US2706758A - High tension interrupter switches - Google Patents

Description

April 19, 1955 A. THIBAUDAT HIGH TENSION INTERRUPTER SWITCHES Filed March 26, 1952 I H van 2% A/bew Thzbauam i United States Patent HIGH TENSION INTERRUPTER SWITCHES Albert Thibaudat, Paris, France, assignor to Forges et Ateliers de Constructions Electriques de Jeumont, Paris, France, a corporation of France Application March 26, 1952, Serial No. 278,538

Claims priority, application France March 30, 1951 13 Claims. (Cl. 200-148) The present invention relates to improvements in high tension circuit breakers or interrupter switches of the pneumatic blowout type actuated by elastic means and having self-contained means for furnishing compressed air for blowing out the arcs occurring upon opening of the circuit breaker or switch within its full breaking power range.

Apparatus of this type generally employs cylinders and pistons which are actuated by relatively complex and expensive mechanical systems. These systems involve large inert masses and require considerable force to overcome the inertia. Moreover, they are subject to dilficulties by reason of friction, dead air volumes and head losses, so that their mechanical and pneumatic efliciency is very low and the available mechanical energy is poorly utilized. Because of this low efficiency, the opening springs of circuit breakers or switches employing them must be very powerful so that the closing of the circuit breaker or switch requires an undesirably large mechanical force.

It is an object of the present invention to eliminate these disadvantages by providing a particularly simple and inexpensive construction. A further object of the invention is to reduce the number and inertia of the moving parts to a minimum and to eliminate practically all friction while, at the same time, obtaining high pneumatic efliciency of the blowing means.

In accordance with the invention, the arcing chambers of the circuit breaker are supported by hollow insulators mounted on a partition which carries on its opposite face, directly in line with the hollow insulators, blowers of the collapsible type which have an air-volume corresponding to that required for the extinction of full breaking power arcs are actuated concurrently with the opening of the contacts by means of frictionless cams which are driven by opening springs, the moving member of each blower comprising a light pivoted plate or wall which is mechanically joined to the moving contact. In the closed position of the switch, the moving contact preferably closes the exhaust of the arcing chamber. Upon the opening of the switch, the moving contact leaves the arcing chamber, thereby permitting the air supplied by the blower to be discharged under pressure.

In comparison with blowers heretofore proposed, those of the present invention are distinguished particularly by their special arrangement of the air compressing and switch operating means upon a supporting wall, this arrangement making it possible to substantially improve the pneumatic efiiciency of the blow-out action with respect to prior constructions. The invention is further distinguished by a special arrangement of the operating mechanism, which is of very simple construction and works with a very high mechanical efficiency, and by other improvements which will be described below. These characteristics make it possible greatly to reduce the mechanical forces required for operation of the circuit breaker and blower and to assure, despite the great simplicity of the construction, a reliable and efficient operation of circuit breakers having high interrupting capacity.

Other objects and advantages of the invention will appear from the following description and claims in conjunction with the accompanying drawings, in which:

Fig. 1 is a diagrammatic side view, partly in section, showing a blower embodying the present invention.

Fig. 2 is a similar view showing another embodiment.

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Fig. 3 is a similar, though more complete, view showing a modification of Fig. 1.

In the embodiment illustrated in Fig. 1, a wall or partition 1 carries on one side a tubular insulator 2 supporting an arcing or interrupting chamber 3 of any suitable type for pneumatic blowout of the are occurring on the opening of the switch. The partition 1 is provided with an opening 4 in line with the hollow insulator 2. On the other side of the partition 1, and directly over the opening 4, there is provided a blower in the form of a compressible and elastic receptacle 5 having a volume which corresponds to that required for the extinction of full breaking power arcs of the interrupter. This receptacle may be spherical or elongated in shape and, in the latter case, may be provided with a plurality of holes communicating respectively with a corresponding number of hollow insulators in order to blow the several poles of a polyphase circuit breaker. It is preferably made of rubber or other elastomeric material having similar properties and has such wall thickness as to be selfsustaining and to return automatically to the position shown in Fig. 1 while, at the same time, being readily compressible or collapsible.

