US1380556A - Fused cut-out - Google Patents

Description

A. HERZ. .FUSED CUT-OUT.

APPLICATION FlLEDjUG-IO. 1917.

Patented June 7, 1921.

A. HERZ.

FUSED (lUT-OUT'. APPLICATION FILED Aue.1o. 19n.

Patented June 7, 1921.

5 SHEETS-SHEET 2.

A. HERZ.

FUSED CUT-OUT.

APPLICATION FILED AUG-1:10. 1917.

Patented June 7, 1921.

5 SHEETS-SHEET 3.

A. H ERZ. F-USED GUI-OUT. APPLiCATlON FILED AUG- 10/1917.

Patented June 7, 1921.

5 SHEETS-SHEET ,4.

A. HERZ.

FUSED CUT-OUT.

APPLICATION FILED AUG-I01 I917.

Patentedlune 7, 1921.

5 SHEETSSHEI:T 5

Ilium L l W ii il UNITED STATES PATENT oFFIcE,

ALFRED HERZ, OF CHICAGO, InLIivoIs, ASSIGNOR on ONE-HALF T0 EDMUND o.

scnwnrrznn, on CHICAGO, ILLINOIS.

InsEn GUT-OUT.

Specification of Letters Patent.

Patented June 7,1921.

Applicatien fiieii August 10, 191?. seen no. 185,567.

T 0 all whom it may co /Loam.

Be it known that I, ALFRED Hnnz, a citizen of theUnited States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Fused Cut-Outs, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part i of this specification.

My invention relates to the like.

In Patents Nos. 1,033,123 and 1,144,732 granted to Edmund Schweitzer and my self jointly, and a, in Patent No. 1,222,952 granted to me solely, there are described successive steps of the development of a form of fused cut-out which employs a fuse, and compression blocks upon opposite sides of the fuse. These blocks are forced in by springs when the fuse softens and tend to fused cut-outs and smother and to chill or even prevent the are which tends to form. I

The present invention is' a further improvement on that type of fused cut-outs.

I have employed in practice the structures described and claimed in the above patents up to substantially their limits of capacity. I have found that within the limits for which they are designed they are efiicient and reliable but in order to obtain greater capacity for interrupting current flow I have found it ne'ces'sary'to introduce certain novel structures and principles for overcon'li'ngthe greater liberation of energy. As the heat of the melting fuse or are is roughly proportionalto R1 it will be appreciated that theenergy to be dissipated increases on'the order of the square of the current to be interrupted, consequently a mere increase in size of the parts of the cutout very quickly fails to keep pace with the requirements of increased current interrupting capacity I employ ano'vel principle of arc extinguishing as will be apparent from the" following. a I V I provide compres ion blocks on opposite sides of the fuse and submerge the fuse and blocks in oil, The compression blocks are spring pressed against two sides of the fuse and thus tend to choke off or even prevent formation of the arc assoon asthe fiise softens. The oil fills the space alongthe sldes of the fuse and fills the space between the overhanging sides of the blocks. The 011 prevents the escape of v apors which might be suificiently conductive to reestablish an are outside of the blocksfthis is especially desirable in view of the high volt age of the circuits to which this form of device is adapted, I h q According to my invention I provide a motion-limiting device for the blocks to limit the outward movement ofthese block s when the fuse blows. This tends to throw the force of the fuse explosion upon the body of oil. Unless the oil can also be limited in movement or forced tochoke off the arc, the arc may blow out sidewise and establish itself under the oil in the manner-in which a plain fuse oil operates; I provide means for creating a ressure of the oil. The particular me'ans employ is a tight casing lab out the entire device which is nearly filled with oil. When the fuse blows it automatically increasesthe pressure of the oil. These two limiting actions tend to prevent the formation of an arc and tend to extinguish quickly an arc that may be formed. The blocks chill the metal. v r a d s th r thearq- T oil tamps" the fuse and .the pres si ire created 1 by the are explosion forces the'oil in upon the arc to extinguish same. On alternating current the pressu're of the oil easily extinguishes the arc when the current value passes through zero to reverse as it does at each half cycle.

e iir fe he 6 1 a be m ed taijned constantly under pressure or may be otherwise made to exert a pressure for extinguishing the are or for maintaining the proved structural features which arepointed out more particularly in the appended claims.

In order to acquaint those skilled in "the art with the manner of making and practising the invention, I shall now describe in detail a specific embodiment of the inven tion.

