US2558957A - Fused drop-out cutout - Google Patents

Description

July 3, 1951 D. c. HUBBARD Erm.4 K' 2,558,957

F'USED DROPOUT CUTOUT Filed Aug. 8, 1949 4 Sheets-Sheet 1 lJ'uly 3, 1951 D. C. HUBBARD ETAL 2,558,957 FUSED DRoPoUT CUTYoUT Filed Aug. 8, 1949 4 sheets-sheet 2 75 2:67576 76 7? 79 72 40 /[V'T Y 'E' I l Q .l 46

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July 3, 1951 D. c. HUBBARD r-:rAL 2,558,957

FUSED DROPOUT CUTOUT 4 Sheets-Sheet T5 Filed Aug. 8, 1949 m N5 um July 3, 19.51 D. c. HUBBARD Erm. 2,558,957

FUSED DROPOUT CUTOUT Filed Aug. 8, 1949 4 .Sheets-Sheet 4` INVENTORS.

Patented July 3, 1951 FUsED onor-OUT cU'roU'r David C. Hubbard and William L. Hollander, Centralia, Mo., assignors to A. B. Chance Company, Centralia, Mo., a corporation of Missouri Application August 8, 1949, Serial No. 109,146

The present invention relates to fused dropout cut-outs, and is particularly concerned with drop-out cut-outs of the type which may utilize any standard universal fuse link now on the market, and which may be opened manually at the top as a disconnect, or opened automatically at the bottom responsive to the rupture of the fuse link.

One of the objects of the invention is the provision of an improved fused cut-out in which the lower contact of the fuse tube is ejected from the bottom contact arm of the support upon rupture of the fuse link, so that the fuse tube will hang with its opening down before and after operation, thus protecting the fiber liner of the fuse tube from all adverse weather conditions.

Another object is the provision of an improved cut-out structure which is especially adapted to delay the actual parting of the lower contacts, due to fuse link rupture, until after the arc has been extinguished within the fuse tube, so that the arc will always be extinguished before the physical parting of the contacts takes place.

Another object of the invention is the provision of an improved cut-out adapted to pull the fuse link from the fuse tube even when the rupturing currents are too light to generate sufdcient gases within the fiber liner to eject the link rapidly.

Another object of the invention is the provision of an improved cut-out which is trip free in that the automatic mechanism, which controls its opening responsive to the rupturing of aV fuse, may operate, even when the lineman is closing the upper contacts of the cut-out, in the event the fault still exists on the line. i

Another object is the provision of firm' stops to arrest the skyrocketing which is due to jet action, so that the contact springs will not be overstressed and so that the jet action will be employed to assure the retention of the upper trunnions by the upper contact arm as long as the blast exists.

Another object is the provision of an improved mechanism for the lower contact and ejector arm, by means of which the ejector arm is so rotated, responsive to the rupture of a fuse link, that the trunnion is moved out of its supporting groove, so that it can be ejected by the action of another spring carried by the contact supporting arm.

Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings, in which similar characters of reference indicate similar parts throughout the several views.

12 Claims. (Cl. 20o-114) Referring to the drawings, of which four sheets:

Fig. 1 is a side elevational view in partial section, showing a fused drop-out cut-out embodying the invention, with the two alternative open positions, shown in dotted lines;

Fig. 2 is a top plan view, taken on the plane pf the line 2-2 of Fig. 1;

Fig. 3 is a bottom plan view, taken on the plane of the line 3--3 of Fig. 1, looking in the direction of the arrows;

Fig. 4 is a front elevational view, taken on the plane of the line 4-4 of Fig. l, looking in the there are direction of the arrows;

Fig. 5 is a side elevational view of the upper contact arm and connector fixture;

Fig. 6 is a fragmentary sectional view, taken on the plane of the line 6--6 of Fig. 5, looking in the direction of the arrows;

Fig. 7 is a fragmentary sectional view, taken through the mechanism at the bottom of the fused cut-out assembly of Fig. 1, with the parts in the position which they assume when the fuse is ruptured, but before the contact has Abeen ejected from the contact supporting arm;

Fig. 8 is a fragmentary sectional view, taken on the plane of the line 8-8 of Fig. '7, looking in the direction of the arrows;

Fig. 9 is a sectional view, taken on the plane of the line Q-Slof Fig. '7, looking in the direction of the arrows;

Fig. 10 is a sectional view, taken on the plane of the line Ill-i0 of Fig. 9, looking in the direction of the arrows;

Fig. 11 is a fragmentary sectional View, taken on the plane of the line II-il of Fig. '7, looking in the direction of the arrows;

Fig. l2 is a fragmentary sectional view, taken on the plane of the line |2-I2 of Fig. 7, looking in the direction of the arrows:

Fig. 13 is a fragmentary sectional view of the upper contact supporting arm, taken on a plane passing through the axis of the arm, showing a modification;

Fig. 14 is a fragmentary sectional view, taken on the plane of the line H-M of Fig. 13, looking in the direction of the arrows;

Fig. 15 is a fragmentary sectional view, taken on the plane of the line I5-I5 of Fig. 13, looking in the direction of the arrows.

