US3022481A - Electrical connector - Google Patents

Description

Feb. 20, 1962 'r. STEPOWAY 3,022,481

ELECTRICAL CONNECTOR Filed Feb. 26, 1960 20 v '8 INVENTOR THEODORE STE PO WAY ATTORNEY United States Patent 3,022,481 ELECTRICAL CONNECTOR Theodore Stepoway, 713 Ranier Circle, Garland, Tex. Filed Feb. 26, 1960, Ser. No. 11,216 4 Claims. (Cl. 339-75) This invention relates to an electrical connector eminently suited for establishing circuits in conjunction with printed circuit cards.

It is important in establishing electrical connections with printed circuit cards and boards that the contacts be firm regardless of the presence of thickness variations in the support or the conductors themselves. It is also desirable that the connections be established and broken quickly when needed. It is quite necessary that circuit conditions be maintained without accidental interruption.

All of these results have been achieved in accordance with the present invention which includes among its objects the provision of an electrical connector comprising a frame providing a bearing surface for a conductive strip, the frame supporting a resilient contact element spaced relatively to the conductive strip, a cam having a surface of electrical insulation movably supported with respect to the contact element for urging the contact element towards the conductive strip, means for moving the cam with respect to the conductive strip, and detent means for maintaining the cam in adjusted position. The cam is preferably rotatable and may be composed entirely of electrical insulation. A ratchet and pawl mechanism is preferably provided for latching the cam in any of a plurality of adjusted positions, and in a preferred form of the invention, the bearing surface supports an electrical conductive strip which is electrically connected to the resilient contact element and to such additional conductors as may be required by the functions desired.

In a preferred form of the invention there are a plurality of resiliently mounted contact elements carried by the frame spaced from the conductive strips and from one another and the cam simultaneously engages these elements for urging them toward the conductive strips for engagement with a plurality of conductors on an intervening printed circuit card and the like. The plural contact elements may be supported in substantial alignment with the conductive strips and may assume the form of leaf springs. Where a plurality of such contact elements are present, the bearing surface may support spaced electrical conductive strips opposite such elements respectively.

A more complete understanding of the invention will follow from a description of the accompanying drawings wherein:

FIG. 1 is a perspective view of an electrical connector conforming to the present invention;

FIG. 2 is a front elevation of the connector shown in FIG. 1;

FIG. 3 is a sectional elevation taken along line 3-3 of FIG. 2;

FIG. 4 is an elevation of the right end of the connector as viewed in FIG. 2;

FIG. 5 is a fragmentary plan view of the connector;

FIG. 6 is a fragmentary perspective view depicting the detent mechanism contemplated; and

FIG. 7 is a sectional elevation, similar to FIG. 3, showing another arrangement of terminals.

A frame or housing 10 of electrical non-conductive material is provided with an internal chamber 12 providing a bottom wall 14 defining a bearing surface. A plurality of conductive strips 16 are arranged in spaced relationship along the bearing surface, and corresponding and super-imposed relative to each of these conductive strips there is shown a resilient leaf spring contact element 18. As shown in FIG. 3, these conductive strips and contact elements may be provided with enlargements 20 about which the insulating resinous or comparable thermoplastic material constituting the frame or housing may be molded. As also depicted in FIG. 3, ends 22 of the conductive strips and contact elements may project through the rear wall of the frame or housing to facilitate the attachment of leads by means of solder or other conventional materials. The internal chamber 12 also provides an upper wall or bearing surface 24 for engagement with the contact elements along portions of their lengths to limit their upward movement with respect to the conductive strips 16, each contact element 18 having a free end projecting beyond the bearing surface 24 which overlies the corresponding conductive strip 16 in spaced relation thereto. A shaft 26 is suitably journaled at the ends of the frame or housing 10 and carries an elongated cam 28 of nonconductive material which is resilient and deformable so as to yield whenever bodies of diifering thicknesses are interposed between the conductive strips and contact elements between which the conductors of a printed circuit board, tape, or card are engaged. The cam 28, when rotated, is adapted to contact the free ends of the contact elements 18.

As illustrated in FIG. 7, the ends 22 of the conductive strips and contact elements may be mutually insulated so as to provide independent electrical paths to printed circuits on opposite sides of the board or tape employed.

Whereas nylon has been very satisfactory as the cam material for a number of applications of the present invention, other materials displaying the properties of resilience and deformability in conjunction with their ability to insulate electrically are contemplated.

The shaft 26 projects beyond one end of the frame or housing to receive a combined knob and ratchet wheel 30. A sliding pawl 32 is resiliently urged towards the ratchet wheel by means of a leaf spring 34 suitably supported, together with the pawl, in an extension 36 formed at one end of the housing. As shown in FIG. 6, the pawl is in engagement wtih the ratchet wheel 30. When it is desired to retract the pawl from the teeth of the ratchet wheel, the operator will engage the thumb piece 38 carried by the pawl and move it away from the teeth of the ratchet wheel against the force of the leaf spring 34.

The contact elements and conductive strips may be formed with low resistance contacts 40 of beryllium copper, silver, gold or any other material required by a particular installation.

When a printed circuit card, for example, is to be inserted in the connector, the cam 28 will be placed in an elevated position, as that shown in FIG. 3, so that the leaf spring contact elements 18 will be raised by their own resilience to admit the card between them and their opposed conductive strips 16. With the card thus positioned, the combined knob and ratchet wheel 30 will be rotated to cause the cam 28 to urge the free ends of the contact elements 18 into firm engagement with the cardcarried conductors, the pawl 32 engaging the ratchet teeth under the force of the leaf spring 34 to maintain any adjusted position. By virtue of the resilience and deforrnability of the cam coupled with the resilience of the contact elements 18 themselves, it will be clear that good contact will occur even where the dimensions of the cards and their printed circuits vary. To release the card, it is merely necessary that the pawl 32 be retracted against the force of its leaf spring 34, whereupon the card can be withdrawn.

Whereas only one form of the present invention has been described with reference to the accompanying drawings, such variations as will be suggested to those skilled in the art are contemplated by the appended claims.

I claim:

1. An electrical connector comprising a frame of electrical non-conductive material providing a chamber adapted to receive a printed circuit board or the like, said chamber having opposed top and bottom walls forming bearing surfaces and having a back wall, at least one electrical conductive strip secured in place along one of said bearing surfaces and at least one corresponding resilient contact element along the other of said bearing surfaces, supporting means for one end of said resilient contact element, the inherent resilience of said contact element urging a portion thereof, adjacent said supporting means, against said other bearing surface, said resilient contact element having a free end projecting beyond said other bearing surface and overlying, in spaced relation, said corresponding conductive strip, whereby the free end can be flexed toward and away from said conductive strip, a cam having a surface portion of progressively varying radius movably supported with respect to and engageable with the free end of said contact element for urging said element in a direction toward said electrical conductive strip, and means for moving said cam.

2. An electrical connector as defined in claim 1, where:- in said frame supports a ratchet and pawl mechanism for latching said cam in adjusted position.

3. An electrical connector as defined in claim 1, in which said cam is composed of a readily resilient and deformable material.

4. An electrical conductor as defined in claim 1, in which said cam is composed of nylon.

References Cited in the file of this patent UNITED STATES PATENTS 837,501 Plinos Dec. 4, 1906 2,730,683 Ayres et a1. Jan. 10, 1956 2,923,911 Demurjian Feb. 2, 1960 FOREIGN PATENTS 216,045 Switzerland Nov. 17, 1941 629,734 Great Britain Sept. 27, 1949

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