US 2989719 A
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Description (OCR text may contain errors)
June 20, 1961 c. J. AARLAHT 2,989,719
CONVERTIBLE ATTACHMENT PLUGS Filed Sept. 11, 1958 ATTORNEY limited This invention relates to electrical fixtures and more particularly to a convertible plug.
It is an object of the present invention to provide a single universally adjustable plug that may be used for all types of two and three socket wall receptacles.
Another object of the present invention is to provide a universal plug of the above type having individually adjustable prongs for selective engagement with various types of standard wall receptacles in a simple and eflicient manner.
Other objects of the invention are to provide a convertible plug bearing the above objects in mind which is of simple construction, has a minimum number of parts, is inexpensive to manufacture and eflicient in operation.
For other objects and for a better understanding of the invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawing, in which:
FIGURES l to 5 are plan views of various kinds of standard wall receptacles with which the plug made in accordance with the present invention may be used;
FIGURE 6 is a side elevational view, with parts broken away, of a convertible plug made in accordance with the present invention;
FIGURE 7 is a plan view of the exterior base plate of the plug shown in FIGURE 6;
FIGURE 8 is a transverse cross sectional view taken along line 8-8 of FIGURE 6;
FIGURE 9 is a transverse cross sectional view taken along line 9-9 of FIGURE 6;
FIGURE 10 is an enlarged fragmentary cross sectional view taken along line 10-10 of FIGURE 9;
FIGURE 11 is an enlarged transverse cross sectional View taken along line 1111 of FIGURE 9;
FIGURE 12 is an enlarged transverse cross sectional view taken along line 12-12 of FIGURE 9; and
FIGURE 13 is an enlarged transverse cross sectional view taken along line 13-13 of FIGURE 9.
Referring now more in detail to the drawing, a convertible plug 15 made in accordance with the present invention is shown to include a main housing within which all of the working parts are disposed. This housing includes a bell shaped dome 16, a wire terminal plate 17. an outside base plate 22, a composite control plate consisting of an outermost plate 18 and innermost plate 20, a cylindrical side wall 28, and spacer pins 26 securing the plates 17 and in assembled relationship. The conduit 30 having power wires 32 and a ground wire 34 extends into the interior of the dome 16 and is connected to terminals 31, 33, mounted onthe wire terminal plate 17, in the manner shown in FIG. 6. The terminals 31 are connected by means of lead wires 36, extending through insulated sleeves 38, to the bases of a pair of prongs 42, only one of which is shown in FIG. 6, and both of which are shown in FIG. 8.
As is more clearly shown in FIGURES 7 through 13 of the drawing, the base 40 of each prong 42 includes a pair of annular flanges 41 and 43 arranged in spaced apart relationship on said base with the flange 43, which has a diameter larger than the diameter of the flange 41, adjacent to the end of the base 40 to which the lead wire 36 is connected. The flange 41 of the base 40 is rotatably supported within an enlarged counterbore 48 in the innermost plate 20 of the control member, with which smaller bores 44, 46 communicate, as is specifically shown in FIG. 13. As a result the prongs 42 are rotatable within these bores 44, 46, 48, into a predetermined position. The outside closure plate 22 has a pair of three sided slots 50, each providing three diiferent positions of orientation for the prongs 42, so as to be accommodated within any one of the pairs of the sockets 81, 81a, 81b illustrated in FIGURES l to 3 of the drawing. Screws 54 releasably secure the outside plate 22 to the associated elements, so that it may be removed and the prongs 42 rotated into the desired position, following which the plate 22 is placed with the prongs extending outwardly through the selected ones of the slots in the three sided openings 50.
The control plates 18, 20 are also provided with T- shaped slots 60, 56, between which an enlarged T-shaped slot 58 is disposed. At two of the three corners of the T-shaped slot 56 on the inner member 20, the slot is enlarged to provide enlarged access openings 61 into which the smaller flange 59 carried by each base of both the ground post 62 and ground blade 68 may be slidably received. Ground wires 72, leading from the terminal 33, are connected respectively to the bases of the ground post 62 and the ground blade 68, in the manner shown in FIG. 6. The larger flange 66 is maintained in sliding contact with the surface of the inside control plate 20 when either the ground post or ground blade is extended. The outside plate 22 is also provided with a central opening 64 having diametrically opposite extending slots 70 for selectively receiving the ground blade 68 when moved into alignment therewith.
A guide pin 74 is also provided for each base 75 of the ground post and ground blade so as to guide such element for selective longitudinal movement into and out of proper position with the central bore 64 of the outside plate 22. Compression springs 76 associated with each such guide pin 74 normally urges the ground post or ground blade outwardly toward the extended position.
In actual use, the plug made in accordance with the present invention can be adjusted to he used with any one of the receptacles illustrated in FIGURES 1 to 5 of the drawing. In FIGURE 1, a conventional outlet 80 is shown wherein the sockets 81 are in spaced apart parallel relationship in the absence of any ground socket. As a result, the plug 15 is adjusted so as to extend both the ground blade and ground post into the interior of the housing and the prongs 42 placed in spaced apart parallel relationship. When adjusting the plug for use with the receptacle 80a illustrated in FIGURE 2 of the drawing, where the sockets 81a are contained within a substantially single plane, the plug is adjusted in a similar manner,
except that the prongs 42 are rotated degrees out of I the position used in connection with the receptacle as shown in FIGURE 1.
In using the plug for the receptacle illustrated in FIG- URE 3, the prongs 42 are rotated to correspond to the sockets 81b and the ground blade 68 is extended into the position of the ground socket 82.
In FIGURE 4, the sockets 81b are in the same position, but the ground socket 82a of the receptacle 80c requires that the ground blade 68 be rotated 90 degrees out of the position used when connected with the receptacle of FIGURE 3.
Finally, in using the receptacle 802;! shown in FIGURE 5 of the drawing, the prongs 42 are returned to the original spaced apart parallel relationship, the ground blade 68 is inserted into the interior of the housing, and the ground post 62 is extended outwardly through the central openings of the control plates to be received within the ground socket 83.
While various changes may be made in the detail construction, it shall be understood that such changes shall be within the spirit and scope of the present invention as defined by the appended claim.
What I claim as new and desire to protect by Letters Patent of the United States is:
A convertible plug comprising, in combination, a housing having a terminal wire plate at one end, a composite control plate assembly at the opposite end, said control plate assembly including an outermost plate and an innermost plate arranged face to face with the outermost plate, spacer pins securing the terminal wire plate in assembly relationship with the innermost plate of said control plate assembly, a plurality of bores formed in said control plate assembly, a pair of prongs, means supporting said prongs in the bores of said control plate assembly for relative rotation about individual longitudinal axes whereby said prongs are adapted to be arranged in predetermined angular positions with respect to each other, said prongs being electrically connected to terminals on said terminal wire plate, an outside base plate arranged face to face with the outermost plate of said control plate assembly, a plurality of angularly arranged openings in said outside base plate through which said prongs project and are thereby retained in predetermined adjusted positions, and means connecting said outside base plate with the outermost plate of said control plate assembly whereby said outside base plate is detachable from said control plate so that said prongs can be rotated in the control plate assembly from one adjusted position to another adjusted position when the outside base plate is removed from the plug.
References Cited in the file of this patent UNITED STATES PATENTS