US2301551A - Combined fuse cutout and disconnect switch - Google Patents

Description

Nov. 10, 1942. I w. D. KYLE 2,301,551

COMBINED FUSE CUTOUT AND DISCONNECT SWITCH Filed July 20, 1940 s Sheets-Sheet 1 I 13 Y fi 11 1o 1 Q29. 2 M4-J%.1INETOR.

ATTORNEY.

Nov. 10, 1942. I w. D. KYLE 2,301,551

COMBINED FUSE CUTOUT AND DISGONNECT SWITCH.

Filed July 20, .1940 3 Sheets-Sheet 2 INVENTOR.

ATTORNEY.

Nov. 19, 1942. w p KYLE 2,301,551

' COMBINED FUSE CUTOUT AND DISCONNECT SWITCH Filed July 20, 1940 's Sheets-Sheet 3 I 5.9 3 55 3e; E "I; 67 I I I I 63 8 16 at 7% INVEN OR.

' ATTORNEY.

Patented Nov. 10, 1942 COMBINED FUSE CUTOUT AND DISOONNEOT SWITCH William D. Kyle, Lake Forest, lll., assignor to Line Material Company, Milwaukee, Wis, a comration of Delaware Application Ill! 20, 1940, Serial No. 346,579

fimaima Both manual disconnect switches and automatic fuse cutouts are used extensively in power distribution systems and it is advantageous to the power companies to be able to use one and the same structure as either a disconnect switch or fuse cutout because, by the ability so to do, a reductlon of inventory can be effected and time and expense saved whenever it is necessary to substitute a fuse cutout in place of a switch. or vice versa.

It has previously been proposed to provide a disconnect switch having a removable blade which can be replaced by a fuse unit, thereby converting the switch into a fuse cutout; but it is preferable, at least in certain instances, to be able to eflect a desired conversion by simply installing a fuse link without having to remove a switch blade. That, accordingly. is the primary object of this invention.

A further object is to provide a convertible disconnect switch which is particularly suitable for use on high voltage lines and which is well adapted to cooperate with high voltage type fuselinks-more particularly fuse-links of the kind which are required normally to be subjected to mechanical tension by their supporting structure so as to effect quick extinction of the are when a blowout occurs.

Anotherobject of the invention is to devise a convertible switch which is economical both to manufacture and maintain and which is of real advantage and convenience to the power companies.

In the drawings which accompany this specification I have illustrated the preferred embodiments of my invention, but I wish it to be understood that I assert inventorship only of the broad subject matter defined by the appended claimsthe specific structures herein disclosed being generically-within the purview of my inventive concept, but specifically the invention of William 0. Schultz.

The specific disclosure of the present application is identical with that of the co-pending application of the aforementioned William 0. Schultt, namely, application Ser. No. 346,571 filed July 20, 1940, in which latter application the disclosed structures are claimed specifically.

Referring to the drawings:

m. 1 is a view in side elevation showing an embodiment of this invention operating as a fuse cutout.

Fig. 2 is a top plan view of the invention shown in Fig. 1.

Fig. 3 is an enlarged fragmentary view partly in section of the lower portion of the structure shown in Fig. 1.

Fig. 4 is a bottom plan view of the structure shown in Fig. 3.

Fig. 5 is an enlarged view taken on the line 5-5 of Fig. 7.

Fig. 6 is a view taken on the line 6-6 of Fig. 5.

Fig. 7 is a view in side elevation of the invention shown in Fig. 1 operating as a disconnect switch.

Fig. 8 is a top plan view of the structure shown in Fig. 7.

Fig. 9 is an enlarged view, partly in section, of the fuse link assembly shown in Fig. 1.

Like parts are designated by the same reference characters throughout the several views.

In Figs. 1 through 8 an elongated cylindrical insulator support I is provided with terminal members 2 and 3 mounted thereon by means of the bolts 4 which extend through the insulator l and are secured thereon by nuts 5 drawn tightly against the washers 5A.

Extending in parallel relation to the insulator I are conducting portions 8 and I which are integral portions of the terminals 2 and 3 respectively. Mounted on the portions 6 and I are connector elements 8 and l, commonly used, adapted to receive electrical conductors (not shown) for connection with the terminals. As

indicated, the support I is provided intermediate its ends with a hanger ll, shown fragmentarily, clamped to the support by means of the strap ll, bolts l2, and nuts ii.

