US2399495A - Circuit interrupter - Google Patents

Description

April 1946 v. MARES CIRCUIT INTERRUPTER Filed March 6, 1944 2 Sheets-Sheet l my i M? w His Attorney.

April 30, 1946. I v, L MARES 2,399,495

CIRCUIT INTERRUPTER Filed March 6, 1944 2 Sheets-Sheet 2 viigrsnisis. 40 7 Attorney.

Patented Apr. 30, 1946 CIRCUIT INTERRUPTER Virgil L. Mares, Upper Darby, Pa, asslgnor to General Electric Company, a corporation of New York Application March 6, 1944, Serial No. 525,175

11 Claims.

My invention relates to circuit interrupters of the type comprising a fuse for completing the circuit between spaced terminals with means for causing the fuse to be moved from between the terminals after operation, to prevent arcing. Specifically, my invention is an improvement on the invention disclosed and claimed in Williams Patent 2,237,801, granted April 8, 1941, and assigned to the same assignee as the present application.

Fuses for high voltage applications such as in the neighborhood of 100 kilovolts or more become very long and may be in the neighborhood of five feet or more in length. It is usually desirable for such fuses upon operation thereof to drop away from their current carrying position to introduce an isolating gap in the circuit. Owing to the great length of such high voltage fuses it has heretofore been very difficult to provide means for supporting the fuse which would not be damaged when the fuse moved to its dropped out position.

It is an object of my invention to provide a new and improved construction of circuit interrupter employing a high voltage fuse which may drop out of its current carrying position upon operation thereof without damage to its support, and which is simple and compact in structure and generally foolproof in operation.

It is another object of my invention to provide a new and improved terminal assembly for a high voltage switching means.

Further objects and advantages of my invention will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed outwith particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to the accompanying drawings in which Fig. 1 is a side elevational view of the circuit interrupter of my invention in the closed circuit position with certain parts thereof broken away; Fig. 2 is a front elevational view of the lower portion of the circuit interrupter of Fig. l with parts thereof broken away; Fig. 3 is a sectional view taken on line 3-3 of Fig. 2; Fig. 4 is a side elevational view of the lower portion of the circuit interrupter with the circuit interrupter in the drop-out position; Fig. 5 isa sectional view of the lower portion of the circuit interrupter taken on line 5-5 of Fig. 4; Fig. 6 is an exploded view of certain portions of the circuit interrupter of my invention; and Fig. 7 is a side elevational terminal l2 by a flexible conductor 20.

viewsimilar to Fig. 1 illustrating one step in reclosing the circuit by replacing the fuse.

Referring now to the drawings, the interrupting device comprises spaced insulators l0 and H on which are carried upper and lower terminal assemblies including terminals l2 and I3, respectively. Included in the upper terminal assembly is a contact II which is pivoted on a pin l5 carried by cars l6 projecting from thefront of the terminal l2. The contact I4 is biased in a clockwise direction, as viewed in Fig. 1, by a compression spring I! arranged between the front face of the terminal I2 and a boss Ill on the rear of the contact l4. Pivotal movement of the contact I4 is limited by an adjustable stop l9 which is threaded into the lower end of the contact I4 and engages the terminal l2 below the pivot pin I5. The contact I is electrically connected to the Furthermore, upper contact I! is provided with forked contact arms 2|. The construction of the upper terminal assembly described thus far is not my invention but is disclosed in the above mentioned Williams patent.

. engagement by spring means 25.

The circuit between the contacts 14 and 24 is completed by a high voltage expulsion fuse unit which may be of the type shown in Williams Patent 2,043,024, granted June 2, 1936, and assigned to the same assignee as the present application. This fuse unit comprises, as best shown in Figs. 1 and 2, a tubular housing 26 of insulating material having metal ferrules or contacts 21 secured at each end, between which a fusible element, not shown, is electrically connected. The lower end of the fusible element is connected to a flexible conductor 28 which terminates in a conical member 29. A spring 30 surrounding the lower end of the flexible conductor urges a split cup-shaped contact 3| against the conical member 29. Each half of the contact 3| is provided with a tapered wall of the same contour as the conical member 29. The spring 30 which forces the contact 3| downwardly therefore wedges the contact against the inside of the metal ferrule 21 and makes a good contact between the contact 3| and the metal ferrule 21. This lower contact construction is fully disclosed in the above mentloned Williams Patent 2,237,801. If desired, the

- contact construction of Powell Patent 2,335,083,

owing to excessive current flowing therethrough,

the disk 32, the contact 3| and the compression spring 30 are forced through the lower end of the ferrule 27. The force with which these parts are expelled may be increased by the gas pressure resulting from the are which ruptures the fusible element.

