLTAGE AIR BLAST CIRCUIT BREAKER HAVING THE BLAST VALVE ARRANGED AT LINE POTENTIAL 4 Sheets-SheefI 2 Filed llay 22, 1948 u M, 3 0N 6 o m H n .n 3 6 f M H ////v// P. 6 M

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Sept, 18, 1951 G. E. JANssoN HIGH-VOLTAGE AIR BLAST CIRCUIT BREAKER HAVING THE BLAST VALVE ARRANGED AT LINE POTENTIAL Filed lay 22, 1948 ////////////////////////aan m 6 u a w Sept 18, 1951 G. E. JANssoN 2,568,008

HIGH-VOLTAGE AIR BLAST CIRCUIT BREAKER HAVING THE BLAST VALVE ARRANGED AT LINE POTENTIAL Filed lay 22, 1948 4 Sheets-Sheet 4 Patented Sept. 18, 1951 HIGH-VOLTAGE AIR BLAST CIRCUIT BREAKER HAVING THE BLAST VALVE ARRANGED AT LINE POTENTIAL Gustav E. Jansson, North Quincy, Mass., assignor to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., a corporation of Delaware Application May 22, 1948, Serial No. 28,666

19 Claims.

This invention relates in general to circuit breakers, and more particularly to the operating means for the circuit breaker contacts and for a valve controlling the production of a gas blast for extinguishing the arc.

In circuit breakers of the gas blast type gas under pressure is generally stored in a reservoir or tank which is arranged substantially at ground potential, and the arc extinguishing blast of gas under pressure is conducted through an insulating blast passage from said reservoir or tank adjacent to the point of separation of the arcing contacts. In order to achieve high speed operation and high interrupting capacity, it is desirable to provide gas blast circuit breakers with means which permit minimizing the interval f time required for the arc extinguishing blast passing through the blast valve to reach the arc gap as well as with means which permit minimizing the difference between static tank pressure and blast pressure. High speed operation calls also for timing of the sequence of blast initiation and arc initiation with a high degree of accuracy. It is, therefore, one object of the present invention to provide a circuit breaker which permits minimizing both the interval of time required for the arc extinguishing blast to reach the arc gap as well as the difference between static tank pressure and blast pressure and which, in addition thereto, permits timing of the sequence of blast initiation and arc initiation with a high degree of accuracy.

Another object of the invention is to provide a circuit breaker of the gas blast type having the blast valve arranged at the downstream end of the insulating -blast passage and having means for correlating with a high degree of accuracy the time of opening of the blast valve and the time of opening of the contacts.

Y Still another object of the invention is to provide a circuit breaker of the axial gas blast type suitable for outdoor service and having a common control or operating means for both the movable contact and the blast valve that is simple and rugged and capable to withstand any punishment resulting from severe atmospheric conditions.

Further objects and advantages will readily become apparent upon reading of the following specification taken in conjunction with the drawings, in which:

Fig. l is a diagrammatic side elevation, partly in cross section, of an air blast circuit breaker of the axial blast type designed for outdoor service, and of aA pneumatic mechanism for operating that circuit breaker;

Fig. 2 is a perspective view of a pair of cams and push rods forming part of the circuit breaker structure shown in Fig. 1;

Fig. 3 shows in side elevation, and partly in cross section. a modiiication of the structure shown in Fig. 1, the arcing contacts being shown in their closed position;

Fig. 4 is a representation of the same structure as that shown in Fig. 3 with the arcing contacts shown in their open rather than their closed position;

Fig. 5 shows in side elevation, partly in cross section, -another embodiment of the present invention;

Fig. 6 is a cross section taken along the line VI--VI of Fig. 5;

Fig. 7 shows partly in side elevation and partly in cross section still another modication of the present invention;

Figs. 8 and 9 are horizontal sections taken along lines VIII-VIII and IX-IX, respectively, of Fig. 7, to show more clearly the shape of the cam means forming part of the structure of Fig. '7, said cam means being shown in Figs. 8 and 9 in contact closed position;

Figs. 10 and 11 are likewise horizontal sections taken along lines VIII-VIII and IX-IX, respectively, of Fig. 7, but showing said cam means in contact open position;

Fig. 12 is a vertical section along line XII-XII of Fig. 7;

Fig. 13 shows in front elevation and partially in cross section, on a larger scale, a detail of the structure of Fig. 7;

Fig. 14 is a horizontal section taken along line XIV-XIV of Fig. 13;

Fig. l5 is a side elevation, partly in cross section, of an axial type air blast circuit breaker involving the principles of the present invention;

Fig. 16 is a horizontal section along line XVI- XVI of Fig. 15; and

Fig. 17 is a vertical section along line XVII-- XVII of Fig. 15.

Referring now to Figs. 1 and 2 of the drawing, the circuit breaker comprises the circuit breaker AShaft 23 is journaled in been designated genand the operating structure which has been designated generally by reference sign 2. Air under pressure stored in tank 3 may be used for producing an arc extinguishing blast through the gap formed between arcing contacts 4 and 5 upon separation thereof as well as for actuating the operating structure 2. The passage 6 for supplying the arc gap formed between contacts 4 and 5 with air under pressure is in'part defined by blast tube 1 and in part dened by a hollow supporting insulator 8. Insulator 6 supports a casting 9 which defines an extension of passage 6 and forms the seat I for movable valve element Valve element |I is adapted to be operated by stem |2 and is, normally biased to the closed position thereof by helical spring I3. Casting 9 accommodates a toggle mechanism which has been indicated generally by reference character I4.

Toggle mechanism I4 is adapted to be operated by push rod I5, and when that rod is moved from left to right, as seen in Fig. 1, toggle mechanism I4 is caused to collapse and contact 5 is caused to separate from contact 4. Helical spring I6 arranged in a cylinder I1 formed by a portion of casting 9 acts through piston I9 upon toggle mechanism I4 and biases movable contact 5 to closed contact position. Casting 9 supports an insulator I9 `which, in turn, supports stationary nozzle contact 4.r 'I'he top of insulator I9 .is provided with a hood structure '20 defining exhaust passage a for the products of arcing.

