US2324114A - Fuse - Google Patents

Description

July 13, 1943.

Y W. 0. SCHULTZ ETAL Fuss Filed July 20, 1939 6 Sheets-Sheet 1 e 5 mum n TL WWW M VC /4 0 m 1 06. A M mw 4w w mh y 3,1943. w. 0. Hum 5m 2,324,114

FUSE

Filed July 20, 19,39

INVENTORS Wilt/AM 0. Jam rz A1 N 6. YJ'IZ-M/MA YEA ATTORJ Z 1943 w. o. SCHULTZ arm. 4 2,324,114

FUS E Filed July 20,1939 6 Sheets-Sheet 5 IN V EN TORS Wu L MM 0. 50/01 rz July 13, 1943, w. o; SCHULTZ ETAL FUSE Filed July 29, 1939 6 SheetsSheet 6 Patented Jul 13, 1943 FUSE William 0. Schultz, South Milwaukee, and Alwin G. Steinmayer, Milwaukee, Wis., asslgnors to Line Material Company, South Milwaukee, Wis a corporation of'Delaware Application July 20, 1939, Serial No. 285,474

39 Claims. (Cl. 200114) 'I'hisinvention relates to fuses and is particularly directed to a high voltage fuse.

Objects of this invention are to provide a novel form of expulsion type fuse whichis so made that although it can be used for high voltage and has, therefore, a relatively great length of tube and a relatively great length of fuse link, nevertheless is so made'that means are provided for withdrawing any remaining portion of the I fuse link when the fuse link is ruptured. When forms of the invention, will be disengaged from the apparatus and allowed to fall clear of the fuse structure so that the hazard to an operator, aswell as the danger of grounding the line,

I will be avoided.

Further objects are to provide a fuse construction which although employing a relatively long and heavy fuse tube together with its associated parts, is nevertheless so made that excessive strains are not imposed on the fuse link, thereby permitting fuse links for relatively small current, capacities if so desired to be used without straining these more delicate fuse links to any dangerous degree.

Further objects are toprovide a double hinge construction, and in the preferred form of the invention, t provide a double lever construction in addition to the double hinge construction, and in all forms of the invention to provide means for substantially supporting the weight of the fuse tube and its associated parts so that though there is a tendency to break the double hinge and thus allow the mechanism at the lower end of the fuse tube to collapse and allow the fuse tube to drop outwardly, nevertheless there is only a very small stress imposed on the fuse link by the weight of the fuse tube and its associated structure due to the arrangement of pivot points of the double hinge construction, the stress on the fuse link being primarily imposed, in certain forms of the invention, by

spring means and being of a predetermined rel- [ativ'ely small value as compared with the weight of the fuse tube and its associated parts.

. In one form of the invention a double lever construction is employed and the fuse link is pulled substantially straight downwardly from the fuse tube. In other forms of the invention this direct downward pull is approximate but occurs at a greater angle than in the first mentioned form.

Further objects are to provide a fuse construction in which adequate means are provided for conducting the current to the upper and lower contact of the fuse tube and from there to the fuse link, so that heating will not occur at these contact parts, and to provide a simple type of upper latch construction which acts as a sleet hood and also which protects the active contact, whether the fuse tube is in open or closed position, thereby preventing the accumulation of snow or the formation of ice on such contact, and to provide substantial housing for the double hinge construction adjacent the lower portion of the device.

Further objects are to provide novel means for securing the fuse link by a snubbing or spring clamping action, such means permitting the release of the fuse link after the fuse link has been extracted from the fuse tube, and such means being provided with thumb pieces or manipulating parts so that they may be easily opened up for the insertion of the fuse link, the clamping portion being thereafter released so that it automatically clamps the fuse link in place.

Further objects are to provide a construction which guards the fuse link against shock or excessive straining due to the rocking of the fuse tube back into closed circuit position after it has been refused, in addition to guarding the fuse link against excessive straining due to the weight of the fuse tube and its parts.

Further objects are to provide a construction whereby the fuse tube and its associated parts may be completely removed from the support and may be refused and replaced by an ordinary switch stick or hook stick and may thereafter be rocked back into service by means of such stick.

More specifically, objects of this invention are to provide a double hinge construction which may be used for a relatively heavy fuse tube and relatively heavy associated parts, and to 'arrange the two main pivot points of the hinge substantially one above the other, spring means being provided, however, to insure the dropping out of the fuse tube and the proper and quick clearing of the device upon overload. This permits the predetermining or regulating of the strain on the fuse link by the proper selection of Embodiments of the invention are shown in the accompanying drawings, in which:

Figure 1 is a view, partly in section, showing one form of the invention.

Figure 2 is a fragmentary sectional view on I the line 2-2 of Figure' 1.

Figure 3 is a view of the lower portion of the apparatus showing in full lines the position of the parts after the fuse has blown and dropped outwardly, and showing in .dotted lines the position of the parts at the early portion of the release of the parts.

Figure 4 is a bottom view of the fuse structure and its associated parts removed from the support.

Figure 5 is a side view of the lower portion of the fuse.

Figure 6 is a fragmentary view showing the lower portion of a further form that the invention may take.

Figure 7 is a fragmentary view of the lower portion of a further form of the invention, such view being partly in section and partly broken away.

Figure 8 is a view looking upwardly at the fuse structure shown in Figure 7 as it appears Figure 10 is a view looking upwardly at the fuse structure shown in Figure 9 as it appears when removed from the support.

Figure 11 is a fragmentary view of the lower portion of a' still further form of the invention,

such view being partly in section.

Figure 12 is a view looking upwardly at the fuse structure shown in Figure 11 as it appears when removed from the support.

Referring to the drawings, particularly the first form of the invention shown in Figures 1 to 5, it will be seen that the device comprises upper and lower contacts which are secured to insulator caps l, in accordance with the usual practice, carried by insulators mounted on a suitable support, not shown. The upper contact 2 is provided with an integral outwardly projecting sleet hood 3. Beneath the sleet hood a relatively heavy contact spring 4 is provided which is adapted to bear on the upper contact of the fuse tube. It has an upwardly turned portion 5.

A latching lever 6, which may be of U-shape, is positioned under the hood 3 and is provided with an upwardly slanting, transverse web or cam portion 'l'that is adapted to be deflected upwardly by the upper contact of the fuse tube when the fuse tube is rocked into place and to thereafter drop downwardly to lock the fuse tube against outward motion, as shown in Figure l.

The contact spring 4 is securely bolted to the contact 2 and the latch 6 is carried by a pin 8 mounted transversely in the sleet hood 3. A spring 9 is provided which bears at one end against a transverse pin [0 carried by the sleet hood 3. This transverse pin also acts as a stop 7 to limit the inward motion of the inwardly rocking fuse tube. The spring has its other end booked and bearing against one of the downwardly projecting legs ll of the latch 6.

hood l3 and has a pair of spaced, upwardly extending supporting hooks M which receive the trunnions of one of the leversattached to the fuse tube and hereinafter described. A heavy contact spring I5 is also secured to the lower contact l2 and is adapted to engage a project-. ing portion ofthe lower structure of the fuse tube to provide adequate electrical contact for a portion of the lower contact of the fuse tube.

