US3439315A - Electrical contact strip - Google Patents

Description

April 1969 H. R. HAMEL ETAL 3,439,315

ELECTRICAL CONTACT STRIP Filed July 17, 1967 FIG.|

INVENTOR. #AIPOL-D R. HAMEL BY aeNe sr 14 0/572;

/4 7'70/PNEY8 April 15, 1969 H. R. HAMEL ETAL ELECTRI CAL CQNTACT STRIP Sheet Filed July 17, 1967 United States Patent US. Cl. 339-242 6 Claims ABSTRACT OF THE DISCLOSURE An elongated electrical contact strip for use in a cube tap, and including first and second end to end receptacles. The first receptacle is formed by first and secondary substantially coplanar, transversely spaced apart side portions, which are offset above the longitudinal center plane of the strip and a first center strip portion interposed between the side portions, but disposed below the center plane. The first side portion includes first and second oppositely disposed end portions, the center strip portion includes third and fourth oppositely disposed end portions, and the second side portion includes fifth and sixth oppositely disposed end portions, the first and fifth end portions being disposed at one end of the first receptacle, coplanar, and angled longitudinally outwardly and downwardly to the center plane, and the third end portion disposed at said one end and angling outwardly and upwardly to the central plane.

The second receptacle is disposed at said one end of said first receptacle and includes third and fourth transversely spaced apart side portions, substantially coplanar with the first center strip portion, and a second center strip portion substantially coplanar with the first and second side portions. The third side portion includes seventh and eighth oppositely disposed end portions; the second center strip portion includes ninth and tenth oppositely disposed end portions; and the fourth side portion includes eleventh and twelfth oppositely disposed end portions, the seventh end portion being coplanar with the first end portion and being joined with a portion thereof. The ninth end portion is coplanar with the third end portion, and a portion thereof is joined therewith, the remainder of the ninth end portion being joined with the first end portion. The eleventh end portion is coplanar with the fifth end portion, and a portion thereof joins therewith, the remainder of the eleventh end portion being joined with the third end portion.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates generally to electrical cube taps and more particularly to contact strips for use in such cube taps.

Description of prior art Many of the presently known cube taps for mating with a plurality of plugs include contact strips and some of these strips form a plurality of plug prong receivable receptacles. Other known contact strips form receptacles which tightly receive the plug prongs, for example, the contact strips shown in Patents Nos. 3,241,096 and 2,981,- 926. However, it is desirable to provide a contact strip having a relatively short overall length and which holds the plug prongs firmly and securely.

Summary of the invention The contact strip of present invention includes first and second, end to end, plug prong receptacles. The first receptacle is formed by transversely spaced apart, substantially coplanar, first and second side portions that are raised from the central plane of the strip, and a first center strip portion depressed below such center plane. The second receptacle is formed by third and fourth side portions pressed below the center plane of the strip, and a second center strip portion raised above the center plane. A particular advantage of the strip of this invention is the arrangernent of the adjacent end portions of the first and second receptacles to enable the overall length of the strip to be relatively short. One end portion of the first side portion extends downwardly to the center plane where part of it terminates and the remainder of it projects therebeyond and forms an end wall for the third side portion. The second center strip portion includes an end wall adjacent the first receptacle that extends downwardly to the center plane where a portion of it joins the terminated part of the first side portion end wall, the remainder of such center strip portion end wall projecting below the center plane and forming a portion of an end wall for the first center strip portion. The remainder of the end wall of the first center strip portion terminates at the center plane. The fourth side portion includes an end wall that angles upwardly to the center plane where a portion of it joins with the terminated remainder of the first center strip end portion, and the remainder of such wall projects upwardly beyond the center plane to form an end wall for the second side portion.

Other features and the advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the invention is illustrated.

Brief description of the drawings FIG. 1 is a top view of an electrical cube tap including a pair of contact strips embodying the present invention;

FIG. 2 is a bottom view of the cube tap shown in FIG. 1;

FIG. 3 is a vertical sectional view, in enlarged scale, taken along line 33 of FIG. 1;

FIG. 4 is a horizontal sectional view, in enlarged scale, taken along the line 4-4 of FIG. 3;

FIG. 5 is a side view, in reduced scale, of the cube tap shown in FIG. 1, and showing the outline of an included contact strip in broken lines;

FIG. 6 is a top detail view, in further enlarged scale, of a contact strip included in the cube tap shown in FIG. 1;

FIG. 7 is a side view taken along the line 7-7 of FIG. 6;

FIG. 8 is an end view taken along the line 8-8 of FIG. 6;

FIG. 9 is a vertical sectional view taken along the line 99 of FIG. 6.

