US2243287A

US2243287A - Renewable fuse

Info

Publication number: US2243287A
Application number: US236842A
Authority: US
Inventors: Scheinbeim Hyman
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-10-25
Filing date: 1938-10-25
Publication date: 1941-05-27
Anticipated expiration: 1958-05-27

Description

May 27 1941 H. scHElNBElM 2,243,287

RENENABLE FUSE Filed 001;. 25, 1938 INVENTOR.

HYM N SCHEINBHM/ www mgm/f ATTORNEY.

Patented May 27, 1941 UNITED STATES PATENT OFFICE RENEWABLE FUSE Hyman Scheinbeim, New York, N. Y.

Application October 25, 1938, Serial No. 236,812

(Cl. 20D-131) 11 Claims.

This invention relates to renewable fuses for breaking an electrical circuit when the current reaches a predetermined value.

The present type of renewable fuse commercially used comprises a copper alloy cap having machined threads mounted on the two ends of a hard fibre casing similarly threaded. Since the two caps are inserted into a pair of metallic clips forming a fuse holder, the caps should be made of pure copper for maximum conductivity. Pure copper, however, is diflicult to machine because the copper drags Accordingly, a primary object `of my invention consists in providing ferrules or caps of pure copper that may \be used Without machining.

Fuses visibily indicating the actual capacity of the fuse link are not used commercially, although shown in the prior art. This results from improperly positioning the visible portion of the link when assembled.

A further object, therefore, is to provide a fuse in which the capacity of the fuse link will be indicated visibly and from the front position when the fuse is installed in the holder and which renders unnecessary the use of a. fuse link that is longer than the cartridge.

Other objects are to provide an inexpensive, renewable fuse of the cartridge or vknife-edge type, capable of being easily and quickly renewed with maximum safety, having maximum area of contact with the fuse supporting socket, with blocking means for preventing the vaporized metal of the fuse link from being ejected externally creating re hazards, and having means for preventing accidentally or otherwise, the insertion of more than one fuse link or an oversized link in the fuse chamber.

I accomplish these and other objects and obtain my new results, as will be apparent from the device described in the following description, particularly pointed out in the attached claims, and illustrated in the accompanying drawing, in which:

Fig. 1 is a plan view of my fuse.

Fig. 2 is an end view of the same.

Fig. 3 is a longitudinal sectional view.

Fig. 4 is a longitudinal sectional view of one end illustrating a modified blocking means for increasing the contacting end of my ferrules.

Fig. 5 is a plan view of my knife edge fuse.

Fig. 6 is an end view -of the same.

Fig. 7 is a longitudinal sectional view.

Fig. 8 is a sectional plan view of one end illustrating the knife edge supported therein.

In the drawing, reference numerals I8 and II designate the body of my cartridge which may be formed into two sections, each made of suitable electrically insulating and nre-resisting material. Each section contains a cavity I2 and I3 through which the fuse link I4 is suspended.

Ferrules I5 and I6 made of pure copper are slipped over the ends of sections I0 and II. The ferrules are provided with a suitable indentation Il and I 8, preferably rectangular, forming a seat for the fuse link I4 and enabling bolts I9 and 20 to be threaded therein, thus avoiding any projection beyond the cylindrical surface of the ferrules.

As shown in Fig. 3, each section, like section I0 illustrated, is provided with a passage-way 2| and 22 through which the fuse link I4 extends. An angular or V-shaped clip 23 is inserted at each

end having legs

24 and 25, the latter tting into ridge 26 of each end of sections I0 and II, completely blocking the passage-way 2l and 22, preventing the metallic vapors from escaping. The leg 24 of each clip 23 is apertured as at 2'I to permit bolts I9 and 20 to enter.

The legs 24 and -25 fit snugly into ridges 26, permitting only a xed thickness of fuse link to be inserted under the

legs

24 and 25. A greater thickness of fuse link, whether inserted accidentally or otherwise, will prevent the angular clips from being properly seated, blocking the insertion of the bolts.

The fuse link I4 extends beyond the clips 23, leaving exposed a small visible area upon which the fuse amperage is stamped. The indented ends Il and I8, of the ferrule I5 and I6, are apertured for entrance of the bolts I9 and 20, and a small recess 30 and 3| is moulded into the sections to permit

nuts

28 and 29 to be inserted therein for tightening the clips, link and ferrule together into a unitary assembly. The recess also serves to hold the bolt and nut and keep the ferrule assembly from slipping off the ends of the section.

A passage-

way

32 and 33 extends transversely through the ends of the sections I0 and II, axially aligned with the bolts to permit bolts of varying lengths to be accommodated.

The bottom surface of the ferrules are depressed as at 34 and 35 to assist in locking the ferrules to the sections.

In positioning the two identical and interchangeable sections Ill and II together, slots 36 and 3l may be moulded therein each section, into which suitable cement may be placed for securing the two sections together, and to avoid escape of the metallic vapors from the fuse link.

