Contact retention system

#The present invention is directed to electrical connectors and more particularly to a contact retention system for electrical connectors.

#In assembling connectors it is important to provide a structure within the housing or include a device to retain the contacts in the housing. The various ways of retaining the contacts include providing an interference fit within contact receiving passageways of a housing, using outwardly projecting lances on the contacts which abut an internal surface within the passageway or use of a secondary step in manufacturing, such as staking, use of a tool and a high force latch or the like. For cost effective manufacturing, however, it is desirable to eliminate the need for post assembly operations and rely on the structure of the housing and/or contacts to hold the contacts in the housing.

#The problems associated with contact retention are exacerbated when the contacts are loaded into a connector from the mating face thereof and the connector is then mounted to a circuit board or the like. One method of preventing contacts from moving outwardly from the connector is by the use of a tool or removable cover to hold the contacts in place while force is applied to mount the connector to a board, such as disclosed in U.S. Pat. No. 4,396,245. In other cases a secondary manufacturing step, such as using a tool to provide a wall engaging lance in the contact (See FIGS. 11 and 12) is employed after the contacts are inserted into the housing.

#FIG. 1 is a cross sectional view of an electrical connector having the contact retention system of the present invention.

#FIG. 2 is a isometric view of the contact used in the connector of FIG. 1.

#FIG. 3 is a enlarged fragmentary sectional view of the contact passageway portion with the contact removed there from.

#For purposes of illustrating the invention connector 20 is shown as a card edge style connector having contacts 56 with spring arms portions that are prestressed during insertion. It is to be understood that other types of connectors such as those having contacts having spring portions that are anchored in the housing, known in the art as having a "preloaded contact spring or stress" applied during the insertion of the contacts into respective housing passageways. It is to be understood that this retention system and self-seating contact structure may be used with connectors other than card edge connectors.

#FIGS. 1, 2 and 3 illustrate a connector 20 made in accordance with the present invention. Connector 20 includes a housing 22 having a plurality of contacts 56 disposed within respective contact receiving passageways 30 thereof. Housing 22 includes sidewalls 24, assembly face 26, and connecting face 28. Contact receiving passageways 30 extend from the assembly face 26 to the connecting face 28 and include a passageway portion 34 having first and second opposed side surfaces 36, 42 associated with side surfaces 70, 68 of the contact 56 disposed therein. One side surface 36 of each contact receiving passageway 30 includes at least one latching projection 38 extending toward the second passageway side surface 42 defining a forwardly facing stop surface 40 cooperable with a rearwardly facing latch surface 74 on the contact 56. As seen in FIG. 3, the latching projection 38 is at the innermost end of passageway portion 34. The second passageway side surface 42 has at least one second latching projection 44 extending toward the first passageway side surface 36 and defining a rearwardly facing stop surface 46 associated with a forwardly facing latch surface 76 of the contact 56. Contact 56 has opposed side surfaces 58, opposed edges 60 and a selected width. Contact 56 includes a leading end portion 62, a trailing end portion 80 and a intermediate body portion 66. In the embodiment shown, leading end portion 62 includes a connecting section 64 for insertion into through holes of a circuit board (not shown) and trailing end portion 80 includes a contact section 82 for engaging circuit pads on a circuit board (not shown). Intermediate body portion 66 is adapted to be disposed along passageway portion 34 upon full insertion of contact 56 into the housing passageway 30. Intermediate body portion 66 is a generally flat member having opposed body surfaces 68, 70, opposed side edges 72, and opposed end edges 74 and 76. The contact body portion 66 has a dimension wider than the leading and trailing end portions 62, 80 and extends laterally outwardly from at least one edge 60 and define at least one forwardly facing latch surface 76 and at least one rearwardly facing latch surface 74. Preferably body portion 66 extends outwardly from both side edges 60 of contact 56 and define two forwardly facing and two rearwardly facing latch surfaces 76, 74 respectively.

#As can be seen in FIG. 1 the free end 84 of trailing end portion 80 is adapted to be captured behind an internal wall or barrier 25 within the connector housing 22 thereby pre-stressing the spring arm leading end portion 80 with the contact section 82 extending into the cavity proximate the assembly or mating face 26 for mating with pads on a circuit board (not shown).