US2816981A - Circuit interrupter construction - Google Patents

Description

Dec. 17, 1957 s. 1. LINDELL CIRCUIT INTERRUPTER CONSTRQCTION 3 Sheets-Sheet 1 Filed March 6, l956 INVENTOR. figgardZZL/Zdfl, BY

Dec. 17, 1957 s, DEL 2,816,981

CIRCUIT INTERRUPTER CONSTRUCTION IN VEN TOR.

Dem 771- s. 1. LINDELL 2,816,981

cmcun INTERRUPTER CONSTRUCTION Filed March e. 1956 3 Sheets-Sheet 3 74492335 flj/ 60 United States Patent CIRCUIT INTERRUPTER CONSTRUCTION Sigurd I. Lindell, Chicago, 11]., assignor to S & C Electric Company, Chicago, Ill., a corporation of Delaware Application March 6, 1956, Serial No. 569,909

20 Claims. (Cl. 200-114) This invention relates, generally, to circuit interrupters and it has particular relation to such devices for operation in conjunction with disconnecting fuses, disconnecting switches and the like for opening them under load without drawing an external arc. This invention is an improvement over the inventions of Lindell Patent Nos. 2,671,142 and 2,671,145, both issued March 2, 1954, and Lindell application Serial Nos. 412,182, filed February 24, 1954, and 493,083, filed March 9, 1955.

Among the objects of this invention are: To provide an improved circuit interrupter for opening under load disconnecting fuses, disconnecting switches and the like without the formation of an unconfined arc; to provide for random location of one of the separable contacts of the interrupter with respect to its cooperating contact; to mount the one separable contact and the associated trailer, spring and cable assembly and conducting rod for free rotation about the longitudinal axis of the interrupter; to protect the inner surface of the inner insulating sleeve from the heat of the are that is drawn when the contacts separate under load; to facilitate the escape of the products of the arc by increasing the nun1- ber of escape passageways and placing them close to the arc; to limit the extent that the inner sleeve can be withdrawn from the outer tubular insulating housing; to employ an insulating key for guiding the sleeve in its move ment through the housing; to secure a metallic sleeve end insert to one end of the sleeve and a sleeve terminal to the other end of the sleeve by interfitting tapered joints held together by cement; to counterbalance the circuit interrupter when the inner sleeve is withdrawn to the maximum permissible extent from the insulating housing; to enclose the counterbalancing mechanism within the conducting arm which extends from and is movable with the inner sleeve; to employ a spring pressed plunger cooperating with a cam on a strut pivot shaft to provide the counterbalancing action and to limit the movement of the plunger; and to bias the keeper by means of a spring pressed plunger completely enclosed in the strut for returning it to a central position with respect to prong adapted to engage a current carrying member of the device that is to be opened under load without external arcing.

Other objects of this invention will, in part, be obvious and in part appear hereinafter.

This invention is disclosed in the embodiment thereof shown in the accompanying draWins and it comprises the features of construction, combination of elements and arrangement of parts that will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the appended claims.

For a more complete understanding of the nature and scope of this invention reference can be had to the following detailed description, taken together with the accompanying drawings, in which:

Figure 1- is a perspective view of a circuit isolating 2,816,981 Patented Dec. 1?, 1957 device such as a disconnecting fuse, showing how the auxiliary circuit interrupter of the present invention can be applied thereto, the particular circuit isolating device being that disclosed in Lindell application Serial No. 435,747, filed June 10, 1954, now Patent No. 2,745,921 issued May 15, 1956, and assigned to the assignee of this application;

Figure 2A is a vertical sectional view, at an enlarged scale, of the upper portion of the auxiliary circuit interrupter shown in Figure 1;

Figure 2B is a vertical sectional view, at an enlarged scale, of the lower portion of the auxiliary circuit interrupter shown in Figure 1, the arrangement being such that when Figure 2B is placed below Figure 2A and in alignment therewith a longitudinal cross-sectional view of the complete auxiliary circuit interrupter is provided;

Figure 3 is a horizontal sectional view taken generally along the line 33 of Figure 2B;

Figure 4 is a view, in side elevation, of the inner contact sleeve;

Figure 5 is a vertical sectional view taken generally along the line 5-5 of Figure 2B; and

Figure 6 is a vertical sectional view taken generally along the line 66 of Figure 2A.

Referring now particularly to Figure 1 of the drawings, it will be observed that the reference character 10 designates, generally, a circuit isolating device of the disconnecting fuse type. As pointed out hereinbefore, the de tails of construction of the circuit isolating device 10 are set forth in Lindell application Serial No. 435,747, filed June 10, 1954. Accordingly, only a general description of this device will be set forth here. While particular reference is made to a disconnecting fuse device, it will be understood that the present invention can be employed where the fuse tube of the disconnecting fuse is replaced by a metallic conducting tube or it can be used in conjunction with a disconnecting switch that is modified suitably for use in conjunction with the auxiliary circuit interrupter mounted on a live line stick as described hereinafter.

The circuit isolating device or disconnecting fuse 10 includes an insulator 11 which is arranged to be stationarily mounted on a cross arm or the like and has a lower terminal contact member 12 carrying a connector 13 for connection to a line terminal. Pivoted at 14 on the lower contact member 12 is a lower current carrying member 15 that is positioned at the lower end of a fuse tube 16. At its upper end the fuse tube 16 has an upper current carrying member 17 which is positioned in contact engagement with a normally energized con tact member 18 carried by the upper end of the insulator 11. In order to remove the upper current carrying member 17 from contact engagement with the terminal contact member 18, the former is provided with an eye or pull ring 19 of conducting material for receiving the prong of a live line tool. In accordance with conventional practice, the fuse tube 16 is manipulated by inserting the prong of the live line tool in the eye or pull ring 19 for swinging the upper current carrying member 17 into or out of contact engagement with the terminal contact member 13.

For urposes more fully disclosed in Lindell application Serial No. 435,747, filed June 10, 1954, the terminal contact member 18 includes an L-shaped reinforcing bar 20 having a downwardly extending arm 21 which carries a guide 22. The guide 22 is employed, in part, for guiding the upper current carrying member into proper contact engagement with the terminal contact member 18. The guide 22 includes forwardly extending arms 23 at the outer ends of which are transversely extending horns or studs 24. Provision is made for connecting the energized line con ductor to the terminal contact member 18 through a terminal pad 25. It will be understood that the upper portion of the terminal pad (not shown) carries a connector or like device to facilitate connection of the energized line conductor thereto.

It is often necessary to open the circuit isolating device or disconnecting fuse 10 while it is carrying loadcurrent. When such operation is performed, an arc is drawn between the upper current carrying member 17 and the terminal contact member 18 which is likely to damage the parts which are contacted by the arc and also, where other circuits are involved, is likely to fault one or more circuits in the event that the arc is drawn and should jump to another circuit or the ground. Also there is the likelihood of injury to the operator. invention, provision is made for safely and expeditiously opening the circuitisolating device llll while it is carrying line current. It is for this purpose that an auxiliary circuit interrupter, shown generally at. 27, is employed.

It will be observed that the auxiliary circuit interrupter 27 is provided near its upper end with an eye' member or pull ring that is shown generally at 28-. The eye member or pull ring 28 includes a bow shaped contact member 29, Figure 2A, which had oppositely extending trunnions' 30 that arerockably mounted by parallel end portions 31 of a pair of arms 32 that are formed integrally with and extend radially from a pull ring 33. It will be understood that the bow shaped contact member 29, as shown in Figure 1, is positioned over one of the horns or studs 24 for connection to the normally energized terminal contact member 18- of the circuit isolating device 10. In addition, this connection: is both an electrical and a mechanical connection and serves as an anchor for resisting an endwise' pull applied to the auxiliary circuit interrupter 27, in a manner to be described, not only for operating the fuse tube 16 tothe open position but also for subsequently operatingthe' auxiliary circuit interrupter 27 to interrupt the flow of load current therethroug'hwithout causing an unconfined arc.

Connection to. the upper current carrying member 17 is provided by contact means 34 in the form of a pin or prong that is carried by a support member 35 in the form of a strut, preferably formed of aluminum, on which the auxiliary circuit interrupter 27 is flexibly mounted by a universal joint that is indicated, generally, at 36 in Figures 1 and 2B of the drawings. The support member or strut 35 has an. integral extension 37 provided with a claw bracket 38 that can be secured-by a clamp screw 39 to a similar claw bracket 40 which is formed integrally with a fitting 41 that is arranged to be carried by one end of a live line stick a ortion which is shown at 42 in Figure 1-.

