US Patent 7544081 Electric connector

The second connector 2 has an inner housing 4 and an outer housing 5 that covers the outer peripheries of the inner housing 4, forming a gap S1 for insertion of the first connector 14 therebetween. A receiving cavity S2 is provided for insertion of the mating sensing member 8, and inside which is provided a pair of first stopper projections 51, a second stopper projections 52 and an elastically deformable locking arm 7, front end of which is a free extremity. The locking arm 7 is provides at the front end portion 7C with a pushing portion 72 and a first stopper 74 on each of the two sides. The mating sensing member 8 has a pair of elastically deformable first and second fingers 8A, 8B positioned opposing each other in parallel and they have an actuation portion 80 and a stopper engaging portion 8D.