US2833998A - Electrical outlet - Google Patents

Description

May 6, 1958 .1 M. ALDEN ELECTRICAL OUTLET Filed March 19, 1954 United States Patent O ELECTRICAL OUTLET John M. Alden, Dedham, Mass.

Application March 19, 1954, Serial No. 417,269

2 Claims. (Cl. 339-491) This invention relates to electrical -outlets and more particularly to female outlets such as are mounted on a panel board or upon the rear of a chassis.

Objects of the invention are to provide an electrical outlet which is of a minimum size compatable with the spacing of its contacts, which is attractive in appearance, which is readily mountable, which is rugged in construction, which permits spot welding of the leads to the contacts, which is simple and economical to manufacture and which advances the electrical arts generally.

An outlet according to the present invention comprises a body of a non-conducting material, such as a suitable plastic, having one or more recesses therein for receiving the bayonets of a mating male plug. One side wall of each recess is formed |by an arcuate strip of a conducting material which is restrained transversely but is free to move lengthwise upon being deformed by the insertion of the mating bayonet, thereby to insure good electric contact therebetween. When two recesses are provided as in an outlet for use with the ordinary two wire single phase circuit, the contact strips are preferably placed back to back in adjacent relationship and the connecting leads brought out therebetween so as to minimize the overall size of the outlet. This arrangement of the contacts is preferably obtained by making the body hollow and providing bosses which extend inwardly from two opposing walls to act as a backing therefor. The ends of the leads are preferably mechanically secured to the contact strip, for example, by a tab or tongue to relieve the mechanical strain, and the lead end extending beyond the mechanical connection is spot welded to the strip to insure a good low resistance electrical contact.

These and -other objects and aspects of the invention will be apparent from the following description of a specific embodiment of the invention which refers to a drawing wherein:

Fig. 1 is a front View of an embodiment of the invention having two bayonet receiving recesses;

Fig. 2 is a side elevation view of the embodiment shown in Fig. l;

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

Fig. 4 is a sectional view on line 4-4 of Fig. 2;

Fig. 5 is a sectional view on line 5 5 of Fig. 4;

Fig. 6 is a sectional View on line 6 6 of Fig. 2; and

Figs. 7 and 8 are enlarged fragmentary details, respectively, of two means of fastening the connecting lead to the contact strip.

The embodiment of the invention chosen for the purposes of illustration is a dual electrical outlet which is particularly adapted for use in a conventional 110 or 220 volt circuit such as a single phase A. C. or a D. C. circuit such as requires two conductors for the completion thereof. As can best be seen in Figs. 2 through 4, the outlet comprises a hollow rectilinear body of an electrically non-conducting material which is preferably molded from a suitable plastic material in two separate portions designated 10 and 12 respectively. To opposed sides of the lower body portion each have protruding rice respectively from their upper end a lip 14 (Fig. 3)v formed integrally with the wall. The lips 14 seat in a socket formed in a sheet metal retained 16 by bending the sides of the retainer down and under so that the lower body portion is held with its top surface in the same plane as the retainer end flanges 18, as is best shown in Fig. 4.

The body cover portion 10 and the lower body portion 12 are maintained in assembled relationship by means of a sheet metal clamping member 20 which is provided with a rectangular aperture so that its dependent sides 22 can be bent back underneath the lower lips of the retainer 16. At either end of the clamping member 2l) is a semicircular ange 24 having an aperture 26 which is in alignment with a corresponding aperture 28 (Fig. 4) in the retainer ilange 18 thereby to provide two mounting holes through which screws (not shown) can be inserted to attach the outlet to a panel, chassis or other supporting structure.

As can best be seen in Fig. 7, the electrical contacts 30 for the outlet consist simply of rectangular strips of a resilient electrically conducting material, such as Phosphor bronze, which are bent to the arcuate configuration shown in Fig. 4. As best illustrated in Fig. 3, the width of the cavity in the lower body portion 12 is only enough greater than the width of the contact strip to provide a small clearance when the strip is inserted thereon with its lower end resting upon the bottom wall 32 of the body. The two contacts 30 are maintained in a spaced relationship in the body cavity with their concave faces disposed `back to back by two bosses 34 which are formed integrally with the opposed sides of the lower body portion 12.