In orderv to insure that the pin or prong 34- remains in engagement with the eye or pull ring 19, which constitutes an integral extension of the upper currentcarrying member 17, a rotary keeper 43 is employed which, as will appear hereinafter, is mounted to swing about two axes that are right angles to each other in order to permit entry of the pin or prong 34 into the eye or pull ring 19 and for holding the same in operative position therein.

Referring now to the upper portion of Figure 2A of the drawings, it will be observed that the pull ring 33 is keyed at 46- to a pull ring bushing 47 which is cemented onto the upper end of a tubular insulating housing 48 that is formed of a phenolic condensation product or the like which is capable of providing the desired insulating qualities and is mechanically strong. The pull ring 33' telescopes over the bushing 47 and is held in position thereon, in part by the key 46 and in part by a crescent snap ring 49. It will be understood that the pull ring 33 and bushing 4'7 form a part of a stationary contact assembly at the upper end of the tubular insulating housing 48' and-such assembly is designated, generally, by the reference character 50. The arrangement and construction of the pull ring 33 and bushing 47 whereby the latter is removably mounted on the In accordance with the present 4 former are disclosed and claimed in application Serial No. 571,472, filed March 14, 1956.

Included with the stationary contact assembly 50 is an end cap 51 that is threaded into the upper end of the pull ring bushing 47. The end cap 51 is provided centrally with a depending hollow boss 52 having an upwardly facing annular shoulder 53 for cooperating with a shouldered retaining nut 54 for receiving the threaded upper end 55 of a rigid conductor rod 56. A lock nut 57, threaded on the upper end 55, has snug fitting engagement with the lower end of the retaining nut 54 with the latter projecting slightly below the lower surface of the boss 52 so that a clearance 58. is providedv between it and the upper surface of the lock nut 57. A set screw 59 secures the conductor rod 56 in position in the retaining nut 54. This construction permits the rigid conductor rod 56 to rotate about its longitudinal axis with respect to the end cap 51 and thus permits the random positioning of an arcing contact (to be described hereinafter) carried by the conductor rod 56 with respect to a cooperating arcing contact.

At the lower end of the conductor rod 56 is a cam ter' minal 61 which is provided with a conically shaped shoulder 62 and an upwardly facing annular stop shoulder 63. The purposes of these shoulders will be described present 1y.

Referring now to Figure 2B of the drawings, it will be observed that the lower portion of the cam terminal 61 has a spring and cable assembly connected thereto. comprising a coil tension spring 64 and a flexible conductor or cable 65. At their lower ends they are connected to the upper end of a movable first arcing contact 68 which is generally cylindrical in cross section and to which a trailer 69 of gas evolving material is connected by a trailer stud 70. The construction of the trailer 69 and stud 70 is described in more detail in Mikos application Serial No. 545,044, filed November 4, 1955, and assigned to the assignee of this application.

Threaded onto and movable with the first arcing contact 68 isa tubular metallic sleeve 71 which extends upwardly through the tubular insulating housing 48 to a position below the contact assembly 50. A stop ring 72' is carried by the upper end of the metallic sleeve 71, as shown in Figure 2A of the drawings, and extends around its inner surface. The stop ring 72 is provided for engaging the stop shoulder 63 on the cam terminal 61 under certain conditions. If the first arcing contact 68 should be prevented by friction or otherwise from disengaging its cooperating contact 110 despite the tension applied by the spring 64, then continued downward movement of the inner sleeve 77 after engagement of the stop shoulder 63- by the stop ring 72 and arresting of further movement of the first arcing contact 68 will break loose the second arcing contact 110' and permit the spring 64 to function in its intended manner. In the event that the spring 64 should fail for some reason, the contacts 68 and 110 will be separated a substantial distance, for example, about half the break distance that results when the spring 64 is able to function normally.

With a view to moving the tubular metallic sleeve 71 downwardly for stressing the spring 64 a trigger or latch 73 is pivotally mounted at 74 on a trigger frame 75 which is secured to a metallic inner sleeve end insert 76 that is carried by the upper end of an inner insulating sleeve 77 that is formed of a material, such as phenolic condensation product, that is capable of providing thedesired insulation and in addition has suitable mechanical properties.

It will be observed that the metallic inner sleeve end insert 76 has a portion 78 that telescopes with the upper end portions 79 of the sleeve 77 and that these portions are. tapered. A layer 80 of suitable cement between theoverlapping portions 78 and.79 serves-to hold the insert.

76 firmly in place on the inner insulating sleeve 77 and provides a maximum of. strength with a minimum of combined cross section. Further, this arrangement provides the maximum attainable cross section at each end of the sleeve 77 with substantially the same inside and outside diameter at the ends of each point.

It will be understood that, when the inner insulating sleeve 77 is moved downwardly, it carries with it the trigger or latch 73 the lower end 81 of which engages the upper end of the metallic sleeve 71 and thus causes it and the arcing contact 68 to move downwardly through the tubular insulating housing 48 until the lower end 81 of the trigger or latch 73 engages the shoulder 62 whereupon a slight further downward movement displaces the trigger 73 from engagement with the metallic sleeve 71 and permits the same and the arcing contact 68, together with the trailer 69, to move upwardly under the influence of the spring 64 for interrupting the circuit in a manner to be described in more detail hereinafter.

It is desirable that the inner insulating sleeve 77 be freely movable longitudinally in the tubular insulating housing 48 but that it be prevented from rotating about its longitudinal axis with respect thereto. Accordingly, a slot 83 is provided in the outer surface of the inner insulating sleeve 77 longitudinally thereof for receiving a tongue or pin 84 that is formed integrally with a ring 85 which is cemented, as shown in Figure 2B, to the inner surface of the tubular insulating housing 48. Preferably the tongue or pin 84 and ring 85 are formed of insulation in order to reduce the likelihood of flashover of the auxiliary circuit interrupter 27 either externally or internally after the circuit has been opened therethrough.

The ring 85 serves as a stop to engage the under side of the trigger frame 75 and limit the outward movement of the inner sleeve 77. The shock incident thereto is transmitted to the tapered cemented joints at the ends of the sleeve 77.

In order to limit the upward movement of the metallic sleeve 71 after the trigger 73 has been tripped, a stop ring 86 is secured to the metallic sleeve 71 and is arranged to engage the underside of a stop ring 87 that is formed preferably of insulating material and is cemented into the sleeve end insert 76 at the upper end of the inner insulating sleeve 77.

The arc which is drawn on movement of the arcing contact 68 upwardly is extinguished by the cooperation of the trailer 69 and the inner surface of a liner 88 that is formed of a material which evolves an arc extinguishing medium when subjected to the heat of an arc. Grooves 89 and 90, Figures 2A and 2B, are provided in the liner 88 near its ends for receiving 0 rings 91 and 92. The purpose of this construction is to provide a gas tight seal between the outer surface of the liner 88 and the inner surface of the insulating sleeve 77 that is coextensive therewith.

Cooperating with the arcing contact 68 is a movable contact assembly that is indicated, generally, at 95 and located at the lower end of the inner insulating sleeve 77 in Figure 2B of the drawings. The movable contact assembly 95 includes a contact sleeve terminal 96 which has a portion 97 that telescopes with the lower portion 98 of the insulating sleeve 77. It will be observed that the portions 97 and 98, like the portions 78 and 79 at the upper end of the insulating sleeve 77, are tapered and that a layer 99 of cement is employed to secure the contact sleeve 96 to the lower end of the insulating sleeve 77. This construction, like the construction at the upper end, provides sufiicient strength for resisting mechanical shocks to which the insulating sleeve 77 and associated parts are subjected, particularly when the auxiliary circuit interrupter 27 is operated by impact movement of the live line stick 42 until the trigger frame 75 engages the ring 85 to arrest such movement as described above.

The contact sleeve terminal 96 has a depending extennets of the are that are drawn when the device operates.

Radial vents 102 are located around the periphery of the extension 100 and communicate with the chamber 101 for placing the same in communication with the atmosphere when the inner insulating sleeve 77 is withdrawn from the tubular insulating housing 48. At its lower end the extension 100 has a hollow light transmitting plug 103 threaded therein. It is provided with radial vents 104 to permit discharge of the are products to the atmosphere. Within the hollow plug 103 is a screen 105 that is cup-like and overlies the vents 102 and 104. It is provided for preventing the discharge of solid particles through the vents.