0 This spring I5, as will hereinafter appear, is'the primary agent for imposing tension on the fuse link and consequently by the judicious selection of the spring, the requisite tension may be secured, irrespective of the weight of the fuse tube and its associated parts, for, as will hereinafter appear, most of this weight is borne directly by the supporting structure and only a very light tension is imposed on the fuse link due tothe weight.

The fuse tube I6 is relatively long and heavy, if it is to be used for high tension work, though, of course, the device may beused for a lower voltage if so desired. For high tension work, the whole structure is also relatively long, that is to contacts is relatively great and, of course, the

fuse linkincluding its leader is necessarily relatively long.

The fuse tube is provided with an upper contact consisting of a ferrule ll which may be screw-threaded on the fuse tube and may have a split portion drawn together by a screw or bolt l8 to securely clamp the ferrule in place on the fuse tube. This ferrule has an upwardly projecting, reduced threaded portion which receives the upper contact cap I9 of the fuse tube.

This upper contact cap has a flat upper face which flatly engages the relatively heavy contact spring 4. The lower portion of the fuse tube is provided with a casting 20 which may have a split ordivided rear portion drawn together by a bolt 2| into clamping engagement with the fuse tube Hi. It is preferable to slightly notch the fuse tube l6 at the bolt, the bolt being set slightly within the outline of the fuse tube, as shown in Figure 1. This casting 20 is provided with outwardly projecting arms 22 and an outwardly projecting portion 23 which may be engaged by a switch hook or switch stick to lift the fuse into position after it has been refused, the switch hook later being placed in engagement with the eyelet portion 24 to rock the fuse tube into closed position, Preferably the member 22 is forked, as shown most clearly in Figure 5, and the member 23 is provided with an opening therethrough, as shown by the broken away portion of Figure 1, to allow the use of a switch stick in manipulating the fuse tube. The projecting portion 23 of the casting 20 is also utilized as a support for the pin 25 upon which one element 26 of latching means is pivoted. This element of the latching means or first latch portion is urged by means of the spring 21 towards clockwise rotation as viewed in Figure 1, and has a downwardly extending lower portion provided with an aperture 28 for a purpose hereinafter to appear.

One end of the lower part of the latch member 28 is extended to provide a thumb manipulating member 29, and the other end is extended to provide a snubbing or binding portion 30, see Figures 1, 2 and 5. The latch member, 26 is provided with an inwardly projecting web or stop 3!, see Figure 1, which limits the inward rocking mo- The lower contact I2 s Pr vi e w a $1961; tion of the latch member when the latch member is provided with an abutment or upwardly extending portion 36. The abutment 36 normally contacts the bottom end of the fuse tube as shown in Figure l but does not act to support the fuse tube, the support being through the pivot points 34 and 35. After the fuse tube has dropped outwardly. the abutment 38 again contacts the lower end of the fuse tube and thus provides a stop for arresting the downward rocking motion of the fuse tube, a portion of the lever 33 also contacting the lower terminal member I 2 as shown in Figure 3. This provides for the direct transmission of the force through the abutment 36 and lever 33 to the lower terminal l2 when arresting the tube at its lowest position as shown in Figure 3.

The outer end of the lever 33 carries a transverse pin 31. A link withdrawing member indicated generally at 33 is pivotally mounted on the pin 31. It is provided with a pair of hubs-positioned on opposite sides of the lever .33, as shown most clearly in Figure 2.

One of the hubs is relatively large and is indicated at 39 and provides one part of a snubbing portion between which the leader of the fuse link 49 is clamped, the fuse link as usual being composed of the leader portion and an upper fusible portion 4|. The other hub 42 may be relatively small.

The link withdrawing member 38 has a relatively long arm extending in the form of an arch to a position beneath the lower end of the fuse tube, as shown in Figures 1 and 2. This curved arm is provided with an upper flange 43 and a lower portion 44 about which the fuse link is wrapped or passed; as shown in Figures 1, 2 and 4, the fuse link being positioned beneath the flange and extending upwardly over the enlarged hub or snubbing portion 39. It is to be noted from Figure 2, that the portion 30 of the first It is to be noted that when the fuse link blows and the parts operate aswill hereinafter be described, that there is a true rolling action of the snubbing portionwith reference to the adjacent part 30 of the fuse link clamping mechanism and consequently there is no friction at this point during the operation of the device.

The fuse link withdrawing member 38 also constitutes a second latch member or latch portion. It is provided with an outwardly extending tongue 45, see Figures 1, 2 and 5, which extends through the opening 28 of the first latch member 33 and is held by the latch member.

The contact spring ii of the lower terminal I2 bears against projecting portions 46 of the lever 33 and urges the lever towards rocking motion in a clockwise direction as viewed in Figure 1,

and also provides an adequate electrical contact between the lower terminal of the fuse tube, that is to say, the lever 33, and the stationary terminal l2. It also stressesthe fuse link a predetermined amount, for it tends to rock the lever 33 in a clockwise direction, as stated, and this motion is resisted by the coaction of the latching members 23 and 38. The outer end of the lever 33 tend to rock downwardly and consequently the free end or inner end of the fuse link extracting member and latch member 38 tends to move downwardly, and, upon rupture of the fuse link, will quickly withdraw any remaining portion of the fuse link although the fuse link may be relatively long for high voltage fuses.

It is also clear that upon rupture of the fuse link, the lever 33 moves downwardly primarily under the influence of the spring I3 and at the same time the fuse link extracting member 33 pivots about the pin 31 and thereby execute a rocking motion, and the combination of these two motions causes the fuse link to be drawn downwardly substantially in direct line with the fuse tube. It is to be noted that the pivot points 34 and 33 are almost directly above each other and consequently very little stress is imposed on the fuse link due to the weight of the fuse tube and its associated parts. If desired, the pivot point 34 may be directly above the pivot point 33.

Upon continued motion of the parts, for example beyond the dotted line position shown in Figure 3, the fuse link is released from the combined clamping action of the two latching members 38 and 29 and is entirely freed from the device and is thrown or dropped downwardly. The parts finally assume the full line position shown in Figure 3 with the fuse tube out of circuit.

It will be seen from a comparison of Figures 1 and 3 that the fuse link is very quickly withdrawn and this occurs before the fuse tube has rocked out of circuit and consequently the circuit is interrupted within the fuse tube prior to the moving away of the upper contact of the fuse tube from the upper stationary contact. In the form shown there is a slight downward motion of the fuse tube during the actual withdrawing of the fuse link but the contact spring 4 at the upper end of the device, see Figure l, maintains contact with the upper contact of the fuse tube during this interval.

