US2165156A - Fuse construction - Google Patents

Description

July 4, 1939. w. o. scHULTz 2,165,156

FUSE CONSTRUCTION Filed Aug. l2, 1937 3 Sheets-Sheet l 5 6 jig] /9 /0/3 z/ A ORNEY.

Ill

July 4, 1939 w. o. SCHUL-rz 2,165,156

FUSE CONSTRUCTION Filed Aug. l2, 1937 3 Sheets-Sheet INVENTOR. I //zz//w 0. 5k/Mrz ATTORNEY.

July 4, 1939 w. o. scHuLTZ FUSE CONSTRUCTION Filed Aug. y12, 1937 3- Sheets-Sheet 3 INVENTOR.

' ATJRNEY.

Patented July d, 1939 UNITED STATES PATENT OFFICE FUSE CONSTRUCTION Application August 12,

Z5 Claims.

/This invention relates to a fuse construction and is particularly directed to a fuse construction associated with a transformer or other electrical device. Y

'Ihis invention is intended to provide a fuse construction which is particularly useful on a single bushing transformer which is now quite common for rural service, though it is applicable to other types of transformers and in its l broadest aspect the invention is not limited to a fuse construction mounted upon a transformer.

The single bushing transformers are made up `with only one primary bushing, the other side of the primary winding being solidly grounded ll to the transformer case.

Objects vof this invention are toA provide a fuse construction in which the fuse structure is carried by or supported from a base which may constitute the casing of a transformer, in which the m support vmay be, and usually is, of conducting material, as, for example, the metallic case of a transformer, and in which the arrangement of parts is such that under all conditions the discharge of gases and any metallic vapors from the fuse is directed away from the metal base which, as stated, may be the metallic casing of the transformer.

Further and more specific objects are to pro- A vide a fuse construction in which the fuse unit,

o such, for instance, as a fuse tube, rocks in a substantially horizontal position and swings about a substantially vertical pivot from operative to inoperative position, and in which the fuse tube may be readily removed from its sup- 35 port in a very simple manner, as, for example, by lifting it directly upwardly from the pivot support to thus permit the complete removal of the fuse unit during re,fusing, the repositioning being equally simple andas easily performed.

Further objects are to provide a construction which is particularly suited for protecting a. transformer, in which the fuse may be mounted Von the transformer in a very simple manner, and in which surge protection is afforded even when 45 the fuse blows by the combined construction of fuse and spark gap.

Further objects are to provide aconstruction which is so made that the lineman may readily reclose the fuse by a horizontal motion without the danger of the fuse discharging gases towards the lineman during this operation, the construction affording an easily manipulable fuse device which discharges the gases and metallic vapors u in a substantially horizontal direction so that v1937, Serialv No. 158,653

the maximum safety for the lineman during reclosing of the device is thus afforded.

Further objects are to provide a fuse construction which is suitable for use on a transformer provided with a primary bus g, in which the fuse is so made and the parts so arranged that the fuse unit is supported from the bushing of the transformer, and in which there are no excessive strains placed on this bushing either when the fuse blows or when it is rocked back into operative position.

Embodiments of the invention are shown in the accompanying drawings, in which: A

Figure 1 is a fragmentary side elevation showing one form of the invention.

Figure 2 is a plan view, with parts in section and broken away. y

Figure 3 is a detail view of a modified form of fuse tube.

Figure 4 is a view corresponding to Figure 1 showing a further form of the invention.

Figure 5 is a horizontal view, partly in section with parts broken away, of the construe-.v tion shown in Figure 4.

Figure 6 is a sectional view on the line 6--6 of Figure 5.

Figure 7 is a fragmentary view of the latching portion of Figure 5 showing the tip of the fuse cap in section.

In Figure 1 the metal casing of the transformer is indicated by the reference character i, the insulating primary bushing by the reference. character 2 and a supporting insulator by the reference character 3. A conductor, not shown, passes through the primary bushing 2 in the usual manner and terminates in the terminal member l. This terminal member may be provided with a lower cap portion 5' which directly contacts with the upper end of the insulating bushing 2.

The terminal member 4 is in the form of a housing and is Yprovided with an upstanding pivot pin 5. Immediately above the pivotpin the housing is cut away, as indicated at 8, and it is to be noted from Figure 2 that two sides '45 of the housing are open. v

The fuse unit comprises the insulating fuse tube 1 which is open at both ends. The pivot end of the fuse tube is provided with a ttingA 8 rigidly mounted thereon andv pivotally supported on the pin 5.

