US1878204A

US1878204A - Electric fuse

Info

Publication number: US1878204A
Application number: US281086A
Authority: US
Inventors: Alexander H Trumbull; George R Trumbull
Original assignee: BULLS EYE ELECTRIC Manufacturing Co
Current assignee: BULLS EYE ELECTRIC Manufacturing Co; BULLS-EYE ELECTRIC MANUFACTURING Co
Priority date: 1928-05-28
Filing date: 1928-05-28
Publication date: 1932-09-20
Anticipated expiration: 1949-09-20

Description

Sept. 20, 1932. A. H. TRUMBULL ET AL 158478304 ELECTRIC FUSE Filed May 28. 1928 Patented Sept. 20, 1932 UNITED STATES PATENT OFFICE ALEXANDER H. TEUMBULL, OF STBATFORD, CONNECTICUT, AND GEORGE E. TRUM- IBULL, OF MANCHESTER DEPOT, VERMONT, ASSIGNORS, BY DIRECT AND MESNE AS- SIGNMENTS, TO THE BULLS-EYE ELECTRIC MANUFACTURING COMPANY, OF TOR- RINGTON, CONNECTICUT, A CORPORATION OF CONNECTICUT ELECTRIC FUSE Application flied May 28, 1928. Serial No. 281,086.

The present invention relates to electric fuses for use in electric installations, more particularly to fuse plugs, and has for one of its objects to provide a fuse plug of novel and improved construction whereb the same is simplified and the visibility of t e interior of the plug is considerably enhanced and the amperage rating easily read.

A further object is to so construct the plug that, if desired, parts thereof may be renewed when worn and the insulation of the conductive parts may be improved.

Further objects and advantages will appear from the following Specification and will be incorporated in the appended claims.

In the drawing which constitutes a part of the specification,

Fig. 1 is a longitudinal section through a plug made in accordance with the principles of my invention showing the arrangement of the various parts relative to each other;

Fig. 2 is a plan view looking down on the top of the plug;

Fig. 3 is a bottom plan view of the plug;

Fig. 4 is a View showing the base of the plug with the conductive elements imbedded therein, and the connection of the fusible strip to the conductors; all other parts of the plug being omitted for clarity of illustration;

Fig. 5 shows a modified form of the arrangement of the conductor in the base, the fusible element being integral with the conductors;

Figs. 6, 7 and 8 illustrate still further methods of connecting the fusible strip to the conductors.

The plug as illustrated in Figs. 1, 2, 3 and 4 comprises a chambered body member 10 molded or otherwise formed of insulating material of a translucent or transparent nature, preferably of clear glass and provided at its top with a peripheral flange 11 which may be milled as at 12 over portions of the edge thereof and at diametrically opposite sides of the cap in order to facilitate turning of the plug. A lens 13 may be formed centrally of the top of the member and in alignment with the chamber 14 formed in the body. Extending downwardly from the flange 11 are the tubular side Walls 15 defining the chamber 14. If

the plug is to be of the screw type, the side walls 15 will be exteriorly threaded as shown at 16 to accommodate the thread 17 of a shell 18 for connecting the said parts together. If other types of plugs are used such as those employing bayonet slots and the like, it is obvious that the walls 15 may be shaped as required.

The shell 18 is of conductive material as copper or brass and is provided at its lower end with an inturned circumferential flange 19 which overlaps the flanged edge, to be hereinafter described, of a circular disclike base member 20 to hold it in place against the lower edge of the wall 15, the said base forming a closure for the chamber 14. The base 20 may be provided with ventilating openings or notches 20a to permit the escape of gases, etc.

The base member 20 is formed of insulating material as bakelite or the like that is suitable for the imbedding therein of the

conductor members

21 and 22. The base member may be centrally domed outwardly as at 23 providing the circumferential flange 23a referred to above provided on its upper face with upstanding lugs 24, portions 24a of which are adapted to fit snugly in recesses 24?) formed in the wall 15 of the chambered member 10 for centering the base relative to said member and to prevent relative rotation of these parts when the shell 18 is in place.

Conductors

21 and 22 may be L-shaped and extend through the base at opposite sides thereof, the horizontal portion of the conductor 21 lying partly in a recess 25 in the dome 23 and extending laterally therefrom to contact with the flange 19 of the shell 18 and lie between said flange and the flange 23a of said base 20. The horizontal portion of the conductor 22 extends to a point centrally of the dome and constitutes the contact for one of the contacts of the circuit.

The

contacts

21 and 22 are connected within the chamber 14 by a fusible strip 26 of any weil known character which may be se-- cured to

conductors

21 and 22 in some suitable way preferably by rivets 2'2." or may be secured thereto in the manner shown in. Figs. 6, 7 and 8, in which case the fusible strip is apertured as at 28 to receive therethrough lugs 29 on the ends of the conductors, these lugs being bent over or peened down to secure the parts together or they may be split as shown at 29a in Fig. 7 and bent over to hold the strip in place. In the method of securing the fusible strip to the conductors shown in Fig. 8, the conductors are provided .with outwardly flared ends 35 which are extended through the apertures 28 and the resilence of the

conductors

21 and 22 is depended upon to hold the parts together. Contact between conductor 21 and shell 18 is assured by a drop of solder 30 placed thereon so as to bridge the two members.

