US2493433A

US2493433A - Fused cutout

Info

Publication number: US2493433A
Application number: US619657A
Authority: US
Inventors: Edward H Yonkers
Original assignee: Joslyn Manufacturing and Supply Co
Current assignee: Joslyn Manufacturing and Supply Co
Priority date: 1945-10-01
Filing date: 1945-10-01
Publication date: 1950-01-03
Anticipated expiration: 1967-01-03

Description

Jan. 3, 1950 E; H. YONKERS FUSED CUTOUT 2 Sheets-Sheet 1 Filed 001;. 1, 1945 INVENTOR. Eduard/Y $721503, BY WW Patented Jane 3, 1950 U Nl T ED S TAT ES I FAT T 0 F FICE FUSED CUTOUT Application October .1, 1945, Serial No. 619,657

(Cl; 200-1 14=i 25 Claims.

The present invention relates to fused cutouts, and has for one of its objects the provision of an improved cutout of the dropout type which isof simple and rugged construction, is thoroughly reliable in operation, and which the fuse tube assembly may be easily and quickly mounted upon or detached from the spaced terminals of the insulator assembly. This application is a continuation in part of copending application Serial No. 567,021, filed December '7, 1944;

It is another object of the present invention to provide an improved and simple mechanism for quickly withdrawing the fuse link conductor from the fuse tube of the cutout when the fuse link is ruptured and for normally restraining the fuse tube assembly against dropout movement.

According to another object of the invention, the biasing means for the fuse extracting mechanism is arranged to perform the additional function of guiding both ends of the fuse tube assembly into engagement with the terminals of the insulating support as the fuse tube assembly is mounted upon the insulating support.

In accordance with still another object of the invention, the means for biasing the fuse extracting mechanism is detached from the fuse tube assembly and serves normally to restrain the fuse tube assembl against dropout movement and also to produce pressure engagement between the current conducting and engaged i hinge parts of the two assemblies so long as the fuse extracting mechanism is not operated.

It is a further object of the invention to provide a cutout of the character described wherein the fuse tube assembly is comprised of rigidly related parts and dropout movement of the assembly is effected by lateral movement of the pivoted end of the assembly incident to fuse rupture.

It is still another object of the invention to provide for use in a fused cutout, an improved fuse pigtail extracting arm which embodies exceedingly simple facilities for securely connecting a fuse pigtail conductor thereto.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawings, in which:

Fig. l is a side view, partially in section, illustrating an improved cutout characterized by the features of the present invention;

Fig. 2 is a sectional view taken along'the lines 2--2 of Fig. 1;

Fig. 3 is a fragmentary front view furtherillus;

2. tra'ting'the" lower terminal assembly of theinsula-ting support embodied in the device;-

l'is'a fragmentary bottom view of the fuse tubeflassembly illustrating the construction of thefuse extracting arm embodied therein;

Fig. 5'is'aside view of the supporting and extracting arms forming a part of the fuse tube assembly;

Fig. Gisa curve illustrating one of the operating characteristics of the device;

Fig. '7 isa fragmentary side view illustrating amodified form of the invention;-

Fig. '8 isa sectional view taken along the lines 8-9ofFig. 1; and

Fig. 9 is a sectional view taken along the lines '9-90'f Fig; 7;

Referring now'to the drawings, and more particularly-to Figs. 1 through 5 thereof, the present improved fusedcutout is there illustrated as comprising the usual insulating support in the form of a petticoat insulator it having a center Zone longitudinall thereof clampingl-y embracedby a bracket H which maybe utilized in supporting thecutout upon a pole or another suitable supporting structure. At its respective upper and lower-ends the insulating support Ill is provided with spaced apart upper and lower terminals indicated generally at [2 and i8, respectively, and between which a fuse tube assembly 24 of the expulsion type is adapted to be supported.

Specificallmthe upper terminal I2 comprises a conductive channel memberof -U-shaped cross section throughout its length having an integrally formedhalf collar I211 at one end thereof forembracing the collar seat provided at the upper end of the insulating support It. This portion of the terminal i2 is clamped against the seating surface of the support l0 by means of a half collar clamping member f3 and clamping screws Eta disposed upon opposite sides of the-support HI. At the late'rally extended end thereof, the upper terminal member is provided with downwardly extending hood skirts I20 and i211, the upper portions of which are arranged in meeting engagement with an overhang-inglip lZe extending downwardly from the top member l2. Thus, the parts life, 12d and We define a hooded or par-v tially enclosed space .at the extended end of the terminal member I2 for receiving therewithin the upper end of the fuse tube assembly-24. To prevent this end of the fuse tube assembly from being movedbeyonda predetermined point longitudinally of the'skirts lzcand 12d as the assembly is swung into its closed circuit position, a stop pinziZb .is provided :which extends transversely between the two identified skirts. This pin is arranged to coact with a retaining element in the form of a double leaf spring catch member M to restrain the fuse tube assembly 24 against pivotal dropout movement to the open circuit position thereof. At one end, the two leaves of the spring l4 are anchored to the under side of the upper terminal member by means of a terminal screw I5 which is threaded through a reinforced top side portion of the terminal member. Upward travel of the retaining element l4 during dropout movement of the assembl 24 is limited by an adjustable stop screw Mb threaded through the top wall of the member [2 to engage the element I4 intermediate its ends. A clamping washer IT and nut I6 threaded onto the screw l5, may be utilized to establish line wire connections with the upper terminal member.

