Electrical connectors of the DIN type are known and they include a dielectric housing in which three to eight electrical terminals are molded. The terminals are soldered to electrical conductors of a shielded cable. Metal clamshell members are mounted onto the housing with one of the clamshell members having a U-shaped ferrule that is crimped onto the metal shield of the cable to terminate the shield and provide strain relief. An insulating strain relief member is disposed or molded onto the clamshell members and engages the cable adjacent the U-shaped ferrule thereby holding the clamshell members in position on the housing and providing a strain relief.
Soldering of conductors to terminals is time-consuming and cold solder connections can take place. The crimping of the U-shaped ferrule onto the metal shield does not result in a good termination or an effective strain relief. If the insulating strain relief member is pushed onto the clamshell members, there is not a desirable approach to holding the clamshell members in position. If the insulating strain relief member is molded onto the clamshell members, the open area of the back end of the clamshell members must be covered or have viscous dielectric material positioned therein prior to molding to prevent material of the strain relief member from entering the soldered terminations which may break the terminations.
U.S. Pat. No. 4,493,525 teaches an improved DIN-type connector wherein a pair of metal clamshell members are mounted onto a housing member into which terminals terminated to conductors have already been inserted and secured. One of the clamshells have an inwardly-directed arcuate projection disposed in a U-shaped recess along the housing member; the clamshell members have mating lugs and flange recesses, and together form a forward annular hood shielding and protecting the forward contact sections of the terminals in front of the housing member. The clamshell members are necked down at their rearward ends to smaller U-shaped sections forming an annular member surrounding the wire conductors, and onto the U-shaped sections is positioned the braided metallic shield of the shielded cable. A ferrule member placed loosely on the cable is then brought forward over the braid and the clamshell U-shaped sections and crimped thereto forming an excellent mechanical and electrical connection as well as a cable strain relief, and simultaneously securing the clamshell members onto the housing member.
When used in certain specialized applications, such as for high frequency signals, the plug connector of the prior art having a two-part shell and a small seam or gap between the shell members has a disadvantage in that such a gap causes circumferential discontinuity in the shielding and nonuniform ground current distribution. And especially where the ground terminal of the receptacle engages the metal shell of the plug connector at only one location and therefore to only one of the shell members, the shielding effectiveness of the other shell member is reduced. A further disadvantage of the two-part metal shell is that oxides may form in the small gap which eventually cause a deterioration in shielding effectiveness.
It is desirable to provide an improved DIN-type connector having fewer parts. It is also desirable to provide metal shielding means for such a connector which provides improved, circumferentially continuous, 360-degree shielding capability and also better "hoop" strength. It is further desirable to provide a more simplified method of assembly thereof and of application of such a connector to a shielded cable.
USPTO Backgrounds
USPTO Backgrounds