US2112071A - Circuit interrupter - Google Patents

Description

. March 22, 1938. 1-1. J. CRABBS CIRCUIT INTERRUPTER Original Filed Aug. 15, 1934 3 Sheets-Sheet l INVENTOR J%z//-//rmwj ATTORN Y March 22, 1938. H. J. CRABBS CIRCUIT INTERRUPTER Original Filed Aug. 15, 1934 3 Sheets-Sheet 2 INVENTOR WITNESSES: L

March 22, 1938. H. .J. CRABBS CIRCUIT INTERRUPTER s Shets-Sheet Original Filed Aug. 15, 1934 WITNESSES:

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ATTORNEY Patented Mar. 22, 1938 UNITED STATES KHSSUH) MAR 18 1947 2,112,071

PATENT OFFICE CIRCUIT INTERRUPTER Pennsylvania Application 24 Claims.

My invention relates generally to circuit interrupters, and it has particular application to disconnecting switches of either the outdoor or the indoor type.

Disconnecting switches are used principally for sectionalizing or isolating portions of a transmission line or a power distribution network, and, in their simplest form, the devices usually comprise little more than a knife switch of the proper capacity which is provided with a suitable latching means for preventing undesired openings of the circuit. In their normal operation, the switches are rarely called upon to interrupt any considerable amounts of power, and in fact, the switches known to the art in the past have been quite incapable of opening more than very small amounts of power, particularly at high voltages.

With the increased growth of interconnected power networks and transmission systems it has become increasingly important that these sectionalizing and isolating switches shall be capable of opening at least moderate amounts of power, and the older type of switches has proven unsatisfactory for this service. In fact, if voltages in the neighborhood of 100 kv. are used, an ordinary knife blade disconnecting switch is incapable of opening even the line charging current without danger of drawing long uncontrolled arcs which may short circuit and seriously damage adjacent equipment.

Various expedients for obviating these difficulties have been proposed and some of them have been tried. None of the proposed arrangements, however, has been entirely satisfactory. Some are too expensive and thereby economically impractical, since large numbers of the devices must be used in even a moderately sized transmission line. Others are not entirely safe in operation, and even the best of the prior art devices has not been a commercially successful development.

The principal object of my invention, therefore, is to provide a disconnecting switch which shall be capable of opening circuits carrying considerable amounts of power and which, at the same time, shall be relatively low in cost.

Another object of my invention is to provide an improved disconnecting switch which shall be simple in design and rugged in construction, which shall be absolutely reliable in operation, even when subjected to the adverse weather conditions, and which includes means for interrupting the are which may be established incident to the opening of the circuit.

A further object of my invention is to provide means whereby an expulsion-type circuit inter- August 15, Renewed March 4, 1937 1934, Serial No. 739,891

rupter may be combined with a blade-type disconnecting switch in such manner that a single operating mechanism may be utilized for actuating both the blade and the expulsion-type device.

In accomplishing these objects of my invention I provide, in the preferred embodiment of my device, a three-insulator vertical break disconnecting switch. As in the conventional structure of this type, one of the insulators is rotatable and is connected to the blade by suitable linkages in order that the blade may be swung to the open and to the closed-circuit position by rotating the insulator column. In addition, I provide a tube of insulating material having a length substantially equal to the separation of the stationary insulator columns, a conducting member movable through the tube to provide an electrical circuit in parallel with the blade, and an actuating mechanism intermediate the conducting member movable through the tube and the rotatable insulator.

The various parts are so correlated that during the opening operation the blade is swung from the closed-circuit position to the open circuit position while the conducting means disposed within the tubular member carries the current flowing through the device. Then, as the opening operation progresses, the conducting means moves through the tubular member so as to establish the are formed incident to the opening of the controlled circuit within the passage therein. This tube acts as an expulsion-type circuit interrupter and effects the extinguishment of the are within a short period of time.

Later, the tubular member itself is swung so as to cause an air break to exist in the electrical circuit through the switch. The tube is preferably lined with a material that is capable of evolving an arc extinguishing gas when placed in proximity to an electric arc in order to intensify the expulsive eiiect, and the dimensions of the conducting means are such that the tube is closed at one end during the are drawing operation for the same reason.

The principles and the mode of operation of my invention will be made more apparent by reference to the accompanying drawings, where in I have disclosed the structural details of a disconnecting switch which includes the principal elements of my invention.

