Socket-type multipolar electrical connector

A socket-type multipolar electrical connector having a plurality of contact piece groups and a body made of an insulating material in which said plurality of contact piece groups are assembled, said body having a forward portion defining a rear surface, a center and a rearward portion defining a rear side and bottom;

• a first contact-piece holding hole group having a plurality of first contact-piece holding holes formed in the body and arranged at a plurality of levels in the vertical direction of said body with the horizontal pitch between adjacent holes being fine, said first contact-piece holding holes being adapted such that terminal pins of a plug-type multipolar electrical connector are respectively inserted therein;
• and
• a second contact-piece holding hole group having a plurality of second contact-piece holding holes formed in said body at a lateral side of said first contact-piece holding hole group and arranged at a plurality of levels in the vertical direction of said body with the horizontal pitch between adjacent holes being coarse, said second contact-piece holding holes being adapted such that terminal pins of said plug-type multipolar electrical connector are respectively inserted therein;
• said plurality of contact piece groups comprising:
• a first contact piece group including a plurality of first contact pieces which are disposed in said body at the center thereof with the horizontal pitch between each adjacent contact piece being fine;
• and
• a second contact piece group including a plurality of second contact pieces which are disposed in said body at a lateral side of said first contact piece group with the horizontal pitch between each adjacent contact piece being coarse, wherein:
• the plurality of first contact-piece holding holes are of similar size to the plurality of second contact-piece holding holes;
• the plurality of first contact pieces are fitted in and held in a respective one of said first contact-piece holding holes;
• the plurality of second contact pieces are fitted in and held in a respective one of said second contact-piece holding holes;
• and
• the rearward portion of said body is opened at its rear side and bottom, said body further having:
• rows of vertical ribs for holding the contact pieces, said rows of vertical ribs projecting in the rearward direction from a plurality of vertical and transverse positions of the rear surface of said forward portion, each vertical rib having upper end edges;
• horizontal ribs disposed on each of said vertical ribs and projecting transversely from said upper end edges of a respective vertical rib;
• the rearwardly projecting distances of said row of vertical ribs and said horizontal ribs from said forward portion of said body being gradually reduced in the direction from the highest row of said vertical ribs toward the lowest row of said vertical ribs;
• and
• partitioned spaces defined by said vertical and horizontal ribs respectively communicating with the plurality of first and second contact-piece holding holes.