In the accompanying drawings which form a part of the specification Figure 1 is a top plan view of the cutout and hanger with certain parts broken away for the sake of clearness;

Fig. 2 is a side elevation of the same;

Fig. 3 is a front elevation of the lug on the lid of the casing shown in Figs. 1 and 2;

Fig. 4 is a fragmentary sectional view of the casing showing the nipples for leading in the connecting cables;

Fig. 5 is a side elevation of the movable cut-out element showing the handle, the shield, the compression block, fuse and contacts;

Fig. 6 is an elevation of the stationary element of the cut-out showing the base block of insulation and the stationary contact element;

Fig. 7 is a plan view of the blank from which the stationary contact is manufactured;

Fig. 8 is a plan view of the fuse;

Fig. 9 is a side elevation of the detachable compression blocks showing the spring catches;

Figs. 10 and 11 are different forms of vents for the casingsfor relieving excessive pressure;

Fig. 12 is a fragmentary cross section through the casing, the base block, the compression blocks and the fuse;

Fig. 13 is a horizontal cross sectional view generally on line 13-13 of Fig. 14; and

Fig. 14 is a vertical cross sectional view of, a modified form of easing, showing the inner parts in plan and elevation, respectively.

Figs. 1 and 2 illustrate the preferred form of casing and hanger.

The working parts within the casing are:

the same throughout the figures.

The fuse 1 which comprises a small fiat strip of soft metal, such as an alloy of tin and zinc or aluminum and some other metal, is connected at its ends to the movable or plunger contacts 2 and 3 by means of the screws 4 and the clips 5. The opposite fiat faces of the fuse 1 are engaged by the limestone blocks 6 and 7 which are mounted upon the removable backing block 8 and the carrier or plunger block 9, respectively. Flint or quartz may be used instead of limestone for the blocks 6 and 7. The contacts 2 and 3 which are carried on the edges of the plunger or carrier block 9 are stamped out of sheet metal and are-provided with arms 10 and 11 suitably notched to receive the cooperating spring catches 12 and 13. The spring catches 12 and 13 are pivotally mounted upon the backing block 8. Pins 14; limit the movement of the spring catches of its proper position.

12 and 13 which press the backing block 8 and the carrier block 9 together, thus compressing the fuse between the compression blocks 6 and 7. The carrier or plunger 9 extends upwardly and is provided with a suitable U-shaped handle 15 by which the block 9 is manipulated. The handle 15 has its legs 16 extending down along the edges of the block 9 to which these legs are secured.

A circular disk 17 forms a shield for the hand of the operator, this shield being secured to the top of the block 9 as by means of the angle brackets 18 and 19. The movable contacts 2 and 3 which are mounted on the plunger 9 are adapted to engage with the stationary contact brackets 22 and 23.

The stationary contact brackets 22 and 23 have their shorter legs secured to the base block 25 at the under surface thereof and the longer legs 26 and 27 extend through slots 28 and 29 in the base member 25 and have their upper ends clamped under the binding posts 30 and 31. These stationary contact brackets 22 and 23 are of a general U-shape, with the contact members 20 arranged at the bottom of the U.

Fig. 7 shows the blank stamped out of sheet metal for constructing the contact bracket with the contact attached. The contact 20 is formed of a pair of lugs 33 and projecting from opposite edges of the 7 bottom of the U, these lugs are slit as is shown at 35 and 36 to increase the flexibility so that a larger area of contact is secured. A pair of small lugs 3738 project from the side edges of the lug 33 and these small lugs are bent around the edges of the lug 34 when the lug 34 is bent up intoparallelism with the lug 33. They are adapted to prevent accidental bending of the lug 34 out They also insure entry ofthe movable contacts 23 centrally of the corresponding contacts 22 and 23.

The ends of the legs of the U-shaped blanks are bent at right angles as indicated on the dotted lines 40 and 41. This permits motion of the stationary contacts 22 and 23 with respect to each other to a sufiicient extent to accommodate themselves to the movable contacts 2 and 3 thus insuring easy in sertion and removal of the carrier or plunger 9. The shape of the bracket is such as to brace the contact in the other direction and thus insure the requisite permanency.

In addition to serving as a supporting base for the relatively stationary contacts 22 and 23, the base block 25 performs the very important function of limiting the movement of the compression blocks 6 and 7. The center of the base block 25 is suitably apertured to receive the plunger or carrier 9 and the backing block 8. At the back of the plunger 9 the base block 25 approaches very closely, being separated only by the small gap 42'which is ample clearance for the insertion of'the carrier element and its connected parts;

l0- -ll-and the spring catches 12- 13. The

backing block 8 is separated at its center from the base block- 25 for a small clearance 47 which limits. lateral movement of the backing block and the-corresponding compression block.. The ends of the compres sion block 8 lie very close to-the base block 25 being separated only by the small clear ances 48 and 49. As-aconsequence the movement of thecompression blocks 6 and7is: limited by the encircling base block 25. It is apparent that separate means may be employed for limiting the movement of the compression; block'but I find-that the ar rangement indicated is ideal because of the fact that these surfaces'which limit move-' ment of the compression block alsoserve as guides during insertionof the plunger member, as .well as supporting the stationary contacts 22 and 23.