Stem I2 and push rod I5 are each provided with a roller |2a and i5c, respectively. Roller I2a is adapted to engage a cam 2| and roller |5a is adapted to engage a cam 22. Roller I2a is carried by stem I2 by means of an intermediate lever 63 pivotally supported by stem I2 by means of pin 64. Lever 63 has a nose-shaped abutment 66, and is acted upon by biasing spring 65 tending yto rotate lever 63 about pivot pin 64 so as vto cause stem I2 to be engaged by abutment 66. Cams 2| and '22 are supported by shaft 23 which, in turn, is supported by insulator 24. bearings and 26 on

arms

21 and 28 which form integral parts of casting 9. Insulator 24 is supported by a shaft 29 journaled' in bearing 30 and adapted to be rotated by a fluid motor which has generally been indicated by reference sign 3 I.

Fluid motor 3| comprises a cylinder 32, a piston 33 movably arranged in said cylinder, a piston rod 34 attached to said piston, and a slide valve 35 operatively connected to said piston rod. Motor 3| is adapted to be supplied with air under pressure from tank 3 through a solenoid trip valve 36 and pipe 31. The left side of cylinder 32 is adapted to be supplied with air under pressure from tank 3 through closing solenoid valve 38, pipe 39, a passage defined by a portion of the housing of a lockout valve which has been indicated generally at 40, and pipe 4 I.

The straight line motion of piston 33 of fluid motor 3| is converted into a rotary motion of shaft 29, insulator 24 and shaft 23 by means of a crank mechanism 42.

Pipes

45 and 46 interconnect cylinder 32 of iluid motor 3| with the cylinder 43 of a` second fluid motor which has been indicated generally by reference character 44.

Pipes

45 and 46 are both controlled by a common slide element 41 of lockout valve 40. Said slide element 41 is biased by helical spring 48 to the right position thereof and can be actuated toward the left by -a third uid motor indicated generally at 50 and comprising a cylinder 5| and a piston 52. Cylinder 5| of fluid motor 56 can be supplied with air under pressure from tube 31 through branch tube 31a.

Piston 53 in cylinder 43 of uid motor 44 actuates a rotatable shaft 54 by means of piston rod 55 and crank mechanism 56. Piston rod 55 controls slide valve 51 for venting cylinder 43. Shaft 54 operates 'a rotatable insulator 58 which actuates bevel gear 59 for operating movable contact 60 of a disconnect switch indicated generally at 6|. Movable contact 60 of disconnect switch 6| is adapted to cooperate with stationary contact 62 for closing the circuit,

Fluid motor 2| is provided with a pair of ad- .justable needle valves 69 permitting to bleed fluid under pressure from cylinder 32. In a similar way and for the same purpose, cylinder 43 of fluid motor 44 is provided with a. pair of needle valves 10.

The operation of the arrangement shown in Figs. 1 and 2 is as follows: Upon energizing of solenoid valve 36, air under pressure rushing through pipe 31 moves piston 33 from the right to the left. This causes shaft 23 to be rotated through crank mechanism 42, shaft 29 and insulator 24. Rotation of shaft 23 effects sequential opening of blast valve IIJ, and separation of contacts 4, 5 by means of cam 2| and stem I2 and cam 22 and push rod I5. This sequence of operation is positively predetermined by the shape of cams 2| and 22. Since blast valve I0, il is situated at the downstream end of blast passage 6 immediately adjacent to contacts 4, 5, the time required for the blast to reach 'the gap formed between the separated contacts 4, 5 is minimized or, in other words, the speed of operation of the breaker is increased.

The ilow of air under pressure through pipe 31 and branch pipe 31a causes piston 52 of motor 50 to move from right to left, and this causes slide valve element 41 to block tube 46 and to open tube 45. Upon a predetermined travel of piston 33 of iiuid motor 3| to the left, air under pressure is allowed to flow from cylinder 32 of uid motor 3| through pipe 45 to cylinder 43 of fluid motor 44. This causes movement of piston 53 of iiuid motor 44 from left to rightre sulting in clockwise actuation of contact 60 of disconnect switch 6| through piston rod 55, crank mechanism 56, shaft 54, insulator 56 and bevel gear 59.- Sequential opening of arcing contacts 4, 5 and disconnect contacts 60, 62, is effected by reason of the fact that admission of iluid under pressure to fluid motor 44 for operating the latter is controlled by the uid motor 3| for operating the former.

Slide valves 35 and 51 permit venting of

cylinders

32 and 43 of fluid motors 3| and ,44, respectively, prior to the end of the respective opening strokes of said iluld motors. As

pistons

33 and 53 of fluid motors 3| and 44 approach their respective open contact positions, slide valves 35 and 51 close the ports at the far ends thereof. Consequently, air cushions are formed on one side of pistons 33 and 153 which decelerate the moving elements that are associated with said pistons and operate as shock absorbers. These air cushions are controlled by

adjustable needle valves

69 and 10, respectively, which per- 'mit complete bleeding oi of 'the cushion air upon completion of the opening strokes of fluid motors 3| and 44, respectively. When the disconnect contacts 60, 62 have parted a safe distance, precluding any restriking across thev air gap formed therebetween, blast valve element II is reset by the action of biasing spring I3 as a result of the particular shape of cam 2|. Cam 22, however, compels contacts 4, 5 to remain in the open position thereof until closing solenoid valve 38 is energized.

To close the circuit breaker, closing solenoid valve 38 is energized. This permits air under pressure to flow through pipe 39 to the left end of lockout valve 40, resulting in a movement of valve element 41 from left to right. Air under pressure flowing through pipes 39 and 4I then causes piston 33 of fluid motor 3| to move from left to right. Consequently, piston rod 34, crank mechanism 42, shaft 29, insulating column 24, shaft 23, cam 22, roller |5a, push rod I5 and toggle mechanism I4 move contact 5 into engagement with contact 4. Blast valve I0, II

is not opened during the closing stroke of fluid motor 3| on account of the resilient pivotal connection between valve stem I2 and roller carrying lever 63.

