Abstract: The present invention concerns a connecting device comprising essentially a male connector 1 having an inner sleeve 2 and an outer cylindrical sleeve 3 sliding axially in relation to the inner sleeve. An insulating block 4 placed on the inside of sleeve 2 contains a contact member 6. Small elastic tongues 15 assure the locking in position of a female connector element connectable with a male connector element 1. The sleeve 2 has on its outside a very wide V-shaped groove defining two ramps 23 and 24. The outer sleeve 3 has small elastic tongues 25 whose end have rounded protuberances 26 and tend to return sleeve 3 to a locking position after it has been pushed manually toward the front coupling surface or pulled in the opposite direction.