It is to be noted also that the compound lever construction formed of the levers 33 and 38 cause the motion of the parts to be multiplied so that the fuse link is extracted with a very quick movement and attains a high velocity in a downward direction. Subsequent release of the fuse link as described hereinabove allows the fuse link to continue downwardly completely away from the device.

It is to be noted from Figure 1 that the pivot pins or trunnion members 34 and 35 are mounted almost directly one above the other so that although the fuse tube may be relatively long and, together with its associated parts, may be relatively heavy, nevertheless dangerous stresses are not imposed on the fuse link. Instead, by properly selecting the spring IS, the exact desired tension on the fuse link may be obtained as this tension, as stated hereinabove, is practically unaffected by the weight of the parts.

The fuse tube may be removed from the stationary portion of the apparatus if desired while the fuse link is intact. This is readily accomplished by pulling downwardly on the pivotally mounted eyelet 24, such eyelet portion being carried by a pivot pin 41' carried by the portion ll of the upper contact, a spring 48 being provided to normally hold the eyelet memher 24 in its upper position as shown. This member 24 is bifurcated and has the two arms 49 located on opposite sides of the upper portion of the fuse tube and in engagement with a pair of downwardly extending arms 60 stress, does not materially affect the fuse link.

It is to be noted for instance, that when the cap or top contact of the fuse suddenly engages the latch 6 and thereafter the spring contact 4 when the fuse tube is being rocked into service or operative position, that this suddenly applied,

downward force does not materially affect the tension on the fuse link itself.

When the fuse link is ruptured, the member 38 is released and rocks about the pin 31, allowing the tongue 45 to disengage itself from the latch member 26. However, the fuse link is still clamped during a portion of the releasing motion and at the same time the second latching member or fuse link withdrawing member 38 rocks downwardly at a very rapid rate and also the lever 33 rocks downwardly, thus very quickly withdrawing the fuse link. Obviously, if the overload is severe, the expulsive action in the tube itself cooperates to discharge the link. On the other hand, if the overload is a very small one, it may happen that there is a long portion of the fuse link remaining intact. This, however, does not interfere at all with the operation of the apparatus, as the device 'is so made, as described hereinabove, that the remaining portion of the fuse link, whether long or short, is easily and quickly withdrawn and completely discharged from the device. It is to be noted that the free end of the member 38 enters a cut-out portion of the lever 33, as shown in Figure 2.

it is also to be noted that as the lever 33 rocks donwwardly, the pivot point or pivot pin 34 moves to the right, as viewed in Figure l, and takes the successive positions shown in Figure 3, thus lowering the fuse tube and rocking the lower end outwardly a slight distance and allowing the upper end of the fuse tube to detach itself from tne upper latch, and thereafter allowing the tube to drop outwardly to the full line position shown in Figure 3. I

In refusing the device, the lineman takes the hook stick or switch stick and removes the fuse from the lower support. Thereafter he refuses it by removing the upper cap, placing a. new fuse within the tube, replacing the upper cap,

' and drawing the fuse link around the portion 44 of the member 38, such fuse link passing below the flange 43 as described. The lineman then presses his thumb against the portion 29, see Figure 2, and rocks the first latch member 26 outwardly and draws the leader of the fuse link between the snubbing portion 39 and the portion 30 of the latch 26, see Figures 1 and 2, thereafter releasing the first latch member 26. Thereafter he again attaches the fuse tube to the hook stick, lifts the refused fuse tube into position, placing the trunnions 35 within the hook supports l4. He then disengages the hook stick and engages it with the eyelet portion 24 and rocks the fuse tube back into service. The upper and lower terminal members 2 and i2 may be provided with any suitable means for clamping conductors thereto, for example as shown in the lower portion of Figure 3.

It is apparent that if desired, the fuse link could be retained by the apparatus, although this is not the preferred'form. For example as shown in Figure 6, the fuse tube 5| may be provided with a lower casting 52 to which the fuse link extracting lever 53 ispivotally joined by means of the pin 64, such lever 53 being provided with the trunmons 55 and the contact portions 66. The lever 63 is provided with a laterally extending flanged portion 61 and with a clamping screw 68, so that the leader 69 may be clamped beneath the flange 51 as shown. In this case the fuse link is not dropped from the apparatus after the fuse hasblown.

In the form of the invention shown in Figures 7 and 8, the lower support is provided with the hook supporting members 60, as previously described, which receive the trunnions 6| of the main lever 62. This main lever is pivotally joined to a downwardly extending arm 63 of the lower casting 64 which is attached to the lower end of the fuse tube 65. This lower casting is provided with the upper and lower switch stick receiving portions 66 and 61 so that the device may be manipulated by the switch stick as previously described.

The upper portion of the device may be as described in connection with Figure 1. The lever 62 is provided with a transverse web 68 and with an intermediate transverse web 69. At its rear portion the lever 62 widens laterally, as shown most clearly in Figure 8, so that the side walls 10 are spaced apart a greater distance than the body of the lever. These side walls carrying the integral trunnions 6i. The-rear portion of the lever is provided with curvedfianges H and with a transversely extending portion 12 that Joins the rear side wall 10. I

The arm 63 of the lower casting 64 is in reality bifurcated, or, in other words, constitutes two arms, as shown in Figure 8, and these arms are provided with laterally extending hubs 13 which are in juxtaposition to the side walls 10 of the lever 62. These hub portions may continue only approximately half way around, as shown in Figure 7, and may operate primarily as spacer members to keep the lever 62 properly centered.

The side walls I0 of the fuse link extracting lever or main lever 62 carry a pivot pin 14 which pivotally joins the lever 62 with the lower portion of the bifurcated arm 63. The arm 63, however, is provided with slots 15, as shown in Figure 7, so that there may be a slight relative vertical motion between the lever 62 and the arm 63.

The side walls ill of the lever 62 are joined to the main body of the lever by means of the curved walls 16. with outwardly projecting portions ll on opposite sides thereof so that the leader 18 of the fuse link may be clamped between either of such outwardly projecting portions 11 and the corresponding side wall 16 of the lever 62. A tension spring 19 is secured, as indicated at 80, to the 7 arm 63 of the casting 64 at its upper end and The arm 63 is also provided the parts together and clamp the leader 18 of the fuse link. It is obvious, however, that when the fuse blows, that the outward rocking motion of the lever 62 will finally release the leader and allow the fuse link to be thrown or discharged from the device.

It is to be noted further that the lever 62 is provided with an upper stop portion 8| which abuts the lower end of the fuse tube and is also provided with a pair of hook like outwardly extending arms 82 around either of which the fuse link is passed so that the lower end of the fuse link may be secured at either side of the device. This will be apparent from an examination of Figure 8.