The detachable fuse tube assembly 24 comprises the usual expulsion fuse tube 25 formed of an inner layer of pressed fibre or the like, having good are extinguishing gas evolving properties, and an outer layer of Bakelite impregnated paper having excellent insulating properties. At its upper end, this fuse tube is provided with a terminal ferrule 28 having a threaded end portion for receiving the internally threaded terminal cap 29. This cap acts as a tube end part engageable with the retaining element M to restrain the fuse tube assembly against dropout movement. To insure seating of the cap in a fixed position and thus prevent variations in the distance between the upper end of the cap and the point of pivotal support of the fuse tube assembly, the ferrule 28 is provided with an inwardly directed shoulder 28a against which the lower rim 29a of the cap may be tightly screwed. The two

terminal parts

28 and 29 are arranged to have the head 30a of a fuse link 30 clampingly held therebetween internally of the fuse tube 25. Specifically, the head 38a of the link is clamped against the upper end of the ferrule by means of coil spring 291) which extends downwardly from and is permanently attached to the top wall of the cap 29 internally of the cap. This fuse link, which preferably is of the improved form disclosed and claimed in applicants copending application, Serial No. 533,824, filed May 3, 1944, now Patent No. 2,453,688 granted Nov. 9, 1948, is provided with a pigtail conductor 3| extending ngitudinally of the tube 25 and out of the open lower end of this tube.

The tube 25 is arranged to be supported by a laterally extending and conductive supporting arm 26 which is of inverted T-shaped cross section throughout the major portion of its length. This supporting arm is provided with a ferrule 26c through which the lower open end 25a of the fuse tube 25 is driven to provide a pressed fit connection therebetween. Interengageable hinge parts respectively mounted upon the lower terminal l8 of the insulating support In and the extended end of the supporting arm 26 are provided for pivotally supporting the fuse tube assembly 24 upon the insulating support it). Specifically, the lower insulator terminal I8 is comprised of two half-cup parts I81; and [8b which are screw clamped to embrace the lowermost petticoat of the insulator ID. The terminal part l8b is provided with hinge means in the form of two transversely spaced apart, hook shaped brackets l9 and 2| having elongated and aligned trunnion receiving seats Ho and Zla formed therein which extend substantially normal to the longitudinal axis of the fuse tube '25. These brackets also respectively include guide noses I91) and 2!?) which are utilized in the manner explained below to guide the hinge trunnions of the fuse tube assembly 24 into engagement with the seats i966 and 21a. The other part 58a of the lower terminal 18 is provided with a downwardly extending portion having spaced apart parallel sides within which is supported the curved portion 200 of a U-shaped and twin leaf tensioning spring 2E3. This portion of the terminal part l8a is also used to mount the clamping parts of a line terminal assembly 22 in an obvious manner. The U-shaped tensioning spring 2|] is held assembled with the terminal part lBa by means of an assembly pin i812 fixedly anchored to the bottom wall of the terminal part l8b.

As indicated above, the hinge parts of the fuse tube assembly 26 comprise a pair of trunnions 25c and 26d located at the extended end of the supporting arm 26 and extending transversely outward therefrom. More specifically, the supporting arm 2G is provided at its extended end with a forked portion comprising transversely spaced end parts 26a and 262) having the trunnions 25c and 26d formed integral therewith at their respective ends. The two identified trunnions are adapted for pivotal and sliding engagement with the elongated trunnion seats I911 and 2m, respectively, of the two brackets l9 and 2|. They are fiatted along the upper sides thereof, as indicated at 26c for the trunnion 260, in order to prevent removal from the trunnion seats or placement thereon except when the fuse tube assembly occupies its lowered or released position.

For the purpose of rapidly withdrawing the fuse link conductor or pigtail 3| from the fuse tube 25 upon rupture of the fusible element of the link, there is provided a one-piece fuse extracting arm 33 which is die formed from fiat resilient strip metal stock, such for example, as Phosphor bronze, is pivotally supported upon the arm 26 and is substantially coextensive in length therewith. The main part of this arm is bent into the configuration shown in Figs. 4 and 5 of the drawings to have parallel extending intermediate and return bent portions 330, and 36, a loop-shaped end bridge 35, and an end pivot piece 330 which is bent around a pivot pin 33d seated within aligned bearing openings bored centrally of the

trunnions

26c and 26d. Thus the extracting arm 33 has the same axis of rotation as the fuse tube assembly 24. Intermediate the ends of the arm 33, means comprising a headed tie post 32 are provided for securely connecting a fuse link pigtail conductor 3! to the arm. Specifically, the post 32 is fixedly mounted upon the intermediate portion 33a of the arm and extends downwardly through a slot opening Sta in the return bent portion 36 of the arm. The dimensions of this slot opening are slightly greater than the cross sectional dimensions of the post 32, thus permitting unrestricted movement of the arm portion 36 toward and away from the arm portion 33a. At its extended end, the post 32 fixedly supports a flat pigtail retaining head 32a having its ends 321) bent slightly over the side edges of the arm portion 36. The tie post 32 and head 32a serve normally to stress the arm portion 36 toward the arm portion 33a, so that when a fuse pigtail conductor 3| is wrapped around the post 32 it is clamped against the underside of the head 32a by the arm portion 36.

In order to tension the fuse link conductor 3! through the arm 33, camming means are formed integral with this arm to coact with the spring enemas 2-0 in producing a. downwardly directed pull upon the: conductor" 3! as the fuse tube assembly is retated into its closed circuit position. Specifical- 1y, this camming means comprises a substantial- 1y fiat segment 33b and a curved segment 336 interposed between the" pivot pin 33d and the straight intermediate portion 33a of the arm 33, These camming segments are normally disposed between the spaced apart end parts 23v; and: 26b of the: supporting arm 26 to be engaged by the lip and b of the spring leg 212d which extends be tween the two hinge brackets is and 2 I. As explained more fully below, the shape of the cammine segments 33b and 3-30 of the arm 32 is of considerable importance in obtaining the desired pull upon the fuse link conductor 3!, preventing this conductor from being t'ensioned in excess of a predetermined pull, and insuring pigtail conductor extraction in the event the extracting arm 33 is partially pivoted away from the supporting arm 26- as' a result of stretching of the pigtail conductor and fuse link during prolonged service of the cutout With-out refusing.

