US Patent 7214090 Connector device

Male connectors (10) are accommodated in an ECU casing C, and connect with female connectors (20) connected with ends of wires (Wa). The male and female connectors (10, 20) are locked together by engaging a lock (45) on a lock arm (40) of the female connector (20) with an engaging portion (47) of the male connector (10). The fracture strength of the engaging portion (47) of the male connector (10) exceeds the fracture strength of the lock (45) of the female connector (20). Thus, an excessive force acting to separate the locked connectors (10, 20) will fracture the lock (45) of the female connector (20) first to cancel the locked state. This avoids fracturing the engaging portion (47) of the male connector (10).