Within the contact sleeve terminal 96 is an inner contact sleeve 106, Figure 4, which is provided with a radial opening 107 for receiving a contact locating screw 108 that is held in place by a set screw 109. Extending upwardly from and formed integrally with the inner contact sleeve 106 are flexible contact fingers 110 which, as shown in Figure 2B of the drawings, are arranged to engage the outer surface of the first arcing contact. It will be understood that the flexible contact fingers 110 constitute a second arcing contact and that it is between these arcing contacts that the arc is drawn on operation of the auxiliary circuit interrupter 27. A generally cylindrical contact spring 111 cooperates with the contact fingers 110 to urge them into contact engagement with the outer surface of the first arcing contact 68.

With a view to facilitating the escape of the gas generated on separation of the arcing contacts 68 and 110, longitudinally extending slots 112 are provided between the contact fingers 110 as shown in Figures 2B, 3 and 4 of the drawings. The flow of gas incident to the separation of the arcing contacts then can take place outwardly through these slots 112 and through radial vents 113 which are located in the contact sleeve terminal 96. It will be observed that the vents 113 are coextensive with the lower ends of the slots 112 and that they are uncovered when the insulating sleeve 77 is withdrawn from the tubular insulating housing 48. Also, some of the gas flows over the upper ends of the contact fingers 110 and downwardly through the annular space between them, the sleeve 77 and the contact sleeve terminal 96 to the vents 113.

A substantial amount of heat is generated when the are is drawn between the arcing contacts 68 and 110. In order to prevent damage to the surrounding inner surface of the inner insulating sleeve 77 an arc shield 114 is secured to the latter by cement. As shown the arc shield 114, which is formed preferably of an arc resisting material such as stainless steel or a refractory material, is coextensive with the lower end of the liner 88 and the upper ends of the flexible contact fingers 110.

Near its lower end the tubular insulating housing 48 is provided with a longitudinally extending slot 115 through which a conducting arm 116 projects and extends along the housing 48 toward its upper end. It will be observed that the contact locating screw 108 and set screw 109 are located in the lower end of the conducting arm 116.

The universal joint 36, previously referred to, is located at the upper end of the conducting arm 116. For this purpose there is provided a socket 117 the axis of which is along the longitudinal axis of the conducting arm 116. Bearings 118 and 119 are formed integrally with the arm 116 on opposite sides of the socket 117 with the axis thereof at right angles to the longitudinal axis of the socket. Slidably mounted in the socket 117 is a spring plunger 120 having a flat head 121 the periphery of which has a sliding fit in and is guided by the counter bored upper portion of the socket 117. The lower end of the spring plunger 120 extends into a reduced diameter bore 122 at the base of the socket 117 and is guided thereby for movement along its longitudinal axis under the influence of a coil compression spring 123 which, as

shoWnin FigureZB, reacts' between thebase ofithe socket 117a'ndthe under'sideofthe fiat 'headllZl. The downward movement of the sprin'g"'plunger"120 is limited by 'theengagement of the un'dertsideof' the fiat head 121 with 'a"slronlder 124. 'The arrangementtis' such'that this engagement takesplace before the "spring 123 is fully compressed. This avoids likelihood of 'injury 'to Tithe spring" whichrnight occur if it were" permitted to go's'olid. It willbe understood'that'the spring 123"is .siifiiciently powerful so "that, in cooperation w'ithithe universal. joint 36,"'itis capable"'of'counterbalancingftheweight of the auxiliarypireuit'interrupter"27 not onlywherr itis in "the collapsed position as shown in Figures 1,"2'A an'd2B'of thedra'Wings, but also whenthe inner insulating sleeve 77 and parts associated therewith'are withdrawn from the tubular insulating housing "48" to'"the' full extent required' for 'fie'ctin'g circuit interruption.

lou'rnaled' inthe' bearings 1'18 and 119 is a "strut pivot shaft 12'5""that' is formed "of'a'n'inner endyportion 126 and'an'outer'end portion12 7. 'These'portio'ns are interconnected by a set screw' I28'that.is held in position by a locking set"screw'129. 'As' shown'in Figure a 'rectangrlar cam 130 is positioned non-'rotatablybn'the strut pivot shaft IZS between the' portions .126' and 127.

Thus;'when the strut pivot shaft isrotate'd' in either direction; thereetangular cam cooperates with the flat'head 121' to depress the spring plunger"128'against the biasing action of the" spring 123. The reaction is such that the's'pring 123'biases the'strut pi'votshaft 125 to the centralpositi'onsho'wn 'inFigureS. This action is employed for centeringthe supporfmernber or strut 35 in amanner to be described presently. The upper end of the'socket 117 above the strut pivot'shaft 125 is close'd 'by apivotcover 131.

Itwill be'observed inFigure 2B of the drawings that the-outer end'portion '127 of the strut pivot shaft'125 projects outwardlybeyond the "bearings '119. It is arranged torece'ive a pivotpin134 on'which the extension 37 of 'thesupport member or strut'35 is rockably mounted. A spring 135 surrounds the pivot pin 134 and reacts between'oneside of the bearing 119' and the underside of the'extension'37 tobias the support member or strut35 in a direction toward the'tubular insulating. housing 48. The movement of the support member or strut 35 under the influence of the 'spring'1'35 is limited by a set screw 136which is threaded into the extension 37 and bears against a wear resisting washer'1'36 formed, forexample, of stainless steel and overlying the bearing 119. A cover plate'137 is secured to the extension 37 by rivets and overlies the outer end of the opening in which the set screw'136 is located.

It is desirable to hoid the inner insulating sleeve77 in extended position after the separable contacts have opened the circuit in order to prevent accidental reclosure of the circuit. For this purpose a latch 138 is provided andis formed of suitable insulating material. At its lower end the latch 138 is rockably mounted on a pivot pin 139 which extends transversely of the conducting arm 116 intermediate the ends of the socket 117 and belowthe strut pivot shaft 125. A spring 140 reacts between the latch 138 and the conducting arm116 to bias the former into'engagement' with the side of the tubular insulating housing '48. When the inner insulating sleeve 77 is withdrawn from the tubular housing 48, the upper end 141 of the latch 138 is rocked by thespring 140 into a posi- 7 tion underneath the lower end 142 of the tubular insulating housing 48 and thus prevents the returnof the inner insulating sleeve '77 until the latch 138 is moved out of locking position.

The'rnanner in which the rotary keeper-43 is rockably mounted" about two axes will now be described with reference to Figure 2A of the drawings. Near Tithe upper endbf the support 'm'e'm'beror strut.3'5' there is provided a boss' 'l45' havinga' 'longitudinaltecess'.146 which extends generallyparall'el tothe supportmember or strnt35 and at rig'htangles to the pin or;prong .34. '..Bearings.147 and "I48.areiformed'integrally with the .boss 145 at the upper'en'd of the longitudinal recess 14'6.in..such position that their axis is at right angles-totthe.longitudinalzaxis of the recess I46. At the'lowerend of. the recess-146 is a keeper plungerguide 149'tl1at is secured .in the..position therein" by a'transverse pin 1 50. .Slidablymounte'd in the opening in the guide 149.is astem 151 of.a keeper plunger I522which is,provided witha. head 153 atits upper end. 'A coil compression spring1154. surrounds the keeper plunger 152and reactslbetweent the underside of the head'153 and the'keeper plunger guide .149 to bias the. keeper plunger. 1'52 upwardly. .-The downward movement of the keeper plunger'l'52iiszlimited by: the engagement of theshoulder .155 On. itsunderside with .the upper end 156 of the guideI149. '.The arrangement is suehthat this engagement takesplacebefore .thespring154 goes solid and thus injury thereto is prevented.

A keeper pivotfshaft-l'57.isjournaled in the bearings 147 and 148 and, as shownv more clearly in Figure 6 of .the drawings, 'it has a flat ..cam surface 158 intermediate its ends whichoverliesthe .upperside of the head 153. It will be understood. that the. spring 154 acting through the keeper plunger.152.cooperateswith the-.fiat cam surface 158 to centerlthe keeper. pivot shaft 157 regardless of the directionin-which itis: rotated from the central .position.