Referring to Fig. 1, 20 indicates a fused dropout cut-out assembly, which may be supported from a cross arm 2l by means of a pair of clamping brackets 22 clamped on the arm by tight bolts 23.

The clamping brackets 22 support an insulator 24 by means of a central clampingband 25; and the insulator 24 is provided with reduced cylindrical portions at each of its ends for receiving the clamping bands 26, 21, which carry the contact arms that support the fuse tube unit 26.

The upper contact arm may consist of a pair of the spring contacts 29, shown in Fig. 1, these contacts consisting of resilient wire bent into substantiall'y U shape, with two separate wires 38, 3 I, terminating at an easy bend 32.

One of the wires 29 preferably has a. full helical loop 33 for increasing its resiliency. The wires 38, 3| are bent toward each other at 34 and 35, being provided with transverse crossing portions 36, 31. The transverse portions 36 and 31 support the curved parts 38 and 39, each of which partially embraces the cylindrical trunnion 48 of the fuse tube unit.

Beyond the curved portions 38, 39 the wires close slightly upon the trunnion 'at the humps, indicated at 4| and thereafter the wires diverge at 42 and 43 to provide a bell mouthed opening for receiving the trunnions and guiding them into the position of Fig. l.

The contact wire 3| has a yoke at =44, which joins two legs of similar shape. The contact wire 38 is bent upwardly at 45 and has a yoke at 46 joining two Wires of similar shape. The curved ends 32 are made of this shape so that they can be caught in the groove of a, connector fixture 41, where they are clamped in grooves of similar shape.

The connector fixture 41 may consist of -a substantially rectangular body 48, having an upward extension 49 that serves as a connector. The integral extension I49 has a through bore 58 and a partially spherical socket I.

The upper surface of this extension 49 is formed with a pair of V grooves 52, one on each side of the hole 58, for receiving the tap wire 53 (Fig.5)

Referring to Fig. 12, this is a view showing the tap wire 53 clamped bythe connector bolt 54.

The connector bolt 54 has an annular head 55 with a through bore 56 for receiving the tap wire. The annular head carries an extension 51 on each of its opposite sides, for engaging the tap wire 63 above the V grooves 52. 'Ihe annular head 55 has a threaded shank 58, which passes through the hole 56; and on the opposite side of the connector extension 49 there is a spring washer 59 and a nut 68.

Referring again to'Fig. 5 and Fig. 6, the body 46 may be hollow, having a rectangular hole 6| extending through it, this hole being bounded by the sides 62, 63 and by the top 64 and bottom 65. The sides 62, 63 have registering apertures 66 for one screw bolt 61, and the other registering apertures 66 for the other screw bolt 69.

The sides are formed with an outwardly projecting ledge 18 below the wire 38 and a similar outwardly projecting ledge 1| above the wire 29.

At the left side of the body 48 (Fig. 5 and Fig. 6) there is a curved groove 12, which nts the curved end portions 32 of the two contact wires 29 and 39 when they are placed inside the anges 16 and 1| outside of the bolts which pass through the holes 66 and 68.

The clamping band 26 may consist of two separate half cylindrical parts, indicated at 13, 14. On the left side these partly cylindrical bands have a short attaching flange 15, which is joined by a through clamping bolt 16. On the right side of Fig. 2 these partly cylindrical bands 13, 14

have a longer attaching flange 11, in each case with holes that register with the holes 66 and 68, for receiving the screw bolts 16, 1l.

The attaching ilanges 11 are thus adapted to engage on the outside of the connector iixture 43, to clamp the wires 29 and 38 in the grooves 12; and the wires are also confined above and below by the flanges 18 and 1| (Fig. 5).

The upper contact springs 29 and 38 are provided with initial tension toward each other so that they tendI to close the tapered opening, which is formed by the portions 42, 43, but these portions are cammed apart by the upper trunnion 48 of the fuse unit 28, so that the curved portions grip the upper trunnion 48 and provide a connection with a low contact resistance.

The fuse tube unit 28 comprises a tubular insulating member 88, Vwhich is provided with an insulating liner 8|, and the insulating tube 88 supports an upper contact iixture -82 and a lowerv contact ilxture y83. The upper contact :fixture 82 comprises a substantially cylindrical metal member which is threaded to receive the cap =84 that clamps the upper button which is carried by the fuse cable.

