US1761054A

US1761054A - Renewable fuse

Info

Publication number: US1761054A
Application number: US199047A
Authority: US
Inventors: Walter H Schrupp
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-06-15
Filing date: 1927-06-15
Publication date: 1930-06-03
Anticipated expiration: 1947-06-03

Description

W. H. SCHRUPP RENEWABLE FUSE June 3, 1930.

Filed June 15, ,1927

Patented June 3, 1930 UNITED STATES WALTER H. SCHRUIPP, OF GRANITE FALLS, MINNESOTA RENEWABLE FUSE Application filed June 15,

The present invention relates to improvements in renewable fuses and more particularly to that type of fuse commonly knownas tubular fuses and of that character as em ployed as a protector for telephone systems.

With the usual type of tubular fuse as now employed in connection with telephone systems, the fusible element is soldered at both ends to the metallic ends of the fuse shell or barrel, and thus necessitates that the fuses be returned to a repair shop for the renewing of the fuse when blown.

It is therefore a primary object of the present invention to provide an improved tubular fuse embodying features whereby a new fuse may be readily inserted into the fuse shell and connected with the metallic ends of the shell merely by employment of a wrench or a pair of pliers and thus allowing the fuse to be renewed at its mounting location in a very short time and without requiring that the fuse be transmitted to a repair shop in order that the terminals of the fusible element may be connected with the metallic ends of the fuse.

A further object of the invention is to provide a renewable fuse of the tubular type embodying means whereby the fusible element may be readily inserted through the tubular shell of the fuse and be coupled as by means of suitable nuts to the metallic ends of the fuse.

A further object of the invention is to provide a renewable fuse having metallic heads so constructed and associated with the tubular shell of the fuse as to permit of the fusible element to be readily associated with the fuse without requiring removal of the heads for proper positioningof the fusible elementlon gitudinally within the tubular shell.

A. still further object of the invention is to provide a renewable fuse of the tubular type which may be very economically manufactured and one wherein fragmentary portions of the blown fuse element may be readily removed from the tubular shell prior to insertion of the new fuse.

Other objects and advantages of the invention will be apparent during the course of the following detailed description taken in connection with the accompanying drawing 1927. Serial No. 199,047.

forming a part of this specification and in which drawing:

Figure 1 is a side elevation of the improved renewable fuse.

Figure 2 is a view showing the various elements constituting the fuse and showing the shell and heads of the fuse assembled and in longitudinal section.

Figure 3 is a central longitudinal section through the fuse and showing the fuse wire in position. i

Figure at is a plan view of the upper end of the fuse as illustrated in Figure 2.

Figure 5 is an end view of the lower end of the fuse as illustrated in Figure 2.

In the drawing, and wherein similar reference characters designate corresponding parts throughout the several views, the improved fusehas been shown as embodying a tubular main body portion or shell 10 which is formed of a suitable insulating material such as fiber or the like, and with the bore of the shell being of equal diameter throughout the length of the shell.

The insulating shell or main body portion 3 10 is provided with upper and lower metallic ends or heads 11 and 12 respectively, and which heads serve as coupling means for the terminal portions of the fuse wire 13 which is adapted to extend through the tubular shell 10.

The metallic head 11 and which is intended to be connected with the upper end of the shell 10 embodies a plug portion 14: of a diameter to be snugly inserted into the upper end of the shell, and the outer end of the plug portion is provided with an annular fiange or shoulder 15 from which extends in axial alignment with the portion 14, an externally screw'threaded extension or stem portion 16 of a diameter less than that of the flange 15.

Thus it willbe seen; that the annular flange 15 forms an annular outwardly facing seat 17 at the inner or lower end, of the screw thread-- ed extension 16. As will be observed in Figures 2 and 3, the flange 15 abuts with the upper end of the shell 10 and thus limits inward movement of the head. The head 11 is provided with an axially extending bore 18 which as will be observed extends axially- Gil Til

through the plug portion M and extension 16, and this bore is flared into a bell shaped mouth 19 at the inner end of the head with the wall of the mouth terminating in the circumference of the plug portion 14; so that no shoulder or abutment is formed at the inner end of the plug portion such as would prevent ready upward movement of the fuse wire through the bore of the head. The head 11 may be secured in the shell 10 in any preferred manner and in the example shown diametrically arranged pins 20 e? through the shell and plug portion for retention of the head in coupled relation to the shell. The externally threaded extension or stem 16 provided with a longiteulinally ex:- tending slot 21 which extends to. oughout the length of the stem and opens into the he. 18 is clearly illustrated in Figures 823 l. It will he observed that the here it; is relatively large diameter and it may here he well lo state that the object in so having the bore 18 as large as possible without wea ening the stem 16 to an undesirable (h will allow for a relatively large openin' ing formed into the here of the tubular 10 for allowing any fragn'ientary portion a blown fuse wire to he removed through bore 18.

