US2656435A - High-voltage fuse - Google Patents

Description

Oct. 20, 1953 H. H. FAHNOE 2,656,435

HIGH-VOLTAGE FUSE Filed May 8, 1950 2 Sheet's-Sheet l Insulation 2 Sheets-Sheet 2 Filed May 8, 1950 N m n I m 9 mm om Bm #n En m .Nui

INVENTOR Harold H. Fohoe.

ATTORNEY WITN ESSES:

Patented Oct. 20, 1953 HIGH-VOLTAGE FUSE Harold H. Fahnoe, Wilkinsburg,y Pa., assignor to Westinghouse Electric Corporation, East Pittsburzh, Pa., a corporation of Pennsylvania Application May 8, 1950, Serial No. 160,650

4 Claims. 1 This invention relates generally to circuit interrupters, and more particularly to high voltage fuses. An object of the present invention 1s the provision of a kick-out fusel for effectively and reliably maintaining a fuse holder in circuit closing operation under normal conditions of circuit operation, and for powerfully throwing out the holder upon being subjected to overload eurrent and blowing.

Another object of this invention is the provision of a kick-out fuse having a fuse holder easily manipulated into and out of circuit closing position, and which fuse releasably maintains the holder in the closed circuit position and operates, in response to blowing of the fuse, for releasing and'powerfullyv throwing out the holder.

A further object of this invention is to provide a kick-out fuse which maintains a pivotally mounted fuse holder in circuit closing position during normal circuit operation, and highly effectively imposes bias on the fuse holder for powerfully throwing the same about the pivot as the result of overcurrent conditions in the protected circuit.

A still further object of this invention is the provision of an outdoor fuse in which releasable means for triggering by the blowing operation oi the fuse, is shielded against the effects' of Weather during normal closed circuit operation of the fuse.

Another object of this invention is that of providing a kick-out fuse, having a fuse holder which isv powerfully ejected from the circuit closing position upon circuit conditions blowing the fuse,

and which fuse reliably stops rebound oi" the thrown holder.

Another object of the present invention is to provide a kick-out fuse which is' well suited for keeping a fuse holder in substantially horizontal circuit closing position, yet is highly effective for throwing the holder a safe distance out of the circuit upon the fuse blowing on overload.

A further object of this invention is the provision of a kick-out fuse for supporting a fuse holder in substantially horizontal position for closed circuit operation, and which, upon blowing on overload, is capable of throwing the holder upwardly and away from proximity to the closed circuit position.

These and other objects of this invention will become more apparent upon consideration of the following detailed description of a preferred embodiment thereof, when taken in connection with the attached drawings, in which:

Figure l is a side elevational view of a kick-out 2k fuse constructed in accordance with this invention;

Figure 2 is a plan view ofthe fuse represented in Figure l; and

Figure 3- is an enlarged longitudinal sectional view through the fuse holder of the kick-out fuse shown in Figures 1 and 2.

Referring now more particularly to the structure of fuse I0 represented in Figures l and 2 of the drawings, it will be observed that it is subv stantially identical with the construction described and claimed in I-l'.. L. Rawlins et al. Patent No. 2,403,121, issued July 2, 19,46, to the same assignee of this invention. The fuse of the Rawlins et al. patent is especially adapted for substantially vertical mounting and is arranged to automatically dropy out of the circuit when the fuse blows. As will become apparent as this description proceeds, this invention comprehends the addition of certain structure to the Rawlins et al. fuse having features of cooperationwith that fuse for adapting it to` a substantially horizontal mounting wherein the fuse will be automatically kicked open when the fuse blows. Accordingly, for a detailed description o1 many of the parts of the fuse disclosed herein, reference` may be made to the aforesaid Rawlins et al. patent.

The kick-out fuse disclosed here includes line terminal fixtures H and I2 for connection into a high voltage power line at I4 and i5. These terminals support a fuse holder I6, the latter affording an electrically conductive path complet' ing the line circuit across the terminals during normal operating conditions of the power circuit. The fuse holder, however, includes a fusible portion suited to melt, or blow, when overload conditions in the circuit are encountered; In blowing, the fusible material in the holder prompts operation of releasable means such as the mechanism Il on terminal Il, which opera.- tion releases the holder for being positively thrown to a safe distance away from circuit terminal I4 by biasing action, as of a spring i8 in the vicinity of pivot I9. Considering that the holder I6 is rotatably supported on terminal l2, at pivot I9, it will be seen that utilizing the spring i8, or other biasing means, for applying force to the fuse holder in this vicinity, gives. positive drive of the fuse holder.