The elastic receptacle 5 is compressed by a light wall or plate 6 which is pivotally connected to the partition 1 at 6A and carries a roller 7 which is engaged by a rotary cam 8 mounted on a rotary drive shaft 9. The roller 7 provides substantially frictionless engagement with the cam. A connecting rod 10 connects the roller 7, and hence the plate 6, to a movable member carrying the roving contact of the circuit breaker. This arrangement may be of any appropriate kind, as, for example, illustrated in Fig. 3. It is preferably such that the air exhaust opening of the interrupting chamber is closed by the moving contact when the switch is in closed position.

The shaft 9 and cam 8 are biased in the direction of the arrow by a previously wound opening spring which is confined by a suitable catchas, for example, shown in Fig. 3when the switch is closed. When the spring is released, the cam 8 rotates in a counterclockwise direction, as viewed in Fig. 1, and, by engagement with the roller 7, swings the plate 6 toward the partition 1, thereby compressing the elastic receptacle 5 and forcing air through the hollow insulator 2 to the chamber 3. The linkage between the plate 6 and the moving contact of the interrupter is preferably such that compression of the receptacle 5 produces a preliminary compression of the air in the receptacle and thereafter the connection rod 10 produces an opening of the moving contact so that the air is blown out with considerable force. Suitable arrangements of the moving contacts and connecting linkages are shown in Figs. 2 and 3.

It will be seen that, with this arrangement, the path of the air, the amount of dead space, the amount of friction, the number of moving parts and the effects of inertia are all reduced to a bare minimum. It is thereby possible to use a lighter release spring-since less force is required to open the switch and blow out the arc-and this in turn facilitates the closing of the switch as it is easier to overcome the force of the lighter spring.

In the embodiment shown in Fig. 2, the blower is in the form of a collapsible receptacle comprising a portion of the partition 1, including the opening 4, a metal hood 11 mounted on the partition and having the form of a sector of a cylinder and a light plate 12 which is pivotally connected to the partition 1 at 12C and swings inside the hood 11 with a slight clearance between the plate and hood. The plate 12 carries a roller 7-as in Fig. 1which is engaged by a rotary earn 8 actuated by the opening spring, as previously described. As the plate 12 swings in a counterclockwise direction from the position shown in Fig. 2, it compresses the air enclosed in the receptacle, forcing it through the opening 4 and hollow insulator 2. An insulated arm 10B rigidly connected to the plate 12, and hence swinging with said plate, is connected by a link 10C with the movable contact 13 of the circuit breaker so as to open this contact when the wall 12 is swung toward the partition 1. The movable contact 13 biased by a closing spring 13A, co-

fixed contact, the external circuit controlled by the cir- 3 cuidt 1gareaker being represented by the connections A an To facilitate the rapid return of the plate 12 to the position shown in Fig. 2, when the switch is closed, the plate is preferably provided with a check valve 14 which is shown in the form of a hinged flap overlying an opening in the plate 12. This valve has the additional advantage of preventing-during the closing of the switchthe suction of ionized gases inside the metal blower which is at ground potential. The tightness of the blower is improved without increasing friction by wide turned back edges 22A which are provided on the outer edge and end edges of the moving part 12. Flexible packing 12B or other appropriate sealing means can also be provided between the pivoted wall 12 and the hood 11, if desired.

The application of the invention to a particular circuit breaker is shown in greater detail in Fig. 3. This figure also illustrates the simplicity and effectiveness of the construction in accordance with the invention.

In Fig. 3, the interrupting chamber 313 is shown provided with a suitable blowout nozzle 15. This nozzle cooperates with a moving contact 16 which closes the nozzle in closed position of the switch. The moving contact 16 is carried by an arm 17 which is movably supported by a conducting spring 18 attached to a supporting insulator 19 mounted on the partition 1. The connections A and B go to the high tension circuit controlled by the switch.

A blower A mounted on the partition 1 directly opposite the hollow insulator 2 which supports the separating chamber 313 is similar to the blower 5 of Fig. l but is modified to include the check valve structure 14- of Fig. 2. The elastic blower receptacle 5A is compressible by the pivoted plate 6A which, as in Fig. 1, is swung in a counterclockwise direction by means of a cam 8 which engages a roller 7 on the plate 6A. The pivoted plate is connected to the arm 17 carrying the moving contact 16 by means of a connecting rod 10 which has an insulator 10A since the part 17 may be at high voltage.

