US1436919A - Renewable fuse - Google Patents

Description

W. U, SMHH.

RENEWABLE FUSE.

APPLICATWN man MAY28.1921.

Patented Nov. 28, 1922.

a citizen of the United States,

fuse link;

non-conducting material.

Patented Nov. 28, 1922.

IUNITED STATES PATENT OFFICE.

WALTER 0. SMITH, OF NEW BEDFORD, MASSACHUSETTS.

RENEWABLE FUSE.

Application filed May 28, 1921. Serial No. 473,248.

' To all whom it may concern:

Be it'known thatI, WALTER 0. SMITH, residing at New Bedford, in the county of Bristol and State of Massachusetts, have invented certain new and useful Improvements in Re newable Fuses, of which the following is a specification.

This invention is an improved renewable fuse and has for its object the provision of means whereby the fuse may be readily renewed when occasion demands and in which a good electrical contact will be effected between'the fuse link terminals and the fuse terminals. -A further object of the invention' is to provide a simple and inexpensive construction'by which access to the interior of the barrel will be permitted when necessary and accumulated soot and other parti'clesmay be removed. The invention also seeks to provide improved means for holdingthe ends of the fuse link against accidental or premature separation from the fuse terminals.

The invention is fully illustrated in the accompanying drawings, in which F igure 1 is a longitudinal section of a fuse illustrating one embodiment of the invention Fig. 2 is a transverse 2-2 of Fig. 1; Fig. 3 is a detail perspective view of the binder; 7 Fig. 4 is a detail perspective view of the section on the line Fig. 5 is a detail perspective view of the contact plate or disc.

Fig. 6 is a detail section showing another formof the invention;

" In carrying out my present invention, I employ a barrel 10 which is preferably of fiber but,of course, may be of any other Upon each end of the barrel, I secure an internally threaded ferrule 11 which is of some good conductor,

preferably copper or brass, the ferrules being threaded onto the ends of the barrel and then indented at one or more points, as indicated at 12, so that the threaded inner end of the ferrule will be partly mutilated and a portion of the material of the ferrule embedded in the barrel. The ferrule will thus be permanently attached to the barrel, as will be readily understood. I also employ a contact member 13 which is preferably a circular plate or disc having threads or rounded so as to engage the longitudinal in its peripheral edge whereby it may be enat the two ends of the barrel and the description herein given is ap licable equally to either end of the fuse. he tact plate is turned home in against the end Fig. 1, and it slot 14 having the end of the The outer surface of the disc or plate is smooth, as shown at 16, so that the end of the fuse link may be bent against the same and form a perfect contact therewith The fuse link is preferably a ribbon l7 weakened midway its ends, as shown at 18, and having its extremities bent in opposite directions, as shown at 19, when it is secured in place within the fuse. The edges or corners'20 of the slot 14 in the contact plate. are beveled avoid cutting the fuse link at said points and to facilitate the insertion of the contact plate and also its removal, when removal is desired, I provide the ferrule of the barrel, as shown in is provided with a diametric flat walls 15 through which disc or confuse linkmay be inserted. y

notches 21 at the ends of the'slot which may 1 be engaged by a screw driver or other turning tool in an obvious manner. To secure the ends of the fuse link in and against the contact plates, I employ a binder 22 which may conveniently be stamped from sheet metal. This binder, as shown in Fig. 3, comprises a base portion 23 and a diametric rib or'projection 24 extending across the base portion and having its sides normally converging .toward its crown whereby I it is adapted to perform the functions of a wedge when inserted in the slot 14 of a contact member 13. It will be readily noted that the projection or rib 24 is struck up from the base portion 23 of the binder and will. 3

the edge .of the binder and the'internal As shown in Fig. 1,

threads of the ferrule. the sides of. the arched projection or rib 2% portion of the fuse link and have a wedging or clamping action thereon so that it is held to the side wall of the slot 14 and the base portion of the diameter binder bears against the outturned extremity of the fuse link and holds it in intimate contact with the outer fiat surface 16 of the contact member 13. 7 To retain the binder in operative position, I employ a follower in the form of a closure plug 25 which is threaded into the ferrule and turned home against the base portion 5230f the binder,

as clearly shown in Fig. 1, so that the binder will be positively and effectually clamped between the plug and the contact member. As shown in Fig. 1, the closure plug or follower "is provided with a central notch 26 which may be utilized as a means of engagement with a turning tool so as to turn the plug home. Instead of the central notch, the plug may be provided with eccentric notches or recesses to be engaged by aspanner.

