Multi-pole plug connector with coding elements

Claim 1

A multi-pole plug connector assembly, comprising (a) separate pin and socket housings adapted to be plugged together; (b) pin and socket insert members connected within said pin and socket housings, respectively, said insert members each containing a plurality of electrical contacts which are interconnected when said pin and socket housings are plugged together; and (c) a plurality of fastening screws for connecting said insert members with said housings, respectively, said fastening screws including head portions which comprise coding elements for preventing improper plugging connections between said pin and socket housings, said fastening screw head portions comprising three separate configurations, including (1) a first screw head configuration comprising a cylindrical head having a shorter length and a larger diameter than the remaining screw head configurations; (2) a second screw head configuration comprising a cylindrical head having a longer length and smaller diameter than said first configuration; and (3) a third screw head configuration comprising a cylindrical head having a length corresponding with the length of said second head, an outer diameter corresponding with that of said first head, and an inner diameter slightly greater than the diameter of said second head, whereby when said fastening screws are used to connect said inserts with said pin and socket housings, respectively, said third head is adapted to receive only said second head and the orientation of said different screws will determine the correct plugging of said pin and socket housings to interconnect the sockets thereof.