It will be noted that the drop of solder lies partly in the recess 25 thereby assisting in preventing turning action of the shell relative to the base. At the same time the lugs 24, projecting into recesses 24a prevent relative rotation of the base and the wall 15. It will be seen therefore that the single drop of solder placed as stated above will prevent the removal of the shell an'd'base and consequently will prevent access to the interior of the plug. This drop of solder may be readily scraped off when it is desired to remove the shell from the chambered member for any purpose.

From the foregoing description it will appear that we have provided a fuse plug to be used in electric circuits which is simple of construction and cheap of manufacture, in which the insulation is highly efiicient and in which when the fusible parts are burnt out, may be readily disassembled andthe'burnt out parts renewed. We have also provided aflug, the chambered part of which is molde of glass or other transparent material andj provi ed with a lens in alignment with the chamber so that the condition of the fusible strip and other parts within the interior of the chamber may be readily observed, the parts being enlarged and rendered therefore more visible. We have located the am rage notation or rating as at B on the usible strip so that while comparativel small, it ma be rea 'lyobserved through the lens an correctly read. We have simplified and chea ned the cost of manufacture, while providing a device of superior qualities and greater usefulness.

Having described our invention what we claim is:

1. A fuse plug for use in electric circuits, comprising a chambered body having a chamber defining exteriorally threaded tubular wall, an insulating base member, contact members embedded therein, a shell threaded to said wall, one of said contact members contacting with said shell beneath said base, both contacts extending into the chamber and a highly fusible member connecting said contacts within the chamber, 68 said wall having recesses therein, said base having diametrically op osed lugs fitting said recesses, and a drop of solder connecting said shell with the contacting contact member and preventing rotation of the shell.

2. A fuse plug comprising a body having an exteriorally threaded tubular wall defining a chamber, a base member constituting a closure for said chamber, conductors extending therefrom into said chamber and fusibly connected therein, said wall having opposed recesses, lugs rising above the base and received in said recesses to prevent relative rotation of the base, a shell threaded to the wall and having a flange underlying the edge oft'he base and electrically connected with one of the conductors, a drop of solder conneoting the flange of shell with said last named conductor and holding the shell fixed relatively to said body.

3. A fuse plug comprising a one-piece molded body including a hollow tubular portion defining a chamber, a base constituting a closure for said chamber, contact members arranged within the chamber and having angularly disposed extremities located beneath the base, a fusible member arranged within the chamber and connecting the contact members, a shell threaded on said tubu lar portion of the body and having an inwardly directed flange supporting said base, the offset extremity of one of said contact members lying between the base and said flange and electrically connected with the latter, and a drop of solder connecting the said flange and contact member and holding the shell fixed relatively to said body.

4. A fuse plug comprising a one-piece body including a hollow tubular portion havfiipg a chamber and spaced recesses and a magnifying lens portion integral with the bo y and disposed in a line with said chamber, a peripheral flange integrally formed on said body and having a hand gripping portion around its edge, an insulating base constituting a' closure for said chamber, upstanding lugs on said base adapted to cooperate with the recesses in the tubular portion for centering the base, contact members supported by sa1d base, each of said contacts extending below the base and one of 11 said contacts being formed with an offset foot portion, a fusible member arranged within the chamber and connecting the contact members, a shell secured on said tubular portion and having an inwardly directed flange adapted to engage the offset portion of the contact and means for making said engagement permanent whereby said shell is fixedly held relative to the body portion.

5. A fuse plug comprising a one-piece glass 1 body having a magnif ing lens portion at its outer end and a tubu ar portion extending therefrom, saidtubular portion having lateral projections for interlocking with a screw shell, an insulating base -having prbjecting 13ostem and provided with indicating characters visible through the lens portion, a screw shell interlocked -.with the lateral projections on the tubular portion and having a flange embracing the edge of the base, and electrical conducting means connecting the fuse strip to the screw shell,said means including solder and preventing rotation of the screw shell with respect to thebase.

6. A fuse plug comprising a one-piece glass body closed at its outer end and having a hand grip portion and having a rearwardly projecting tubular portion provided with screw threads, an insulating base having a projection and the tubular portion having a portion coacting with said projection to prevent rotation of the base with respect to the body, a. center contact member having a stem pro ecting through the base into the tubular portion, a side contact having a foot at the edge of the base and a stem projecting into said tubular portion, a fuse strip connecting the inner ends of said stems, a screw shell threaded on the tubular portion and having a flange embracing the edge of said base and solder connecting a part of the screw shell to the foot of the side contact.

7. A fuse plug comprising a one-pieceglass body having a tubular portion with an inner chamber and having threads on the exterior at the inner end and provided with a laterally projecting flange around the outer end constituting ahand grip and having an outwardly projecting magnifying lens portion in line with the inner chamber, an insulating base closing the end of the chamber opposite the lens portion, said base and the tubular portion of the body'having interlocking portions preventing relative rotation of the base and body, a screw shell mounted upon the threads of the body and having a flange overlying the edge of the base to hold the parts together, a center contact carried by the base, a conducting strip having one end interlocked with the base and secured to a part of the screw shell so as to prevent relative rotation of the screw shell and base and a fuse member electrically connected to the center contact and to the screw shell and visible through the lens portion of the body.

In testimony whereof we aflix our signatures.

ALEXANDER H. TRUMBULL. GEORGE RTRUMBULL.