The releasable means, such as mechanism l1, preferably is adapted to introduce force aiding the bias and throwing action exerted by spring I8. It will be seen, however, that only short distances of expansion of the spring l-8, or the like, are necessary for applying force in the vicinity of pivot |9 to achieve force application in terms of a relatively large arcuate travel of the free end of the holder 6.

Among uses for certain embodiments of the present invention is that of mounting the fuse in a substantially horizontal direction. Thus. the fuse |9 illustratively is mounted on horizontally spaced insulators 29 and 2|, such as of porcelain, so as to keep the fuse holder I6 in a substantially horizontal position for normal circuit operation. In the horizontal disposition of the fuse, spring I8 alone, or together with any aiding bias, affords force to .throw the holder I6 upward, this occurring upon the fusible means in the latter being blown by an overload current. The throwing action involves rotation of the fuse holder I about the pivot I9.

As further illustrative of the practice of this invention, fuse holder I6 (Fig. 3) includes a fuse tube 3D of insulating material, such as fiber, synthetic resin, or the like, and opposite ends of the fuse tube are adapted to be closed by end terminal caps and 35. The right hand end of tube 39, as viewed in Figure 3, is provided interiorly with a plurality of blocks 3|, of an insulating material which is capable of evolving an arc extinguishing gas when in proximity to an electric arc. The insulating material, of which the blocks are made, is preferably boric acid, but any other insulating material having the properties set forth above may be employed, such, for example, as ber or a synthetic resin.

The insulating blocks 3| are each provided with a central bore 32, so that the alignment of the bores 32, when the blocks are mounted in the tube, forms an elongated arc passage of restricted cross-section. The outer end of the arc passage, formed by the bores 32, is ared outwardly, as shown at 34, and an end block 42 is provided, which acts to separate the blocks 3| from the end cap 35. The end block 42 is preferably of fiber, a synthetic resin or other gas evolving material having a greater mechanical strength than boric acid. An arcing contact rod 31 in normal position is within the arc passage formed by the bores 32, and the outer end 31a of this rod has electrical connection with terminal cap 36 by a fusible strip 38 paralleled by a strain member 39, secured in any suitable manner to the rod and to the terminal cap 35. As shown, fusible strip 38 and strain member 39 have one of their ends inserted in a slot in the end of rod 31 and secured thereto, as by soldering or riveting, and the opposite ends of the fuse strip 38 and strain member 39 are bolted, or otherwise connected, as at 40, to an inwardly bent tongue 4| formed integrally with the terminal cap 36. The fusible strip 33, illustratively, is of silver, zinc, tin, or of an alloy thereof. Strain member 39, paralleling the fusible strip 38, is preferably of an electrically conductive material having greater tensile strength and of higher electrical resistance than the material of the fusible strip 38.

For supporting a conducting washer 59 in the fuse tube 30, at the far end of the insulating blocks 3| from the terminal cap 33, an insulating spacer block 49 is preferably employed. A tube 5| of good electrically conducting material, such, for example, as copper or the like, extends between the conducting washer and a washer 52, also of good conducting material, which is clamped between the terminal cap 35 and the adjacent outer end of fuse tube 38.

The end terminal caps 35 and 36 may be secured in position in any suitable manner, but in the preferred manner, represented in Figure 3, the caps are indented into the cylindrical end surfaces of the fuse tube 39, such as by a pressing operation forming indentations in and around the end cap flanges and engaging the material of the tube. The conducting washer 52 has a central aperture, from the rim of which extend integral locking tongues 53 for a purpose to be hereinafter described. Adjacent to the conducting Washer 58, and on the side thereof nearest the terminal cap 35, arcing contact rod 31 has an enlarged portion 31h having a tapered surface 31e thereon at an end thereof remote from tongues 53 of the conducting washer 52. This tapered surface 31e seats a reduced end coil of a coiled tension spring 54, the opposite end coil of which is held by tongues 53, so that the arcing contact rod is biased outwardly toward end terminal cap 35, and strain member 39 is normally maintained under tension.