At the outer. end of..the: keeper pivot shaft 157 there is a pivotpin lfilson. which the rotary keeper 4-3 ismounted. The keeper .43. is biased-outwardly. to. the positionshown in Figure 2A of..the.-drawings byrneans-of a-coil compressionspring162 .thatis located in a bore 1'63 of the keeperpivot .shaft..157t and. reactsagainst .a; plunger 164 slidably mounted therein which bears against the inner side of the.keeper .43. .It willube understood that-the keeper 43 is. rotatablexabout thelongitudinal: axis of the keeper pivot..-shaft \157.and ina plane that-.is generally parallel to theplane of.:the.support member. or strut 35. Also the-keeperi43is rotatable about .the pivot pin 161 in a plane at right angles to. its plane of rotation about the axis of the keeper pivot shaft 157. It can be .moved or rocked to the position. shown. by .the broken lines. Thus the keeper I43 can.be rocked inwardly relative to the pin orprong34 and alsoit can. be roekedsideways with respect thereto to facilitate. entryof the pinor prong 34 into the eye or pull ring 19, the'holding of .the pin or'prong 34 within the. pull ring 19 and the removal thereof therefrom.

In orderto maintain contactengagernent with the eye or pull 'ring 19 and. to -preventarcingbetween it and. the pin or prong'i34 a contactfinger, shown generally at 165, is provided. The contact finger 165' includes a conducting sleeve 166 that is secured to one.end 167015 a coil spring the intermediate portion 163 of Which-is positioned around a shaft 169 that. extends transversely. of .the upper end of the supportmemberor strut 35. The otherend 170 of the spring reacts against a wall of the bearing 147 to the end that the contactifinger' 1 65 is biased ina clockwise direction, .as viewed in 'Figure 2A, so that its upper end moves in a. 'slofformed .between walls 171 to a position against'the inside of. a depending flange 172 that is formed integrally withtthe pin or prong 34.

in describing the operation of. the. auxiliarycircnit interrupter 27 it will' be assumed thatthecircuit isolating device 10 is connected in a. line and is carrying current.

The lineman manipulates the livelinestick-tZ carrying the auxiliary circuit interrnpter'ZTuntil.thebow shaped contact member'29 of the eye member. or pull ring 28 overlies one of the horns or studs124. ofthe guide. 22. It is assumed, of course, that the inner insulatingsleevc 77 is positioned entirely within the tubular insulating housing 48 and that. the circuitutherethrough-is.closed with the movable: first arcing. contact 68 inepgagernent with the contact fingers. 110. forming. the second-arcing contact. The circuit from the contact member 18 of the circuit isolating device 10-now extends through the auxiliaryci'rcuit interrupter 27 to the support member'or strut 35 and the ;pin; or-prong'34 carried thereby. Next the auxiliary circuit- =interrupter ;27 is manipulated to position the pin-or prong 34 in the eye or pull ring 19. When the pin or -prong -34 isrintroduced'into the eye or pull ring 19,'--th'e k'eeper43'ismovedinwardly about the pivot pin 161'and*is-rockedtogether with the keeper pivot shaft 157 as may-be required to permit this action. Then the rotary keeper -43is centered by the spring 154 to return to theposition-shown-in Figure 2A of the drawings in alignment-with the pin'or prong 34. At the same time thecontact finger165*engages the eye orpull ring 19 and maintains contact engagement therewith.

The lineman-now-exerts a downward -=pull on the live line stic'k 42. Since the pin or prong 34 is inserted in th'eeyeeor-pullring 19,andsince the bow shaped contact mem-ber-"29 is held stationary by'the horn or stud 24, the inner insulating sleeve 77 is pulled out of thetubular insulating housing 48. This is-accompanied by a movement oftheupper current-"carrying member-17 out of engagementtwith the contact -member'18'. However, no

arc is formed th'erebetweensince these parts are shunted through-the auxiliary; circuit interrupter 27. The trigger or 'latch 73 moves-downwardly withthe sleeve ,7 7 and after-.;-a:slightwmovement-itslowerend 81 engages the ring '72 at theupper-end of the'metallic sleeve 71;

The-continued downward movement of thelive line stick -42 effects afurtherswinging movement of the fuse tube-16-out-of the closed position and afurther withdrawal of the inner insulating sleeve 77 from the tubular insulating housing 48. This is accompanied by an extension of 'the flexible conductor. or-cable 65-and tensioning of the coil spring-64 as a result of the engagement by the lower-end 810i the trigger 73 with the ring 72 at the upperendofthe tubular metallic sleeve 71.

The-ends of: the spring64 are secured against rotation to the-lower-end of the cam terminal 61 and the upper end of th'e iirst-arcing contact 68. As thespring 64 is tensioned on downward movement of the sleeve 77 and 71a torsional-force is created that tends to close its coils and to'rotate the conductor -rod 56 as well as the arcing terminal 68 -with the trailer-69; This torsional force is partly restrained byvthe frictional engagement of the lower end 81 of the trigger-orlatch 73 with the ring 72 at oneendof thespring-64 and-of the retaining nut. 54

sleeve 7I 'together-with the arcing -contact68*upwardly-- through the horeof the liner 88'together with the trailer 69.; An arc is drawnbetween the contact 68-and the contact fingers 110 into the bore of the liner 88 and it is extinguished-byevolution of gas therefrom as wellas by gas from-the outer surface of the trailer 69 which'serves to confine the are as is readily understood. By this time the inner-insulating sleeve 77 will have moved out of the lower endof the tubular insulating housing 48 sufficiently far to uncoverthevents 104,192 and 113. The discharge of thegas generated bythe arc is permitted through these.

vents. The vents 1.13 radially coextensive with the lower ends of the slots E12 between the contact fingers 110 serve to reduce rapidly the gas pressure and avoid undue application of pressure within the lower end of the inner insulating sleeve 77 and-within the contact sleeve terminal 96.5

Another result of-the' release of the trigger or-latch73 'Qmrthe ringw72 isrthe. release of the spring 64 touncoil.

. Whilethespring 64;is;.retrac,ting the firstarcing contact shaped contact member 29 from the horn or stud 24,

68 and until the end of its stroke, the reaction is taken of the nut 54'and good. contact engagement is maintained between it and the' boss 52 of the end cap 51. The torsional force driving the return stroke sets up random rotation of the parts associated with the spring 64 and they assume different positions, particularly at the end of the stroke. Thus the first arcing contact 68 rotates with the trailer 69 and the arc is drawn the next time at a different position with respect thereto and to the liner 88 and the contact fingers 110. Since the metallic sleeve 71 moves with the contact 68, the ring 72 is next engaged at a different location by thelower end 81 of the trigger or latch 73. Thus the wear and erosion onthese parts are distributedjanditheirlives are prolonged.

A-fter theacircuitihas been. opened in the manner. described; thezcontinue'd downwardmovement of the live line tool 42icauses'the latch 138' to engage the lower end 142' of the tubularz'insulating housing 48 with the result that the innerinsulating sleeve 77 is held in the extended position. ASiPDiDtCd out, the spring 123 which forms a part of the universal joint 36 is of suflicient strength to counterbalance-the.auxiliary circuit interrupter 27 in the extendedposition;

Thelineman now manipulates the live line tool 42 for thepurpose-of disengaging the pin or prong 34 from the eye :or; pull ring. 19; Then-the fuse tube 16 is permitted to; swingv downwardly to the open position. Further manipulation of the live line stick 42'removes the bow In this manner the'circuit isolating device 10 is opened without :thecreation ofvan .unconfinedarc and without requiring-thatthe: fuse linktherein be broken or blown. Subsequently. the fuse tube 16 can be swung tothe closed position torestore the circuit.

When the .bowshaped contact member 29 is removed from ,contact'engagement with the horn or stud 24, it is deenergized: Then. the latch 138 can be moved manually from-registry with the lower end 1420f thetubularinsulating housing 48 and the auxiliarycircuit interrupter .27 carrbe reclosed. by manually returning the inner insulating sleeve 77 to the position. shown in.Figures 2A and 2B of thedrawings.

Since certain further changes can bemade in the foregoing construction and. different embodiments of the invention can be made without departingfrorn the spirit and scope thereof, it is intended that all matters shown in the accompanying, drawings and. described. hereinbefore :shall be interpreted. as. illustrative and not in alimiting sense.

