US2478570A - Twistable blade plug - Google Patents

Description

Aug. 9, 1949. f

w. J. CREHA'N 2,478,570

TwIsTABLE BLADE PLUG Filed July 2, 1946 33 .iff

Patented Aug. 9, 1949 TWISTABLE BLADE'PLUG- 1 William J. Crehan, Chicago, Ill., assignor, by

mesne assignments, to Ralph D. Collins, Beverly Hills, Calif.

Application July Z, 1946, Serial No. 680,898

1 Claim.

This invention relates to twistable blade plugs for use generally as electrical connectors.

Among other objects, the invention aims to provide an improved self-holding plug which resists considerable pulling force which would tend to accidentally separate the plug from the socket while still being readily removable when desired.

Other objects and advantages will be apparent from the following description, taken together with the accompanying drawings, of illustrative embodiments of the invention, and in which drawings- Figure 1 shows an elevational view of a form of plug embodying the invention;

Figure 2 is a plan View of the plug of Figure 1 and showing the blades in position in which they are placed in one operative relation; and

Figure 3 is a view showing a twisted position of the plug shown in Figures 1 and 2 to place the blades in another operative relation.

Referring in detail to the illustrative constructions shown in the drawings and turning first to Figure 1, there is here shown the plug body 32 which is advantageously molded in one piece of an elastic flexible insulating material, such as soft rubber or other rubber-like elastomer, for example a suitable material being Buna-S with appropriate compounding agents well known to the art, which when vulcanized has a Shore durometer hardness reading of the order of say 40 to 60.

As here shown, the body 32 carries a pair of metallic contact blades 33 and 34, which, in this instance, are of nat brass strip metal stock and embedded in the body 32. The embedded ends of the contacts may have holes therein through which may be passed and soldered the bared ends of separate insulated conductors or wires, which, in this instance, are contained in a cable which includes upon its exterior a vulcanized rubber-like jacket, the cable passing into the lower end of the plug body 32 through a bore-like cavity therein.

In accordance with the usual practice, the blades 33 and 34 at their upper ends project longitudinally from the face of the plug body as jacks or prongs which are to be inserted into the usual socket connector of a wall or other outlet for a source of electric current, but in this instance, instead of the blade ends 33 and 34 being initially located in normal position for insertion into the socket, they are, in accordance with the present invention, initially set in the body relatively at positions offset from normal with respect to each other. The blades 33 and 34 are initially set in a common plane, the body 32 being in this instance elongated or oi somewhat elliptical formation as seen by looking at the face 35 of the body 32 as in the plan view of Figure 2. In this instance, the Ibody 32 may be flexed, or folded upon itself before the plug is inserted in the socket at all, and about say a central longitudinal axis 36, until the body 32 assumes a U-shape formation substantially as shown in Figure 3, at which time the blades 33 and 34 are now in parallel planes approximately one-half inch apart. To provide for this distance, the distance across the face 35 of the body 32 in its shorter transverse dimension should be approximately one-half inch, so that the ends 31 and 38 of the body 32 may be flexed in either direction about the longitudinal axis 33 to bring the blades 33 and 34 from the initially out of normal position of Figure 1 to a normal position approximately one-half inch apart, as in Figure 3.

As here constructed and arranged the soft rubber body permits distortion to twist the blades for insertion in the standard socket openings (not shown) While the restorative force of the rubber provides a torsional stress on the blades which holds them in the openings.

Furthermore the plug may be used with a less standard but not uncommon form of socket openings in which the transversely elongated socket openings are in a common plane rather than in parallel planes, and for this purpose the plug need not be bent around as in Fig. 3 but may be used as in Figs. 1 and 2 by simply squeezing the plug body together to bring the blades closer together while still maintaining them in a common plane as in Fig. 2.

Such changes may be made as fall within the scope of the appended claim without departing from the invention.

The invention having been described, what is here claimed is:

A twistable blade plug comprising a body of soft insulating elastomeric material sufficiently wider in one direction than the other so that the body may be exed transversely upon itself about its longitudinal axis to somewhat U-shape, a pair of flat strip contact blades carried in said body substantially parallel with and on opposite sides of said axis and projecting from a common face of said body, said blades before the body is flexed being carried with adjacent flat faces of the blades respectively facing in the same direction, whereby while still maintaining 3 '4: Athe blades parallel the body may be folded upon UNITED STATES PATENTSI itself to rotate the |blades into position with adjacent at faces of the blades respectively gulegg GQ01311119 De? a2'te1941 facing in opposite directions for insertion of the 7,78615 Watts "Oct '14 1930 blades in correspondingly shaped parallel open- 5 ingsm an electrical Socket 1,981,460 Mlller NOV- 20, 1934 2,316,555 Bugg Apr. 13, 1943 K v K 2,396,725 Thomas-Jr. Mar, 19, 1946 WILLIM'J- CREE-AN- 2,408,`583 sions oct; 1, 1946 REFERENCES CITED f Y 1 FOREIGN PATENTS Number Countr Date The OHOWmg feferences are 0f IgG-01'@- 11'1- 1111 263,208 Great Britm Dec. 21, 1926 me 0f this Patent: 771,775 Emme July so, 1934t

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