Electrical connector with embedded canted coil spring

0001Electrical connectors provide the mechanical and electrical interface between two mating parts. In general, they all have the same requirements, i.e., low resistivity and robust mechanical connective properties to withstand the environment. The resistance is a function of the number of contact points, surface condition, and the normal force at the point of contact. The normal force must be high enough to break through any surface film but not so high that it impedes the connection. A scraping or cleaning action is also desirable as an aide to oxide or surface film removal.

0002It is also highly desirable to have a connecting device that will operate over a wide range of tolerances and surface eccentricities without degrading electrical performance. And of course, cost and size are usually important considerations as well in addition to maintaining high conductivity in a high vibration environment

0003A number of techniques have been developed for conductors. In general, they employ various types of louvers or baskets to provide multiple contact points with adequate normal force levels. <patcit id="pcit0001" dnum="US3107966A"><text>U.S. Patent 3,107,966, Bonhomme</text></patcit>, teaches a wire basket. <patcit id="pcit0002" dnum="US4720157A"><text>U.S. Patent 4,720,157, Nestor</text></patcit>, teaches the use of strip springs. <patcit id="pcit0003" dnum="US3980387A"><text>U.S. Patent 3,980,387, Neidecker</text></patcit>, teaches the use of louvered sheet metal. In all three, the normal force is furnished by the spring action of the basket, strip or louver. The normal force applied by the device is a function of the amount of deflection of the individual elements.

0004The present invention replaces the louvers, wire baskets, and the strip springs with a canted coil spring mounted in a helical groove in a connector housing. The canted coil spring provides multiple contact points with the male portion of the connector. The housing can be molded from an insulting material or fabricated from a conductive material depending upon the end use of the connector. The spring can be fabricated from a variety of metal alloy such as platinum iridium. The spring can be plated to enhance conductivity. The canted coil spring has the advantage of nearly constant force over a wide deflection range so that the connector can accommodate a wide tolerance range as well as surface eccentricities. The axial spring has excellent surface film removal qualities, particularly by spring design. The ability to use the canted coil spring permits a very high contact point density permitting a more compact connector than other techniques.

0005<patcit id="pcit0004" dnum="US6966802B2"><text>US 6,966,802 B2</text></patcit> discloses a female electrical connector consisting of a body having a bore therethrough for receiving an electrical plug, a helical groove formed in the bore and protruding therefrom for providing both electrical connection to the plug and retention of the plug within the bore along with a connecting lug embedded into the body, surrounded by the bore interconnected with the spring and having a wire segment extending exterior to the body.

0006This is contrasted to the present invention: For example, the connecting lug which is disposed in the body is welded to the spring includes a wire segment extending exterior to the body for obvious electrical contact purposes and a connecting lug has ends which are embedded into the body to affix the connecting lug to an end to the body. In contrast, with <patcit id="pcit0005" dnum="US6966802B2"><text>US 6,966,802 B2</text></patcit>, the present invention provides a spring, which is not welded to the connecting lug for conductive purposes in view of the fact that the connecting lug of <patcit id="pcit0006" dnum="US6966802B2"><text>US 6,966,802 B2</text></patcit> is formed on the receiving element, which is plastic. Further, there are no ends of the connecting lug which are embedded into the body according to <patcit id="pcit0007" dnum="US6966802B2"><text>US 6,966,802 B2</text></patcit>.

SUMMARY OF THE INVENTION

0007A female electrical connector in accordance with the present invention generally includes a body having a bore therethrough for receiving an electrical plug along with a helical groove formed in the bore.

0008A canted coil spring is disposed in the helical groove and protrudes therefrom in order to provide both electrical connection to the plug and to retain the plug within the bore.

0009A connecting lug is embedded into the body which surrounds the bore and is interconnected with the spring and further includes a wire segment extending exterior to the body in order to provide electrical communication from an exterior source through the lug coil spring and plug.

0010The body may be formed from a non-conductive material and the groove may be flat, V-bottom, or have a tapered bottom. These various groove configurations may be utilized with either radial canted coil springs or axial canted coil springs depending upon the desired force characteristics both retaining the plug within the bore and for establishing and maintaining electrical continuity.