Referring now to the metallic end or head 12 for connection with the opposite or lower end of the shell 10, the same inclurrs a plug portion 22 which is readily insertihle into the bore of the shell and is provided at its outer end with an annular flange or shoulder forming an outwardly facing seat 24- and projecting from the seat 2l in axial alignment with the plug 22 a threaded shank 25. The head 12 may be retained in coupled relation to the shell 10 as by means of suitable diametrically arranged pins 26 which pass through the shell 10 and into the plug portion. 22. The inner end of the plug 22 is provided with a flaring pocket 27 prowld with a rounded bottom 28. will he so this flaring pocket 27 merges at its mouth p tion into the circumference of the plug portion 22, and is of a depth substantially half the length of the plug portion. Extend ng (JILL in angular relation to thcoaxis of the head '12 from the rounded bottom 28 of the pool to the seat face 24 to one side of the eircrunference of the shank 25, is a passageway 29 forming commui'iication between the hero of the shell and the head seat 24.

A washer 3O slidably fits over the threaded extension 16 and

nuts

31 and 32 are threaded along the extension over the washer 30, wnile a washer 33 is intended to be slidable over the shank 25 and followed by a clamping nut 34.

lVhen desiring to renew the used wire, the nuts, together with the washers are ii-stremoved from the heads 11 and 12 and one end of the fuse Wire 13 is inserted through the seat 24 in a manner passageway 29 and will be guided tlnrough the bore 18 of the head ll. by the flaring mouth 19 until the terminal. portion which has been inserted through the shell projects for a slight distance past the outer end. of the threaded extension ill and the opposite terminal of the wire extends past the outwardly facing seat of the head 12. The projecting lower end of the wire may then be wound about the shank adjacent the illustrated in Fi ures .1 and Z-land then the washer 23 and nut all positioned on the shank so that tightening of the nut will .lirmly clamp the lower )1 t rminal of the fuse wire between the .rasher and seat The upper projecting terminal of the fuse wire is then drawn through the slot 21 and. wrapped about the base portion of the threaded extension 16 upon the seat 1'? and after which the washer All) and nut 31 may he applied to the extension for firmly clamping the to dual of the fuse *ire between-the washer 39 and flange 15. Thus it will be seen that the terminals of the fuse wire are ehectively connected with the metallic heaus at the opposite ends of the insulating shell 10 without the necessity of soldcring the terminals of the wire to the heads, and that no strain imparted to that portion of the fuse wire ex: nding through the shell during clamping of the terminal portions of the fuse wire to the metallic ends.

It will further be noted that the improved manner of connecting the terminal portions of the fuse wire to the terminal portions of the fuse body does not increase the external diameter of the tubular shell and thus allows for the fuse to he used at locations and installed in a manner as are the tubular fuses new in neral use in connection with telephone systems.

newahle features whereoy'the fusible element is effectively connected at its end to the termi- Froni "-e foregoing d 'ipliion it will he apparent that an improved and novel and rehas been provided embodying nal portions of the fuse body without the re quiring of soldering or special tools for renewing of the elements, and embodying features wherchy the fusible elen'lent is readily insertihle into the carrier body therefor, and one wherein the fragmentary portions of the blown fuse may he easily removed prior to application of the new fuse.

Various changes may be made to the specific form of the invention herein shown and described, .vithout departing from the spirit of the invention or the scope of the following claims.

I claim 1. In a renewable fuse, a tubular shell, a fusewire and a terminal connector for the fuse wire comprisiu a tubular u'letallic body providing a longitudinal passageway and having an externalannular flange formed intermediate its ends providing a plug portion for slidably fitting into the bore of the tubular shell and an externally threaded extension slotted thruout its length, said passageway thru the tubular metallic body having a bell shaped mouth at its inner end flaring into the circumferential surface of the plug portion, and retaining means threaded upon the extension for clamping the terminal portion of the fuse wire in engagement with the outer face of the annular flange.

2. In a renewable fuse, a tubular shell, a fuse wire, and a terminal connector for the fuse Wire comprising a metallic head including a plug portion for insertion into the bore of the tubular shell and an externally threaded shank portion arranged co-axially of the plug portion and having an annular flange formed at its inner end and providing an outwardly facing annular seat, said plug portion having a flaring pocket opening at its inner end and provided with a rounded bottom, and having a small passageway extending from the base of the rounded bottom in angular relation to the axis of the plug portion and opening upon the annular seat at one side of the threaded shank portion, and means threaded upon the shank portion for clamping the terminal portion of the fuse Wire extending thru thetubular shell in engagement with the outwardly facing seat.

3. A renewablefuse comprising a tubular holder of insulating material, a metallic head for the upper end of the holder having an external annular flange providing an outwardly facingannular seat, said head having a relative y large opening axially therethru provided with a flaring inner end, a metallic head for thelower end of the holder having an external annular flange providing an outwardly facing annular seat, said head having a flaring pocket opening at its inner end and provided with a rounded bottom and having a diagonal passageway extending from the base of the rounded bottom and opening at the annular seat, a fuse wire insertable thru the tubular body thru the head at either end thereof, and means for clamping the terminal portions of the fuse wire in engagement with the outwardly facing head of the head.

WALTER H. SCHRUPP.