By reason of the movement of the valve element 41 from left to right, pipe 45 is blocked and pipe 46 is opened. Upon a predetermined travel of piston 33 of fluid motor 3|, air under 4pressure flowing through pipes 39 and 4I and cylinder 32 is admitted through pipe 46 to cylinder 43 of fluid motor 44. This particular feature causes, during the circuit closing process, a sequential operation of fluid motors 3| and 44. The movement of piston 53 of uid motor 44 from right to left causes piston rod 55, crank mechanism 56, shaft 54, insulator 58 and bevel gear 59 to move the movable contact 60 of disconnect switch 6I to the closed position thereof, thus completing the circuit closing operation.

During the initial stage of the circuit closing operation, slide valves 35 and 51 permit effective venting of the sides of

cylinders

32 and 43 toward which

pistons

33 and 53 are being moved. Said slide valves, however, close the ports at the nearends thereof during the final stage of the circuit closing operation, thus causing formation of decelerating, shock absorbing air cushions at the sides of

cylinders

32 and 43 toward which

pistons

33 and 53 travel. These air cushions are gradually bled off through needle valves 69, 1li. Upon closing of contacts 4 and 5 the required contact pressure is maintained by spring I6 in housing I1.

It is necessary that an opening operation should always take precedence over, or predominate over, a closing operation. In other words, opening should always be effected in response to a tripping impulse, irrespective of whether or not the closing solenoid valve is energized at the time. Assuming a closing impulse is given while a fault prevails, the opening 'impulse resulting from the fault condition should predominate over the closing impulse, even though the closing impulse is maintained continually.

Lockout valve 40 serves this particular purpose. When tripping solenoid valve 36 is energized, piston 52 moves slide element 41 from right to left, thus preventing fluid motors 3| and u from being supplied with closing air. If solenoid valves 36 and 38 are energized simultaneously, opening takes precedence because the effective fluid pressure reactive area of piston 52 is considerably larger than the effective fluid pressure reactive area of the left end of slide element 41. In other words, in the event of conflicting operating or control impulses the 6 opening impulse will always predominate, a larger effective fluid pressure reactive area being associated with said impulse.

The same reference characters having been applied to like parts in all the figures, no detailed description of the arrangement of Figs. 3 and 4 is required inasmuch as it is in substance the same as that shown. in Figs. 1 and 2. As shown in Figs. 3 and 4, rod I5'is hingedly supported by links 1I and 12 which are pivoted at 13 and 14, respectively. Shaft 14 is adapted to operate a toggle I4 which, in turn, is adapted to operate contact 5. Piston I8 which is acted upon by helical spring I6 arranged within cylinder I 1 is provided with a piston rod |8a connected to rod |5 by means of link 15. Rod I5 is adapted to be operated by cam 22 engaging roller I5a on rod I5. When cam 22 is rotated by shaft 23, rod I5 changes slightly its level since both its points of support move along circular paths, but cam 22 is so designed that a point of its surface is always in engagement with roller I5a.

Rotation of insulating column 24 in one direction causes sequential opening of blast valve I0, II, separation of contacts 4y 5, and reclosing of blast valve IIJ, II. Rotation of insulating column 24 in the opposite direction 'causes reengagement of contacts 4, 5 without, however, affecting blast valve I0, II. When column 24 is rotated in contact closing direction, rbller carrying arm 63 pivots about pin 64, thus; precluding opening of blast valve I0, I I.

The structure shown in Figs. 3 and 4 is supposed to be associated with an operating mechanism and a disconnect switch capable of performing substantially the same functions as the operating mechanism and the disconnect switch shown in Fig. l. The operating mechanism and disconnect switch have been omitted in Figs. 3 and 4 for simplifying these figures.

Referring now to Figs. 5 and 6, tubular insulator 8 4defines blast passage 6 and supports casting 9 forming a housing for a blast valve which has been generally indicated by reference character.16. Blast valve 16 comprises movable valve element II which is acted upon by helical biasing spring I3 tending to press valve element II against valve seat I0. Normally, air under pressure acts upon both the right and left end surfaces of valve element II. The effective area. of the right fluid pressure reactive surface of valve element I I is smaller than the effective area of the left pressure reactive surface thereof. However, the air pressure tending to move valve element II from its normal position shown in Fig. 5 to the right is much less than the sum of the air pressure and the pressure of spring I3 both tending to press valve element I I to the left against valve seat I0.

The space situated at the right side of valve element II is adapted to be vented by means of pipe 11, auxiliary valve chamber 18 and an orice |35 controlled by valve element 19.` Valve element 19 is adapted to be operated by means of stem resting in slide bearings 8|. Stem 80, in turn, is adapted to be operated by a crank mechanism which has generally been indicated at 82. Crank mechanism 82 is associated with an operating shaft 23 adapted to be operated by insulating column 24. The right end of stem 8l is surrounded by a helical biasing spring I|3 of which one end rests on a collar 80a on stem 88, while the opposite end rests against valve housing 18.

Upon rotation of shaft 23 in clockwise direction (as seen in Fig. 9) stem 80 moves to the right against the action of biasing spring l|3 and moves valve element 19 from the left valve seat I8 to the right valve seat 84 of valve housing 18. Consequently, pipe 85 interconnecting blast passage 8 with valve housing 18 is blocked and valve housing 18 vented to atmosphere. This causes the pressure on valve element directed from left to right to exceed that directed from right to left, resulting in rapid opening of blast valve 18. The blast of air under pressure which is admitted from blast passage 6 to the gap formed between separated contacts 4, 5 tends to extinguish the arc which is initiated upon parting of movable contact 5 from stationary'contact 4.

Separation oi contacts 4 and 5 is effected by an arm 86 of crank mechanism 82. Arm 98extends into a U-shaped abutment member 81 forming an integral part of rod I5 for actuating a contact operating toggle mechanism which has generally been indicated at |4. That toggle mechanism comprises link 89 adapted to operate links 89 and 90, of which the former is adapted to operate two links 9| and 92. Links 89 and 90 are joined together at 93 and link 90 is fulcrumed at 94, in casting 9. Links 89 Aand 9| are joined together at 95, and link 9| is fulcrurned at 98, in casting 9. Links 9| and 92 are joined together at 91, and link 92 is pivotally connected at 99 to movable contact 5. Arm 86 and U-shaped abutment member 91 form a lost motion connection between shaft 23 and link 98 which is responsible for a small time delay between opening of blast valve 16 and separation of contacts 4 and 5.

