US2138769A - Indicating fuse plug - Google Patents

Description

Nov. 29, 1938. H. M. MUNCHERYAN 2,138,769

INDICATING FUSE PLUG Filed Jan. 27, 1937 2 Sheets-Sheet l Insuurnon INVENTOR HPand M. Mun ch EPHHTI BY ATTORNEY.

Nov. 29, 1938.

H. M. MUNCHERYAN 2,138,769

lNDICATTNG FUSE PLUG Filed Jan. 27, 1957 2 Sheets-Sheet 2 9 I INVENTOR. 69 67 7/ Hrand M. Muncheryan PMQJM A TTORNEY.

Patented Nov. 29, 1938 UNITE STATES PATENTv OFFiCE INDIGATING FUSE PLUG Hrand M. Muncheryan, Los Angeles, Calif.

Application January 27, 1937, Serial No. 122,588

15 Claims. (Cl. 200-130) My invention relates to a fuse plug of the genof insulation that are utilized for supporting the oral type disclosed in United States Letters Patnd cat g fus in position Within the P .ent No. 2,067,977 issued to me January 19, 1937, Fig. 8 is a vertical section similar to Fig. 2 and the principal objects of my invention are and showin a modified term of he se and also 5 to generally improve upon and simplify the cona modified arrangement of Supporting the fuse 5 struction of the plug disclosed in my aforesaid Within the p patent, as well as other forms of similar fuse Fig. 9 is a perspective View with parts broken plugs, and to provide improved means for indiaway and showing a part of the fuse supporting eating the condition of the fuse, that is, whether means that is utilized in the form of plug illus- 10 or not the fuse has been blown or ruptured as a trated in Fig. 8. 10 result of overload of current in the circuit in Fig, 10 is a plan view of a modified form of which the fuse plug is located. the fuse supporting means.

A further object of my invention is to provide 11 is a oss Se t on ta en On the line an improved form of device that carries means, of g. either integrally or separately formed, for indig- 12 s a V w looking against he u ders de 15 eating the condition of the fuse, and spaced por- 0f the form of fuse mounting illustrated in Figs.

tions of said fuse adjacent and beyond the con- 10 and 11 With Parts broken y d in S edition indicating means being restricted or made tiOIlnarrow or thin, to form definite points that fuse 13 is a P p e V O a o st uct o and rupture when the fuse is subjected to an that y be utilized Supporting a portion o 20 overload of current, v the fuse condition indicating means within the A further object of my invention is to provide D Chamber- 7 means for supporting the fuse in position be- 14 is a p p V w Of a urther modified neath the window or transparent area in the top form of y improved indicating e P of the plug and to arrange the electrical connec- Fig. 15 is a vertical cross section taken on the 25 tions between the contacts of the plug and the line f fuse so that the current carri d by the fuse and 16 s a p pe e V ew Of one form of the connections is caused to positively pass through indicating fuse used in the p the thin or narrow portions of the fuse, thus ig. 17 is a pe p V Of a modified form bringing about the rupture or blowing of the fuse 0f the indicating fuSeat the restricted points so as to release and de- 13 is a p ew Of a modified form of stray th t portion t t carries t condition p the fuse and the condition indicating characters eating characters. By removing or destroying arried thereby that portion of the fuse that carries the fuse con- 5115- 19 a cross Section taken on the line dition indicating characters, an observer, by notlgflg of 35 ing the absence of such characters beneath the 15 perspectlve VleW showmg the nection between a current carrying member and an insulated disk, and which construction is used in certain forms of the indicating fuse plug.

Fig. 21 is a plan view of a further modification of the indicating fuse plug.

Fig. 22 is a plan View of the form of plug illustrated in Fig. 21, and showing the fuse blown or ruptured at two points so as to expose the underwindow of the plug, will readily understand that the plug is unfit for further service.

