US1478109A - Cartridge fuse - Google Patents

Description

Dec. 28, 1923. 1,478,109

E. H. ELLISON CARTRIDGE FUSE Filed April 27 1920 Patented Dec. 18, 1923.

v 1,478,109 PATENT OFFICE.

EDWARD H. ELLISON, OF JAIIBTOWN, NEW YORK, ASSIGNOB TO KONABCH REFILL- AJBLE FUSE 00., OF JAIESTOWN, NEW YORK, A CORPORATION 01 NEW YORK.

CARTRIDGE FUSE.

Applicatlon flled April 27, 1880. Serial Io. 876,982.

To all whom itma l concern:

Be it known that I, EDWARD H. ELLISON, a citizen of the United States, residing at Jamestown, in the county of Chautauqua, State of New York, have invented certain new and useful Improvements in Cartridge Fuses, of which the followin is a description, reference being had to the accompanying drawing and to the figures of reference marked thereon.

Prior to my invention,'fuses of the ferrule or cartridge type have been formed wherein the ends of the fusible link extend through slots in end washers and are clamped against said washers by caps which are threaded onto the casing forming the body portion of the fuse, and said end caps are formed with openings for exposing to view a character indicating the capacity of the fuse. No means, however, was provided for locating this capacity identifying character relative to the opening of the end cap, and, as a consequence, great care is necessary in the assembling of the parts in order to position the character so that it may be within the limits of the opening in the end )ne of the objects of the present invention is to provide a ferrule or cartridge type of fuse of the above character with means whereby, when said fusible link is assembled, the overlap of the bent-over portion will always be to a predetermined amount, thus insuring that the character indicating the capacity of the fuse will be correctly placed relative to the opening in the end cap.

A further object of the invention is to provide a ferrule or cartridge type of fuse of the above character wherein the end cap is provided interiorly with a thread adapted to engage an exterior thread on a sleeve attached to the casing or body portion, and wherein said end cap is provided with an integral skirt extending down over said sleeve so as to form a uniform cylindrical contact surface of sufiicient length for engagement with the supporting clips for the fuse without restricting the length of the casing of insulating material.

A further object of this invention resides in providing a cartridge fuse of the above character with a fusible link, the ends of which are composed of a metal of a relatively high melting point and provided obvious and will in with an intermediate portion or portions of flames as they pass outwardly through the apertures in the end caps.

- These .and other objects will in part be art be hereinafter more fully disclosed in t e accompanying draw- 1ngs which show by way of illustration one embodiment of the present invention.

Referring more particularly to the accompanymg drawings Figure 1 is a sectional side viewof the improved fuse,

Fig. 2 is a detailed group perspective of the component part of the link,

Fig. 3 is an end view of the link fold, the caslng being shown in section, and

Fig. 4 is a view of the link.

The invention in one of its broad aspects isdirected to a fuse of the ferrule or cartridge type having a casing of insulating material, preferably tubular or cylindrical, to which are secured end caps, and associated with each end cap is a clamping washer having a slot through which the end of the fusible link extends, the end of the link being bent over onto the washer and clamped thereagainst by the end ca and the end cap having an opening ormed therein whereby a character impressed in the end of the link and indicating the capacity of the fuse may be viewed. The fusible link is provided with means which determine the extent to which the end of the link is bent down onto the washer. In the preferred form of the invention, said link is formed with shoulders which engage against the inner face of the washer adjacent the ends of the slot, and this determines the extent to which'the end of the link projects beyond the outer face of the washer and, as a consequence, the extent to which the end of the link is to be bent down onto the washer. This insures that the indentifying character impressed in the end of the link and indicating the capacity of the fuse will be brought into register with the opening of the end cap. Then agaln, the invention in another of its broad aspects is directed to the construction of the end cap which is interiorly threaded so as to make engagement with the metal sleeve attached to the casing of insulating ma terial. This cap is formed with a skirt which extends down over the sleeve, and thus the cap is formed with a contact surface of the proper length for engaging the clips in which the fuse is placed and, at the same time, the body of insulating material forming the casing extends substantially from one end cap to "the other. In other words, the sleeve which is connected to the casing and to the end cap extends almost wholly within the end cap.

Still another broad phase of the invention resides in the combination of a link of metal of relatively high melting point and having at least one intermediate portion of metal fusing at relatively low melting point with an inclosing insulation tube provided at each end with slotted washers through which the link ends e):- tend, the same being held in position folded over the outer faces of these washers of the end caps, closing the end of the casing and making electrical connection with the link ends.