A latch member 83 is pivotally mounted upon the pin 84, see Figure '7, which pin is carried by the arm 63. A spring 85 urges the latch member 83 towards releasing position, tending to withdraw the lower hook portion thereof from engagementbeneath the web 69 of the lever 62. However, motion of this latch means is prevented by one or the other of the two side lugs 86 which are integral with the latch member 83 and which bear downwardly upon the intermediate portion of the leader 18 of the fuse link between its clamped portion and between the point where it passes around the guides or portions 82 of the lever 62.

It is apparent from the above description that when the fuse blows, the latch may now release and allow the lever 92 to rock downwardly and allow the, tube to rock out of operative position into inoperative position as previously described.

As stated, the upper end of the apparatus may be as described in connection with Figure l, and the downward pressure from the relatively heavy upper contact spring, together with the weight of the parts, may be relied upon to give sufdcient contact pressure between the relatively heavy trunnions iii and the hooks to of the lower sup port. It is obvious, however, that if desired, a contact spring may be provided for engaging the lower contact portion oi the fuse tube though none is shown in Figure I.

In refusing the device, the fuse tube is re-= moved from the support as described, and a new fuse link is inserted in the-fuse tube. The lever ti is forced downwardly slightly against the action of the spring 19, the trunnions or pins lid sliding within the slot '55, see Figure l, and the leader of the fuse link is positioned between one of the rounded walls it and the corresponding projecting portion ll of the lower casting. Thereafter the operator releases the parts and allows the spring iii-to cause gripping oi the fuse link. Subseqeuntly the operatorreplaces the fuse as described in connection with Fig== ure 1.

It is to be noted that the fuse link is relieved of all stress due to the weight the fuse tube and its associated parts and from the downward pressure of the upper spring contact, and from all shock due to the sudden closing or rocking of the fuse tube back into service.

in the form of the invention shown in Figures s and 10, the fuse tube ill is provided with a lower casting 88 having the hook stick receiving portions 89 and 9t and the bifurcated arm 96. The arm 9i continues downwardly, as shown in Figure 9, and the two portions thereof are joined adjacent their lower end and project outwardly to form hub portions 92, see Figure 10.

These hub portions carry a transverse pin 99 which is pivotally joined to the main lever or fuse link extracting lever 94. The lever 94 is provided with a front web portion 95 and with an intermediate web portion 96 which constitutes a latch. The rear part of the lever 94 widens outwardly to provide the spaced side walls 91 which carry the integral trunnions 98, which latter are removably received in the hook supports 99. The rear side walls 91 are joined to the body of the lever by curved walls I00. A transverse pin IOI, see Figure 9, extends through the two portions of the arm 9| and a latch member I02 is pivotally carried by the pin I III and hooks beneath the latch web 96 of the main lever or fuse extracting lever 94.

A spring I03 urges the latch I02 towards releasing position. The latch also carries a pair of wings or projecting portions [04 which hear I on the intermediate portion of the leader I05 of the fuse link. The lever 94 is provided with projecting hook like portions I06, see Figures 9 and 10, about which the fuse link, is looped, the outer end of the fuse link being held in gripping relation with one or the other of the curved side walls I90 by means of a U-shaped lever I91 provided with bearing portions I98 which bear downwardly on the leader of the fuse link. The lever I0? is urged into clamping engagement with the fuse link by means of the spring H19 and is pro vided with a thumb piece H0 which may be engaged by the thumb of the operator during refusing to raise the lever and allow the fuse link to be positioned between one or the-other oi the feet tilt! and the corresponding curved side wall WU of the main lever or fuse link extracting lever 94.

When the fuse link is ruptured, the latch W2 is released and the lever 9d rocks to fuse link extracting position and withdraws any remaining portion of the fuse link from the fuse tube. The fuse link is finally detached from the device and allowed to drop or be thrown free of the apparatus.

In this form of the invention no strain is im= posed on the fuse link due to the weight of the tube and the associated parts, or due to the downward pressure of the upper contact spring. The downward pressure of the upper contact spring, together with the weight of the fuse tube and associated parts, insures adequate contact pressure between the hooks 99 and the trunnions though if desired a lower contact spring could be provided and could bear against an appropriate portion of the lower part of the device, for example against the portion its similarly to that illustrated in Figure 11.

In the form of the invention shown in Figures ii. and 12, the fuse tube iii is provided with a lower casting M2 which has the hook stick receiving portions M3 and EM and which has a bifurcated downwardly extending arm H5. This arm is provided adjacent its lower portion with laterally extending hubs i it which carry a transverse pin iii.

A main lever or fuse link extracting lever H8 is pivotally joined to the pin i ill and is provided with spaced side walls i W adjacent its rear end which are integrally formed with trunnions 52d adapted to be seated within the hook supports 426. This main lever is, as previously described in connection with the form of the invention shown in Figures 7 and 8, provided with laterally extending portions 2122 about which and under which the leader 2'23 of the fuse link extends.

The leveri i8 i provided with a front web 826 which Joins the front side walls thereof and with an intermediate latching web I25. This latching web I 25 is engaged by the latch l 26, such latch being pivotally mounted on a pin I21 and urged by means of the spring I28 towards latch releasing position. The latch carries a pair of outwardly projecting wings or arms E29 which bear on the intermediate portion of the fuse link and which thereby restrain the latch from releasing motion until the fuse link is ruptured. The main lever or fuse link extracting lever M8 is provided with curved walls E30 which join the rear side walls N9 of the main body of the lever.

A U-shaped lever fat is pivotally mounted on the pin i2? and is urged downwardly by means of the spring I32. It is provided with laterally extending portions E33 between either of which and the corresponding curved wall i311 of the lever I i8 the fuse link i 23 is adapted to be clamped, the fuse link being finally released and thrown or dropped from the device.

The lever l3! continues rearwardly to provide a' thumb piece and contact engaging part 936. The lever may be raised during refusing by the operator's thumb bearing against the part 534.

However, the part id l has the additional function of firmly engaging the lower contact spring I35.

This form of the invention operates in substantially the same manner as described in connectionwith Figure 9, the fuse link being extracted by the lever H8 and being finally released and thrown or dropped from the device.

In refusing, a new fuse link is inserted in the fuse tube and clamped between the parts I30 and E33. Thereafter the fuse tube is mounted on a hook stick and replaced and thereafter rocked into operative position.

No strain is imparted to the fuse link due to the weight of the fuse tube and its associated parts or due to the upper contact spring. The upper construction of the device may be as described in connection with Figure 1.

It will be seen that novel forms of fuse construction have been provided by this invention which may be used for high voltage work if so desired, and in which the fuse tubes may be made as long as desired and the parts may be as heavy as need be'without imposing any undue strains on the fuse link. Further the contact pressure of the contact parts may be as heavy as needed, also without unduly straining the fuse link, and, in certain forms of the invention, without imposing any strain on the fuse link whatsoever due either to the weight of the parts or the pressure of the contacts. Inall forms of the invention, however, no material stress is imposed on the fuse link due to the weight and the contact pressure.

