US2071934A - Multiple fuse plug - Google Patents

Description

Feb. 23, 1937. B. I. mess ET AL MULTIPLE FUSE PLUG Filed July 7, 1932 m M M m Patented eb. 23, 1937 I UNITED STATES MULTIPLE FUSE rLUG Benjamin L Moss and Francis J. LandgraffChicago, Ill., assignors to Leopold Moss, Chicago,

Application July 7, 1932, Serial No. 621,198

Claims.

Our invention relates to fuse plugs and particularly to multiple fuse plugs. Fuse plugs of a multiple type contain a plurality of fuse elements with means for successively connecting 3 the fuse elements into the circuit so that when one is burned out another one will be available to take its place without inserting a new plug. Suggestions have been made for providing visible means for indicating the condition of the differlO ent fuse elements in the plug. Plugs having such visible means suggested in the past have not been satisfactory for several reasons, but principally because of the fact that the indicating means has not worked out satisfactorily.

The principal object of our invention is the provision of an improved multiple fuse plug.

Another object is the provision of a multiple fuse plug having improved means for indicating the condition of the separate fuse elements.

A further'object is to confine discoloration of a translucent member to the region immediately adjacent the fuse element which is burned out.

Another object is the provision of a greatly simplified multiple fuse element which can be produced more cheaply and operate more satisfactorily than other multiple fuse elements heretofore designed.

Other objects and features of the invention will be apparent from a consideration of the following detailed description taken with the accom panying drawing, wherein Fig. l is an enlarged vertical sectional view;

Fig. 2 is an irregular plan sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a sectional view taken along the line 3--3 of Fig. 2; I

Fig. 4 is a plan view of the plug:

Fig. 5 is a bottom plan view of one of the members;

Figs 6 to 8, inclusive, are perspective views of some of the parts;

Fig. 9 is a plan view showing the fuse elements before assembly in the plug; and

Fig. ii) is a plan view showing a modified form.

In general, we provide an outer housing or fuse body having a pair of contacts, within which is rotatably supported a fuse element carrying plug. The plughas an extension which with the plug proper forms a plurality of closed apertures or chambers through which the fuse elements extend. A translucent member turns with the plug and serves to close off the apertures in the plug member thus confining the fuse elements so that the heat and gases generated when a fuse element is blown out will be confined to the closed aperture or chamber, and the discoloration of the translucent element will also be confined to the space adjacent such chamber.

Referring now to the drawing, the numeral it) indicates a hollow body member having the usual 5 shell contact ii and center contact i2. Within the hollow body we provide a rotatable plug including a plug body i3 and a plug extension H.

The plug body shown in detail in Fig. 7 is provided with segments i6 forming between them 10 fuse element containing channels l1 which extend down at Ila on the sides of the plug body. The fuse elements l8 indicated in Fig. 9 preferably comprise a plurality of strips of suitable material crossed to form a spider, it being under- 15 stood, of course, that a suitable stamping having the same shape as the assembled fuse elements of Fig. 9 may be utilized.

The fuse elements are centered and partially supported by a contact extension i9, which ex- 20 tends through apertures 2i in the fuse elements and through an axial port or opening 22 in the housing. The fuse elements are bent around and. down along the sides of the plug body into the channels in and a retaining washer 23 25 functions to support the fuse elements in position. This retaining washer has internal extensions 24 which by extending into the channels lid of theplug body definitely support the lower ends of the fuse elements and cause the retaining 30 washer to rotate with the plug body.

The retaining washer is held in position due to the fact that it extends outwardly beyond the main portion of the plug body, its periphery coinciding with an annular flange l6a on the plug 35 body, and the washer resting upon a shoulder 26 formed in the interior of the'housing, or body member.

The plug extension is provided with an annular projection 21 which engages an annular shoulder 28 on the housing. It is also provided with a plurality of squared projections 29 which extend down into the channels I! on the plug so as to provide a substantially closed chamber immediately above the narrowed portion l8a of 45 the fuse member which is the portion that blows or burns out. Apertures 3i running entirely through the plug extension put the chamber in communication with a translucent member 32, preferably a mica disc. An aperture 35 in the 50 center of the member 32 accommodates thumbpiece 31. This translucent member, therefore, serves as one wall of the chamber and substantially completely houses the individual fuse ele-' ments.

The translucent member (Fig. 6) is provided with a plurality of notches 33 into which pro-- jections 34 on the top of the plug extension engage serving to turn the translucent member with the plug extension. Since the squared extensions 29 engaging in the channels II serve to turn the plug body, it is clear that the translucent member is always in the same relative position with respect to the plug body, and also with respect to the fuse elements. Should a fuse burn or blow out, the portion of the translucent member forming as it were one wall of the chamber in which the fuse member is housed, will be discolored but the remaining portion of the translucent member will be maintained in its original condition.