Figure 1 is an elevational view, partially in section of a three-insulator disconnecting switch embodying the principal features of my invention; the switch is illustrated in the closed circuit position;

Fig. 2 is a plan view of the switch shown in Fig. 1:

Fig. 3 is a fragmentary view showing the position of the various moving parts of the switch illustrated in Figs. 1 and 2 in the partially open position;

Fig. 4 is a fragmentary view of the rotatable insulator and portions of the blade and the blade supporting means; the various structural elements are shown in the fully open position;

Fig. 5 is an enlarged detail view of the flexible conducting means forming a part of the expulsion unit circuit interrupter,

Fig. 6 is'a sectional view taken on the line VI-VI of Fig. '1 showing the details of construction of the actuating mechanism for the expulsion unit; and

Fig. 7 is a plan view of the actuating mechanism for the expulsion unit.

All but a portion of the closure cover has been cut away to more clearly illustrate the structural features involved.

The preferred embodiment of my invention comprises generally a base I, which may be formed from a channel-shaped section of structural steel or the like, a pair of stationary insulators 3 and 5 mounted upon the base channel I through the agency of suitable bolts 1 which engage the flanges 9 forming a part thereof, and a rotatable insulator ll supported upon the base by means of a suitable ball bearing i3. A jaw member I5 is positioned upon the top of the right hand insulator column 5 and is adapted to be engaged by the movable end l9 of the bifurcated blade member H which is supported upon a suitable U-shaped yoke member 2| aflixed to the other stationary insulator column 3.

A metallic closure 23 wherein the actuating mechanism 25 for the expulsion-type unit is contained, is likewise positioned upon the second stationary insulator column 3. The rotatable insulator I has a shaft portion 21 which extends through the left-hand end of the closure 23 and is adapted to be keyed to the main actuating crank 29 for the blade member. This crank 29 is connected to the blade member l1 through a tie-member 3| and a pair of universal joint linkages 33 and 35.

'The expulsion-type circuit interrupting means which is utilized for extinguishing the arcs which are formed incident "to the opening of the cir cuit controlled by the switch, includes a hollow tubular member 31, preferably of fibre which has been suitably water-proofed on the outer side. This tubular member defines the walls of an arc passage and is adapted to be pivotally supported upon a clamp member 39 aflixed thereto adjacent the left hand end. A pair of spring clips 4| affixed to the blade |1 normally support and position the tubular member with respect to that member. The clamp member 39 is journalled upon the pivot pin 43 for the blade H in order that the tube 31 and the blade means I1 may be independently movable. A spring 45 is disposed intermediate the blade member l1 and the tubular member 31 in order that those two members shall normally be biased into engagement with each other, as is shown in Figs. 1 and 4, and also in order that the tubular member 31 can be caused to automatically swing to the normal open-circuit position subsequent to the opening movement of the blade itself. The left-hand end of the tubular member 31 terminates in a funnel-shaped portion 49 through which the flexible conducting meansil extends into the arc passage within the tube.

This flexible conducting means 5| is shown particularly in Fig. 5 and comprises a closely wound spring 53 having a flexible conducting shunt 55 positioned within the central opening therein. The right-hand end of the spring is rigidly affixed to a suitable contact member 55,,

the body portion 55 of which is preferably of copper and the extreme end portion 51 of which is preferably of a conducting, arc resisting material. The spring 53 is of considerable strength while at the same time, it possesses a considerable amount of flexibility. Its maximum diameter is slightly less than the maximum diameter of the arc passage within the tubular member 31 wherein it is adapted to move, and it becomes immediately apparent that the operation of this conducting means will very closely approximate that of the cable release utilized on the ordinary hand camera. In other words, the conducting means 5| while being sufflcientLy flexible to permit the tubular member 31 to be swung to the open circuit position while it is moved therewithin, is of sufllcient strength and rigidity that the operation of the device is reliable and positive. The flexible shunt 5| is provided for increasing the maximum current-carrying capacity of the conducting means 5|.

For moving the flexible conducting means within the arc passage, the walls of which are defined by the tubular member 31, I prefer to provide an actuating mechanism such as that shown particularly in Figs. 6 and 7. Essentially, this mechanism comprises little more than a grooved drum 6| whereon the flexible conducting means 5| is wound and from which it is unwound during the operation of the switch, and suitable gear means for interconnecting this drum with the rotatable insulator The drum itself is provided with means whereby it is directly connected to the gearing elements during the closing operation but is connected through a lost-motion spring means during the opening operation. By this arrangement, it is possible to move the blade H to the full open position before the circuit through the switch is opened by the expulsiontype interrupting means. Moreover, as the blade |1 nears its uppermost position, the energy charged in the lost motion spring means, by virtue of the relative movement of the gear elements while the drum remains stationary, is released so as to cause the flexible conducting means 5| to move through the arc passage at high speed, thereby establishing the are within that passage.