In assemblmg the fuse, the ferrules are first threaded onto the ends of the barrel and the indentations formed therein so that the ferrules become a permanent part of the device. The contact members 13am then turned home in the ferrules so to abut-the ends of'the barrel and the parts ar so proportioned that, when the two contact members are fully turned home, the slots 14 therein will register. The fuse link is then inserted through the ferrule at one end of the barrel and through the slot in the contact plate within said ferrule, the feeding of the link being continued until the ad vance end thereof passes through the slot 14 at the opposite end of the barrel. The eX- tremity of the link at one end is then bent against the outer face of the adjacent contact member and a binder is engaged in the slot 14- or said platc'and against the outer surface of said plate thereby clamping the end of the link, as shown in Fig. 1. The

follower or closure plug is then turned home against the base portion of the binder so that the binder will positively clamp the terminal of the fuse link into tight electrical connection with the contact member and the binder will be clamped between the latter and the follower. The operation is then re peated at the opposite end of the fuse which will then be complete and may be used in the usual manner.

The fuse shown and described is intended to be engaged and held by spring fingers or clamping members which form contacts in the electric conductor. If it be desired to apply the invention to fuses having knife blade contacts, the knife blade 27 is formed on or secured to the binder so as to project therefrom in alinement with the arch of the same and a collar 28 is then threaded into the ferrule so that its inner end will bear upon the edge of the binder, which bears,

against the end of the fuse link and forces it into tight electrical connection with the contact plate, said collar being provided with a flange 29 at its outer end to facilitate its manipulation and abut the outer end of the ferrule so as to limit the turning move ment of the collar.

It will be readily seen that I have provided a very inexpensive fuse which will be found. highly efficient in use. The engagement of the end of the fiber barrel against the contact plate will be strong enough to frictionally resist turning of the contactplate so that the fuse cannot be twisted when the outer plug is being tightened. This holding of the fuse link against twisting and consequent accidental rupture does not prevent a perfect contact between the end of the link and the contact member being effected inasmuch as the binder is so constructed that its nose or arched ribf projection willfit snugly within the flat-sided slot of the contact plate and its leaves will extend over the outer bent portion of the fuse link and hold it firmly against the contact member and relative movement of the binder will be positively prevented. by the engagement of its nose within the contact member.

When a fuse blows, it is very common for particles of the metal to cling to the inside of the barrel and frequent blowing causes soot to accumulate within the barrel. lVith my present construction access may be had to the interior of the barrel to remove all such accumulations and when a new fuse link has been inserted the fuse will be in perfect condition. 7

Having thus described the invention, what is claimed as new is:

A fuse comprising a barrel, a ferrule fast on the end of the barrel,. a contact disc threaded into the ferrule and abutting the end of the barrel, said disc having a fiatsided. diametric slot, a fuse link extending through the barrel and having its terminal projecting through the slot in the adjacent contact disc, a binder disposed loosely within the ferrule at the outer sideiof the contact disc and having a flat-sided nose engaging within the slot of the, contact disc and basal leaves bearing against the outer face of the contact disc, the end ofthe fuse link being held against one wall of said slot by the noseof the binder and against the outer face of the disc by a basal leaf of the binder, and means within the outer end of the ferrule to clamp the binder against the outer face of the contact disc and the end of the fuse link.

In testimony whereof I affix my signature.

I wALTnno. SMITH. 1.8;

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