To afford a good electrical connection between arcing contact rod 31 and terminal cap 35, tube 5| has integral contact tongues 55 for engagement with enlarged portion 31h of rod 31. Contact tongues 55 are joined with tube 5| by inclined parts 55a adapted to be engaged by one end of a coil compression spring 56, which reacts against Washer 59 to bias contact tongues 55 into engagement with enlarged portion 31h of rod 31. By making the conducting tube 5| long enough to project a slight amount beyond the outer end of insulating tube 38, for example, spring 54 conveniently is availed upon to urge conducting washer 52 into rm contact with tube 5|, and the latter into firm abutment against the conducting Washer 50. This force also, for example, is transmitted by the conducting Washer 50 to the insulating spacers 49, 3|, 33 and 42, onto the cap 36, thereby keeping the several parts closely together.

It will be noted that arcing Contact rod 31 has an integral extension 31d from the enlarged portion 31h, and that the end terminal caps 35 and 36 are each provided with a central aperture, normally closed by displaceable closure disks 51 and 58, respectively, which are releasably maintained in position, such, for example, as by cementing.

Under normal operating conditions of the power line, in which the replaceable fuse element I6 is used, an electrically conductive path through the fuse element I5 may be traced from terminal cap 35 through conducting washer 52, conducting tube 5|, contact portions 55, contact arcing rod 31 and fusible strips 38, 39 to terminal cap 36. When an overload is imposed in the circuit, in which the replaceable fuse element I6 is connected, fusible strip 38 will melt, and strain member 39 will be vaporized shortly thereafter, thus releasing the arcing contact rod 31 and permitting spring 54 to move the latter toward terminal cap 35.

Vi/'hen the fusible strip 33 and strain member 39 are melted, the pressure created in the flared passage 34, augmented by gas evolved from material surrounding the bores 32, will be suiiicient to displace closure disk 53, thereby allowing the gases to escape to the atmosphere. Spring 54 meanwhile moves the contact arcing rod 31 until extension 3M of this rod displaces the closure disk 5i. The extension 31d thus passes through the aperture in terminal cap 35 to the outside of fuse element I6 until, for example, the action of spring 54 is stopped by the abutment of the enlarged portion 31h of the contact arcing rod against tongues 53 on the conducting washer 52.

During circuit interruption, an arc is drawn between the end portion 31a of arcing contact rod 31 and arcing tongue 4I on end cap 36, and since enlarged portion 31h of the contact rod disengages contact portions 55, the current supporting the arc will be carried by spring 54. Inasmuch as the arcing time is very short, it is found that the spring will be undamaged by the passage of current therethrough for such short periods of time. If desired, however, a supplemental electrical connection, such as a ilexible shunt (not shown) may be introduced between the terl.

minal cap and the arcing contact rod 31 to protect the spring 54 during circuit interruption. Likewise, if desired, the extension 31d of the arcing contact rod 31 may be of such size as to introduce a close iit against tongues 53 on the conducting washer 52, and thus be locked by the same against returning into the tube 30, once having projected through the aperture in terminal cap 35.

Referring now more particularly to Figures l and 2 of the drawings, it will be seen that the fuse holder I5 is suited at opposite ends thereof for mounting in the line terminal fixtures I I and I2. Receiving the terminal cap 35 of the fuse holder I6 is a clamp, as for example including a substantially circular holding and mounting ring having a radial protuberance 5I therefrom. Covering this protuberance is a hook-eye and latch fixture 62, more particularly having a substantially channel-shaped base 63 over the protuberanoe and facing the side of terminal cap 35. A screw 64, passing through an aperture in the base 63, threadedly engages internal threads in the protuberance 6I to hold the fixture 62 to the terminal cap 35. Extending outwardly beyond terminal cap 35, xture 62 is provided with integral latch engaging extensions on each side of the terminal cap 35, for a purpose to be described hereinafter. A hook-eye portion v6b is also formed integrally with the latch fixture and depends from the channel-shaped base 63 so as to occupy a forward position inthe fuse assembly I0 and permit manual manipulation thereof about pivot I 9'.