The cylindrical body of the upper contact 82 has a pair of integral laterally projecting cylindrical trunnions 48 (Figure 2) and these trunnions are preferably arranged toward the outer side of the contact fixture 82, that is toward the right, so that the jet action from the lower end of the tube 88 tends to rotate the fuse tube unit 29 in a clockwise direction about the upper trunnions 48. This tends to keep the lower fixture 83 in engagement with its contact arm until the jet action has ceased, and prevents mechanical disengagement at the lower end until the arc is extinguished.

The upper contact .lixture--82 preferably has a downward extension 85 on its right side which carries an integral metal operating ring 86, by means of which the fuse tube unit is manipulated, using a fuse disconnect stick.

Both the fixtures 82 and 83 have cylindricalv bores for receiving the tube 88, and the tube may be secured in these fixtures in each case by transversely extending riveted pins 81, which are arranged at such a point that they merely groove the outside of the tube 88 and are insulated and spaced from the fuse cable.

The lower contact fixture 83 has a cylindrical body provided with the bore 88 for tube 88, and bore 88 communicates with a downwardly open blast chute 89. This blast chute comprises a pair of parallel side walls 98 and a curved rear wall 9|, which extends at its lower edge to the axis of the tube 88 and tends to direct the gases forwardly and downwardly toward the right, away from the operator.

The lower contact fixture 83 has a laterally projecting body 92 which is provided with a cylindrical bore 93 for housing a compression coil spring 94. In addition to housing the coil spring the extension 92 carries an integral manipulating ring 95 which may be engaged by a disconnect stick or the like.'

'I'he extension 92 also carries a pair of pivot ilanges 96 which are parallel to each other and provided with a through bore for receiving the pintle 91 of a fuse ejector lever 98. The fuse ejector lever 96 comprises an elongated metal member which may have a flat body 99, generally surrounded by laterally projecting border flanges |36.

'(6 The flat body 99 carries a cylindrical hinge formation atl its right side (Figure '1) for receiving the rivet 91. bymeans of which the ejector lever 98 is pivoted.' The end wall of the ilxture extension 92 is indicated at |02, and it is curved about the hinge formation I0| and has a flat stop surface I 03 at its end for definitely limiting the pivotal movement of the elector lever 98 by engaging the fiat side |04.

The ejector lever 98 has a V-shaped notch |08 formed on the side toward the compression spring 94, and a bifurcated metal strut |06 has its legs extending on both sides of the body 99 of the ejector lever in this notch |05.

The border wall |00, previously mentioned, engages the lower side of the strut |06 and keeps it from sliding out of the notch |05 in Figure 7. The other end oi' the strut |08 has an end portion |91 of reduced width which passes through an aperture in a metal disc |08 and extends into the spring 94. Thus the spring is enabled to bear upon the strut |06 by means of the disc |08, and spring 94 urges the ejector lever 98 in a clockwise direction about its pivot 91.

The ejector lever 98 also carries a tubular portion |09, the details of which are shown in Figure 9, and this tubular portion has a through bore |I0 for receiving a clamping button III. The clamping button III has a tubular part |I2 extending into the bore IIO, and has a circular head |I3 for clamping the cable leader ||4.

The tubular part ||2 has a threaded .bore I5 for receiving the threaded portion I I6 of a screw bolt having a wing head I I1. The annular lower surface ||8 of the wing head engages the end of the tubular portion |09. As the wing head I|1 is turned clockwise it is threaded into the button III, and draws the button head II3 inward, clamping the leader I |4.

The ejector lever 98 also has a tapered extension I I 9, Figure 7, which terminates in a grooved end |20, the two legs |2| of which are located on the two sides of the fuse leader |I4. Thus the fuse leader may be tensioned, as shown in Figure 1, by pivoting the ejector lever counterclockwise from the position of Figure 7 to that of Figure 1, compressing the spring 94; and thereafter passing the leader ||4 downward through the groove |20 in the ejector lever 98, and backward toward the left about the clamping button where the end of the lever is secured by turning the wing nut I I 1.

The ejector lever also carries a pair of integral laterally projecting trunnions |22, Figure 7, and these trunnions are adapted to provide a pivotal support for the fuse tube unit 28 on the lower contact fixture.

When the fuse tube unit is provided with a fuse as shown in Figure 1, the ejector lever 98 is held rigidly in fixed position with respect to the fuse tube unit 28. The trunnions |22 are located lowermost below the pivot 91 of the ejector lever, as shown in Figure 1.

The ejector lever has a tapered rearward extension |23, Figure 1, which is provided with a transverse pin |24. This pin engages the free end of a wire spring 25, which is used at a certain stage in the operation of the cut-out to eject the lower contact fixture 83 from engagement with its contact arm, which will now be described in detail.

