US1689424A - Fuse - Google Patents

Description

v 30 fully exposed Patented Oct. 30, 192,8.

ITED STATES A '1,689,424 PATENT OFFICE..

:NICHOLAS J. coNaAn, or WILMETTE, ILLINOIS, AssIeNOa To scnwnITzna a CONRAD,

ING., or cIIIoAGO, ILLINOIS, A OORPORATION'OI ILLINOIS. l

rusa.

Application led Kay 17,

My 'invention relates to uses, v particularlyto the type such as disclosed in 'Conrad Patent 1,220,152' of March 20, 1917, or Schweitzer & Conrad Patent Number 1,319,-

907 Of'October 28, 1919, inwhich type a transparent housing usually inthe form of a glass tube is used for enclosing the fuse and circuit rupturing parts and the arc extinguishing liquid.

Glass is a very desirable material Jfor enclosing the circuit controlling parts of the fuse structurey as it has the necessary mechanical strength, 'is sufficiently electrically resistant, resist-s chemical 'attack by i5 the arc extinguishing fluid, and is transparent so that the contents of the glass housing can always be observed. Hereto-.

fore, plaln uncolored glass has been used and such uncolored glass has disadvantages which it is the important Object of my present invention to overcome. Arc extinguishing fluid, particularly carbon tetra chloride has a tendency to attack substances, particularly metal, and such action is greatlyA ina5 creased in the resence of light. The fuses to which my invention apply are used in connection with high voltage transmission linesY where the transformer or substations are out in the open so that the fuses are to the weather and to full sunlight. This intense light can readily pass through the uncolored glass and will hasten deterioration of the are extinguishing fluid and its action on metals and other substances within the fuse structure. The chemical Or actinic rays o f light are the ones which cause such action of the fluid, such rays pass readily throughuncolored glass.

I have found that by using colored glass, 0 as for example, green, red, orange, Or ruby colored glass, these chemical or harmful rays are intercepted and prevented from iniluencing the arc extinguishing fluid.

In Order to illustrate the application of my invention I have shown aV use structure on the accompanying drawing. On the drawing, 'y Figure 1 is a side elevational view of a fuse structure partly in vertical diametral v section; andl Fig. 2 is a top view. Briefly describ'ng the structure, 1 represents the enclosing glass tube which has at its lower end the terminal cap 2 and at its upper end the terminal cap structure 3, these has the diametral slot 20 for receiving fthe 192s. seriai No. 109,814..

cap structures being rigidly sealed to the tube end. The lower cap structure has the vaxial lug 4 which is threaded to receive the Vthe lower end of this upper terminal post.

The tension spring 10 is anchored by means of pin 11 to the collar 12'which is secured to the lower terminal post 5 as by means of a screw 13. At its upper end the spring is secured byv pin 14 to the collar'15 which is secured by screw 16 to upper terminal post 8. -On the interior annular shoulder 17 formed on the terminal cap 3 above the end ofv lthe tube 1 rests the annular support 18 75 for the washer 19, this washer being of in; sulating material such las bakelite. The upper ond of the upper terminal post 8 extends into and is slidable in the washer 19 and BI) fuse structure 21 which is secured at its diametrical opposite ends to the cap structure 3 by means of the screws 22. This fuse structure may be of the ty e disclosed in m co-pending application erial No. 32,- 740 filed May 25, 1925, and normally holds the upper terminal postS in its upper position against the pull of the spring 10. Above the fuse structure the annular recess 23 in the cap structure 3 seats the vent cover 24 which with the adjacent walls of the cap structure 3 forms the explosion chamber 25 above the fuse structure. The tube 1 is filled with arc extinguishing fluid 26 such as carbon tetra chloride and this'liquid 10 normally extends up to the washer 19. l

The fuse structure is placed in service with its terminal caps in engagement with the terminals of a circuit to be protected, and upon abnormal current low through the circuit, the fuse structure 21 will fuse and the upper terminal post 8 will be released whereupon the spring 10 will forcibly draw down the upper terminal post and with it the plunger 7. The plunger vhas the annular convergent or nozzle passageway around the upper terminal ost so that when the plunger is Iforcibly sud only drawn downwardly in the tube 1 the extin ishing fluid will be squirted upwardly vio ently to effectively ex- 11o t-inguish and destroy any arcing which might tend to take place after rupture of the fuse structure .and downward movement of the upper terminal post.

Some fluids, as for example, halogen dervatives of hydro-carbon, and particularly carbon tetra chloride, have a tendency to attack metals and other materials and this action is greatly increased and hastened in the presence of strong light. Where the fuses are placed in dark places, such action is not so noticeable, but fuses of the types described are used in outdoor substations or transformer stations and are exposed directly to strong sunlight, and under such conditions of service a fluid such as carbon tetra chloride is under a disadvantage, and the increased activity in attacking materials in contact therewith and its tendency to disintegrate, detract from the eiiiciency and reliability of the fuse structure. The actinic or chemical rays of light are the ones which cause such action of the fluid, and where the glass of the surrounding tube 1 is uncolored, these rays may readily pass through. Other material besides glass could be used lwhich could keep out light entirely, but glass on account of its transparent quality is Very desirable as it permits inspection of the fuse working part at all times. I therefore make it possible to retain the use of glass and to still rotect the contained fluid against the actinic rays of light by using colored glass or by applying coloring material to the primarily uncolored glass. I find that with green, red, orange, or ruby colored glass the actinic rays will be suiiiciently intercepted or rendered harmless, although there may be other colors which will serve the same purpose. Such coloring will not interfere with vision through the glass for inspecting the interior of the fuse structure at any time. The association of a color medium with the fluid will protect it even in the strongest sun or other light.

Having described my invention, I claim as follows In a device of the class describedya pair of fuse terminals, a fuse element connected between them, a spring for moving one of said terminals away from the other when the fuse melts, a iiuid tight casing for said element, said casing including a pair of external terminals and an intermediate glass tube within which the spring is disposed, a bath of are extinguishing liquid in said casing, said arc extinguishing liquid comprising a halogenderivative of a hydrocarbon which is normally inert, but which, under the action of light, disintegrates and attacks the fuse, changing its capacity, said glass tube having embodied therein a substance which screens out the rays that tend to disintegrate the liquid` but permits suliicient visible light to pass therethrough to permit the position of the spring to be seen to determine whether the fuse has blown or not.

In witness whereof, I hereunto subscribe my name this 15th day of May, 1926.

' NICHOLAS J. CONRAD.

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