At terminal cap 36, there is likewise provided a clamp, this for example including a substantially circular holding and mounting ring 10 for the fuse holder I6. This ring receives the terminal cap 36 therein, and has a radial protuberance 1I, internally threaded for accommodating a screwv 14, A fixture '52, for supporting and applying force for rotating the replaceable fuse element I6 from normal operating position of this fuse element, illustratively has a substantially channel-shaped base 13 aiording a clamp receiv ing the protuberance 1I and the adjacent side of terminal cap 36. The screw 14 conveniently passes through an aperture in base 13 and threads into the protuberance 1I for holding the several parts assembled to the terminal cap 36. Extending in opposite directions from base 13 of the xture 12 are stub- shafts 15 and 15, each for example having a transverse cross-section presenting opposite flat sides, and opposite arcuate sides interconnecting the flat sides, and affording bearing surfaces for rotation under circumstances which will be more fully described. Toward the back of fuse assembly I6, and behind the fuse holder I6, is a lever portion or projection 11 of the nxture 12. This lever portion extends from the back of base 13 for a distance substantially parallel to the replaceable fuse element I6 and then curves downwardly from the latter, terminating in a curved force receiving portion 18, a substantial distance away from stub shaftsv 15 and 16.

For supporting the fuse holder I6 to insulators 2G and 2l, the insulator 2| preferably is provided with a generally U-shaped pivot contact secured thereto, as, for example, by machine screws 8i extending through a base portion 82 of the contact. Legs 83 of the pivot contact have notches 84' therein, terminating in a keyhole guide edge 85 provided at one side of the notch 84 in each leg and with a retaining edge 85a at the other side. Each leg is also provided with an integral terminal leg portion I5 for connection into ythe power line. Intermediate the legs 83 of the pivot contact, a leaf spring member 86 of a resilient conducting material, together with backing leaf spring members 81 andv 88 are secured to the base 82 of the contact, as by one of the contact mounting screwsy 8 I. With reference to Figure .1, it will be observed that when the fuse holder I6 is mounted with trunnions I5 and 16 received in the keyhole portions 89 of slots S6 in the legs of the contact, thus forming the pivot I9, withdrawal of these trunnions is prevented by engagement of guide arms 9| beneath retaining edges 85a of notches 84. These guide arms SI are lateral extensions of lever portion 11 of the fix-l ture 12. With the parts in the position just mentioned, it will be observed that the left-hand end 86a of the conducting spring 86 presses against the contact fixture 12. Upon pivotal movement of the fuse holder I6 in a clockwise direction (in Figure l) on trunnions 15 and 16 in the pivot I9, the guide arms 9| will first be moved clear of the guide edges 85a. on the pivot contact arms 83, and at this time trunnions 15 and 16 will have their widest dimension presented to the opening S0 in keyhole slot 89, so that for removing the fuse holder from the pivot contact, further rotation thereof in a clockwise direction becomes necessary, as to a position approximately open from the position represented in Figure l. In the open position, just mentioned, the fuse holder IS may be removed from the pivot I9 by properly directed manual force.

Disposed between the back of pivot contact 80 and the insulator 2I, and conveniently having apertures for admitting passage of the screws 8l for securement thereof, is a supporting bracket 19 for the helical spring or iirst biasing means I8. The outer end of this bracket has an offset portion 92 substantially confronting the adjacent curved outer end 18 of the force receiving lever of the xture 12. The helical spring I8, illustratively, has spaced core plugs 93 and 94 inside the opposite ends thereof, and suitably held in place, as by welding to the adjacent last coil of the corresponding end of the spring. Core plug 94' has a threaded shank 95, or the like, extending axially therefrom and through an aperture in the end portion 92 of supporting bracket 19. A washer 91 and nut 36 conveniently serve to hold the spring and cores to the supporting bracket.