The lower contact arm is carried by the clamping band 21. This clamping band may be constructed just like the upper clamping band 26, and its attaching flanges |26, |21, Figure 3, are apertured to receive the two screw bolts |28, |29.

These screw bolts |28, |29 support a lower contact arm iixture |30. The contact arm fixture |30 has its rear or left end hollow, having a rectangular through aperture I3| provided with a top wall |32, a bottom wall |33 and a pair of side walls |34, Figure '1. 'I'he side walls |34 are apertured to pass the screw bolts |28, |29, which pass through these side walls and through the clamping flanges |28, |21 to secure the contact arm fixture |30 to the clamping band 21.

The contact arm fixture |30 is formed with a hood for enclosing the mechanism, this hood being open at the bottom and the front side, The hood is formed by a rear wall |35, a pair of side walls |36 and a top wall |31. The same screw bolts |28 and |29, previously mentioned, are used to support the spring |25. Spring 25 has one end provided with a circular loop |38 extending about the screw bolt |28. It then has a diagonal portion |39 and a curved portion |40 which extends over the bolt |29 and terminates in a relatively straight free end portion |4|.

'I'he spring |25 may be U-shaped, having a transverse yoke |42 at its lowermost portion, in Figure '7, and there may be two legs which engage about the bolts |28, |29. Thus the yoke |42 may be located transversely of the border wall |00 of the ejector lever 98, so that the spring |25 engages the left side of the ejector lever and tends to force the entire fuse tube unit toward the right, away from the hooded fixture |30.

The fixture |30 also carries a connector similar to the one described in detail in Figure 5, this connector being carried by an integral flange |43 which carries a threaded bolt with an elongated head I44. The tap wire is indicated at |45.

-The side walls |36 of the hood, of fixture |30, are closer together at the bottom, as seen in Figure 3, having an offset at |46. Ihis oset portion is formed with an inwardly open groove |41 on the inside of each side wall for receiving the laterally projecting trunnions |22 on the ejector lever 98.

The inwardly open grooves |41 on the side Walls |36 extend backwardly and upwardly in Figure '1, being defined on the right side by the partition |48. On the rear side the groove is defined by a curved surface |49 so that the groove is rearwardly open to receive the trunnions At its lower end the groove |41 has a cylindrical portion |50, where the trunnions |22 come to rest. The curved wall |49 extends upward to a curved corner I5|, and is joined to a substantially straight top wall |52, which extends forwardly and downwardly out of the open side |53 of the hood.

The opening between the wall |52 and the partition |48 tapers backwardly and becomes wider forwardly, and the wall portions indicated at |54 are more widely spaced than the wall portions I36. Wall portions |54 are spaced widely enough to clear the ends of the trunnions |22.

The operation of this part of the cut-out is as follows:

Assuming the fuse tube unit 28 has been provided with a fuse and the ejector lever has been tensioned, and the cable lead secured by being clamped under the button the fuse tube unit may be lifted by a disconnect stick, the end of which passes through the ring 95.

The fuse tube unit 28 will then hang downward from the ring 95, being upside down, as shown in dotted lines at the bottom of Figurel. With the unit in this position the ring is out of the hood and the trunnions |22 arelocated uppermost, projecting laterally in both directions.

The contact fixture 85 may then be inserted into the contact arm iixture |30, or hood, and the trunnions |22 will pass below the wall |52 and above the partition |48 until the trunnions |22 reach the 4curved back wall |48, 'I'hen the fuse tube unit may be permitted to settle down and the trunnions |22 will pass into the groove |41' and come to rest upon the curved portion |80, winch serves as a bearing.

'Ihe :use tube unit is now in the position shown in dotted lines at the bottom of Figure 1. The operator may then remove the disconnect stick from the ring 85 and place it in the ring 88, and by manipulating the stick the operator may rotate the fuse tube unit 28 counterclockwise, in Figure 1, on itstrunnions |22, in the lowerbearing |50, until the upper trunnions 40 move into the tapered opening 48, 44 between the contact springs 28 and 88.

The counterclockwise motion is continued until the upper trunnions 40 spread the contact springs and move into the curved portions of these wires behind the hump 4|. Then the upper contact contact springs 28 and 8l so that these contact springs are not damaged.

' as to permit pivotal movement about the bolt |58.