In order to provide for switch stick manipulation of the

hinge trunnions

26c and 26d into engagement with the trunnion seats of the

brackets

19 and 2 1, respectively, the upstanding center part of the T-shaped supporting arm 28 is enlarged at a point adjacent the forked end of the arm to provide for the formation of an opening therein into which the hook of a switch stick may be inserted. This opening is comprised of a first part 210. of enlarged diameter through which the switch stick hook may be inserted, and an offset part 2117 of smaller diameter into which the shank portion of the hook may be projected to prevent disengagement of the hook and the fuse tube assembly.

To facilitate swinging of the fuse tube assembly into and out of its closed circuit position, the upper terminal member or ferrule 28 of this assembly is similarly provided with an enlarged and integr'ally formed loop 28b into which the hook of a switch stick may be readily inserted.

From the above explanation it will be apparent that when the fuse tube assembly 24 is detached from the terminals of the insulating support Hi, the sup-porting arm 26 and the extracting arm 32 are freely rotatable relative to each other. When it is desired to fuse the assembly 24, the terminal can 29 is unscrewed from the ferrule 28 and a fuse link 30 inserted within the chamber of the tube 25 so that the pigtail conductor 3! thereof projects' out of the open lower end 25a of the tube, Following this operation, and with the extracting arm 33 firmly engaged against the supporting arm 26, the projecting end of the conductor 3| is carried over the bridge portion of this arm, tensioned and wrapped around the tie post 32 between the arm portion 36 and the head 32a. One or more turns may be taken around the post 32 as desired. As the turns are taken around the post 32 the arm part 35 is moved toward the arm part 33a, thus deforming the

connected parts

33d, 35 and 35 so that the turns are tightly squeezed between the arm part 36 and the head 32a, thereby frictionally to hold the conductor turns against slippage. Thus, the pigtail conductor serves tightly to hold the arm 33 in engagement with the underside of the supporting arm 26. After the described operations are completed, the terminal cap 29 may be threaded. onto the ferrule 28 until the cap-rim 29a abuts the shoulder 2861, thereby to establish the exact desired distance be--..- tween the top of thercap and the axis of the trunnions 2 B.c-and 2501. As the cap 29 .is screwed onto the ferrule: 23,- the spring 29b is compressed to clamp' thehead 30d of the fuse link tightly against the upperend of the ferrule; I

In order to mount the fuse tube assembly 2t upon the? terminals of the insulating support 1'0, the hook ofaswitch stick is first inserted through the opening2larto bring the shank portion of the hookinto registry with the opening part 21b of re-; duced diameten Interlocking of the hook shankwiththe sides of 'the'smalldiameter opening. 2Tb serves to preventinadvertent removal of the as'- sembly 24? from the end of the. switch stick In this regard it is: noted that the switch hook opening is positioned along the supporting. arm 28 adjacent the extended end thereof so that as the. switch hook is:elevated to raise the assembly 24', the center of gravity of the assembly is well below the hook, thus providing for maintenance of the interlocked connection between-the hook and the a small diameter opening Zib, and for easy manipu-- lation-of-the trunnions 25c and 26d into engagement with thebrackets, l9 and 2| of the lower terminal i8. As these trunnions are manipulated to bring the same into engagement with the identified brackets, they are first engaged with the guide noses lb and 2 [b.of the brackets. Concurrently with such en agement, the upturned lip 20b of the biasing spring; 20 engages the camming. surface 33b of the extracting arm 33. Thus, as the assembly 24 is-man-ipulated to push the ex tended end of the arm 26 toward the brackets l9 and 2], the spring 20, through its engagement with-the extracting arm 33, functions to guide the

trunnions

26c and 26d into seating engagement with the seats l9a and Z-Ia.

After the assembly 241s thus pivotally mounted upon lower terminal [8 of the insulating support It), the hook of the switch stick may be withdrawn from the

openings

21a and 21b and insertedinto the opening of the loop 2% for the purpose of rotating the assembly 24 about the

trunnions

26c and 26d into its closed circuit position. As the fuse tube assembly 24 is rotated in a counter clockwise direction to its closed circuit position, the arm 20d of the biasing spring 20 rides up the camming surfaces 33b and 33e of the extracting arm 32. Thus, the spring 20 is caused toreact between the support Ill and. the extracting, arm 32 to perform three additional functions. First, it forces the trunnions 26c and 25d forwardalong the seats I and 2la toward the noses I9b and 21b of the brackets I9 andZl, thereby to position the fuse tube end part 29 for interlocking engagement with the retaining element l4. Secondly, it biases the bridge end 35 of the extracting arm 32 away from thesupporting arm 26 to tension" the pigtail conductor 3| andhence the fusible element within the fuse link 38. Thirdly, it functions tofor-ce the

trunnions

26c and 26d into pressure engagement with the forward ends of the bracket seats 19a and Zia. Such pressure engagement between the two identified trunnions and their engaging brackets serves accurately to center the upper end of the fuse tube assembly 24 relative to the front or entrance opening be tween the skirts I20 and 12d of the upper terminal I 2. 'Thus, the upper endof the assembly 24 is, through'the action of the spring 28, forced intoa setting such that regardless of the direc tion from" which'the upward pivoting force isimposed upon the assembly, it will move betweenthe skirtslZc and |2d during the final pivotal movement: of the assembly into its closed cir cuit position. As the tube end part 29 moves between the skirts I20 and 12d, it engages the catch portion Md of the retaining element 14 and rides beneath this portion of the element until it is brought to bear against the stop part 12b. During final movement of the tube end part 29 toward the stop part I2b, the tube end part 29 rides beneath the lip Ma and seats against the under side of the element M to deform this element upward about the end of the stop screw Mb. With the spring element thus deformed, it exerts a thrust longitudinally of the tube 25 having a component which tends to move the

trunnions

26c and 26d to the left. Such movement is prevented by engagement of the arm camming portion 33a with the' spring part 20b. The upper end of the fuse tube assembly is prevented from rotating away from the closed circuit position thereof through its engagement with the lip Ma of the element l4.