A collar 33 having an operating eye 34 is clamped to the upper metal ferrule 21 on the fuse cartridge- The upper edge of the collar 33 is tapered and is adapted to fit into a complementary concave tapered surface on the under side of each contact arm 2| to complete the connection between the contact arms 2| and consequently the upper terminal l2 and the upper ferrule 2'? of the fuse unit. The compression spring forces the contact arm 2| against the upper edge of the collar 33. Since the complementary surfaces of the contact arms are concave the fuse unit is latched in place when the collar 33 is in the position indicated in Fig. 1. The upper end of the fuse unit extends above the contact arms and the contact arms therefore guide its movement,

Before mounting the fuse unit in the switch, a fuse fitting 35, best shown in Figs. 6 and '7, which includes a metal sleeve 36 is placed over the lower ferrule 27. The upper end of this sleeve is split and is provided with adjacent flanges 31 which are clamped together as indicated at 38 to secure the sleeve to the ferrule. Preferably one of these flanges 31 terminates in an eye 39, the purpose of which will be described hereinafter. The fuse fitting 35, as is best shown in Fig. 6, comprises two diametrically opposed, downwardly extending arms 40. The inside of each of these arms is provided with a shoulder 4| which supports the edge of the lower ferrule 21 of the fuse unit but which does not interfere with the downward movement of indicator disk 32 or contact 3|. The fuse fitting 35 is placed on the lower ferrule 21 so that the lower edge of the ferrule engagesthe shoulders 4|, as best shown in Figs. 2 and 5, whereupon the flanges 31 are clamped together to unite the fuse unit,

and fuse fitting to make a rigid electrical and mechanical assembly.

The lower ends of downwardly extending arms 40 are each slotted as indicated at 42. Within slots 42 are pivotally mounted by pins 43 the cams 44, the purpose of which will become apparent as the following description proceeds. The slots 42 are enlarged as indicated at 45 in Figs. 2, 5 and 6, so as to form a circular recess the purpose of which will also become apparent as the following description proceeds.

A trunnion supportin sleeve 46, best shown in Fig. 6, is adapted to be slidably mounted on downwardly extending arms 40 of fuse holder 35, The upward movement of trunnion supporting sleeve 46 on arms 40, or rather the downward movement of fuse holder 35 in sleeve 46,

is limited by shoulders 41 on fuse fitting 35. The trunnion supporting sleeve 46 includes a pair-of diametrically opposed trunnions 48 of circular cross section including an axially extending opening 49 in each trunnion. The outer portion of this opening 49 is threaded to accommodate a spring retaining screw 50, best shown in Fig. 5. Slidably mounted within the openings 49 are plungers 5| biased in an inward direction toward downwardly extending arms 40 by compression springs 52. It will be obvious that when trunnion supporting sleeve 46 is slidably mounted on arms 40 with the openings 49 opposite the openings 45 in arms 46, then the spring biased plungers 5| will move into openings 45, as shown in Fig. 2. causing the cams 44 to rotate to the position indicated in Fig. 2. It will be obvious, furthermore, that with the plungers 5| in this position trunnion supporting sleeve 46 is locked to fuse holder 35. It will be noted that in this locked position the cams 44 extend inwardly so as to be engaged by any parts driven out of the bottom of the fuse tube 26.

The trunnion supporting sleeve 46 also includes downwardly extending portions or extensions 53 from which extend pins 54, the purpose of which will become apparent from the following description. Each of the pins 54 is parallel to and extends in the same direction as the associated trunnion 48. When the trunnion supporting sleeve 46 is latched to the fuse fitting 35, which in turn is clamped to the lower fuse ferrule 21 in the manner indicated in Fig. '7, the fuse is latched to the trunnions and consequently is adapted to be inserted in trunnion supporting means which are associated with the lower terminal assembly 23, to be described hereinafter.