Referring. to Figures 1a w 15, there show a modiiied iorm of upper contact arms for engaging the same iusetube unit. In this case'the upper clamping vband 28 has itsattaching flanges The iixture |58 has an integral upwardly extending ilange |68,l with a connector bolt |54, similar to those previously described for securing the tap wire |85. Fixture |58 extends forwardly toward the right from the box-like portion'-|58,

wires wm `retain the upper trunnions 4o, but it is possible to use the device as a manual disconnect by merely pulling on the ring 88 with a disconnect stick. Such a pull would move the i'use tube unit 28 clockwise to the position at the bottom left of Figure 1, indicating that it was purposefully opened as a disconnect.

I'he operational the fused cut-out, upon occurrence of a fault in the circuit which melts the fuse, isas follows:

When the fuse melts, the tension on the leader ||4, which is caused by the spring 84, and ejector lever 88, pulls the leader I4 out of the tube 80, and the ejector lever 88 is permitted to rotate from the position of Figure 1 to that of Figure 7.

During this rotation of the ejector lever, the trunnions |22 move in an orbit about the ejector lever 88, pivot 81, and the groove |41 is suitably curved to define this orbit. 'Ihus the trunnions |22 move upward out of the groove |41 until when the ejector 'lever comes to a stop the trunnions |22 are out of the groove |41 and in the open portion voi! the hood which opens out at |53.

In the meantime the spring |25 has been engaging the ejector lever, tending to move it toward the right, but the spring 84 is stronger and the spring 84 causes the ejector lever to rotate counterclockwise to the position of Figure 7, when the stop surface |03`engaged by side |04 limits further movement of the ejector lever.

The spring |25 then comes into play and it urges the ejector lever and the whole contact fixture 83 toward the right, in Figure '1, electing the contact fixture 83 from the hood |30, aiding the force oi.' gravity which tends to produce this same result.

The Jet action which is caused by the blast o! gases out of the lower end of the tube 80 tends to rotate the fuse tube unit 28 clockwise at its lower end about the upper trunnion 40. This jet action Itends to keep the lower contact xture 83 in the hood until the jet action has stopped.

I'he jet action is resisted by the ring 85 engaging the inside of the top wall |31, which is preferably provided with a downward curve at |55, tending to trap. the ring 85 under the hood until the jet action has ceased. This deilnite stop, provided by the top wall |31 engaging ring 85, prevents the jet action from over-tensioning the upper and has a downwardly open cylindrical socket |88 for receiving a compression spring |81.

In general, the fixture `|58 is. open on its lower side, being protected on its upper side by a top wall |88, which protects the mechanism, and by a pair of side walls |88 which protect and enclose both sides of the upper mechanism.

The side walls |88 are parallel to each other and are provided with apertures for receiving rivets or pins |10, which provide a pivotal support for a lower rigid jaw member |1I`. The jaw member |1| comprises a metal casting of substantially U-shape, having a pair of legs |12, |13, which are angular in cross section and which are provided -with an outwardly curved end portion |14 for guiding the fuse tube unit between the legs.

The yoke |15 may carry a triangular extension |18, with an upwardly extending integral pin |11 for engaging the spring |81. 'I'hus the spring |81 urges the lower jaw |1| counterclockwise, tending to clamp the upper trunnions 40.

The legs |12, |13 may have a partially cylindrical depression at |18, Figure 13, where they are intended to engage the trunnions 40; and the top of these legs |13, |14 may be provided with a downwardly curved end portion |18, to provide a tapered opening for guiding the trunnions' 40 into the space between the hood |58 and the loger law |1|.

a nood. The top wan lss and sidewalls lss devfine a. downwardly open box-like member whichv has an oiset |80, Figure l5, on each side, the oil set supporting downward wall extensions |'8|.

The offsets are not straight from front to back or left to right, but are formed with a partially cylindrical portion |82, Figure 13, which is open downwardly and toward the right in Figure 13. Thus the partially cylindrical portion |8| of the hood is opposed by the partially cylindrical portion |18 of the lower jaw I1 f These two partially cylindrical portions close about the trunnion 40, retaining `it between the jaws but permitting rotation. Thus the fuse tube unit can rotate about the upper trunnions 40 when the fuse blows or it can be used as a disconnect by using the upper ring |83.

This upper contact xture has the facility of adjusting itself to fuse tube units of diierentlength, as may be encountered due to the ordinary in accuracies resulting from mass production. If the fuse tube unit is longer, its trunnions 40 will engage the llower side |84 of offsets |80 and tend to pivot the casting |56 clockwise about the bolt |58, this being permitted by the elongated aperture IGZ.

' It the fuse tube unit is shorter than usual the upper contact iixture |56 may pivot in the opposite direction.

It will thus be observed that we have invented an improved fused drop-out cut-out which has the following advantages:

1. It is adapted to use standard universal fuse links of any manufacturer and to be handled according to conventional practice.

2 The lower contact of the fuse tube is ejected from the bottom contact arm upon rupture o! the fuse link so that the fuse tube will hang with its opening extending downward after operation, thus protecting the interior of the fuse tube from all adverse weather conditions.