Specifically, the actuating mechanism for the expulsion-type arc extinguishing means comprises the metallic closure 23 mentioned above, a gear member 63 adapted to be keyed to the upwardly extending shaft portion 21 of the rotatable insulator, a second gear wheel 65 journalled upon a suitable shaft member 61 and having a pinion portion 69 for engaging the first-mentioned gear wheel and a wheel portion 1| for engaging the gear 13 which actuates the drum. This latter gear 13 is keyed to a second shaft 15 which is supported upon a suitable ball bearing 11 afllxed to the base of the closure 23. The drum 5| is journalled upon this second shaft 15 and is connected to its actuating gear 13 by means of a coil spring 19.

Afllxed to the upper portion of the grooved drum BI is a notched wheel 8|, which is utilized for assuring that the electrical circuit through the switchshallalwaysbeflnsllyopenedbytheexpulsion type arc extinguishing means. A ratchet II is supported upon this notched wheel ti and is adapted to engage a suitable ratchet wheel II which is keyed to the shaft 15. A latch member 81, pivotally supported upon the upper half of the closure 73 by means of a screw OI, is provided for engaging the notched wheel 8i. One end of this latch member l'l pivotaily engages one end of an actuating member 9|, the other end 01' which is slidably supported upon a screw II, a!- flxed to the upper portion of the closure 28. This actuating member includes a pair of outwardly projecting portions 55 and SI which are adapted to engage a cooperating portion 91 formed integral with the gear wheel 63.

Through the arrangement of the latch 81 and the ratchet means 03 the drum 5| is prevented from rotating toward the open-circuit position during the greater portion of the opening movement of the rotatable insulator II, and it is only when the projecting portion 91 of the gear wheel 63 engages the outwardly projecting portion 80 of the latch actuating member 9! near the end of that movement that the latch 51 disengages the notched wheel 8| so as to permit the spring I9, which has been stressed by virtue of the relative movement of the drum GI and the actuating gear 13 therefor, to rotate the drum to the normal open-circuit position, thereby drawing an are within the arc passage deflned by the tubular member 31. The ratchet 83 serves to prevent any relative movement of the drum Cl-and the actuating gear 13 therefor during the circuitclosing operation, and thereby assures that the flexible conducting means 5| shall move outwardly through the tubular member 31 and engage the cooperating conducting means 99 supported upon the outboard stationary insulator 5 as the inter rupter is moved to the fully closed position.

The conducting means 99, which is adapted to be engaged by the solid contact portion 55 of the flexible conducting means 5|, preferably comprises an up-extending member rigidly afllxed to the support plate llll for the jaw l5 and having a suitably proportioned opening therein for engaging the sides of the contact portion 55. It is desirable that this conducting means 9! be provided with a certain amount of resilience in order that the proper contact pressure may be secured between the cooperating contact surfaces.

A pair of flexible conducting shunts I03 are utilized for interconnecting the blade means I! with the metallic closure 23 for the interrupter actuating means. This closure 23, in turn, is electrically connected to the other support plate I05 which serves as a terminal for the device. The shunt 5| and the associated contact means 55 for the expulsion type interrupter are electrically connected to the support plate I05 afllxed to the top of the right-hand insulator through the actuating mechanism 25.

A tubular member I01 of insulating material is disposed within the outer wall of the closure 23 for the purpose of guiding the flexible conducting means 5i during the operation of the switch, and a suitably proportioned hollow cylindrical member I09 is positioned about the drum SI for assuring that the flexible conducting means shal be moved thereby without kinking.

The circuit interrupter is shown in the closedcircuit postiion in Figs. 1 and 2, and the actuating mechanism is likewise shown in the closedcircuit position in Figs. 6 and 7. It will benoted that the center line of the actuating linkage for theblade l l (thecrankflandthetielinkll) is totheleftotthecenterlineottheswitch. By this arrangement, the blade is eii'ectively latched in when the switch is in the cloud-circuit position, because the pivot pin Ill intermediate the actuating crank and the tie-linkage must be moved across the center line of the switch (Fig. 2) before the interrupter can be opened (rotation of the insulator II in the counter-clockwise direction being prevented by a suitable stop).