Any suitable means may be employed for holding the housing and plug in assembled relation and permitting a visual inspection of the translucent member. Preferably we employ a metal cap 36 apertured to pass a thumb piece 31 for turning the plug and having an aperture 38 for inspecting the translucent member and fuse beneath the same. The cap is substantially cup shaped and is clinched around the shoulder 28 on the body member or housing. This completes the assembly.

For connecting the fuse elements into the circuit, including the contacts H and I 2, we provide means including extending the contact extensions l9 into the hollow shaft of the contact member l2. This serves to connect all of the fuse elements at their center with the center fuse contact. For forming the other contact, a

1 spring contact member 39 is provided having a portion extending through the body Ill and wedged between the shell I I and body. Solder M or other suitable means is, of course, utilized to provide a firm electrical contact.

As shown in Fig. 2, this spring member is shaped to extend into the channels Fla and contact with the end of the fuse element contained in the channel. The plug body 42 between the channels is shaped so that when the plug is rotated 45 in the direction indicated by the arrow, the spring will ride up easily on the portion 42 as on a cam and will drop off sharply into the next channel Ila. This serves two useful purposes. It produces a clicking sound which audibly indicates to the user of the plug that he has established a second contact. It also has the advantage of making a firm and quick contact which is especially advantageous should the user by accident leave the current turned on in the plug circuit.

The functions of our plug and the manner in which it is manufactured and used appear clear from the preceding detailed description. Although any suitable insulating material may be employed for the parts which are not designed 60 to carry current, we obtain good results by using porcelain throughout. Various molding compounds, serni-soft rubber or condensation products may also be used.

The specific form of the plug elements includ- 651mg the plug extension shown in the drawing are adequate if porcelain is to be used for manufacturing the same.

In the modification shown in Fig. 10, the cap I36 does not extend to the thumb piece 31, as 70 in the main form, but is merely in the. form of a ring extending over just sufiiciently to hold the translucent member I32 and the plug extension in position. There are certain advantages in a construction as shown in Fig. 10 in that all of the 75 openings |3| which comprise the individual chambers can be seen at the same time. The discoloration is confined to the region of these chambers and the user of the plug can tell at a glance how many of the fuse elements have been blown or burnt out.

We have described our invention in detail in order that those skilled in the art may be instructed in the practice of the same. We limit ourselves, however, only by the scope of the appended claims.

What we claim as new and desire to protect by Letters Patent of the United States is:

1. In a multiple fuse plug, a housing, a plug having a plurality of channels, said plug rotatably supported in the housing, fuse elements supported in the channels, a plug extension having squared projections extending into the channels, and apertures communicating with the channels whereby to interconnect the plug and plug extension and form individual chambers for the fuse elements, and a translucent member closing said apertures to form in effect one wall of said chambers.

2. A multiple fuse plug as defined in claim 1, including an apertured cap extending over the separable plug extension and translucent member, attached to said housing and stationary with respect thereto, said plug extension having a projection extending through said cap for rotating the same.

3. In a multiple fuse plug, a housing, a pair of contacts on the housing, a. plug rotatably supported in the housing, said plug having channels coinciding to provide a spiderlike depression therein, a multiple fuse element disposed in the spiderlike channel, whereby a number of individual fuse elements is provided extending radially from the center of the plug in said channels, a plug extension having squared projections extending into the channels and having apertures communicating with said channels whereby to interconnect the plug extension and plug and form a plurality of closed chambers including portions of said channels, and a translucent member disposed against the plug extension and closing said apertures, and means for successively bridging the individual fuse elements across said housing contacts when the plug is turned.

4. A multiple fuse plug as defined in claim 3, wherein the channels on the plug-extend along the sides thereof, the individual fuse elements extending into the said channels, and a retaining washer extending around the plug and having projections extending into the channels to hold the fuse elements in position.

5. In a multiple fuse plug, a housing having center and shell contacts, a plug having a plurality of radial channels coinciding to form a spiderlike channel said radial channels extending along the sides of the plug, a multiple spiderlike fuse element disposed in the channels and channel extensions, an extension from said center contact on the housing to the center of said multiple fuse element, a spring contact member carried by the housing and in electrical contact with the shell contact adapted to engage the individual fuse elements when the plug is rotated, and means for rotating said plug including a plug extension having projections extending into the channels of said plug, and apertures coinciding with the channels whereby the plug extension and plug are moved together and individual chambers are formed including said chanels, and a translucent member rotatable with theplug extension and closing said apertures.

