US1114340A - Non-renewable fuse. - Google Patents

Description

R. C. COLE.

NON-RENEWABLE FUSE. 'APPLICATION FILED 11,411.17, 1913.

R. C. COLE. NON-RENEWABLE FUSE. APPLICATION FILED MAR. 17, 191s.

Patented Oct. 20, 1914.

2 SHEETS-SHEET 2.

AROBERT C. COLE, OF HARTFORD,

Ycitizen of 'the 4United States,

UNTTED sTATEs PATENT oFFicE.

coNnEcTIcUT, nssrsnon To THEJoHNs-PRATT com- ZPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

noN-EENEWABLE FUSE.

' Fuses, of which the following isa specification. l This invention relates to the construction of inclosed electric safety fuses hayng single and multiple fusible links of the ferrule,

' lug and knife blade terminal types.

disrupted .means Itis requiredA that Electric fuses are essentially intended to be safety devices. They are designed to be placed inV circuits and to open on an abnormal'rise of current and thus protect apparatus connected-'with the circuits and yobjects adjacent to thecircuits and the fuses. If theydo not blow'when the conditinsb'ecome dangerous they are not safety devices.

`Mii'ch thought and study has been given and much labor and expense-has been incurred in order to devise fusesthat will blow accurately/under the predetermined conditions and thus be dependable .safety tliefusible elements be inclosed in (order-to eliminate the dangers of the opening of the circuits when the fusible elements melt. Fusible elements that are inclosed cannot be seen. To` save expense unscrupulous persons and those not skilled in the art frequently after a fuse has blown, inserta new fusible element in place of the one. that has been destroyed. As a result it often happens that fusible elements of a capacity not warranted by ther conditions have been placed in fuses and because thevelements could not be seen these have been passedas safety devices, on the assumption that the elements were of the proper capacity and of the rating stated on the fuses, whereas, as a matter of fact the `fusible elements were of so vmuch greater' capacity that the fuses instead of being safety deidce's were an element of danger.

The object of this invention is to so construct an inclosed fuse that after the fusible element originally placed therein has been or destroyed, the structure cannot be disassembled or manipulated'in such ay manner that another fusible element can be placed in the interior. To attain this object the fuses are so manufactured that the terminals after once assembledl cannotbe removed witliout destroying or causing visual I. -Shpeciication of Letters Patent. A l' lamination med march 1,7, 1913.

vcut in central .Fig. t shows verse section on Awith b-y solder 4, or

Patented oct. 2o, 1914.y .seria1No.754,e22.

damage-to the structure, or cannot be drilled or cutand a fusible element passed through the -inside and connected with the terminal so as to complete the circuit through the interior.- The onlywa'y that a fuse which e'mbodies thisinv'ention can be made use of after it has `beenblown is by connecting the terminals by a link which passes over the exterior, a" condition which instantly shows that the'fuseis iiot in its original state.

I Figure 1 ofthe accompanying drawingsy is a side View with' part cut in'centralfsection of-a single link inclosed fuse of the ferrule terminal type which embodies the invention. Fig 2 shows a similar view vof a fuse of thesame type which' is constructed according to this invention and is vented in such manner as lto permit the escape of gases developed by the blowing of the '-fuse, the vent openings being arranged in such manner that it is practically impossible to pass a' fuse wire through them from one terminal to the other. Fig. 3 is a side view with part section of a multiple link inthe vknife blade terminal type. a transverse section taken on the plane'indicated by the dotted .line 41-4 onFig. 3, looking in closed fuse of the direction indicated by the arrows. Fig. 15 is a side View with a part cutin central section of a multiple link inclosed fuse of the knife blade terminal type having a different construction fromthat shown inv Figf. lFig. 6 shows a transtlie plane indicated by the dotted line 6-#6 on Fig. 5, looking-.in the direction indicated bythe arrows.

The fuses shown have nonsconducting `casiugs l which-are desirably made of tubular pieces of 'vulcanized fiber.vv In the form first shown metallic end caps "2 are forced on the ends of the casing. may be made ofbrass or steel, as desired, and their inner edges are crimped into the casing as at 3 so that after .once being set they cannot be withdrawn. v The closed ends of these caps are inset and connected thereanv other desired means are the internal terminals 5 to which the vends of the fusible element '6 are secured.

In the recessed ends of the caps-are steel disks 7. These disksv are case-hardened or made extremely hard in any other desired manner so that they cannotbe punched, drilled or otherwise cut. Itis desirable to locate brass disks 8 outside of the hard 'steel These end capsv disks and to hold these in place by spinning or otherwise turning the outer edges 9 of the caps over the edges of the disks. As a result of this construction, after a fusible element become disrupted the end caps cannot-be removed without destroying the casing and the steel disks cannot be perforated so as to permit a fusible element to be run through from one terminal .to the other. v

1f it is desired to provide vents for the escape of gases when the fuse blows, openings 10 may be made through the end walls of the caps. In this case instead of using a flat hardened steel disk, as shown in Fig. 1, the hardened steel disk may be cupped as is the disk 11 shown in Fig. 2. Vent openings 12 may be made through cup. The cupped disk'is secured by turning over the outer end of the cap. This disk is hardened so that it cannot be perforated and the vent openings are in such osition that itis impossible to push a wire t rough them and through the casing and out through the vent openings at the other end and thus electrically connect the terminals together in the interior.