An additional leg extension 35 of the clip 23A thus forming a U-shape is shown in Fig. 4, in the event the fuse should be rotated in the supporting socket and an electrical contacting and supporting member is desired, extending transversely across the rectangular indentation of the ferrule.

ln Figs. 5, 6, 7 and 8 various Views of the same fuse are shown but provided with the familiar knife edge type of engaging means. This is identical in every way with the former type, except that the

nuts

28 and 29 are replaced by knife blade members di] and tI. The moulded sections H3A and IIB are changed to accommodate the knife blade members, recesses 3!! and 3l of the device illustrated in Fig. 3 being enlarged as shown in Figs. 7 and 8, to accommodate knife blades il@ and Iii provided with v cuts, 42, into which moulded Vs, 53, extend. The apertures 4d and 45 of the knife blades il and QI are threaded for engagement with bolts ISA and 20A.

The devices illustrated employ ferrules which are manufactured by taking tubular sections of pure copper and providing them with the rectangular indentations above referred to, or by forming the tubular lengths with continuous depressed sections. rThese are cut off into the desirable lengths, provided with bolt apertures and two bolts hold the entire assembly into position. The devices possess as much continuous surfaces in engagement with the supporting sockets as the former types to insure minimum electrical resistance. A possible variation of the tubular cutoi sections would be to use a at copper stamping of the saine metal, with the ends

adjacent dep essions

34 and 35. Such a variation would give the end ferrules a compressible feature not obtainable by the tubular cut-ofi sections, advantageously useful for holding the ferrules to the body member and for general economy.

The sections a e interchangeable as well as the two ferrules insuring a smaller investment in tools and a simpler and cheaper assembly charge. The fuse links can be easily removed and reinstated with just two boite being Unthreaded, and

are provided with visible ampere ratings on their ends.l

While the body is shown illustrated in two identical sections, it is obvious that one section may be employed having substantially the same fuse chamber and fuse link supporting shoulders.

I have thus described my invention, but I desire it understood that it is not coni-ined to the particular forms, shapes or uses shown and described,

the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of my invention, and, therefore, I claim broadly the right to ernploy all equivalent instrumentalities coming within the scope of the appended claims, and by means of which, objects of my invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.

What I claim and desire to secure by Letters Patent, is as follows:

1. A renewable fuse having a fuse link; a body section provided with a fuse chamber; two cylindrical and tubular end ferrules having indented sections on their cylindrical surfaces for engaging the ends of the fuse link; and means for electrically and mechanically connecting the fuse link to the f-errules.

Til

2. A renewable fuse having a fuse link; a body section provided with a fuse chamber; two cylindrical and tubular end ferrules having indented sections on their cylindrical surfaces for engaging the ends of the fuse link; and bolts for electrically connecting the ends of the fuse links to the ferrules.

3. A renewable fuse having a fuse link; a body section provided with a fuse chamber; two cylindrical and tubular end ferrules having indented sections cn their cylindrical surfaces for engaging the ends of the fuse link; the ends of the body shaped to receive the tubular end ferrules with the indented sections.

4. A renewable fuse having a fuse link; a body section provided with a fuse chamber and passageways leading therefrom to each end; two cylindrical and tubular end ferrules having indented sections on their cylindrical surfaces for engaging the ends of the fuse link; bolts for electrically connecting the ends of the fuse links to the ferrules; and V shaped metallic clips having an aperture for said bolts, for compressing said fuse links to said end ferrules and for blocking the passageways from the ends of the body section to the passageway.

5. A renewable fuse having a fuse link; a body section provided with a fuse chamber; two cylindrical and tubular end ferrules having indented sections on their cylindrical surfaces for engaging the ends of the fuse link; means for electrically and mechanically connecting the fuse link to the ferrules; and means for limiting the thickness of the fuse link insertable into the fuse chamber.

6. A renewable fuse having a fuse link; a body section provided with a fuse chamber; two cylindrical and tubular end ferrules having indented sections on their cylindrical surfaces for engaging the ends of the fuse link; and bolts for electrically connecting the ends of the fuse links to the ferrules; said fuse links having their fuse capacity indicated thereon adjacent the 10ngitudinal end of the fuse link and visible therefrom.

'7. A renewable fuse having a fuse link; a body formed of two symmetrical sections providing a central fuse chamber when assembled together; two cylindrical and tubular end ferrules holding said body sections together, having indented sections on their cylindrical surfaces for engaging the ends of the fus-e link; and means for electrically and mechanically connecting the fuse link to the ferrules.

8. A renewable fuse having a fuse link; a body formed of two symmetrical sections providing a central fuse chamber when assembled together, each symmetrical section provided with longitudinal slots for entrance of a cement for sealing the two body sections together along the longitudinal line of junction; two cylindrical and tubular end ferrules having indented sections on their cylindrical surfaces for engaging the ends of the fuse link; and means for electrically and mechanically connecting the fuse link to the ferrules.

9. A renewable fuse having a fuse link; a body section provided with a fuse chamber and passageways leading therefrom to each end; two cylindrical and tubular end ferrules having indented sections on their cylindrical surfaces for engaging the ends of the fuse link; bolts for electrically connecting the ends of the fuse links to the ferrules and U shaped metallic clips having an aperture for said bolts, for compressing 11. A renewable fuse having a fuse link; a body section provided with a fuse chamber; two cylindrical and tubular end ferrules having indented sections on their cylindrical surfaces for engaging the ends of the fuse link; a, pair of extending knife-like blades extending from the two opposite ends of said fuse having engaging means for interlocking with the body of said fuse; and means for electrically and mechanically con- 10 necting the fuse link to the ferrules.

HYMAN SCHEINBEIM.