The lower terminal assembly 23 includes a support 55 to which lower terminal I3 is bolted, as indicated at 56. Terminal I3 is connected with contact 24 by means of flexible conductor 56'. The lower portion of support 55 is provided with trunnion receiving notches 5'! arranged at either side of support 55 to receive the trunnions 48. Circumferentially arranged about trunnion receiving notches 51 are inwardly extending bosses 58 which are adapted to engage the pins 54 of trunnion supporting sleeve 46, the purpose of which will become apparent from the following description.

Mounted within support 55 on a pin 59 are a pair of cranks 60 interconnected by a pin 6| at the lower end thereof and each provided with a cam portion 60' at the upper end thereof. Cranks 60 are normally biased in a counterclockwise direction as viewed in Fig. 1 by virtue of a torsion spring 62, one end of which bears against pin 6|, while the other end bears against the portion of support 55 fastened to insulator Pivotally mounted as indicated by pin 63 to the upper end of support 55 is a U-shaped crank 64 including an extension 64' extending from the center of the base of the U. A torsion spring 65 is supported by pin 63 and has one end thereof engaging support 55 while the other end thereof engages the base of the U of U-shaped crank 64, thereby constantly biasing crank 64 in a clockwise direction as viewed in Fig. l. The extension 64 from crank 64 is pivotall connected as indicated at 66 with links 61, which in turn are connected by pin 68 to a cup-shaped receptacle 69 having an open front as indicated at 69' in Fig. 3. The opening 69 is sufficiently large to permit the tubular housing 26 of the fuse to pass freely therethrough. The cup-shaped receptacle 69 is also further supported by links '10 pivotally mounted at H to the cup-shaped receptacle 69. The other ends of links 10 are pivotally supported as indicated at 12 to the front of support 55, It will beobvious then that the spring 65 normally tends to force the links 61 and the cup-shaped receptacle 69 outwardly to the position shown in Figs. 4 and '7. Adjustable screws 13 are provided in the extensions 64" of crank 64, to limit the outward travel of the links 61 and cup-shaped receptacle 69 by engaging the portion of support 55 adjacent insulator H, as is clearly shown in Fig. 4.

When the fuse unit 26 is in the closed current carrying position it would be Very undesirable for the spring 65 to exert a force on receptacle 69, since otherwise the fuse tube which is very long might be stressed to such an extent as to cause breakage thereof. Accordingly I arrange the ends 64" of crank 64 to engage the cam surface 69' of cranks 69 so as to form a latching toggle, as is clearly shown in Fig. 1. With this arrangement, all the force exerted by spring 615 is restrained by the latching toggle and consequently no force is exerted tending to push cup-shaped receptacle 6'9 outwardly.

The eye 39 which is an integral part of fuse fitting 35 is disposed above pin 6| of cranks 6Il so that downward movement of eye 39 which occurs upon Operation of the fuse to be described hereinafter, will strike pin 6| thereby rotating crank 60 in a clockwise direction as viewed in Fig. 1 so as to free crank 64 and permit spring 65 to move crank 64 and consequently cupshap d receptacle 69 to the position indicated in Fig. 4 which movement is limited by adjustable screw 13, Spring 62 will force crank 69 to rotate in a counter-clockwise direction to the position indicated in Fig. 4 with cam surfaces 60' engaging the extensions 64" of crank 64.

Mounted on the fuse unit 26 just above receptacle 69 when the fuse is in the current carrying position indicated in Fig. 1, is a collar 14 preferably adapted to be clamped to the fuse by clamping means 15 and spaced above fitting the proper distance as determined by a conducting rod 99. This rod also provides electrical connection between fuse fitting 35 and collar 14 to prevent corona. This collar is arranged so that when the cartridge fuse moves downwardly upon rupture of the fusible element therein to the position indicated in Fig. 4 collar I4 will move into cup-shaped receptacle 69. Although the fuse tube 26 can freely move through the opening 69' in cup-shaped receptacle 69 the collar 14 will not be able to move through this opening and consequently the outward pivotal movement of the cartridge fuse will be limited to the maximum movement of cup-shaped receptacle 69 as shown in Figs. 4 and '7.