The line-terminal contact fixture II preferably includes a generally rectangularly-shaped contact supporting and inclosing hood, having a back wall |86, a partial front wall II, opposite side walls, |02 flared outwardly adjacent the freev corners thereof, as at |63, and a side wall IM joining the other walls just named. Back wall $00 is substantially circular in form, as shown in Figure 2, and has diametrically opposed notches A|05 formed in portions thereof beyond side walls |02 for receiving mounting screws |06, the latter securing the rear wall of the contact nxt-ure II to supporting insulator 20. Terminal portion I4, for connecting a line conductor to the fuse, conveniently assumes the form of a lug integral `with the hood side -wall |04. Interiorly of the contact housing is provided a supporting pin I I0 extending transversely of, and mounted in, the side walls |02, and supporting a floating contact and latch member III for movement within the housing. The floating contact and latch member I I I, illustratively, is in the form of a casting, and, as shown, is substantially rectangular in form including opposite side members II2 secured together by an integral front connecting member |I3 and rear connecting members II4 and ||5. The side legs I I2 of the floating contact are provided with integral extensions IIb` having slots therein for receiving supporting pin I I0. A coil compression spring 'or second biasing means I I'I engages between a supporting lug I I0 on the side wall |04 of the housing and a similar supporting lug |09, formed integrally with the transverse connecting member I I4 of the floating oontact III, to bias this contact in a counterclockwise direction around pin I I0, as viewed in Figure 1. Foating contact III is electrically connected with side wall I 04 of the housing, as by a flexible shunt IIB, secured to this side wall and to crossmember II3 of the contact, for example by inachine screws |20.

Along the edges of side legs I I2 of the iloating contact and latch member III are notches |I2a adapted to receive latch engaging projections 65 of the xture B2. A releasable supporting lever I2| is pivotally mounted between side legs |52 of the floating contact II I by means of a pivot pin |22, and this lever |2I is biased for movement in a clockwise direction about pivot pin |22 into engagement with cross-member II of the contact III by a small compression spring |23, engaging between lever I2| and cross-member II4 of the contact. A supporting lug I2|a is formed integrally with lever I2I for cooperation with an integral supporting lug |24 formed on the rear wall of the contact housing II. A stop lug |25 is also formed integrally with the rear wall |00 of the Contact housing II, for engagement with cross-member II4 of the iloating contact III to limit movement thereof toward the housing wall |04.

It will be observed that, for example, by making the hood or housing II with a partial front wall and that by extending the resulting opening to opposite the side wall |04, free entrance and exit of the adjacent end of the fuse holder I6, is possible during rotation of the fuse holder about pivot I9. The fuse I0, however, preferably includes means for shielding this opening in the housing, and consequently the means inside the housing for releasing the fuse holder I6, against the eiects of weather. This shield, such as the shield |40, preferably covers the front opening in the housing II and part of the adjacent side opening and is displaceable as an incident to the outward movement of the fuse holder I6. Shield I is conveniently made of relatively thin fiat sheet metal, or the like, having a degree of ilexibility and resiliency, such as a Phosphor bronze alloy and is substantially Z-shaped, including an end leg I4I secured to the outside surface of fixture 62, to ring and accordingly to the fuse holder I6, by the screw 64. An intermediate body portion |42 of the shield |40 extends outwardly at an angle (see Figure l) covering the housing opening and terminates in an end |43 which overlaps the partial opening in front wall IDI of the housing II. Leg I4| preferably has an extension |44 abutting and overlapping the fixture 62 to prevent substantial rotation of the shield |40 about screw 62 and thus to keep the shield in the covering position relative to the housing opening.

The operation of the floating contact III and releasable supporting lever 2| described above, upon being initiated from the normal circuit closing position of the fuse assembly I0, as represented in Figure 1, illustratively begins with a triggering action prompted by blowing of the fusible strips 38, 39 in the holder I6 on overload. Vaporization of the fusible strips 38, 39 releases the arcing contact rod 31 for operation by the spring 54, which serves to project the rod, and more particularly extension 31d thereof, through end terminal cap 35, rupturing or displacing the disk 51. In moving outwardly through the end terminal cap 35, the outer end of extension 31d of the holder I6 passes between latch engaging portions 65 of the ilxture 62 and strikes the adjacent end of lever I2 I, this serving to rotate the latter counterclockwise (in Figure l) about the pin |22 and against the bias of spring |23. This rotation of lever |2| moves lug I2 Ia off and clear o1" abutment against the xed lug |24, thus freeing the floating contact member III for counterclockwise rotation about pin I I0 under the driving force of spring I Il. The force of the latter is applied by arms II2 at the notches I |2a to latch engaging portions 65 of the fixture 62. Also, it will be observed that the driving force of spring II'I aids spring I8, the latter applying force to lever extension 'I'I of the fixture 12. Both springs I8 and I'I accordingly are active for initially rotating the fuse holder I6, this rotation, of course, being centered at pivot I9, formed by pivot contact arms 83 and trunnions 'I5 and l5, and the action being that of powerfully throwing the fuse holder I6, and shield |40 attached thereto, upwardly in Figure 1 to produce rotation of at least away from the position 'indicated to a vertical position; and its momentum, aided by the force of gravity, will then cause continued rotation of the fuse holder I6.