3. The construction of the mechanism is such that the mechanical opening of the lower contacts is delayed until the arc has been denitely extinguished. i

4. The jet action from the lower end of the tube tends to keep the upper end of the fuse tube in its proper position and to hold the lower end in position untii after the blast, thus delaying mechanical opening until the arc has been extinguished.

5. The resilient spring contacts with their wide flaring ends are adapted to register with the trunnions ofA the fuse tube units, even though the dimensions may vary due to manufacturing tolerances and the contacts may give suillciently to become self-aligning as they engage the trunnions.

6. Any undue strain on the spring contacts is prevented by the provision of stop surfaces which take the thrust that is caused by jet action during rupture of a fuse.

'7. The present fuse unit may be operated as a disconnect switch, but when so operated its automatic mechanism is still trip-free, so that a fault on the line will open the lower contacts even while the operator is closing and holding the upper contacts.

8. The device givesa visual indication at all times whether it is actively in the circuit or whether the circuit has been broken purposefully at the top or automatically by rupture of a fuse at the bottom.

9. The present device is adapted to effect a self-alignment of the contacts and to accommodate manufacturing tolerances in the length of the fuse unit independent of the portions which grip the contacts. Shocks which might be imparted to the fragile fuse link element upon the closing of the fuse tube unit with its contact arms are substantially reduced and practically eliminated, as the slamming of thefuse tube into position forces the ejector arm against the bottom of the fuse tube and does not tend to place additional tension on the fuse link element.

While we have illustrated a preferred embodiment of our invention, many modifications may be made without departing from the spirit oi the invention, and we do not wish to be limited to the precise details of vconstruction set forth, but desire to avail ourselves of all changes within the scope of the appended'claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States. is:

1. In a fused drop-out cut-out, the combination of an insulating support with upper and lower 10 fuse tube unit comprising an insulating tube ope .at the bottom and closed at the top. said tube having upper and lower contact iixtures and supporting and enclosing a tensioned ruse engaging said nxtures, both said xtures being provided with a pair of oppositely directed aligned trun urging said ejector lever about its pivot to tension the fuse and to move the ejector lever tru'nnlons backwardly and upwardly in an orbit, said lower contact fixture being provided with a pair of spaced side walls for receiving the laterally projecting part of said lower contact fixture, and said walls being formed with inwardly extending guide surfaces engaging the top of the ejector lever trunnions to guide them backwardly and downwardly into backwardly and upwardly open bearing grooves carried by said walls, the pivotal movement of said ejector lever upon blowing the fuse moving the ejector trunnions backwardly and upwardly out of said grooves into an open space below said guide means to release the trunnions by gravity from the lower contact flxture.

2. In a fused drop-out cut-out, the combination of an insulating support with upper and lower spaced contact arms carried by said support. a fuse tube unit comprising an insulating tube open at the bottom and closed at the top, said tube having upper and lower contact fixtures and supporting and enclosing a tensioned fuse engaging said xtures, both said fixtures being provided with a pair of oppositely directed aligned trunnions, and the upper contact arm being provided with open jaws for receiving and supporting the upper trunnions for rotation, the lower contact xture comprising a laterally projecting part extending toward the lower contact arm and pivotally supporting an ejector lever, said ejector lever being attached at its end to the fuse and carrying the lower trunnions below the point of pivotal support of the ejector lever, spring means for urging said ejector lever about its pivot to tension the fuse and to move the ejector lever trunnions backwardly and upwardly in an orbit, said lower contact fixture being provided with a pair of spaced side walls for receiving the laterally pro- Jecting part of said lower contact xture, and said walls being formed with inwardly extending guide surfaces engaging the top of the ejector llever trunnions to guide them backwardly and downwardly into backwardly and upwardly open bearing grooves carried by said walls, the pivotal movement of said ejector lever upon blowing the fuse moving the ejector trunnions backwardly and upwardly out of said grooves into an open space below said guide means to release the trunnions by gravity fi'om the lower contact fixture, the said lower contact fixture being provided with second spring means engageable by the ejector lever spring means, the said second spring means serving after the ejector lever has moved to release its trunnions to assist the force of gravity in expelling the lower contact xture from the lower contact arm.