The above described fuse unit and fittings are a complete assembly which is mounted in the switch without disturbing the adjustment of the fusible element within the tubular housing 26.

The operation of the circuit interrupter of my invention will be fairly obvious in view of the detailed description included above. With the fuse unit in closed circuit position indicated in Figs. 1 and 2 rupture of the fusible element will drive the lower contact 3| and the disk 32 out of the bottom of the fuse tube as will be obvious from the disclosure of Fig. 2. This downward movement of the contact 3| and disk 32 will rotate cams 44 in a clockwise direction as viewed in Fig. 2 to the position shown in Fig. 5 and consequently will force plungers 5! out of openings 45 in arms of fuse fitting 35. Fuse fitting 35 is then free to move'downwardly in trunnionsupporting sleeve 46. Such downward movement is not onl caused by the weight of the fuse unit and the fuse fitting 35 mechanically and electrically connected thereto, but is also caused by the action of spring I! of the upper terminal assembly. The fuse unit and fuse fitting 35 therefore move downwardly until trunnion supporting sleeve 46 engages the shoulders 41 on fuse fitting 35. This downward movement is sufiicient to cause collar 74 to move down into cup-shaped receptacle 69. Such downward movement of fuse fitting 35 will also cause eye 39 to engage pin 6| thus turning crank 60 out of latching engagement with respect to crank 64 and allowing spring 65 to push the receptacle 69 andconsequently the fuse unit to the position shown in Fig. 4 which is the open circuit position provid ing sufficient electrical clearance between upper fuse ferrule 21 and contact I4, thereby affording the necessary isolating gap, When the fuse unit moves downwardly, collar 33 is freed from the coacting latching portions of contact arms 2|. By virtue of the adjustable screw 13 the fuse unit will be held in this position, shown in Fig. 4, until removed for replacement.

To remove the cartridge fuse from the lower terminal assembly 23 an ordinary maintenance tool is inserted in eye 34 and the fuse unit is lifted upwardly until the collar 14 is moved out of receptacle 69, thereby enabling the fuse to be swung outwardly and downwardly pivoting about trunnions 48. Pins 54 engaging with bosses 5B prevent the fuse from swinging sidewise and furthermore prevent removal of the fuse from the trunnion receiving notches until it has been rotated sufficiently somewhat approaching the position indicated in Fig. '7 where the pins 54 clear the bosses 58.

It will be evident that during the removal of the fuse unit as described above and particularly when the fuse is moved upwardly so that collar 14 is moved out of cup-shaped receptacle 69 that spring biased p-lungers 5| move into openings 45 and force cams 44 to the reset position indicated in Fig. 2. The trunnion supporting sleeve 46 is thereby locked to fuse fitting 35 and the mechanism is automatically reset for assembly on the new fuse to be substituted for the one which has operated. Thereafter, the fuse fitting 35 is removed from the fuse which has operated, and is clamped to a new fuse.

To install the new fuse unit to which fuse fitting 35 is securely clamped, an operator will engage eye 39 with a suitable maintenance tool and lift the trunnlons 48 into trunnion receiving notches 51 in a manner somewhat as indicated in Fig. 7. In this position the pins 54 clear the bosses 58. Thereafter the maintenance tool may engage eye 34 and the fuse swung into the closed position as indicated in Fig. 1. The arrangement of trunnion supporting sleeve 46 and support 55 is such as to prevent any lateral sway of the fuse. Also pins 54 cooperating with bosses 58 prevent the fuse unit from being lifted out of trunnion receiving notches 5'! while being swung to the closed position. As the fuse unit is pushed into receptacle 69 it begins to move rearwardly and consequently crank 64 begins to rotate in a counter-clockwise direction as viewed in Fig. 4 against the action of spring 65. The ends 64" of crank 64 slide along the cam faces 50 of cranks 69 causing cranks 69 to rotate in a clockwise direction as viewed in Fig. 4. When the fuse unit reaches the closed position indicated in Fig. 1 the cranks 60 and the crank 64 form a latching toggle,

as is clearly indicated in Fig. 1, thereby preventing spring 65 from exerting any force on the fuse unit comprising tubular casing 26. In this closed position spring biased contacts I4 and 24 engage the fuse ferrules 21 to complete the electrical circuit through the fusible element.