With the foregoing and other objects in view my invention consists in certain novel features of construction and arrangement of parts that will be hereinafter more fully described and claimed and illustrated in the accompanying drawings, in

whlch: lying member of the plug indicating means 45 Fig 1 1s a top plan of a fuse plug Fig. 23 is a cross section taken on the line 23 structed in accordance with my invention, 23 of Fig Fig, 2 is a cross section taken on the line 2--2 Fjg 24 5 2 27 and 23 are plan views f of Fig. 1. modified forms of fuses that are adaptable for Fig, 3 is a top plan view of the fuse plug with use in my improved indicating fuse plug. 50 parts broken away and in section and showing Referring by numerals to the accompanying the fuse blown or ruptured at two spaced points drawings, and particularly to the construction so as to entirely release the fuse condition indiillustrated in Figs. 1 to 7, inclusive, 10 designates eating characters. a fuse body of conventional form and composed Figs. 4:, 5, 6 and '7 are perspective views of disks of insulating material such as glass, porcelain or 55 composition, said body having a chamber I I, and mounted on the exterior of the intermediate portion of the body is a shell I2 of metal in which is pressed a thread in order that the plug may be screwed into the conventional socket.

Located in the lower end of the body of the plug and extending into the lower portion of chamber II is a contact I3 that is adapted to engage the center contact of the socket in which the plug is positioned.

The upper portion of the chamber I I is slightly enlarged with respect to the lower portion, thus forming an internal shoulder I4 in the upper portion of said chamber, and positioned on top of the plug and providing a cover for the chamber II, is a disk I5 of transparent material, preferably mica, that is held in position by a metal rim I6 that encircles the upper end of body ID. The section of mica I5 provides a window whereby the fuse that is positioned in the enlarged upper portion of the chamber II may be readily observed.

Resting on shoulder I 4 is the edge of a thin disk II of insulation and formed at diametrically opposite points in the edge thereof are notches I8 and positioned above and spaced apart from said disk I? is a second disk I9 of insulation pro vided in its edge with diametrically opposite notches 20 that are adapted to register with the notches i8, and formed at or near the center of disk I9 is an aperture 2| (see Figs. 4 and 5).

In some instances the disks I! and I3 may be provided at diametrically opposite points with slots or apertures 22 that coincide with each other when positioned in the plug above the shoulder I4, and said slots or apertures performing the functions of the notches I8 and 20 (see Figs, 6 and 7).

Positioned on top of disk I! is a thin strip of metal 23 that functions as a conductor, and the outer end of said conductor extends through an aperture 24 in the wall of the plug and this end of the strip is electrically connected to the shell I2.

The inner end of conductor 23 extends upwardly through an aperture 2| in the upper disk I9 and the end of said strip above said disk is bent downwardly so as to lie flat on the upper surface of said disk I9.

One end of a strip of metal 25 that functions as a conductor and a fuse is electrically connected to the center contact I3 and said strip extends upwardly to a point beneath the center of disk II and then extends at right angles outwardly against the underside of said disk, thence upwardly through the coinciding notches I8 and 20 on one side of the disks I! and I9, thence diametrically across the upper disk I9, thence downwardly through the opposite pair of notches 20 and I8, thence beneath the disk I! and the end of this portion of the strip is provided with ears 26 that are bent around and beneath the edges of that portion of the strip that lies beneath the disk I1, and which extends at right angles from the substantial upright portion that is connected to contact I3.

The general form of this combined conductor strip and fuse is illustrated in Fig. 17.

As illustrated in Fig. 1, the intermediate portion of that section of the conductor and fuse that extends across disk I9 and which is in direct contact with the end of conductor 23 that lies flat on the center of disk I9, is formed with fuse indicating characters, for instance, the letters OK, the same being cut from the metal forming the fuse and conductor, and the sides of these characters are connected to the main body of the fuse and conductor by relatively narrow portions 21, and which latter are ruptured or blown in the event of an excess or overload of current through the plug.

In Fig. 17 I have shown the intermediate portion of that section of the fuse and conductor that overlies the disk I9, in the form of a plate 28, and fuse indicating characters, for instance, the letters OK or the word Good may be marked or stamped on the upper surface of said plate.