The baseblock 25'is provided with a circumferential groove 50 and in this groove I provide a winding of piano wire 51 serving as a hoop to reinforce the base blockJ25.

against the bursting effort of theblocks8 and 9 when they are forced outwardly. A split ring 52 is laid in the groove 51 and this ring is secured to the casing 53 as by means of screws 25 may be mounted in the casing as by means of bayonet slots and pins or other known means. The incoming conductors 55 and 56 (see Fig. 13) are connected to the binding posts 30 and 31 as by means of set screws 57. To prevent accidental connection being made between these binding posts I provide a shield or barrier 58 ofinsulation betweenthese binding posts and the aperture in the base block25. Thusiti is impos-.

sible to make contact between the projecting lugs 11 and the binding posts 3031 by incorrect insertion of the plunger 9. This barrier 58 is supported from the base block 25 as by means of the angle brackets 60 and screws 60. These screws are shown in section in Fig. 13 the barrier 58 and brackets being removed for the-sake of clearness.

In Figs. 1 and 2 I have shown the pre ferred form of casing for inclosing the working parts. This casing consists of a pot orbowl shaped casing 61 having a drain plug 62 in the bottom thereof.z1Tl1e upper edge of the pot isprovided witha flange 63 which cooperates'with. the flange of the lid 64. Suitable leading-in nipples 65 and 66 are arranged in line with each other near the rearof the shell61; These nipples are 54. It is apparent that: the block:

shown in section in 4. They are pro- 7 vlded with internal grooves 1 67. A suit able insulating thimble' having corrugated outer surface is insertedfrom the outside into the opening in the nipple and wax or cement is poured in between the corrugations -ofthe insulating sleeve and the grooves 67 thus holding the parts firmly in place. Suitable supporting lugs 68 and 69 are formedintegral with the casing or shell 61 and the nipples 6566, these lugs being perforated and adapted to be slipped over-the pins 70-71 on a separate supporting bracket 72. The supporting bracket 72 1 is adapted tobe fastened in place on a crossarm :or on a switchboard panelorthe like and the cut-out casing isthen mounted upon the bracket by slipping thelugs 68 and 69 over the pins 70-71 and resting the body of the'casing 61 against the extending prop or support 73 which holds the lower part of the casing 61 in the correct position. Cotter pins 74are passed throughthe ends of the pins70-71 and thus the cut-out is nrmlyhungin position. The lid 64 is provided with strengtheningribs 75 which eX-; tend to the rear of the device and are loosely hinged to suitable hinge brackets 76 as may be seen in Figs. 1 and 2. 1 The cover 64- is clamped down upon the top of-the casing 61- by means of a pair of claws 77 and 78, these claws having suitably shaped hooks at their extremities as is shown at 79 infFi'g';

2,-so that "as the claws 77 and 78 are drawn together by means of the screw bolts 80 and threaded handle 81 they cause the lid to be firmly wedged down upon the flange 63.

The screw bolt 80 is providedwith' a square head 82 having a rounded under surface83 which permits the bolt to center itself with respect to the claws77. The square head 82 prevents turning of the bolt when the handle 81 is'turned. The bolt 80 passes through a central lug 84 formed on top of the lid 64 and suitable coil springs 85 and 86 are interposed between this lug 84and the claws 77 and '78. These springs push the claws outward when the handle isturned to release the bolt. The lug 84 is provided with a pin 87 which forms a suitable eyeforraising the lid 64.

The casing 61 is provided with a vent or safety valve 88 which releases when the pres sure within the casing 61 becomes too great. This vent is illustrated in Fig. 11 and consists of a casing 89 having a valve seat 90 normally closed bya ball valve 91. The ball valve 91 is normally pressed on its seat by means of the spring 92. The spring 92 is In Fig. 10 I have shown a modified form of vent. The nipple 96 at its inner end communicates with the inside of the casing 61 and at its outsideend is closed by a membrane or diaphragm 97 heldon the end of the nipple by means of an aperture cap 98. Excessive pressure blows out the membrane or diaphragm 97 thus affording release. The membrane 97 may be made of such a thickness that it will yield and thus give an indication of the blowing of the fuse. This,

however, is not always desirable.