It will be obvious that my invention provides a fuse disconnecting switch of the drop-out type which is adapted for use on very high voltage circuits and which will safely move to its droppedout position without damage to its pivotal support since during this dropping-out operation the fuse is firmly supported at a point intermediate the ends thereof. In addition, no undue force is exerted when the fuse is in the current carrying position which would undesirably stress the fuse tube until after rupture of the fusible element therein when the upper end of the fuse unit is automatically unlatched and free to move.

While I have shown and described particular embodiments of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from my invention and I therefore aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric switching device comprising a pair of spaced terminals, a switching unit including an elongated member interconnecting said terminals, means providing a pivoted support for one end of said member, means for pivotally moving said member from between said terminals, and means for engaging said member intermediate the ends thereof only during the operation of said switching unit to support said member While it is moving from between said terminals.

2. An electric circuit interrupter comprising a pair of spaced terminals, a fuse including a tubular housing interconnecting said terminals, means providing a pivoted support for one end of said fuse, means for pivotally moving said fuse from between said terminals, and means for engaging said housing intermediate the ends thereof upon operation of said fuse to support said fuse during its movement from between said terminals.

3. An electric circuit interrupter comprising a pair of spaced terminals, a fuse including a housing electrically interconnecting said terminals, means providing a pivoted support for one end of said fuse unit, means for pivotally moving said fuse unit from between said terminals, means for engaging said housing intermediate the ends thereof upon operation of said fuse unit to support said fuse unit during its movement from between said terminals, and means for rendering said means for pivotally moving said fuse unit ineffective until after said fuse has operated.

4. An interrupting device comprising a pair of spaced terminals, a fuse housing having a fusible element therein, a hinged fitting for said housing in which said housing is longitudinally slidable, latch means between said housing and support for preventing sliding of said housing in said support, said means being rendered ineffective by operation of said fusible element, means released by longitudinal movement of said housing for holding said housing between said terminals, means exerting a force on said fuse housing for moving said housing from between said terminals,

and means for rendering said last mentioned means ineffective to exert any force on said housing until after rupture of said fusible element.

5. An interrupting device comprising a pair of spaced terminals, a fuse unit including a housing having a fusible element therein, a hinged support for said fuse unit in which said fuse unit is longitudinally slidable, latch means between said fuse unit and support for preventing sliding of said fuse unit in said support, said means being rendered ineffective by rupture of said fusible element, means released by longitudinal movement of said fuse unit for holding said fuse unit between said terminals, a cup-shaped receptacle having an opening in the side thereof through which said fuse unit may move adapted to slip over said fuse unit intermediate the ends thereof, means for movably supporting said receptacle from one of said terminals, a collar on said fuse unit normally above said receptacle but adapted to move into said receptacle upon longitudinal move-v ment of said fuse unit following rupture of said fusible element, said collar being too large to move through the opening in said receptacle so that when said collar is in said receptacle said fuse unit is supported from said one terminal intermediate the ends thereof, means exerting a force on said fuse unit through said receptacle for moving said fuse unit from between said terminals, and means for rendering said last mentioned means ineffective to exert any force on aid housing until after rupture of said fusible element.

6. An interrupting device comprising a pair of spaced terminals, a fuse unit including a housing having a fusible element therein, a hinged support for said fuse unit in which said fuse unit is longitudinally slidable, latch means between said fuse unit and support for preventing sliding of said fuse unit in said support, said means being rendered ineffective by rupture of said fusible element, means released by longitudinal movement of said fuse unit for holding said fuse unit between said terminals, spring means for exerting a force on said housing for moving said fuse unit from between said terminals, and latching means for rendering said last spring means ineffective to exert any force on said housing until after rupture of said fusible element.