It will be observed that normally the latch mechanism and contact parts in terminal II are protected from the Weather by shield |40 which extends over the top opening in terminal I I, and is inclined downwardly and outwardly, over at least the top part of the side opening between walls |02. In the event ice or other foreign substances should build up at the outer end |43 of the shield and/or in the space between it and front wall IOI, the flexible nature of the shield will permit it to bend when the fuse is released to exert leverage on such substance to facilitate breaking away of the shield. The resilience of the shield causes breaking stresses to be applied to the ice at a plurality of points, so that the ice is shattered and falls away. Of course, after such an operation the resilient nature of the shield returns it to its normal position relative to the fuse, and illustrated on the drawings. It will be apparent that somewhat the same result would be obtained if the shield |40 were of rigid construction but pivotally mounted on the fuse and spring-biased to the normal position illustrated.

The fuse assembly I0 preferably includes means for stopping opening movement and'preventing rebound of the thrown fuse I6, such, for example, as a resilient substantially U-shaped clip |36, .having a base I3I bolted, or otherwise secured, as at |32, to the outer end of spring 86 and the backing strip Bl. Legs |33 of the clip |30 extend outwardly on respective sides of the path of rotation of the fuse holder I6, beingA rounded to receive and retain fuse holder i6 and having their outer ends flared outwardly so as to be spread apart upon being struck by the fuse holder and to resiliently grip and frictionally retain the fuse holder to prevent rebound thereof. Since clip |30 is mounted on springs B6 and 81 these act to absorb the shock entailed in the stopping of the opening movement of fuse holder I6.

Holder I6, together with fixture 62, shield |40 and fixture 12 attached to the end caps 35 and 56 thereof, may be inserted in the fuse assembly II) ln the open position of the fuse I0, such as at approximately the position, hereinbefore referred to as being about 180 removed from the position represented in Figure 1, by manipulating the trunnions 'I5 and 'I6 within the openings in the keyhole slot 89 withy the aid of hook-eye 66. This insertion conveniently is achieved with the holder I6 out of engagement with the U-shaped clip |36. Following such insertion, the fuse holder I6 and the attached fixtures are rotated in a counterclockwise direction, as viewed in Figure 1, about the pivot I9. This rotation eventually confronts the flat sides of trunnions 'I5 and I6 to the openings 90 in the keyhole slots 89 and subsequently brings guide arms 9| beneath the guide edges 85a of notches 84, all to prevent escape of the trunnions from the keyhole slot. The counterclockwise rotation, referred to, eventually brings the curved end portion 18 of the force receiving lever arm I'I to abutment against the adjacent face of core plug 93 in the spring I8, this abutment for example being initially achieved with the fuse holder I6 still displaced about 60 from the position represented in Figure 1. Continued movement of the fuse holder I6 in the direction indicated compresses the spring I8, and finally brings the latch portions 65 of the contact xture 62 to bear against the mechanism |'I. If latch lug |2|a has been released from lug |24, the iioating contact III is moved, by closing movement of the fuse, in a generally clockwise direction about its supporting pin IIO, and lug I2Ia of lever I2I engages fixed lug |24 on the contact housing I I and passes over this fixed lug by compression of biasing spring |23. Spring II'I is also compressed, and the mechanism thus resumes the Figure 1 position. It will be seen that the contact mechanism I1 is susceptible to release by manual force applied to the hook-eye 66, as by means of a fuse hook stick. A substantial pull exerted on the hook-eye 66, tending to rotate the fuse holder clockwise in Figure 1 about the pivot I9, causes the latch portions 65 to exert a camming action on the floating contact and latching member I I rotating the latter counterclockwise on lug |24 while compressing spring II1. The fuse holder I6, accordingly, is freed for clockwise rotation by further manual manipulation. Also, when the latch lug I2 Ia is in engagement with lug |24 force may be applied to the hook-eye 66, driving the fuse in a counterclockwise direction, as viewed in Figure 1, from an open position to bring the latch portions 65 to bear against the floating contact member III, driving the latter 10 counterclockwise about lug |24 for engaging portions -65 in notches I I2a.