Thus, the fuse tube assembly 24 is fixedlymounted upon the insulating support It to provide a fused current path between the two terminals I2 and i8. Specifically, this path extends from the terminal screw I through the conductive arm I2 and the spring H to the terminal cap 29. From this point, the conductive path extends through the fusible element of the link 30 by way of the flexible pigtail conductor 3|, the extracting arm 33, the spring 20 and brackets I9 and 2|, and the conductive terminal parts l8a and l8b to the line terminal assembly 22. It will be noted that the spring I4 thrusting down on the fuse tube and the spring 20 thrusting.

against the camming portion of the arm 33 serve to hold all contacting parts of the fuse tube assembly and insulator terminals in pressure engagement, thereby to minimize contact resistance therebetween. 1

So long as current flow over the described conductive path between the terminals l2 and I8 does not exceed the current-time fusing char,- acteristic of the link 30, the fusible element within the link 3|] serves mechanically to hold the extracting arm 33 in its set position against the underside of the supporting arm 26. When, however, this fusible element is required to carry current in excess of a predetermined magnitude for more than a predetermined interval, it is ruptured to relieve the holding force imposed upon the extracting arm 33 through the pigtail 3|. The spring 20, in reacting between the support ID and the camming surfaces of the arm 33 is thus rendered operative rapidly to rotate the arm 33 downwardly about the pivot pin 33d, thereby to withdraw the pigtail conductor 34 from the lower end of the fuse tube 25. In this regard it is noted that the arm 33 is of substantial length, such that rotation thereof through a relatively small angle produces a relatively large displacement between the bridge end 35 thereof and the lower end of the tube 25. Further, this arm is of small mass and hence has little inertia, thus insuring rapid acceleration of the bridge end 35 thereof away from the lower end of the fuse tube 25. In fact, the arm 33 and the spring 20 are preferably so designed that the arc is sufiiciently elongated during the first voltage half cycle following fuse rupture to prevent breakdown of the gap during the next sue ceeding voltage half cycle. Further, the length of the extracting arm 33 and the angle of move ment of the bridge end 35 thereof is such that, under any and all conditions of fuse rupture, all

of the pigtail conductor 3| and the lower unfused segment of the fuse link are completely removed at high speed from the bore of the fuse tube 25 to hang downwardly in alignment with the long axis of the insulating support [0. This arrangement is to be distinguished from conventional dropout cutouts wherein only partial pigtail conductor extraction is produced incident to fuse rupture.

As the arm 33 is rotated to a position approximately normal to the supporting arm 26, the camming surface 33b thereof tends to move away from the spring part 20b, thus relieving the force holding the

trunnions

26c and 26d at the forward ends of the

horizontal trunnion seats

19a and 21a. As this force is relieved, the spring retaining element M in thrusting downward upon the tube end part 29, slides the trunnions away from the bracket noses I9b and 2lb, i. e. to the left along the

trunnion seats

19a and 21a. After the static friction between the trunnions and trunnion seats is broken and with the extracting arm camming portion disengaged from the spring part 23b, gravity forces acting upon the fuse tube assembly are sufficient to continue the movement of the trunnions until they reach the rear ends of the trunnion seats. As such movement of the trunnions occurs, the distance between the trunnions and the retaining element catch portion Ma is obviously increased and the lower end of the fuse tube is moved toward the support It in a direction substantially transverse to the long axis of the fuse tube. Such movement of the fuse tube assembly as accom panied by angular movement of the tube end part 29 to tilt its right upper edge downward and by movement of this part away from the retaining element [4, until a point is reached where the catch Ma no longer engages the side of the tube end part 29. Thus the fuse tube assembly 24 is released for downward pivotal dropout motion about the axis of the

trunnions

26c and 26d under the influence of gravity forces acting thereon.

From the above explanation it will be apparent that dropout movement of the fuse tube assembly 24 is effected, without collapsing the assembly, primarily by moving the lower pivot support transversely of the longitudinal axis of the fuse tubes to increase the distance between the point of pivotal support and the upper end retaining element [4. The importance of exactly positioning the cap 2s relative to the other parts of the assembly, i. e. in a position such that its rim 29a tightly seats against the shoulder 28a, thus becomes apparent. In this regard it is noted that the length of the

trunnion seats

19a, and 21a is so related to the permissible downward travel of the retaining element l4 that release of the tube end part 29 from the retaining element is assured during the described transverse sliding movement of the trunnions along the trunnion seats. Specifically, the trunnion seats l9a and 2 la are of fixed uniform length. The downward travel of the retaining element I4 may, by suitable adjustment of the screw 14h through the terminal part [2, be limited as required to insure full release of the tube end part 29 from the element M as the trunnions move toward the rear ends of the trunnion seats.

From the above explanation it will be understood that release of the fuse tube assembly for dropout movement is accomplished upon fuse rupture by sliding the lower end of the assembly to the left in a horizontal plane in order to effect downward movement accompanied by angular tilting movement of the cap 23. The same result may be accomplished, if desired, by increasing the lengths of the trunnion seats and tilting the seats upward at the rear ends thereof so that the cap as is not lowered but is only tilted to move its upper rightedgedownward as the trunnions are slid upward along the trunnion seats under the influence of the element Min response to rupture of the fuse link.