When crank mechanism 82 is rotated in clockwise direction (as seen in Fig. 6), arm 86 moves a predetermined distance before acting upon rod i5; then it engages the left abutment surface of member 81 moving rod |5 from right to left. Rod |5 acts upon piston i9 which, in turn, acts upon spring I8 in spring housing |1.A Spring I9 provides the necessary contact pressure in the closed position of the breaker and is compressed by the action of arm 96 during the circuit interrupting operation. When link 88 is actuated by rod |5 to the left, toggle 89, 90 collapses. This causes rotation of link 9|- about pivot 90 in a clockwise direction (as seen in Fig. 5), resulting in downward pulling of the movable contact which has been generally indicated at 5.

Movable contact 5 comprises a radially inner portion 99 and a radially outer portion |00. The radially outer portion is telescopically arranged in a cylindrical guiding member l0 i. The radially inner portion 99 is, in turn, telescopically arranged in the radially outer portion |00. Spring |02 which is arranged between portions 99 and |00 biases the former in upward direction. As clearly shown in Fig. 5, there is a certain axial play or lost motion between portions 99 and |00 and these two portions are provided with cooperating abutments 99a and |00a, respectively, which limit relative movement of portions 99 and |00 when the latter is disengaged from tubular stationary contact 4. i

Guiding member |0| is providedwith spring biased contact segments |02 for reducing the contact resistance between that member and radially outer portion |00. In a similar way, radially outer portion '|00 is provided with contact segments |03 for reducing the contact resistance between that portion and the radially inner portion 99. The radially inner portion 99 serves as arcing contact while the radially outer portion III serves as current carrying contact. When the radially outer portion is actuated in a downward direction by toggle mechanism |4, the radially outer portion |00 separates first from stationary nozzle contact 4. Upon a predetermined downward travel of portion |00 abutment |00a thereof engages the fianges or abutment 99a of portion 99, thus compelling the latter to separate from nozzle contact 4.

In order to causeireclosing of the blast valve 18 at thel end of the circuit interrupting operation, an intermediate link l |0 is arrangedbetween arms 96 and 86a of crank mechanism 82, and arm 86a is provided with an abutment member adapted to be engaged by a stationary abutment |2, Abutments and ||2 cause buckling of the toggle formed by members 89a, ||0 at the end of the circuit opening operation. This, in turn, permits spring ||3 to move stem 80 to the left, thus moving valve element 19 from right valve seat 84 to left valve seat 93. Consequently. compressed air is being admitted to blast valve 16 through passagesI 85 and 11, resulting in closing of blast valve 16, thus precluding continued consumption of compressed air upon interruption of the circuit and interposition of a suflicient amount of circuit insulation.

The structure shown in Figs. 5 and 6 is supposed to be associated with an operating mechanism and a disconnect switch capable of performing substantially the same functions as the operating mechanism and disconnect switch shown in Fig. l. Upon rotation of insulating co1- umn 24 in a clockwise direction (as seen in Fig. 6) crank mechanism 82 moves stem 90 from left to right, thus causing closing of pipe 85 by valve element 19 and venting of valve housing 18. Consequently, blast valve element moves from left to right, thus admitting a blast of air under pressure adjacent the contacts 4, 99 of the circuit breaker. lContact separation is effected shortly upon blast initiation by arm 86 engaging abutment member 81 and moving the same from right to left. When abutment member hits upon abutment member |2 and toggle 96a, I0 buckles, spring ||3 is free to move valve element 19 from right to left. This stops continued venting of blast valve 16 and reclosing thereof on account of the admission to it of air under pressure through pipes 95 and 11, as stated above. Reclosing of the contacts is effected by causing rotation of insulating column 24 in a counterclocli'.-n wise direction (as seen in Fig. 6)

Referring now to Figs. 7 to 14, a blast valve generally designated by reference 16 and comprising housing 9 and movable valve element is arranged coaxially with respect to hollow insulator 8 defining blast passage 6. Such a coaxial arrangement of a blast valve and a blast passage makes it possible to obtain an almost straight blast path from the tank (not shown) for storing air under pressure to the gap formed between the separated contacts Where arc extinction is to take place. In the structure shown in Fig. '7 the blast valve, the contact operating toggle mechanism and the contact arrangement itself are of the same general type as in the structure shown in Fig. 5 and the same reference characters are applied to designate like parts. In view thereof there is no need for a detailed description of the blast valve, the contact operating toggle mechanism and the contact arrangement shown in Fig. 7. Casting 9 forms also a housing 19 for an auxiliary valve including movable valve element 19. That auxiliary valve comprises a 75 valve seat 83 on its left side and a valve seat 84 on its right side. 'Valve element 19 is carried by stem 80 and restsenormally against left valve seat 03. In that position of valve element 19, blast passage 6 communicates with the spaces on both the axially upper and lower sides of valve element Air under pressure from the tank (not shown) passes through blast passage 6, a passage |90, about valve element Il, a valve seat 84, and a passage |94 to the lower side of valve element The fluid pressure exerted on the lower iiuid pressure reactive surface of valve element plus the force of helical spring i3 acting in the same direction exceeds by far the fluid pressure exerted on the upper fluid pressure reactive surface of valve element tending to move the same in a downward direction against the action of spring I3. Moving of valve element 19 from left to right results in venting to atmosphere of the space adjacent the lower uid pressure reactive surface of valve element I I. Now the pressure upon the upper fluid pressure reactive surface of valve element II exceeds by far the force of spring I3. The latter, therefore, is compressed and an arc extinguishing blast is allowed to fiow through blast valve 16 straight toward the arcing zone which is situated above it.