To retain the disks II and I9 in proper position within the fuse plug with the edge of the lower disk I1 resting on the shoulder I4, a spacing ring or collar 29 of insulating material is positioned between the edge of disk I9 and the under face of the transparent disk I5.

The construction just described provides for the rupturing or blowing of the fuse at two points to the sides of the indicating characters that form a part of the fuse and thus when the fuse ruptures or blows as a result of overload of current, the indicating characters or that portion between the narrow connections 21 will be freed and distorted and drop so that an observer may readily note that the fuse has blown and therefore is unfit for further service.

Where this form of fuse is blown or ruptured as a result of overload of current, said current passes from contact I3 through that portion of the conductor 25 that is connected to said contact, thence through one end of a loop of which the indicating characters form a part, thereby rupturing one of the narrow portions 2'! and immediately current passes through the other end of the loop and blows or ruptures the other one of the narrow connecting members 21, thus freeing and distorting the characters or that portion of the fuse between the narrow connections 21.

In the modified construction illustrated in Figs. 8 and 9, the construction of the body of the plug is practically the same as that heretofore described and illustrated in Figs. 1 to 3 inclusive, and resting on the shoulder I4 within the plug is a single disk 30 of suitable insulating material provided in its edge at diametrically opposite points with notches 3 I, and formed in the center of this disk of insulation is an aperture 32.

Connected to the center contact I3 located in the bottom of the plug body is one end of a strip of metal 33 that functions as a conductor, and the upper end of this strip is provided with a horizontal C-shaped plate 34 that rests against the under face of disk 30 around the opening 32 therein.

Projecting inwardly from the ends of the C-shaped plate 34 and thence upwardly through the aperture 32 and thence outwardly on top of disk 30, are contact ears 35.

Overlying the disk 38 is a combined conductor and fuse indicating strip 35 formed of metal, the end portions thereof extending through apertures 31 formed in the wall of the plug, and said ends being electrically connected to the threaded shell I2 on the surface of the plug.

The intermediate portion of the conductor 36 is in direct contact with the ears 35 and this portion of the fuse is formed with indicating characters, for instance, the letters OK or said intermediate portion may be in the form of a plate bearing the letters OK or the word Good.

In this form of plug portions of the strip 39 to the sides of the fuse indicating characters or the plate that bears such characters, are reduced in width or thickness as designated by 38, so as to define the points at which the fuse blows or is ruptured in the event of an overload of current.

In the modified construction illustrated in Figs. 10 to 12 inclusive, a disk 39 of insulation overlies a lower disk 46, and formed at diametrically opposite points on the edge of disk 39 are notches 4|, and extending inwardly from thecenters of said notches are narrower notches 42.

Formed at diametrically opposite points in the edge of the lower disk 46 are notches 43 that coincide with the notches 4| in the upper disk and passing through the notches 4| and 43 are the end portions of a strip of metal 44 that functions as a conductor and a fuse condition indicating member.

The intermediate portion of the upper member of the loop 44, or that portion that extends across the top of disk 39, is cut to form fuse condition indicating characters, for instance, the letters OK, and a portion 45 of the strip extends from the bottom of the loop 44 beneath the lower disk 49 downwardly, and this portion is electrically connected to the center contact in the bottom of the plug body.

Extending diametrically between the disks 39 and 40 is a conductor strip 46 of metaL'the ends of which are bent upwardly through the narrow notches 42 in the upper disk 39 and the ends of this strip are extended over the upper face of said upper disk 39 to provide contacts that engage the overlying portion of the loop 44.

This conductor strip 46 is electrically connected to the threaded shell on the exterior of the plug by a narrow strip of metal 41.

Formed in the side edges of the overlying portion of conductor strip 44 beyon the fuse condition of conductor strip 44 beyond the fuse condisame being located just beyond the ends of the conductors 46 that lie on top of disk 39, thus forming relatively narrow portions 49 in the fuse strip, and which portions are ruptured or blown in the event of overload of current through the plug.

