Low inserting force fitting mechanism for electrical connector

Claim 1

A low insertion force connector comprising: a pair of electrical connector housings each having a terminal which are adapted to be connected together by moving one of said connector housings toward another of said connector housings in an insertion direction, said one connector housing having a shaft hole and including: a pair of flexible engagement arms extending in said insertion direction, each of said engagement arms including an engagement claw and a constrictive portion, said constrictive portions being separated by a distance which is smaller than a diameter of said shaft hole, said engagement claw and said constrictive portion being sequentially located in said insertion direction; said other connector housing including a temporary engagement member and a real engagement member which are engageable by said engagement claws, and engagement projections provided in an inner peripheral portion which is aligned with said shaft hole; a rotary shaft including engagement threads and an annular member having a taper portion; and extracting prevention means for preventing said one connector from being disconnected from said rotary shaft, wherein said extracting prevention means includes: a pair of extract prevention projections located orthogonally to said flexible engagement arms; communication grooves corresponding to said extract prevention projections, said communication grooves being provided in said annular member; and an annular groove subsequently engaged with said extract prevention projections and constrictive portion, said annular groove being provided in said rotary shaft.