US2686856A - Electric plug - Google Patents

Description

E. CARDONE ELECTRIC PLUG Aug. 17, 1954 Filed July 6, 1951 INVENTOR. 'UGE/V' C4EOGN Patented Aug. 17, 1954 ELECTRIC PLUG Eugene Cardone, Jamaica, N. Y.

Application July 6, 1951,

Serial No. 235,401

8 Claims. (Cl. 200-115.5)

This invention relates to an electric plug and more particularly to an electric plug containing a removable and replaceable safety fuse prong therein.

In most homes where electricity is used it will be noted that there is provided a fuse box at the electrical power line entering the house or building concerned. Such homes are also prcvided with a number of electric outlets at the base or floor boards in the various rooms in addition to the electrical outlets for ceiling lighting and other fixtures. In many instances and particularly where there cult of the power when the whole line with all lighting units and sockets controlled by such fuse is out and a search would have to be made throughout the house or building to determine where the blow-out occurred. The user of the electricity then would have to go the fuse box and replace the blown fuse with a good one, the fuse boxes being usually located in the cellar of the house or building thereby necessitating xtra walking and inconvenience to the person changing the fuse.

With the above noted and other disadvantages in view, it is an object of my invention to provide an electrical plug containing one or more readily removable fuse containing prongs which may be readily inserted into the wall sockets of an electrical line or into electrical receptacle outlets.

Another object of my invention is to provide an electrical plug with one or more easily replaceable fuse terminals to facilitate the location and elimination of short circuits in electrical circuits.

Another object of my invention is to provide an easily constructed electricity conducting wall in which one of the prongs thereof constitutes a fuse integral therewith and which can be easily removed and replaced if the fuse in such prong is blown out.

Still another object of my invention is to provide a plug for use in electric sockets or electrical receptacle outlets now in general use, said plug including tensioned holding means and a removable terminal prong therein having an insulated fusible material forming an integral part of the prong. I

Other objects and features of this invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a sectional vertical view of a preferred embodiment of my invention taken on line II of Fig. 2;

Fig. 2 is a bottom ment;

Fig. 3 is a fragmental side view of a prong and fuse integral therewith in the embodiment shown in Fig. 1;

Fig. 4 is a sectional view taken on line 4-4 of Fig. 3;

Fig. 5 is a perspective view of a spring holding member or housing for one of the terminals forming part of the embodiment shown in Fig. l; and,

Fig. 6 is a sectional view taken on line 6-5 of Fig. 5.

Referring now more particularly to the drawings in which similar reference numerals refer to like parts throughout, I provide a plug l [I with a body l0 made of any suitable material hav ing a high electrical insulation quality, such as hard rubber, Bakelite and the like. Said plug Ill is provided with a central longitudinal opening I I through which extends an insulated sheath containing wire conductors I2 and I3 diverging from said central opening into a well I4 in the plug body It. Said well I4, as will be noted from the drawing, is a depression or recess set in from the base or socket contacting portion I5. Said well has disposed at one side of its longitudinal axis a right angled terminal member or prong I6 extending upwardly from the bottom I! thereof being held in relatively fixed position to said bottom I7 by means of one or more pins I8. Said terminal I6 has a shorter arm I9 fixed to the bottom I? of well I4 by pins I8 and is provided with a threaded opening I9 therethrough for accommodating a screw member 20 for holding conductor I2 against said short arm I9 plan view of my embodi- To the other side of opening II of said plug and diametrically opposite the area of arm I9 there is a deep vertical recess 2I for accommodating a spring housing or detent member 22. It will be noted that said housing 22 has a laterally extending arm 23 which rests on the bottom I! of well I4. Said arm 23 is held in position in said recess and bottom of well I4 by means of pin 24 extending through opening 24 into said bottom I7. Said housing as shown more clearly in Figs. 1 and 5 also has an upwardly extending relatively stiff section 25 integral with arm 23, a bent flat bottom section 26 and an upwardly extending curved yieldable spring section 21. Said spring section 21 is provided with a pair of inwardly bent opposed guide tabs 28 which are perpendicular to the plane of the spring, while the upper part of the spring section is curved inwardly and then outwardly forming the tongue or upper free end 29. Upward section 25 is provided with a semi-circular hole 38 as shown in Fig. 6.

It will be noted that spring housing or detent 22 forms a housing for a removable terminal or prong 3i whose upper part is substantially of the same construction as prong it but whose lower part is provided with a fuse strip 32 for accommodating any type of amperage. Said strip 32 is connected to the metallic terminal iii in any suitable manner such as by soldering or cementing and is an integral part therewith. The lower portion of said fuse strip 32 forms part of and extends into and is connected with a metal base or cup 33 having one or more peripherally extending tongues or projections 3t. Said fuse strip is covered or coated with a transparent insulator 35 made of non-conducting plastic, glass or other suitable material. It will be noted that this insulator extends upwardly from the bottom of metal cup 33 to the prong 3i thereby completely encasing the strip 32. Further, the said cup 33 is in electrical contact with the fuse strip and the detent 22, as shown.

Said prong M with its appurtenent parts can be readily inserted into or moved from the spring housing Upon insertion of the prong 3i with its fuse unit into the housing 22, the lower portion of said prong slides into the spring housing so that its sides are in contact with the upwardly extending section 25 and tongue 29. The latter because of its tension presses the prong against section 25 and as said prong is further pushed into the housing one of the projections 3:2, 1. e., the one abutting section 25 will be caught by the opening 30 in section 25 thereby rigidly retaining the terminal in position in the spring housing in said plug is.