In the modified construction illustrated in Figs. 14 and 15, the plug body 50 having a chamber 51, is provided at its upper end with a window 52, at its lower end, with a center contact 53, and on the surface of the intermediate portion of the plug is a threaded shell 54.

Formed through the upper portion of the wall of the plug is a passageway 55 that is occupied by the vertical leg of an inverted L-shaped metal conductor 56, the lower end thereof being electrically connected to shell 54. The horizontal leg of this conductor 56 extends horizontally into the upper portion of the chamber within the plug between two disks or sections 57 of insulating material. The inner end of the horizontal leg of the conductor 56 extends upwardly through the upper one of the disks of insulation and this end is bent'downwardly to lie flat on the upper surface of said upperdisk.

One end of a strip of metal 58 that functions as a conductor and fuse condition indicating character, is connected to contact 53 and extends upwardly and the upper portion of said strip is formed into a loop 59 that encircles the disks 5'! of insulation, with the upper portion of said loop in direct contact with the end of the conductor 56 that lies on top of the upper disk.

That portion of strip 58 that overlies the upper end of the disks 51 functions as a fuse and, as illustrated in Fig. 16, this, portion may be formed with fuse indicating characters such as OK, or

this particular portion may be in the form of a plate having marked on itsupper surface fuse indicating characters.

Portions of the conductor 58 to the sides of the fuse condition indicating characters, are made narrow, as designated by 66, in order to provide spaced points beyond said characters where the fuse blows or ruptures in the event of an overload of current.

In Fig. 13 I have illustrated a construction. wherein a pair of conductors 6i extend upwardly in the. chamber within the plug, the lower ends of which conductors are connected to the center contact 53. The upper ends of said conductors are bent to form horizontally disposed hooks 52 that receive and hold an inserted card or piece of insulation 63 bearing on its upper face characters to indicate that the fuse has blown, for instance, the word Bad. Where this construction is used it is not necessary to use in the upper portion of the chamber of the plug disks of insulation such as I1, 23 and 39.

A fuse such as 36 or 58 carrying fuse indicating characters such as OK or Good overlies and extends lengthwise of the member with portions of the body of the fuse beyond the condition designating characters making direct contact with the upper portions of the ears 62.

ms, when the fuse blows or is ruptured as a result of overload of current, the condition indicating characters forming a part of or carried by the fuse, will drop away from their normal positions so as to expose the section of insulation 63 that is marked with characters showing that the plug is unfit for further service.

In the modified construction illustrated in Figs. 18 and 19, the intermediate portions of a conductor fuse 64 formed of thin metal, has portions 65 folded over the ends of a card or section of insulation 66 bearing on its upper surface fuse condition indicating characters such as OK. That portion of the fuse between the bent portions 65 extends beneath the card 66 and portions of the conductor fuse just beyond the bent portions 95 are made narrow to provide points where the fuse ruptures in the event of an overload of current, thus freeing the fuse condition indicating card or member 66.

In the modification illustrated in Figs. 21 to 23 inclusive, the loop portion 610, of a conductor fuse practically identical with the form of conductor fuse illustrated in Fig. 17, passes around an upper disk 6'5 and a lower disk 53, both of insulating material. This loop is connected to one of the contacts of the plug and the intermediate portion of the upper member of the loop is in the form of a plate 69 on the upper surface of which appear fuse indicating characters, for instance, the word Good, or the letters OK.

This plate 69 is connected to the body of the conductor fuse by narrow portions if! which rupture in the event of an overload of current through the fuse.

Appearing on the upper face of the upper disk 61 and concealed as long as the plate 69 is in its normal position, are fuse indicating characters, for instance, letters forming the word Bad, and which letters are exposed when the fuse is ruptured and the overlying plate 69 drops away from its normal position.