To open the switch the rotatable insulator II is turned in a clockwise direction (Fig. 2). This movement is directly transmitted to the main operating crank II and the tie link 3| intermediate that crank and the blade, and as it progresses, it causes the blade ll to be lifted from the position shown in Fig. 1 toward the open-circuit position shown in Fig. 4. At the same time, the gears intermediate the rotatable insulator II and the drum ll to which the flexible conducting means II is afllxed are likewise rotated. Rotation of the drum 5|, however, is prevented by virtue of the fact that the projecting portion H3 01' the latch 81 engages the notched wheel ll which is directly keyed to the drum itself. Thus, the only eflect of the rotation of the rotatable insulator ll during the initial stages of the circuit-opening operation, so far as the expulsion type unit is concerned, is to store energy in the spring I! intermediate the drum 5i and the gear means. However, as the rotatable insulator II and the blade II approach the fully open position, the outwardly projecting portion 91 01' the first gear 53 engages the cooperating lower portion 95 of the latch actuating member 9| and causes the latch to disengage the notched wheel. The energy in the spring is then released, and as a result, the

drum BI is rotated at high speed, thereby causing the flexible conducting means 5i to be moved longitudinally through the tubular member 31 which defines the walls of the arc passage. This movement takes place at very high speed, and the arc incident to the opening of the circuit controlled by the interrupter is perforce drawn within the tube.

While the blade member I1 is being moved to the open-circuit position, the spring 45 which tends to keep the blade member I! and the tube 31 in their normal aligrmient, is stressed, and immediately following the movement of the end portion 55 or the flexible conducting means 5i out of engagement with the cooperating conducting means 99 disposed on top oi the righthand stationary insulator 5, the tube 31 becomes free to move under the influence of this spring. As a result, the tube 31 rotates from the position shown in Figs. 1 and 3 to the position shown in Fig. 4, in which position the spring clips ll reengage the tube so as to hold it and the blade in their normal respective positions.

The closing operation diflers to a slight degree from the opening operation. The rotatable insulator II is rotated in a counter-clockwise direction and this movement is directly transmitted to the blade I1 and the tubular member 31 supported thereon. As a result, both of those members are simultaneously moved from the position shown in Fig. 4 to the position shown in Fig. l, the electrical circuit being initially established between the blade member H and the contact jaw l5. During this movement, the gear actuating mechanism 25 intermediate the rotatable insulator ii and the drum 5| causes the drum to rotate so as to move the flexible conducting means 5| outwardly through the tubular are passage in the direction of the outboard insulator, the drum 6| being directly connected to the gear mechanism by means of the ratchet U1 and the ratchet wheel 85. In the final stages of the closing movement the outer end 55 of the flexible conducting means II is caused to re-engage the cooperating member 99 supported upon the outboard insulator, and the latch 81 is moved so as to cause a re-engagement of the notched wheel with the cooperating portion Ill of the pivoted latch member.

From the foregoing, it will be seen that the electrical circuit through the switch is always finally interrupted by the expulsion type circuit interrupting device, which has a considerably greater are interrupting capacity than the blade alone, regardless of how rapidly the blade might be moved. Also, the closing operation of the switch is so controlled that excessive currents are prevented from flowing through the expulsion type arc extinguishing means, the circuit through the switch being initially closed through the blade member.-

The tubular member 31 which defines the walls of the arc passage is preferably of fibre, as mentioned above, for the reason that this material is capable of evolving very considerable amounts of arc extinguishing gas when placed in proximity to an electric arc, and because that material can be weather-proofed comparatively easily. It is within the province of my invention, however, that other suitable materials could be used, and if desired, a refractory tube which is lined for at least a portion of its length, with a material capable of evolving a suitable arc extinguishing gas, might be used.

The end portion 55 of the conducting member is preferably of substantially the same size and the same outline as the arc passage within the tubular member, in order that it may serve to close one end of that passage during the circuitopening operation. By this means, since the other end is normally open, the arc extinguishing gas is caused to flow longitudinally through the arc passage in venting, and thus,by its expulsive action, effects an efllcient extinguishment of the are. A round arc passage has been shown and described in the drawings. It is obvious, of course, that other cross-sectional outlines could be used, and it is my intention that the term tubular should include such other outlines.

The actuating mechanism which has been shown in the preferred embodiment of my invention is, of course, but one of the many mechanical arrangements which might be used for effecting the operation of a device embodying the features of my invention. These other arrangemnts will suggest themselves to those skilled in the art, and it is my intention that the accompanying claims should cover such other schemes.

In the foregoing description of my invention, I have described a new form of disconnecting switch which is particularly suitable for use with present-day transmission network distribution systems. My improved disconnecting switch is capable of interrupting considerable amounts of power without danger of prolonged arcing and without danger of short-circuiting adjacent equipment. In the preferred embodiment of my invention, the structural elements are entirely protected from the weather and such parts as might be exposed to ice formation are all subiected to either a torsional or a tension stress during the operation of the switch. This assures satisfactory operation under even the most adverse possible conditions. In addition, the structure of my invention is comparatively simple and is relatively inexpensive to manufacture.

It is my belief that the principal novelty of my invention resides in the combination of cooperating elements which have been particularly pointed out in the appended claims. It is my intention that the language of these claims should be accorded the broadest reasonable construction, and that my invention should be limited only by what is expressly stated therein and by the prior art.