Referring particularly to the drawings, the invention includes an inclosing casing in the form of a tube of insulation 1 threaded internally at each end to receive therein the metal ferrules 2 which project slightly beyond the end of the casing where they are enlarged radially as at 3 to provide circumferential threaded faces flush with the outer circumference of the tube 1. Preferably the casing and ferrules are held in such threaded relation by means of metal rivets 4.

Arranged at each end of the casing and abutting the end faces of these metal ferrules are washers 6 and 7 slotted in any desired manner, but preferably as shown clearly at 8 in Figure 2, to provide a passage therethrough for the ends 9 and 10 of the fusible link 1. These link ends which pass through the slots in the washers are folded over the outer faces of the washers and make electrical connection with the end caps 11 and 12. These caps are provided with internal threads 13 engaging the metal ferrules 2 and extensions or skirts 15 and 16 of the same outer diameter as the caps, projecting inwardly over the fiber ends of the casing 1 substantially flush with the inwardly projecting ends of the inner metal ferrules 2, whereby an extended surface is provided for affording good electrical contact with the usual clip.

In order to insure that the amperage mark which is stamped or otherwise marked on the outer face of the folded over end of the link may always register with suitable apertures 18 and 19 in the end or outer faces of the end caps 11 the link ends are provided net/arcs with means for assuring that a uniform length of fuse will project through the washer slots 8 and be folded over the outer face of the washer. One form of said means consists in providing the link ends with shoulders 20 adapted to engage the inner faces of these washers for limiting such projection. Tn other words, when the fuse is inserted in the slot in the washer and the fuse pulled, so that the shoulder 20 bears against the inner face of the Washer, a predetermined length will always be turned down over the end of the washer, bringing the number imprinted upon the end of the washer to indicate the capacity of the fuse, directly into register with the opening or aperture in the cap My improved fuse link has special application to a fuse of the above construction due to the fact that when the link metal volatilizes the gases and flames rush endwise and seek to escape through the openings 18 and 19 in the cap ends. If the link be of the usual type, the immense heat created will tend to volatilizeall the link metal in the path of the escaping gases so that the link terminals will be fused to the end washers 6 and 7. By making my link 5 of a metal f relatively high melting point and providing the same intermediate its ends with a fusible portion or portions of relatively low melting point, the fusing is confined to the intermediate portion of the link and the terminal connections preserved.

This improved fuse link which is the subject of a co-pending application i. e. Serial Number 376,933, filed by applicant April 27, 1920, filed concurrently with this application, is composed of copper intermediate the ends of which is located a melting zone made of a series of zines and copper sections connected together and to the copper ends of the link proper by interfolding the metal of the successive portions. Preferably the sections adjoining the copper link ends are composed of zinc, while arranged between these two zinc sections is a single copper section; As a result of this arrangement, the zinc sections will volatilize first and the intermediate copper section will drop out thereby preventing arcing. Furthermore, these adjacent portions being of copper, which has a higher melting point will not be fused.

Considering the fuse as a whole, it is evident that the. end ferrules provide a firm metallic end face for the abutting washers so that a good electrical connection may be had between the end caps and the link terminals. As heretofore made, these end caps were generally threaded directly upon the insulation casing itself, which threads after considerable use, were apt to Wear, in the present construction, by reason of the metallic threads on the outer surfaces of theend ferrules, a most durable threaded connection with the end caps is provided. It will also be apparent that by arranging ferrules within the bore of the casing, when the latter shrinks, it tends to tighten the joint be tween the casin and the ferrule. Furthermore, by threading the metal end caps over the casing end ferrules and providing such caps with skirts extending over the inner ends of the insulation tube to parts substantially flush with the inner ends of said ferrules, an extended contact surface for the clips is provided substantially equal to the full length of these metal ferrules.

It will be obvious that minor changes in the details of construction and arrangement of parts may be made without departin from the spirit of the invention, as set fort in the appended claim.

Having thus described the invention, what I claim as new and desire to secure by, Letters-Patent, is

A cartridge fuse comprising an enclosing tube of insulating material, a fuse link therein having end portions of less width than the main body of the link to form shoulders vspaced from each end-of the link, a washer abutting and closing each end of said casing and provided with a closed slot of width substantially equal to the width of the narrow end of the link, said fusible link extending through said tube and said shoulders abutting the washers, the narrower ends of the link extending through the slots in the washers, and the end of said link being folded over the outer faces of the washers and provided with a fuse amperage mark thereon, and apertured metal caps closing the ends of said casin and forming an electrical connection with t e folded ends of said link, the aperture of said caps registerin with the indicating marks on said ink en In testimony whereof I afiix my signature.

EDWARD H. ELLISON.

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