The body cover portion 10 is provided with two recesses 36 (Fig. 4) upon its under face for retaining the upper ends of the contact strips 30 which are further separated by a boss 38 which extends downwardly from the cover portion between the bosses 34 in the lower body portion. It is to be particularly noted that with the contact strips in their normal position shown in Fig. 4, the rounded lips 40 which terminate the outer walls of the recesses 36 bear against the convex faces of the contacts 30 to hold the contacts in position but that the recesses are deep enough so that the ends of the contacts strips do not bottom therein.

The inner surfaces of the end walls 42 of the lower body portion 12 are declivous with respect to the outer surfaces so as to form with the adjacent contact two wedge-shaped recesses, access to which is gained through two rectangular apertures 44 in the body cover portion 10. It willbe apparent if the bayonets of a male plug (forming no part of the present invention) are inserted through the apertures 44 the tips thereof will force the contact strips 30 away from the lower body walls 12.

As the contact strips 30 are backed by the bosses 34, the

entering bayonet tips cause an elongating deformation of the contact strips 30 which deforming movement is accommodated by the depth of the cover recesses 36. The resulting strain set up in the contact strips 30 forces the convex surface of the strips into intimate electrical contact with the bayonets without resorting to a complicated shape which would be expensive to manufacture and subject to breakage and fatigue.

The leads 46 are preferably attached to the concave inner surfaces of the contact strips 30 and brought out between the strips through an aperture (Fig. 6) in the bottom wall 32 of the body so that the greatest dimension of the outlet is minimized being only greater than the standard spacing of the male plug bayonets by the thickness of the lower body end walls 42. One preferred manner of attaching the lead 48 to the associated Contact strip 30 is that wherein the bared lead end is carried about a raised tongue 52 in the form of a bight and joined as at 54 heyond the area of contact with the tongue by spot welding asf-isses or other heat fusible means such as soldering or brazing. The described construction has the two-fold advantage of making use of the low electrical resistance resulting from the intimate Contact resulting from the spot weid while obtaining mechanical strength from the tongue so that stress will not be placed upon the spot weld that would result in structural failure due tot the crystallization of the metal of the weld.

An alternate construction which obtains sirnilar results is shown in Fig. 8 wherein mechanical strength is obtained by cutting the lower end of the contact strip to form two tabs 56 and 58 which are folded back over the bared end of the lead 48. Good electrical contact is insured as at 6) by spot welding or otherwise fusing the tip of the lead 4t? which extends beyond the tabs so that no mechanical stress is imposed upon the weld.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

l. An electrical outlet for receiving the bayonets of a mating plug comprising a body of a non-conducting material forrned with a central cavity and two spaced apertures in one end opening into said` cavity for receiving the bayonets, and two arcuate contacts, each having only a single radius of curvature, movably disposed in said cavity with their convex surfaces respectively in abutment with opposed sides of said body directly beneath said apertures, one end of said body having parallel slotted recesses for slidably engaging the ends of said contacts, the other ends of Said contacts resting against the opposite end of said body so that the contacts are free to expand lengthwise into the slotted recesses as the bayonets of the mating plug are inserted between the conducting material including four generally rectilinear side walls which are joined to forni a central cavity, two of the opposed side walls of the body having declivous inner surfaces, the other two opposed walls having longitudinal bosses extending inwardly into said cavity, one end of the body having a central aperture opening into said cavity for the connecting leads of an associated circuit, the other body end having two spaced apertures opening into said cavity contiguous with said declivous side walls for receiving the bayonets of the mating plug, the portion of said other body end between the spaced apertures having two parallel slotted recesses opening into said cavity; and two arcuate contacts, each having only a single radius of curvature, movably disposed in said cavity with their longitudinal edges adjacent the sides of said bosses, the upper end of each contact slidably engaging a respective slotted recess with their opposite ends resting against the body end, one opposite end being respectively on each side of the central-aperture vto bring the convex faces ofthe contacts into abutment respectively with the declivous body sides directly beneath said spaced apertures so that the contacts are free to expand length wise into said slotted recesses as the bayonets of the mating plug are inserted between the convex faces of the contacts and the declivous walls.

References Cited in the file of this patent UNlTED STATES PATENTS McFarlin I une 1,

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