6. In a multiple fuse plug, a housing closed at one end and open at the other, a screw shell around the lower portion of the housing, a plug carried in said housing, an axis for said plug comprising a pin extending through the closed end of the housing and entirely through the plug to permit rotation of the plug but carry it permanently in said housing, a plurality of grooves on the top of the plug, a spiderlike fuse element carried in the grooves secured at the center by said pin and in electrical contact therewith, a separable plug extension carried at the closed end of the housing adjacent said plug, having projections on the underside thereof engaging corresponding grooves to move said plug upon rotation of said extension, an immovable apertured cap closing the top of the housing and extending over the sides to retain said extension in engagement with the plug, a thumb piece integral with the extension extending through an aperture in the cap for turning said extension, and a spring contact in said housing in connection with said shell for successively engaging a fuse element to complete an electrical path through the pin.

7. In a multiple fuse plug, a housing, a fuse carrying body rotatably but permanently carried in said housing having a plurality of channels on the top surface thereof for carrying the individual fuses, means for rotating said body including a separable cap of insulating material lying on top of said body and having a plurality of projections on the underside thereof for engaging in corresponding channels of the body, an immovable cover to close the housing and retain said cap in engagement with the body, and a thumb piece integral with the cap and extending upwardly from the center thereof through the cover whereby said cap may be moved to rotate said fuse carrying body.

8. A fuse plug comprising a casing, a member rotatably mounted in said'casing and having an axial bore opening to an end face thereof, said end face having a plurality of radial grooves extending to said bore, fusible elements in said grooves, a closure positioned against the said end face and covering the open sides of said grooves, a pin in said bore connected to the radial inner ends of said elements and having a head portion restricting the inner end openings of the grooves in a manner cooperating with said closure to substantially isolate the different elements, a connecting terminal on said plug connected to said pin, a second terminal on said plug, and means operable on rotation of said member to successively connect the outer ends of said elements to said second terminal.

9. In a multiple fuse plug, a housing member having an open upper end and provided with center and shell contacts, a member rotatably mounted centrally of saidhousing member and having a portion thereof projecting from said open end of the housing member for manual engagement to rotate the same with relation to said housing member, a plurality of fuse elements mounted on one of said members within said housing with each element having one end electrically connected with one of said contacts. and having their other ends arranged in circumferentially spaced relation adapted for selective electrical connection with the other of said contacts. a translucent wall extending across said open end of the housing member and mounted in fixed nonrotativerelationtothememberon whichsaid fuse elements are mounted and having portions adjacent and in fixed relation to each fuse element for individual discoloration when the adjacent fuse element is burned out, a spring contact element electrically connected to the other of said contacts and mounted in fixed relation to the other of said members in a position to contact said other ends of the several fuse elements successively in relative rotation of said members, and closure means extending from and cooperating with said manually rotatable member to complete the closure of said upper end of the housing member, said closure means having a single sight opening formed therein and being fixed nonrotatably with respect to the member upon which said spring contact is mounted with said sight opening in alinement with said spring contact so as to expose to view and direct the user's attention to the fuse element in circuit with said spring contact.

10. A multiple fuse plug comprising, in combination, an insulating housing member having an open end and having center and shell contacts at the other end, an adjusting member mounted ,rotatably in said open end of said housing member and having a portion extending from said open end for manual engagement to effect relative rotation of said members, a plurality of fuse elements mounted within said housing member and in fixed relation to one of said members with one end of each element in electrical circuit with one of said contacts and with their other ends arranged in circumferentially spaced relation adapted for selective electrical connection with the other of said contacts, a spring contact element electrically connected to said other of said contacts and mounted in fixed relation to the other one of said members in a position to contact said other ends of said fuse elements successively in relative rotation of said members, a translucent wall extending across said open end of the housing member in fixed non-rotative relation to said fuse elements, said fuse elements having reduced portions located adjacent to the inner side of said translucent wall and in circumferentially spaced relation to each other, means within said housing member and adjacent and in fixed non-rotatlve relation to the inner side of said translucent wall defining a plurality of chambers opening toward and against said inner side of the translucent wall, one such chamber being formed between the reduced portion of each fuse element and said wall and acting to confine the flame and the resulting discoloration to a particular section of said translucent wall, and closure means extending from said rotatable adjusting member along the outer face of said translucent wall and cooperating with said rotatable member to complete the closure of said outer end of the housing member, said closure means being fixed non-rotatably with respect to the member with which said spring contact is associated and having a single sight opening therein positioned for alinement with the particular fuse element in circuit with said spring contact so as to expose and direct the users attention to the fuse element in operative relation at any particular setting of the parts, and by the condition of the exposed portion of the translucent wall to indicate the condition of the particular fuse element in circuit.

BENJAMIN L. M088. FRANCIS J. LANDGRAI'.

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