BRIEF DESCRIPTION OF THE DRAWINGS

0011The advantages and features of the present invention will be better understood by the following description when considered in conjunction with the accompanying drawings, in which: <ul id="ul0001" list-style="none"><li><figref idref="f0001">Figure 1</figref> is a cross sectional view of the female connector in accordance with the present invention generally showing a body having a bore therethrough for receiving an electrical plug along with a helical groove formed in the bore, a canted coil spring disposed in the helical groove and an embedded connecting lug;</li><li><figref idref="f0001">Figure 2</figref> is an end view of the connector shown in <figref idref="f0001">Figure 1</figref> more clearly illustrating a spring length welded to the embedded conductive lug along with a wire segment extending exterior to the body;</li><li><figref idref="f0002">Figures 3 and 4</figref> illustrate an alternative embodiment of the present invention in which the groove includes a flat bottom;</li><li><figref idref="f0002">Figures 5 and 6</figref> illustrate yet another embodiment of the present invention which includes a helical groove having a tapered bottom;</li><li><figref idref="f0002">Figure 7</figref> is a plan view of an axial spring length suitable for the present invention; and</li><li><figref idref="f0002">Figure 8</figref> is a plan view of a radial spring length suitable for use in the present invention.</li></ul>

DETAILED DESCRIPTION

0012With reference to <figref idref="f0001">Figures 1 and 2</figref>, there is shown a female electrical connector 10 in accordance with the present invention shown with a male connector, or plug, 12 shown in dashed line inserted through a bore 18 in a body 20 of the connector 10, the bore 18 being sized for receiving the lug 12 by way of a plug head 22.

0013The body 20 is preferably formed from an insulating material and a helical groove 26 is formed with a bore 18. In the embodiment 10, the groove includes a V-bottom 30 and canted coil spring is disposed in the groove 26 with an exposed portion 38 contacting the plug head 22 and providing sufficient force thereagainst to retain the plug head 22 within the bore 18.

0014A connecting lug 42 is provided and preferably disposed on an end 44 of the body 20 and is preferably secured therein by lug ends 48 embedded into the body 20.

0015As more clearly shown in <figref idref="f0001">Figure 2</figref>, the spring 34 includes a length 52 welded to the connecting lug which surrounds the bore 18 and includes a wire segment 56 extending exterior to the body 20.

0016<figref idref="f0002">Figures 3 and 4</figref> illustrate alternative embodiment 60 in accordance with the present invention which includes a body 62 having a helical groove 64 with a flat bottom 66.

0017Alternatively, as shown in <figref idref="f0002">Figures 5 and 6</figref>, an embodiment 70 in accordance with the present invention may include a body 72 having a helical groove 74 with a tapered bottom 76.

0018Either an axial spring 80, as shown in <figref idref="f0002">Figure 7</figref>, or a radial spring 82 shown in <figref idref="f0002">Figure 8</figref> may be disposed in the grooves 26, 64, 74 with the various groove 26, 64, 74 configurations, the insertion and retention force requirements coupled with the electrical properties will determine the specific design of the spring, spring length and material be it radial or axial.

0019In addition, the insertion and holding forces are determined by the spring design and material. A complete description of the radial and axial springs suitable for use in the present invention and the groove configurations for determining insertion and holding forces are set forth in <patcit id="pcit0008" dnum="US4893795A"><text>U.S. Patent numbers 4,893,795</text></patcit>, <patcit id="pcit0009" dnum="US4876781A"><text>4,876,781</text></patcit>, <patcit id="pcit0010" dnum="US4974821A"><text>4,974,821</text></patcit>, <patcit id="pcit0011" dnum="US5108078A"><text>5,108,078</text></patcit>, <patcit id="pcit0012" dnum="US5139243A"><text>5,139,243</text></patcit>, <patcit id="pcit0013" dnum="US5139276A"><text>5,139,276</text></patcit>, <patcit id="pcit0014" dnum="US5082390A"><text>5,082,390</text></patcit>, <patcit id="pcit0015" dnum="US5091606A"><text>5,091,606</text></patcit>, <patcit id="pcit0016" dnum="US5411348A"><text>5,411,348</text></patcit>,<patcit id="pcit0017" dnum="US5545842A"><text> 5,545,842</text></patcit>, <patcit id="pcit0018" dnum="US5615870A"><text>5,615,870</text></patcit>, <patcit id="pcit0019" dnum="US5709371A"><text>5,709,371</text></patcit> and <patcit id="pcit0020" dnum="US5791638A"><text>5,791,638 all to Balsells</text></patcit>.

0020Although there has been hereinabove described a specific electrical connector with embedded canted coil spring in accordance with the present invention for the purpose of illustrating the manner in which the invention may be used to advantage, it should be appreciated that the invention is not limited thereto. That is, the present invention may suitably comprise, consist of, or consist essentially of the recited elements. Further, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein. Accordingly, any and all modifications, variations or equivalent arrangements which may occur to those skilled in the art, should be considered to be within the scope of the present invention as defined in the appended claims.