In the form shown in Figs. 3 and 4 the knife blade terminals 13 are connected with an anchoringspider 14 that tits Within the casing. The internal terminals 5 of the fusible element 6 are connected with this spider which is attached to the external terminals. On .the outside ofthe ends of the casing tight-fitting ferrules 15 are driven. These ferrules are desirably tapering and can be made of steel or brass, as desired, preferably the former. After these ferrules have been forced to place, pins 16 are driven through them and the casing and terminalanchors. These pins securely hold the terminals and the ferrules in Vplace on the ends of the casing. Felt washers 17 may be placed over the ends of the casing and felt rings 1S may be placed around the ferrules. Ove-r these .are placed hardened steel caps 19,l which after being located have their inner edges turned in over the edges of the ferrules that are held on by the pins. When the edges of the caps are thusturned in ,the parts cannot be removed for the caps cannot bedrawn from the ferrules and the ferrules and terminal anchors cannot be removed becausethey are held by the concealed pins'. The front turned in edges of the hardened steel caps are preferably provided with openings 20. vVhen a fusible element blows the gases can` pass through the pores of the washers 17 and rings 18 and escape through these openings in the ends of the caps and thus relieve the pressure in the interior.

In the forms shown in Figs. 5 and 6, hardened steel ferrules 21 are driven on the ends of the casing and ,secured in place by the pins which pass through the ferrules, the

the sides of thisv casing and the arms of the terminal anchors. The front edge of this ferrule is turned up at 23'and on the fer-rule is tightly set the end cap 24. The pins lcannot be drivenroutv as` they are concealed so that they ferrules cannot be removed and the steel non-drillable caps are set so tightly on the ferrules that they cannot be removed without destroying or materially damaging the structure.

The' invention claimed is:

1. An inclosed fuse having a fusible element, a casing inclosing said element and tool-resisting disks of the hardness of hardened steel permanently attached to and.

protecting the ends of the casing, whereby perforations cannot be easily cut from the exterior' to the interior through said protecting disks to permit the insertion of a fusible element without substantial damage to the structure.

2. An inclosed fuse having a fusible element, a casing inclosing said element, and

tool-resisting means of the hardness of hardened steel with vent openings permanently attached to and protecting the ends of the casing, whereby openings cannot be Amade from the exterior to the interior through said protecting means for the insertion of a fusible element without destroying the structure.

' 3. An inclosed fuse having a fusible element, a casing inclosing said element, and

tool-resisting disks ofthe hardness of hardened steel permanently attached to the ends of the casing and protecting the ends of the fusible element whereby openings cannot be made from 'the exterior to the interior through vsaid protecting disks for the insertion of a fusible element without destroy- Aing the structure.

4. An inclosed fuse having a fusible element, a casing inclosing said element, and hardened steel parts permanently attached to and protecting the ends of the casing so as to render it diiiicult to perforate the protected ends of the casing for the renewal of the vfusible element.

5. An inclosed fuse having a fusible element, a casing inclosing said element, an means closing the ends of the casing, said means having hardened steel parts permanently attached to 'and obstructing the openings into the ends of the casing, whereby openings cannot be made into the ends of the casingfor the insertion of a fusible element without destroying the structure.

6. An inclosed fuse having a fusible element, a casing inclosing said element, ferrules on the ends of said casing and hardened steel disks permanently attached to the .ferrules and protecting the ends of said cas- An inclosed fuse having a fusible element, a casing inclosing said element, and

hardened steel end Capsl permanently attached to the ends of said easing, whereby openings oannot be readily drilled` through said end caps from the exterior' into the ends of the casing so as to permit the insertion of a Conducting,` element without substantial and ,apparent mutilation of the structure.

8. An inclosed fuse having a fusible element, a easing inclosing said element and a tool-resisting disk of the hardness of hardened steel permanently attached to and proteoting one end of the casing, whereby perforations cannot be easily out from the eX- terior to the interior through said protect i ing` disk to permit the insertion of a fusible element without substantial damage to the structure, and means permanently closing the other end of the casing.

9. An inelosed fuse having a fusible element, a casing inelosing said element, and a hardened steel end cap permanently attached to one end of said casing, whereby. openings cannot be readily drilled through said end Cap from the exterior into the und of the easing so as to permit the insertion of a conducting element Without substantial and apparent mutilation of the stl-nei tui-e, and means permanently closing the other end of the easing.

ROBERT C. COLE. lVitnesses JOSELHINE M. STREMPFER, HARRY R. VILLIAMS.

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