Cam Actuated Zero Insertion Connector Assembly

1. The Field Of The Invention

The present invention relates to a connector assembly and in particular to an assembly which provides zero insertion force for mating terminals having projecting resilient beams with conductive holes in a circuit board or the like.

2. The Prior Art

Most of the well known electrical connectors require a certain amount of force to accomplish insertion and extraction of the movable contact elements. This force is usually dependent upon the number of contacts being mated as well as the type of contacts. A drawback of high insertion force is not only is there the requirement of overcoming the force itself, but there is undue wear that is accompanied by the high force of the wiping action. Undue wear of this nature is particularly of concern where at least one of the contacting surfaces is plated. Undue wear would, of course, wear through the plating causing either a breakdown in the surface entirely or an open circuit condition.

Various attempts have been made to provide zero insertion mating as evidenced, for example, by U.S. Pat. No. 3,848,222 and others. However, this patent does not concern itself with the particular problem of effecting zero insertion force mating of a plug member with conductive holes in a circuit board or the like.

The present invention is intended to provide a zero or low insertion force connector assembly which can both be mass terminated and used to mate with conductive holes in a circuit board or the like. The plug member of the subject connector assembly has a housing with a plurality of terminal passages extending therethrough from an outwardly open rear end to an enclosed mating face. A like plurality of terminals are each inserted in a respective passage with a beam portion of each terminal projecting from the mating face of the housing and an insulation displacing conductor engaging portion lying in an open rear portion of each passage. The plug member is completed by a pair of hermaphroditic cover members enclosing the rear portion of the housing. A header has means for securing it to a circuit board with walls of the header forming a shroud enclosing an array of conductive holes in the circuit board. A cam is rotatably mounted at one end of the header to act upon one end of the plug member to drive it transversely of the header bringing the beams of the terminals into engagement with the walls of the respective conductive holes.

It is therefore an object of the present invention to produce an improved electrical connector assembly which will provide zero insertion mating of a plug member with plated-through holes of a circuit board or the like.

It is another object of the present invention to produce an improved electrical connector which can be mass terminated and provide for low insertion mating with conductive holes in a circuit board or the like.

It is a further object of the present invention to produce an electrical connector assembly which is mated in a first condition with blades of terminals carried by a plug member extending into but only incidentally contacting walls of conductive holes and then the plug member is driven transversely with respect to the holes to bring the blades into resilient engagement with the holes.

It is a further object of the present invention to provide an improved electrical connector assembly which can be readily and economically manufactured and mass terminated.

The means for accomplishing the foregoing objects and other advantages of the present invention will become apparent to those skilled in the art from the following detailed description taken with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view of the electrical connector according to the present invention;

FIG. 2 is a fragmentary side elevation, partly in section, showing one end of the subject connector assembly in a mated but non-contacting condition;

FIG. 3 is a fragmentary side elevation, partly in section, similar to FIG. 2 showing one end of the subject connector assembly in a mated and fully contacting condition; and

FIG. 4 is a perspective view of one end of the header member of the subject connector assembly with the cam exploded therefrom.

The subject connector assembly 10 has a plug assembly 12 and a header assembly 14 which is mounted on a circuit board 16. The plug assembly 12 includes a housing 18 which is quite similar to the housing 12 disclosed in U.S. Pat. No. 4,243,288, the disclosure of which is incorporated herein by reference. The primary difference between the present housing 18 and that of the patent is the present housing includes a cam abutment 20 on one end and at least one polarizing lug 22, 24 extending laterally from a side surface. The housing 18 has a plurality of passages 26 and a like plurality of transverse apertures 28, each opening into a respective passage. The plug assembly 12 also has a pair of mating hermaphroditic cover members 30, 32 each with a locking leg 34, 36 adapted to engage a shoulder 38 on the oposite cover member. A plurality of terminals 40 are carried by the plug member. Each terminal is similar to that described in U.S. patent application Ser. No. 927,720, filed July 25, 1978 now abandoned, the disclosure of which is incorporated herein by reference, in that they have a rear portion (not shown) which provides mass insulation displacing termination capability for conductors 42. The terminals 40 also include locking lances 44 and projecting resilient cantilever beams 46.

The header assembly 14 is an elongated member of rigid insulative material having a pair of spaced sidewalls 48, 50 defining a plug receiving cavity 52 therebetween. Each sidewall is provided with at least one polarizing slot 54, 56. The base 58 of the header includes downwardly projecting, bifurcated, mounting legs 60, 62. A cam receptacle 64 (see FIG. 4) is formed at one end of the header assembly and receives a substantially cylindrical cam 66 therein. The cam receptacle is generally circular forming an arcuate slot 68 between curved outer wall 70 and a pair of arcuate lugs 72, 74 each having an inwardly directed lip 76. The cam 66 has an arcuate groove 78 which receives the lips 76 of the lugs 72, 74. The cam 66 also has a groove 80 extending parallel to and spaced from the axis of the cam and which allows passage of the cam abutment 20 during mating of the plug assembly 12 into the header assembly 14. The cam 66 also has a driving surface 82 which, upon rotation of the cam, makes engagement with the cam abutment 20. The cam 66 further has a planar profiled flange 84 with steps 86, 88, 90 which engage walls 92, 94 of the receptacle 64 to limit the rotary movement of the cam. The cam further has an axial driving aperture 96, which has been shown as a hexagonal recess receiving a common hex wrench to rotatably drive the cam. Clearly this aperture 96 could be of any shape and could have a driving lever (not shown) associated therewith, either as a separable member or as an integrated portion.

The circuit board 16 includes a plurality of conductive holes 98 in a spaced array as well as mounting apertures 100 located at opposite ends of the array of conductive holes. The holes 98 can either be plated-through holes integral with circuitry on the circuit board, or lined with a grommet or the like making mechanical contact with the circuitry.

The plug assembly 12 of the subject connector is assembled in the manner described in the previously mentioned U.S. Pat. No. 4,243,288 and the conductors 42 connected thereto. The terminated plug assembly is mated with the header assembly by simply inserting the former so that the polarizing lugs 22, 24 slide down in the grooves 54, 56. The cam must be positioned so that the abutment 20 can slide down through the slot 80. When the plug assembly is fully inserted into the header assembly, the beams 46 of the plug assembly will lie within the conductive holes 98 and only be in incidental contact therewith, as shown in FIG. 2. Upon rotation of the cam 66 the plug assembly 12 will be driven transversely of the header assembly 14, to the right in the Figures, so that the beams 46 are brought into contact with the conductive walls of the holes 98, as shown in FIG. 3. The procedure is simply reversed for unmating of the plug assembly.

The present invention may be subject to many modifications and changes without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive of the scope of the invention.