The mechanism for causing sequential opening of the blast valve and of the contacts and thereafter reclosing of the blast valve is operated by the rotatable insulating column 24 adapted to rotate control shaft H6. Control shaft ||6 is passed at right angles through cutout portions of members I|9 and |29, which portions are bounded laterally by curved surfaces I I1 and IIB in the nature of cam surfaces. Members I I9 and |29 are each arranged in one of a pair of tubular extensions |2| and |22, of casting 9. Control shaft I'I6 is adapted to operate members I I9 and |29 by means of arms |23 and |24, respectively. Arm |23 is adapted to engage cam surface ||1 of cam members |I9 and arm |24 is adapted to engage cam surface ||8 of cam member |29. To this end and in order to minimize friction between relatively movable cooperating parts, arms |23 and |24 are provided, at the radially outer ends thereof, each with a roller |25 and |26, respectively. Arm |23 is keyed to control shaft I|6 and arm |24 is loosely mounted upon said shaft and adapted to be rotated by said shaft through the intermediary of a ratchet mechanism. rIhat mechanism has been generally designated in Fig. '1 by reference sign |21 and has been shown on an enlarged scale in Figs. 13 and 14.

Rotation of control shaft |6 in a clockwise direction (as viewed in Figs. 8 to 11) causes movement of cam member I|9 from its right position shown in Fig. 8 to its left position shown in Fig. l0. Cam member |'I9 is moved against the action of biasing spring |28 and actuates the toggle mechanism controlling rod |29 from right to left. Tubular extension |2| is provided with two guide members |39 forming a groove |3I therebetween adapted to receive cam member |I9 and to guide it along a straight path.

bracket |34 is in its left position shown in Fig. 9, spring |36 is slightly compressed, and valve body is being pressed against left valve seat 83 by the pressure that prevails in housing 18. If arm |24 and roller |26 are rotated in a clockwise direction (as viewed in Figs. 9 and ll), spring |31 is slightly compressed and4 valve body' 19 held against right valve seat 84.

As shown in Figs. 9 and l1, a portion of the cam surface ||8 of cam member |20 forms an abutment I I8a. adapted to engage roller |26 when spring |59 interconnecting arm |24 and cam member |29 is in its contracted position.

Referring now more particularly to Figs. 13 and 14, the lower surface of roller carrying arm |24 is provided with a depending projection |40 adapted to be engaged by ratchet pawl |'4|. Ratchet pawl |4| is pivotally mounted at |69 on a bracket I6| on a collar |62 pinned at |63 to the control shaft ||6. Thus control shaft ||6 and arm |24 are coupled when projection |40 is engaged by pawl |4I` and the latter is rotated by control shaft ||6 in a clockwise direction, as viewed in Fig. 14. Spring |64 tends to keep ratchet pawl |4| in engagement with projection |49. Ratchet pawl |4| is provided at the lower end thereof with an abutment |65 adapted to engage stationary abutment |66. Upon rotation of control shaft ||6 in a clockwise direction, as viewed in Fig. 14, abutment |65 engages abutment |66, resulting in disengagement of pawl |4I from projection |49.

The operation of the arrangement illustrated in Figs. '7 to 14 is as follows: Upon rotation of insulating column 24 in a direction from the closed to the open position thereof, the blast valve control means are moved from their position shown in Fig. 9 to their position shown in Fig. 11. This results in opening of blast valve 16. thus establishing an arc extinguishing air blast. Rotation of insulating column 24 from the closed to the open position thereof results also in moving the contact operating means from their position shown in Fig. 8 to their position shown in Fig. 10. Complete separation of contacts 4, and 99 and |00, respectively, is achieved at a time when arm |23 has rotated about a predetermined angle. While insulating column 24 and control shaft I6 are still being rotated in a contact separating direction, abutment |65 engages abutment |66, resulting in disengagement of pawl |4| from projection |49. Hence arm |24 and cam member |20 are free to return under the action of springs |59 and |39 to their initial position shown in Fig. 9. This causes valve element 19 to be moved to the leftand pressure to be built up on the axially lower surface of valve element and, after a given time delay, sufcient to effect circuit interruption and to interpose circuit insulation by means of a disconnect switch or otherwise, blast valve 16 recloses and stops further escape of air under pressure out of blast passage 6.

Since the space within casting 9 situated between blast valve 16 and the gap formed between separated contacts 4 and 99 can be kept within relatively narrow limits, there is but little pre-expansion of compressed air during its flow from blast valve 16 to the arcing zone. This tends to minimize the drop in pressure between these two points or, in other words, to increase the interrupting efficiency.

Referring now to Figs. 15, 16 and 17, reference character 4 indicates a stationary tubular contact and reference character 5 indicates a cooperating movable contact. Movable contact 0 is supported by a diilerential type piston |10 which is biased in an upward direction by spring I1 I. Piston |10 is movably arranged in a cylinder |12 having lateral holes |13. Movable contact 5 is tubular and surrounded by two garter springs |14 which are acted upon by spring means |10 tending to separate garter springs |14 in a direction longitudinally of contact 5. Garter springs |14 are current carrying elements for conductively connecting movable contact and cylinder |12. Spring means |15 press garter springs |14 against inclined surface elements on cylinder |12, thus transmitting a force component on garter springs |14 in a direction radially of contact 8. Spring means |15, therefore, have the tendency to press garter springs |14 against cylinder |12 as well as against contact 5, which minimizes the resistance to current flow between these two parts. Cylinder |12 is enclosed in a tubular insulator I9, leaving an annular space |18 between the radially outer surface of cylinder |12 and the radially inner surface of insulator I '9.

A hood 20 dening passages 20a enclosing cooling plates |11 for the products of arcing is arranged above stationary contact 4 and insulator I9. The upper portion of movable contact 5 is surrounded by an annular insulating throat |18 which helps to deionize the arc gap formed between contacts 4 and 5 upon separation thereof. Insulator I9 is held in proper position by clamping means |19. A casting |80 arranged-below cylinder |12 defines two ducts or passages I8| which permit a flow of compressed air from a source of compressed air (not shown) to the gap formed between contacts 4 and 5 upon separation thereof. Passages |8| are in communication with annular space |16 between insulator I9 and cylinder |12, which space forms an immediate coaxial 'extension of passages I8I. Compressed air in space |16 will be admitted through the orices |13 to the top surface of piston |10. Casting |80 further defines a housing |95 for a slide valve element |82 which is adapted to be operated by rotary insulating column 24 and crank mechanism |83.