Two of the problems involved in the-construction-of any cutout embodying a fuse extracting mechanism are those of preventing the fusible element of the link from being overtensioned to change the operating characteristics of the link, and of obtaining fuse remnant extraction upon fuse rupture even though the extracting arm has 'moved partially away from its fuse tensioning position as a result of stretching of the fusible element and pigtail conductor of the link. The critical tension beyond which the fusible element of the link should not be tensioned varies for links 'of different sizes or current ratings. In general, however, it is safe to employ a pull not exceeding 12 pounds upon the pigtail conductor of a'lin'kof the smallest rating. In the illustrated embodiment of the invention, the camming parts 337) and 33a are so shaped that the pull exerted upon the pigtail conductor 3! is limited not to exceed a predetermined value. Thus it will be noted that the camming part 33b is of sharply increasing radius away from the axis of rotation v.o'f the assembly 2:; and hence is effective rapidly to deform the leg Mid of the spring Zii during initial movement of the fuse tube assembly 24 toward its closed circuit position. During move- "ment of the .camm-ing lip 2% over these camming parts of the arm 32, the tension imposed upon the fusible element of the link 30 through the conductor 3| isincreased in accordance with the characteristic curve A illustrated in Fig. 6 of the drawings. Specifically, as the spring arm 'iild is moved from a position in engagement-with the point a along the camming 'part' 33b to a position in engagement with the "point b 'therealong, the tension imposed upon the fusible element of the link is rapidly increased from a zero value to a value at which may be approximately 3 or l pounds. During continued rotation of the assembly 24 toward its closed circuit position, the spring arm 25d rides upon the part 336 of the arm 32. This camming part is of only slightly increasing radius relative to the axis of pivotal rotation of the assembly. Accordingly, for a large angle of movement of the assembly 24;, there occurs only a small increase in the deformation of the spring As .a result, and again referring to Fig. 6 of the drawings, the tension imposed upon the fusible element of the link is only increased the small increment de during movement of the arm 2% from the point b to the point in engagement with the arm part 33c. Thus, it will be noted that after the fuse tube assembly is rotated through a predetermined angle, further rotation of the assembly towards its closed circuit position produces only a small increase in the tension imposed upon the fusible element of the link.

In accordance with a further feature of the invention, the fuse link tensioning facilities are so arranged that force is imposed upon the extracting arm 33 throughout the major portion but not the entire range of angular movement thereof. Thus the configuration of the camming parts 331) and 336 is such that during rotation of the-arm 33 toextract the conductor 3| from the fuse tube, the lip 20b of the spring 20 is biased against these parts until the arm 33 is rotated through an angle of approximately degrees or to a positionsubstantially normal to the supporting arm 26. Further, and again due to the small change in radius of the part 33c between the points i) and c 'therealong, the biasing force acting upon the arm '32 remains substantially constant and at a high value during movement of the arm 32 through the major portion of the angle through which it may berotated when the fusible element of the link 30 ruptures. This being true, it follows that even though the arm 33 is permitted to rotate partially away from the supporting arm 26 due to stretch of the pigtail conductor 3| and the fusible element of the link, the arm 33 will-nevertheless be rapidly rotated to effect are elongation and fuse remnant extraction when the fusible element of the link ruptures. Thus the described features all contribute to fast and positive removal of the pigtail conductor 3! from the fuse tube 25 when the fusible element of the link 30 is ruptured.

In the second embodiment of the invention illustrated in Fig. '7 of the drawings, substantially all of the above-described operating features are provided, together with modified facilities for effecting fuse tube dropout movement incident to fuse rupture. Aside from the structural differences pointed out immediately below, this embodiment of the invention "is exactly the same as that illustrated in Fig. 1 of the drawings and described above. Accordingly corresponding reference numerals have been used to identify corresponding parts of the two structures. In the modified construction, the two lower brackets i9 and 2|" are provided with trunnion seats Mia and Zia of only slightly greater diameter than the trunnions 26c and 2602 which permit rotation but not sliding movement of the trunnions. Fuse tube dropout movement is obtained by permitting collapse of a'hinge joint between the supporting arm 26 and the fuse tube incident to fuse rupture. Specificallmthe arm26 is provided with an enlarged end 40 hinged to the projecting nose 41a of the lower fuse tube ferrule 4| by means of a pivot pin 42. The enlarged arm end 40 is slotted as indicated at v43 to receive the ferrule nose Ma. In order normally to lock the arm 20; and ferrule 4| against relative pivotal movement, the extracting arm .33 is provided with a locking nose All which is adapted to seat within aligned nose receiving notches Mb, 400 and 4nd in the nose and arm parts Ma, 40a and 48b, respectively, when the tube 25 and arm 26 occupy correct relative positions for mounting upon the support In.

With .this construction, the locking nose 44 coacts with the pivot pin 42 to lock the fuse tube 25 and the supporting arm 26 against relative pivotal movement so long as the extracting arm 33 is held against the supporting arm 26 by the fuse pigtail conductor 3|. When, however, the fuse to which the conductor 3| extends is rupturedito permit downward movement of the extracting arm 33 under'the influence of the spring 20., the locking nose M is instantly withdrawn from'the notches 400, Mb and 40d, thus freeing the tube 25 and arm 26 for relative pivotal movement. This permits the tube 2.5 to move downward under the influence of gravity and the upper end spring thrust to disengage the tube end part '29 from the retaining element I4 and thus free the tube for dropout movement. Such downward movement of the fuse tube is accompanied by double pivotal movement of the supporting arm 26 about the axis of the trunnions relative to the support Ill and the pin 32 relative to the fuse tube 25.

While there have been described what are at present considered to be the preferred embodiments of the invention, it will be understood that various modifications may be made therein which are within the true spirit and scope of the invention as defined in the appended claims.

I claim:

1. A cutout of the dropout type comprising a support, a retaining element carried by said support, a fuse tube assembly including a fuse tube provided at one end with a part engageable with said element to restrain said assembly against dropout movement, a supporting member rigidly connected to said fuse tube and provided with pivot means, non-movab1e supporting means fixedly carried by said support for supporting said pivot means for pivotal movement and for translatory movement away from said retaining-element, said fuse tube, supporting member and.

pivot means being movable as a unit with respect to said supporting means to release said part from said element and thus permit pivotal dropout movement ofsaid assembly as said pivot means is translated away from said element, and fuse controlled means for normally preventing movement of said pivot-means away from said element.