Whatis claimed as new is:

1. A circuit interrupter for opening a high voltage circuit.isolating device such as a disconnecting fuse, disconnectingswitch or the like, normally carrying line current and. havinga normally energized terminal contact member and a current carryingmember movable into .;and out of engagement therewith comprising, in combination, a. tubularinsulating housinghavinga conducting member secured thereto carrying externallyextending contact means for electrical and mechanical connection to said contact member, an inner insulating sleeve relatively slidably mounted withinsaid housing havingaconducting member secured thereto carryingexternally extending contact making means for electricalconnection to said current carrying member; said .contact making means including a conductingarm extending along said tubular insulating housing and movable longitudinallythereof together with'said inner insulating sleeve and havingat. its outer end a longitudinally extending socket with hearings on opposite sides thereof alongian axis perpendicular to the longitudinal axis of said socket, a spring plunger slidably' mounted in said socket having a spring urging the same outwardly, a 'strut' pivot shaft journale d in said bearings and projecting at one end from said conducting arm on the side away from said insulating housing and carrying cam means intermediate its ends for cooperating with saidfispring plunger to bias said strut pivot shaft to a central position, a strut rockably mounted intermediate its ends on said projecting end of said strut pivot shaft transversely of the axis of rotation thereof and biased toward said insulating housing, a prong extending laterally from said strut for electrical and mechanical connection to said current carrying member, and a keeper rockably mounted about two axes at right angles to each other on said strut and cooperating with said prong for engaging said current carrying member, a pair of separable contacts in said sleeve connected respectively to said conducting members, and means for separating said contacts to open the circuit therethrough.

2. A circuit interrupter for opening a high voltage circuit isolating device such as a disconnecting fuse, disconnecting switch or the like, normally carrying line current and having a normally energized terminal contact member and a current carrying member movable into and out of engagement therewith comprising, in combination, a tubular insulating housing having a conducting member secured thereto carrying externally extending contact means for electrical and mechanical connection to said contact member, an inner insulating sleeve relatively slidably mounted within said housing having a conducting member secured thereto carrying externally extending contact making means for electrical connection to said current carrying member; said contact making means including a conducting arm extending along said tubular insulating housing and movable longitudinally thereof together with said inner insulating sleeve and having at its outer end a longitudinally extending socket with hearings in opposite sides thereof along an axis perpendicular to the longitudinal axis of said socket, a headed spring plunger slidably mounted in said socket having a coil compression spring therearound urging the same outwardly, shoulder means in said socket cooperating with the head of said plunger to limit the inward movement thereof, a strut pivot shaft journaled in said bearings and projecting at one end from said conducting arm on the side away from said insulating housing and carrying cam means intermediate its ends for cooperating with said head of said spring plunger to bias said strut pivot shaft to a central position, a strut rockably mounted intermediate its ends on said projecting end of said strut pivot shaft trans versely of the axis of rotation thereof and biased toward said insulating housing, 3. prong extending laterally from said strut for electrical and mechanical connection to said current carrying member, and a keeper rockably mounted about two axes at right angles to each other on said strut and cooperating with said prong for engaging said current carrying member, a pair of separable contacts in said sleeve connected respectively to said conducting members, and means for separating said contacts to open the circuit therethrough.

3. A circuit interrupter for opening a high voltage circuit isolating device such as a disconnecting fuse, disconnecting switch or the like, normally carrying line current and having a normally energized terminal contact member and a current carrying member movable into and out of engagement therewith comprising, in combination, a tubular insulating housing having a conducting member secured thereto carrying externally extending contact means for electrical and mechanical connection to said contact member, an inner insulating sleeve relatively slidably mounted within said housing having a conducting member secured thereto carrying externally extending contact making means for electrical connection to said current carrying member; said contact making means including a conducting arm extending along said tubular insulating housing and movable longitudinally thereof together with said inner insulating sleeve, a strut rockably mounted about two axes at right angles to each other intermediate its ends on the outer end of said conducting arm, a prong extending laterally from said strut for elec trical and mechanical connection to said current carrying member, said strut having a longitudinally extending recess spaced from said prong with bearings on opposite sides along an axis perpendicular to the longitudinal axis of said recess, a keeper plunger slidably mounted in said recess, a spring biasing said keeper plunger outwardly of said recess,

keeper pivot shaft journaled in the last mentioned bearings and projecting at one end from the side of said strut away from said tubular insulating housing and having cam means intermediate its ends cooperating with said keeper plunger to bias said keeper pivot shaft to a central position, and a keeper rockably mounted at one end on said projecting end of said keeper pivot shaft transversely of its axis of rotation and biased away from said strut and cooperating with said prong for engaging said current carrying member; a pair of separable contacts in said sleeve connected respectively to said conducting members, and means for separating said contacts to open the circuit therethrough.

4. A circuit interrupter for opening a high voltage circuit isolating device such as a disconnecting fuse, disconnecting switch or the like, normally carrying line current and having a normally energized terminal contact member and a current carrying member movable into and out of engagement therewith comprising, in combination, a tubular insulating housing having a conducting member secured thereto carrying externally extending contact means for electrical and mechanical connection to said contact member, an inner insulating sleeve relatively slidably mounted within said housing having a conducting member secured thereto carrying externally extending contact making means for electrical connection to said current carrying member; said contact making means including a conducting arm extending along said tubular insulating housing and movable longitudinally thereof together with said inner insulating sleeve, a strut rockably mounted about two axes at right angles to each other intermediate its ends on the outer end of said conducting arm, a prong extending laterally from said strut for electrical and mechanical connection to said current carrying member, said strut having a longitudinally extending recess spaced from said prong with bearings on opposite sides along an axis perpendicular to the longitudinal axis of said recess, a keeper plunger guide at the base of said recess, a headed keeper plunger in said recess having a stem guided in said keeper plunger guide with its movement into said recess being limited thereby, a coil compression spring surrounding said keeper plunger and biasing the same outwardly of said recess, a keeper pivot shaft journaled in the last mentioned bearings and projecting at one end from the side of said strut away from said tubular insulating housing and having cam means intermediate its ends cooperating with the head of said keeper plunger to bias said keeper pivot shaft to a central position, and a keeper rockably mounted at one end on said projecting end or" said keeper pivot shaft transversely of its axis of rotation and biased away from said strut and cooperating with said prong for engaging said current carrying member; a pair of separable contacts in said sleeve connected respectively to said conducting members, and means for separating said contacts to open the circuit therethrough.

5. A circuit interrupter for opening a high voltage circuit isolating device such as a disconnecting fuse, disconnecting switch or the like, normally carrying line current and having a normally energized terminal contact member and a current carrying member movable into and out of engagement therewith comprising, in combination, a tubular insulating housing having a conducting member secured thereto carrying externally extending contact means for electrical and mechanical connection to said contact member, an inner insulating sleeve relatively slidably mounted within said housing having a conducting member secured thereto carrying externally extending contact making means for electrical connection to said current carrying member; said contact making means in- 13 cluding a conducting arm extending along said tubular insulating housing and movable longitudinally thereof together with said inner insulating sleeve and having at its outer end a longitudinally extending socket with bearings on opposite sides thereof along an axis perpendicular tothe longitudinal axis of said socket, a spring plunger slidably mounted on said socket having a spring urging the same-outwardly,a strut pivot shaft journaled in said bearings and projecting at one end from said conducting arm on the side away from said insulating housing and carrying cam means intermediate its ends for cooperating with said spring plunger to bias said strut pivot shaft to a central position, a strut rockably mounted intermediate its ends on said projecting end of said strut pivot shaft transversely of the axis of rotation thereof and biased toward said insulating housing, a prong extending laterally from said strut for electrical and mechanical connection to said current carrying memher, said strut having a longitudinally extending recess spaced from said prong with bearings on opposite sides along an axis perpendicular to the longitudinal axis of said recess, a keeper plunger slidably mounted in said recess, a spring biasing said keeper plunger outwardly of said recess, a keeper pivot shaft journaled in the last mentioned bearings and projecting at one end from the side of said strut away from said tubular insulating housing and having cam means intermediate its ends cooperating with said keeper plunger to bias said keeper pivot shaft to a central position, and a keeper rockably mounted at one end on said projecting end of said keeper pivot shaft transversely of its axis of rotation and biased away from said strut and cooperating with said prong for en gaging said current carrying member; a pair of separable contacts in said sleeve connected respectively to'said conducting members, and means for separating said contacts to open the circuit therethrough.