The casing or shell illustrated in Figs. 13 and 14 is provided with a lid 100 held down upon the flanges 101 by means of the bolts 102 and wing nuts 103. It is understood in each case that a suitable gasket is placed between the lid and the corresponding flange. The lid 100 is provided with a handle 104. The casing 53 is suspended upon bracket arms 105 formed integral with the walls of the casing. These bracket arms are slotted as shown at 106 in Fig. 14 so that the bolts which ar to support the device may first be fastened in place and then the brackets hooked over the bolts 107 by means of the slots 106. I

In Figs. 13 and 15 I have indicated the manner in which an overhead cable 108 may be led into the casing 53 as shown at the right of these figures. The casing 53 is provided with hollow lug or boss 109 having a suitable opening for receiving the porcelain bushing 110. After the conductor 56 is secured in place the bushing 110 and the hollow boss 109 are closed off by means of the cement or wax 111. The bushing 110 may be made of any suitable insulating material. At the left of Figs. 13 and 14 I have illustrated a manner in which lead covered cables such as are used underground may be led into the casing 53 of the cut-outdevice. For this purpose the hollow lug or boss 112 is threaded as shown at 113 to receive the wiping sleeve 114, which sleeve is then united to'the lead sleeve 115 of the cable,as by means of the wiped joint 116 shown in Fig.

14. The different ways of leading in the conductors or cables may be varied as desired the above instances showing the adaptability of the construction for any particular use.

The operation of the device is as follows:

Assuming that the casing 61 or 53 is properly mounted and that the conductors are connected to the binding posts, the interior of the casing is substantially filled with oil or other suitable insulating li uid to about the broken line indicated at 11 in Fig. 14. This body of oil is suificient to cover the binding posts, the stationary and movable contacts, the fuse and the compression block. The plunger member with the connected parts is then inserted in place so that the contacts 2 and 3, between which well known the fuse l is connected, are in proper electrical contact with the stationary contacts 22 and 23. It is to be noted that the stationary contacts 22 and 23 are I in effect sockets and the upper edges of the lugs which form these sockets are bent-outwardly soas to aid in properly alining the stationary and movable contacts. The cover or lid isthen put in place and clamped down to render the casing substantially fiuid'tight.

The space between the upper surface of the the fuse and the immediately adjacent part.

Such heat as escapes through the compression block and the backing block moves very slowly due to the poor conductivity of these parts. Consequently "the ratein rise of the overload does not appreciably affect the ratingof the fuse as is the case in the usual oil submerged fuse. When the overload current melts the fuse 1, the springs 12 and 13 push the backing block 8 and the compression block 6 in to choke out and damp theme which tends to form... At the same time the oil is squeezed out'from between the blocks 6 and 7 but it prevents the escape of any vapors which might tend to reestablish the flow of current if the oil were not present.

substantially an explosive effect. The backing block 8 strikes against the base block 25 on one side and. the plunger block 9 strikes 3 against the base block on the other side, thus limitingthe space within which the arc is formed. The escape of any vapors from the space between the compression blocks 6 and 7 serves to raise the pressure within the casing thereby tending to force the oil into the space between the blocks to extinguish the The movement of the compression block is limited mechanically and the movement of the oil is limited by the liquid pressure'so that the greater the tendency to generate vapor so much greater will be the tendency of the oil to press in and extinguish the arc. F urther-the tendency for an arc to maintain itself is discouraged due to the phenomena of the snufling out tendency'of hlgh fluid pressures on electric arcs.

The motion limiting action which the base springs 12, 13.

block 25 performs prevents damage tothe When the fuse 1 has blown the carrier block 9 may be removed by opening the lid of the casing and pulling upward on the handle 15.

I do not intend hat the invention shall be limited to theprecise details of construction shown and described. Y

I claim V 1. In combination a fuse, compression blocks lying on opposite sidesof the. fuse, means pressing the compression blockstoward each other, a movable carrier menber, contacts mounted on said carrier member, said contacts being electrically connected to said fuse, means for limiting the motion of the compression blocks away from each other and relatively stationary contact members mounted on said motion limiting means.

2. In combination, a base member, stationary contacts mounted on said member, a movable carrier element having contacts for engaging said stationary contacts, a fuse connecting the relatively movable contacts, compression blocks on opposite sides of the fuse, means pressing said blocks against the sides of the fuse. said base member having means for limiting the movement of the compression blocks away from each other.