2. A cutout of the dropout type comprising a support, a retaining element carried by said support, a fuse tube provided at one end with a part engageable with said element to restrain said assembly against dropout -movement and at its opposite end with supporting means rigidly mounted thereon, non-movable means fixedly carried by said support to slidably support said supporting. means for sliding movement away from said retaining element in a direction substantially transverse. to the axis of said tube, thereby to increase the distance between said supporting means and said element and thus permit dropout movement of said assembly without relative movement between said tube and said supporting means, and-fuse. controlled means for normally preventing said guided movement of said opposite tube end.

3. A cutout of the dropout type comprising a support, a retaining. element carried by saidsupport, a fuse tube assemblyincluding a fuse tube provided at one end with a part engageable with said element to restrain said assembly against dropout movement and a laterally extending supporting arm rigidly connected to said fuse tube and provided a with pivot means, non-movable means fixedly carried by said support to coact with said pivot means in providing for movement of said assemblylbodily relative to said support without relative movement between said fuse tube and said supporting arm, thereby to effect movement of said pivot means away from said element, said end part being released from said element to permit dropout movement of said assembly as said pivot means moves away from said element, and fuse controlled means for normally preventing said movement of said assembly.

i. A cutout of the dropout type comprising a support, a retaining element carried by said support, a fuse tube assembly including a fuse tube provided at one end with a part engageable with said element to restrain said assembly against dropout movement, a supporting member rigidly connected to said fuse tube and provided with pivot means, non-movable supporting means fixedly carried by said support for supporting said pivot means for pivotal movement and for translatory movement away from said retaining element, said fuse tube, supporting member and pivot means being movable as a unit With respect to said supporting means to release said part from said element and thus permit pivotal dropout movement of said assembly as said pivot means is translated away from said element, and spring biased fuse extracting means operative normally to prevent movement of said pivot means away from said element.

5. A cutout of the dropout type comprising a support, a retaining element carried by said support, a fuse tube assembly including a fuse tube provided at one end with a part engageable with said element to restrain said assembly against dropout movement, a supporting member rigidly connected to said fuse tube and provided with pivot means, supporting means carried by said support for supporting said pivot means for both pivotal movement and translatory movement away from said retaining element, said assembly being movable with respect to said supporting means to release said part from said element and thus permit pivotal dropout movement of said assembly as said pivot means moves away from said element, a fuse extracting arm pivotally supported by said supporting member and adapted for fuse restraint against pivotal movement relative to said supporting member, and biasing means carried by said support to coact with said arm in preventing movement of said pivot means away from said element and biasing said arm toward fuse extracting movement.

6. A cutout of the dropout type comprising a support, a retaining element carried by said support, a fuse tube provided at one end with a part engageable with said element to restrain said tube against dropout movement, a supporting arm rigidly connected to said fuse tube at the opposite end thereof and extending laterally therefrom, pivot means at the extended end of said arm, means carried by said support for supporting said pivot means for both pivotal movement and translatory movement away from said element, said tube and arm being movable as a unit to release said part from said element and thus permit pivotal dropout movement of said tube as said pivot means moves away from said element, a fuse extracting arm pivotally mounted upon said supporting arm adjacent the extended end of said supporting arm, said extracting arm being adapted for fuse restraint against pivotal movement relative to said supporting arm, and biasing means carried by said support to coact with said extracting arm in preventing movement of said pivot means away from said element and biasing said extracting arm toward fuse extracting movement.

7. A cutout of the dropout type compr" -g a support, a retaining element carried by support, a fuse tube provided at one ith a retaining part engageable with. said element to restrain said tube against dropout movem ent having an open opposite end from which an extractable fuse link canduotor is adapted to project, a supporting arm extending transversely away from the open end. of said tube provided with transversely spaced end parts at its extended end, bearing elements extending transversely of said arm outwardly from said end-v parts, an extracting arm adapted for connection with the projected end of a fuse link conductor and supported upon said supporting arm for pivotalmovement about the axis of said bearing elements, said extracting arm including'a camming' portion disposed between said end, parts, meanscarried by said support to. coact with said bearingelernents in providing for both pivotal movement of. said tube and translatory movement of said. bearing elements away from saidretaining element, said tube and supporting arm. being movable as a unit to release said retaining part from said retaining element and thus permit pivotal dropout movement of said tube as said bearing elements move away from-said retaining element, and biasing means carried bysaid supportand including a part coacting with said cam-- ming portion to prevent movement of said bearing elements away from said retaining element and-to bias said extracting arm for fuse extracting movement.

. 8., A cutout of the dropout type comprising a support, aretaining element carried by said sup port, a fuse tube provided at one end with a retaining part engageable with said element torestrain said tube against dropout movement and having an open opposite end from which an extractable fuse link conductor is adaptedto project,- a supporting arm extending transversely away from the open end of said tube and provided with transversely spaced end parts at its extended end, bearing elements extending transversely of said arm outwardly from said end parts, an extracting arm adapted for connection with the projected. end of a fuse link conductor and supported upon said supporting arm for pivotal movement about the axis. of said bearing elements, said extracting arm including a carn ming-xportion disposed between said end parts, spaced hinge brackets carried bysaid. supportand provided with bearing seats for supporting. said bearing elements for translatory movement in a direction substantially normal tothelongitudinal axis of said tube, thereby to provide for movement of said bearing. elements. away from saidretaining element, said tube and supporting arm being movable as a unit'to release. said retaining part-from saidretaining element and thus, permit pivotal dropout movement of. said tube as said bearing elements move away from said retaining element, and biasing means carried. bysaid support and including a partextending between said brackets to react between said support and said camming portion thereby normally toprevent movement of said bearing elements away from said retaining elements and. to. bias said fuse extracting: arm for fuse extracting movement.