6. A circuit interrupter for opening a high voltage circuit isolating device such as a disconnecting fuse, disconnecting switch or the like, normally carrying line current and having a normally energized terminal contact member and a current carrying member movable intoand out of engagement therewith comprising, in combination, a tubular insulating housing having a conducting member secured thereto carrying externally extending contact means for electrical and mechanical connection to said contact member, an inner insulating sleeve relatively slidably mounted within said housing having a conducting member secured thereto carrying externally extending contact making means for electrical connection to said current carrying member; said contact making means including a conducting arm extending along said tubular insulating housing and movable longitudinally thereof together with said inner insulating sleeve and having at its outer end a longitudinally extending socket with bearings on opposite sides thereof along an axis perpendicular to the longitudinal axis of said socket; a headed spring plunger slidably mounted in said socket having a coil compression spring therearound urging the same outwardly, shoulder means in said socket cooperating with the head of said plunger to limit the inward movement thereof, a strut pivot shaft journaled in said bearings and projecting at one end from said conducting arm on the-side away from said insulating housing'and carrying cam means intermediate its ends for cooperating with said head of said spring plunger to bias said strut pivot'shaft to a central position, a strut rockably mounted intermediate its ends on said projecting end of said strut pivot shaft transversely of the axis of rotation thereof and biased toward said insulation housing, a prong extending laterally from said strut for electrical and mechanical connection to said current carrying mem ber,said strut having a longitudinally extending recess spaced from said prong with bearings on opposite sides along an axis perpendicular to the longitudinal axis of said recess, a keeper plunger guide at the base of said 14 recess, a headed keeper plunger in said recess having a stem' guided in said keeper plunger guide with its movement into said recess being limited thereby, a coil compression spring surrounding said keeper plunger and biasing the same outwardly of said recess, a keeper pivot shaft journaled in the last mentioned bearings and projecting at one end from theside of said strut away from said tubular insulating housing and having cam means intermediate its ends cooperating with the head of said keeper plunger to bias said keeper pivot shaft to a central position, and a keeper rockably mounted at one end on said projecting end of said keeper pivot shaft transversely of its axis of rotation and biased away from said strut and cooperating with said prong for engaging said' current carrying member; a pair of separable contacts in said sleeve connected respectivelyto said conducting members, and means for separating said contact to open the circuit therethrough.

7. A circuit interrupter for opening a high voltage circuit isolating device such as a disconnecting fuse, disconnecting switch or the like, normally carrying line current and having a normally energized terminal contact member and a current carrying member movable into and out of engagement therewith comprising, in combination, a

tubular insulating housing having a conducting member secured thereto carrying externally extending contact means for electrical and mechanical connection to said contact memeber, an inner insulating sleeve relatively slidably mounted within said housing having a conducting member secured thereto carrying externally extending contact making means for electrical connection to said current carrying member; said contact making means including a conducting arm extending along said tubular insulating housing and movable longitudinally thereof together with said inner insulating sleeve and having a universal joint at its outer end, a strut mounted intermediate its ends on said universal joint, a prong extending laterally from said str ut from electrical and mechanical connection to said current carrying member, and a keeper rockably mounted about two axes at right angles to each other on said strut and cooperating with said prong for engaging said current carrying member; a pair of separable contacts in said sleeve connected respectively to said conducting members, meansfor separating said contacts to open the circuit therethrough, and a latch of insulating material rockably mounted on said conducting arm between said universal joint and said inner insulating sleeve and biased into the path of said insulating housing to hold the same and said inner insulating sleeve in separated position after said contacts have separated.

8. A circuit interrupter for opening a high voltage circuit isolating device such as a disconnecting fuse, disconnecting switch or the like, normally carrying line current and having a normally energized terminal contact member and a current carrying member movable into and out of engagement therewith comprising, in combination, a tubular insulating housing having a conducting member'secured thereto carrying externally extending contact means for electrical and mechanical connection to said contact member, an inner insulating sleeve relatively slidably mounted within said housing having a conducting member secured thereto carrying externally extending contact making means for electrical connection to said current carrying member; said contact making means including a conducting arm extending along said tubular insulating housing and movable longitudinally thereof together with said inner insulating sleeve and having at its outer end a longitudinally extending socket with bearin'gs on opposite sides thereof along an axis perpendicular to the longitudinal axis of said socket, a spring plunger slidably mounted in said socket having a spring urging the same outwardly, a strut pivot shaft journaled in said bearings and projecting at one end from said conducting min on the side away from said insulating housing and carrying cam means intermediate its ends for cooperating with said spring plunger to bias said strut pivot shaft to a central position, a strut rockably mounted intermediate its ends on said projecting end of said strut pivot shaft transversely of the axis of rotation thereof and biased toward said insulating housing, a prong extending laterally from said strut for electrical and mechanical connection to said current carrying member, said strut having a longitudinally extending recess spaced from said prong with bearings on opposite sides along an axis perpendicular to the longitudinal axis of said recess, a keeper plunger slidably mounted in said recess, a spring biasing said keeper plunger outwardly of said recess, a keeper pivot shaft journaled in the last mentioned bearings and projecting at one end from the side of said strut away from said tubular insulating housing and having cam means intermediate its ends cooperating with said keeper plunger to bias said keeper pivot shaft to a central position, a keeper rockably mounted at one end on said projecting end of said keeper pivot shaft transversely of its axis of rotation and biased away from said strut and cooperating with said prong for engaging said current carrying memher, and a contact finger including a conducting sleeve carried by one end of a coil spring the intermediate portion of which is disposed around a shaft carried by said strut and the other end of which bears against said strut for moving said conducting sleeve in alignment with said prong for maintaining contact engagement with said current carrying member; a pair of separable contacts in said sleeve connected respectively to said conducting members, and means for separating said contacts to open the circuit therethrough.

9. A circuit interrupter for opening a high voltage circuit isolating device such as a disconnecting fuse, disconnecting switch or the like, normally carrying line current and having a normally energized terminal contact member and a current carrying member movable into and out of engagement therewith comprising, in combination, a tubular insulating housing having a conductting member secured thereto carrying externally extending contact means for electrical and mechanical connection to said contact member, an inner insulating sleeve relatively slidably mounted within said housing having a conducting member secured thereto carrying externally extending contact making means for electrical connection to said current carrying member; said contact making means including a conducting arm extending along said said tubular insulating housing and movable longitudinally thereof together with said inner insulating sleeve and having at its outer end a longitudinally extending socket with hearings on opposite sides thereof along an axis perpendicular to the longitudinal axis of said socket, a headed spring plunger slidably mounted in said socket having a coil compression spring therearound urging the same outwardly, shoulder means in said socket cooperating with the head of said plunger to limit the inward movement thereof, a strut pivot shaft journaled in said bearings and projecting at one end from said conducting arm on the side away from said insulating housing and carrying a rectangular cam intermediate its ends for cooperating with said head of said spring plunger to bias said strut pivot shaft to a central position, a strut rockably mounted intermediate its ends on said projecting end of said strut pivot shaft transversely of the axis of rotation thereof and biased toward said insulating housing, a prong extending laterally from said strut for electrical and mechanical connection to said current carrying member, said strut having a longitudinally extending recess spaced from said prong with bearings on opposite sides along an axis perpendicular to the longitudinal axis of said recess, a keeper plunger guide at the base of said recess, a headed keeper plunger in said recess having a stem guided in said keeper plunger guide with its movement into said recess being limited thereby, a coil compression spring surrounding said keeper plunger and bias ing the same outwardly of said recess, a keeper pivot shaft journaled in the last mentioned bearings and projecting at one end from the side of said strut away from said tubular insulating housing and having a flat cam surface intermediate its ends cooperating with the head of said keeper plunger to bias said keeper pivot shaft to a central position, a keeper rockably mounted at one end on said projecting end of said keeper pivot shaft transversely of its axis of rotation and biased away from said strut and cooperating with said prong for engaging said current carrying member, and a contact finger including a conducting sleeve carried by one end of a coil spring the intermediate portion of which is disposed around a shaft carried by said strut and the other end of which bears against said strut for moving said conducting sleeve in alignment with said prong for maintaining contact engagement with said current carrying member; a pair of separable contacts in said sleeve connected respectively to said conducting members, means for separating said contacts to open the circuit therethrough, and a latch of insulating material rockably mounted on said conducting arm between said strut pivot shaft and said inner insulating sleeve and biased into the path of said insulating housing to hold the same and said inner insulating sleeve in separated position after said contacts have separated.