The cam 8 is biased in the direction of the arrow F by a spiral opening spring 20. The cam is held in the closed position of the switch, as shown in Fig. 3, by a control lever 25 which is pivotally supported at 26 and carries a catch 21 engaging a detent portion 21A on the cam 8. A light spring 22 holds the control lever 25 in locking position, as shown in Fig.3.

When the catch 21 is released, for example by hand or by a suitable remote control or an overload relay, the release spring 20 is freed and causes the cam 8 to turn in the direction of the arrow F, swinging the pivoted plate 6A in a counterclockwise direction to compress the blower 5A and-through the link 1dmoving the arm 17 carrying the movable contact toward the left. After a predetermined preliminary period of compression of the air, the contact 16 comes out of the nozzle 15 and the resulting arc is blown out by the compressed air. The open position of the contact is indicated by the broken lines 16A. An arm 23, which is integrally connected with the plate 6A, swings in the direction of the arrow 1' and, when the switch is open, reaches a position in which it is blocked by a resilient second catch 24 on the control lever 25 so that the switch is kept in its open position.

In order to re-close the switch, the shaft 9 and cam 8 are turned in a clockwise direction and the release spring 20 is thus wound up. During this movement, the elements 6A, 23, 17 and 16 at first remain immobile but, when the cam 8 reaches the position illustrated in Fig. 3, the catch 21, under tension of the spring 22, suddenly engages with the detent 21A of the cam 8. This engagement results in a slight counterclockwise movement of the control lever 25, causing the catch 24 to be displaced toward the right, thereby freeing the arm 23 so that the switch is rapidly closed by the action of the closing spring 18 which is biased to move the parts to closed position. The plate 6A swings in a clockwise direction until it is stopped by an abutment 27. During this movement of the plate, the check valve 14 opens to admit air to the blower 5A.

It will be seen that, despite its great simplicity, the circuit breaker works effectively and with high efficiency while, at the same time, embodying several advantageous properties, such as an energetic blowing action, rapid closing and opening of the circuit breaker, pneumatic absorption of the movement, small fioor space and visible opening of the contacts. The invention thus makes it possible to manufacture completely self-contained pneumatic blowout-type high voltage circuit breakers or interrupter switches very economically, said switches having remarkable interrupting capacity and having all the safety properties required in operation.

It will be understood that the arrangements shown in the drawings and particularly described can be modified in various ways within the scope of the invention. The individual features of the several embodiments are mutually interchangeable and the cams shown in the drawings may be replaced by toggle joints or other mechanical movements which are free from friction for all practical purposes.

What I claim and desire to secure by Letters Patent is:

1. In a high tension pneumatic blow-out interrupter switch of the kind having an opening spring, a self-generating gas blast structure, a movable contact operative in conjunction therewith, an arcing chamber, a tubular insulator carrying said chamber, a partition supporting said insulator, a blowing nozzle on said chamber, said nozzle being closed by said movable contact in the closed position of the switch, operating means for improving the mechanical and pneumatic efiiciency of the interrupter to reduce the required power of said spring, said operating means comprising a collapsible blower having an air volume corresponding to that required for the extinction of the full breaking power arcs of the interrupter and communicating directly with said insulator and chamber, a plate pivotally mounted on said partition and swingable about its pivot to operate said blower, mechanical connections between said pivoted plate and the movable contact, a roller on said plate, a cam engaging said roller to swing the plate about its pivot and biased by said spring in a direction to move said plate to operate said blower and to open said interrupter.