9. A cutout of the dropout type comprisinga support, a retaining element carried by said support, a fuse tube provided at one end with a part engageable with said element to restrain said tube against dropout movement, a supporting member rigidly connected to said fuse tube and provided with pivot means, non-movable bracket means fixedly carried by said support and provided with bearing seats for supporting said pivot means for translatory movement therealong in a direction substantially normal to the longitudinal axis of said tube, thereby to provide for movement of said pivot means away from said element, said tube and supporting member being movable as aunit to release said part from said element and thus permit pivotal dropout movement of t4 said-:tubeas saidpivot means is translated away from said element, and fuse controlled means for normally "preventing movement of said pivot means :along: said seats.

10. A cutout of the dropout type comprisinga.

support, a retaining-element carried by said support, afuse tube provided at one end with a part engageable with said element tov restrain said tube against dropoutmovement, a supporting armrigidly'connected 'to said fuse tube at the opposite end thereof; and extending laterally therefrom, pivot .meansxat the extended end of said arm, bracketmeanscarried by said'support and provided withbearing seats for supporting said pivot uponsaid supporting arm adjacent the extended endxof said supporting arm, said extracting arm being-adapted for fuse restraint against pivotal movement relative to said supporting arm, and biasing means carried by said support to coact with saidextracting armin preventing movement of said pivot means along said seats and biasing said extracting arm for'fuse extracting movement.

11=.I'n= a fused cutout, a support provided with aipair otspaced brackets having aligned trunmon receiving openings therein, a fuse tube having-an openend'from which an extractablefuse link conductor is adapted to project, a supportingaa-rmextending laterally away from the open end of said tube 'and provided at its extended end with transversely extending trunnions engageablewithsaid brackets through said openings pivotally tosupport said fuse tube upon said brackets for rotation into closed circuit position, spring-"means carried by said support and including a part extending between said brackets, afiat strip extracting arm adapted for connection with the projected end of a fuse link conductor, and pivot means supporting said extracting arm'upon-said supporting arm for-pivotal movement about the axis of said trunnions, said fiat strip extracting arm being bent adjacent the pivotedend thereoft-o provide a camming surface engageablewith said spring part to tension the fuse link-conductor assaid fuse tube is rotated about the axisof" said trunnions into its closed circuit position 12. Ina fused cutout, a support provided with a. pair'of spacedbrackets having alignedtrunnion receiving seats therein, a fuse tube having an open end from which an extractable fuse link conductor is adapted to project, a supporting arm extending laterally away from the open end of said. tube :and: provided at its extended end with. transversely extending trunnions engageable-withsaidlseats pivotally to support said fuse tube upon said-brackets for rotation into closed circuitrzposition, spring means carried by said supportrandzincluding.a part extending between said brackets, a flat strip extracting arm provided at oneend with-a reversely bent portion. overlying.anz:intermediate'portion. of said arm", means oooperatingwitlrsaid two arm portions for se-- curely connectingthe project-ed end of a fuse link-conductor toisaid arm, and pivot means supporting saidextracting. arm. at the opposite.

end thereof upon said supporting arm for pivotal movement about the axis of said trunnions, said flat strip extracting arm being bent adjacent the pivoted end thereof to provide a camming surface engageable with said spring part to tension the connected fuse link conductor as said fuse tube is rotated about the axis of said trunnions into its closed circuit position.

13. A cutout of the dropout type comprising a support, a retaining element carried by said support, a fuse tube provided at one end With an end part engageable with said element to restrain said assembly against dropout movement, a supporting arm, hinge means pivotally connecting said supporting arm to said tube adjacent the other end thereof, said arm extending laterally away from said other end of said tube and being provided with pivot means at its extended end, an extracting arm pivotally supported upon said supporting arm and provided with a fuse controlled swing end co-acting with said hinge means normally to hold said tube and supporting arm against relative pivotal movement, bracket means carried by said support and coacting with said pivot means to support said fuse tube for rotation into closed circuit position wherein said tube end part engages said retaining element, and biasing means carried by said support and including a part engageable by said extracting arm as said tube is rotated into its closed circuit position to bias said extracting arm for fuse extracting movement, said hinge means being released in response to fuse extracting movement of said extracting arm to permit relative pivotal movement between said tube and supporting arm and thus provide for dropout movement of said fuse tube.

14. A cutout of the dropout type comprising a support, a retaining element carried by said support, a fuse tube provided at one end with an end part engageable with said element to restrain said assembly against dropout movement, a supporting arm, hinge means pivotally connecting said supporting arm to said tube adjacent the other end thereof, said arm extending laterally away from said other end of said tube and being provided with pivot means at its extended end, an extracting arm pivotally supported upon said supporting arm and provided with a fuse controlled swing end coacting with said hinge means normally to hold said tube and supportin arm against relative pivotal movement, said extracting arm being provided with a camming portion adjacent its point of pivotal support upon said supporting arm, bracket means carried by said support and coacting with said pivot means to support said fuse tube for rotation into closed circuit position wherein said tube end part engages said retaining element, and biasing means carried by said support and including a part engageable by said camming portion of said extracting arm as said tube is rotated into its closed circuit position to bias said extracting arm for fuse extracting movement, said hinge means being released in response to fuse extracting movement of said extracting arm to permit relative movement between said tube and supporting arm and thus provide for dropout movement of said fuse tube.