I claim as my invention:

1. In a circuit interrupter; a pair of spaced conducting members; a swingable means adapted to bridge said conducting members when said interrupter is in the closed-circuit position so as to provide an electrical circuit therebetween; said swingable bridging means comprising conducting means and a tubular means fordeflning an arc passage wherein said conducting means is adapted to move, at least a portion of said tube being lined with a material that is capable of evolving an arc extinguishing gas when placed in proximity to an electric arc; and actuating means for said interrupter including means for moving said conducting means through said arc passage and means for swinging said tube to the open and to the closed circuit position.

2. In a circuit interrupter; a pair of spaced conducting members; a swingable means adapted to bridge said conducting members when said interrupter is in closed circuit position so as to provide an electrical circuit therebetween; said swingable bridging means comprising conducting means and a tubular means for defining an arc passage wherein said conducting means is adapted to move, the cross-sectional area and outline of said conducting means being substantially the same as the cross-sectional area and outline of said tubular passage in order that said conducting means shall substantially close one end of said tube during the are drawing operation, the other end of said tube being open during the circuitopening operation; at least a portion of said tube being lined with a material that is capable of evolving an arc extinguishing gas when placed in proximity to an electric arc; and actuating means for said interrupter, including means for moving said conducting means longitudinally through said passage within said tubular means to cause the are which is formed incident to the opening of the circuit controlled by said interrupter to be drawn therein, and means for swinging said bridging means during the circuit-opening operation so as to cause an air gap to exist in the electrical circuit through said interrupter when said interrupter is in the open-circuit position, the gas evolved from said lining flowing longitudinally through said are passage toward the open end thereof to extinguish the are drawn therein by said movable conducting means.

3. In a circuit interrupter a pair of spaced contacts; a movable bridging means for electrically connecting said contacts when said interrupter is in the closed-circuit position; and actuating means for said interrupter; said bridging means including a tube, which is formed at least partially of insulating material and which is swingable into and out of engagement with at least one of said spaced contacts, and a conducting means movable through the passage within said tube during the operation of said interrupter; said actuating means, during the circuit-opening operation, causing said conducting means to move in said passage to establish the are which is formed incident to the opening of the circuit controlled by said interrupter therewithin, and also swinging said tube out of engagement with at least one of said contacts to introduce an air break into the electrical circuit of said switch.

4. In an expulsion-type circuit interrupter; a pair of spaced conducting means; a movable bridging means for electrically connecting said conducting means when said interrupter is in the closed-circuit position; and actuating means for said interrupter; said bridging means including a swingably supported tube, at least a portion of which is lined with a solid material capable of evolving an arc extinguishing gas when placed in proximity to an electric arc, and a conducting means movable through the passage within said tube during the operation of said interrupter; said actuating means, during the circuit-opening operation, causing said conducting means to move through said passage to establish the are which is formed incident to the opening of the circuit controlled by said interrupter therewithin, and also swinging said tube away from the normal .closed-circuit position to efiect a lengthening of the arc and to direct the,

outward flowing gases evolved from said lining away from said spaced conducting means.

5. In an expulsion-type circuit interrupter; a pair of spaced conducting means, a movable bridging means for electrically connecting said conducting means when said interrupter is in the closed-circuit position; and actuating means for said interrupter; said bridging means including a swingably supported tube at least partially of insulating material, and a conducting means movable through the passage within said tube during the operation of said interrupter; said actuating means including a pair of springs which are charged during the operation of said interrupter; one of said springs, during the circuit-opening operation; causing said conducting means to move through said passage at high speed to establish the arc which is formed incident to the opening of the circuit controlled by said interrupter therewithin; and the other or" said springs, during the circuit-opening operation, causing said tube to swingaway from the normal closed-circuit position to introduce an air break into the electrical circuit of said switch.

6. In an expulsion-type circuit interrupter; a pair of spaced conducting means; a movable bridging means for electrically connecting said conducting means when said interrupter is in the closed-circuit position; and actuating means for said interrupter; said bridging means including a swingably supported tube at least partially of insulating material, and a conducting means movable through the passage within said tube during the operation of said interrupter; said actuating means, during the circuit-opening operation, causing said conducting means to move through said passage to establish an arc therein, and also swinging said tube away from the normal closed-circuit position to effect a substantial lengthening of said arc; said movable conducting means being flexible in order that said tube may be swung while said conducting means is being moved therethrough.