Rotary column 24 shown in Fig. 15 is supposed to be operated in the same way and by substantially the same means as rotary column 24 of Fig. l. Housing |95 is provided with a port |84 which directly connects passages |8| to housing |95. A port |98 permits compressed air from passages |8| to pass through housing |95 into a lower` end of cylinder |12 when valve element |82 is in the left hand position as shown in Figs. 15 and 16. Passage |85 permits venting to atmosphere oi' compressed air from the side of cylinder |12 situated below piston in case that valve element 82 is moved from its left position'shown in Fig. to the right. If so moved, passage |80 will be uncovered and simultaneously passages |84 will be covered.

It is possible to superimpose a plurality of elements of the kind shown in Figs. 15 and 17, thus forming a circuit breaker column comprising a plurality oi' pairs of cooperating contacts which are connected in series and form series breaks upon contact separation. Fig. 15 indicates the hood and the cooling plates l|11 associated with a pair of cooperating contacts which may be arranged on a lower level in exactly the same way as contacts 4 and 5 shown in Fig. 15. 'I'he lower hood 20 is formed by the same casting |80 which defines supply passages I8I. Assuming only two circuit breaker elements to be superposed, passages |8| of casting |80 connect the annular space |18 of the lower circuit breaker element to the annular space |18 of the upper circuit breaker element illustrated in Figs. l5, 16 and 17, by'bypassing venting hood 20. Gas under pressurentering the lower circuit breaker element and particularly annular space |10 thereof may, in part, escape through the gap formed between the lower contacts 4,` 8 upon separation thereof, and in part rush through passages |8| in the casting |80 to the annular space |18 of the circuit breaker element mounted immediately above and illustrated in Figs. 15, 16 and 17. The venting structure 20a on the top of the circuit breaker column permits escape to Yatmosphere of the air under pressure which reaches the top oi the column only through the gap between the arcing contacts, i. e., it has no bypass means such as passages |8| of casting |80. A circuit breaker column of the general type here referred to is shown in my U. S. Patent 2,558,757, issued July 3, 1951. for Multibreak Gas Blast Circuit Breaker With Grounded Operating Motor. The above mentioned 'patent also shows the configuration of casting |80 and of the ducts or passages 8| and of the` passages formed by the lower exhaust hood 20.

The contact arrangement shown in Figs. 15,

16 and 17 and the contact operating and control means shown in these gures are combined with blast valve and blast valve operating and control means of the kind shown either in Figs. 1,

and 4. In other words, in Figs. 1, 3 and 4, the contact arrangement and the contact operating andl control means may be substituted by the contact arrangementand the contact operating and control means shown in Figs. 15, 16 and 17.

The operation of the structure shown in Figs. l5, 16 and 17 to separate the arcing contacts 4 and 5 is as follows: Rotation of insulating column 24 causes blast valve |0 to open by the means fully described in connection with Figs.l, 2, 3 and 4. Opening of valve I0 results in admission of air under pressure to passages |8|. Air under pressure entering passages I8I in part rushes through the annular space |16 to the space immediately surrounding the arcing contacts, and, in part, through the port |13 of cylinder |12 to the space above piston |10. Part of the air under pressure in passage |8| also rushes through port |84, valve housing |95, port |98, and into the lower end of cylinder |12. Thus, air under pressure in passages |8I is admitted to the top as well as to the bottom of diierential piston |10. Since air pressure is applied simultaneously to both sides of piston |18 and the pressure reactive areas on both sides of piston I 10 are about the same, contacts 4 and 5 will remain engaged for the time being under the action of biasing spring |1|. Continued rotation of column 24 causes valve element |82 to be moved to the right from its lett position shown in Figs. 15 and 16. This causes blocking of passages |84 and dumping of air from the portion of cylinder |12 situated below difierential piston |10 through passage |85 which is Hence differential piston |10 will aseaoos a plurality of superimposed interrupting units,

insulating column 24 will be provided with atacts that it may involve consists in prevalence of substantially equal pressure conditions throughout the entire lengths or height of the circuit breaker column. This can be achieved by permitting a sufficient time delay between opening of the blast valve and separation of the arcing contacts. Dumping of compressed air from the spaces |16 inside insulators I9 through openings |85 involves evidently a certain time element conducive to equalization of pressure conditions throughout the length of a multibreak air blast circuit breaker column.

It will be apparent to those skilled in the art that my invention. is not limited to the particular conditions shown but that changes and modifications may be made without departing from the spirit and scope of my invention, and I aim the appended claims to cover all such changes and modifications.

It is claimed and desired to secure by Letters Patent:

l. In a circuit breaker in combination, a reservoir for gas under pressure, means deflning an insulating blast passage in permanent communication at one end thereof with said reservoir, valve means arranged adjacent the opposite end of said passage for controlling a blast of gas under pressure issuing therefrom, a pair of cooperating relatively movable contacts arranged in the zone of said blast, a motor means arranged substantially at ground potential, and an insulating element adapted adjacent one end thereof to control the operation of said pair of contacts as Well as to control the operation of said valve means, and adapted adjacent the opposite end thereof to be operated by said motor means.

2. In a circuit breaker in combination, a reservoir for gas under pressure, means defining an insulating blast passage in permanent communication at one end thereof with said reservoir, valve means arranged adjacent the opposite end of said passage for controlling a blast of gas under pressure issuing therefrom, a pair of cooperating relatively movable contacts arranged in the zone of said blast, a motor means arranged substantially at ground potential, and an insulating element adapted adjacent one end thereof to operate one of said pair of contacts and to initiate the operation of said valve means, and adapted adjacent the opposite end thereof to be operated by said motor means. a

3. In a circuit breaker in combination, a reservoir for gas under pressure,` means dening an insulating blast passage in permanent communication at one end thereof with said reservoir, valve means arranged adjacent the opposite end of said passage for controlling a blast of gas under pressure issuing therefrom, a pair of cooperating relatively movable contacts arranged in the zone of said blast, a motor means arranged substantially at ground potential, and a rotatable insulating column arranged generally parallel to said blast passage defining means, said column being adapted adjacent one end thereof to control the operation of one of said pair of contacts as well as to control the operation of said valve means, and adapted adjacent the opposite end thereof to be rotated by said motor means.