It will be seen further that the device may be easily removed from the fixed supports and refused and restored by means of a hook stick, the refusing being performed While the fuse tube is completely removed from the supports.

It will be seen further that although a long link may. be employed, nevertheless the device is so made that a complete extraction of the link is obtained.

Although this invention has been described 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.

We claim:

1. A drop out fuse construction 'ccmprising a support having upper and lower stationary contacts, latch means adjacent the upper contact, a-

fuse tube normally positioned between said contacts and restrained by said latch means, said fuse tube having a closed upper end and a open lower end, a fuse link extending through said fuse tube and electrically joining said upper and lower stationary contacts, a main fuse link extracting lever pivoted to said lower stationary contact, an arm carried'by said fuse tube and pivoted to said main lever' and adapted to be,displaced downwardly when said main lever rocks downwardly, and latching means including an auxiliary lever normally restraining th motion of said main lever, said fuse link being looped over said auxiliary lever, whereby when said fuse link is ruptured said main and auxiliary levers w ll withdraw any remaining portion of the fuse link downwardly from said fuse tube and said fuse tube will move downwardly and outwardly.

2. A drop-out fuse construction comprising a support having upper and lower stationary contacts, latch means adjacent the upper contact, a fuse tube normally positioned between said contacts and restrained by said latch means, said fuse tube having a closed upper end and an open lower end, a fuse link extending through said fuse tube and electrically joining said upper and lower stationary contacts, a main fuse link extracting lever pivoted to said lower stationary contact, an arm carried by said fuse tube and pivoted to said main lever and adapted to be displaced downwardly when said main lever rocks downwardly, and latching means including an auxiliary lever for normally restraining the motion of said main lever, said fuse link being looped over said auxiliary lever, said auxiliary lever having a free end extending inwardly and positioned adjacent the lower portion of said fuse tube and movable substantially directly downwardly with reference to said fuse tube.

3. A drop-out fuse construction comprising a support having upper and lower stationary contacts and having upper latch means and a lower pivot support means, an expulsion type fuse tube having a closed upper end provided with a contact normally engaging the upper stationary contact and normally restrained by said upper latch means, a main fuse link extracting lever pivotally supported from said lower pivot means at a point offset with reference to said fuse tube and pivotally joined to said fuse tube, an auxiliary fuse link extracting lever pivoted adjacent the outer end of said main lever and having a free inner end positioned adjacent the lower portion of said fuse tube, said auxiliary lever having means about which saidfuse link is looped, and latch means including a portion of said auxiliary lever for normally latching said main and auxiliary levers against motion to normally hold said fuse tube in operative position.

4. A drop-out fuse construction comprising a support having upper and lower stationary contacts and having upper latch means and a lower pivot support means, an expulsion type fuse tube having a closed upper end provided with a contact normally engaging the upper stationary contact and normally restrained by said upper latch means, a main fuse link extracting lever pivotally supported from said lower pivot means at a point offset with reference to said fuse tube and pivotally joined to said fuse tube, an auxiliary fuse link extracting lever pivoted adjacent the outer end of said main lever and having a free inner end positioned adjacent the lower portion of said fuse tube. said auxiliary lever having means about which said fuse link is looped, latch means including a portion of said auxiliary lever for normally latching said main and auxiliary levers against motion to normally hold said fuse tube in operative position, and snubbing means for frictionally holding the lower end of said fuse link.

5. A drop-out fuse construction comprising a support having upper and lower stationary contacts and having an upper latch means and a lower pivot support means, a fuse tube having a closed upper end and an open lower end, a fuse link within said fuse tube normally electrically joining said upper and lower stationary contacts and extending outwardly of the lower open end of the fuse tube, a main fuse link extracting lever having trunnion supported by said pivot support means, an arm rigid with said fuse tube and offset laterally therefrom and pivoted to said main lever at a point spaced upwardly above said trunnions, an auxiliary fuse link extracting lever pivoted to said main lever adjacent the outer end of said main lever and over which said fuse link is looped, said auxiliary lever having a projecting portion, a spring urged member coacting with said projecting portion and forming therewith latch means, and mean for holdin the lower portion of said fuse link looped around said auxiliary lever, whereby when said fuse link is ruptured, said auxiliary lever will rock and release said latch means and thereby release said main lever, whereby said fuse tube will move downwardly from said latch and will rock outwardly,

6" A drop-out fuse construction comprising a support having upper and lower stationary contacts and having an upper latch means and a lower pivot support means, a fuse tube having a closed upper end and an open lower end, a fuse link within. said fuse tube normally electrically joining said upper and lower stationary contacts and extending outwardly of the lower open end of the fuse tube, a main fuse link extracting lever having trunnions supported by said pivot support means, an arm rigid with said fuse tube and off set laterally therefrom and pivoted to said main lever at a point spaced upwardly above said trun nions, an auxiliary fuse link extracting lever pivoted to said main lever adjacent the outer end of said main lever and over which said fuse Link is looped, said auxiliary lever having a projecting portion, a spring urged member coacting with said projecting portion and formin therewith latch means. and means for holding the lower portion of said fuse link looped around said aux-= iliary lever, whereby when said fuse link is ruptured. said auxiliary lever will rock and release said latch means and thereby release said main lever, whereby said fuse tube will move downwardly from said latch and will rock outwardly, the combined motion of said main and auxiliary levers causing the free end of said auxiliary lever to move substantially directly downwardly from the lower end of said fuse tube. I

7. A drop-out fuse construction comprising a support having upper and lower stationary contacts, said lower contact having a pair of outwardly projecting hook like members, said upper contact having a latch, an expulsion type fuse tube normally restrained from rocking motion by said latch and having an upper contact normally engaging said upper stationary contact, said fuse tube having an open end fuse link extending through said fuse tube from said upper contact outwardly through the lower open end thereiii of, a main fuse link extracting lever having trunnions pivotally supported by said hook like members, an arm offset with reference to said tube and extending downwardly therefrom and rigidly carried by said tube and having pivotal connection with said main lever at a point above said trunnions, an auxiliary fuse link extracting lever having a free end over which said fuse link is looped and having a hub portion, a latch member supported from said fuse tube and spring pressed inwardly towards said hub portion and gripping the fuse link between said hub portion and said latch member, and latch means carried by said auxiliary lever and coacting with said latch membar.

8. A-drop-o1zt fuse construction comprising a support having upper and lower stationary contacts. said lower contact having a pair of out wardly projecting hook like members, said upper contact having a latch, an expulsion type fuse tube normally restrained from rocking motion by said latch and having an upper contact normally engaging said upper stationary contact, said fuse tube having an open end, a fuse link extending through said fuse tube from said upper contact outwardly through the lower open end thereof, a main fuse link extracting lever having trunnions pivotally supported by said hook like members, an arm offset with reference to said tube and extending downwardly therefrom and rigidly carried by said tube and having pivotal connection with said main lever at a point above said trunnions, an auxiliary fuse link extracting lever having a free end over which said fuse link is looped and having a hub portion, a latch member supported from said fuse tube and spring pressed inwardly towards said hub portion and gripping the fuse link between said hub portion and said latch member, latch means carried by said auxiliary lever and coacting with said latch member, and a contact spring carried by said lower contact and engaging said main lever.