The other or free end of the fuse tube is pro- 'vided with an outwardly projecting arm or support 9 to which is pivoted the metal contact lever or movable contact i0 ci the fuse tube. 'I'his 55 with an end button I6 which normally closes one of the open ends of the fuse tube, as shown in Figure 2. Preferably a leaf spring or contact spring |1 is carried within the terminal 4 and bears against the button or head I6 of the fuse link.

The contact lever III also constitutes a. releasing member. It is held in piace by the vfuse link as long as the fuse link is intact. It is provided with a vertical end wall which constitutes a latch I8. This latch may have its face bevelled,

as 'shown in Figure 2, for a purpose that will hereinafter appear.

The lever I0 straddles the supporting arm'9 and is pivoted thereto by the pivot pin I9. It is held in the position shown in Figure 2- when the fuse link is intact. Under normal conditions, that is to say, when the fuse is in operative position, the latch I6 of the lever I0 is positioned behind the outwardly turned latching member 26 of the spring 2|.

In rocking ,the fuse about the pivot pin 5 towards closed position, it is obvious that the spring 2| is deflected. by th-e bevelled face of the latch |8 and also due tothe fact that the major portion of the spring 2|, that is to say, that portion thereof whichv is first engaged by the 'latching lever or contact lever Ill when the tube is swung into closed position, is itself slanting and thus acts in the manner of a cam and is radially deflected to allow `the latch I8 to pass behind the catch portion of the spring. This spring also is provided with a curved bearing arm or contact portion 22 which engages the flat outer face of the member |8 and urges the fuse tube towards rocking motion about the pivot pin 5. The springs 2| and 22, which, as stated, may be integral if desired and as shown in Figure 2, are securely mounted on the ,terminal member 23, such terminal member being supported from the insulator 3 and being in the form of a small hood housing the major part of the levertlil and housing the spring or springs 2| and 22. 'Preferably a terminal receiving contact tongue 24 is secured in direct contact with the contact spring, as shown most clearly in Figure 2.

The terminal member'23 has an outwardly and downwardly turned spark linger 25 which is positioned above the pin or finger 26 carried by the casing I so that the two fingers 25 and 26 constitute a spark gap for surge protection, the live side of the line being connected to the terminal member 23 through the medium of the contact tongue 24, for example.

It is obvious that under normal conditions the fuse is retained in its operative position, as shown in Figures 1 and 2. However, when an overload occurs, the gases are expelled from the operi end of the fuse tube adjacent the contact and latching lever I8. The pressure of the spring 22 urges the fuse tube towards rocking motion about the pivot pin 5 and the contact spring I1 also urges the tube in the same direction. It is "clear that jwhen the fuse link is rupturedfthe lever I0 is released and rocks to releasing position free of the latching spring 2| and thus allows the fuse tube to rock about the pivot pin 5 from operative to inoperative position.

The. device may be readily re-fused as it iS 'arms 33.

clear that the tting 8 will rock into such a position that the fuse tube may be lifted directly upwardly, the tting 8 or pivot support arm rigidly carried by the fuse tube being then at that point of the terminal member or housing 4 which is cut out, as is indicated at 6 in Figure 2.l Obviously, therefore, the fuse may be removed by lifting it directly upwardly. It may be re-fused and may be replaced. lThereafter the lineman, through the medium of suitable instruments, for instance a switch stick, may push the fuse into closed position, the latch I8 freely riding into locking position behind the spring 2|.

It is obvious that the device need not necessarily employ a fuse tube open at both ends, as shown in Figure 2, as obviously the usual terminal 21 may be carried by the fuse tube 28, see Figure 3, and the terminal cap 29 may be screwed onto the terminal to clamp the end button of the fuse link in place in accordance with the usual practice.

Referring to the form of the invention shown in Figures 4 to '7 the same general principle of construction is followed as that hereinbefore described. The transformer casing is indicated at 30, the primary bushing at 3| and the terminal for the primary winding at 32. This terminal preferably includes an upright portion as shown in Figures 4 and 5 to which is bolted a U-shaped spring contact member 33. This contact member is of double or looped, relatively springy construction and the two arms thereof are substantially parallel throughout the major part of their length and are bent into a U-shape, as viewed in Figure 5. Preferably a small retaining clamp 34 is carried by the arms 33 and is provided with overlapping lips to prevent relative shifting of the 'Ihe alms 33 diverge, as indicated at 33' in Figure 7, to provide a guiding section for guiding the. tip 35 of the contact cap 36 of the fuse tube 31. The arms 33 are bent inwardly the fuse tube Iand thus insure good contact when.

the fuse is in operative position.