2. In a high tension pneumatic blow-out interrupter switch of the kind having an opening spring, a selfgenerating gas blast structure, a movable contact operative in conjunction therewith, an arcing chamber, a tubular insulator supporting said chamber, a blowing nozzle on said chamber, said nozzle being closed by said movable contact in the closed position of the switch, a simplified arrangement for improving the mechanical and pneumatic efficiency of the interrupter to reduce the required power of said spring, comprising a vertical wall having an aperture, the tubular insulator being mounted over said aperture on one side of the wall, a blower of the collapsible type having an air-volume corresponding to that required for the extinction of the full breaking power arcs of the interrupter, said blower being mounted on the opposite side of the wall and communicating directly with the tubular insulator through said aperture, a plate pivotally mounted on the wall and swingable about its pivot to collapse said blower, mechanical connections between said pivoted plate and the movable contact, a roller on said plate, a rotary cam engaging said roller and biased by said opening spring for applying a torque to turn said cam in a direction to swing said plate to collapse said blower and to open said switch.

3. In a high tension pneumatic blow-out interrupter switch of the kind having an opening spring, a self-generating gas blast structure, an arcing chamber, a tubular insulator carrying said chamber, a wall supporting said insulator, a blowing nozzle on said chamber and a movable contact operative in conjunction with said gas blast structure and adapted to close said nozzle in the closed position of the switch, a simplified arrangement for improving the mechanical and pneumatic efiiciency of the switch to reduce the required power of said opening spring, comprising a blower of the collapsible type having an airvolume corresponding to that required for the extinction of the full breaking power arcs of the switch, and an opening connected directly with said tubular insulator, a plate pivotally mounted on said wall and swingable about its pivot to collapse said blower, mechanical connections between said plate and the movable contact, a roller on said plate, said opening spring being biased to turn said cam in a direction to swing said plate to collapse said blower and to operate said movable contact.

4. In a high tension pneumatic blow-out interrupter switch of the kind having an opening spring, a self-generating gas blast structure, an interrupter chamber, a tubular insulator supporting said chamber, a blowing nozzle on said chamber and a movable contact operative in conjunction with said gas blast structure which closes said nozzle in the closed position of the switch, a simplified arrangement for reducing the power of said spring, comprising a vertical wall having an aperture, the tubular insulator being mounted over said aperture on one side of said wall, a blower of the collapsible type having an air-volume corresponding to that required for the extinction of the full breaking power arcs of the switch, said blower being fixed on the opposite side of the wall and comprising a portion of said vertical wall including said aperture, a sector-shaped hood mounted on said vertical wall and having spaced end walls and a curved outer wall and a plate pivotally mounted on said vertical wall and swingable in said hood with slight clearance between said plate and hood, mechanical connections between said plate and the movable contact, a roller on said plate, a rotary cam engaging said roller and biased by said opening spring to turn said cam in a direction to swing said plate toward said vertical wall and thereby force air through said tubular insulator, arcing chamber and nozzle.

5. A high tension interrupter switch according to claim 4, in which said plate has an opening and a valve flap pivotally mounted on the inner side of said plate to close said opening.

6. A high tension interrupter switch according to claim 4, in which the edges of said plate are turned back to provide portions which lie close to and approximately parallel to the adjacent portions of said hood.

7. In a high tension interrupter switch of the kind having an opening spring, a self-generating gas blast structure, an arcing chamber, a tubular insulator supporting said chamber, a wall supporting said insulator, a blowing nozzle in said chamber and a movable contact operative in conjunction with said gas blast structure and adapted to close said nozzle in the closed position of the switch, operating means for improving the mechanical and pneumatic efficiency of the switch comprising a movable arm carrying said contact, a conducting spring mounted on the support and carrying said movable arm, said spring tending to close the switch, a collapsible blower having an air-volume corresponding to that required for the extinction of the full breaking power arcs of the switch, said blower being directly connected with said tubular insulator and comprising a plate pivotally mounted on said wall, an insulating link between said plate and the movable arm carrying said movable contact of the switch, a roller on said plate, a rotary cam engaging said roller, said opening spring being attached to said cam and applying a torque to the cam in a direction to swing said plate to collapse said blower and open the switch, a pivoted tripping lever having a catch for releasably holding said cam normally in the closed position of the switch, and a second catch for releasably holding said pivoted plate in the open position of the switch.