9. A drop-out fuse construction comprising a support having upper and lower stationary contacts, an expulsion type fuse tube normally electrically joining said upper and lower contacts and including a fuse link, an upper retaining member releasably engaging said fuse tube, main lever means pivoted with respect to said fuse tube and pivoted upon said lower stationary contact, auxiliary lever means controlled by said fuse link and pivoted to said main lever means, said auxiliary lever means having a projecting tongue, and latch means coacting with said projecting tongue to hold said main and auxiliary lever means against motion while said fuse link is intact and releasable upon rupture of said fuse link.

10. A drop-out fuse construction comprising a support having upper and lower stationary contacts, an expulsion type fuse tube normally electrically joining said upper and lower contacts and including a fuse link, an upper retaining member releasably engaging said fuse tube, main lever means pivoted with respect to said fuse tube and pivoted upon said lower stationary contact,

auxiliary lever means controlled by said fuse link and pivoted to said main lever means, said auxiliary lever means having a projecting tongue, and latch means coacting with said projecting tongue to hold said main and auxiliary lever means against motion while said fuse link is intact and releasable upon rupture of said fuse link, a portion at least of said latch means and said auxiliary lever means forming snubbing means for gripping the projecting portion of said fuse link.

11. A drop-out fuse construction comprising a support having upper and lower contacts, said upper contact having a sleet hood, a contact member mounted below said sleet hood and a latch mounted below said sleet hood, said lower contact including a sleet hood and pivot supporting means, an expulsion type fuse tube normally restrained from motion by said latch and including a fuse link electrically connecting said upper and lower contacts, said fuse tube having a laterally projecting arm extending downwardly below the sleet hood of said lower contact, a main lever pivotally joined to saidarm and pivotally supported from the pivot supporting means of said lower contact and extending laterally below said fuse tube, an auxiliary lever pivotally mounted adjacent the outer end of said main lever and having a free end positioned below said fuse tube and about which said fuse link is looped, said auxiliary lever having a laterally projecting tongue and having a hub portion, and a spring pressed apertured lever receiving said laterally projecting tongue and gripping the projecting portion of said fuse link between itself and the hub portionof said auxiliary lever.

12. A drop-out fuse construction comprising a support having upper and lower contacts, an expulsion type fuse tube including a fuse link normally electrically connecting said upper and lower contacts, said fuse link projecting outwardly from said fuse tube, a main lever pivotally supported from the lower contact and pivotally supporting said fuse tube, said fuse tube dropping outwardly when said main lever rocks downwardly, and latch means having a portion normally frictionally holding said fuse link, said latch means normally restraining said main lever against motion, said latch means being released upon ruptureof said fuse link and releasing the fuse link.

13. A drop-out fuse construction comprising a support having upper and lower contacts, an expulsion type fuse tube including a fuse link normally electrically connecting said upper and lower contacts, said fuse link projecting outwardly from said fuse tube, a main lever pivotally supported from the lower contact and pivotally supporting said fuse tube, said fuse tube dropping outwardly when said main lever rocks downwardly, and latch means having a portion normally frictionally holding said fuse link, said latch means normally restraining said main lever against motion, said latch means being released upon rupture of said fuse link and releasing the fuse link, said latch means having an operative interlock with said main lever.

14. A drop-out fuse construction comprising a support having upper and lower contacts, an expulsion type fuse tube including a fuse link normally electrically connecting said upper and lower contacts, said fuse link projecting outwardly from said fuse tube, a main lever pivotally supported from the lower contact and pivotally supporting said fuse tube, said fuse tube dropping outwardly when said main lever rocks downwardly, and latch means having a portion normally frictionally holding said fuse link, said latch means normally restraining said main lever against motion, said latch mean being released upon rupture of said fuse link and releasing the fuse link, said latch means including mechanically interlocking parts. I

15. A drop-out fuse construction comprising upper and lower contacts, a fuse tube including a fuse link normally electrically connecting said upper and lower contacts, a main lever pivotally supporting said fuse tube, said fuse tube dropping outwardly when said lever moves downwardly, said fuse link projecting outwardly from the lower portion of said fuse tube, and snubbing means for gripping th projecting portion of said fuse link, said snubbing means including means carried by said main lever and releasing said fuse link when said fuse link is ruptured.

16. A drop-out fuse construction comprising upper and lower contacts, a fuse tube including a fuse link normally electrically connecting said' upper and lower contacts, a main lever pivotally supporting said fuse tube, said fuse tube dropping outwardly when said lever moves downwardly, said fuse link projecting outwardly from the lower portion of said fuse tube, and snubbing means for gripping the projecting portion of said fuse link, said snubbingmeans including means carried by said main lever and a spring pressed member coacting with the means carried by said main lever. k l

1'7. A drop-out fuse construction comprising a support having upper and lower contacts, an expulsion type fuse tube including a fuse link normally electrically connecting said upper and lower contacts, said fuse link projecting outwardly from said fuse tube, a main lever pivot,

ally supported from said lower contact, means rigid with the lower portion of said fuse tube and pivotally joined to said main lever, said main 1ever pivotally supporting said fuse tube-and said fuse tube dropping outwardly when said main lever rocks downwardly and latch means controlled by said fuse link and having two portions one of which is carried by the means rigid with the lower portion of said fuse tube and the other of which is movably carried by said lever, said latch means restraining said main lever against motion until said fuse link is ruptured.

18. A drop-out fuse construction comprising a support havingupper and lower contacts, a fuse tube having a fuse link therein normally electrically joining said upper and lower contacts, a member rigid with the lower portion of said fuse tube and projecting therefrom, a lever pivoted on said rigid member and pivotally supported from 19. A drop-out fuse construction comprising a support having upper and lower contacts, a fuse tube having a fuse link normally electrically connecting said upper and lower contacts, a lever mounted adjacent the lower portion of said fuse tube and pivotally supported from the lower contact, said lever normally'holding said fuse tube in operative position'and releasing said fuse tube for drop-out motion when said lever moves downwardly, latch means supported from said fuse tube and having latching engagement with said lever, said latch'means having a portion bearing against said fuse link and released when said fuse link is ruptured and said lever having means bearing against said fuse link for extracting said fuse link.