It is preferable to provide a metal ring or plate 39 at the lower end ofthe bushing 3|, see Fig-- ure 4. This forms a support to which the upwardly and outwardly extending metallic supporting arm 40 is secured by welding or inY any other suitable manner, or. if desired, the arm 40 can be made integral with the mmber 39. 'Ihe metal plate 39 and the arm 40 constitute a metallic support which is grounded on the metallic casing 30. The arm 40 can'ies the sup.- porting insulator 4I which in turn carries the terminal 42, which is adapted to be connected in any suitable manner, as by means of the connector 43, with the live side of the incoming line. The terminal 42 includes a vertical pin 44 and a spark finger 45 extends outwardly from the terminal and projects downwardly towards the'adjustable spark finger 46 carried by the supporting arm 40.

The fuse tube 31 is provided with an outwardnut 5|, as shownmost clearly in Figure 5, the 1 fuse Ilinl including a reduced fusible -section 52, the end button ofJthe fuse link being clamped between the fitting 53 and the terminal cap 35 in the usual manner.

The lever 48 has its two arms joi'ned by a sleeve 54 and also joined by a web 55 spaced from the sleeve 54, as shown in Figure 5. The lever 43 is pivotally and removably mounted upon the vertical pin 44.

A spring 56 is coiled about the sleeve 54 and has one end bearing against the upstanding -portion of the terminal 42 and the other end bearing against a pin 58 carried by the lever 48. A much lighter spring 51 is coiled about the pivot pin 51' and has one end bearing against an Aextension 41 of the arm 41. The relatively heavy spring 5B tends to rock the lever 48 in a counterclockwise direction, and the relatively lighter spring 51 tends to rock the tube 31 in a-,counterclockwise direction about the pivot pin 51', that is to say, the relatively lighter spring 51 tends to maintain the tube 31 and the lever 48 in their relative positions, as shown in Figure 5.

When the fuse blows, the metallic gases and metallic vapors are expelled in a horizontal direction out of contact with either the metal supporting arm or the metal casing 3D of the transformer. Rupturing of the fuselink ,releases the lever 48 and allows the lever to rock in a counterclockwise direction under the iniiuence of the relatively heavy spring 56 and this withdraws the tip 35 from the contact arms 33. The action of the heavy spring is opposed to that of the lighter spring 51. However, as the tube moves towards inoperative position under the iniluence of the spring 56 due to the rotation of the lever 48 about its pivot 44, the tip 35 of the outer contact of the fuse tube clears the contact arms 33 and the spring rocks the tube Ioutwardly clear of the stationary contact.

The lighter spring 51 now comes into play and moves the tube 31 up against the arm of the lever 48 so that the lever 48 and the tube 31 occupy the same relative position as they are shown in Figure 5. The springr 55, however, rotates the tube 31 and lever-48 until the tube is approximately at right angles to the position shown in Figure 5. The tube cannot loosely rock-about the pivot pin 51 as the spring 51 maintains the same relative position of the tube 31 and lever 48.

Obviously in re-fusing it is merely necessary to lift the fuse unit upwardly from the pin 44. Thereafter it may be readily re-fused and replaced after re-fusing upon the pin 44 and rocked back into service, preferably a manipulating eyelet member 59, see Figure 5, being provided.

It will be seen that a novel form of fuse construction has been provided by this invention in which the fuse swings in a horizontal direction and the discharging gases and metallic vapors are projected in a horizontal direction away from the transformer casing or other metallic support upon which the fuse construction may be carried. Also it is a simple matter for a lineman to re-fuse the device after it is detached and to rock it into place by a horizontal swinging motion imparted to the fuse unit by a switch stick or other suitable member so that even if the fuse blows immediately upon reclosing, the discharge of gases is away from the lineman and is not downwardly in a direction towards the lineman. Greater safety is thus secured and extreme ease in the manipulation of the device is obtained.

Further the construction is very simple and employs a relatively small number of simple and relatively inexpensive parts.

It is to be noted that the form of horizontal swinging tube construction shown in Figure 1 could be employed as a. unitary structure, asl shown in Figure 4, or the form of horizontal swinging tube construction shown in Figure 4 could be carried on insulators from the transformer housing or any other support without departing from the spirit of this invention.

