US Patent 9368909 Electric connector

An electric connector includes a first connector including a first housing in which an inner space is formed, and a second connector including a second housing insertable into the inner space, the first housing including in the inner space a lock engagement portion, the second housing including a lock arm having a lock projection to be engaged with the lock engagement portion, the first housing including in the inner space at least one rib extending in a first direction in which the second housing is inserted into the inner space, the lock arm being formed with a guide space into which the rib is able to be inserted when the second housing is inserted into the inner space.