Interposed between the disks 6'! and 99 is a conductor II that is connected to one of the con tacts of the plug, and the ends of said conductor extend upwardly through notches or apertures in tor make direct contact with the conductor 66 at points just beyond the narrow portions 70 of the upper member of the loop.

In Figs. 24 and 25 I have illustrated modified forms of the fuse wherein that portion that is disposed between the narrow points where the fuse is ruptured in the event of an overload of current bears on its upper face data relating to the capacity of the fuse in amperes.

In Fig. 26 I have illustrated the conductor fuse having a portion cut to form condition indicating characters 72, for instance, the outline of the letters OK and when the material forming the fuse is bent over a strip of insulation along the lines a:x, these letters appear on top of the strip without displaying the adjacent portions of the fuse.

Portions of the letters 12 are made narrow to form definite points where the fuse ruptures in the event of an overload of current, and such rupturing obviously destroys the fuse condition indicating characters so as to show that the plug in which the fuse is located is unfit for further service.

In Fig. 27 I have illustrated a form of fuse wherein the fuse condition indicating character bearing plate 13 is disposed at right angles to the main body of the fuse.

In Fig. 28 I have illustrated condition indicating characters such as the letters OK integral with and on the sides of the main body of the conductor fuse.

Thus it will be seen that I have provided an indicating fuse plug that is relatively simple in construction, inexpensive of manufacture and very effective in performing the functions for which it is intended.

In all cases the construction of the plug and conductor fuse is such that in the event of an overload of current through the plug the fuse is caused to rupture or blow out at two or more spaced points, thereby releasing and practically destroying a substantial portion of the fuse, and which portion bears fuse condition indicating characters, and thus after a fuse has blown an inspection of the plug will readily and positively indicate that the plug has been ruptured and therefore that it is unfit for further service.

It will be understood that minor changes in the size, form and construction of the various parts of my improved indicating fuse plug may be made and substituted. for those herein shown and described without departing from the spirit of the invention, the scope of which is set forth in the appended claims.

I claim as my invention:

1. The combination with a fuse plug having a chamber and a window, of a conductor fuse arranged within the chamber in the plug and having a portion positioned adjacent the window in said plug, said portion bearing fuse condition indicating characters, and means for causing said conductor fuse to rupture at a plurality of points so as to release and destroy that portion of the fuse bearing the fuse condition indicating characters.

2. A conductor fuse having a portion constituting a closed loop and a conductor portion leading from said closed loop, a portion of said loop hearing fuse condition indicating characters and said loop having restricted portions positioned adjacent the ends of that portion bearing the fuse condition indicating characters.

3. The combination of a fuse plug having a chamber, a window and electrical contacts, of a fuse arranged within the chamber in said plug, a portion of said fuse being positioned adjacent the window in the plug and bearing fuse condition indicating characters, said fuse having a plurality of restricted fusible portions located beyond that portion that bears the fuse condition indicating characters, an electrical connection in relation with the fuse-condition indicating characters and one of said conductor contacts positioned in close relation with said characters but in remote relation with said restricted fusible portions to determine the points where the fuse ruptures in the event of an overload of current therethrough, and electrical connections between the contacts of the plug and said fuse to cause the fuse to rupture at the restricted points in the event of an overload of current through said fuse.

4. The combination of a fuse plug having a chamber, a window and electrical contacts, of a fuse arranged within the chamber in said plug, a portion of said fuse being positioned adjacent the window in the plug and bearing fuse condition indicating characters, said fuse having a plurality of restricted portions located beyond that portion that bears the fuse condition indicating characters to determine the points where the fuse ruptures in the event of an overload of current therethrough, electrical connections between the contacts of the plug and said fuse to cause the current to rupture at the restricted points in the event of an overload of current through said fuse, and a second indicating means, positioned beneath that portion of the fuse that bears the fuse-condition indicating means, being disclosed thereof after the first fuse-condition indicating means is released and destroyed as a result of an overload of current, and thereby indicating that the fuse is unfit for further service.