Although this invention has been descri-bed in considerable detail, it is to be understood that such description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

I claim:

1. A fuse construction comprising a support, a fuse unit adapted to move laterally ina substantially horizontal plane spaced from said support, a pair of terminals normally electrically connected by said fuse unit, said fuse unit being movably supported from one terminal and having a free end movable away from the other terminal from operative to inoperative position, and latch means normally holding said fuse unit in operative position, said fuse unit including a fuse link normally-restraining said latch means ircm releasing.

2.l A fuse construction comprising a support, a fuse unit adapted to swing laterally in a substantially horizontal plane spaced from said support, a pair of terminals normally electricallyconnected by said fuse unit, said fuse unit being pivotally supported Ifrom one terminal and having a free end adapted to swing away from the other terminal from operative to inoperative position, and latch means normally holding said fuse unit in operative position, said fuse unit including a fuse link normally restraining said latch means from releasing.

3. A horizontal fuse construction comprising spacedterminal members, a fuse unit normally electrically connecting said terminal members, means movably supporting said fuse unit g for horizontal motion away from one of said terminal members from operative to inoperative position, and means biasing said fuse unit for motion towards inoperative position, said fuse unit including a fuse link normally restraining said fuse unit against motion towards inoperative position.

4. A horizontal fuse construction comprising a pair of spaced contacts one of which is provided with a substantially vertical pivot pin, a fuse unit normally electrically connecting said contacts and being pivoted upon said pin adjacent one end and having a free end normally engaging the other of said contacts, means biasing said fuse unit for swinging motion about said pin, and a fuse link normally restraining said fuse unit against swinging motion.

5. A horizontal fuse construction comprising a pair of spaced contacts one of which is provided with a substantially vertical pivot pin, a fuse unit normally electrically connecting said contacts and being pivoted upon said pin adjacent one end and having a free end normally engaging the other of said contacts, means biasing said fuse unit for swinging motion about said pin, latch means having a portion movable with respect to said fuse unit for normally preventing swinging motion of said fuse unit, and a fuse link normally holding said latch means against releasing motion.

6. A fuse construction comprising a pair of stationary contacts, one of said contacts having a substantially vertically arranged pivot member, a fuse unit mounted in a substantially horizontal position and supported from said pivot member` adjacent one end, cooperating releasable latching means having parts carried jointly by the other end of lsaid fuse unit and the other of said statioenary contacts, means urging said fuse unit in a direction to move said last mentioned end away from said last mentioned stationary contact, and

a fuse link forming a portion of said fuse unit and normally restraining said latching means against releasing motion.

7, A fuse construction comprising a pair of stationary contact members, a fuse unit pivotally mounted adjacent one'end of said unit upon one of said stationary contact members, means `biasing said fuse unit towards pivotal motion in a substantially,4 horizontal direction, releasable means temporarily locking the' other end of said fuse unit to the other of said stationary contact members, and a fuse link restraining said releasable means against releasing motion.

8. A.fuse construction comprising a pair of stationary contacts, one of said stationary contacts having a substantially vertical pivot member, a fuse tube provided with a iitting adjacent one end pivotally mounted upon said pivot member and supporting said fuse tube for horizontal swinging motion about'said pivot member, the other of said stationary contacts having catch means, and a latching member carried by the other end of saiod fuse tube and detachably engaging said catch means, said fuse construction including means biasing said fuse tube towards pivotal motion about said pivot member, and a fuse link carried by said fuse tube and normally restraining said latching member against releasing motion.

9. A fuse construction comprising a pair of spaced insulating members, a pair of stationary contacts carried by said insulating members, one of said stationary contacts having a substantially vertical pivot pin and having a housing with a cut away portion adjacent said pin, a fuse tube having an arm rigidly mounted thereon and projecting from adjacent one end and pivotally mounted upon said pivot pin, the other end of said fuse tube being free, said fuse tube being removable from said pivot pin when said arm is swung into a position adjacent the cut away portion of said housing, means biasing said fuse tubeA towards pivotal motion about said pivot pin, and a fuse link normally electrically connecting said stationary contacts and restraining the free end of said fuse tube from motion way from said last mentioned stationary contac 10. A fuse construction comprising a pair of stationary contacts, each of said stationary contacts including a housing, one of said stationary contacts having a substantially vertical pivot member, a fuse tube supported adjacent one end from said pivot member and having such end normally located within the housing of the corresponding stationary contact, the other end of i said fuse tube being free, catch means housed within the housing in the other of said stationary contacts, a releasable latch member projecting from the free end of said fuse tube and normally projecting into the housing of .the last mentioned stationary contact and releasably engaging said latch, said fuse construction including means biasing said fuse tube for pivotal motion about said pivot member, and a fuse link normally restraining said latch against releasing motion.