Detailed description of the preferred embodiment Referring to FIGS. 1 and 4, the electrical cube tap T includes a pair of contact strips S embodying the present invention. The cube tap T includes two pairs of plug prong receiving passages P extending in from its top side and a single pair of such passages disposed intermediate the top pairs and extending in from the bottom side. Each of the strips S include three, end to end, plug prong receiving receptacles generally designated 21, 23 and 25, one of such receptacles being aligned with each one of the respective passages P for receiving a plug prong, or blade (not shown), inserted into such passage.

Referring to FIGS. 1 through 4, the cube tap T is conveniently molded from plastic, and includes a central longitudinal cooling cavity 31. A particular advantage of the strips S of this invention is that they are relatively short, thus enabling the cube tap T to be relatively compact.

The strips S are conveniently pressed from a fiat strip of somewhat resilient, electrically conductive metal, the ends of such strip of metal remaining in the plane 33 (FIG. 7) of the unformed strip. Referring to FIGS. 4, 6 and 7, the right hand receptacle 21 of the strip S is formed by first and second spaced apart side portions 37 and 39, respectively, which are offset above the center plane 33 and a center strip portion 41 interposed therebetween and offset below the center plane. The first side portion 37 is wider than the second side portion 39 and is canted to slope outwardly and upwardly toward its outer edge 43 to assist in leading a plug blade into the receptacle 21. The side portion 37 includes oppositely disposed first and second end portions 45 and 47, respectively, which slope longitudinally outwardly and downwardly to the center plane 33. The second, or right, end portion 47 joins, on its lower end, with an end band 51. The second side portion 39 also includes first and second oppositely disposed end portions 53 and 55, respectively, which angle longitudinally outwardly and downwardly to the center plane 33 where the right end portion 55 joins with the end band 51. The center strip portion 41 includes oppositely disposed first and second end portions 59 and 61, respectively, which angle longitudinally outwardly and upwardly to the center plane 33 where the right end portion 61 joins with the end band 51.

The second, or middle, receptacle 23 is formed similar to the receptacle 21 and includes opposite side portions 65 and 67, depressed below the center plane 33, such side portions being herein referred to as third and fourth side portions, respectively, to avoid confusion with the above referred to first and second side portions 37 and 39, respectively. A center strip portion 68 is interposed between the side portions 65 and 67 and is raised above the center plane 33. The third side portion 65 is narrower than the first side portion 37 and includes oppositely disposed end portions 69 and 71 which angle longitudinally outwardly away from each other and upwardly to the center plane 33. It is a particular advantage of the strip S of this invention that the end portion 71 is in the same plane as the end portion 45, as best seen in FIGS. 6 and 7. The fourth side portion 67 includes a pair of oppositely disposed end portions 73 and 75 which are coplanar with the end portions 69 and 71 and, additionally, the end portion 75 is coplanar with the end portion 53 and is joined therewith. The section 79 of the end portion not joined by the end portion 53 is joined with a section of the end portion 59. The wide side portion 67 is canted with the outside edge 80 lowered (FIG. 9) to assist in leading the mating plug blade into the receptacle 23.

The center strip portion 68 includes oppositely disposed end portions 81 and 83 which angle longitudinally outwardly away from one another and downwardly to the center plane 33. The right end portion 83 is coplanar with the end portion 59 and is joined with a transverse portion thereof. The remainder 85 of the end portion 83 meets, and joins, with the end portion 45 at the level of the center plane 33.

The left hand receptacle 25, is formed similarly to the receptacle 21 and includes opposite side portions 91 and 93 which are raised above the center plane 33and include respective pairs of outwardly and downwardly angled end portions 95 and 97, and 99 and 101. The end portions 97 and 101 are coplanar with, and joined, to the respective end portions 69 and 73. The lower ends of the end portions 95 and 99 are connected with a transverse end band 105. The side portion 91 is tilted upwardly on its outer edge 106 to assist in leading a plug blade into receptacle 25. A center strip portion 107 is interposed between the side portions 91 and 93 and is disposed below the center plane 33. The center strip portion 107 includes a pair of oppositely disposed end portions 111 and 113 which angle longitudinally outwardly from one another and upwardly to the center plane 33. The end portion 113 is coplanar with, and joining to, the end portion 81 and the upper end of the end portion 111 is connected to the end band 105.