4. In a circuit breaker in combination, a reservoir for gas under pressure, means defining an insulating blast passage in permanent communication at one end thereof with said reservoir, valve means arranged adjacent the opposite end of said passage for controlling a blast of gas under pressure issuing therefrom, a pair of cooperating relatively movable contacts arranged in the zone of said blast, a motor means arranged substantially at ground potential, and a rotatable insulating column arranged parallel to said blast passage defining means, said column being adapted adjacent one end thereof to operate one of said pair of contacts and to initiate the operation of said valve means, and adapted adjacent the opposite end thereof to be rotated by said motor means.

5. In a circuit breaker in combination, a reservoir for gas under pressure, a hollow insulator in permanent communication at one end thereof with said reservoir, a metal housing arranged at the opposite end of said insulator, a main valve means enclosed within said housing for controlling a blast of gas through said insulator and housing, iiuid motor means for operating said main valve means and forming an integral part of said housing, an auxiliary valve for initiating the operation of said iiuid motor means, a pair of cooperating relatively movable contacts arranged in the zone of said blast, a common motor means arranged substantially at ground potential, and an insulating element adapted adjacent one end thereof to operate one of said pair of contacts and said auxiliary valve, and adapted adjacent the opposite end thereof to be operated by said common motor means.

6. In a circuit breaker in combination, a reservoir for gas under pressure, a hollow insulator in permanent communication at one end thereof with said reservoir, a metal housing arranged at the opposite end of said insulator, a main valve means enclosed within said housing for controlling a blast of gas through said insulator and housing, fluid motor means for operating said main valve means and forming an integral part of said housing, an auxiliary valve for initiating the operation of said fluid motor means, a pair of cooperating contacts arranged in the zone of said blast, a common motor means arranged substantially at ground potential, and a rotatable insulating column arranged substantially parallel to said hollow insulator, said column being adapted adjacent one end thereof to operate one of said pair of contacts and said auxiliary valve, and adapted adjacent the opposite end thereof to be rotated by said common motor means.

'7. In a gas blast circuit breaker, a tubular insulating supporting member, a pair of cooperating relatively movable contacts supported by said member, a reservoir for gas under pressure in permanent communication with said member, valve means arranged adjacent the downstream end of said member for controlling an arc extinguishing blast adjacent said pair of contacts, said valve means being at substantially the same potential as at least one of said pair of contacts, a motor means arranged substantially at ground a reservoir for gas under pressure -substantially at ground potential and in permanent communication with one end of said insulating,r member, a main valve for controlling an arc extinguishing blast of gas from said insulatingr member into said chamber dening means and adjacent said pair of contacts, said main valve being arrangedadjacent the end of said insulating member remote from said reservoir, fluid motor means for 'operating/i said main valve arranged adjacent thereto and at substantially the same potential as said main valve, an auxiliary valve for controlling the operation of said fluid motor means, a motor means arranged substantially at ground potential, and a vertical rotatable insulating column, one end of said column being adapted to control the operation of one of said pair of contacts and actuate said auxiliary valve, and the other end of said column being adapted to be rotated by said motor means.

9. In a circuit breaker in combination, a reservoir for gas under pressure, means defining an insulating blast passage in permanent communication at one end thereof with said reservoir, valve means arranged adjacent the opposite end of said passage for controlling a blast of gas under pressure issuing therefrom, a pair of cooperating relatively movable contacts arranged in the zone of said blast, a motor means arranged substantially at ground potential, a rotatable insulating column arranged parallel to said blast passage defining means, one end of said column being adapted to be rotated by said motor means, a pair of cam means associated with the opposite end of said column, one of said pair of cam means being adapted to control the operation of one of said pair of contacts, and the other of said pair of cam means being adapted to control the operation of said valve means.

10. In a circuit breaker in combination, a reservoir for gas under pressure, means defining an insulating blast passage in permanent communication at one end thereof with said reservoir, valve means arranged adjacent the opposite end of said passage for controlling a blast of gas under pressure issuing therefrom, means defining an extension of said passage substantially parallel thereto and adapted to receive the blast issuing therefrom, a nozzle contact and a cooperating plug contact arranged within said extension defining means and closely adjacent said valve means, operating means for effecting relative movement between said nozzle contact and said plug contact in a direction longitudinal of said extension, a fluid motor arranged substantially at vground potential, and an insulating co1- umn adapted to be rotated about the longitudinal axis thereof and arranged generally parallel to said blast passage and said extension defining means, one end of said insulating column being adapted to control the operation of said operating means and operation of said valve means, and the opposite end of said insulating column being adapted to be rotated by said fluid motor.

11. In a circuit `breaker in combination, a re8 ervoir for gas under pressure, means defining an insulating blast passage communicating permanently at one end thereof with said reservoir, a differential valve adjacent the opposite end of said passage for controlling a blast of gas under pressure issuing therefrom, .an auxiliary' valve adjacent said opposite end of said passage for venting one side of said differential valve, means defining an extension of said passage adapted to receive the blast issuing therefrom, a nozzle contact and a cooperating plug contact arranged within said extension defining means and closely adjacent to said differential valve, operating r means for effecting relative movement between said nozzle contact and said plug contact in a direction longitudinal of said extension defining means, a fluid motor arranged substantially at ground potential, a transmission adapted to be operated by said fluid motor, and an insulating column adapted to be rotated about the longitudinal 'axis thereof and arranged generally parallel to said blast passage and extension defining means, one end of said column being adapted to actuate said auxiliary valve and to control said contact operating means, and the opposite end of said insulating column being adapted to be actuated by said transmission.

12. In a circuit breaker in combination, a reservoir for gas under pressure, a first vertical insulating column defining a blast passage communicating permanently at one end thereof with said reservoir, a valve adjacent the opposite end of said passage for controlling a blast of gas under pressure issuing therefrom, said valve including a movable valve element and guiding means therefor for causing said valve element to move in a direction longitudinal of said passage, means arranged coaxial with respect to to control both said valve and said contact separating means.