11. In an apparatus of the class described, an electrical device having a metal casing, an insulating bushing carried by said casing and supporting a stationary contact having a substantially vertically arranged pivot member, a fuse tube mounted in a substantiallyhorizontal posispaced insulating members, a stationary contact carried by one of said insulating members and including catch means, a second stationary contact carried by the other of said insulating members and having a substantially vertically positioned pivot member, a fuse tube having a free end normally engaging said catch means, supporting means carried adjacent the other end of said fuse tube and pivotally supported from said pivot member, said supporting means pivotally supporting said fuse tube from said pivot member for swinging motion about said pivot member and re-,

leasably holding the free end of said fuse tube in engagement with said catch means, means biasing said fuse tube for swinging motion about said pivot member, yand a fuse link controlling the g action of said supporting means.

13. A unitary fuse construction comprising a conducting supporting member adapted to be at'- tached to a suitable support, a pair of insulators projecting upwardly therefrom, said insulators having stationary contacts and one of said contacts having a pivot support, a fuse tube pivotally supported adjacent one end thereof from one of saidstationary contacts and mounted in a horizontal position for swinging motion in a horizontal plane about the pivot support, said fuse tube having a free end, the other of said stationary contacts including catch means normally engaging the free end of said fuse tube, means biasing said fuse tube for horizontal swinging motion about the pivot support, and a fuse link restraining said fuse tube against swinging motion.

14i A fuse construction comprising a pair of spaced stationary contacts, one of said contacts having a substantially vertical pivot member, the other of said contacts having latch means, a fuse tube mounted in a horizontal position, jointed link mechanism adjacent one end of said fuse tube and pivotally supported from said `pivot member for Supportingsaid fuse tube for swinging motion in a horizontal plane about said pivot lnember, said jointed link mechanism normally holding the other end of said fuse tube in latching relation to said latch means, means biasing said fuse tube towards swinging motion, and a fuse link normally holding said jointed link mechanism against releasing motion.

15. A fuse construction comprising a pair of spaced stationary contacts, one of said contacts having a substantially vertical pivot member, the other of said contacts having latch means, a fuse tube mounted in a horizontal position, jointed link mechanism adjacent one end of said fuse tube and pivotally supported from said pivot member for supporting said fuse tube for swinging motion in a horizontal plane about said pivot member, said jointed link mechanism normally holding the other end of said fuse tube in latching relation to said latch means, means biasing said fuse tube towards swinging motion, and a fuse link normally holding said jointed link mechanism against releasing motion, said jointed link mechanism being freely removable from said pivot member, whereby said fuse tube may be removed for re-fusing.

16. In an apparatus of the class described, an

electrical device having a meta-1 casing, a metal fuse tube, pivot means supporting said jointed link mechanism and said fuse tube from said second mentioned contact, saidv jointed link mechanism normally holding the free end 'of said fuse tube in latching relation to said latch means, means biasing said fuse tube towards horizontal swinging motion, and a fuse link carried by said fuse tube and holding said jointed link mechanism against releasing motion.

17. In an apparatus of the class described, an electrical device having a metal casing, a metal support supported from and electrically connect` ed to said casing, an insulating bushing extending upwardly from said metal support and having an upper stationary contact, a spaced insulating member carried by said metal support and having a second stationary contact, a fuse tube mounted in a horizontal position and having a free end adjacent said iirst mentioned contact, said iirst mentioned contact including latch means normally holding the free end of said fuse tube, jointed link mechanism adjacent the other end of said fuse tube, pivot means supporting said jointed link mechanism and said fuse tube from said second mentioned contact, said jointed link mechanism normally holding the free end of saidfuse tube in latching relation to said latch means, means biasing said fuse tube towards horizontal swinging motion, a fuse link carried by said fuse tube and holding said jointed link mechanism against releasing motion, and spark gap means between said second mentioned contact and said metal support. c Y v 18. In a fuse construction, a pair of spaced insulating members,- a iirst and a second contact member carried by said insulating members, said iirst contact member havinglatch means including a pair of spring .jaws having divergent outer ends and having a constricted neck portion formed between said jaws, a fuse tube having a free endprovided with ametal cap having a projection normally held by the constricted portion of said latch means, the second of said contact members having a substantially vertical pivot pin, jointed link mechanism supporting said fuse tube from said pivot pin for swinging motion in a horil zontal plane, said jointed link mechanism normally holding said cap in latching engagement withsaid latch means, means biasing said fuse tube for swinging motion about said pivot pin, and a fuse link carried by said fuse tube and normally holding said jointed link mechanism against releasing motion.