In Fig. 1, the contact arm II is rigid and comprises a casting having at its outer end a contact head A including an upwardly curved wedgelike guide l5 provided, at the base of the guide and on each side thereof, with a pair of catches or switch arm-receiving slots l6 extending transversely of the guide and a pair of fuse link-receiving slots ll extending downwardly toward the arm ll. A second wedge-like guide I! extends downwardly and outwardly from the base of the guide I! and immediately in front of the slots It and terminates in a pair of switch arm spreading tips 2| clearly shown in Fig. 8. A reinforcing rib 2i, located centrally of the head A, extends laterally from either side of the guide I! upwardly along the guide it and downwardly along the wall portion 22.

The arm M comprises a base portion 213 and a rib 24 located centrally thereof, each extending from the wall portion 22 to the bolt receiving portion 25. As indicated in Fig. 2, the rib m4 terminates in a pair of divergent portions l6 and 21 flanking the triangular aperture 28 in the base portion 23. The opening 28 facilitates the mounting of the arm 14 on the terminal i! by pro--' viding an unobstructed passage for the "upper bolt 4 when inserted in the bolt-receiving portion conducting portions or legs 31A held in relatively fixed position relative to each other at the pivoted end of the arm 3| by a flat relatively stiif metal plate or spacing brace 32 having its ends bent at 33 into gripping engagement with the legs 31A.

The legs converge upwardly beyond the brace 32.

into a horizontal section 34 which terminates in a pair of fuss link-engaging portions 35 each of which is spaced from an adjacent leg to provide a fuse link receiving slot "A As indicated in Fig. 5, the portions II are formed by reversely curved portions of thewire comprising the legs HA.

The contact end 38 of the conductor which includes portions II, is provided with a tubular collar 31 having its flanged ends 38 engaging adjacent portions of the wire and holding the fuse link engaging portions in relative alignment to each other and to the arms 3IA when engaged by the fuse link hereafter described.

The conductor arm 3| is pivotally mounted on a terminal housing designated generally by the numeral 40 and comprising a rear wall ll, side walls II, a top wall 43 terminating in a curved portion 44 having a notch A, and an open bottom. The front of the housing is partly closed at its upper end by the curved portion 44, The rear wall H is provided centrally thereof with an aperture 45 receiving therein the bolt I which holds the housing in electrical and mechanical contact with the terminal 3. At the lower forward end of each side wall 42 a lug I8 is provided which is disposed immediately below an adjacent arm II A and acts as means for limiting the downward movement of the conductor 3|. As indicated, each arm IIA is provided with a hinge portion 41 extending into an aperture "A located in a corresponding side wall 42 and about the axis of which the conductor may freely swing.

A tubular spring bearing ll having a coil spring ll slldably mounted thereon is disposed in axial alignment with the apertures "A between the side walls 42 and held in placeby the hinge portions 41 which extend into the interior of the housing ll through the apertures "A as shown. A rectangular plate II is provided for holding the hinge portions 4'! in the apertures "A by flipping the legs llA at II. Anotcb is provided at I! on the plate il in relative alignment with the notch A and receives in contact therewith 7 he biasing arm I! of the spring II. The other end of ho spring ll is biased against the forward edge of the curved portion 44 by the arm 54.

It may be noted that the plates 32 and II hold each other. it may be further noted that due to the natural resilience of the legs SHA, some lateral movement or spreading takes place intermediate the plate the collar 31. This spreading action, which occurs when the conductor arm ill is engaged with the contact head MA, as more fully described hereinafter, is conby plate thereby provides a higher contact pressure between the cooperating parts of the conductor arms 3i and contact head MA than would be otherwise possible should the plate be It may be noted that the spring #59 disposed within the housing ill is protected against direct weathering such as snow, sleet and ram.

if it is desirable to utilize the structure as a fuse cutout, a fuse link assembly shown in Fig. 9 and designated generally by the numeral 55 is provided comprising a still metal tubular conductor BI having mounted adjacent its upper flanged end 52 a frusto-conical contact 53 and a flexible wire loop 55 and disposed within the tube M a strain wire 58 which is secured to the loop .56 by means of solder H which in turn secures the loop and contact 63 in fixed position with the tube il. A flexible conductor 55 is secured to the strain wire 58 by solder at 6B. A predetermined length of fusible wire 58 is electrically connected to the tubular conductor 8! at 50 and to the flexible conductor 65 at 66. A comparatively light. insulating tubular member 81 is tightly mounted on the conductor 6| so that its upper end comes into abutting relation with the contact 53 and its lower and extends a predetermined distance below the solder point 66. The tight fit between the tube 61 and conductor tube 5| forms a rigid arrangement of parts at the upper contact and of the assembly.