Thus it will be seen that in this invention there is provided a high voltage kick-out fuse in which the various objects, hereinbefore noted, together with many thoroughly practical kadvantages are successfully achieved. It will be seen that the kick-out fuse is especially adapted for substantially horizontal mounting of the fuse, and readily operates for maintaining the circuit closed during the existence of non-overload conditions, and automatically operates, after blowing upon overload in the closed circuit position, to assume a safe position, assuring thereby an open circuit condition.

Having described a preferred embodiment of this invention in .accordance with the Patent Statutes, it should be understood that the invention is not to be limited to the particular em-r bodiment disclosed herein, inasmuch as it will be obvious, particularly to persons skilled in the art, that many changes and modifications may be made in this particular structure, without departing from the broad spirit and scope of the invention. Accordingly, this invention should be interpreted as broadly as possible and limited only as required by the prior art.

I claim as my invention:

l. ln a kick-out fuse, an elongated fuse holder having fusible means therein connected between spaced terminals on said holder, a line terminal, said line terminal including a housing having top and side openings for accommodating swinging movement of one terminal of said holder, means mounting said holder in a substantially horizontal position with said one terminal thereof in engagement with said line terminal for pivotal movement of said one terminal thereof through an opening in said housing and upwardly away from said line terminal, means biasing said holder in favor of said movement of the holder, a shield mounted on said holder at a position to cover at least the top opening in said housing in spaced relation therefrom when said one holder terminal is in engagement with said line terminal, and movable means inside said housing for normally restraining said one holder terminal against the effect of said biasing means and being releasable in response to fusion of said fusible means.

2. In a kick-out fuse, an elongated 'fuse holder having fusible means therein connected between spaced terminals on said holder, a line terminal, said line terminal including a housing having top and side openings for accommodating swinging movement of one terminal of said holder, means mounting said holder in a substantially horizontal position with said one terminal thereof in engagement with said line terminal for pivotal movement of said one terminal thereof through the opening in said housing and upwardly away from said line terminal, means biasing said holder in favor of said movement of the holder, a shield mounted on said holder at a position to cover at least the top opening in said housing in spaced relation therefrom when said one holder terminal is in engagement with said line terminal, at least the outer end of said shield being resiliently movable relative to said holder, and movable means inside the housing for normally restraining said one holder terminal, against the effect of said biasing means and being releasable in response to fusion of said fusible means.

3. In an outdoor kick-out fuse, an elongated 1 1.. fuse holder having fusible means therein connected between spaced terminals on said holder, a line terminal, said line terminal including a housing having top and side openings for accommodating swinging movement of one terminal of said holder, means mounting said holder in a substantially horizontal position with said one terminal thereof in engagement with said line terminal for pivotal movement of said one terminal thereof through the opening in said housing and upwardly away from said line terminal, and a shield mounted on said holder and movable therewith at a position to cover at least the top opening in said housing in spaced relation therefrom when said one holder terminal is in engagement with said line terminal.

4. In an outdoor kick-out fuse, an elongated fuse holder having fusible means therein connected between spaced terminals on said holder, a line terminal, said line terminal including a housing having top and side openings for accommodating swinging movement of one terminal of said holder, means mounting said holder in a substantially horizontal position with said one terminal thereof in engagement with said line terminal for pivotal movement of said one terminal thereof through the opening in said housing and upwardly away from said line terminal, a shield mounted on said holder and movable therewith at a position to cover at least the top opening in said housing in spaced relation therefrom when said one holder terminal is in engagement with said line terminal, and at least the outer end of said shield being resiliently movable relative to the holder.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,940,203 Bowie Dec. 19, 1933 1,965,391 Pittman et al. July 3, 1934 2,074,913 Johnson Mar. 23, 1937 2,166,782 Lemmon July 18, 1939 2,178,650 Schultz Nov. 7, 1939 2,230,955 Johnson Feb. 4, 1941 2,318,817 Triplett May 11, 1943 2,324,888 Strobel July 20, 1943 2,403,121 Rawlins, et al. July 2, 1946 2,435,844 Rawlins Feb. 10, 1948 2,485,221 Turnham et al. Oct. 18, 1949

Images