A connector tab, generally designated 115, is joined adjacent the left end band 105 and includes oppositely disposed upturned sides 117 and 119.

The cube tap T is manufactured by attaching one strip S to a positive lead 121 and a second strip S to a negative lead 123. Such attachment is accomplished by inserting the respective bare wires of the leads 121 and 123 into the respective connector tabs 115, and then bending the sides 117 and 119 inwardly over such wires. The strips S are then placed in a mold with the respective receptacles 21, 23 and 25 disposed in side by side relation, and plastic is then injected into the mold to form the body of the cube tap T.

A plug (not shown) is connected with the cube tap T, by inserting the plug blades into a pair of passages P and when the leading tips of such blades reach the respective outside confronting edge 52, or 106 of the respective side portion 37, 67 or 91, such tips will be led into the respective receptacle 21, 23 or 25. When the plug blade (not shown) passes into the respective receptacle the cooperating pair of side portions and center strip portion will be spread apart. The side and center strip portions will be bowed outwardly from the center plane 33 and the respective resilient angled end portions will assume a more upright orientation to widen the receptacle. It will be clear that the fully inserted plug blade will be held securely in, and firmly contacting, the respective receptacle, thus preventing accidental disconnection of the cube tap T and plug (not shown).

In addition to securely holding the mating plug blade (not shown), a particular advantage of this invention is that the overall length of the entire three receptacle strip S is relatively short, thus enabling the cube tap T itself to be relatively compact in size.

Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention.

We claim:

1. An elongated electrical contact strip for use in a cube tap and adapted to receive like polarity prongs of first and second plugs, said contact strip comprising:

a first receptacle for receiving a prong of said first plug and including;

a first side portion, offset above the longitudinal center plane of said contact strip, and having oppositely disposed first and second end portions, which extend downwardly to said center plane;

a first central strip portion offset below said center plane and having oppositely disposed third and fourth end portions which extend upwardly to said center plane;

a second side portion substantially coplanar with said first side portion and having oppositely disposed fifth and sixth end portions which extend downwardly to said center plane;

said first side, central, and second side portions cooperating to define a transverse prong passage for tightly receiving said prong of said one plug;

a second receptacle, disposed at one end of said first receptacle, for receiving a prong of said second plug and including;

a third side portion disposed on the same side of said strip as said first side portion, offset below said center plane, and having oppositely disposed seventh and eighth end portions, which extend upwardly to said center plane, said seventh end portion being coplanar with said first end portion and joined to a portion thereof;

a central strip portion adjacent the inner side of said third side portion, ofiset above said central plane, and having ninth and tenth end portions which extend downwardly to said center plane, said ninth end portion being coplanar with said third end portion and having a portion joined therewith, the remainder of said ninth end portion being connected with said first end portion;

a fourth side portion coplanar with said third side portion and disposed on the same side of said strip as said second side portion, and having eleventh and twelfth end portions which extend upwardly to said center plane, said eleventh end portion being coplaner with said fifth end portion and having a portion joined therewith, the remaining portionof said eleventh end portion being connected to said third end portion;

said third side, second central, and fourth side portions cooperating to define a transverse prong passage which tightly receives the prong of said second plug.

2. An electrical contact strip as set forth in claim 1 wherein said first side portion is canted upwardly on its outside edge to assist in leading a plug prong into said first receptacle.

3. An electrical contact strip as set forth in claim 1 wherein said third side portion is canted downwardly on its outer edge to guide a plug prong into said second receptacle.

4. An electrical contact strip as set forth in claim 1 wherein the plug prong receiving passages formed by said first and second receptacles are smaller in cross section than the cross section of the plug prongs to be received and wherein said end portions are at an angle from the vertical and are sufiiciently resilient to enable said respective cooperating side and center strip portions to be spread apart by said plug prongs whereby said respective' cooperating side and center strip portions will be urged inwardly by said respective end portion to tightly hold said plug prong.

5. An electrical contact strip as set forth in claim 4 wherein said first side portion is canted upwardly on its outside edge to assist in leading a plug prong into said first receptacle.

6. An electrical contact strip as set forth in claim 4 wherein said third portion is canted downwardly on its outer edge to guide a plug prong into said second receptacle.

References Cited UNITED STATES PATENTS 3/1966 Miller 339-157 11/1967 Rodgers 339-498 US. Cl. X.R.

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