An anchor tube 88 having a flange i9 intermediate its ends is mounted on the conductor ll so that the flange abuts the lower end of the tube 61. The tube-6!, is anchored to the conductor 55 by pressing the walls of the tube ll below the flange 69 into locked position there with. The portion of the tube 68 above tho flange 6! acts to axially align the fusible wire II and strain wire il in spaced relation with the tube 81.

The lower end of the flexible conductor I is provided with a frusto-conical contact 1| having an aperture ll through which the conductor ll is passed to form a loop at 12. The loop and contact are secured together by any convenient means as solder (not shown). The loop is tinned to stiffen it as a ring.

The fuse link assembly II is mounted in the position shown in Fig; 1 by inserting the prong end of an insulated switch stick, not shown, in the upper loop 56. With the conductor arm I! in the open circuit position shown by the broken lines, the free end of the fuse assembly including the contact H is guided into either slot "A on the contact head 88. v

By moving the fuse link assembly upward against the restraining action of the spring II. the contact II is urged into a. positive electrical connection with the wire portions II. Further upward movement of the link places the upper contact I! in position for electrical insertion in either slot I! by guiding the tubular portion 6'! of the link into either slot II. It may be noted at this stage of the fusing operation that the energized portions of the device are insulated from the legs ilA against lateral movement relative each other by the tubular portion 81, thereby preventing arcing. By removing the prong endof the stick from the loop 88 the cone-contact 83 is snapped into positive circuit closing position with thevslot l1, and the assembly is securely held under proper tension between the contact heads Ma and 36 by the biasing action of the spring 49.

Two fuse link-receiving slots are provided adiacent the ends of each member l4 and 3| to permit fusing of the structure from either side, depending upon the convenience of either side to an operator and for the further purpose of changing to a higher or lower current rating fuse link without interrupting the service.

When the fuse link assembly 55 is ruptured by a fault current, the fusible wire 59 and the strain wire 58 are melted and the conductor arm ii is biased by the spring 49 into open-circuit position shown by the broken lines in Fig, 1, throwing the lower portion of the fuse assembly ineluding the flexible conductor 65, the anchor means 68 and a part of the ruptured fusible section free from the contact head 36. The upper end of the ruptured assembly is blown free from the contact head A by the gases generated by the melting of the fusible section, The structure is now in position to be re-fused in a manner heretofore described or it may be used as a switch as shown in Fig. 7.

When it is desired to use the construction as a manually operable switch, the arm I4 is positioned so that the wedge guide l5 points downwardly. This is done by loosening the upper bolt 4 and disengaging the nub 29 from the groove 30 and rotating the arm l4 to position the contact head as shown in Fig. 7.

The switch is closed by moving the conductor arm 3| by any convenient .means as a switch stick (not shown) upward toward the head A where the wedge-like guide I5 is received between the converged legs 3|A intermediate the plate 32 and the horizontal portion 34. The legs are spread due to their inherent resilience, as the member ii is moved toward the rear of the wedge l5. Further movement causes the legs IIA to snap into locked engagement with the slots l6.

It may be noted that the wedge [5 acts to wipe the contacting portion of the legs SIA free of any oxide coating or other current barriers. that might be associated therewith as the legs are moved along the wedge toward the slots i6. Accordingly, this wiping action by the wedge IS insures a clean and positive electrical contact between the slots I6 and the legs 3|A. It is further noted that the spacing of the slots It insures a high contact pressure between the legs IIA by holding the legs against their tendency to assume their narrower spacing.

The utility of the slot 44A may be noted by observing that the upward movement of the conductor arm 3| is facilitated by permitting the biasing arm 53 free movement into the slot, thereby permitting a substantially full upward swing of the conductor arm 3 I.

The switch is disconnected from the contact head A by reversing the previous movement of the conductor arm 3| by the same switch stick means. The legs 3|A are disengaged from their locked position with the slots l6 by the guide l9 which spreads the legs as the tips are received therebetween, and the conductor arm is moved downwardly against the guide l9. After the legs become released from the slots IS the spring 48 biases the contact into open-circuit position.