3. In combination, a base block having an aperture therethrough, relatively stationary contacts mounted on the lower side of said base block, a plunger member adapted to be inserted through said aperture, said plunger carrying plunger contacts for engaging the relatively stationary contacts, a fuse connecting said plunger contacts, compression blocks on opposite sides of the fuse, spring means for urging the compression blocks tward each other, the walls of the aperture in said base blocks being so formed as to guide the plunger contacts into position and to limit the outward movement of the compression blocks with respect to each other.

4. In combination a casing, a base block of insulation secured on the inside of said casing, relatively stationary contacts secured to said base block on the lower side of the same, said base block having an aperture therethrough, a plunger member adapted to enter said aperture, said plunger member having plunger contacts for engaging said rslat re y s a ion ry ontacts a fusc--b tween said plunger contacts, compression blocks on opposite sides of the fuse and means, to press said blocks against said fuse,

said base block having means to limit said compressionblocks in their movement with respect to each other.

5. V In combination, a base block having an aperture therethrough, a U-shaped bracket jmounted on ,the lower side of: said base In combination, a base block havingan aperture therethrough, a Urshaped contact bracket adjacent each sideof the aperture upon the lower surface of said block, a carrier block having contacts at the sides thereof adapted, to cooperate with said U-shaped contact brackets, a fuse connected between the contacts onsa1d, carr erblock and w1res connected to, said U-shaped contact brackets theapelg'turein said base block serving as a gulde for said carrier block, when the contacts are brought into engagement with the contact brackets.

7 In combination, a carrier block having contacts on the edges thereof, said contacts extending down below said block, detent arms extending from the side edges of the contacts, a compression block mounted on said carrier block transversely thereof, a backing block having springmeans for engaging the detent arms, said backing block having a compression block parallel with the first compression block, and a fuse connecting said contacts, said fuse lying between the compression blocks.

8. In combination, an apertured base block, a pair of U-shaped contact brackets, one of the legs of each bracket lying in a narrow slot, binding posts mounted on the upper surface of the base block'and con necting with the corresponding legs of the U-shaped contact brackets, said contact brackets having contacts forming sockets adjacent the edges of the aperture, and a plunger member guided by said aperture, said plunger member having contacts thereon connected by a fuse and engaging said contacts on the contact brackets.

9. A contact bracket comprising a flat U- shaped stamping of metal, having lugs projecting on opposite sides at the bottom of the U, said lugs being bent into parallelism and forming a contact socket, and the end of one leg of the U being bent at substantially right angles to form attaching means.

10. In combination, a base block having an aperture therethrough, relatively stationary contacts upon the one side of the base block adjacent the edges of the aperture, a

plunger adapted to be guided by said aperture, said plunger having plunger contacts adapted to engage the relatively stationary contacts, a fuseconnecting said plunge-r contacts, binding posts on said base block and a barrier of insulating material between the binding posts and the aperture.

11. In combination, a plunger block, a U- shaped handle, a disk forming a hand shield, said disk being apertured and angle brackets between the U-shaped handle and the disk, the legs of the U-shaped handle passing through the disk and being secured to the plunger block.

12. In combination a fuse, a pair of compression blocks lying on each side of said fuse, means for forcing the compression blocks toward each other, means for limiting the movement of the compression blocks away from each other, a body of oil inclosing said fuse and said compression blocks, and a substantially fluid tight casing inclosing the body of oil. i 13. In combination, a fuse, a compression block lying'on one side of said fuse, a block lying on the other side of said fuse, means for'forcing said blocks toward each other, contacts secured to one of said blocks, a handle connected to one of said blocks, means for limiting the movement of said blocks away from each other and stationary contact means mounted on said motion limiting means.

14. In combination a base member, stationary contacts mounted on said member,

a movable carrier element having contacts for engaging said stationary contacts, a fuse collecting the relatively movable contacts, compression blocks on opposite sides of the fuse, means pressing said blocks against the sides of the fuse, said base blocks having means for limiting the movement of the compression blocks away from each other, a casing inclosing the above named elements, and a body of: oil in which said elements are submerged which body of oil substantially fills said casing.

In witness whereof, I hereunto subscribe my name this 7th day of August, A. D. '1917.

ALFRED HERZ.

It is hereby certified that in Letters Patent No. 1,380,556, granted June 7 1921,

upon the application of Alfred Herz', of Chicago, Illinois, for an improvement in Fused Cut-Outs, errors appear in the printed specification requiring correction as follows: Page 5, line 53, claim 3, for tward read toward; page 6, line 38,

claim 14, for the word collecting read connecting; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 28th day of June, A. D., 1921.

KARL FENNING,

Acting Oommtssioner of Patents.

[SEAL]

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