10. A circuit interrupter for opening a high voltage circuit comprising, in combination, a tubular insulating housing having a terminal at one end, an inner insulating sleeve relatively slidably mounted within and adapted to project out of the other end of said housing and having a lengthwise extending elongated slot in its outer surface and a sleeve terminal secured to its outer end, a guide key of insulating material secured to said housing intermediate it ends and projecting into said slot for guiding said sleeve, a conductor rod carried at its inner end by said terminal on said housing and extending therefrom into said inner insulating sleeve, a movable first arcing contact in endwise spaced relation to the outer end of said conductor rod, spring and cable means interconnecting said arcing contact and said conductor rc-d, a cam terminal having a latch engaging shoulder carried by said outer end of said rigid conductor, a tubular metallic sleeve secured at its outer end to said first arcing contact and slidably mounted in and extending through said inner sleeve to the inner end thereof, a latch carried by said inner end of said inner sleeve and cooperating with the inner end of said metallic sleeve to effect conjoint movement of said sleeves and extension of said spring and cable means when said inner sleeve is moved outwardly of said housing, said latch being released from said metallic sleeve on engagement with said latch engaging shoulder to permit said first arcing contact and said metallic sleeve to be withdrawn through said inner sleeve under the biasing action of said spring means, and contact means carried by said sleeve terminal for contact engagement with said first arcing contact and constituting a second arcing contact.

11. A circuit interrupter for opening a high voltage circuit comprising, in combination, a tubular insulating housing having a terminal at one end; an inner insulating sleeve relatively slidably mounted within and adapted to project out of the other end of said housing having a metallic inner sleeve end insert telescoped into its inner end, and a sleeve terminal telescoped into its outer end, the interengaging surfaces of the ends of said sleeve and said insert and said sleeve terminal being tapered and cemented together, a conductor rod carried at its inner end by said terminal on said housing and extending therefrom into said inner insulating sleeve, a movable first arcing contact in endwise spaced relation to the outer end of said conductor rod, spring and cable means interconnecting said arcing contact and said conductor rod, a cam terminal having a latch engaging shoulder carried by said outer end of said rigid conductor, a tubular mel7 tallic sleeve secured at its outer end to said first arcing contact and slidably mounted in and extending through said inner sleeve to the inner end thereof, a latch carried by said inner end of said inner sleeve and cooperating with the inner end of said metallic sleeve to effect conjoint movement of said sleeves and extension of said spring and cable means when said inner sleeve is moved outwardly of said housing, said latch being released from said metallic sleeve on engagement with said latch engaging shoulder to permit said first arcing contact and said metallic sleeve to be withdrawn through said inner sleeve under the biasing action of said spring means, and contact means carried by said sleeve terminal for contact engagement with said first arcing contact and constituting a second arcing contact.

12. A circuit interrupter for opening a high voltage circuit comprising, in combination, a tubular insulating housing having a terminal at one end, an inner insulating sleeve relatively slidably mounted within and adapted to project out of the other end of saidhousing and having a sleeve terminal secured to its outer end, a conductor rod carried at its inner end by said terminal on said housing and extending therefrom into said inner insulating sleeve, a movable first arcing contact in endwise spaced relation to the outer end of said conductor rod, spring and cable means interconnecting said arcing contact and said conductor rod, a cam terminal having a latch engaging shoulder and a stop shoulder carried by said outer end of said rigid conductor, a tubular metallic sleeve secured at its outer end to said first arcing contact and slidably mounted in and extending through said inner sleeve to the inner end thereof, a stop ring carried by the inner end of said metallic sleeve for engaging said stop shoulder to limit the extent of withdrawal of said metallic sleeve from said rigid conductor and permit said inner insulating sleeve and sleeve terminal thereon to continue their outward movement, a latch carried by said inner end of said inner sleeve and cooperating with the inner end of said metallic sleeve to effect conjoint movement of said sleeves and extension of said spring and cable means when said inner sleeve is moved outwardly of said housing, said latch being released from said metallic sleeve on engagement with said latch engaging shoulder to permit said first arcing contact and said metallic sleeve to be withdrawn through said inner sleeve under the biasing action of said spring means, and contact means carried by said sleeve terminal for contact engagement with said first arcing contact and constituting a second arcing terminal.

13. A circuit interrupter for opening a high voltage circuit comprising, in combination, a tubular insulating housing having a terminal at one end; an inner insulating sleeve relatively slidably mounted within and adapted to project out of the other end of said housing with a lengthwise extending elongated slot in its outer surface and having a metallic inner sleeve end insert telescoped into its inner end, and a sleeve terminal telescoped into its outer end; a guide key and stop ring of insulating material secured to said housing intermediate its ends with the key projecting into said slot for guiding said sleeve, the interengaging surfaces of the ends of said sleeve and said insert and said sleeve terminal being tapered and cemented together, a conductor rod carried at its inner end by said terminal on said housing and extending therefrom into said inner insulating sleeve, a movable first arcing contact in endwise spaced relation to the outer end of said conductor rod, spring and cable means interconnecting said arcing contact and said conductor rod, a cam terminal having a latch engaging shoulder and a stop shoulder carried by said outer end of said rigid conductor, a tubular metallic sleeve secured at its outer end to said first arcing contact and slidably mounted in and extending through said inner sleeve to the inner end thereof, a stop ring carried by the inner end of said metallic sleeve for engaging said stop shoulder to limit the extent of withdrawal of said metallic sleeve from said rigid conductor and permit said inner insulating sleeve and sleeve terminal thereon to continue their outward movement, a latch carried by said inner end of said inner sleeve and cooperating with the inner end of said metallic sleeve to eifect conjoint movement of said sleeves and extension of said spring and cable means when said inner sleeve is moved outwardly of said housing, said latch being released from said metallic sleeve on engagement with said latch engaging shoulder to permit said first arcing contact and said metallic sleeve to be withdrawn through said liner and inner sleeve under the biasing action of said spring means, and contact means carried by said sleeve terminal for contact engagement with said first arcing contact and constituting a second arcing terminal.

14. A circuit interrupter for opening a high voltage circuit comprising, in combination, a tubular insulating housing, having a terminal at one end, an inner insulating sleeve relatively slidably mounted within and adapted to project out of the other end of said housing and having a sleeve terminal secured to its outer end, a conductor rod' carried at its inner end by and rotatably mounted about its longitudinal axis on said terminal of said housing and extending therefrom into said inner insulating sleeve, a movable first arcing contact in endwise spaced relation to the outer end of said conductor rod, spring and cable means interconnecting said arcing contact and said conductor rod, said first arcing contact and said spring and cable means being rotatable longitudinally of said inner insulating sleeve together with said conductor rod, a cam terminal having a latch engaging shoulder carried by said outer end of said rigid conductor, a tubular metallic sleeve secured at its outer end to said first arcing contact and slidably mounted in and extending through said inner sleeve to the inner end thereof, a latch carried by said inner end of said inner sleeve and cooperating with the inner end of said metallic sleeve to effect conjoint movement of said sleeves and extension of said spring and cable means when said inner sleeve is moved outwardly of said housing, said latch be ing released from said metallic sleeve on engagement with said latch engaging shoulder to permit said first arcing contact and said metallic sleeve to be withdrawn through said inner sleeve under the biasing action of said spring means, and contact means carried by said sleeve terminal for contact engagement with said first arcing contact and constituting a second arcing contact, there being random relative positioning of said arcing contacts resulting from the action of said spring and the rotatable mounting of said conductor rod connected by said spring and cable means to said first arcing contact.

15. A circuit interrupter for opening a high voltage circuit comprising, in combination, a tubular insulating housing having a terminal at one end, an inner insulating sleeve relatively slidably mounted within and adapted to project out of the other end of said housing and having a sleeve terminal secured to its outer end, a conductor rod carried at its inner end by said terminal on said housing and extending therefrom into said inner insulating sleeve, a movable first arcing contact in endwise spaced relation to the outer end of said conductor rod, spring and cable means interconnecting said arcing contact and said conductor rod, a cam terminal having a latch engaging shoulder carried by said outer end of said rigid conductor, a tubular metallic sleeve secured at its outer end to said first arcing contact and slidably mounted in and extending through said inner sleeve to the inner end thereof, a latch carried by said inner end of. said inner sleeve and cooperating with the inner end of said metallic sleeve to effect conjoint movement of said sleeves and extension of said spring and cable means when said inner sleeve is moved outwardly of said housing, said latch being released from said metallic sleeve on engagement with said latch engaging shoulder to permit said first arcing contact and said metallic sleeve to be withdrawn through said inner sleeve under the biasin action of said spring means, and a plurality of contact fingers with longitudinal slots therebetween secured to and disposed around the inner periphery of said sleeve terminal for contact engagement with said first arcing contact and constituting a second arcing contact, said sleeve terminal having vents coextensive and communicating radially with said slots to permit the discharge of arc products therethrough to the atmosphere when said sleeve terminal is moved out of said housing.