7. An interrupting device comprising a pair of spaced terminals, a fuse unit including a housing having a fusible element therein, a, hinged support for. said fuse unit in which said fuse unit is longitudinally slidable, latch means between said fuse unit and support for preventing sliding of said fuse unit in said support, said means being rendered ineffective by operation of said. fusible element, means released by longitudinal movement of said fuse unit for holding said fuse unit between said terminals, spring means for exerting a force on said housing for moving said fuse unit from between said terminals, latching means for rendering said last mentioned means ineffective to exert any force on said housing, and means responsive to the longitudinal movement of said fuse unit following rupture of said fusible element for releasing said latching means.

8. An interrupting device comprising a pair of spaced terminals, a fuse unit having a fusible element therein, a hinged support for said fuse unit in which said fuse unit is longitudinally slidable, latching means between said fuse unit and support for preventing sliding of said fuse unit in said support. said means being rendered ineffective by rupture of said fusible element, means released by longitudinal movement of said fuse unit for holding said fuse unit between said terminals, cup-shaped receptacle having an opening in the side thereof through which said fuse unit may move adapted to slip over said fuse unit intermediate the ends thereof, means for movably supporting said receptacle from one of said terminals, and a collar on said fuse unit normally above said receptacle but adapted to move into said receptacle upon longitudinal movement of said fuse unit following rupture of said fusible element, said collar being too'large to move through the opening in said receptacle so that when said collar is in said receptacle said fuse unit is supported from said one terminal intermediate the ends thereof.

9. An. interrupting device comprising a pair of spaced terminals, a fuse unit including a housing having a. fusible element therein, a hinged support for said fuse unit in which said fuse unit is longitudinally slidable, latching means between said fuse unit and support for preventing sliding of said fuse unit in said support, said means being rendered ineffective by rupture of said fusible element, means released by longitudinal movement of said fuse unit for holding said fuse unit between said terminals, a cup-shaped receptacle having an opening in the side thereof through which said fuse unit may move adapted to slip over said fuse unit intermediate the ends thereof, means for movably supporting said receptacle from one of said terminals, a collar on said fuse unit normally above said receptacle but adapted to move into said receptacle upon longitudinal movement of said fuse unit following rupture of said fusible element, said collar being too large to move through the opening in said receptacle so that when said collar is in said receptacle said fuse unit is supported from said one terminal intermediate the ends thereof, spring means exerting a force on said housing through said receptacle for moving said fuse unit from between said terminals, latching means for rendering said last mentioned means ineffective to exert any force on said housing until after rupture of said fusible element, and means for releasing said latching means upon rupture of said fusible element.

10. An interrupting device comprising a pair of spaced terminals, a fuse housing having a fusible element therein, a hinged fitting for said housing in which said housing is longitudinally slidable, latch means between said housing and support for preventing sliding of said housing in said support, said means being rendered ineffective by operation of said fusible element, means released by longitudinal movement of said housing for holdin said housing between said terminals, means exerting a force on said fuse housing for moving said housing from between said terminals, mean for rendering said last mentioned means ineffective to exert any force on said housing until after rupture of said fusible element, and means for automatically resetting said last mentioned means upon reclosing the circuit through said interrupting device.

11. An interrupting device comprising a pair of spaced terminals, a fuse unit including a housing having a fusible element therein, a hinged support for said fuse unit in which said fuse unit is longitudinally slidable, latching means between said fuse unit and support for preventing sliding of said fuse unit in said sup ort, said means being rendered ineffective by rupture of said fusible element, means released by longitudinal movement of said fuse unit for holding said fuse unit between said terminals, a cupshaped receptacle having an opening in the side thereof through which said fuse unit may move adapted to slip over said fuse unit intermediate the ends thereof, means for movably supporting said receptacle from one of said terminals, a collar on said fuse unit normally above said receptacle but adapted to move into said receptacle upon longitudinal movement of saidfuse unit following rupture of said fusible element, said collar being too large to move through the opening in said receptacle so that when said collar is in said receptacle said fuse unit is supported from said one terminal intermediate the ends thereof, spring means exerting a force on said housing through said receptacle for moving said fuse unit from between said terminals, latching means for rendering said last mentioned means ineffective to exert any force on said housing until after rupture of said fusible element, means for releasing said latching means upon rupture of said fusible element, and means for automatically restressing said spring means and resetting said latching means upon reclosing the circuit through said interrupting device.

VIRGIL L. MARES.

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