'7. In a circuit interrupter; a pair of spaced conducting members, a means, swingable between two extreme positions, for bridging said conducting members; and an actuating means for said interrupter; said swingable means including means for defining the walls of a tubular arc passage having a length substantially equal to the distance separating said conducting members, and flexible conducting means movable through said passage to open and to close the electrical circuit through said interrupter; said actuating means including a rotatable insulator, a drum means upon which said flexible conducting means is wound during the operation of said interrupter, means intermediate said rotatable insulator and said drum means whereby the rotation of said insulator is transmitted to said drum, and other means whereby the rotation of said insulator causes said tubular means to swing from one extreme position to the other,

8. In a circuit interrupter; a pair of spaced stationary insulator columns, a rotatable insulator column; conducting means mounted on each of said stationary insulator columns, a means, swingable between two positions, which is adapted to bridge said conducting means when said interrupter is in the closed-circuit position so as to provide an electrical circuit therebetween; said swingable bridging means comprising means for defining the walls of a tubular arc passage having a length substantially equal to the distance separating said conducting members, and flexible conducting means movable through said passage to open and to close the electrical circuit through said interrupter; said actuating means including a drum means upon which said flexible conducting means is wound and from which said flexible conducting means is unwound'during the operation of said interrupter, spring means associated with said drum means, and means whereby the rotation of said rotatable insulator, during the circuit-opening operation first charges said spring and then releases the energy stored therein so as to cause said drum to rotate in such manner that said conducting means is moved through said are passage at high speed.

9. In a circuit interrupter; a pair of spaced stationary insulator columns; a rotatable insulator column; conducting means mounted on each of said stationary insulator columns; a means, swingable between two positions, which is adapted to bridge said conducting means when said interrupter is in the closed-circuit position so as to provide an electrical circuit therebetween, said swingable bridging means comprising means for defining the walls of a tubular arc passage having a length substantially equal to the distance separating said conducting members, and flexible conducting means movable through said passage to open and to close the electrical circuit through said interrupter; at least a portion of said tubular arc passage beinglined with a solid material that is capable of evolving an arc extinguishing gas when placed in proximity to an electric arc; said actuating means including a drum means upon which said flexible conducting means is wound and from which said flexible conducting means is unwound during the operation of said interrupter, spring means associated with said drum, means, and means whereby the rotation of said rotatabl insulator during the circuitopening operation first charges said spring and then releases the energy stored therein so as to cause said conducting means to be moved through said are passage at high speed.

10. In a circuit interrupter; a pair of spaced stationary insulator columns; a rotatable insulator column; a contact mounted on each of said stationary insulator columns; a movable means adapted to bridge said contacts when said interrupter is in the closed-circuit position so as to provide an electrical circuit therebetween; said movable bridging means comprising conducting means, and a tubular means for defining an arc passage wherein said conducting means is adapted to move; and actuating means for said interrupter including means operable in response to the rotation of said rotatable insulator column to cause said conducting means to move through said tubular means to draw an arc therein and to then cause said tubular means to move out of engagement with at least one of said contacts so as to cause an air gap to exist in th electrical circuit through said interrupter when said interrupter is in the open-circuit position.

11. In a circuit interrupter, a pair of spaced stationary insulator columns; a rotatable insulator column; conducting means mounted on each of said stationary insulator columns; a swingable blade means adapted to bridge said conducting means when said interrupter is in the closed-circuit position; means of considerably greater arc interrupting capacity than said swingable blade means for extinguishing the arcs which are formed incident to the opening of the circuit controlled by said interrupter; said second interrupting means comprising conducting means, and a tubular means for defining an arc passage wherein said conducting means is adapted to move; and actuating means for said interrupter including means operable in response to the rotation of said rotatable insulator column to cause said blade means to swing to the opencircuit position, to cause said conducting means to move through said tubular means, in order that the circuit shall be opened by said second interrupting means during each operation of said interrupter, and to swing said tubular means out of engagement with at least one of said conducting means.

12. In a circuit interrupter; a pair of spaced stationary insulator columns; a rotatable insulator column; conducting means mounted on each of said stationary insulator columns; a swingable blade means adapted to bridge said conducting means when said interrupter is in the closed-circuit position; means of considerably greater arc interrupting capacity than said swingable blade means for extinguishing the arcs which are formed incident to the opening of the circuit controlled by said interrupter; said second interrupting means comprising conducting means, and a tubular means for defining an arc passage wherein said conducting means is adapted to move; and actuating means for said interrupter including means operable in response to the rotation of said rotatable insulator column to cause said blade means to swing to the opencircuit position, to cause said conducting means to move through said tubular means in order that the circuit shall be opened during each operation of said interrupter by said second interrupting means, and to swing said tubular means out of engagement with at least one of said conducting means in order that an air gap may exist in the electrical circuit through said interrupter when said interrupter is in the open circuit position.