20. A drop-out fuse construction comprising a support having upper and lower contacts, a fuse tube having a fuse link normally electrically connecting said upper and lower contacts, a.

lever mounted adjacent the lower portion of said fuse tube and pivotally supported from the lower contact, said lever normally holding said fuse tube in operative position and releasing said fuse tube for drop-out motion when said lever moves downwardly, said lever having means bearing against said fuse link for extracting said fuse "contacts, a main lever pivotally Supported from said lower contact and normally holding said fuse tube in operative position, said lever releasing said fuse tube for drop-out motion when said lever moves downwardly, latching means biased towards latch releasing motion and supported from said fuse tube and latching said lever in operative position, and automatically releasing gripping means for holding said fuse link at a point spaced from the lower end of said fuse tube, said latching means having a portion hearing against an intermediate part of said fuse link and said gripping means releasing said fuse link when said fuse tube has dropped out.

22. A drop-out fuse construction comprising upper and lower stationary contacts, a fuse tube having a fuse link normally electrically connecting said stationary contacts, said fuse link projecting out of the lower end of said fuse tube, a lever pivotally mounted on said lower contact and having a portion normally engaging said fuse link, snubbing means spaced from the fuse link engaging portion of said lever, a latch normally latching said lever in an upper position, said latch being spring biased towards releasing motion, said lever being movable downwardly to release said fuse tube for drop-out motion, said latch having a portion bearing against said fuse link between the fuse link engaging portion of said lever and the fuse link snubbing portion.

23. A drop-out fuse construction comprising upper and lower contacts, a fuse tube having a fuse link electrically joining said contacts, a lever pivotally supported from the lower contact, an arm rigid with the lower portion of said fuse tube and pivoted to said lever, said lever normally being in an elevated position and having downward motion to release said fuse tube for drop-out motion, said lever having a fuse link extracting portion adjacent said fuse tube and having a fuse link gripping portion spaced from said fuse link extracting portion; means carried by said arm and spring pressed towards said fuse link gripping portion to grip said fuse link, a latch pivoted to said arm and having a latch portion positively interlocking with said lever, spring means for biasing said latch towards releasing motion, and means carried by said latch and engaging said f-use link between said fuse link extracting portion and said fuse link gripping portion.

24. A drop-out fuse construction comprising upper and lower stationary contacts, a fuse tube having a fuse link normally electrically joining said contacts, a lever pivoted on said lower contact and having a fuse link extracting portion adjacent said fuse tube and having a fuse link engaging portion spaced from said fuse link extracting portion, said lever normally occupying an elevated position and being movable downwardly to release said fuse tube for drop-out motion, an arm rigid with the lower portion of said fuse tube and having pivotal and slidable connection with said lever and having a fuse link engaging portion cooperating with said first mentioned fuse link engaging portion to grip said fuse link, spring means urging said fuse link engaging portions towards each other, and a latch spring biased towards open position and normally locking said lever in elevated position, said latch having a portion bearing against said fuse link intermediate the said fuse link engaging portions and the fuse link extracting portion.

25. A drop-out fuse construction comprising upper and lower stationary contacts, a fuse tube having a fuse link normally electrically joining said contacts, a lever pivoted on saidlower contact and having a fuse link extracting portion adjacent said fuse tube and having a fuse link engaging portion spaced from said fuse link extracting portion, said lever normally occupying an elevated position and being movable downwardly to release said fuse tube for drop-out motion, an arm rigid with the lower portion of said fuse tube and pivoted to said lever, a spring pressed fuse link engaging lever having a fuse link engaging portion cooperating with said first mentioned fuse link engaging portion for gripping said fuse link, and a latch spring biased towards open position and normally positively latching said lever in elevated position, said latch having means engaging said fuse link intermediate s aid fuse link engaging portions and said fuse link extracting portion.

26. A drop-out fuse construction comprising upper and lower stationary contacts, a fuse tube having a fuse link normally electrically joining said contacts, a lever pivoted on said lower contact and having a fuse link extracting portion adjacent said fuse tube and having a fuse link engaging portion spaced from said fuse link extracting portion, said lever normally occupying an elevated position and being movable downwardly to release said fuse tube for drop-out motion, an arm rigid with the lower portion of said fuse tube and pivoted to said lever, a spring pressed fuse link engaging lever having a fuse link engaging portion cooperating with said first mention fuse link engaging portion for gripping said fuse link, and a latch spring biased towards open position and normally positively latching said lever in elevated position, said latch having means engaging said fuse link intermediate said fuse link engaging portions and said fuse link extracting portion, said lower contact having a contact spring engaging said spring pressed fuse link engaging lever 27. A drop-out fuse construction comprising upper and lower contacts, a fuse tube having a fuse link electrically joining said upper and lower contacts, a lever pivotally supported from said lower. contact and normally occupying an upper position and movable to a lower position to release said fuse tube for drop-out motion, said lever having fuse link extracting portions on opposite sides thereof and having a hollow interior portion and having outwardly projecting said arm having laterally projecting fuse link engaging portions on opposite sides thereof cooperating with said hub like portions to grip said fuse link on either side of said lever, spring means urging said laterally projecting portions towards said hub like portions, a latch pivoted on said arm and having a latching portion locking said lever against downward motion, said latch being spring biased towards latch releasing motion, and a member operatively connected to said latch and controlling said latch and bearing against an intermediate portion of said fuse link.

28. A drop-out fuse construction comprising upper and lower stationary contacts, a fuse tube having a fuse link normally electrically joining said contacts, a lever pivotaliy supported from said lower contact and normally occupying an upper position and movable downwardly to release said fuse tube for drop-out motion, an arm rigid with the lower portion of said fuse tube and pivotally connected to said lever, said lever having projecting hubs on opposite sides thereof, spring pressed fuse link engaging levers on opposite sides of said arm and cooperating with said hubs to grip said fuse link, and a latch pivoted on said arm and having a latching portion positively locking said lever in its upper position, said latch being spring biased towards latch releasing motion and having lugs on opposite sides thereof for engaging an intermediate portion of said fuse link.

29. A drop-out fuse construction comprising upper and lower stationary contacts, a fuse tube having a fuse link normally electrically joining said contacts, a lever pivotaliy supported from said lower contact and normally occupying an upper position and movable downwardly to release said fuse tube for drop-out motion, an arm rigid with the lower portion of said fuse tube and pivotally connected to said lever, said lever having projecting hubs on opposite sides thereof, spring pressed fuse link engaging levers on opposite sides of said arm and cooperating with said hubs to grip said fuse link, said spring pressed fuse link engaging levers being joined by a manipulati g portion located rearwardly of said first mentioned lever, and a latch pivoted on said arm and having a latching portion positively locking said lever in its upper position, said latch being spring biased towards latch releasing motion and having lugs on opposite sides thereof for engaging an intermediate portion of said fuse link. p

30. A drop-out fuse construction comprising upper and lower stationary contacts, a fuse tube having a fuse link normally electrically joining said contacts, a lever pivotaliy supported from said lower contact and normally occupying an upper position and movable downwardly to release said fuse tube for drop-out motion, an arm rigid withrthe lower portion of said fuse tube and pivotally connected to said lever, said lever having projecting hubs on opposite sides thereof, spring pressed fuse link engaging levers on opposite sides of said arm and cooperating with said hubs to grip said fuse link, said spring pressed fuse link engaging levers being joined by a manipulating portion located rearwardly of said first mentioned lever, and a latch pivoted on said arm and having a latching portion P051- tively locking said lever in its upper position, said latch being spring biased towards latch releasing motion and having lugs on opposite sides thereof for engaging an intermediate portion of said fuse link, said lower contact having a contact spring engaging the manipulating portion of said spring pressed fuse link engaging levers.