8. In a high tension circuit breaker of the air blast type having an opening spring, a self generating gas blast structure, movable contacts operative in conjunction with said structure, and are suppression chambers supported by hollow insulators mounted on a partition, simple and highly efficient means for blowing out the arcs and operating said contacts comprising collapsible blowers having an air-volume corresponding to that required for the extinction of the full breaking power arcs of the circuit breaker, said blower being directly mounted on the side of said partition opposite said insulators and connected directly with said insulators, a light weight wall pivotally mounted on the same side of the partition as the blowers and swingable about its pivot to operate the blowers, a roller on said wall, a cam cooperating with said roller to swing said wall about its pivot to operate the blowers, mechanical connections between said light wall and the movable contacts of the circuit breaker, said circuit breaker opening spring being connected to said cam and biased to move said cam in a direction to swing said light wall to open the circuit breaker and operate the blowers.

9. In a high tension pneumatic blow-out circuit breaker of the kind having an opening spring, a self-generating gas blast structure, are suppression chambers, hollow insulators supporting .said chambers, a partition carrying said insulators and movable contacts closing the exhaust of said chambers in the closed position of the circuit breaker,-means for reducing the power of said spring comprising collapsible blowers having an air-volume corresponding to that required for the extinction of the full breaking power arcs of the circuit breaker, said blower being mounted on the side of the partition opposite the said tubular insulators and connected directly with said tubular insulators, a light weight wall pivotally mounted on the same side of the partition as the blowers and swingable about its pivot to operate the blowers, a roller on said wall, mechanical connections between said wall and the movable contacts of the circuit breaker, trip means for releasably holding said spring in the closed position of the circuit breaker, and a cam movable by said opening spring and cooperating with said roller to swing said wall about its pivot in a direction to oper- 1ate tge blowers and the contacts when said spring is reease 10. In a pneumatic blow-out type high tension circuit breaker having an opening spring, a self-generating gas blast structure, are suppression chambers, hollow insulators supporting said chambers, a partition on which said insulators are mounted, a spring for opening the circuit breaker and movable contacts which close the exhaust of said chambers in the closed position of the circuit breaker, means for improving the mechanical and pneumatic efficiency of said breaker and reducing the power of said opening spring, comprising collapsible blowers having an air-volume corresponding to that required for the extinction of the full breaking power arcs, said blowers being connected with the inlet of said hollow insulators and disposed on the opposite side of the partition, a light wall pivotally mounted on the same side of said partition as the blowers and swingable about its pivot to operate the blowers, a roller on said wall, a cam movable by said spring and acting upon said roller on said pivoted wall to swing said wall in a direction to operate the blowers, means for releasably blocking said cam in the closed position of the circuit breaker, and means for mechanically connecting said pivoted wall and the movable contacts.

11. A high tension circuit breaker according to claim 10, in which the blowers comprise compressible elastic receptacles.

12. A high tension circuit breaker according to claim 10, in which each of said blowers comprises a portion of said partition, a metal hood on said partition and said pivoted plate, said plate being formed with wide bent-over edges which have close clearance relative to said hood.

13. In a pneumatic blow-out type high tension circuit breaker having an opening spring, a self-generating gas blast structure, are suppression chambers, hollow insulators supporting said chambers, a partition on which said insulators are mounted, movable contacts which close said chambers in the closed position of the circuit breaker, and conducting springs supporting said movable contacts and biased to close the circuit breaker, improved means for opening the circuit breaker and concurrently supplymg air blasts to extinguish full breaking power arcs occurring on the opening of the circuit breaker, comprising collapsible blowers having an air-volume corresponding to that required for the extinction of said arcs, said blowers being connected with said hollow insulators and mounted on the opposite side of the partition, a light wall pivotally mounted on the opposite side of said partition as the blowers and swingable about its pivot to operate the blowers, mechanical connections between said wall and said movable contacts to provide concurrent operation of the blowers and opening of the contacts, and a cam movable by said spring to swing said wall to operate the blowers and to open said circuit breaker, a latch for releasably holding said cam in closed position of the circuit breaker, and a catch for releasably holding said movable contacts in open position.

References Cited in the tile of this patent UNITED STATES PATENTS 1,414,913 Whittingham May 2, 1922 2,055,312 Ruppel Sept. 22, 1936 2,303,730 Fernier Dec. 1, 1942 2,430,008 Fernier Nov. 4, 1947 2,552,427 Heidmann May 8, 1951

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