13. In a circuit interrupter; a pair of spaced stationary insulator columns; a rotatable insulator column; conducting means mounted on each of said stationary columns; a swingable blade means adapted to bridge said conducting means when said interrupter is in the closed-circuit position; means of considerably greater are interrupting capacity than said swingable blade means for extinguishing the arcs which are formed incident to the opening of the circuit controlled by said interrupter; said interrupting means comprising conducting means and a tubular means for defining an arc passage wherein said conducting means is adapted to move, at least a portion of the inner surface of said tubular means being lined with a material that is capable of evolving an arc extinguishing gas when placed in proximity to an electric are; said conducting means being so proportioned that said are passage is substantially closed thereby, the opposite end of 'said are passage being open during the circuit interrupting operation; and actuating means for said interrupter, including means operable in response to the rotation of said rotatable insulator column to cause said conducting means to move through said tubular means to draw an arc therein; said are causing the evolution of considerable quantities of gas from the lined portion of said are passage, which gas flows longitudinally through said passage with an expulsive action to effect the extinguishing of said are.

14. In a circuit interrupter; a pair of spaced stationary insulator columns; a rotatable insulator column; conducting means mounted on each of said stationary insulator columns; a swingable blade means adapted to bridge said conducting means when said interrupter is in the closedcircuit position; means of considerably greater are interrupting capacity than said swingable blade means for extinguishing the arcs which are formed incident to the opening of the circuit controlled by said interrupter; said second interrupting means comprising conducting means and a tubular means for defining a passage wherein said conducting means is adapted to move; and actuating means for said interrupter including means operable in response to the rotation of said rotatable insulator column to cause said blade means to be swung to the open-circuit position, and to cause said conducting means to move through said tubular means in order that the circuit shall be finally opened, during each operation of said interrupter, by said second interrupting means; said actuating means including a drum means upon which said flexible conducting means is wound and from which said flexible conducting means is unwound during the operation of said interrupter.

15. In a circuit interrupter; a pair of spaced contacts; a movable blade means which is adapted to bridge said contacts when said interrupter is in the closed circuit position; means of considerably greater are interrupting capacity than said blade means, said second interrupting means being electrically connected in parallel with said blade at least during each opening operation of said interrupter, and comprising conducting means and a tubular means for defining an arc passage wherein said conducting means is adapted to move; and actuating means for said interrupter, including means operable during each circuit opening operating to cause said blade means to move to the open circuit position, to positively move said conducting means through said tubular means in order that the circuit through said interrupter shall be opened by said second interrupting means during each operation thereof, and to move said tubular means out of engagement with at least one of said contacts in order that a visible air gap may exist in the electrical circuit through said interrupter when that device is in the open circuit position.

16. In a circuit interrupter; a pair of spaced, stationary insulator columns; conducting means mounted on each of said stationary insulator columns; a swingable blade means adapted to bridge said conducting means when said interrupter is in the closed circuit position; means of considerably greater arc interrupting capacity than said swingable blade means for extinguishing the are which is formed incident to the opening of the circuit controlled by said interrupter, said second interrupting means including a swingably supported tube, at least a portion of which is lined with a solid material capable of evolving an arc extinguishing gas when placed in proximity to an electric arc, for defining the walls of an arc passage, and a conducting means movable through said are passage during the operation of said interrupter; and actuating means for said interrupter, including means operable during each 'circuit opening operation to cause said blade means to swing to the open circuit position, to cause said conducting means to move through said are passage to establish the arc which" is formed incident to the opening of the circuit controlled by said interrupter therewithin, and to swing said tube away from the normal closed circuit position to efiect the lengthening of the arc and to direct the outwardly flowing gases evolved from said lining away from said conducting means.

17. In a circuit interrupter; a pair of spaced stationary insulator columns; conducting means mounted on each of said stationary insulator columns; a swingable blade means adapted to bridge said conducting means when said interrupter is in the closed circuit position; means of considerably greater are interrupting capacity than said swingable blade means for extinguishing the are which is formed incident to the opening of the circuit controlled by said interrupter, said second interrupting means including a swingably supported tube, formed at least partially of insulat ing material, for defining the walls of an arc passage, and a conducting means movable longitu dinally through said are passage during the operation of said interrupter; and actuating means for said interrupter, including means operable during each circuit opening operation to cause said blade means to be swung to the open circuit position, to cause said conducting means to move through said passage to establish an arc therein, and to swing said tube away from the normal closed circuit position to effect a substantial lengthening of said arc, said conducting means movable through said are passage being flexible in order that said tube may be swung while said conducting means is being moved longitudinally therethrough.