31. A drop-out fuse construction comprising a support having upper and lower contacts, an expulsion type fuse including a fuse tube and a fuse link therein normally electrically connecting said upper and lower contacts, said fuse link projecting outwardly from said fuse tube, a main lever pivotaliy supported from the lower contact and pivotaliy supporting said fuse tube, said fuse tube dropping outwardly when said main lever rocks downwardly, and an auxiliary lever having a portion bearing against said fuse link and pivoted to said main lever and normally holding said main leveragainst motion, said auxiliary lever being released for rocking motion with reference to said main lever to thereby release said main lever upon rupture of said fuse link.

32. A drop-out fuse construction comprising a support having upper and lower contacts, an expulsion type fuse including a fuse tube and a fuse link normally electrically connecting said upper and lower contacts, said fuse link projecting outwardly from said fuse tube, a main lever pivotaliy supported from the lower' contact and pivotaliy supporting said fuse tube, the pivot support of said fuse tube from said main lever being substantially directly above the pivotal support of said main lever from said lower contact, said fuse tube dropping outwardly when said main lever rocks downwardly, and restraining means pivoted to said main lever and having a portion bearing against'said fuse link and normally restraining said main lever against motion, said restraining means being released upon rupture of said fuse link.

33. A drop-out fuse construction comprising a support having upper and lower contacts, an expulsion type fuse including a fuse tube and a fuse link normally electrically connecting said upper and lower contacts, said fuse link projecting outwardly from said fuse tube, a lever pivotaliy supported from the lower contact and pivotally supporting said fuse tube, said fuse tube dropping outwardly when said lever rocks downwardly, the pivot support of said fuse tube from said lever being substantially directly above the pivot support of the lever from said lower contact, said lever having a portion extending substantially transversely of the axis of said fuse tube, and a latch biased towards-open position and controlled by said fuse link positively interlocking with said lever to relieve said fuse link of stresses due to the weight of said fuse tube.

34. A drop-out fuse construction comprising supporting means having'upper and lower stationary contacts and having upper latch means and a lower pivot support means, an expulsion type fuse tube having an open bottom and having its upper portion normally held by said upper latch means, a fuse link within said fuse tube, a main lever for supporting said fuse tube, said main lever being pivotaliy supported from said pivot support means and being pivotaliy joined to said fuse tube at a point approximately directly above the point at which said main lever pivots on said pivot support, an auxiliary lever pivoted on said main lever and having a free end over which said fuse link is passed, and a contact spring carried by said lower stationary contact and bearing against said main lever and urging said fuse tube towards outward motion and stressing said fuse link, said fuse link being substantially free from stress due to the weight of said fuse tube and its associated parts.

35. A drop-out fuse construction comprising supporting means having upper and lower stationary contacts and having upper latch means and a lower pivot support means, an expulsion type fuse tube having an open bottom and having its upper portion normally held by said upper latch means, a fuse link within said fuse tube, a lever for supporting said fuse tube, said lever having means for extracting said fuse link when said fuse link is ruptured, said lever having two pivots one substantially directly above the other, said lever being pivoted on said pivot support and constituting one-pivot point, said lever being pivotally associated with said fuse tube and constituting the second pivot point, releasable latch means controlled by said fuse link for latching said lever to said fuse tube, and a spring car= ried by said supporting means and urging said fuse tube towards drop-out motion, said fuse link being tensioned by said spring and being substantianly free from strain due to the weight of the fuse tube and its associated parts.

36. A drop-out fuse construction comprising supporting means having upper and lower stationary contacts and having upper latch means, an expulsion type fuse tube having an open bottom and having its upper portion normally held by said latch means, a fuse link within said-tube extending out of the open bottom, a main lever pivoted at one point from said supporting means and pivoted at another point to said fuse tube, said points being substantially directly above each other, said lever having means for extracting said fuse link when said fuse link is ruptured, means controlled by said fuse link for normally restraining said main lever, and a spring urging the lower portion of said fuse tube outwardly.

37. A drop-out fuse construction comprising a support having upper and lower contacts, an expulsion type fuse tube, a fuse link located within said tube, said fuse link projecting outwardly from said fuse tube, a lever pivotally supported from the lower contact at one point and pivotally supporting said fuse tube at a secondpoint located above the first point, said fuse tube being adapted to drop outwardly when said lever rocks from normal position, said lever being normally restrained by said fuse link and having a projecting lug adapted to be engaged by the lower end of said fuse tube when said fuse tube has completed its outward dropping motion, and means carried by said lever for engaging said lower contact whereby the force due to arresting the outward motion of said fuse tube is transmitted directly transversely through said lever to said lower contact.

38. A drop-out fuse construction comprising a support having upper and lower contacts, an expulsion type fuse tube, a fuse link within said tube, said fuse link projecting outwardly from said fuse tube, a lever pivotally supported from the lower contact at one point and pivotally supporting said fuse tube at a second point located above the first point, said fuse tube being adapted to drop outwardly when said lever rocks from normal position, said lever being normally restrained by said fuse link and having a first means adapted to be engaged by the lower portion of the fuse tube when the fuse tube has completed its outward dropping motion, said lever having a second means substantially transversely directly opposite said first means relative to said lever, said fuse construction having a relatively stationary portion adapted to be engaged by the said second means of said lever, whereby the force due to arresting the fall of the tube is transmitted substantially directly across said lever from the said first means to the said second means.

39. A drop-out fuse construction comprising a support having upper and lower contacts, an expulsion type fuse tube, a fuse link within said tube, said fuse link projecting outwardly from said fuse tube, a lever pivotally supported from the lower contact at one point and pivotally supporting said fuse tube at a second point, said fuse tube being adapted to drop outwardly when said lever rocks from normal position, said lever being normally restrained by said fuse link and having a first means adapted to be engaged by the lower portion of the fuse tube when the fuse tube has completed its outward dropping motion, said lever having a second means substantially transversely directly opposite said first means relative to said lever, said fuse construction having a relatively stationary portion adapted to be engaged by the said second means of said lever, whereby the force due to arresting the fall -of the tube is transmitted substantially directly across said lever from the said first means to the said second means.

WILLIAM O. SCHULTZ. ALWIN G. STEINMAYER.

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