' 13. In a circuit breaker in combination, a reservoir for gas under pressure, blast passage insulating means supported by and in permanent communication at one end thereof with said reservoir, a metal housing at the end of said blast passage means remote from said reservoir, a differential valve within said housing for controlling a blast of gas under pressure issuing from said blast passage means, an auxiliary valve adjacent said differential valve for venting one side thereof, a pair of cooperating contacts arranged to be exposed to said blast of gas, contact separating means arranged within said housing for separating said pair of contacts, a fluid motor adjacent the intake end of said blast passage means and substantially at ground potential, a

` first rotatable shaft parallel to said blast pasadapted to constitute a common means for actuating said auxiliary valve and for controlling thev lcent said differential valve for venting one side thereof, a contact operating mechanism within said housing, a pair of cooperating contacts exposed to said blast of gas and adapted to be separated by said contact operating mechanism, a fluid motor adjacent the intake end of said blast passage means and substantially at ground potential, a first rotatable shaft parallel to said blast passage and adapted to be rotated by said fiuid motor, an insulating column supported by and arranged coaxial with respect to said rst shaft, .a second rotatable shaftsupported by said insulating column and arranged coaxial with respect to said first shaft; means associated with said second shaft for controlling both said auxiliary valve and said contact operating mechanism, said last referred to means including means for causing opening of said differential valve only upon rotation of said second shaft in one of both directions and means for causing operation of said contact operating mechanism upon rotation of said second shaft in either of both directions.

15. In a circuit breaker in combination, a reservoir for gas under pressure; means at least in part of insulating material-defining a blast passage in permanent communication at one end thereof with said reservoir and adapted to be supplied with gas under pressure from said reservoir; a blast valve arranged adjacent the opposite end of said passage for controlling a blast of gas under pressure through said passage; a pair of cooperating contacts arranged in the path of said blast; a motor operable by gas under pressure comprising a cylinder and a spring biased piston, said motor being arranged immediately adjacent one of said pair of contacts at the potential thereof and adapted to separate said one of said pair of contacts from the other of said pair of contacts; means for admitting gas under pressure from said blast passage to said cylinder simultaneously on 'both sides of said piston; means for venting said cylinder on one side of said piston only to cause separation of said pair of contacts; an insulating column adapted to be rotated about the longitudinal axis thereof and arranged generally parallel to said blast passage, one end of said column being adapted to control said venting means; and motor means substantially at ground potential operatively related to the other end of said column for rotating said column to cause opening of said venting means to cause separation of said pair of contacts.

` 16. In a circuit breaker in combination, a reservoir for gas under pressure; means of insulating material defining a blast passage in permanent communication at one end thereof with said reservoir; valve means arranged adjacent the opposite end of said passage for controlling a blast of gas under pressure issuing therefrom; a pair of cooperating contacts arranged in the zone of said blast; a motor operable by gas under pressure and comprising a cylinder and a spring biased piston, said motor being arranged immediately adjacent one of said pair of contacts at the potential thereof and adapted to` separate said one of said pair of contacts from the other of said pair of contacts; means for admitting gas under pressure from said blast passage to said cylinder simultanei isly on both sides of said piston;

lmeans for venting said cylinder on one side of said piston only to cause separation of said pair of contacts; an insiilatingvcolumn adapted to be rotated about the longitudinal axis thereof and arranged generally parallel to said blast passage; one end of said column being adapted to control the opera'tion of both said valve means and said venting means, and motor means arranged substantially at ground potential and adjacent the opposite end of said column for rotating said column to control the operation of said valve means and of said venting means tocause opening of said valve means and separation of said pair of contacts. f

17. In a circuit breaker in combination, a reservoir for gas under pressure, means defining an insulating blast passage in permanent communication at one end thereof with said reservoir, a blast valve arranged at the opposite end of said passage for controlling a blast of gas under pressure issuing therefrom, a pair of cooperating contacts arranged. in the path of said blast, a fluid motor for operating said blast valve, an auxiliary valve for controlling the operation of said blast valve'operating fluid motor, a fiuid motor for effecting relative movement between said contacts, an auxiliary valve for controlling the operation of said contact operating fiuid motor, a common insulating element for actuating both said auxiliary valves, and motor means arranged substantially at ground potential for operating said common insulating element.

18. In a circuit breaker in combination, a reservoir for gas under pressure, means defining an insulating blast passage in permanent communication at one end thereof with said reservoir, a blast valve arranged at the opposite end of said passage for controlling a blast of gas under pressure issuing therefrom, a pair of cooperating contacts arranged in the path of said blast, a fluid motor for operating said blast valve, said fluid motor including a differential type piston forming an integral part of said blast valve, an auxiliary valve for controlling the operation of said blast valve operating fiuid motor, a fluid motor for effecting relative movement between said contacts, said fluid motor including a differential type piston forming an integral part of one of said contacts, an auxiliary valve for controlling the operation of said contact operating fluid.

motor, an insulating column rotatable about the longitudinal axis thereof adapted to actuate both said auxiliary valves, and an auxiliary motor means arranged substantially at ground potential for rotating said column.

19. In a circuit breaker in combination, a reservoir for gas under pressure; means at least in part of insulating material defining fa blast passage in permanent communication at one end thereof with said reservoir and adapted to be supplied with gas under pressure from said reservoir; a blast valve for controlling a blast of gas through said passage; a pair of cooperating contacts arranged in the path of said blast; a first fluid operated motor for operating said blast valve, said motor including a differential type piston forming an integral part of said blast valve; an auxiliary valve for controlling the operation of said ilrst motor,l a second iluid oper REFERENCES CITED ated meter for effecting relative movement be" The following references are of-record in the tween said pair -of contacts, said second motor me of this patent:

including a differential type piston forming an integral part of one of said pair of contacts; an 5 UNITED STATES PATENTS auxiliary valve for controlling the operation of Number Name Date said second motor; an insulating column rotat- 2,288,472 MacNeill et al June 30, 1942 able about the longitudinal axis thereof adapted 2,419,447 Geyer et al Apr. 22, 1947 to actuate both said auxiliary valves; and a motor 2,454,586 Amer Nov. 23, 1948 arranged substantially at ground potential for l@ 2,470,623 Ludwig et al. May 17, 1949 rotating said column.

GUSTAN E. JANSSON.