16. A circuit interrupter for opening a high volt-age circuit comprising, in combination, a tubular insulating housing having a terminal at one end, an inner insulating sleeve relatively slidably mounted within and adapted to project out of the other end of said housing and having a sleeve terminal secured to its outer end, a conductor rod carried at its inner end by said terminal on said housing and extending therefrom'into said inner insulating sleeve, a movable 'first arcing contact in endwise spaced relation to the outer end of said conductor rod, spring and cable means interconnecting said arcing contact and said conductor rod, a cam terminal having a latch engaging shoulder carried by said outer end of said rigid conductor, a liner of arc extinguishing material within said inner sleeve near its outer end, a tubular metallic sleeve secured at its outer end to said first arcing contact and slidably mounted in and extending through said liner to said inner end of said inner sleeve, a latch carried by said inner end of said inner sleeve and cooperating with the inner end of said metallic sleeve to effect conjoint movement of said sleeves and extension of said spring and cable means when said inner sleeve is moved outwardly of said housing, said latch being released from said metallic sleeve on engagement with said latch engaging shoulder to permit said first arcing contact and said metallic sleeve to be withdrawn through said liner and inner sleeve under the biasing action of said spring means, a plurality of contact fingers carried by said sleeve terminal for contact engagement with said first arcing contact and constituting a second arcing contact, and an arc shield carried by said inner sleeve and coextensive with the outer end of said liner and the inner ends of said contact fingers for protecting the inner surface of said inner sleeve from the heat of the are formed on separation of said arcing contacts.

17. A circuit interrupter for opening a high voltage circuit comprising, in combination, a tubular insulating housing having a terminal at one end, an inner insulating sleeve relatively slidably mounted within and adapted to project out of the other end of said housing and having a sleeve terminal'secured to its outer cnd,,,a conductor rod carried at its inner end by and rotatably mounted about its longitudinal axis on said terminal of said housing and extending therefrom into said inner insulating sleeve, a movable first arcing contact in endwise spaced relation to the outer end of said conductor rod, spring and cable means interconnecting said arcing contact and said conductor rod, said first arcing contact and .said spring and cable means being rotatable longitudinally of said inner insulating sleeve together with said conductor rod, a cam terminal having a latch engaging shoulder carried by said outer end of said rigid conductor, a liner of arc extinguishing material within said inner sleeve near its outer end, a tubular metallic sleeve secured at its outer end to said first arcing contact and slidably mounted in and extending through said liner to said inner end of said inner sleeve. a latch carried by-said inner end .of said inner sleeve and cooperating with the inner end of said metallic sleeve to eifect conjoint movement ofsaid sleeves and eXtfinsion of said spring and cable means when said inner sleeve is moved outwardly of said housing, said latch being released from said metallic sleeve on engagement with said latch engaging shoulder to permit said'first arcing contact and said metallic sleeve to be withdrawn through said liner and inner sleeve under the biasing action of said spring 20 means, a plurality of contact fingers with lie 2"l slots therebetween secured to and disposed around the inner periphery of said sleeve terminal for contact engagement with said first arcing contact and ccnstituti a 0nd arcing contact, there being random relative p dt ing of said arcing contact resulting from the rotatable mounting of said conductor rod connected by said spring and cable means to said first arcing contact, said terminal having vents coextensive and communicati. radially with said slots to permit the discharge of ar arc shield carried by said inner sleeve and coe: with the outer end of said liner and the inner ends of contact fingers for protecting the inner surface of s: inner sleeve from the heat of the are formed on scparation of said arcing contacts.

18. A circuit interrupter for opening a high voltage circuit comprising, in combination, a tubular housing having a terminal at one end; an inner ins sleeve relatively slidably mounted within and adapted to project out of the other end of said housing with a lengthwise extending elongated slot in its outer surface and having a metallic inner sleeve end insert telescoped into its inner end, and a sleeve terminal telescoped into its outer end; a guide key of insulating material secured to said housing intermediate its ends and projecting into said slot for guiding said sleeve, the interengaging surfaces of the ends of said sleeve and said insert and said sleeve termina being tapered and cemented together, a conductor rod carried at its inner end by and rotatably mounted about its longitudinal axis on said terminal on said housing and extending therefrom into said inner insulating sleeve, movable first arcing contact in endwise spaced relation to the outer end of said conductor rod, spring and cable means interconnecting said arcing contact and said con ductor rod, said first arcing contact and said spring and cable means being rotatable longitudinally of said inner insulating sleeve together with said conductor rod, a cam terminal having a latch engaging shoulder a d a stop shoulder carried by said outer end of said ri conductor, a liner of arc extinguishing material within 2: d inner sleeve near its outer end, a tubular metallic sleeve mounted in and extending through said liner to said inner end .of said metallic sleeve for engaging said stop shoulder to limit the extent of withdrawal of said metaliic sleeve from said rigid conductor and thereby the extent of v drawal of said inner sleeve from said housing, carried by said inner end of said inner sleeve and cooperating with the inner end of said metallic sleeve to client conjoint movement of said sleeves and extension of said spring and cable means when said inner sleeve is moved outwardly of said housing, said latch being released from said metallic sleeve on engagement with said latch en ing shoulder to permit said first arcing contact and d metallic sleeve to be withdrawn through said liner and inner sleeve under the biasing action of said spring means, a plurality of contact fingers with longitudinal slot between secured to and disposed around the inner criphery of said sleeve terminal for contact engagement with said first arcing contact and constituting a second arcing contact, there being random relative positioning of said arcing contacts resulting from the rotatable mounting of said conductor rod connected by said spring and cable means to said first arcing contact, said sleeve terminal having vents coextensive and communicating radially with said slots to permit the discharge of are products therethrough to the atmosphere when said sleeve terminal is moved out of said housing, and a metallic arc shield carried by said inner sleeve and coextensive with the outer endof said liner and the inner ends of said contact fingers for protecting the inner surface of said inner sleeve from the .heat of the are formed on separation of said arcing contacts.

19. A circuit interrupter for opening a high voltage circuit isolating device such as a disconnecting fuse, disconnecting switch or the like, normally carrying line current and having a normally energized terminal contact member and a current carrying member movable into and out of engagement therewith comprising, in combination, a tubular insulating housing having a conducting member secured thereto carrying externally extending contact making means for electrical connection to said contact member, an inner insulating sleeve relatively slidably mounted Within said housing having a conducting member secured thereto with an externally extending conducting arm carrying contact making means for electrical connection to said current carrying member, said arm extending along said tubular insulating housing and movable longitudinally thereof together with said inner insulating sleeve and having at its outer end a longitudinally extending socket with bearings on opposite sides thereof along an axis perpendicular to the longitudinal axis of said socket, a spring plunger slidably mounted in said socket having a spring urging the same outwardly, a strut pivot shaft journaled in said bearings and projecting at one end from said conducting arm on the side away from said insulating housing and carrying cam means intermediate its ends for cooperating with said spring plunger to bias said strut pivot shaft to a central position, a strut rockably mounted intermediate its ends on said projecting end of said strut pivot shaft transversely of the axis of rotation thereof and biased toward said insulating housing, a prong extending laterally from said strut for electrical and mechanical connection to said current carrying member, a pair of separable contacts in said sleeve connected respectively to said conducting members, spring means connected to one of said contacts and acting to bias it for movement away from the other contact with a force depending upon the extent of relative movement apart of said housing and sleeve, and means for releasing said one contact for movement under the influence of said spring when said sleeve has been moved relatively away from said housing to a given position.

20. A circuit interrupter for opening a high voltage circuit comprising, in combination, a tubular insulating housing having a terminal at one end, an inner insulating sleeve relatively slidably mounted within and adapted to project out of the other end of said housing and having a sleeve terminal secured to its outer end, a conductor rod carried at its inner end by and rotatably mounted about its longitudinal axis on said terminal of said housing and extending therefrom into said inner insulating sleeve, a movable first arcing contact in endwise spaced relation to the outer end of said conductor rod, spring means interconnecting said arcing contact and said conductor rod, said'first arcing contact and said spring means being rotatable longitudinally of said inner insulating sleeve together with said conductor rod, latch means operatively interconnecting said movable first arcing contact and said inner sleeve to etfect conjoint movement thereof and extension of said spring means when said inner sleeve is moved outwardly of said housing, means for releasing said latch means whereby said first arcing contact is withdrawn through said inner sleeve under the biasing action of said spring means, and contact means carried by said sleeve terminal for contact engagement with said first arcing contact and constituting a second arcing contact, there being random relative positioning of said arcing contacts resulting from the action of said spring means and the rotatable mounting of said conductor rod connected by said spring means to said first arcing contact.

References Cited in the file of this patent UNITED STATES PATENTS

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