It may be noted at this time that the wedges l5 and I9 converge into a common base immediately adjacent the slots l8 and that the wedge i5 operates to engage the legs IIA with the slots, and that the wedge is operates to disengage the legs therefrom without the aid in either case of separate means being associated with the legs, thereby providing a relatively light-weight conductor arm 3| which may be quickly biased into open-circuit position, due to its substantially mass-free construction.

From the foregoing description, it may be seen that the objects of the invention have been attained by providing for an electrical distribution system a combined fuse cutout and disconnect switch having a resilient contact arm which may operate either as a switch arm or a fuse linkholding arm and a rigid contact arm which is provided with a contact head that may cooperate with the resilient conductor arm either as a fuse link-holding means or as a switch armreceiving means by simply reversing the position of the rigid arm. It is further noted that a combined switch and fuse cutout has been provided which is simple and economical to manufacture and efllcient and positive when operating either as a fuse cutout or as a switch.

I claim:

1. A switch including a terminal, a movable switch-blade operative, in closed position, to connect with said terminal and thus establish an uniused conductive path including said terminal and said switch-blade in series, means connected with said terminal for engaging one terminal of a fuse-link, said switch-blade having means for engaging the other end of said fuse-link, said first means and switch-blade being jointly operative to support said fuse-link when said switchblade is in open position, said switch-blade, terminal and fuse-link, in series, forming, conjointly, a fused conductive path.

2. A switch including a terminal, a movable switch-blade operative, in closed positiomto connect with said terminal and thus establish an unfused conductive path including said terminal and said switch-blade in series, spring means urging said switch-blade toward open position, means connected with said terminal for engaging one terminal of a fuse-link, said switch-blade having means, operative when said switch-blade is in open position, to engage the other end of said fuse-link, said first means and said switchblade being operative, conjointly, to support said fuse-link and apply tension thereto, said switchblade, terminal and fuse-link, in series, forming, coniointly, a fused conductive path.

3. A switch including a pair of terminals, a switch-blade for interconnecting said terminals, said switch-blade being connected with one of said terminals and operative, upon closure, to connect with the second of said terminals whereby to establish an unfused conductive path between said terminals, and means connected with said second terminal for engaging one terminal of a fuse-link, said switch-blade being operative, when in open position, to engage the other terminal of said fuse-link, said means and said switch-blade being operative, conjointly, to support said fuse-link with said fuse-link electrically interposed therebetween, whereby to establish a fused conductive path between said terminals.

4. A switch including a pair of terminals, a switch-blade for interconnecting said terminals, said switch-blade being connected with one of said terminals and operative, upon closure, to

connect with the second of said tei'irlinali" where by to establish an unfused conductive 1'; tween said terminals, means continued 5* til! said switch blade toward open position, an no connected with said second terminal for t one terminal 01' a fuse-link, said switch i being operative. when in open position, to l" the other terminal of said fuse link, said mentioned means and said switch-blade b operative, conjointly, to support said fuse and apply tension thereto, with said fuse-ii electrically interposed therebetween, whereby to establish a iused conductive path between terminals.

5. A switch including a pair of terminals, a

switch-blade for interconnecting said terminals, said switch-blade being connected with one of said terminals and operative, upon closure, to connect with the second of said terminals where by to establish an untused conductive path between said terminals, means continuously urging said switch-blade toward open position, manually releasable means for holding said switch-blade in closed position, and means connected with said second terminal for engaging one terminal of a. fuse-link, said switch blade being operative when in open position, to engage the other terminal of iuse link, said last mentioned means and said switeih--lalade being operative, conjointly, to support fuse-link; and apply tension thereto, with said allot"; electrically interposed there- "ween, W ereby to establish :tused conduce o. h between said term nals.

it, l switch including oi terzmnals, a switch-blade for interconnecting said switch-Made Boeing connected mt one oi said terminals and operative, upon closure, to connect with the second of said termini-tie leg? to establish an uniused conductive tween said terminals, a spring continue y urg- :lng said switch-blade toward open position, manually releasable means for holding switchhlade in closed position, and means connected with said second terminal for engaging one terminal of a fuse-iink, said switch-blade being operative, when in open position, to engage the other terminal of said fuse-link, said last mentioned means and said switch-blade being operative, conjointly, to support said fuse-link and apply tension thereto, with said fuse-link electrically interposed therebetween, whereby to establish a fused conductive path between said terminals.

WILLIAM D. KYLE.

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