15. A cutout of the dropout type comprising a support, a retaining element carried by said support, a fuse tube provided at one end with an end part engageable with said element to restrain said assembly against dropout movement, a supporting arm, hinge means pivotally connecting said supporting arm to said tube adjacent the other end thereof, said arm extending laterally away from said other end of said tube and being provided with transversely extended end parts, trunnions extending from said end parts transversely outward from said arm, an extracting arm provided with camming means disposed between said end parts and with a fuse controlled swing end coacting with said hinge means normally to hold said tube and supporting arm against relative pivotal movement, pivot means supporting said extracting arm upon said supporting arm for pivotal movement about the axis of said trunnions, spaced brackets carried by said support and provided with seats for seating said trimnions, thereby to support said tube for rotation into closed circuit position wherein said tube end part engages said retaining element, and biasing means carried by said support and provided with a part extending between said brackets to engage said camming means as said tube is rotated into its closed circuit position, thereby to, bias said extracting arm for fuse extracting movement, said hinge means being released in response to fuse extracting movement of said extracting arm to permit relative movement between said tube and supporting arm and thus provide for dropout movement of said fuse tube.

16. For use in a fused cutout, a fuse pigtail extracting arm comprising a fiat strip adapted for pivotal support and having a pigtail extracting end removed from the point of pivotal support, said strip being provided with a return bent portion at its extracting end which overlies an intermediate portion thereof, and means extending from said intermediate portion of said strip and cooperating with said return bent portion for anchoring a fuse pigtail and for holding said pigtail in clamping engagement with said return bent portion of said element.

17. For use in a fused cutout, a fuse pigtail extracting arm comprising a flat strip adapted for pivotal support and having a pigtail extracting end removed from the point of pivotal support, said strip being provided with a return bent portion at its extracting end which overlies an intermediate portion thereof, said return bent portion having an opening therethrough, a tie post fixedly mounted upon said intermediate portion of said strip and extending through said opening, and a head mounted upon the extended end of said post, whereby a fuse pigtail may be wrapped around said post between said head and the return bent portion of said arm to be clamped between said head and the return bent portion of said arm.

18. A cutout of the dropout type comprising supporting means, a fuse tube assembly including fuse extracting means, means for mounting said fuse tube assembly upon said supporting means for dropout movement, and biasing means carried by said supporting means and engageable with said fuse extracting means to restrain said assembly against dropout movement and to bias said fuse extracting means for fuse extracting movement.

19. A cutout of the dropout type comprising supporting means, a fuse tube assembly including fuse extracting means, means for mounting said fuse tube assembly upon said supporting means for dropout movement, and biasing means carried by said support and including a part engaged by said extracting means as said assembly is moved into its closed circuit position to restrain said assembly against dropout movement and to bias said fuse extracting means for fuse extracting movement.

20. For use in a fused cutout, a fuse pigtail extracting arm comprising an elongated element adapted for pivotal support and having a pigtail extracting end removed from the point of pivotal support, said element being provided with a return bent portion at its extracting end which overlies an intermediate portion thereof, a tie post fixedly mounted upon said intermediate portion of said element and extending transversely past a part of said return bent portion of said element, and a head mounted upon the extended end of said post, whereby a fuse pigtail may be wrapped around said post between said head and the return bent portion of said element to be clamped between said head and the return bent portion of said element.

21. For use in a fused cutout, a fuse pigtail extracting arm comprising an elongated element adapted for pivotal support and having a pigtail extracting end removed from the point of pivotal support, said element having a curved camming portion disposed between said point of pivotal support and being provided with a return bent portion at its extracting end which overlies an intermediate portion thereof, a tie post fixed- 1y mounted upon said intermediate portion of said element and extending transversely past a part of said return bent portion of said element, and a head mounted upon the extended end of said post, whereby a fuse pigtail may be wrapped around said post between said head and the return bent portion of said element to be clamped between said head and the return bent portion of said element.

22. For use in a fused cutout, a fuse pigtail extracting arm comprising an elongated element adapted for pivotal support and having a pigtail extracting end removed from the point of pivotal support, said element being provided with a return bend portion at its extracting end which overlies an intermediate portion thereof, and means supported by said intermediate portion of said element to extend transversely of said return bent portion for anchoring a fuse pigtail and for holding the fuse pigtail in clamping engagement with said return bent portion of said element.

23. For use in a fused cutout, a fuse pigtail extracting arm comprising an elongated element adapted for pivotal support and having a pigtail extracting end removed from the point of pivotal support, said element having a cu ved camming portion disposed between said point of pivotal support and said extracting end and being provided with a return bent portion at its extracting end which overlies an intermediate portion thereof, and means supported by said intermediate portion of said element to extend transversely of said return bent portion for anchoring a fuse pigtail and for holding the fuse pigtail in clamping engagement with said return bent portion of said element.

said brackets as said fuse tube and supporting member are pivoted about the axis of said trunnions to move said retaining part into engagement with said retaining element, and spring biased cam engaging means carried by said support and including a part extending between said brackets to engage said camming means and prevent translatory movement of said trunnions along said bearing seats after said tube. and supporting member have been pivoted to effect engagement of said retaining part with said retaining element.

25. In a fused cutout of the dropout type, an elongated support, a retaining element carried by said support adjacent one end thereof, a fuse tube provided at one end with a retaining part engageable with said element to restrain said tube against dropout movement, a supporting member mounted on said tube adjacent the opposite end thereof and provided with trunnions laterally displaced from said tube, spaced brackets fixedly mounted upon the other end of said support to extend away from said other end of said support and provided with elongated bearing seats for supporting said trunnions for pivotal and translatory movement, curved camming means on said supporting member positioned to move toward said brackets as said fuse tube and supporting member are pivoted about the axis of said trunnions to move said retaining part into engagement with said retaining element, and a U -shaped spring having one leg mounted upon said other end of said support and the other leg extending between said brackets to engage said camming means and prevent translatory movement of said trunnions along said bearing seats after said tube and supporting member have been pivoted to effect engagement of said retaining part with said retaining element.

EDWARD I-I. YONKERS.

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

UNITED STATES PATENTS Number Name Date 2,133,139 Hermann Oct. 11, 1938 2,199,908 Birkenmaier May 7, 1940 2,235,666 Birkenmaier Mar. 18, 1941 2,362,314 Schultz et a1. Nov. 7, 1944