18. In an electric switch; a contact; a cooperat ing blade, which normally carries at least the greater portion of the current flowing through said switch, supported for swingable movement into and out of engagement with said contact; a circuit interrupting means of substantially greater arc extinguishing capacity than said blade, said means being electrically connected in parallel with said blade at least during each opening operation of said switch, and including a tube, which defines the walls of an arc passage and which is supported for swingable movement into and out of engagement with said contact, and means for establishing the arc incident to the opening operation of said switch within said passage; and actuating means for said switch operable during each opening operation of said switch first to swing said blade out of engagement with said contact and then to swing said tube out of engagement with said contact.

19. In a circuit interrupter; a contact; a cooperating blade, which normally carries at least the greater portion of the current flowing through said switch, supported for movement into and out of engagement with said contact; a circuit interrupting means of considerably greater arc extinguishing capacity than said blade, said means being electrically connected in parallel with said blade at least during each opening operation of said switch, and including a movably supported tube, which defines the walls of an arc passage, and means for establishing the arc incident to the opening operation of said switch within said passage; at least a portion of said tube being lined with a solid material capable of evolving an arc extinguishing gas when placed in proximity to an electric arc and said tube being movable into and out of engagement with said contact; and actuating means for said switch operable during each opening operation of said switch first to move said blade out of engagement with said contact and then to move said tube out of engagement with said contact to provide a visible air gap between said contact and said blade and tube.

20. In an electric switch; a pair of spaced, stationary insulator columns; a contact mounted on each of said columns; a blade, which normally carries at least the greater portion of the current fiowing through said switch, supported for swingable movement from a normal open circuit position to a position where it bridges said contacts; a circuit interrupting means of greater are extinguishing capacity than said blade which is adapted to provide an electrical circuit between said spaced contacts at least during each opening operation of said switch, said last-mentioned circuit interrupting means including a swingably supported tube which defines the walls of an arc passage, at least one end of which is open during each operation of said means, and conducting means movable through said arc passage to establish the arc incident to each opening opera tion of said switch therewithin; said tubular means being swingable into and out of engagement with at least one of said contacts and at least a portion thereof being lined with a material which is capable of evolving an are extinguishing gas when brought into proximity with an electric arc; and actuating means for said switch so arranged that during each opening operation of said switch said blade means is moved out of engagement with at least one of said con tacts a predetermined distance before said tube is moved any substantial distance, and then said tube is moved out of engagement with at least one of said contacts.

21. In a load break disconnect device, a pair of terminals, a movable blade member for bridging said terminals, an arc extinguisher having an arc passage and conducting means therethrough, said conducting means being normally connected in parallel with said blade member across said terminals and movable for establishing an are within said passage and to make and break the circuit between said terminals, an actuating means for said blade member and for said conducting means operative for moving said blade member out of engagement with at least one of said terminals prior to causing said conducting means to be moved to open circuit position, said blade member, are extinguisher and conducting means when actuated to the open position being visibly separated from at least one of said terminals a distance sumcient to withstand line voltage.

22. In a load break disconnect device, a pair of terminals, a movable blade member for bridging said terminals, conducting means connected across said terminals normally paralleling said blade member, said conducting means including a contact member, an arc extinguishing housing surrounding said contact member, said contact member being movable within said housing to open and closed positions to respectively interrupt and establish the circuit between said terminals, and actuating means for said blade member and said contact member operative for moving said blade member out 01' engagement with at least one of said terminals prior to causing said contact member to be moved to the open circuit position, said blade and said are extinguishing housing including said contact member when in the open position being separated a substantial distance from all conducting parts of at least one of said terminals to provide an air gap sufllcient to withstand high voltage.

23. The combination with a switch having a contact and a blade member operable into and out of engagement with said contact of an arc extinguishing device having an arc chamber, conducting means ior normally establishing a circuit through said are extinguishing device in parallel with said blade member, said conducting means including a contact 'member movable within said arc chamber to open and closed positions, and joint means operative to disengage said blade member from said contact prior to actuating said contact member to open circuit position and to cause a separation in air of said blade member, are extinguishing device including said contact member and switch contact sumcient to withstand high voltage.

24. In an electric switch, a contact, a cooperating blade for normally carrying the greater portion of the current flowing through said switch, means for supporting said blade for swingable movement into and out of engagement with said contact, a-circuit interrupting means of substantially greater are extinguishing capac-- ity than said blade, said circuit interrupting means being electrically connected in parallel with said blade at least during each opening operation of said switch and including a tube defining the walls of an arc passage, a contact member movable within said tube for establishing and breaking the circuit through said circuit interrupting means, and actuating means for said switch first to swing said blade out of engagement with said contact and then to move said contact member to the circuit interrupting position, and finally to introduce a visible air gap between said blade, tube and contact member and said contact 01 lengths sufllcient to withstand high electrical tension.

HERBERT J. CRABBS.

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