If upon use of the plug herein described the fuse strip is blown and it is desired to replace the prong 3!, it is pressed laterally against the curved free end 29 thereby permitting the projection 3a to slide from opening at whereupon the prong 3i is withdrawn.

It will be noted as shown in Fig. i that the bottom ii of well i l is somewhat lower at the recess area 2! than the bottom where the arm in of prong i6 is set. This is done to prevent wire conductor l3 when held in position against arm 23 by means of screw 36 in threaded opening 3'5 from interfering with the removal or insertion of prong 3!. It will also be noted that fixed prong member is may be replaced by a removable prong with built-in integral fuse exactly the same as prong 3i with its arrangement of parts to allow easy removal and insertion of said prong-fuse combination 3!. Said plug would then be equipped with two removable prong-fuse combinations 3 I.

From the foregoing description taken in conjunction with the accompanying drawings, it will be noted that by my invention I provide a safe and economic plug in which one or more of the prongs or terminals acts as a fuse thereby reducing the amount of inconvenience in replacing or locating blown fuses. Also, the whole line in the circuit is not blown, and it will be further noted that the short will be in the line leading to a particular fixture or appliance. A plug made according to my invention has one Or more fuse prongs which are as rigid as the conventional type of plug. Because of the interlocking feature provided in the plug there is little or no likelihood of the prongs becoming loose or of being easily removed from the plug itself. Such type of plug also has a well in which the floor thereof is set at different levels so as to prevent wire conduits extending into the plug from interfering with the removability or insertion of the replaceable fuse prong member or terminal. Such plug, according to my invention, is safe to use and the fuse containing prong removed and replaced with ease and convenience.

While a preferred embodiment of my invention has been shown and described it is to be understood that various modifications as to form, arrangement of parts and use of materials may be made without department from the spirit and scope of the invention as claimed.

I claim:

1. In an electric plug for use in combination '7 with electrical receptacle outlets now in general use, having a base insulated member for holding a pair of wire conductors from a source of electricity, said plug having a recess therein, the improvement comprising an electroconductive fixed terminal member in said recess in connection with one of the conductors and extending outwardly of the base member, said recess having a bore extending deeper into the than the recess itself, an electroconductive tensicned housing member set in said bore, said member being in connection with the other wire conductor, and removable electroconductive terminal member fixed in said housing member for completing the electric circuit when set in a socket and the like, said removable terminal member having an upper metallic part and a lower part provided with a fuse strip and a metal base making electrical contact with the housing, and a transparent insulator of non-conducting material housing said fuse strip, said insulator extending upwardly of the metal base and beyond the housing member.

2. In an electric plug for use in combination with a conventional electrical receptacle having a base member having a central opening therein for electrical wiring, a well set inwardly of one end of said base member forming a recess for accommodating the terminals of said wiring, the improvement comprising a pair of terminal prong members each in connection with said wiring, one of said prong members being set permanently in the well, and the other is provided with a fusible metal strip integral therewith, and coated with insulated material and a spring housing set inwardly of the recess for removably retaining the last named prong member, said housing having an extension fixed to the well, and a portion adapted to hold the last named pronged member in relatively fixed position therein.

3. In an electric plug for use in combination with conventional electrical receptacle outlets having a base member having an opening extending therethrough for electrical wiring, a well set inwardly of the end of said base member facing the outlet, said flooring being adapted for accommodating the terminals of said wiring, the improvement comprising a pair of terminal prong members in connection with said wiring, one of said prong members being fixed in said well and connected with one of the wiring, the other of said prong members being removable and having a fusible strip integral therewith and covered with transparent insulated material, and a spring tensioned housing in electrical contact with the strip and set in the base member in connection with the other of said wiring and adapted to accommodate and lock said last named prong member said housing forming electrical contact with the bottom of the removable prong member thereby completing the electrical circuit from one prong member to the other when the plug is connected with a source of electricity.

4. A plug according to claim 3, in which the housing has a flat wall and an opposed inwardly curved spring wall, and notched retaining means in the flat wall for fixedly engaging the removable prong member.

5. A plug according to claim 3, in which the bottom of the well around the removable prong is slightly elevated relative to the flooring around the fixed prong to permit easy removal of the prong member without interference from the terminal of the wiring leading to said last named prong member.

6. In an electric plug for a conventional socket having a base of insulating material havin an opening extending therethrough for accommodating electrical wiring, said base having a well of different levels set inwardly of one end of said base member for accommodating the terminals of said wiring, the improvement comprising a pair of binding posts, a pair of terminal prongs in electrical connection with said wiring, and connectible with the posts, one of said prongs being removable and having a fusible strip integral therewith and coated with insulated material, the level of the well around the former prong being lower than the level around the removable prong,

prong, and interengaging electrical contacting means on said last prong and the housing for keeping the prong in fixed position in the base and complete the electric circuit when in connection with a source of electricity.

7. In a removable plug, a removable prong acting as a fuse, comprising an electric conducting exposed member, a fusible alloy strip conwardly of the holder for enclosing the strip and part of the member to prevent shorting in the plug, said alloy strip being in electrical connection with the holder housing.

8. In an electrical plug for use in the conventional type of electrical receptacle outlets having a non-conducting base member having a recessed well facing the outlet when connected therewith and an opening for the passage of wiring therethrough to the recessed well, a pair of binding posts in said well for electrical connection with the wiring, the improvement comprising a terminal prong member in connection with one of posts, a spring locking housing set in the base in electrical connection with the other post, and another terminal having a fuse integral therewith set in the spring locking housing, said fuse being insulated whereby the bottom of the terminal forms electrical contact with the housing, said last terminal having interlocking means for said housing and being integrally replaceable and removable from the housing.

References Cited in the file of this patent UNITED STATES PATENTS

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