3. In a fused drop-out cut-out, the combination of an insulating support with upper and spaced contact arms carried by said support. a lower spaced Contact arms carried by Seid SUD- 'portafusetube nf unit comprising an insulating tube open at the bottom and closed at theton.

said tube having upper and lower contact fixtures and supporting and enclosing a tensioned fuse eneasing said flxtureaboth lsaid xtures beingprovided with a pair of oppositely directed aligned trunnions, andthe upper contact arm being provided with open jaws for receiving and supportsaid lower contact iixture being provided with a pair of spaced sidewalls for receiving the laterally projecting part of said lower contact xture, and said walls being formed with inwardly extending guide surfaces engaging the top of the ejector lever trunnions to guide them backwardly and downwardly into backwardly and upwardly open bearing grooves carried by said walls, the pivotal movement of said ejector lever upon blowing the fuse moving the ejector trunnions backwardly and upwardly out of said grooves into an open space below said guide means to release the trunnions by gravity from the lower contact fixture, the said walls being joined by an upper wall forming a hood, and the said hood engaging the top of said laterally projecting part of the lower contact iixture to resist the jet action of the fuse tube unit upon blowing of a fuse.

4. In a fused drop-out cut-out, the combination of an insulating support with upper and lower spaced contact arms carried by said support, a fuse tube unit comprising an insulating tube open at the bottom and closed at the top. said tube having upper and lower contact fixtures and supporting and enclosing a tensioned fuse engaging said fixtures, both said fixtures being provided with a pair of oppositely directed aligned trunnions. and the upper contact arm being provided with open jaws for receiving and supporting the upper trunnions for rotation, the lower contact xture comprising a laterally projecting part extending toward the lower contact arm and pivotally supporting an ejector lever, said ejector lever being attached at its end to the fuse and carrying the lower trunnions below the-point of pivotal support of the ejector lever,

spring means for. urging said ejector lever aboutl its pivot to tension the iuse and to move the ejector lever trunnions backwardly and upwardly in an orbit, said lower contact fixture being provided with a pair. of spaced side walls for receiving the laterally projecting part oi' said lower contact xture. and said walls being formed with inwardly extending guide surfaces engaging the top of the ejector lever trunnions to guide them backwardly and downwardly into backwardly and upwardly open bearing grooves carried by said walls, the pivotal movement. oi' said ejector lever upon blowing the fuse moving the ejector trunnions backwardly and upwardly out of said grooves into an open space below said,

guide means to release the trunnions by gravity from the lower contact iixture, the said walls being joined by an upper wall forming a hood, and the said hood engaging the top of said lateralLvprojecting part of the lower contact iixture to resist the jet action of the fuse tube unit upon mowing of a ruse, and said hood being;

downwardly curved at its forward end, tending to Vretain the lower contact fixture until the jet action of the fuse tube unit ceases and the cir- `cuit is broken, so that the lower contact fixture tion of an insulating support with upper and lower spaced contact arms carried by said support, a fuse tube unit comprising an insulating, tube open at the bottom and closed atthe top. said tube having upper and lower contact iixtures and supporting and enclosing a tensioned fuse engaging said fixtures, both said fixtures being provided with a pair of oppositely directed aligned trunnions, and the upper contact arm being provided with open jaws for receiving and supportting the upper trunnions for rotation, the lower contact ilxture comprising a laterally projecting part extending toward the lower contact arm and pivotally supporting an ejector lever, said ejector lever being attached at its end to the fuse and carrying the lower trunnions below the point of pivotal support of the ejector lever, spring means for urging said ejector lever about its pivot to tension the fuse and to move the ejector lever trunnions backwardly and upwardly in an orbit,

said lower contact fixture being provided with a pair of spaced side walls for receiving the laterally projecting part of said lower contact xture, and said walls being formed with inwardly extending guide surfaces engaging the top of the ejector lever trunnions to guide them backwardly and downwardly into backwardly and upwardly open bearing grooves carried by said walls, the pivotal movement of said ejector lever upon blowing the fuse moving the ejector trunnions backwardly and upwardly out of said grooves into an open space below said guide means to release the trunnions by gravity from the lower contact fixture, said upper jaws comprising a pair of U- shaped wires, one on each side of the fuse tube unit, the U-shaped wires crossing each other behind the upper trunnions, where they are formed with said jaws.

6. In a fused drop-out cut-out, the combination of an insulating support with upper and lower spaced contact arms carried by said support. a fuse tube unit comprising an insulating tube open at the bottom and closed at the top.