19. In a fuse construction, a pair of spaced insulating members, a first and a second contact l member carried by said insulating members, said free end provided with a metal cap having a projection normally held by the constricted portion of said latch means, the second of said contact members having a substantially vertical pivot pin, jointed link mechanism supporting said fuse tube from said pivot pin for swinging motion in a horizontal plane, said jointed link mechanism normally holding said cap in latching engagement with said latch means, means biasing said fuse tube for swinging motion about said pivot pin, a fuse link carried by said fuse tube and normally holding said. jointed link mechanism against releasing motion, said jointed link mechanism being freely removable directly upwardly i'rom said `pivot pin, whereby said fuse ltube may be freely removed for re-fusing.

20. In an apparatus of the class described, an electrical device having a metal casing, an insulating bushing projecting upwardly from said caslng and having an upper contact, an insulator supported from said casing and having an upper contact, an expulsion fuse tube mounted in a horizontal position above said casing, pivot means carried by one of said contacts for pivotally supporting said fuse tube for swinging motion in a horizontal plane whereby the discharge of gases from said expulsion `fuse tube will take place in a horizontal plane above said casing, means biasing said fuse tube toward swinging motion, and a fuse link carried by said fuse tube and normally restraining said fuse tube from swinging motion.

2-1. In an apparatus of the class described, a metal support, an insulating bushing extending upwardly from said metal support and having an upper stationary contact, a spaced insulating member carried by said metal support and having a secondary stationary Contact, a fuse tube mounted in a horizontal position and pivotally supported adjacent one end from one of said stationary contacts and having a free end normally connected to the other of said stationary contacts, means biasing said fuse tube towards horizontal swinging motion, and a fuse link restraining s aid fuse tube from swinging motion.

22. A fuse construction comprising a support having spaced terminals, one of said terminals having pivot means and the other of said terminals having stationary contact means, a fuse tube movable from operative to inoperative position and having one end normally held by said stationary contact means, a lever pivoted on said pivot means and pivoted to said fuse tube and normally positioned adjacent said fuse tube, said lever releasing said fuse tube from said stationary contact means when said lever moves away from said fuse tube, said fuse tube being biased towards inoperative position, a fuse link in said fuse tube normally restraining said lever against releasing motion and electrically connecting said lever and said stationary contact means, and a spring biasing said lever towards said fuse tube after said fuse tube has been released from said stationary contact means.

23. A fuse construction comprising a support, a pair of spaced terminals Ycarried by said support, one of said terminals having vertically arranged pivot means and the other of said terminals having stationary contact means, a fuse tube having one end normally held by said stationary contact means and movable from operative to inoperative position, a lever pivoted on said pivot means and pivoted to said fuse tube, said fuse tube being biasedvtowards swinging motion in a horizontal plane about said pivot means,

said lever normally holding said fuse tube i engagement with said stationary contact means and being normally positioned adjacent said fuse tube, a fuse link within said fuse tube electrically connecting said lever and said stationary contact means s and normally restraining said lever against releasing motion, and a spring biasing said lever towards said fuse tube after said fuse tube has been released from said stationary contact means.

24. A fuse construction comprising a terminal having pivotvmeans, a fuse tube pivoted on said A pivot means and having a free end adapted to swing with reference to said pivot means, a latch carried by said free end. a second terminal havinga catch normally engaged by said latch and ,4 restraining said fuse tube against swinging motion, va fuse link normally restraining said latch against releasing motion and electrically connecting said terminals, and a spring carried by said second terminal and urging said fuse tube against swinging motion.

`25.`A fuse construction comprising a rst terminal having pivot means, a fuse tube pivotally supported from said pivot means and having a free end, said fuse tube being open at each end,

a latch carried by the free end of said fuse tube,

a second terminal provided with a catch normally engaged by said latch, a headed fuse link extending through said fuse tube and electrically connecting said terminals, said fuse link having the head thereof located at the end of the fuse tube adjacent the pivot means and having its other end restraining said latch, and a spring bearing against the headed end of said fuse link and urgi gl said fuse tube towards swinging motion abo t said pivot means.

WILLIAM O. SCHULTZ.

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