5. In a fuse plug, having a chamber, a window, and a fusible element having a portion adjacent said window, a plurality of fusible narrow portions extending from the said portion adjacent the window, said portion adjacent the window constituting fuse condition indicating means and means including a contact and a conductor for supporting said fusible element adjacent said window.

6. In a fuse plug having a chamber, a window, and a pair of electrical contact terminals, a fuse element disposed in said chamber in the plug and bearing fuse-condition indicating means, a plurality of insulating plates located beneath the said window, a portion of said fuse element extending through said insulating plates and exposed to a portion of the electrical contact terminal causing an electrical connection between the said contact terminals of the fuse and said condition indicating means and insulating the rest of that portion of the fuse element which occupies the said plug chamber from the said contact terminals.

7. In a fuse plug, having a chamber, a window, and electrical conductors consisting of a shell and an upright center contact, a fuse element having a portion adjacent said window, said portion having fuse condition indicating means and having its ends electrically connected to the said shell restricted, fusible portions on each side of said fuse condition indicating means, and means whereby said fuse-condition indicating portion of the fuse makes electrical connection with said center contact and is supported thereon in an indicative position.

8. A conductor fuse having portions forming current-carrying fuse-condition indicating characters and portions of said characters being restricted to form definite points of rupture as a result of overload of current, said conductor fuse having extensions at each end of the said indicating characters and adapted to support said indicating characters and to retain the indicating characters in spaced relation in order to cause flow of current only through the reduced portions of the said characters.

9. The combination with a fuse plug having a chamber and a window, of a conductor fuse arranged within the chamber in the plug and having a portion positioned adjacent said window, said portion bearing fuse-condition indicating characters, and current conducting means connected to the ends of said spaced fuse-condition indicating characters so as to divide the course of the current through the said indicating characters into a plurality of current carrying paths corresponding to the number of restricted portions of the fuse condition indicating characters.

10. In a fuse plug, having a chamber, a window and a pair of spaced contacts electrically connected together by means of a fusible conductor in the said chamber, said fusible conductor having integral current-carrying fuse-condition indicating characters adjacent said window, and ourrent-limiting narrow fusible portions located at the extremities of the said indicating characters and forming a portion of the path of the current through the said fuse-condition indicating characters.

11. In a fuse plug, a conductor fuse having means for indicating the normal condition of operation of the said fuse and having, a plurality of restricted portions positioned adjacent said fuse-condition indicating means and adapted to rupture in the event of an overload of current through the fuse, and electrical conductors connected to said fuse condition indicating means and dividing the current between said restricted portions.

12. In a fuse plug, a conductor fuse having means for indicating the condition of said fuse,

and a plurality of restricted fusible portions connected to said fuse condition indicating means for dividing the course of the current into same number of current paths as there are restricted portions, and permitting said fuse condition indi cating means to be released and destroyed upon an overload of current through the said fuse and its restricted portions.

13. In a fuse plug having a chamber, a window, and spaced terminal electrical contacts, a fusible conductor connecting said spaced contacts, said fusible conductor bearing means for indicating the normal operative condition of the fuse and located adjacent said window, said indicating means having spaced reduced portions adapted to rupture as a result of an overload of current and portions adapted to make electrical connection with one of the said terminal contacts and supported in upright operative position thereupon.

14. A conductor fuse having portions forming current-carrying fuse-condition indicating means cut from said conductor to form current-conducting characters and portions of said characters being restricted in cross sectional area to define points of rupture when said fuse is subjected to an overload of current, said defined points of rupture constituting portions of said characters forming the path of the current through the fuse.

15. In an article of manufacture, a fusible element a portion of which constitutes fuse-condition indicating characters, fusible restricted por-- tions located in proximity of said indicating means, extensions from each of said restricted portions and forming diiferent current paths thereof, a number of said extensions making electrical connection with portions of the fuse circuit having like electrical polarity, and the rest of said extensions making electrical connection with portions of the circuit having a polarity opposite to that of the first.

HRAND M. MUNCHERYAN.

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