said tube having upper and lower contact fixtures and supporting and enclosing a tensioned fuse engaging said fixtures, both said fixtures being provided with a pair of oppositely directed aligned trunnions, and the upper contact arm being provided with open jaws for receiving and supporting the upper trunnions for rotation, the lower contact fixture comprising a laterally projecting part extending toward the lower contact arm and pivotally supporting an ejector lever, said ejector lever being attached at its end to the fuse and carrying the lower trunnions below the point of pivotal support of the ejector lever. spring means for urging said ejector lever about its pivot to tension the fuse and to' move the ejector lever trunnions backwardly and upwardly in an orbit, said lower contact fixture being provided with a pair of spaced side walls for receiving the laterally projecting part of said4 lower contact xture, and said walls being formed with inwardly extending guide surfaces engaging the top of the ejector lever trunnions to guide them backwardly and downwardly into backwardly and upwardly open bearing grooves carried by said walls, the pivotal movement of said ejector lever upon blowing the fuse moving the ejector trunnions backwardly and upwardly out of said grooves into an open space below said guide means to release the trunnions by gravity from the lower contact fixture, the said trunnions on the upper contact fixture being located on that side of the tube unit which is away from the insulating support, the jet action from the fuse tube tending to rotate the fuse tube clockwise about the upper trunnions and tending to retain the lower contact fixture in engagement with the lower` contact arm.

'7. In a fused drop-out cut-out, an upper contact structure comprising an insulating support, metal band means extending about the insulating support and having a pair of parallel flanges, a connector block located between said parallel flanges and having a pair of through bores registering with bores in the flanges, said connector block having each of its opposite faces formed with a forwardly open U-shaped groove facing each flange, a pair of substantially U-shaped wire contact members, each contact member having curved portions clamped between said flanges and spacer block, and said U-shaped wire contacts having forwardly extending portions formed adjacent their ends with partially circular trunnion bearings.

8. In a fused drop-out cut-out, an upper contact structure comprising an insulating support, metal band means extending about the insulating support and having a pair of parallel flanges, a connector block located between said parallel flanges and having a pair of through bores registering with bores in the flanges, said connector block having each of its opposite faces formed with a forwardly open U-shaped groove facing each flange, a pair of substantially U-shaped wire contact members, each contact member having curved portions clamped between said flanges and spacer block, and said U-shaped wire contacts having forwardly extending portions formed adjacent their ends with partially circular trunnion bearings, said contact wires crossing each other upwardly and downwardly backward of said trunnion bearing portions.

9. In a fused drop-out cut-out, a lower contact structure comprising an insulating support. a clamping band carried by said insulating support, a contact fixture secured to said clamping band by through bolts, said contact fixture having a downwardly extending rear wall, forwardly extending parallel side walls, and a forwardly extending top wall, the said side walls being provided with inwardly facing recesses, each recess being open at the front edge of said side walls and extending backwardly toward the back wall and curving downwardly and forwardly under a rearwardly extending partition carried by each wall.

10. In a fused drop-out cut-out, a lower contact structure comprising an insulating support,

. a clamping band carried by said insulating supvided with inwardly facing recesses, each recess being open at the front edge of said side walls and extending backwardly toward the back wall and curving downwardly and forwardly under a rearwardly extending partition carried by each wall, the said through bolts carrying a fuse tube, and an ejecting spring comprising a U-shaped spring member passing over one through bolt and under and about the other screw bolt.

11. In a fused drop-out cut-out, a lower contact structure comprising an insulating support. a clamping band carried by said insulating support, a contact xture secured to said clamping band by through bolts, said contact fixture having a downwardly extending rear wall, forwardly extending parallel side walls, and a forwardly extending top wall, the said side walls being provided with inwardly facing recesses, each recess being open at the front edge of said side walls and extending backwardly toward the back wall and curving downwardly and forwardly under a rearwardly extending partition carried by each wall, and a fuse tube unit provided with a lower contact fixture having a rearwardly extending part, said rearwardly extending part carrying a pair of aligned oppositely directed trunnions receivable between said side walls, the said trunnions passing backwardly and about the end of said partition into a lower part of said recesses.

12. In a fused drop-outvcut-out, a lower contact structure comprising an insulating support, a clamping band carried by said insulating support, a contact fixture secured to said clamping band by through bolts, said contact fixture having a downwardly extending rear wall, forwardly extending parallel side walls, and a forwardly extending top wall, the said side walls being provided with inwardly facing recesses, each recess being open at the front edge of said side walls and extending backwardly toward the back wall and curving downwardly and forwardly under a rearwardly extending partition 'carried by each wall, and a fuse tube unit provided with a lower contact fixture having a rearwardly extending part, said rearwardly extending part carrying a pair of aligned oppositely directed trunnions receivable between said side walls, the said trunnions passing backwardly and about the end of said partition into a lower part of said recesses, the said trunnions being carried by a pivoted ejector lever, spring pressed to move in such a direction as to withdraw the fuse and move the trunnions backwardly, upwardly, and forwardly out of said recesses.

DAVID C. HUBBARD. WILLIAM L. HOLLANDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name V Date 1,958,496 Rah May 15,1934 2,212,633 Bodendieck Aug. 27, 1940 2,290,382 Ramsey July 21, 1942 2,446,676 Yonkersl Aug. 10, 1948

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