US1344296A - Plug-fuse - Google Patents

Description

A L. EUSTICE.

PLUG FUSE.

APPLICATION FILED Aue.23, 1918.

1,344,296; Patented June 22, 1920.

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T 0 all whom it may concern.

UNITED STATES PATENT orrlcs.

ALFRED L. EUSTICE, OF CHICAGO, ILLINOIS.

PLUG-FUSE.

Specification of Letters Patent. Pate t d J 22 1920.

Application filed August 23, 1918. Serial No. 251,091.

Be it known that I, ALFRED Eusrron, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Plug- Fuses, of which the following is a specification.

This invention relates to plug fuses.

One of the objects is to simplify and im prove the general construction of plug fuses.

' Another object is to construct a plug fuse in a novel manner whereby it can; be observed readily whether or not the fusible element has become ineffective. 4

Another. object is to provide a novel plug fuse adapted to meet the various requirements for successful commercial usage.

These and other ob]ects are accomplished by means of the plug fuse disclosed on the accompanying sheet of drawings, in which- Figure 1 is a side elevation of my plug fuse F i g. 2 is an end'elevation of one end of the plug fuse;

Fig. 3 is an end elevation of the opposite end of the plug fuse; and

Figs. 4 and 5 are longitudinal sectional views of the same plug fuse on an enlarged scale taken at right angles with respect to each other.

The various novel features of my invention will be apparent from the following description and drawings and will be particularly pointed out in the appended claims.

Referring to the figures of the drawings,

it will be noted that I have provided a plug fuse including a hollow base 10 of'insulatmg material provided with a gnarled head 11 whereby the plug fuse may be readily screwed into a socket. The barrel portion of this base 10 is provided with an external threaded portion 12 and with a longitudinally extending groove 13 which interrupts the threads. A disk 14 of insulating material closes one end of the hollow base 10 and is provided with two apertures 15 through which one end portion of a fusible element 16 is threaded for forming one terminal, it being understood that this end of the fusible element is doubled back upon itself on the inside of the disk 14 for secur- I ing the former to the latter. The intermediate portion of the fusible element 16 extends through the hollow barrel portion of the plug 10 and near the head of this base is provided with a drop-out link 17 formed by two narrow neck portions 18. Beyond this drop-out link portion, the'fusible element extends toward the disk 14.- and passes to the outside of the fuse base and occupies the groove 13. A threaded shell 17' of conducting material is threaded over the threaded barrel portion of the base 10 and has a flange 18 which holds the disk 14 intermediate said flange 18 and one end of the base 10. To make a good electrical contact between the shell terminal 17 and its cooperating end of the fusible member, a drop of solder may be used. The inter mediate looped portion of the fusible element 16 is supported by an insulating member 19, preferably of mica, which normally 1s supported in oppositely arran ed grooves 20 formed on the inside of the barrel portion of the base 10. This insulating member 19 also rests in a groove 21 on the inside of the disk 14 for preventing the passage of a destructive are between oppositely arranged portions of the fusible element.

In order that the condition of the fusible element may be readily observed, I have provided the head end of the plu with a window 22, which preferably is 0 mica, or any other suitable transparent material, said window being held between oppositely arranged flanges 23 formed integrally with a metal windowframe 24, the outer end of which, after being inserted into the opening 25 of the base, is spun over at 26 to form a flange to prevent displacement of the frame, cooperatingin this respect with one of the flanges 23. It will be appreciated that the flanges 23 may be formed while assembling the window frame in the base or may be formed previously thereto. If the fusible element is rendered ineffective for any reason, the same will be served through the window the fuse may be repaired.

' By means of this arrangement a plug fuse readily ob- 22, whereupon simple in construction and adapted for commercial usage is provided,

It is my intention to cover all modificathrough the apertured disk to form one terminal and having another portion extending along said groove, a conducting-terminal shell fitting over said base for securing the disk thereto and being electrically connected to the fusible element, and a supporting member for an intermediate portion of the fusible member retained by'the grooves on the inside of said base.

2. A plug fuse including, in combination, a hollow base, a fusible member mounted therein, a flanged window frame mounted wholly within one end of the base, and a transparent member mounted in said frame between its flanges whereby the transparent member is securely held and whereby the condition of the fusible element may be observed.

3. A plug fuse including, in combination, a hollow base, a fusible member mounted therein, a flanged window frame mounted in one end of the base, and a transparent member mounted in said frame between its flanges whereby the transparent member is of the fuse, a fusible element having one portion extending through the apertured disk to form one terminal and having another portion extending along said groove, said fusible element including a drop-out portion, a conducting terminal shell fitting over said base for securing the disk thereto and being electrically connected to the fusible member, and a transparent member closing the other end of the base and being arranged adjacent a drop-out portion of the fusible element whereby the condition of the fusible element may be observed.

Signed at Chicago, Illinois, this 17th day of August, 1918.

ALFRED L. EUSTICE.

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